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The effect of diesel fuel sulphur and vanadium on engine performance and emissions
Abstract
Metallic composition of diesel particulate matter, even though a relatively small proportion of total mass, can reveal important information regarding engine conditions, fuel/lubricating oil characteristics and for health impacts. In this study, a detailed investigation into the metallic elemental composition at different particle diameter sizes has been undertaken. A bivariate statistical analysis was performed in order to investigate the correlation between the metallic element, measured engine performance and engine emission variables. Major sources of metallic elements in the emitted particles are considered in this study, including the fuel and lubricating oil compositions, engine wear emissions and metal-containing dust in the ambient air. Metallic solid ultrafine-particles (Dp < 100 nm) are strongly associated with metallic compounds derived from lubricating oil (Ca, Zn, Mg and K), while the fuel related metallic compounds and engine wear emissions are represented in the https://doi.
... The maximum value for sulphur content of marine fuels used for vessels operating in SECAs was reduced from 1% to 0.1% on 1 January 2015 as seen in Fig. 1. As an alternative to using low-sulphur fuel oil, approved systems for the abatement of emissions, such as SO x (wet and dry) scrubbers are likely to be dominantly used (Chu- Van et al., 2018b). In case these systems for the abatement of emissions are used, the approval of the ship's administration (the flag state) is needed. ...
... A previous on-board measurement found that metals detected in exhaust when using HFO were dominated by compositions from both fuel used (V, Ni, Fe) and lubricating oil (Ca, Zn), while for MGO use, most metals from exhaust emissions were associated with lubricant compositions (Moldanová et al., 2013). These findings are in good agreement with a very recent test-bed study (Chu-Van et al., 2018b). In this study, a detailed investigation into the metallic elemental composition at different particle diameter sizes was undertaken. ...
... The major sources of metallic elements in the emitted particles are considered in this study, including the fuel and lubricating oil compositions, engine wear emissions and metal-containing dust in the ambient air. Solid ultrafine-particles (Dp < 100 nm) are strongly associated with metallic compounds derived from lubricating oil (Ca, Zn, Mg and K), while the fuelrelated metallic compounds and engine wear emissions are represented in the coarse particle fraction (Dp > 1 µm) (Chu- Van et al., 2018b). ...
This study presents an overview of the context and global impacts of recent International Maritime Organization (IMO) regulations on the marine fuel oil refining industry, future marine fuel mix and ship emissions. IMO limited marine fuel sulphur content in both Sulphur Emission Control Areas (SECAs) and Nitrogen Oxide Emission Control Areas (NECAs) to 0.1% (wt. %) by 2015, and to 0.5% globally by 2020. It is anticipated that the newly implemented IMO regulations will help to mitigate negative impact of ship emissions on public health and environment. IMO regulations require significant changes to refineries to increase the production of low sulphur fuels through a shift to distillates, use of novel deep desulphurization techniques, or fuel blending. Changes to the refinery processes can bring forth increases in greenhouse gas emissions and high capital investments. Alternative fuels will need to meet the required reduction of air pollutants and greenhouse gas emissions in coastal areas. Alternative marine fuels consisting of liquefied nature gas (LNG) and biofuel may be suitable fuels to meet both targets. These two fuels are predicted to account for 50% of shipping energy demand by 2050, while the remainder will still be supplied by conventional heavy fuel oil (HFO)/marine gas oil (MGO). Switching to low sulphur fuels as a results of the new IMO regulations has led to measureable reductions in ship emissions generally. This fuel switching also resulted in changes in engine emission characteristics, especially on particulate matter chemical composition.
... As, Cr, Cu, Mn, Ni, and Pb are key species representing coal combustion (Cercasov et al., 1998;Deng et al., 2014;Galvagno et al., 2002;Manoli et al., 2002;Pastuszka et al., 2010;Tian et al., 2010Tian et al., , 2012Weckwerth, 2001;Xia and Gao, 2011;Yang et al., 2003;Zhang et al., 2009), and As, Cu, Mn, and Zn are potential chemical proxies for smelting furnaces and steel smelting (Querol et al., 2006;Yang et al., 2003). Moreover, V and Ni are widely used as indicators of heavy oil combustion, such as that of HFO in ship engines (Cercasov et al., 1998;Chu-Van et al., 2020;Tian et al., 2012Tian et al., , 2013. As illustrated in Table 1, the diagnostic binary ratios of Ni/V collected from LCAS, LTAS, and WAAS were 1.6, 1.2, and 1.0, respectively. ...
... This interpretation is consistent with numerous studies identifying crustal emissions as a major source of Fe (Gaonkar et al., 2020;Lawson and Winchester, 1979). Another prominent feature is the proximity of V, Ti, Ga, and Ni at all observation sites, which may be due to the burning of ship engine HFO coupled with the prevalence of heavy oil combustion at PIE1 factories (Cercasov et al., 1998;Chu-Van et al., 2020;Tian et al., 2012Tian et al., , 2013. ...
... It was assessed from the overall that the concentration of elements increased with rise in engineoperating load. The higher concentrations of trace elements at higher engine-operating loads could be attributed to supply of more fuel oil (diesel) and its consumption in engine cylinder and proportionate rise in usage of lubricating oil compared to lower engine-operating loads (Singh et al., 2006;Chu-Van et al., 2020;Kumbhar et al., 2023). The processes, sources, and factors responsible for contribution of particulate elements during operation of stationary diesel engines could be fuel pyrolysis, engine wear, coating material, pistons, rings, wear/friction of engine parts, cylinder wall friction, utility of lubricating oil, and elemental composition of both fuel and lubricating oils (Shukla et al., 2017;Hao et al., 2019;Patel et al., 2019) The elements of S, Ca, K, Al, Na, Mg, Fe, and Zn contributed as the major components to DPM mass with more than 90 % to total elements at all engine-operating loads for ten sizes of PM. ...
The mass concentration of diesel particulate matter (DPM) and its elemental constituents (twenty-four) emitted from stationary diesel engine exhaust at ten different sizes (56 nm to 18 µm) increased with rise in engine-operating load. The maximum value of DPM concentration varied from 10.3 ± 2.4 mg/Nm3 at 0% load to 20.4 ± 6.5 mg/Nm3 at 100% load at size-bin of 0.10–0.18 μm. The elements of S, Ca, K, Al, Na, Mg, Fe, and Zn contributed as the major components to DPM mass with more than 90% to total elements at six engine-operating loads. Ca, K, Al, Na, and Mg also showed higher values of EFs compared to Fe, Zn, As, Cr and Ni. Compared to Cu, Mn, Co, Se, Pb, Ba, Sr, fuel-based emission factor (EF) of Ti, Ga, Cd, Bi, and Te showed lower side of the estimated values. The levels of hazardous particulate elements generated from stationary diesel engine exhausts was a matter of concern from human health point of view as these elements showed better potential in causing significant cancer and non-cancer diseases through long-term exposure. The elements in DPM revealed significant deposition in the pulmonary and alveolar region of the human respiratory tract.
... High levels of carbon (OC), black carbon (EC/BC), ash, and heavy metals are a large contributor to emissions (Chu- Van et al., 2020). Many types of biodiesel have been studied, such as biodiesel from waste cooking oil (WCO) (Suanggana & Said, 2023;Suardi et al., 2023a;Desiyana et al., 2014;Sinaga et al., 2014), biodiesel from corn (maize) oil (Suardi et al., 2023b), biodiesel production from castor oil (Suardi et al., 2023c), biodiesel from algae (Azeez et al., 2021), and biodiesel from coconut oil (Pramitha et al., 2016). ...
To address the challenges faced by the government in the realm of petroleum imports, a promising strategy was adopted in the utilization of biodegradable and renewable sources of biodiesel, such as coconut oil. This research employed two distinct methodologies: Transesterification for biodiesel synthesis and a comprehensive assessment of fuel properties. Subsequently, an experimental phase assessed biodiesel within an engine environment to analysis performance metrics. Results showed that B30 (30% coconut oil, 70% diesel oil) has density of 0.850 g/cm³, B50 (50% coconut oil) at 0.861 g/cm³, and B100 (Pure coconut oil) at 0.893 g/cm³. The values differed from regional standards. As per ASTM D6751, B30 has a viscosity of 2.31 cSt, B50 3.22 cSt, and B100 is 7.02 cSt. Engine performance revealed B50 with the highest torque at 11.787 Nm, while B0 (pure hydrocarbon diesel) has a thermal efficiency of 38%. B0's lowest SFC (Specific Fuel Consumption) is 261.12 g/kWh at 2000 watts load and 1000 rpm. Biodiesel coconut oil provided comparable power and torque (0.3% difference from B0) but consumed more fuel (21.6 % higher usage than B0).
... High levels of carbon (OC), black carbon (EC/BC), ash, and heavy metals are a large contributor to emissions (Chu- Van et al., 2020). Many types of biodiesel have been studied, such as biodiesel from waste cooking oil (WCO) (Suanggana & Said, 2023;Suardi et al., 2023a;Desiyana et al., 2014;Sinaga et al., 2014), biodiesel from corn (maize) oil (Suardi et al., 2023b), biodiesel production from castor oil (Suardi et al., 2023c), biodiesel from algae (Azeez et al., 2021), and biodiesel from coconut oil (Pramitha et al., 2016). ...
To address the challenges faced by the government in the realm of petroleum imports, a promising strategy was adopted in the utilization of biodegradable and renewable sources of biodiesel, such as coconut oil. This research employed two distinct methodologies: Transesterification for biodiesel synthesis and a comprehensive assessment of fuel properties. Subsequently, an experimental phase assessed biodiesel within an engine environment to analysis performance metrics. Results showed that B30 (30% coconut oil, 70% diesel oil) has density of 0.850 g/cm³, B50 (50% coconut oil) at 0.861 g/cm³, and B100 (Pure coconut oil) at 0.893 g/cm³. The values differed from regional standards. As per ASTM D6751, B30 has a viscosity of 2.31 cSt, B50 3.22 cSt, and B100 is 7.02 cSt. Engine performance revealed B50 with the highest torque at 11.787 Nm, while B0 (pure hydrocarbon diesel) has a thermal efficiency of 38%. B0’s lowest SFC (Specific Fuel Consumption) is 261.12 g/kWh at 2000 watts load and 1000 rpm. Biodiesel coconut oil provided comparable power and torque (0.3% difference from B0) but consumed more fuel (21.6 % higher usage than B0). Keywords: Biodiesel, Coconut oil, Engine performance, Fuel properties, Transesterification.
... Non-exhaust emissions are from fuel volatilization, wear and sediment re-suspension, etc. (Dahl et al., 2006;Jansson et al., 2010;Niemann et al., 2020;Ramirez et al., 2020;Vu et al., 2015). Volatilization of motor vehicle fuels and lubricants can produce UFP, while very little research has been done on sediment resuscitation, and the effect of this process on UFPs is unclear (Chu- Van et al., 2020;Jayaratne et al., 2012;Morawska et al., 2008). In terms of the impact of wear, brake wear particles come from the wear of the brake lining (pad) and the rotor (disc) or drum, and at higher temperatures, the wear process formed between the friction pad and the rotor or drum can produce UFPs Wahlström et al., 2010). ...
Identifying and quantifying the sources and clarifying the impacts of ultrafine particles (UFP) in the complicated urban environments are important for particle pollution control and UFP-climate interaction understanding. The previous studies have made notable contributions to these aspects and it is necessary to review the achievements. Here, the characteristics of traffic emissions and new particle formation (NPF) events/processes and their effects on urban UFP are summarized mainly based on the latest progresses. The constantly improved techniques of measuring UFP have played a vital role for knowing the sources and impacts of UFP. Meanwhile, the emissions inventories, dispersion models, and receptor models generally perform better when working together and using high resolution input and corrected algorithms. Besides, the interaction between UFP and climate is discussed mainly by linking radiation, cloud condensation nuclei, particle deposition, and the environmental conditions required for nucleation processes. Although for urban UFP, there are consensuses that traffic emissions and nucleation processes are two main sources and UFP and climate interact mainly via radiation and cloud condensation nuclei (CCN), there are many other crucial tasks for future and this work lists seven of them. They involve, scientifically, how much other sources such as industrial and regional sources mix with traffic emissions and nucleation processes in source contributions and how primary pollutants collaborate with UFP (aerosols) in aerosol-climate interactions; and engineeringly, how to improve the integration of the instruments and the instrument customization services according to actual situations. These progresses and future perspectives would help in more accurately quantifying the contributions of emissions and nucleation processes to UFP and better evaluating the impacts of UFP. Despite our efforts, knowledge on the main sources and impacts of urban UFP is limited and detailed solutions for the future tasks are missing here, which need joint efforts from UFP and related fields.
... Several of these elements are sourced from general vehicle wear; copper (Cu), cadmium (Cd), and zinc (Zn) are known to disperse from brake linings, brake pads and tyre wear, and Zn may additionally be sourced from the corrosion of galvanised safety barriers and similar structures (Ward, 1990;Legret and Pagotto, 1999). Some multielement contamination may also stem from fuel drips and spillages; as well as typical hydrocarbons, petroleum and diesel can also contain a range of different trace metals including Cu, Pb, vanadium (V), and Zn (Chu- Van et al., 2020). Additional diffuse sources of some elements include vehicle emissions, drips of crankcase oil, and wear of asphalt road surfaces (Brown and Peake, 2006). ...
Underpasses or road tunnels are increasingly installed to reconnect habitats and ensure safe wildlife passage, thus preventing habitat fragmentation caused by roads and mortality from collisions with vehicles. In the UK, such underpasses are regularly implemented for amphibians and especially the protected great crested newt, Triturus cristatus. However, roads are also a key source of environmental pollutants including trace metals, road salt, petroleum and diesel hydrocarbons and these might impact road mitigation structures where amphibians are funnelled to, yet the extent and implications of such pollutants are almost never quantified in relation to this aspect, despite the recognised sensitivity of amphibians to chemical pollutants. Sediments were analysed from four amphibian road mitigation tunnel sites across the UK and compared to natural soil formations at local reference sites to determine whether contaminants were indeed accumulating within the tunnels. Three potential contaminants (copper, lead, and total petroleum hydrocarbons) were found in greater concentrations in the underpass sediments than respective reference sites at three of four locations, while one (zinc) was found in greater concentrations at all four studied underpasses compared to reference sites. Aggregated sediment pH value was significantly greater in the underpass sediment than the respective reference sites at all four study sites and in several instances the contaminants reached values that exceeded the thresholds of environmental concern. Despite the large geographic area covered and the significant site differences the absolute values of potential pollutants in tunnels were similar across sites, thus suggesting similar pollution sources and pathways. These results suggest road tunnels installed for ecological mitigation could be a significant pathway for pollutants from road surfaces to amphibians and it is recommended that focussed monitoring and maintenance of the underpasses is enacted given that their short or long-term impacts on amphibians are currently unknown. Potential management options could include regular jet-washing of the underpasses, or alternatively, pre- or post-implementation modifications of mitigation designs should aim to minimise the pollution pathway from road surfaces.
... PM of marine vessels and engines mainly comes from incomplete combustion of diesel fuels [8]. Mass PM emission leads to severe pollution and affects engine efficiency. ...
Different from vehicle engines, Diesel Particulate Filter (DPF) inactivation is an unavoidable issue for low-speed marine diesel engines fueled with Heavy Fuel Oil (HFO). This paper introduced a sulfur resisting material in Silicon Carbide (SiC)-DPF to improve DPF performance. The results of bench-scale experiments showed that the Balance Point Temperature of the modified DPF module was 300°C and DPF modules had a good filtration performance, with Particulate Matters (PMs) residual being less than 0.6 g per cycle. In pilot-scale tests, PMs emissions of unit power decreased with engine load going up, filtration efficiency of nucleation mode PMs being only 36% under 100% load, while DPF still had a good performance in accumulation mode PMs control, being 94.2% under the same load. DPF modules showed excellent regeneration durability in the 205h endurance test, with a regeneration period of 1.5-2h under 380°C. There was no obvious degeneration in the DPF module structure, with no cracks or breakage. Besides, the DPF module could also control gaseous emissions, total emissions decreased by 10.53% for NO and 57.19% for CO, respectively. The results suggested that introducing sulfur-resisting material in DPF could greatly improve the DPF performance of low-speed marine diesel engines fueled with HFO.
... Particulate emissions consist sulphate, organic matter (OM), black carbon (BC), ash and elemental carbon (EC) (Di Natale and Carotenuto 2015). Sulphate aerosol formation is followed after emitted SO 2 and sulphur trioxide (SO 3 ) (Chu Van et al. 2019;Chu-Van et al. 2020). Unlike black carbon, SO 2 aerosols have a positive impact on humanity regarding global warming by reflecting sunlight (Poljanac et al. [date unknown]). ...
Although there are some studies on the impact of Sulphur 2020 on shipping in the literature, large-scale economic analyses are scarce. For this reason, in compliance with sulphur abatement, this study aims to determine the most economical alternatives for shipping companies. First, real data are collected from the maritime industry and scenarios are created regarding different ship types, engine powers, sailing times and fuel prices. In conclusion, using very low sulphur fuel oil alternative for dry cargo ships, hybrid scrubber alternative for crude oil tankers, open-loop scrubber alternative for container ships and hybrid scrubber for Ro-Ro ships are found as economically beneficial in most cases. Last of all, the break-even time from low sulphur fuels to scrubber types is presented to guide shipowners in finding the best alternative with respect to ship ages.
... V is a tracer of fuel oil emissions, in particular from thermoelectric power plants; it has toxic and carcinogenic effects on human beings (Venkataraman and Sudha 2005). Other sources are metal processing industries and diesel vehicles (Chu- Van et al. 2020). This way, Fig. 11 presents V elemental concentrations measured since 1990, at different sampling locations in the MAMC (Miranda et al. 1994(Miranda et al. , 1996(Miranda et al. , 2000(Miranda et al. , 2004(Miranda et al. , 2005Paredes-Gutiérrez et al. 1997;Vega et al. 2004;Querol et al. 2008;Mugica et al. 2009;Barrera et al. 2012;Díaz et al. 2014;Morton-Bermea et al. 2021), together with the mean concentrations measured in this work. ...
The results of a study of the elemental concentrations in PM10 samples collected at a site in southwest Mexico City during 2016 and 2019, are presented. The concentrations of up to 19 elements were measured with X-ray fluorescence (XRF). These analyses were complemented with ion chromatography for eight ionic species (for the samples collected in 2016). The behaviors of the gravimetric mass and elemental concentrations are described for the morning, afternoon, and night-time periods in 2019. The elemental concentrations observed in the PM10 samples did not present significant changes as compared to those published in previous works. It was found that the gravimetric mass concentrations were always below the official standards, except during a contingency period in May 2019. The positive matrix factorization (PMF) receptor model was used to identify contaminating sources and their relative contributions to the concentrations of the detected elements. The soil-related factors were the most abundant contributors, with other components associated to traffic, biomass burning, fuel oil, secondary aerosol, and dust resuspension. The occurrence of episodes in 2019 is explained with the aid of PMF and back-trajectories, while the contingency period is due to other chemical species not detected in PM10 with XRF. A comparison with data collected in 2005 in downtown Mexico City is also carried out, as well as with urban areas in other countries.
... Therefore, the proportion of LNG-fueled ships is steadily increasing. The 72 LNG-fueled container vessels currently under construction [32] indicate the huge potential for the future development of LNG-fueled ships [33]. ...
Ships are an important part in international trade transportation and a major source of pollution. Therefore, the International Maritime Organization (IMO) implemented an amendment to the International Convention for the Prevention of Pollution from Ships (MARPOL) Annex VI, which stipulates that the sulfur content in marine fuel oil shall not exceed 0.5 wt.% starting in 2020. In order to meet the IMO low sulfur policy, shipping lines could adopt one of the following strategies: (1) using very low sulfur fuel oil (VLSFO), i.e., with sulfur content less than 0.5 wt.%; (2) installing scrubbers or other exhaust gas aftertreatment systems; or (3) replacing current fuels with clean alternative fuels such as natural gas. This study evaluates the feasibility and benefits of these strategies for shipping lines in order to determine the most cost-effective measures. First, according to the feasibility of the strategies evaluated by SWOT analysis, although scrubbers can reduce emissions of sulfur oxides into the atmosphere, more and more countries are restricting the discharge of wastewater from open-loop scrubbers into their waters. Instead, VLSFO and liquefied natural gas (LNG) are good choices in terms of environmental protection and economic benefits. Therefore, this study further evaluates the two strategies of replacing high sulfur fuel oil (HSFO) with VLSFO and converting diesel engines to LNG engines based on a cost-benefit methodology. This study took an 8500 TEU container vessel, which is powered by a marine diesel engine with the nominal power of 61,800 kW, sailing the Asian-European route as an example, and calculated the total incremental costs, pollutant emission reductions, and cost benefits arising from the implementation of the VLSFO and LNG strategies, respectively. According to the results of this study, the total incremental cost of LNG is higher than that of VLSFO in the first 4.7 years, but this gradually decreases, making the gap of the total incremental costs between the two strategies wider year by year. In comparison with using HSFO without any improvement, the total incremental costs of the VLSFO and LNG strategies increase by 12.94% and 22.16% over the following five years, respectively. The use of LNG can significantly reduce SOx, PM, NOx, and CO2 emissions; on the other hand, it leads to more CH4 emissions than the VLSFO strategy. Compared to doing nothing, the cumulative reduction rates of SOx, PM, NOx, and CO2 emissions over the next five years after the adoption of the LNG strategy are 3.6%, 7.0%, 70.4%, and 15.7%, respectively. The higher emission reduction rates of LNG compared to VLSFO illustrate that the former has a good effect on the suppression of exhaust gas pollution. In terms of the cost-benefit evaluation of the two strategies, this study shows that the VLSFO strategy is more cost-effective than the LNG strategy in the first 2.5 years, but that the cost-benefit ratio of the latter increases year by year and exceeds that of the former, and the gap between them widens year by year. Based on the evaluation results of this study, the LNG strategy is suitable for ocean-going container vessels with fixed routes and younger or larger sized vessels to meet the IMO low sulfur policy. In contrast, the VLSFO strategy is appropriate for old merchant ships with fewer container spaces. LNG is a suitable medium- and long-term strategy, i.e., for more than 2.5 years, for shipping lines to meet the IMO low sulfur policy, while VLSFO is a suitable short-term strategy.
Introduction. During the operation of heavy-duty diesel equipment in areas with a low-temperature climate, engine oils are contaminated by coolant and water. The ingress of these substances into the lubricant leads to a deterioration in its quality indicators, which subsequently leads to problems in the nodes of the internal combustion engine.
Relevance. The deterioration of the values of engine oil quality indicators is directly related to the presence of water and coolant in it. It is not always possible to objectively track the ways of leakage of these pollutants, and this, in turn, leads to serious consequences in the form of wear of the contacting surfaces of engine parts, corrosion. It is also important to evaluate the resource of lubricant additive packages due to its dilution with water and antifreeze.
Materials and methods. This paper presents the results of a literature review aimed at studying the ways of coolant and water ingress during the operation of diesel engines, their influence on the physical and chemical properties of motor oils. The brief information about the composition of the coolant is indicated.
Conclusions. The ingress of water and coolant into the engine oil leads to an increase in the kinematic viscosity of the lubricant, as well as to the formation of deposits on the surfaces of the engine friction pairs. In addition, spherical compounds appear in the crankcase of the engine, which are a combination of destroyed additive packages and glycol. Oil change intervals must be monitored at an increased rate of water and coolant entering the engine oil.
Scope of the study / possibility. This type of study will help to determine the causes of penetration of water and coolant into the crankcase space, to understand the consequences of using engine oil contaminated with water and coolant.
Originality / value. The conducted research can be the basis for the development of recommendations for improving the maintenance of internal combustion engines for enterprises that have at their disposal cars with diesel engines in order to increase the resource of power units and reduce operating costs.
The Metropolitan Area of São Paulo (MASP) is among the largest urban areas in the Southern Hemisphere. Vehicular emissions are of great concern in metropolitan areas and MASP is unique due to the use of biofuels on a large scale (sugar-cane ethanol and biodiesel). In this work, tunnel measurements were employed to assess vehicle emissions and to calculate emission factors (EFs) for heavy-duty and light-duty vehicles (HDVs and LDVs). The EFs were determined for particulate matter (PM) and its chemical compounds. The EFs obtained for 2018 were compared with previous tunnel experiments performed in the same area. An overall trend of reduction of fine and coarse PM, organic carbon (OC), and elemental carbon (EC) EFs for both LDVs and HDVs was observed if compared to those observed in past years, suggesting the effectiveness of vehicular emissions control policies implemented in Brazil. A predominance of Fe, Cu, Al, and Ba metals emission was observed for the LDV fleet in the fine fraction. Cu presented higher emissions than two decades ago, which was associated with the increased use of ethanol fuel in the region. For HDVs, Zn and Pb were mostly emitted in the fine mode and were linked with lubricating oil emissions from diesel vehicles. A predominance in the emission of three- and four-ring polycyclic aromatic hydrocarbons (PAHs) for HDVs and five-ring PAHs for LDVs agreed with what was observed in previous studies. The use of biofuels may explain the lower PAH emissions for LDVs (including carcinogenic BaP) compared to those observed in other countries. The tendency observed was that LDVs emit higher amounts of carcinogenic species. The use of these real EFs in air quality modeling resulted in more accurate simulations of PM concentrations, showing the importance of updating data with real-world measurements.
Combustion ignition (CI) engines for nonroad vehicles such as railway engines and marine engines provide greater output power with better fuel efficiency at a low cost. This has led to a rise in the use of such engines and made them popular over the decades. At the very exhaust of these engines, dangerous pollutants emitted are nitrogen oxides (NOx), hydrocarbons (HC), carbon monoxide (CO) and particulate matter (PM). These emissions are proving to be fatal for nature as well as human health. This paper focusses on the importance of nonroad combustion ignition engines of power 560 kW or more, its effects on environment and reviewing previous solutions. The upcoming challenges and new ideas to reduce these pollutants are also discussed with adherence to the new environmental norms and policies adopted by different countries. Currently, aftertreatment technology is prominent in reducing these pollutants but as these policies are getting stringent, will this technology be efficient in the long run? Therefore, possible improving factors are suggested in this paper to extract 90% or more efficiency from the aftertreatment systems. The pollutant reduction methods that are reviewed are exhaust gas recirculation (EGR), lean NOx trap (LNT), diesel oxidation catalyst (DOC), diesel particulate filter (DPF) and selective catalytic reduction (SCR). Recently, many scientists are trying to find different alternate fuels such as blends of biodiesel and develop electric powertrains to eliminate these pollutants. The sole purpose of this review is to concentrate on the current capabilities and the possible improvements of the existing pollutant reduction techniques with respect to nonroad diesel engines and also provide a future perspective with the help of alternate fuels.
This study characterized the chemical composition of particulate matter from light- (LDV) and heavy-duty (HDV) vehicles based on two traffic tunnel samplings carried out in the megacity of São Paulo (Brazil), which has >7 million vehicles and intense biofuel use. The samples were collected with high-volume samplers and analyzed using chemical characterization techniques (ion and gas chromatography, thermal-optical analysis, and inductively coupled plasma mass spectroscopy). Chemical source profiles (%) were calculated based on the measurements performed inside and outside the tunnels. Identifying a high abundance of Fe and Cu for traffic-related PM in the LDV-impacted tunnel was possible, linked with the emission of vehicles powered by ethanol and gasohol (gasoline and ethanol blend). We calculated diagnostic ratios (e.g., EC/Cu, Fe/Cu, pyrene/benzo[a]pyrene, pyrene/benzo[b]fluoranthene, and fluoranthene/benzo[b]fluoranthene) characteristic of fuel exhausts (diesel/biodiesel and ethanol/gasohol), allowing their use in the assessment of the temporal variation of the fuel type used in urban sites. Element diagnostic ratios (Cu/Sb and Fe/Cu) pointed to the predominance of LDVs exhaust-related copper and can differentiate LDVs exhaust from brake wear emissions. The carbonaceous fraction EC3 was suggested as an HDV emission tracer. A higher total polycyclic aromatic hydrocarbons (PAHs) fraction of traffic-related PM2.5 was observed in the HDV-impacted tunnel, with a predominance of diesel-related pyrene and fluoranthene, as well as higher oxy-PAHs (e.g., 9,10-anthraquinone, associated with biodiesel blends) abundances. However, carcinogenic species presented higher abundances for the LDV-impacted tunnel (e.g., benzo[a]pyrene). These findings highlighted the impact of biofuels on the characteristic chemical species ratios and pointed to possible markers for LDVs and HDVs exhausts.
Soot particles with sulfur functional groups (SFGs) are one of the main concerns from shipping emissions, especially when they are produced from fuel combustion with high fuel sulfur content (FSC). The present study investigates the physicochemical characteristics of soot particles generated from different FSC fuels on a marine auxiliary diesel engine. A comprehensive set of experimental techniques including Fourier transform infrared (FT-IR), inductively coupled plasma optical emission spectroscopy (ICP-OES), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA) are employed to characterize SFGs, chemical elements, morphology, nanostructure, volatile organic fraction (VOF) content and oxidation behavior, respectively. Results reveal that, FSC has negligible influences on combustion performance, yet its high content increases the concentrations of SFGs (–SH, C–S–S, C–S, SO4²⁻) and sulfur element VOF content and primary particle size (dp) of soot particles. Linear correlations between soot fringe length (La), oxidation activation energy (Ea) and relative concentrations of –SH and C–S are observed, respectively. Higher relative concentration of C–S bond corresponds to shorter La. The relative amounts of –SH and C–S could improve soot oxidation reactivity, associated with lower Ea. In addition, metal-sulfates are formed from the combination of SO4²⁻ with metal elements contained in fuel or lube oils, among which CaSO4 is shown an enhancing factor for soot oxidation.
Selective catalytic reduction (SCR) technology is currently the most effective deNOx technology and has broad application prospects. Moreover, there is a large NOx content in marine engine exhaust. However, the marine engine SCR catalyst will be affected by heavy metals, SO2, H2O(g), hydrocarbons (HC) and particulate matter (PM) in the exhaust, which will hinder the removal of NOx via SCR. Furthermore, due to the high loading operation of the marine engine and the regeneration of the diesel particulate filter (DPF), the exhaust temperature of the engine may exceed 600 °C, which leads to sintering of the SCR catalysts. Therefore, the development of new catalysts with good tolerances to the above emissions and process parameters is of great significance for further reducing NOx from marine engines. In this work, we first elaborate on the mechanism of the SCR catalyst poisoning caused by marine engine emissions, as well as the working mechanism of SCR catalysts affected by the engine exhaust temperature. Second, we also summarize the current technologies for improving the properties of SCR catalysts with the aim of enhancing the resistance and stability under complex working conditions. Finally, the challenges and perspectives associated with the performance optimization and technology popularization of marine SCR systems are discussed and proposed further. Consequently, this review may provide a valuable reference and inspiration for the development of catalysts and improvement in the denitration ability of SCR systems matched with marine engines.
The conventional NH3-SCR catalysts always demonstrated a low activity at high temperature (≥600 °C), which is a common situation in the exhaust gas of diesel engine. A series of W-Zr-ZSM-5 (WZZ) catalysts were prepared by sol–gel method (SG), impregnation method (IM), and grinding method (GR), respectively, to achieve the goals for NO removal at high temperature. It found that WZZ-SG700 prepared by SG method demonstrated the highest NO conversion among the three preparation methods, exhibiting >90% NO conversion at 300–650 °C. The characteristics of the catalysts were analyzed by the techniques of XPS, SEM, H2-TPR, NH3-TPD, BET, XRD and in-situ DRIFTS. It found that the interaction between WO3 and ZrO2 significantly enhanced the surface acidity and redox property of the catalysts, which was beneficial to the performance at high temperature. Furthermore, the catalyst prepared by SG method (WZZ-SG700) had a higher surface enrichment of W/Zr on a higher BET surfaces area when compared with IM and GR methods. It resulted in the formation of a more acid site of the catalyst and a higher redox property, exhibiting a higher NO conversion especially at high temperature. In addition, WZZ-SG700 catalyst showed a high resistance of SO2 & H2O and a high N2 selectivity. The in-situ DRIFTS studies revealed that the NO removal over WZZ-SG700 catalyst conformed to L-H mechanism, and the species of monodentate nitrite, ad-NO2 species, NH⁴⁺, surface-adsorbed NH3 and amide (–NH2) were the main reaction intermediates appearing on the surface of the catalyst during the reaction. WZZ-SG700 demonstrated to be a promising catalyst for the diesel engine SCR system at high temperature.
Surrogate fuels for hydrothermal liquefaction (HTL) algae biocrude depicting its nitrogen (N) and sulphur (S) content were simulated in this study and tested in a multi-cylinder diesel engine. The influence of N and S presence in the fuel on its combustion behaviour and emissions profile was investigated. To our knowledge, N and S-containing fuels in reference to HTL algae biocrude, have not been reported in an internal combustion engine in the literature, which is the unique and novelty of the current work. The presence of N and S in the fuel affected its physical properties. The density of the surrogate fuel was slightly higher than that of diesel, while viscosity, in general, was maintained. The flash point of the N and S-fuel was reduced in the presence of N. N had a stronger effect than S in reducing the lower heating value (LHV) of the surrogate fuel than that of diesel. Compared to diesel, emissions of both carbon monoxide (CO) and unburned hydrocarbons (HC) were lower for N and S-containing fuels. Increasing nitrogen oxides (NOx) and sulphur dioxide (SO2) emissions were observed with increasing N and S content, respectively, in the fuels. A significant increase in particle mass (PM) emissions was observed at high concentrations of N (4.5 wt.%) and S (0.2 - 0.4 wt.%). Such values of S are found in some off-road and marine applications. Therefore, HTL biofuel can be a low-sulphur alternative fuel for shipping industry because its fuel properties similar to that of bunker fuel.
Oversupply, extra energy consumption, and CO2 emissions from the refinery of biodiesel-derived glycerin (G) led to the consideration of its use as an alternative fuel. In this study, a nonroad diesel engine generator was employed to represent potential emissions under stringent regulated standards. G-diesel has been reported to reduce nitrogen oxides (NOx) and soot levels but increase CO and hydrocarbon emissions. A bio-producible acetone-butanol-ethanol (ABE) solution with multiple polarities was added to stabilize the glycerin and water in diesel examined in this study. A series of ABE-G-diesel blends were prepared to form the thermostable microemulsions. Four blends with small and well-dispersed bubbles were tested in the engine generator. The specific thermal efficiencies of the engine were slightly improved by using ABE-G from regular diesel due to better spray quality, longer ignition delay, and fuel-oxygen content that would enhance combustion. Meanwhile, the PM-NOx-CO emission trade-off in the previous study has been overcome by using ABE-G-diesel since the better fuel atomization and more premixed combustion were approached, as well as the lower and homogeneous in-cylinder temperature caused by water content and micro-explosion. However, the condensable particulate matter and nitro-PAHs were also observed and realized their unignorable contribution, which has not been regulated and even researched for the generators. Fortunately, the new fuels could inhibit both of them to a certain degree. Consequently, this study proposes using recyclable glycerin with a simple pretreatment mixed with ABE and diesel for greener nonroad diesel engine especially those equipped with low-grade aftertreatment.
The corrosion behaviors of a combined weld (plasma, gas tungsten arc) joint in a super austenitic stainless steel pipe were investigated using a range of experimental and analytical methods. To ensure superior corrosion resistance, a Ni-based super alloy (Inconel 625) was employed as the welding material only in the gas tungsten arc welding (GTAW). Nevertheless, pitting corrosion occurred preferentially around the sigma phase which had been precipitated in the interdendritic region of the GTAW. This indicated that the Inconel 625, which has a higher pitting resistance equivalent number (PREN), became even more susceptible to pitting corrosion than the base metal (BM). The higher Fe content in the Inconel 625 due to the dilution of Fe, supplied by the leading plasma arc welding, may increase the driving force for the precipitation of sigma phase. It was also revealed that the post weld heat treatment conducted at 1050~1150 oC effectively reduced the fraction of sigma phase precipitated in the weld. Even after such heat treatment, however, pitting corrosion occurred unexpectedly in the center region of the BM. This may be due to additional precipitation of the sigma phase in the BM, caused by inadequate control of the cooling rate during heat treatment at the industrial site.
International Convention for the Prevention of Pollution from Ships (MARPOL) is an international agreement, signed in 1973 and amended in 1978, to prevent pollution of seas from ship-based waste. In this review study, the Annex IV (Prevention of Pollution by Sewage from Ships) and Annex VI (Prevention of Air Pollution from Ships) contents of this agreement, which contains six annexes, are examined and changes in the focus of past studies and current studies are examined. Within the scope of Annex IV, the treatment procedures before the discharge of ship-based sewage wastes, special zones for wastewater discharge, and studies on the dilution of wastewater at sea after discharging were discussed. Within the scope of Annex VI, studies on emission inventory development, new technologies and alternative fuels have been examined. As a result of the review, the progress of the related studies has been evaluated and the future projections, which focused on the possible tendency of the studies, have been propounded.
Emissions from ships at berth are small compared to the total ship emissions; however, they are one of the main contributors to pollutants in the air of densely-populated areas, consequently heavily affecting public health. This is due to auxiliary marine engines being used to generate electric power and steam for heating and providing services. The present study has been conducted on an engine representative of a marine auxiliary, which was a heavy duty, six-cylinder, turbocharged and after-cooled engine with a high pressure common rail injection system. Engine performance and emission characterisations during cold start are the focus of this paper, since cold start is significantly influential. Three tested fuels were used, including the reference diesel and two IMO (International Maritime Organization) compliant spiked fuels. The research engine was operated at a constant speed and 25% load condition after 12 hours cooled soak. Results show that during cold start, significant heat generated from combustion is used to heat the engine block, coolant and lubricant. During the first minute, compared to the second minute, emissions of particle number (PN), carbon monoxide (CO), particulate matter (PM), and nitrogen oxides (NOx) were approximately 10, 4, 2 and 1.5 times higher, respectively. The engine control unit (ECU) plays a vital role in reducing engine emissions by changing the engine injection strategy based on the engine coolant temperature. IMO-compliant fuels, which were higher viscosity fuels associated with high sulphur content, resulted in an engine emission increase during cold start. It should be taken into account that auxiliary marine diesel engines, working at partial load conditions during cold start, contribute considerably to emissions in coastal areas. It demonstrates a need to implement practical measures, such as engine pre-heating, to obtain both environmental and public health advantages in coastal areas.
The main sources of particulate emissions from engines are fuel and lubricating oil. In this study, particles emitted by a medium speed diesel engine for locomotive use were characterized chemically by using a Soot Particle Aerosol Mass Spectrometer (SP-AMS). Additionally, positive matrix factorization (PMF) was applied to the SP-AMS data for the separation of fuel from lubricating oil and/or oil additives in diesel engine emissions. The mass spectra of refractory species, i.e. metals and rBC, were included in the PMF input matrix in addition to organics in order to utilize the benefit of the SP-AMS to measure non-refractory and refractory species. In general, particulate matter emitted by the diesel engine was dominated by organics (51%) followed by refractory black carbon (rBC; 48%), trace metals and inorganic species (1%). Regarding the sources of particles, PMF indicated four factors for particle mass of which two were related to lubricating oil-like aerosol (LOA1, 29% and LOA2, 24%) and two others to diesel-like fuel aerosol (DFA1, 35% and DFA2, 12%). The main difference between LOA1 and LOA2 was the presence of soot in LOA1 and metals in LOA2 factors. DFA factors represented burned (DFA1) and unburned fuel (DFA2). The results from the PMF analysis were completed with particle size distributions, volatility measurements and particle morphology analyses.
In 2016, the International Maritime Organization (IMO) decided on global regulations to reduce sulphur emissions to air from maritime shipping starting 2020. The regulation implies that ships can continue to use residual fuels with a high sulphur content, such as heavy fuel oil (HFO), if they employ scrubbers to desulphurise the exhaust gases. Alternatively, they can use fuels with less than 0.5% sulphur, such as desulphurised HFO, distillates (diesel) or liquefied natural gas (LNG). The options of lighter fuels and desulphurisation entail costs, including higher energy consumption at refineries, and the present study identifies and compares compliance options as a function of ship type and operational patterns.
The results indicate distillates as an attractive option for smaller vessels, while scrubbers will be an attractive option for larger vessels. For all vessels, apart from the largest fuel consumers, residual fuels desulphurised to less than 0.5% sulphur are also a competing abatement option. Moreover, we analyse the interaction between global SOX reductions and CO2 (and fuel consumption), and the results indicate that the higher fuel cost for distillates will motivate shippers to lower speeds, which will offset the increased CO2 emissions at the refineries. Scrubbers, in contrast, will raise speeds and CO2 emissions.
The spatiotemporal variation, chemical fingerprints, transportation routes, and source apportionment of atmospheric fine particles (PM2.5) along the coastal region of southern Taiwan were investigated at three environments in the tip of southern Taiwan. Three representative sampling sites at Chien-Chin (urban site), Siao-Gang (industrial site) and Che-Cheng (background site) were selected for simultaneous PM2.5 sampling from December 2014 to May 2015. Regular sampling of 24-h PM2.5 was conducted for continuous 6-9 days in each month. After sampling, the chemical composition, including water-soluble ions, metallic elements and the carbonaceous content of PM2.5, was further analyzed within two weeks. The levoglucosan concentration was further compared to OC and K⁺ in PM2.5 originating from biomass burning. Moreover, the potential sources of PM2.5 and their respective contribution were further resolved by backward trajectory simulation, combined with chemical mass balance (CMB) receptor modeling. The field sampling results indicated that the PM2.5concentrations at the urban and industrial sites were always higher than those at the background site. The most abundant water-soluble ionic species of PM2.5 are SO4²⁻, NO3⁻ and NH4⁺, implying that PM2.5 is mainly composed of secondary ammonium sulfate and ammonium nitrate. The most abundant metallic elements of PM2.5 included crustal elements (Al, Fe and Ca) and anthropogenic (generated by humans) elements (V, Ni, As, Cd, Zn and Pb). Moreover, the concentrations of OC and EC at the Chien-Chin and Siao-Gang sites were generally higher than those at the Che-Cheng site, mainly due to the emissions from urban and industrial anthropogenic sources. Vehicular exhausts and industrial emissions were the main sources of PM2.5 at the Chien-Chin and Siao-Gang sites, respectively, while biomass burning and soil dusts were the dominant sources of PM2.5 at the Che-Cheng site.
As a result of the changes that occur during their use, oil from many machinery products tend to differ in term of physical and chemical composition from virgin oil. The analysis of additive, wear and contaminants element is oil will aid to understand the possible processes that alter the oil compositions. This study examine the heavy metal distribution in virgin, used, waste and recovered oil in term of their additives, contaminants and wear elements using simultaneous analysis of ICP-OES for 23 elements based on ASTM D5185 method. The results demonstrate that there is no significant change for additive element in virgin and used similar virgin oil samples. The metals for contaminants and wear elements in used, waste and recovered oil show indistinct distribution suggest that the oil lubricating, introduction of contamination foreign substances and recovery process play a role in discriminating the oil samples.
This paper reports the chemical composition of exhaust emissions from the main engines of five ocean going cargo vessels, as they travelled in Canadian waters. The emission factors (EFs) of PM2.5 and SO2 for vessels tested on various intermediate fuel oils (IFO), ranged from 0.4 to 2.2 g kW-1 hr-1 and 4.7 to 10.3 g kW-1 hr-1, respectively, and were mainly dependent on the content of sulphur in the fuel. Average NOx, CO and CO2 EFs for these tests were 12.7, 0.45 and 618 g kW-1 hr-1, respectively and were generally below benchmark values commonly used by regulatory agencies. The composition of PM2.5 was dominated by hydrated sulphates, organic carbon and trace metals which accounted for 80 to 97% of total PM2.5 mass. A substantial decrease of measured emission factors for PM2.5 and SO2 was observed when the fuel was changed from IFO to marine diesel oil (MDO), in one of the tested vessels. The main component of PM2.5 in this case was organic carbon accounting for 65% of PM2.5 mass. In addition to commonly reported pollutants, this study presents EFs of the lanthanoid elements and showed that their distribution patterns in ship-exhaust PM2.5 were very similar to the PM2.5 emitted by oil refining facilities. Hence, using La:Ce:V tertiary diagrams and La/V ratios is necessary to distinguish ship plumes from primary emissions related to accidental and/or routine operation of oil-refining industry.
In this study, positive-mode laser desorption-ionisation ultra-high-resolution mass spectrometry (LDI-FT-ICR-MS) was applied to study combustion aerosol samples obtained from a ship diesel engine as well as the feed fuel, used to operate the engine. Furthermore, particulate matter was sampled from the exhaust tube using an impactor and analysed directly from the impaction foil without sample treatment. From the high percentage of shared sum formula as well as similarities in the chemical spread of aerosol and heavy fuel oil, results indicate that the primary aerosol mainly consists of survived, unburned species from the feed fuel. The effect of pyrosynthesis could be observed and was slightly more pronounced for the CH-class compared to other compound classes, but in summary not dominant. Alkylation pattern as well as the aromaticity distribution, using the double bond equivalent, revealed a shift towards lower alkylation state for the aerosol. The alkylation pattern of the most dominant series revealed a higher correlation between different aerosol samples than between aerosol and feed samples. This was confirmed by cluster analysis. Overall, this study shows that LDI-FT-ICR-MS can be successfully applied for the analysis of combustion aerosol at the molecular level and that sum formula information can be used to identify chemical differences between aerosol and fuel as well as between different size fractions of the particulate matter.
Particle emissions from a marine diesel engine operating at low loads with four different fuels were characterized with respect to particle number (PN) and particle mass (PM), size distribution, volatility and chemical composition. The four different fuels used were Swedish Environmental class 1 (MK1) and class 3 diesel (MK3), heavy fuel oil (HFO, 0.12 wt% S) and marine diesel oil (MDO, 0.52 wt% S). The measurements were performed for a marine diesel engine in a test-bed engine lab and the particle emissions were measured with an Engine Exhaust Particle Sizer and a Dust Monitor, giving the number concentrations in the size range of 5.6–560 nm and 300 nm to 20 μm, respectively. To quantify the amount of solid particles a thermodenuder was used. Additionally, filter samples were taken for gravimetric, black carbon (BC) and elemental analysis. The particle emissions showed a bimodal size distribution by number and the number concentrations were dominated by nanoparticles (diameter (Dp) < 50 nm). The nanoparticles measured were both primary and secondary particles, depending on fuel and engine load, while the particles with Dp > 50 nm generally were solid primary particles. Combustion of HFO resulted in the highest PN and PM concentrations. Emission factors (EFs) for PM and PN for both the total particle emissions and the fraction of primary, solid particles are presented for different fuels and loads. EFs for nitrogen oxides (NOx), BC and some elements (Ca, Fe, V, Ni, Zn) are presented as well. This study contributes to understanding particle emissions from potential future fuels as well as emissions in ports and coastal areas where lower engine loads are common.
Currently, there is a limited understanding of the sources of ambient fine particles that contribute to the exposure of children at urban schools. Since the size and chemical composition of airborne particle are key parameters for determining the source as well as toxicity, PM1 particles (mass concentration of particles with an aerodynamic diameter less than 1 µm) were collected at 24 urban schools in Brisbane, Australia and their elemental composition determined. Based on the elemental composition four main sources were identified; secondary sulphates, biomass burning, vehicle and industrial emissions. The largest contributing source was industrial emissions and this was considered as the main source of trace elements in the PM1 that children were exposed to at school. PM1 concentrations at the schools were compared to the elemental composition of the PM2.5 particles (mass concentration of particles with an aerodynamic diameter less than 2.5 µm) from a previous study conducted at a suburban and roadside site in Brisbane. This comparison revealed that the more toxic heavy metals (V, Cr, Ni, Cu, Zn and Pb), mostly from vehicle and industrial emissions, were predominantly in the PM1 fraction. Thus, the results from this study points to PM1 as a potentially better particle size fraction for investigating the health effects of airborne particles.
In this study, samples of particulate matter with aerodynamic diameter less than 2.5 mu m (PM2.5) collected at two sites in the south-east Queensland region, a suburban (Rocklea) and a roadside site (South Brisbane), were analysed for H, Na, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Br, Pb and black carbon (BC). Samples were collected during 2007-10 at the Rocklea site and 2009-10 at the South Brisbane site. The receptor model Positive Matrix Factorisation was used to analyse the samples. The sources identified included secondary sulfate, motor vehicles, soil, sea salt and biomass burning. Conditional probability function analysis was used to determine the most likely directions of the sources. Future air quality control strategies may focus on the particular sources identified in the analysis.
Shipping emissions are currently increasing and will most likely continue to do so in the future due to the increase of global-scale trade. Ship emissions have the potential to contribute to air quality degradation in coastal areas, in addition to contributing to global air pollution. With the aim to quantify the impacts of shipping emissions on urban air quality in coastal areas in Europe, an in depth literature review was carried out focussing on particulate matter and gaseous pollutants but also reviewing the main chemical tracers of shipping emissions, the particle size distribution of ship-derived particulates and their contributions to population exposure and atmospheric deposition. Mitigation strategies were also addressed. In European coastal areas, shipping emissions contribute with 1-7% of ambient air PM10 levels, 1-14% of PM2.5, and at least 11% of PM1. Contributions from shipping to ambient NO2 levels range between 7 and 24%, with the highest values being recorded in the Netherlands and Denmark. Impacts from shipping emissions on SO2 concentrations were reported for Sweden and Spain. Shipping emissions impact not only the levels and composition of particulate and gaseous pollutants, but may also enhance new particle formation processes in urban areas. (C) 2014 The Authors. Published by Elsevier Ltd.
Emissions of particulate matter (PM) from shipping contribute
significantly to the anthropogenic burden of PM. The environmental
effects of PM from shipping include negative impact on human health
through increased concentrations of particles in many coastal areas and
harbour cities and the climate impact. The PM emitted by ship engines
consists of organic carbon (OC), elemental or black carbon (EC/BC),
sulphate, inorganic compounds containing V, Ni, Ca, Zn and other metals
and associated water. The chemical composition and physical properties
of PM vary with type of fuel burned, type of engine and engine operation
mode. While primary PM emissions of species like V, Ni and Ca are
supposed to be determined by composition of fuel and lubricant oil,
emissions of particulate OC, EC and sulphate are affected both by fuel
quality and by operation mode of the engine. In this paper
a number of parameters describing emission factors (EFs) of gases and of
particulate matter from ship engines were investigated during 2 on-board
measurement campaigns for 3 different engines and 3 different types of
fuels. The measured EFs for PM mass were in the range 0.3 to 2.7
g/kg-fuel with lowest values for emissions from combustion of marine gas
oil (MGO) and the highest for heavy fuel oil (HFO). Emission factors for
particle numbers EF(PN) in the range 5 × 1015-1 ×
1017 #/kg-fuel were found, the number concentration was
dominated by particles in the ultrafine mode and ca. 2/3 of particles
were non-volatile. The PM mass was dominated by particles in
accumulation mode. Main metal elements in case of HFO
exhaust PM were V, Ni, Fe, Ca and Zn, in case of MGO Ca, Zn and P. V and
Ni were typical tracers of HFO while Ca, Zn and P are tracers of the
lubricant oil. EC makes up 10-38% of the PM mass, there were not found
large differences between HFO and MGO fuels. EC and ash elements make up
23-40% of the PM mass. Organic matter makes up 25-60% of the PM. The
measured EF(OC) were 0.59 ± 0.15 g/kg-fuel for HFO and 0.22
± 0.01 g/kg-fuel for MGO. The measured
EF(SO42-) were low, ca. 100-200 mg/kg-fuel for HFO
with 1% fuel sulphur content (FSC), 70-85 mg/kg-fuel for HFO with 0.5%
FSC and 3-6 mg/kg-fuel for MGO. This corresponds to 0.2-0.7% and
0.01-0.02% of fuel S converted to PM sulphate for HFO and MGO,
respectively. The (scanning) transmission electron
microscopy (TEM and STEM) images of the collected PM have shown three
different types of particles: (1) soot composed mainly of C, O,
sometimes N, and with traces of Si, S, V, Ca and Ni; (2) char and
char-mineral particles composed of C, O, Ca and S (sometimes Si and Al)
with traces of V and Ni and sometimes P and (3) amorphous, probably
organic particles containing sulphur and some vanadium. The maps of
elements obtained from STEM showed heterogeneous composition of primary
soot particles with respect to the trace metals and sulphur. Composition
of the char-mineral particles indicates that species like
CaSO4, CaO and/or CaCO3, SiO2 and/or
Al2SiO5, V2O5 and
Fe3O4 may be present; the last two were also
confirmed by analyses of FTIR spectra of the PM samples.
The TPO of PM from the ship exhaust samples showed higher soot oxidation
reactivity compared to automotive diesel soot, PM from the HFO exhaust
is more reactive than PM from the MGO exhaust. This higher oxidation
reactivity could be explained by high content of catalytically active
contaminants; in particular in the HFO exhaust PM for which the
energy-dispersive X-ray spectroscopy (EDXRF) analyses showed high
content of V, Ni and S. Oxidative potential measured as a
rate of consumption of consumption of Dithiothreitol (DTT) was for the
first time measured on PM from ship exhaust. The obtained values were
between 0.01 and 0.04 nmol-DTT/min/μg-PM, quite similar to oxidative
potentials of PM collected in urban and traffic sites. The
data obtained during the experiments add information on emission factors
for both gaseous and PM-bound compounds from ship engines using
different fuels and under different engine load conditions. Observed
variability of the EFs illustrates uncertainties of these emission
factors as a result of measurement uncertainties, influences from trace
components of fuels and lubricants and from differences between
individual engines.
Biodiesel is an alternative, environment-friendly, and renewable fuel type for diesel engines; and its importance is increasing with each passing day. Many studies have been conducted on biodiesel and it has been suggested to be used in the engine directly. Two engines with the same characteristics have been used in this study. The respective engine wear rates are compared by running one of the engines with 100% biodiesel (B100) fuel and the other with petroleum diesel under the same operating conditions. The wear rates are determined by being analyzed in an inductively coupled plasma spectrometer. At the end of the research, it was seen that biodiesel reduced the wear for some engine parts and increased wear for some others due to oil acids and oxidation.
1] Marine vessel inventories demonstrate that ship emissions cannot be neglected in assessing environmental impacts of air pollution, although significant uncertainty in these inventories remains. We address this uncertainty by employing a bottom-up estimate of fuel consumption and vessel activity for internationally registered fleets, including cargo vessels, other commercial vessels, and military vessels. We identify model bias in previous work, which assumed internationally registered ships primarily consume international marine fuels. Updated results suggest fuel consumption is $289 million metric tons per year, more than twice the quantity reported as international fuel. According to our analysis, fuel used by internationally registered fleets is apparently allocated to both international and domestic fuel statistics; this implies either that ships operate along domestic routes much of the time or that marine fuel sales to these ships may be misassigned. If the former is true, then allocation of emissions to international shipping routes may underestimate near-coastal emissions from ships. Our updated inventories increases previous ship emissions inventories for all pollutants; for example, global NO x emissions ($6.87 Tg N) are more than doubled. This work also produces detailed sensitivity analyses of inputs to these estimates, identifying uncertainty in vessel duty-cycle as critical to overall emissions estimates. We discuss implications for assessing ship emissions impacts.
The effect of sulfur content on diesel particulate matter (DPM) emissions was studied using a diesel generator (Generac Model SD080, rated at 80 kW) as the emission source to simulate nonroad diesel emissions. A load sim-ulator was used to apply loads to the generator at 0, 25, 50, and 75 kW, respectively. Three diesel fuels containing 500, 2100, and 3700 ppm sulfur by weight were selected as generator fuels. The U.S. Environmental Protection Agency sampling Method 5 "Determination of Particulate Matter Emissions from Stationary Sources" together with Method 1A "Sample and Velocity Traverses for Stationary Sources with Small Stacks or Ducts" was adopted as a reference method for measurement of the exhaust gas flow rate and DPM mass concentration. The effects of various parameters on DPM concentration have been studied, such as fuel sulfur contents, engine loads, and fuel usage rates. The increase of average DPM concentra-tions from 3.9 mg/Nm 3 (n cubic meter) at 0 kW to 36.8 mg/Nm 3 at 75 kW is strongly correlated with the increase of applied loads and sulfur content in the diesel fuel, whereas the fuel consumption rates are only a function of applied loads. An empirical correlation for estimating DPM concentration is obtained when fuel sulfur content and engine loads are known for these types of generators: Y Z m (X), where Y is the DPM concentration, mg/m 3 , Z is the fuel sulfur content, ppm w (limited to 500-3700 ppm w), X is the applied load, kW, m is the constant, 0.407, and are the numerical coefficients, 0.0118 0.0028 (95% confidence interval) and 0.4535 0.1288 (95% confidence interval), respectively.
Composition of exhaust from a ship diesel engine using heavy fuel oil (HFO) was investigated onboard a large cargo vessel. The emitted particulate matter (PM) properties related to environmental and health impacts were investigated along with composition of the gas-phase emissions. Mass, size distribution, chemical composition and microphysical structure of the PM were investigated. The emission factor for PM was 5.3 g (kg fuel)−1. The mass size distribution showed a bimodal shape with two maxima: one in the accumulation mode with mean particle diameter DP around 0.5 μm and one in the coarse mode at DP around 7 μm. The PM composition was dominated by organic carbon (OC), ash and sulphate while the elemental carbon (EC) composed only a few percent of the total PM. Increase of the PM in exhaust upon cooling was associated with increase of OC and sulphate. Laser analysis of the adsorbed phase in the cooled exhaust showed presence of a rich mixture of polycyclic aromatic hydrocarbon (PAH) species with molecular mass 178–300 amu while PM collected in the hot exhaust showed only four PAH masses.Microstructure and elemental analysis of ship combustion residuals indicate three distinct morphological structures with different chemical composition: soot aggregates, significantly metal polluted; char particles, clean or containing minerals; mineral and/or ash particles. Additionally, organic carbon particles of unburned fuel or/and lubricating oil origin were observed. Hazardous constituents from the combustion of heavy fuel oil such as transitional and alkali earth metals (V, Ni, Ca, Fe) were observed in the PM samples.Measurements of gaseous composition in the exhaust of this particular ship showed emission factors that are on the low side of the interval of global emission factors published in literature for NOx, hydrocarbons (HC) and CO.
Particle size measurements were performed on the exhaust of a car operating on a chassis dynamometer fueled with standard gasoline and gasoline containing low levels of Pb, Fe, and Mn organometallic additives. When additives were present there was a distinct nucleation mode consisting primarily of sub-10 nm nanoparticles. At equal molar dosing Mn and Fe gave similar nanoparticle concentrations at the tailpipe, whereas Pb gave a considerably lower concentration. A catalytic stripper was used to remove the organic component of these particles and revealed that they were mainly solid and, because of their association with inorganic additives, presumably inorganic. Solid nucleation mode nanoparticles of similar size and concentration to those observed here from a gasoline engine with Mn and Fe additives have also been observed from modern heavy-duty diesel engines without aftertreatment at idle, but these solid particles are a small fraction of the primarily volatile nucleation mode particles emitted. The solid nucleation mode particles emitted by the diesel engines are likely derived from metal compounds in the lubrication oil, although carbonaceous particles cannot be ruled out. Significantly, most of these solid nanoparticles emitted by both engine types fall below the 23 nm cutoff of the PMP number regulation.
The effect of sulfur content on diesel particulate matter (DPM) emissions was studied using a diesel generator (Generac Model SD080, rated at 80 kW) as the emission source to simulate nonroad diesel emissions. A load simulator was used to apply loads to the generator at 0, 25, 50, and 75 kW, respectively. Three diesel fuels containing 500, 2100, and 3700 ppm sulfur by weight were selected as generator fuels. The U.S. Environmental Protection Agency sampling Method 5 "Determination of Particulate Matter Emissions from Stationary Sources" together with Method 1A "Sample and Velocity Traverses for Stationary Sources with Small Stacks or Ducts" was adopted as a reference method for measurement of the exhaust gas flow rate and DPM mass concentration. The effects of various parameters on DPM concentration have been studied, such as fuel sulfur contents, engine loads, and fuel usage rates. The increase of average DPM concentrations from 3.9 mg/Nm3 (n cubic meter) at 0 kW to 36.8 mg/Nm3 at 75 kW is strongly correlated with the increase of applied loads and sulfur content in the diesel fuel, whereas the fuel consumption rates are only a function of applied loads. An empirical correlation for estimating DPM concentration is obtained when fuel sulfur content and engine loads are known for these types of generators: Y = Zm(alphaX + beta), where Y is the DPM concentration, mg/m3, Z is the fuel sulfur content, ppm(w) (limited to 500-3700 ppm(w)), X is the applied load, kW, m is the constant, 0.407, alpha and beta are the numerical coefficients, 0.0118 +/- 0.0028 (95% confidence interval) and 0.4535 +/- 0.1288 (95% confidence interval), respectively.
Epidemiological studies consistently link ambient concentrations of particulate matter (PM) to negative health impacts, including asthma, heart attacks, hospital admissions, and premature mortality. We model ambient PM concentrations from oceangoing ships using two geospatial emissions inventories and two global aerosol models. We estimate global and regional mortalities by applying ambient PM increases due to ships to cardiopulmonary and lung cancer concentration-risk functions and population models. Our results indicate that shipping-related PM emissions are responsible for approximately 60,000 cardiopulmonary and lung cancer deaths annually, with most deaths occurring near coastlines in Europe, East Asia, and South Asia. Under current regulation and with the expected growth in shipping activity, we estimate that annual mortalities could increase by 40% by 2012.
This study presents an overview of the context and global impacts of recent International Maritime Organization (IMO) regulations on the marine fuel oil refining industry, future marine fuel mix and ship emissions. IMO limited marine fuel sulphur content in both Sulphur Emission Control Areas (SECAs) and Nitrogen Oxide Emission Control Areas (NECAs) to 0.1% (wt. %) by 2015, and to 0.5% globally by 2020. It is anticipated that the newly implemented IMO regulations will help to mitigate negative impact of ship emissions on public health and environment. IMO regulations require significant changes to refineries to increase the production of low sulphur fuels through a shift to distillates, use of novel deep desulphurization techniques, or fuel blending. Changes to the refinery processes can bring forth increases in greenhouse gas emissions and high capital investments. Alternative fuels will need to meet the required reduction of air pollutants and greenhouse gas emissions in coastal areas. Alternative marine fuels consisting of liquefied nature gas (LNG) and biofuel may be suitable fuels to meet both targets. These two fuels are predicted to account for 50% of shipping energy demand by 2050, while the remainder will still be supplied by conventional heavy fuel oil (HFO)/marine gas oil (MGO). Switching to low sulphur fuels as a results of the new IMO regulations has led to measureable reductions in ship emissions generally. This fuel switching also resulted in changes in engine emission characteristics, especially on particulate matter chemical composition.
Airborne particles, specifically nanoparticles, are identified health hazards and a key research domain in air pollution and climate change. We performed a systematic airport study to characterize real-time size and number density distribution, chemical composition and morphology of the aerosols (∼10 nm–10 μm) using complementary cutting-edge and novel techniques, namely optical aerosol analyzers, triple quad ICP-MS/MS and high-resolution STEM imaging. The total number density of aerosols, predominantly composed of nanoparticles, reached a maximum of 2 × 10⁶ cm⁻³ and is higher than reported values from any other international airport. We also provide evidence for a wide range of metal in aerosols, and emerging metals in nanoparticles (e.g., Zn and Ni). The geometric mean, median and 99th and 1st percentile values of observed nanoparticle number densities at the apron were 1.0 × 10⁵, 9.0 × 10⁴, 1.2 × 10⁶ and 9.3 × 10³ cm⁻³, respectively. These observations were statistically higher than corresponding measurements in downtown Montreal and at major highways during rush hour. This airport is thus a hotspot for nanoparticles containing emerging contaminants. The diurnal trends in concentrations exhibit peaks during flight and rush hours, showing correlations with pollutants such as CO. The HR-TEM-EDS provided evidence for nano-sized particles produced in combustion engines. Implications of our results for air pollution and health are discussed.
Little is known regarding the oxidative potential of biodiesel particulate matter (PM) relative to diesel PM emitted from heavy duty diesel (HDD) nonroad engines generated in real-world occupational settings. The composition of biodiesel and diesel PM can include transition metals, polar, and nonpolar organic species which can increase oxidative potential via production of reactive oxygen species (ROS). Elevated ROS can lead to oxidative stress and induce antioxidant defense, inflammation, and toxicity. This study characterized the chemical composition of PM (water soluble organic carbon and elemental metals) collected in a real-world occupational setting. ROS production in a human epithelial cell line (BEAS-2B) treated with biodiesel and diesel PM extracts was compared to oxidative potential measured by an acellular dithiothreitol (DTT) assay. The oxidative potential (DTT consumption rate) of diesel PM was 21% greater than biodiesel PM at the highest treatment concentration (60 μg/mL), yet the ROS generated in vitro were similar between fuel types. Average concentrations of Cu, Cr and Zn were higher in diesel PM compared to biodiesel PM. Additionally, there was a significant correlation between DTT consumption and Cu in diesel PM (r = 0.98), but not B20 PM. There was a strong correlation between WSOC content in diesel PM and ROS generated in vitro (r = 0.83), but no correlation between WSOC content in biodiesel PM and ROS. Taken together, the results indicate the influence of fuel type on the chemical composition and oxidative potential of PM generated by a nonroad HDD engine operated at a recycling center. While acknowledging the potential influence of other species of interest not measured (i.e., quinones), real-world petroleum diesel PM emissions had higher oxidative potential compared to biodiesel PM suggesting that biodiesel use may reduce risk to human health.
Particle emission characteristics and engine performance were investigated from an auxiliary, heavy duty, six-cylinder, turbocharged and after-cooled diesel engine with a common rail injection system using spiked fuels with different combinations of sulphur (S) and vanadium (V) spiking. The effect of fuel S content on both particle number (PN) and mass (PM) was clearly observed in this study. Higher PN and PM were observed for fuels with higher S contents at all engine load conditions. This study also found a correlation between fuel S content and nucleation mode particle number concentration which have more harmful impact on human health than larger particles. The highest PN and PM were observed at partial load conditions. In addition, S in fuel resulted in higher viscosity of spiked fuels, which led to lower engine blow-by. Fuel V content was observed in this study, evidencing that it had no clear effect on engine performance and emissions. Increased engine load also resulted in higher engine blow-by. The lower peak of in-cylinder pressure observed at both pre-mixed and diffusion combustion phases with the spiked fuels may be associated with the lower energy content in the fuel blends compared to diesel fuel.
This study investigated particle and gaseous emission factors from a large cargo vessel for her whole voyage including at berth, manoeuvring and cruising. Quantification of these factors assists in minimising the uncertainty in the current methods of exhaust gas emission factor estimation. Engine performance and emissions from the main marine engine were measured on-board while the ship was manoeuvring and cruising at sea. Emissions of an auxiliary engine working at 55% of maximum continuous rating (MCR) were measured when the ship was at actual harbour stopovers. Gaseous and particle emission factors in this study are presented in g kWh(-1) or # kWh(-1), and compared with previous studies. Results showed that the SO2 emission factor is higher than that of previous studies due to the high sulphur content of the fuel used. The particle number size distributions showed only one mode for different operating conditions of the ship, with a peak at around 40-50 nm, which was dominated by ultrafine particles. Emission factors of CO, HC, PM and PN observed during ship manoeuvring were much higher than that of those recorded at cruising condition. These findings highlight the importance of quantification and monitoring ship emissions in close proximity to port areas, as they can have the highest impact on population exposure.
T{(NPI), 1999 #117}his research compares the effects of oxygenated fuels on engine blow-by during engine cold and hot start operation using a common rail, turbocharged diesel engine. Diesel, waste cooking biodiesel and a highly oxygenated additive, triacetin, were used to make a range of fuel oxygen contents (0–13.57%). This study investigated engine blow-by and its correlation with indicated, brake and friction power; and blow-by normalised by different parameters. Result showed that neat diesel produces higher blow-by during cold start than the oxygenated fuels. There was a strong correlation between blow-by and indicated power, and the fuel calorific value was identified as a leading factor. To further analyse the results, this study normalised the engine blow-by by power to reveal the other influences on engine blow-by. The result verified the strong influence of power. This study also furthered the analysis by normalising the blow-by data by exhaust flow rate, intake air flow rate and injected fuel flow rate. It was discovered that oxygenated fuels perform better between hot and cold start, when compared to diesel. The blow-by inhibited properties of oxygenated fuels, such as higher lubricity and viscosity may be the cause for better performance of oxygenated fuels during cold start.
This study systematically examined the potential impacts of doping CeO2 and Fe(C5H5)2 nanoparticles as fuel-borne catalysts (FBCs) to ultralow sulfur diesel (ULSD) fuel on the physical, chemical and toxicological characteristics of diesel particulate matter (DPM). The FBCs-doped fuels are effective in promoting soot oxidation and reducing the DPM mass emissions, but lead to a significant increase in the total particle counts due to the formation of self-nucleated metallic nanoparticles. Compared to undoped ULSD, the FBCs-doped fuels result in higher concentrations of particle-phase polycyclic aromatic hydrocarbons (PAHs) and n-alkanes, higher fractions of organic carbon (OC) and water-soluble organic carbon (WSOC) in particles, show slight alterations in soot nanostructure, reduce soot ignition temperature and activation energy. Exposure of the human-type II cell alveolar epithelial cells (A549) to DPM derived from FBCs-doped fuels shows a decrease in cell viability and alterations in the global gene expression with a broad range of biochemical pathways. The overall variations in DPM characteristics are mainly caused by the catalytic combustion process, and are related to the type, properties and contents of FBCs used in diesel fuel as well as the engine operating conditions. Environmental and health implications of the study are highlighted.
A proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS) combined with the novel CHARON (“chemical analysis of aerosol online”) aerosol inlet was used for characterization of submicron particulate organic matter in ship engine exhaust. Particles were sampled from diluted and cooled exhaust of a marine test bench engine that was operated on residual Heavy Fuel Oil (HFO) and low-sulfur distillate Marine Gas Oil (MGO), respectively. In both fuel operation modes, exhaust particle mass spectra were dominated by polycycloalkanes in the C20-to-C39 range, which are typical main constituents of lubricating oils. Exhaust particle mass spectra were closely reproduced when the engine’s lubricant oil was directly measured in aerosolized form. We report emission profiles of lubricant oil hydrocarbons as a function of their volatility and as a function of their carbon atom number. Total emissions of lubricant oil amounted to 183 mg kW⁻¹h⁻¹ and 74 mg kW⁻¹h⁻¹ for HFO and MGO combustion, respectively. These values resemble typical oil loss rates of marine four-stroke trunk piston engines in which most of the lubricant is known to be lost through the combustion chamber and the tailpipe. We conclude that marine trunk piston engines are generally prone to high emissions of particles mainly composed of unburned lubricating oil.
Heavy fuel oil (HFO) is primarily used as fuel in marine engines and boilers to generate electricity. Nuclear magnetic resonance (NMR) is a powerful analytical tool for structure elucidation, and in this study, 1H and 13C NMR spectroscopy were used for the structural characterization of two HFO samples. The NMR data were combined with elemental analysis and average molecular weight to quantify average molecular parameters (AMPs), such as the number of paraffinic carbon, naphthenic carbon, aromatic hydrogen, olefinic hydrogen, etc., in the HFO samples. Recent formulas published in the literature were used for calculating various derived AMPs, such as aromaticity factor (fa), C/H ratio, average paraffinic chain length (n), naphthenic ring number (RN), aromatic ring number (RA), total ring number (RT), aromatic condensation index (ρ), and aromatic condensation degree (ω). These derived AMPs help in understanding the overall structure of the fuel. A total of 19 functional groups were defined to represent the HFO samples, and their respective concentrations were calculated by formulating balance equations that equate the concentration of the functional groups with the concentration of the AMPs. Heteroatoms, such as sulfur, nitrogen, and oxygen, were also included in the functional groups. Surrogate molecules were finally constructed to represent the average structure of the molecules present in the HFO samples. This surrogate molecule can be used for property estimation of the HFO samples and also serves as a surrogate to represent the molecular structure for use in kinetic studies.
Due to current and upcoming regulations to address the adverse impacts of particulate matter (PM) from shipping emissions, the maritime sector is required to find energy-efficient ways to comply mainly by using low fuel sulfur content (FSC) in regulated seas. We studied the PM emission from a research ship diesel engine with fuel switching capability, optimized for HFO used at cruising, operated at representative engine loads resulting to varying excess O2 emission which was an indirect measurement of air–fuel mixture (λ), using heavy fuel oil (HFO, 1.6 S (%m)) and diesel fuel (DF, <0.001 S (%m)). We determined the characteristics and temporal evolution of the PM by using the High Resolution Time-of-Flight Aerosol Mass Spectrometry (HR-ToF-AMS) in combination with aethalometer, particle sizers, online gas phase, and filter measurements. The average emission factors were higher for HFO than for DF with relative percent differences of ∼200, ∼180, ∼150, and ∼145 for SO42−, inorganic elements, organic matter (OM), and PM2.5, respectively, while that for black carbon (BC) was similar for both fuels. The difference between HFO and DF in terms of carbonaceous emissions was higher at 100% and 25% than at 75% and 50% engine loads. The exhaust temperature (T) decreased with increasing λ leading to the enhanced emission of OM in HFO and reduced OM and BC emission in DF. Contributions of hydrocarbons and oxygenated hydrocarbons increased with λ for HFO and decreased with DF. Gas phase total hydrocarbon (THC) was well correlated with BC only for HFO and OM and BC for DF. Overall, using a lower FSC reduced average PM emissions, however, engine load, and λ were strongly linked to the characteristics and temporal evolution of major PM emissions. The information in this study may help the marine sector and policy-making process in evaluating and designing future solutions for shipping emission regulations and diagnostics.
The approaching marine fuel sulphur regulations will result in reductions in emissions of sulphur oxides to air. Importantly, also particle emissions that impose health risks will be lessened by these regulations. Combustion particles from marine engines are complex mixtures of organic compounds, soot, sulphate, metals and other inorganic species. Their composition and abundance are determined both by fuel and engine characteristics. Health risks from particles are thought to be related to the size of particles and chemical composition of particles which makes particle mass a coarse parameter for indication of how harmful emissions are. This article presents emission measurements conducted on board two ships with a focus on comparing number concentrations of ultrafine particles (Dp<100 nm) in diluted exhaust for three different fuel qualities. The fuels are chosen based on their relevance to existing and coming into force regulations on sulphur in fuel. Implications of these regulations for Sulphur Emission Control Areas on health risks from a shift from heavy fuel oils to low-sulphur marine gas oil are discussed with the measurement results as a basis. The results from the presented measurement emphasise the effect of fuel type on particle formation. The strong relation between sulphur content of fuel and particle emissions is obvious for particle mass but not for particle number and particle sizes.
Particle emissions from a modern turbocharged GDI passenger car equipped with a three-way catalyst and an exhaust gas recirculation system were studied while the vehicle was running on low-sulfur gasoline and, consecutively, with five different lubrication oils. Exhaust particle number concentration, size distribution and volatility were determined both at laboratory and on-road conditions. The results indicated that the choice of lubricant affected particle emissions both during the cold start and warm driving cycles. However, the contribution of engine oil depended on driving conditions being higher during acceleration and steady state driving than during deceleration. The highest emission factors were found with two oils that had the highest metal content. The results indicate that a 10 % decrease in the Zn content of engine oils is linked with an 11-13% decrease to the non-volatile particle number emissions in steady driving conditions and a 5 % decrease over the New European Driving Cycle (NEDC). The effect of lubricant on volatile particles was even higher, in the order of 20%.
The chemical composition of particulate matter (PM) emissions from a medium-speed four-stroke marine engine, operated on both heavy fuel oil (HFO) and distillate fuel (DF), was studied under various operating conditions. PM emission factors for organic matter, elemental carbon (soot), inorganic species and a variety of organic compounds were determined. In addition, the molecular composition of aromatic organic matter was analyzed using a novel coupling of a thermal-optical carbon analyzer with a resonance-enhanced multiphoton ionization (REMPI) mass spectrometer. The polycyclic aromatic hydrocarbons (PAHs) were predominantly present in an alkylated form, and the composition of the aromatic organic matter in emissions clearly resembled that of fuel. The emissions of species known to be hazardous to health (PAH, Oxy-PAH, N-PAH, transition metals) were significantly higher from HFO than from DF operation, at all engine loads. In contrast, DF usage generated higher elemental carbon emissions than HFO at typical load points (50% and 75%) for marine operation. Thus, according to this study, the sulfur emission regulations that force the usage of low-sulfur distillate fuels will also substantially decrease the emissions of currently unregulated hazardous species. However, the emissions of soot may even increase if the fuel injection system is optimized for HFO operation.
Ocean-going ships burn heavy fuel oil. The combustion of heavy fuel oil in marine diesel engines emits nitrogen oxides, sulfur oxides, and particulates into the air. Growing public concern over air quality has led to increased scrutiny of heavy fuel oil as a source of air pollutants, with calls for greater regulation of its composition to safeguard public health and the environment. Heavy fuel oil is a complex mixture, prepared by blending residual oil from petroleum distillation with more volatile fractions to meet industry standards. The fuel composition has a significant effect on the type and amount of combustion products produced, but the complexity of heavy fuel oil blends has hindered past efforts at analysis. The advanced distillation curve (ADC) method was developed as a complex fluid analysis protocol, combining thermophysical and chemical properties measurement. We applied the ADC method, under reduced pressure, to a sample of IFO 380 intermediate fuel oil to characterize its volatility and composition as a function of volume fraction. Applying the analytical method to heavy fuel oil yields quantitative data that can be used to model and design more efficient internal combustion engines for ocean-going ships, improving maritime fuel economy while reducing the amount of harmful pollutants released into the atmosphere.
Large ships, particularly container ships, tankers, bulk carriers and cruise ships are significant individual contributors to air pollution. The European Environment Agency recognizes that air pollution in Europe is a local, regional and transborder problem caused by the emission of specific pollutants, which either directly or through chemical reactions lead to negative impacts, such as damage to human health and ecosystems. In the Marine Strategy Framework Directive 2008/56/EC of the European Parliament emissions from ships are mentioned explicitly in the list of pressures and impacts that should be reduced or minimized to maintain or obtain a good ecological status. While SOx and NOx contribute mainly to ocean and soil acidification and climate change, PM (particularly ultrafine particles in the range of nanoparticles) has the potential to act more directly on human and ecosystem health. Thus, in terms of risk assessment, one of the most dangerous atmospheric aerosols for environmental and human health is in the size range of nanoparticles. To our knowledge, no study has been carried out on the effects of the fraction that ends up in the water column and to which aquatic and sediment-dwelling organisms are exposed. Therefore, it is needed to carry out an integrated environmental risk assessment of the effects of emissions from oceangoing ships. Research should focus on the quantitative and qualitative determination of pollutant emissions from ships and their distribution and fate. This will include the in situ measurement of emissions in ships in order to derive realistic emission factors, and the application of atmospheric and oceanographic transportation and chemistry models.
The upcoming stricter emission control area (ECA) regulations on sulphur and nitrogen oxides (NOX) emissions from shipping can be handled by different strategies. In this study, three alternatives complying with the ECA regulations for sulphur as well as Tier III for NOX are presented and compared using life cycle assessment. None of the three alternatives will significantly reduce the life cycle impact on climate change compared to heavy fuel oil (HFO). However, all alternatives will reduce the impact on particulate matter, photochemical ozone formation, acidification and terrestrial eutrophication potential. The assessment also highlighted two important regulatory aspects. Firstly, the need to regulate the ammonia slip from use of selective catalytic reduction (SCR) and secondly the need to regulate the methane slip from LNG engines. In addition, an analysis of the use of SCR in Swedish waters is presented showing that SCRs have been used on a number of ships already giving significantly reduced NOX emissions.
Very little is currently known about the relationship between exposure to different sources of ambient ultrafine particles (PM0.1) and human health effects. If human health effects are enhanced by PM0.1’s ability to cross cell membranes, then more information is needed describing the sources of ultrafine particles that are deposited in the human respiratory system. The current study presents results for the source apportionment of airborne particulate matter in six size fractions smaller than 1.8 μm particle diameter including ultrafine particles (PM0.1) in one of the most polluted air basins in the United States. Size-resolved source apportionment results are presented at an urban site and rural site in central California’s heavily polluted San Joaquin Valley during the winter and summer months using a molecular marker chemical mass balance (MM–CMB) method. Respiratory deposition calculations for the size-resolved source apportionment results are carried out with the Multiple Path Particle Dosimetry Model (MPPD v 2.0), including calculations for ultrafine (PM0.1) source deposition.
An eight-stage cascade impactor, with cut-sizes ranging from 0.056 to 18 μm at a flow rate of 30 L/min, has been developed, calibrated, and tested in field programs. This impactor, called a microorifice uniform deposit impactor, has several features not normally found in cascade impactors. Ultrafine particles as small as 0.056 μm are collected while keeping the pressure drop moderate by utilizing multiple nozzles (up to 2000) as small as 52 μm in diameter. At each stage the collected particles are deposited uniformly over the entire impaction plate by rotating the impaction plate relative to the nozzles and by the correct radial placement of the nozzles. The particle cutoff characteristics (collection efficiency curves) of each stage and interstage losses were determined by means of monodisperse aerosols. The cutoff characteristics were found to be sharp and similar for all stages. This is Publication No. 758 from the Particle Technology Laboratory.
Five different sulfur content fuels were used on a light-duty diesel engine to study the effect of fuel sulfur on emissions. Four regulated emissions: smoke, nitrogen oxide (NOx), unburned hydrocarbon (HC) and carbon monoxide (CO) emissions of the engine were investigated, as well as three unregulated emissions: formaldehyde (HCHO), acetaldehyde (MECHO) and sulfur dioxide (SO2). The smoke emission decreases continuously and remarkably with the fuel sulfur content, and the fuel sulfur has more influence on smoke emission at lower engine load. The concentration of NOx emissions did not change significantly with the different sulfur content fuels. As the fuel sulfur content decreases, the concentrations of HC and CO emissions have distinct reduction. The HCHO emission values are very low. The MECHO emission decreases with increasing engine load, and it continuously decreases with the fuel sulfur content and it could not be detected at higher engine load with 50ppm sulfur fuel. The SO2 emission increases continuously with the engine load, and obviously decreases with the fuel sulfur contents.
Ocean going vessels are one of the largest uncontrolled sources of pollutants and the emissions data from these sources are scarce. This paper provides the emission measurements of gases, particulate matter (PM), metals, ions, elemental and organic carbon, conducted from the main engine of an ocean going PanaMax class container vessel, at certification cycle and at vessel speed reduction mode, during actual operation at sea. The weighted emission factor (gkW−1h−1) of PM and NOx were 1.64 and 18.2, respectively, for the main engine operating on a 2.05wt% sulfur heavy fuel oil (HFO). The NOx emissions at the vessel speed reduction mode (8% of full load) are 30% higher than at 52% engine power, the normal cruise speed. The composition of PM, from main engine is dominated by sulfate and water bound with sulfate (about 80% of total PM) and organic carbon constitutes about 15% of the PM. Sulfur, vanadium and nickel are the significant elements in the exhaust from the engine running on the HFO. At the point of sampling 3.7–5.0% of the fuel sulfur was converted to sulfate.
Particulate matter (PM) emissions from one serial 4-stroke medium-speed marine diesel engine were measured for load conditions from 10% to 110% in test rig studies using heavy fuel oil (HFO). Testing the engine across its entire load range permitted the scaling of exhaust PM properties with load. Emission factors for particle number, particle mass and chemical compounds were determined. The potential of particles to form cloud droplets (cloud condensation nuclei, CCN) was calculated from chemical composition and particle size. Number emission factors are (3.43±1.26)x10^16 (kg fuel)–1 at 85-110% load, and (1.06±0.10)x10^16 (kg fuel)–1 at 10% load. CCN emission factors of 1-6 x 10^14 (kg fuel) -1 are at the lower bound of data reported in the literature. From combined thermal and optical methods, black carbon (BC) emission factors of 40 – 60 mg/(kg fuel) were determined for 85-100% load and 370 mg/(kg fuel) for 10% load. The engine load dependence of the conversion efficiency for fuel sulfur into sulfate of (1.08±0.15)% at engine idle to (3.85±0.41)% at cruise may serve as input to global emission calculations for various load conditions.
Emissions of exhaust gases and particles from oceangoing ships are a significant and growing contributor to the total emissions from the transportation sector. We present an assessment of the contribution of gaseous and particulate emissions from oceangoing shipping to anthropogenic emissions and air quality. We also assess the degradation in human health and climate change created by these emissions. Regulating ship emissions requires comprehensive knowledge of current fuel consumption and emissions, understanding of their impact on atmospheric composition and climate, and projections of potential future evolutions and mitigation options. Nearly 70% of ship emissions occur within 400 km of coastlines, causing air quality problems through the formation of ground-level ozone, sulphur emissions and particulate matter in coastal areas and harbours with heavy traffic. Furthermore, ozone and aerosol precursor emissions as well as their derivative species from ships may be transported in the atmosphere over several hundreds of kilometres, and thus contribute to air quality problems further inland, even though they are emitted at sea. In addition, ship emissions impact climate. Recent studies indicate that the cooling due to altered clouds far outweighs the warming effects from greenhouse gases such as Carbon dioxide (CO2) or ozone from shipping, overall causing a negative present-day radiative forcing (RF). Current efforts to reduce sulphur and other pollutants from shipping may modify this. However, given the short residence time of sulphate compared to CO2, the climate response from sulphate is of the order decades while that of CO2 is centuries. The climatic trade-off between positive and negative radiative forcing is still a topic of scientific research, but from what is currently known, a simple cancellation of global mean forcing components is potentially inappropriate and a more comprehensive assessment metric is required. The CO2 equivalent emissions using the Global Temperature Change Potential (GTP) metric indicate that after 50 years the net global mean effect of current emissions is close to zero through cancellation of warming by CO2 and cooling by sulphate and nitrogen oxides.
In this study the today's fleet-average emission factors of the most important ship exhausts are used to calculate emission scenarios for the future. To develop plausible future technology scenarios, first upcoming regulations and compliance with future regulations through technological improvements are discussed. We present geographically resolved emission inventory scenarios until 2050, based on a mid-term prognosis for 2020 and a long-term prognosis for 2050. The scenarios are based on some very strict assumptions on future ship traffic demands and technological improvements. The four future ship traffic demand scenarios are mainly determined by the economic growth, which follows the IPCC SRES storylines. The resulting fuel consumption is projected through extrapolations of historical trends in economic growth, total seaborne trade and number of ships, as well as the average installed power per ship. For the future technology scenarios we assume a diesel-only fleet in 2020 resulting in fuel consumption between 382 and 409 million metric tons (Mt). For 2050 one technology scenario assumes that 25% of the fuel consumed by a diesel-only fleet can be saved by applying future alternative propulsion plants, resulting in a fuel consumption that varies between 402 and 543 Mt. The other scenario is a business-as-usual scenario for a diesel-only fleet even in 2050 and gives an estimate between 536 and 725 Mt. Dependent on how rapid technology improvements for diesel engines are introduced, possible technology reduction factors are applied to the today's fleet-average emission factors of all important species to estimate future ship emissions. Combining the four traffic demand scenarios with the four technology scenarios, our results suggest emissions between 8.8 and 25.0 Tg (NO2) in 2020, and between 3.1 to 38.8 Tg (NO2) in 2050. The development of forecast scenarios for CO2, NOx, SOx, CO, hydrocarbons, and particulate matter is driven by the requirements for global model studies of the effects of these emissions on the chemical composition of the atmosphere and on climate. The developed scenarios are suitable for use as input for chemical transport models (CTMs) and coupled chemistry-climate models (CCMs).
This paper presents the contribution to population exposure (PE) of regional background fine primary (PPM2.5) and secondary inorganic (SIA) particulate matter and its impact on mortality in Europe during 1997–2003 calculated with a chemistry transport model. Contributions to concentrations and PE due to emissions from shipping, Western (WEU), Eastern (EEU), and Northern Europe are compared.WEU contributes about 40% to both PPM2.5 and SIA concentrations, whereas the EEU contribution to PPM2.5 is much higher (43% of total PPM2.5) than to SIA (29% of total SIA). The population weighted average concentration (PWC) of PPM2.5 is a factor of 2.3 higher than average (non-weighted) concentrations, whereas for SIA the PWC is only a factor 1.6 higher. This is due to PPM2.5 concentrations having larger gradients and being relatively high over densely populated areas, whereas SIA is formed outside populated areas. WEU emissions contribute relatively more than EEU to PWC and mortality due to both PPM2.5 and SIA in Europe.The number of premature deaths in Europe is estimated to 301 000 per year due to PPM2.5 exposure and 245 000 due to SIA, despite 3.3 times higher average SIA concentrations. This is due to population weighting and assumed (and uncertain) higher relative risk of mortality for PPM2.5 components (2.8 times higher RR for PPM2.5). This study indicates that it might be more efficient, for the health of the European population, to decrease primary PM emissions (especially in WEU) than to decrease precursors of SIA, but more knowledge on the toxicity of different PM constituents is needed before firm conclusions can be drawn.
Particulate matter (PM) emissions involve a complex mixture of solid and liquid particles suspended in a gas, where it is noted that PM emissions from diesel engines are a major contributor to the ambient air pollution problem. While epidemiological studies have shown a link between increased ambient PM emissions and respiratory morbidity and mortality, studies of this design are not able to identify the PM constituents responsible for driving adverse respiratory health effects. This review explores in detail the physico-chemical properties of diesel PM (DPM) and identifies the constituents of this pollution source that are responsible for the development of respiratory disease. In particular, this review shows that the DPM surface area and adsorbed organic compounds play a significant role in manifesting chemical and cellular processes that if sustained can lead to the development of adverse respiratory health effects. The mechanisms of injury involved included inflammation, innate and acquired immunity, and oxidative stress. Understanding the mechanisms of lung injury from DPM will enhance efforts to protect at-risk individuals from the harmful respiratory effects of air pollutants.
Fuel properties and emission characteristics of essential oil blends in a compression ignition engine
- Sma Rahman
- T Chu-Van
- F M Hossain
- M Jafari
- A Dowell
- M A Islam
Rahman SMA, Chu-Van T, Hossain FM, Jafari M, Dowell A, Islam MA, et al. Fuel
properties and emission characteristics of essential oil blends in a compression
ignition engine. Fuel 2019;238:440-53.
Visualization of a correlation matrix: corrplot. The Comprehensive R Archive Network
- T Wei
- V Simko
- M Levy
- Y Xie
- Y Jin
- J Zemla
Wei T, Simko V, Levy M, Xie Y, Jin Y, Zemla J. Visualization of a correlation matrix:
corrplot. The Comprehensive R Archive Network 2017.
Physical and chemical characterisation of PM emissions from two ships operating in European emission control areas
- Moldanová