Fig 3 - uploaded by Mohammad Rasul
Content may be subject to copyright.
Contexts in source publication
Context 1
... can be produced by various sources such as fossil fuels, nuclear fission, renewable sources etc. Figure 3 shows a typical schematic diagram of electricity production from burning coal. A typical pulverized coal (PC) combustion power plant is equipped with three units, boiler block, generator block and flue gas clean up block. The boiler block is the main unit where coal is burned with air to generate high pressure steam; the generator block contains the steam turbine/electric generator set, condenser and cooling water; and the third block is the flue gas clean-up unit which removes particulate matter (PM) and other pollutants from the flue gas to control emissions. This third unit carries out Selective Catalytic Reduction (SCR) for NOx (Nitrogen Oxide) removal, electrostatic precipitation (ESP) for particulate matter removal, and wet flue gas desulphurisation (FGD) or wet lime scrubbing to remove SOx and mercury. The level of emission control of this unit is 95% – 99% depending on the type of coal used (World Coal Institute, 2010). Narula illustrated that, due to the addition of CO 2 amine scrubbers at the back end of the power plant to reduce CO 2 emissions, the net plant output decreases by about 25 percent from 2 x 400 to 600 MW, and the plant heat rate increases to 13,250 kJ/kWh from 9,800 kJ/kWh, and the capital cost of the plant increases by about 77% (Narula et al ., 2002). To prevent major climate change, CO 2 concentration in the atmosphere should be reduced by either CO 2 up-take from the atmosphere biologically or reducing the CO 2 emissions from the sources. There are some approaches available for reduction of CO 2 emissions from stationary sources such as reduction of the consumption of energy generated using fossil fuels, increase in energy generation by non-fossil fuel sources such as solar, wind, biomass, and nuclear energy and using carbon capture and storage (CCS) technology for large scale production. In CCS-technologies, CO 2 is separated from the flue gas from any source and used in other processes or stored in a safe place, such as underground storage and ocean storage. In this study, only reducing/capturing CO 2 from flue gas will be considered among the three phases (capture, transport, storage) of CCS technology. The idea of separating and storing CO 2 for mitigation of its emissions to the atmosphere was first proposed in 1977 (Marchetti, 1977). Since then a lot of research work has been done on the possible mitigation options. Nowadays there are many CO 2 capture technologies available; some of these technologies are commercially established and some are under development. Mainly there are three pathways (illustrated in Figure 4) to reduce CO 2 emissions, these being post or after combustion, pre or before combustion and oxy-fuel combustion with CO 2 . In pre-combustion processes, CO 2 and other pollutants such as NOx and SOx are removed through gasification before combustion (Kreutz et al ., 2002; Williams, 2003). On the other hand, CO 2 is removed after combustion in post combustion technology. In oxy-fuel combustion, CO 2 is separated during combustion generating a flue gas stream containing mainly CO 2 and H 2 O. This technique is simple and comprises mainly compression and cooling steps and no extra solvents are required (IPCC, 2005). This technology is mainly used in glass, aluminium and steel furnaces to remove CO 2 , but in power generation it is still an emerging technology and some large scale pilot plants are planned or under way. This process removes the CO 2 from any industrial sources prior to combustion of fuel like coal, oil or gas to produce energy. In the pre-combustion process, fuel is first converted into synthesis gas containing hydrogen and carbon monoxide (CO). This CO reacts with water and produces CO 2 , and finally this CO 2 is separated from the hydrogen and compressed for transportation and storage. Then the remaining hydrogen is combusted to produce energy. About 90%-95% of CO 2 emissions can be reduced by this technology. Pre-combustion technologies are shown in Figures 5. This technology is currently used in oil refineries, but has limited use in power plants. Integrated Gasification Combined Cycle (IGCC) and Fluidized Bed Combustion (FBC) technology are involved in pre-combustion CO 2 capture. Currently, Integrated Gasification Combined-Cycle (IGCC) technology is used to produce electricity and reduce emissions from power plants. Carbon is captured using IGCC technology before combustion using low pressure with a physical solvent (e.g., Selexol and Rectisol processes), or a chemical solvent (e.g., methyl diethanolaimine (MDEA)). In this process, fossil fuel is first converted into CO 2 and Hydrogen gas (H 2 ). Then, the H 2 and the CO 2 gas are separated from each other and electricity is produced by the combustion of Hydrogen-rich gas. About 90% of the CO 2 can be removed from a power plant by pre-combustion CO 2 capture using IGCC technology, though pre-combustion technology is mainly applicable for new power plants, not being economic ...
Context 2
... can be produced by various sources such as fossil fuels, nuclear fission, renewable sources etc. Figure 3 shows a typical schematic diagram of electricity production from burning coal. A typical pulverized coal (PC) combustion power plant is equipped with three units, boiler block, generator block and flue gas clean up block. ...
Context 3
... process route with Ca/Mg-Silicates has some advantage for its direct reaction, simple process design, exothermic energy generated by the carbonation reaction that can be utilized in another process and no extra solvent is required to enhance the reaction (Lackner et al., 1995;Huijgen, 2007). Figure 13 shows the direct gas solid carbonation process flowchart. Basic chemical reaction of this process is given below, ...
Similar publications
![Figure 1.1 A typical electrical grid system set-up [1]](profile/Patrick-Akpan/publication/344518266/figure/fig1/AS:944009832833025@1602080891604/A-typical-electrical-grid-system-set-up-1_Q320.jpg)
![Figure 2.2 A typical daily load curve and load duration curve [30]](profile/Patrick-Akpan/publication/344518266/figure/fig4/AS:944009832845315@1602080891904/A-typical-daily-load-curve-and-load-duration-curve-30_Q320.jpg)
![Figure 2.4 Definition for Plant generation cycling [35]](profile/Patrick-Akpan/publication/344518266/figure/fig5/AS:944009832841217@1602080891937/Definition-for-Plant-generation-cycling-35_Q320.jpg)
Tangential fired boiler is one of the methods that can produce more complete combustion. This method applied in Suralaya Power Plant, Indonesia. However, the boiler where supposed to use low rank coal (LRC), but at a given time must be mixed with medium rank coal (MRC) from another unit because of lack of LRC coal. Accordingly to the situation, the...
This paper presents a co-firing experience, with coal and biomass, whose objective was to prove the technical, environmental and economical feasibility (although the paper does not deal with this last one) of the implantation of this technology in a power plant of pulverised low rank coal. Precisely, this kind of coal particularities, specially its...
Citations
... The use of agricultural residues as feedstock for biomass-based energy generation has been gaining popularity in many countries. Several studies have been undertaken in many parts of India, which focus on agricultural wastes such as rice straw as a possible feedstock for biomass based energy (Moazzem et al 2012, Allen et al 2020. Due to such a substantial crop production, agricultural residues could be a significant biomass-based energy source in countries like India (Popp et al 2014, Mohammed et al 2018. ...
Environmental alarms like climate change and rising air pollution levels in north India, particularly in the Delhi National Capital Region (NCR), draw attention to the severe issue of Rice straw burning. Straw burning is the common practice in Punjab and Haryana's Indo-Gangetic plains. Large-scale burning of residues (straw and stubble) is a severe problem that emits Green House Gases (GHGs) while polluting the air, posing health problems, and eliminating micronutrients from burned-out field. Residue management has been a problem for the paddy farmers and as time changes, it is necessary to update their practices. For the disposal of rice residue, farmers are constrained by an insufficient technology base and a lack of viable economic solutions. Technical solutions are available, classified mainly as on-site (in situ) and off-site (ex situ) solutions, the in situ solution includes a variety of machines that can be used to incorporate or mulch residue efficiently. While ex situ management allow collecting the residue from field for various applications such as energy production, briquetting, composting, paper and cardboard making, and for mushroom cultivation. Farmers in North India are not aware of the prolific alternatives for managing stubble and, therefore, consider burning as the best option. Therefore, extensive awareness programs are needed to inform farmers about economic options and the effects of stubble burning. Zero till drill, happy seeder and super Straw Management System (SMS) are recommended for the farmers, and need to be supplied in sufficient quantity to evade residue burning in these regions. Meanwhile, alternative technology for straw management constitutes an active area of research, area-specific and crop-specific applications need to be evolved. All stakeholders i.e., farmers, researchers, extension agents and policy makers need to be engaged in understanding and harnessing the full potential of using crop residues with conservation agriculture for sustainability and resilience of Indian agriculture.
... Reducing the use of fossil fuels and coal by increasing the use of renewable energy has been promoted globally (10)(11)(12). Carbon reduction can use carbon capture and storage (CCS) technology through various means including membranes and carbonation (13), carbon-based material recycling (14), and other methods that are compatible and mutually supportive. Abiotic control also works naturally in the air (15). ...
Black carbon aerosol is able to absorb solar radiation and the earth's surface, which results in warming of the air. In addition, aerosols that are directly absorbed through inhalation can have a negative impact on human health. Meanwhile, the ability of air to reduce the level of pollution is the deconcentrating of pollutants through abiotic mechanisms in the form of distribution, dilution, precipitation and washing when it rains. To strengthen the abiotic approach, this study aims to develop a biotic strategy by preparing plants capable of deconcentrating black carbon. The research method is based on a literature review, which specifically addresses the issue of black carbon. Literature is collected from the Mendeley platform and enriched through resource searches in open access journals. The results obtained are cleaning priorities for the closest source of aerosol generation, plant placement in priority areas, selection of plant species, intensification of vegetation quality and management of land cover extensification. The contribution of biotic strategies and phytoremediation pathways enhances the aerosol cleaning process. Plant maintenance and regeneration determine the sustainability of aerosol phytoremediation.
... Because of this, petroleum producing countries were always making global efforts to reduce the concentration of the carbon dioxide in the atmospheric foot print (Leung et al, 2014). Carbon dioxide is a major Greenhouse gas which is mainly blamed for the global warming usually constitute the highest volume of the total emissions (Moazzem et al, 2012). Figure 1 shows the global foot print for the CO2 gas from the year 1985 to the year 2025. ...
This paper attempts to summarize the simulation results of a steady-state for a natural gas sweetening based on absorption process using tetra ethylamine (TEA). Carbon dioxide (CO 2) capture simulation with the use of UNISIM software package was conducted using tetra ethylamine (TEA) to obtain sweet natural gas product that meets standard market specification. The amine weight predicted at 28% loading capacity of the process begins with an appropriate level of hydration for optimum absorption. The aim is to eliminate the CO 2 gas to at least 97% level of purity and achieve possible recovery of the amine solvent at the end of the process cycle. The results show that the CO2 gas stream increases with increasing feed temperature and flow rate. The end of the simulation result yields an optimization of 0.036 mole fraction for the CO2 gas and a total recovery of the TEA amine solvent. Equipment duty such as the cooler and lean pump were also determined to evaluate the success rate of the process. However, the amount of the CO2 in the final sweet gas can be affected by the TEA solvent, but it proves better performance than other solvents. In other to ascertain this, the percentage of the methane loss to the solvent was achieved at 0.00104 moles.
... Flue gases resulting from the combustion of fossil fuels are among the major sources of carbon dioxide (CO 2 ) and other greenhouse gases emitted into the atmosphere [1]. Flue gases are mixtures of water vapor (H 2 O), nitrogen (N 2 ), particulates, heavy metals, and acid gases (such as CO 2 and H 2 S). ...
This work attempts to address the quest of removing carbon dioxide from flue gas streams to help preserve the environment. It is based on a model that is able to describe the solid-liquid-vapour and solid-vapour phase equilibria for the ternary system of N2-O2-CO2 at pressures from 5 to 130 bar and over a wide range of temperature (140 to 220 K). Furthermore, a corresponding state-of-the art solid-vapor (SV) CO2 capture/separation unit is developed and introduced in this work. The SV unit was modeled using the Aspen Custom Modeler software by implementing the thermodynamic model developed before. It was then simulated using the Aspen Plus simulator; its performance was studied and analyzed. Moreover, the performance of the unit was optimized and compared to the most conventional corresponding technology used by the industry (i.e., amine-scrubbing). Results proved that for the same output clean gas composition, which contains only 0.3% CO2, the developed state-of-the-art SV unit consumes almost half of the energy required by the conventional process. Other advantages of the novel SV separation unit include the lower requirement of capital equipment, no need of additional agents (such as solvents) and the avoidance of product contamination with such additional agents.
... 7 One such alternative is to trap CO 2 from big sources such as thermal power plants (where each tonne of coal burned produces around 4 tonnes of CO 2 ) and prevent it from entering the atmosphere by appropriately capturing, storing, and converting it into useful chemicals/fuels. 8,9 At the moment, the widely available solution to address the CO 2 -related global warming problem is CO 2 capture and storage (CCS) at safe locations. 10,11 In comparison to CCS, CO 2 collecting and recycling (CCR) has been regarded as the most promising solution. ...
To seek sustainable CO2 sequestration and conversion, an electrochemical cell has been investigated for carbon capture and utilization strategy (CCU). In this cell, atmospheric CO2 is captured under ambient conditions and incorporated into power generation using zinc nanopowder as the catalyst. As a result, a method was developed to tune the electronic property of zinc by passing CO2. It was observed that nearly three orders of magnitude of conductivity could be changed along with achieving a carbon capture strategy. The system also exhibited good stability. In this process, it was observed that efficient current generation could be achieved due to zinc's active participation as a catalyst. The detailed physicochemical characterizations of catalysts were also examined. XRD, FTIR and TEM analysis perform the structural and morphological characterization. The system performance was further investigated using different criteria.
... Currently, the coal fired power plants generate the majority of the electricity worldwide and produce the highest rate of CO 2 per kilowatt hour (Table 4) [12]. Table 4. CO 2 emissions from several power generation technologies [12]. ...
... Currently, the coal fired power plants generate the majority of the electricity worldwide and produce the highest rate of CO 2 per kilowatt hour (Table 4) [12]. Table 4. CO 2 emissions from several power generation technologies [12]. ...
After years of decline, coal consumption has risen significantly in the last year (2021), driven mainly by the ever-increasing demand in fast-growing Asian countries and fostered by rising gas prices in Europe and the United States. Coal is both the largest electricity production source and the largest source of carbon dioxide emission. Coal-fired plants produce electricity by generating steam by burning coal in a boiler, but also large amounts of coal fly ash. Coal fly ash contains essential constituents for cement production, such as Ca, Si, Al, and Fe. Application of coal-fired ash to produce clinker at high doses may reduce the limestone content in the raw mix. Furthermore, coal fly ash is one of the industrial source materials utilized in the development of low-carbon cements and concretes on account of its chemical characteristics. The monitoring methodology is based fundamentally on the analysis of a set of variables (Na2Oe, Na2O, K2O, free CaO, and reactive silica content and fineness) over time. Weak relations between Na2O and K2O, and Na2Oe, and reactive silica content were found. This applied research has been done to verify previously done research. The scope of this paper is to assess the alkaline content of coal fly ash over a period of 10 years. The Na2O-equivalent of coal fly ash ranged from 0.35% to 2.53%, with an average value of 0.79%. These values should be taken into account producing concretes made with potentially reactive aggregates in order to mitigate the alkali–silica reaction (ASR).
... There are three main stages of CCS technologies: (1) pre-combustion, post-combustion, and oxy-fuel combustion with CO 2 (cf. Fig. 2), (2) transportation, and (3) storage [29]. For stage 1 (pre-combustion technology), the fuel source is initially transformed into syngas, a mixture of hydrogen (H 2 ) and carbon monoxide (CO). ...
... On the other hand, CO 2 is extracted from the flue gas stream at the exit for oxy-fuel combustion technology, mainly CO 2 and H 2 O. Among these three technologies, oxy-fuel combustion technology is simple since it only involves compression and cooling phases, and no additional solvents are necessary [29]. Afterwards, the captured CO 2 from the three technologies will be transported to a suitable storage site before being injected deep underground, where it will be stored safely and permanently away from the atmosphere. ...
... For example, Yahaya et al. (2004) compared the performance of CO 2 photoconversion toward C 3 H 5 OH over three different catalysts: TiO 2 , NiO, and ZnO, A higher yield of methanol (~175 µmol) was observed by the authors during 90 min reaction [10]. In other studies, Jiang [29]. ...
High exploitation of fossil fuel energy has resulted in substantial CO2 emissions into the atmosphere, leading to severe global warming. Tremendous strategies have been developed to explore possible approaches in minimizing the content of CO2 in the atmosphere. CO2 photoconversion into CH3OH has been put forward as a promising strategy since anthropogenic CO2 is utilized to generate valuable CH3OH assisting by clean solar energy. Silica-based materials have emerged as potential candidates for photocatalysts is accredited to their mesoporous framework with a large surface area, flexible tunability pore sizes, excellent thermal stability, and capability to suppress metal particle growth. Thus, this review encompasses the current progress on applying and developing silica-based materials as photocatalysts for CO2 photoconversion into CH3OH. Apart from that, fundamental aspects of the mechanism, the factors affecting performance, and the efficiency of silica-based materials in CO2 photoconversion to CH3OH are also comprehensively highlighted. The difficulties and prospects of CO2 photoconversion into CH3OH via silica-based materials are also discussed. In general, the most recent scenarios recommended further investigation to explore these materials since CO2 photoconversion to CH3OH has not been adequately investigated in the literature.
... Termik santrallerin çevreye duyarlılığını arttırmak için CO2 salınımını azaltma teknolojileri üzerine 2012 yılında Moazzem vd. bir çalışma yayınlamışlardır [5]. Şekil 1. Bir termik santralin çalışma prensibi [6] Termik santrallerin fosil yakıtları atmosfere yakmanın yan ürünü olan çok sayıda sera gazı ve kül pompaladığı bilinmektedir. ...
Dünya nüfusunun hızla artmasıyla birlikte gelişen sanayi ve teknolojik gelişmeler ihtiyaç duyulan enerjiyi de arttırmaktadır. İhtiyaç duyulan enerjinin en önemlilerinden bir tanesi elektrik enerjisidir. Elektrik enerjisini elde etmek için birçok farklı kaynak kullanılmaktadır. Kömür, elektrik enerjisi üretiminde dünyada en çok kullanılan kaynaktır. Ülkemizde de yüksek rezerviyle kömür birincil enerji kaynağı olarak karşımıza çıkmaktadır. Ancak son yıllarda artan küresel ısınma meteorolojik ekstrem olayları meydana getirmekte insanoğlunu olumsuz etkilemektedir. Küresel ısınmanın en önemli sebeplerinden biri olarak atmosfere salınan karbon olarak gösterilmektedir. Termik santraller kömürün yüksek sıcaklıkta yakılmasıyla yüksek karbon emisyonu üreten santrallerdir. Bu durum her ne kadar baca filtresi teknolojilerinin gelişmesiyle birlikte düşük emisyonlu termik santral gelişmelerini arttırsa da kaynağın tükenebilir fosil bir kaynak olması gerçeği ortadadır. Bu nedenle son enerjiyi doğadan sağlamak çevreci ve sürdürülebilir olması açısından önemlidir. Son yıllarda artan yenilenebilir enerji kaynaklarının (YEK) değerlendirilmesi konusunda büyük bir gelişme görülmüştür. Yenilenebilir enerji kaynakları arasında düşük ilk yatırım maliyeti, hızlı kendini geri ödeme süresi ve düşük karbon emisyonuyla hidroelektrik enerji santralleri (HES) dikkat çekmektedir. Ülkemiz su kaynakları açısından oldukça zengin bir ülke konumunda olduğundan sudan enerji konusunda yararlanma açısından büyük bir avantaja sahiptir. Bu çalışmada, termik santrallerle HES’lerin karbon emisyonu üzerine etkileri araştırılmıştır. Bu nedenle çalışmada, Eskişehir il sınırları içerisinde bulunan başka amaçlarla (sulama, taşkın, içme-kullanma suyu) işletilen Porsuk barajının HES’e dönüştürülmesi durumunda üretebileceği elektrik enerjisi ve karbon salınımına etkisi incelenmiştir.
... Among the various reasons for CO 2 generation, the most important is the use of fossil fuels for generating power. According to [2], 98% of CO 2 generation is generated by fossil-fueled power generating facilities [3]. One way to solve this problem is to diversify the fuel species to include biomass. ...
In order to implement moderate or intensive low oxygen dilution (MILD) combustion, it is necessary to extend the flame stability and operating range. In the present study, the conceptual designs of a combustor single nozzle and reformer were numerically suggested for a micro-gas turbine with an on-board reformer. The target micro-gas turbine achieved a thermal power of 150 kW and a turbine inlet temperature (TIT) of 1200 K. Studies on a nozzle and reformer applying an open-loop concept have been separately conducted. For the nozzle concept, a single down-scaled nozzle was applied based on a reference nozzle for a heavy-duty gas turbine. The nozzle can achieve a good mixture with a high swirl with a splined swirl curve lower NOx emissions and smaller pressure drop in the combustor. The concept of the non-catalytic partial-oxidation reforming reformate was designed using the combustor outlet temperature (COT) of the exhaust gas. Feasible hydrogen yields were mapped through the reformer. Based on the hydrogen yields from the reformer, hydrogen was added to the nozzle to investigate its combustion behavior. By increasing the hydrogen addition and decreasing the O2 fraction, the OH concentrations were decreased and widely distributed similar to the fundamental characteristics of MILD combustion.
... Besides, it was assumed that the pulverized coal particle would follow the air stream inside the coal mill as long as the lift forces provided by the hot air supplied from the boiler exceeds the gravitational force of each carried coal particle in the stream [9]. The flow can be also considered as a dilute mixture because the amount of inert particles is less than 10% of the air [26]. ...
... Meanwhile, the particle flow was solved using the discrete phase model (DPM) and Rosin-Rammler distribution function to simulate coal particles ranging from 25-300 µm. The DPM was valid because the mixture was diluted [26]. The numerical simulation settings were carried out repeatedly at different coal classifier blade angles. ...
Incomplete combustion in boilers often leads to a significant presence of unburnt carbon found in the ash and pollutant emissions. A key factor to overcome this problem is to increase the quality of classification via achieving a greater particle separation quality where at least 70% of the coal particles exiting the classifier are smaller than 75 μm. Three dimensional (3-D) computational fluid dynamics modeling was used to investigate the effect of the steepness of the classifier blade angle on the classification efficiency in Coal-Fired power plants. The gas flow inside the coal mill was solved by the realizable k-ε turbulence model (RKE) with a detailed 3-D classifier geometry meanwhile the discrete phase model was used to solve the coal particles flow. The steepest classifier blade angle of 40 o achieved the highest quality of classification where 61.70% of the coal particles are less than 75 μm. Meanwhile, the classification efficiency dipped to 93.0%. An increase in the quality of classification leads to a decrease in classification efficiency.
