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Kinematic viscosity of biodiesel fuel components and related compounds. Influence of compound structure and comparison to petrodiesel fuel components
Abstract
Biodiesel, defined as the mono-alkyl esters of vegetable oils and animal fats is an alternative diesel fuel that is steadily gaining attention and significance. One of the most important fuel properties of biodiesel and conventional diesel fuel derived from petroleum is viscosity, which is also an important property of lubricants. Ranges of acceptable kinematic viscosity are specified in various biodiesel and petrodiesel standards. In this work, the kinematic viscosity of numerous fatty compounds as well as components of petrodiesel were determined at 40 °C (ASTM D445) as this is the temperature prescribed in biodiesel and petrodiesel standards. The objective is to obtain a database on kinematic viscosity under identical conditions that can be used to define the influence of compound structure on kinematic viscosity. Kinematic viscosity increases with chain length of either the fatty acid or alcohol moiety in a fatty ester or in an aliphatic hydrocarbon. The increase in kinematic viscosity over a certain number of carbons is smaller in aliphatic hydrocarbons than in fatty compounds. The kinematic viscosity of unsaturated fatty compounds strongly depends on the nature and number of double bonds with double bond position affecting viscosity less. Terminal double bonds in aliphatic hydrocarbons have a comparatively small viscosity-reducing effect. Branching in the alcohol moiety does not significantly affect viscosity compared to straight-chain analogues. Free fatty acids or compounds with hydroxy groups possess significantly higher viscosity. The viscosity range of fatty compounds is greater than that of various hydrocarbons comprising petrodiesel. The effect of dibenzothiophene, a sulfur-containing compound found in petrodiesel fuel, on viscosity of toluene is less than that of fatty esters or long-chain aliphatic hydrocarbons. To further assess the influence of the nature of oxygenated moieties on kinematic viscosity, compounds with 10 carbons and varying oxygenated moieties were investigated. A reversal in the effect on viscosity of the carboxylic acid moiety vs. the alcohol moiety is noted for the C10 compounds compared to unsaturated C18 compounds. Overall, the sequence of influence on kinematic viscosity of oxygenated moieties is COOH≈C–OH>COOCH3≈CO>C–O–C> no oxygen.
... Several techniques have been recommended and biodiesel has emerged as an alternative, produced from different sources of oils and fats. 11,12 Biodiesel is basically composed of monoalkyl esters of fatty acids, obtained from renewable sources of vegetable oils and animal fats, using a catalyst and a short chain alcohol, in an esterification or transesterification reaction where the triglycerides are converted into esters of fatty acids, generating glycerin as a by-product. 13 In the transesterification reaction, the fatty acids present in the vegetable oil react with sodium methoxide (a mixture of methanol with sodium hydroxide) forming methyl esters fatty acids (FAME), thus yielding biodiesel. ...
... The objective was to establish the technological foundation for the national development of biodiesel. 12 From this program, law number 11.097 of January 13, 2005, established the commercial requirement of blending diesel fuel with 2% biodiesel (B2 blend) starting in early 2008. Since then, this proportion has increased over time and is currently at 12% (B12 blend), according to the National Agency of Petroleum, Natural Gas and Biofuels (ANP). ...
In the present work, cagaite (Eugenia dysenterica DC.) seed oil was studied as a potential inedible raw material for biodiesel production. The oil was extracted using a Soxhlet extractor and the fatty acids acyl esters that make up biodiesel were obtained by alkaline transesterification using sodium hydroxide. The influence of reaction parameters was also evaluated: molar ratio, time, and amount of catalyst. The conversion of fatty acids into fatty acid methyl esters (FAME), which make up biodiesel, was calculated using Nuclear Magnetic Resonance Spectroscopy (¹HNMR) spectra. In a 30 min reaction period, the molar ratio of oil to methanol was 1:4, resulting in a conversion of 63.57%. However, when the molar ratio was increased to 1:8, the conversion reached 81.74% during the same 30 min reaction period. After 60 min of reaction, additional increases in conversion were observed when molar ratios of 1:4, 1:6, and 1:8 were used. Under these conditions, the conversions achieved were 92.08%, 98.24%, and 98.78%, respectively. The physico‐chemical properties were evaluated and the results showed that cagaite seed oil biodiesel was similar to soybean biodiesel, which is the most commonly produced biodiesel in Brazil. It was thus an important substitute for soybean biodiesel.
... Therefore, the fuel with high density will be more in mass than the fuel with less density in the same volume [26,27]. In addition, the density of the fuel is important because it is related to viscosity, calorific value and cetane number [28,29]. The density of the fuel is also closely related to the amount of particulate matter emitted from the exhaust and NOx emissions. ...
... The cold filter plugging point is take part in EN 14214 standards. Each country can choose one of these two standards according to its own climatic conditions and seasonal conditions [28]. ...
Scientists continue to work in order to obtain clean and efficient energy in a sustainable and economical way. Biodiesel is an important research topic not only because it is a renewable energy source, but also because it is an environmentally friendly fuel that can be produced as efficiently as petroleum-derived fuels. The raw materials used are as important as the production parameters in the production of biodiesel fuels. Hemp is not a widely cultivated plant because its cultivation is subject to government control. However, by breeding, the production of species containing low amount of stimulant and high amount of seed and fiber can be realized. In case of an efficient fuel production in compliance with the determined standards, the hemp plant can be accepted as a raw material that can also be evaluated in the field of energy. In order to guide the studies to be carried out for this purpose, in this study, the conformity of the fuel obtained by producing biodiesel from hemp seed oil to the standards was examined. As a result of the fuel analysis, it has been seen that the fuel properties of the produced hemp biodiesel are largely compatible with the TS EN 14214 standards. The results obtained provided a sufficient starting point for the development of the study.
... The experimental kinematic viscosities for 76 fatty compounds as well as 29 components of petrodiesel, as determined according to ASTM D445 [30], at 40 • C were employed for the purpose of model training (Table S5) [31]. The best-fit correlations between experimental and calculated kinematic viscosities for a total 105 compounds are shown in Figure 7 on the basis of five-parameter expression as follows: ...
Mineral oils and synthetic and natural esters are the predominant insulating liquids in electrical equipment. Structure–activity relationship models to predict the key properties of pure insulating liquids, including pulse breakdown strengths, AC breakdown voltages, dielectric constants, flash points, and kinematic viscosities, have been proposed for the first time. Dependence of the specific properties on the molecular structures has been illustrated quantitatively in terms of surface area, statistical total variance, and average deviation of positive and negative electrostatic potentials, as augmented by molecular weight, volume, and ovality. Moreover, the individual contribution of the functional groups to viscosity has been revealed by an additive approach. The predicted properties are in good agreement with the experimental data. The present theoretical work provides new insights on the development of novel dielectric fluids.
... , the kinematic viscosity of the produced liquid samples spans from 4.23 cSt (for W90P10) to 3.79 cSt (for W10P90). This variance in viscosity is attributed to the formation of volatile, shorter-chain hydrocarbons resulting from the increased incorporation of waste plastic (WP) into the sample.51 Notably, the highest viscosity is recorded at 7.95 cSt in the fuel derived from the pyrolysis of WCO, labeled as W100 in theFigure 3b. ...
This study investigated the effects of different proportions of waste polyethylene (WP) and waste cooking oil (WCO) on the chemical and physical properties of the resulting co‐pyrolysis oil produced in an indigenously developed laboratory‐scale fixed bed batch‐type reactor. The proportion of WCO was altered in increments of 10% from 10% to 90%, and correspondingly, the proportion of WP was adjusted from 90% to 10% (by weight). The highest liquid fuel yield, reaching 70.9% by weight, was achieved using a 40:60 ratio of WCO to WP (W40P60) at a constant heating rate of 12°C and a temperature of 500°C. The obtained fuel exhibits promising properties, including a high calorific value (max HHV around 45.63 MJ/kg) and other advantageous properties such as low viscosity, low oxygen and nitrogen content, and absence of sulfur. Fourier‐transform infrared spectroscopy (FTIR) and gas chromatography–mass spectroscopy (GCMS) were examined on the resulting liquid fuel. The GC–MS spectra predominantly display alkanes, constituting approximately 41% by weight, and alkenes, making up roughly 20% by weight. These analyses revealed properties akin to commercial diesel, emphasizing the potential of waste cooking oil and waste polyethylene proportions in liquid diesel like fuel production.
... The flash properties of these liquid petrochemicals, distinguishing between low and high viscosity, are determined using ASTM methods D1310 and ASTM D93 [122]. Additionally, the Research Octane Number (RON) assesses their propensity for diesel knocking, while Kinematic Viscosity reflects the increase in these liquid petrochemicals' hydrocarbon chain lengths, with higher values indicating greater chain length [123]. API gravity, a key market demand factor for high-quality liquid petrochemicals, can be categorized into four classes: light (≥ 34), medium (25)(26)(27)(28)(29)(30)(31)(32)(33)(34), heavy (10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25), and extra heavy (≤ 10 Notably, the research octane number for these petrochemicals was determined to be 88.29, while the bromine number was found to be 34.03% ...
... This is because the diesel cut contains more products with a high number of carbon atoms, followed by kerosene and then gasoline. 47,49 As expected, viscosity decreased with an increase in temperature and is consistent with the literature. 45,48,50 In general, the viscosity of the cuts increased slightly with the increase in the bio-oil content in the feedstock. ...
... 20% methanol was used for treating both the oils. [7][11] [15] [16]. ...
Biodiesel, an alternative fuel is derived from the fats of animals and plants. As energy demand increases and fossil fuels are limited, research is directed towards alternative renewable fuels. Properties of waste oil (cotton seed oil and mustard oil) have been compared with the properties of petrodiesel, showing a comparable regime for satisfactory optimized blend which is to be selected for the better performance of a C.I. engine with biodiesel. The work presented in this paper is the study of characteristics of biodiesel prepared from vegetable oils (waste cotton seed oil and waste mustard oil). The characteristics of biodiesel are to be checked at different blends(B10, B15, B20) and select the optimum blend based on these characteristics. The characteristics include free fatty acid value, density, viscosity, flash point and fire point, cloud point and pour point, carbon residue content and ash residue content.
... Coconut oil can be utilized as an alternative fuel due to its close physical and chemical properties which are close to diesel. However high viscosity leads to carbon deposits, poor atomization, and fuel line clogging [10]. A study has been carried out in the past to reduce the viscosity by transesterification, diesel blending, and fuel additives [11]. ...
... It is a low pressure, low temperature reaction. It produces high conversion (> 95%) while reducing negative effects and has a quick reaction time [12]. With no actual intermediary components, it is a straight conversion to biodiesel. ...
Finding out how the trans-esterification process influences the chemical make-up and fuel quality of biodiesel made from Jatropha curcas L. seed oil is the main objective of this work. The extracted Jatropha oil was characterized by GC-MS and ICP technique and American Oil Chemist Society standards were used to study its physicochemical properties. Due to the fact that every physicochemical property does not meet WHO specifications, it has been determined to be non-edible oil; these findings demonstrate that the high oil content (30 %) and free fatty acid composition of Jatropha seed oil make it a potential source for biodiesel synthesis. By varying the quantities of CH4OH and NaOH, as well as the temperature and reaction duration, the optimum reaction for biodiesel production using this approach has been studied. GC/MS was used to confirm the biodiesel's identity. The American Society for Testing and Materials (ASTM) requirements were used to establish the physicochemical properties of biodiesel samples (MJ1-MJ15), and it was discovered that they were within the acceptable ranges required for the operation of diesel engines except for ash, water content, and cetane number for MJ1 and MJ15 biodiesel sample. Treatment of the biodiesel with anhydrous sodium sulphate improves the physicochemical properties of all samples; it brought all qualities into compliance for application in engines powered by diesel. By optimizing the conditions of transestrification, a high-quality biodiesel (cetane number = 61.8) has been synthesized with the highest fatty acids methyl ester content, which has recorded for the MJ6 biodiesel. This work is licensed under a Creative Commons Attribution Non-Commercial 4.0 International License.
... We identified at least 4 compounds that were present in both hydrophilic and hydrophobic candle soot: pentadecane, cetene, n-hexadecanoic acid (palmitic acid), and octadecanoic acid (stearic acid). Pentadecane and cetene were straight-chain hydrocarbons [29], while palmitic and stearic acids were saturated fatty acids [30]. Some compounds were specific to either hydrophilic or hydrophobic candle soot and were not found in both. ...
The effect of candle soot colloids, a novel nanomaterial from candle combustion that we developed previously, on tomato (Solanum lycopersicum) seed germination and seedling vigor was investigated. Candle soot colloids were applied at different concentrations and hydrophobicities to tomato seeds and germination parameters and seedling vigor characteristics, such as length, fresh weight, dry weight, chlorophyll, and carotenoids, were measured. It was found that candle soot colloids significantly improved germination speed, seedling length, and seedling fresh weight compared to the control. The adherence of soot particles to the trichomes on the seed surface, which may help seeds retain moisture and stay hydrated, was observed. The chemical composition of the soot samples was analyzed using gas chromatography-time of flight mass spectrometry and two different chemical constituents in hydrophilic and hydrophobic soot samples that may affect seed germination were identified. A new potential use of candle soot colloids as plant growth-promoting agents and insights into the effects of nanomaterials on plant physiology and biochemistry were revealed by this study.
... By the time when liquid surface reached to the lower mark, stopwatch was stopped and the time flow was recorded. The viscosity of water also determined similarly using the flow rate and viscosity of each sample was calculated [34]. ...
Diminishing fossil fuel reserves have stimulated research into biofuel as potential renewable and sustainable replacements for fossil diesel. The present research aims to characterize and investigate the behavior of mineral diesel and biodiesel blends. The biodiesel oil was prepared from sunflower oil collected from the local market. Binary blends of mineral diesel and biodiesel in various proportions were prepared, e.g. 5%, 10%, 15%, 20%, 25%, and named as B5, B10, B15, B20, B25. Their various physicochemical properties were measured using standard ASTM/API methods, including specific gravity, API gravity, cloud point, pour point, aniline point, flash point, fire point, diesel index, viscosity, and distillation behavior. API gravity, aniline point, and diesel index decrease as the amount of biodiesel blended increases in the blend, while pour point, cloud point, flash point, fire point, and specific gravity increase with an increase in the amount of biodiesel blended in the commercial diesel oils.
... By the time when liquid surface reached to the lower mark, stopwatch was stopped and the time flow was recorded. The viscosity of water also determined similarly using the flow rate and viscosity of each sample was calculated [34]. ...
Diminishing fossil fuel reserves have stimulated research into biofuel as potential renewable and sustainable replacements
for fossil diesel. The present research aims to characterize and investigate the behavior of mineral diesel and biodiesel
blends. The biodiesel oil was prepared from sunflower oil collected from the local market. Binary blends of mineral diesel
and biodiesel in various proportions were prepared, e.g. 5%, 10%, 15%, 20%, 25%, and named as B5, B10, B15, B20, B25.
Their various physicochemical properties were measured using standard ASTM/API methods, including specific gravity,
API gravity, cloud point, pour point, aniline point, flash point, fire point, diesel index, viscosity, and distillation behavior.
API gravity, aniline point, and diesel index decrease as the amount of biodiesel blended increases in the blend, while pour
point, cloud point, flash point, fire point, and specific gravity increase with an increase in the amount of biodiesel blended
in the commercial diesel oils.
... Moreover, perennials are preferred to annuals for liquid biofuel production by reducing annual management costs and by producing better viscous liquid biofuel. The jatropha oil as a perennial plant is a potential fuel because of its lower viscosity of 34-36 cST as compared to other plant oils like cottonseed (36 cST) and sunflower (43 cST) [34,35]. ...
Background
The production of liquid biofuel in Eastern Africa countries has the potential to play an important role on the global biofuel markets in the coming years, because transportation fuel demand is expected to grow. Despite the presence of suitable environmental conditions for bioenergy crop cultivation in Eastern Africa, liquid biofuel production has been restricted by different factors, including market situation and government policies. The objective of this review is to evaluate the potential markets, policies, strategies, and plans for liquid biofuel production in some Eastern Africa countries, including Ethiopia, Kenya, Sudan, Tanzania and Uganda.
Main text
Over 64 scientific articles and reports published between 2002 and 2023 related to liquid biofuel production market and policies were collected from internet search engines and unpublished grey literatures and reviewed. Since liquid biofuel production was in early stage of investment in Eastern Africa countries by 2020, all the countries showed similar restrictions. It was found that the global market demand for liquid biofuel increased after 1980s. For example, although Ethiopia started bioethanol production in 1950s, the production was discouraged by the lack of a market. Biofuel trade is globally determined by the biofuel policies of industrialized countries, which are mainly driven by the willingness to reduce emissions and to tackle volatile fossil fuel prices. Eastern Africa liquid biofuels has a number of market openings, including rural domestic use, substituting fossil fuel imports, and supplying the European market. There are also attractive legal conditions and political willingness to invest in the production of liquid biofuels. However, institutional weaknesses hindered the possibility to coordinate liquid biofuel production. The lack of adequate domestic institutions, coordination mechanisms, and robust monitoring resulted in land-use conflicts, corruption, and technical challenges. Appropriate policy measures are required to local land use determination, selection of appropriate type of bioenergy crops, and biofuel processing types and scales. In particular, small and large-scale biofuel production projects are required to include biofuel production in the conventional agricultural farming practices.
Conclusions
Good governance is highly important for bioenergy crop production, liquid biofuel processing and consumption in the whole liquid biofuel value chain. Moreover, it is important to exchange good practices through cooperation, including—but not limited to—intra-African countries, which would accelerate the learning process and the deployment of effective measures and mechanisms. There should be biofuel value chain upgrading to overcome fragmentation and inconsistency of measures; match-making between demand and supply at domestic, intra-African, and internationally with proper public awareness creation.
... In contrast with diesel fuel, biodiesel use is beneficial in reducing carbon buildup and wear and tear of key engine components [22]. However, compared to fossil diesel, biodiesel frequently has a higher viscosity, poor atomizing characteristics, high cold filtration point [23], and poor fluidity in the environment, resulting in difficult application, whereas biodiesel has both a high and a low impact on the amount of NO x in engine exhaust. As shown by Murillo S. et al. [24], the biodiesel-diesel blend fuel was made from different proportions of cooking oils. ...
Pollutants produced by engines are a significant source of environmental pollution, so the study of engine emissions is very important. In this study, with CONVERGE software, a diesel engine model of the engine was produced. To better obtain the characteristic results of the engine, this was coupled with an improved chemical kinetics mechanism. Then, the results of this model were verified experimentally. Additionally, the effects of four different EGR rates on the combustion, performance, and emissions of a dual-fuel diesel engine were investigated by the verified model under different (50 %, 75 %, and 100 %) load conditions. Lastly, the brake specific fuel consumption, NOx emission, and HC emission were optimized by the response surface methodology (RSM). The results show that the pressure, temperature, and NOx emission in the engine's cylinder can all be reduced by raising the EGR at three different loads. Besides, the optimization results show that the engine achieves the best operating conditions at 100 % load, hydrogen fraction of 6.92 %, and EGR rate of 7.68 %.
... Similarly, the research focus has been on transesterification processes, and various strategies to tailor the fatty acid profile of the algae have been proposed. The fatty acid chain length reduction was vital to produce biodiesel with finer fuel properties that comply with specific standards and, hence, enriching the short chain fatty acids and medium chain fatty acids could potentially increase the fuel properties of the produced biodiesel (Knothe and Steidley 2005). For instance, medium chain fatty acids such as lauric acid (C12:0) and myristic acid (C14:0) have been increased by seven-fold and four-fold, respectively, by using combinatorial expression platform comprising plant lauric acidbiased TE and MCFA-specific ketoacyl-ACP synthase in Dunaliella tertiolecta (Lin et al. 2018). ...
Algae exhibit distinguishing potential of producing various products from fuels to wide range of value-added products, described in the present book as phycochemicals. Few decades of research analyzed several pathways of converting microalgal biomass into bioproducts. The product conversion efficiency, sustainability, and economics of the production processes depend on the type of reactions opted and catalyst used for producing the targeted product. Catalyst plays vital role in overall economics and yield of the target product. For biofuel production, chemical and biological catalysts were extensively researched. The inherent disadvantages of homogeneous catalysts include tough separation from the reaction system and thermal instability which increased the heterogeneous catalyst applications. On the other hand, green catalysts are increasingly attractive that are mainly made from biomass, especially enzymes which are effective and environmentally friendly. The term “phycocatalysts” can be identified as the catalysts made from algal biomass and are emerging recently due to their exquisite catalytic potential and acting as another value-added choice for integrated microalgal biorefinery. Moreover, both nanocatalysts and biocatalysts are widely attractive due to plentiful of advantages such as easy synthesis, simple disposal, and high reusability, along with enhanced yield of the desired product. Deep eutectic solvent (DES) and cyanobacteria which are recent intrigue in the field of catalysis were also discussed in the chapter. Thus, catalysts have become indispensable in algal biomass conversion which influences the yield of every algal product synthesis/recovery which have been elucidated elaborately in this chapter.
... Similarly, Almedia (2014) reported that the kinematic viscosity value of biodiesel derived from waste frying oil was found to be higher according to EN 14214 standard. This may be attributed to the partial hydrogenation of waste frying oil, resulting in a higher proportion of trans fatty acid chains (Knothe, 2005). Falizi (2019) investigated the effects of different irrigation schedules on the production of refined safflower oil from safflower seeds and reported that the viscosity value of biodiesel produced from these refined oils varied between 4.81-5.77 ...
This study examined the fuel properties of biodiesels derived from safflower (Carthamus tinctorius L.) crude and refined oils, as well as those produced from waste safflower crude oil and waste safflower refined oil generated from frying. Biodiesel produced from safflower crude oil, refined oil, waste crude oil and waste refined oil, respectively; Density at 15°C (883.2)-(896.3)-(889.8)-(877.9) kg m-3, kinematic viscosity at 40°C (4.57)-(5.55)-(5.72)-(4.86) mm2s-1 cold filter plugging point (SFTN) (-8), (-9), (-12), (-11) °C, calorific value ((39.857)-(39.137)-(39.095)-(39.508) MJ kg-1, flash point (160)-(150)-(180)-(180)°C, water content (398)-(386)-(206)-(243) mg kg-1, colour (ASTM D1500) (
... Ini sesuai dengan ekspektasi, mengingat bahwa salah satu kelemahan utama dari biodiesel, termasuk dari minyak jarak dan minyak sawit, adalah viskositasnya yang lebih tinggi dibandingkan dengan solar konvensional (Agarwal & Agarwal, 2007). Viskositas yang lebih tinggi dapat mempengaruhi sifat pelumasan dan aliran bahan bakar dalam sistem mesin, yang pada akhirnya bisa berdampak pada efisiensi dan performa mesin (Hoekman et al., 2012;Knothe & Steidley, 2005). ...
Pertumbuhan ekonomi dan bertambahnya jumlah penduduk berdampak pada peningkatan kebutuhan energi dari berbagai sektor. Bahan bakar fosil adalah sumber yang paling banyak digunakan namun tidak terbarukan. Perlunya sumber energi alternatif yang dapat diperbaharui sebagai pengganti bahan bakar fosil. Biodiesel merupakan bahan bakar alternatif pengganti minyak solar, dapat dihasilkan dari transesterifikasi minyak nabati atau lemak hewani. Penelitian ini bertujuan untuk mengetahui sifat fisik dan karakteristik injeksi bahan bakar. Bahan bakar yang digunakan adalah campuran biodiesel minyak jarak-sawit dan solar. Penelitian ini menggunakan variasi sampel bahan bakar B5, B10, B15 dan B20 serta solar murni sebagai pembanding. Hasil penelitian menunjukkan bahwa viskositas dan densitas mempengaruhi karakteristik injeksi bahan bakar. Semakin tinggi viskositasnya, semakin sempit sudut injeksi bahan bakarnya.
... Unlike the cetane number, the viscosity increases with the carbon chain length and saturation. The presence of C23:0 (28.71%) in yeast biodiesel raises its kinematic viscosity and contributes to problems, e.g., engine deposits [80,81]. ...
The European Union has recommended that about 10-50% of the global energy requirement should be supplemented by waste biomass resources by 2050 in order to achieve the objective of having net-zero-emission economies. This has led to intensive research being conducted on developing appropriate biofuel production technologies using advanced or integrated systems to tackle local, national, and global energy challenges using waste feedstock. Researchers have realized the potential of microbes (e.g., yeast strains) for bioenergy production. For this paper, both non-oleaginous and oleaginous yeasts were reviewed, with a specific focus being placed on their diversity in metabolism and tolerance to the various challenges that arise from the use of waste feedstock and influence bioprocessing. Gathering in-depth knowledge and information on yeast metabolism has paved the way for newer and better technologies to employ them for consolidated biorefineries to not only produce biofuels but also to cut down process expenses and decrease the risks of net carbon emissions. The rationale for using yeast strains improved by metabolic engineering and genetic manipulation that can substantially meet the challenges of alternate fuel resources is also described in this paper. This literature review presents the advantages and disadvantages of yeast-based biofuel production and highlights the advancements in technologies and how they contrast to conventional methods. Over the last decade, scientific publications have endorsed the idea of biorefineries for environmentally friendly, cost-effective, and sustainable biofuel production.
... Whereas the viscosity of SEBF is 3.40 mm 2 /s at 40 • C because it is made up of a complex mixture of higher paraffinic hydrocarbon in the range of C 10 -C 16 . It has been shown by Knothe and Steidley (2005) ( Table 9) that viscosity increases with increasing number of carbon atoms among the alkanes (Paraffinic hydrocarbons). However, the increase in kinematic viscosity due to increase in chain length among fatty acid esters is not linear. ...
... It is necessary to investigate the spraying of liquid fuels of bio-origin because their properties are distinctly different from those of conventional fuels. For instance, the high viscosity of biodiesel obtained through the transesterification of vegetable oils with monohydric alcohols worsens the spraying characteristics of droplets, and the fuel does not mix well with the air in the engine during ignition [70,71]. It is possible to improve the spraying of biodiesel by reducing the kinematic viscosity and surface tension by adding alcohol [72]. ...
The problems of environmental pollution caused by the operation of power plants and engines motivate researchers to develop new biofuels. The environmental aspect of composite biofuels appears to have great potential because of the carbon neutrality of plant raw materials. This study analyzes recent advances in the production of biofuels and their application. The research findings on the properties of promising plant raw materials and their derivatives have been systematized. The most important stages (spraying, ignition, and combustion) of using biofuels and mixtures based on them in internal combustion engines have been analyzed. A separate section reviews the findings on the environmental aspect of using new fuel compositions. Most studies show great prospects for involving bio-components in the development of composite fuels. The real issue is to adjust existing engines and plants to non-conventional fuel mixtures. Another big problem is the increased viscosity and density of biofuels and oils, as well as the ambiguous effect of additives on burnout completeness and emissions. The impact of the new kinds of fuels on the condition of components and parts of engines, corrosion, and wear remains understudied. The interrelation of industrial process stages (from feedstock to an engine and a plant) has not been closely examined for composite liquid fuels. It is important to organize the available data and develop unified and adaptive technologies. Within the framework of this review work, scientific approaches to solving the above problems were considered and systematized.
... Whereas the caprylate oil iso-propyl ester (COIPE) has higher cloud and pour point values because it is a highly saturated ester compound. Saturated esters have higher melting point than unsaturated ones and thus higher cloud and pour point values [35,36]. ...
... The kinematic viscosity of a commercial biodiesel sample (methyl soyate) is 4.09 mm 2 s −1 , while that of petrol-diesel fuels is 1.54 mm 2 s −1 . 18 The kinematic viscosities of the oils were higher than that of petrol diesel (2.5-3.2 mm 2 s −1 at 40°C), possibly due to the fatty acid composition and molecular weight of the oils. 19 ...
This study presents an approach to produce biodiesel from Elaeis guineensis using natural heterogeneous catalysts derived from raw, calcined, and acid-activated forms of waste snail shells. The catalysts were thoroughly characterized using SEM, and process parameters were systematically evaluated during biodiesel production. Our results demonstrate a remarkable crop oil yield of 58.87%, with kinetic studies confirming second-order kinetics and activation energies of 43.70 kJ mol-1 and 45.70 kJ mol-1 for methylation and ethylation, respectively. SEM analysis identified the calcined catalyst as the most effective, exhibiting remarkable reusability for continuous reactions running up to five times. Moreover, the acid concentration from exhaust fumes yielded a low acid value (B100 0.0012 g dm-3), significantly lower than that of petroleum diesel, while the fuel properties and blends satisfied the ASTM standards. The sample-heavy metals were well within acceptable limits, confirming the quality and safety of the final product. Our modelling and optimization approach produced a remarkably low mean squared error (MSE) and a high coefficient of determination (R), providing strong evidence for the viability of this approach at an industrial scale. Our results represent a significant input in sustainable biodiesel production and underscore the enormous potential of natural heterogeneous catalysts derived from waste snail shells for achieving sustainable and environmentally friendly biodiesel production.
... Conversely, some studies demonstrated a different trend. Rakopoulos et al. (2006) and Knothe and Steidley (2005) found a fall in NOx emission while utilising ethyl alcohol and bioethanol blends in diesel engines. By making use of four-cylinder, 4-stroke CI engine, several quaternary fuel mixtures consisting of diesel, bio-diesel, vegetable-based bio-diesel, and higher alcohol were assessed (Yilmaz et al. 2018). ...
Incorporating jatropha biodiesel into discarded plastic oil and diesel on diesel engines and analysis of six fuel samples, three diesel types and two waste plastic diesel and jatropha biodiesel combinations. Following characterisation, a one-cylinder, DI diesel engine underwent comprehensive performance and emissions testing, involving spectroscopy. Addition of jatropha biodiesel led to reduced viscosity and density of the waste plastic-diesel blend, a 20% decrease in flash point, and 10% reductions in BSEC and BSFC, while lowering the engine's thermal efficiency by 5%. Jatropha biodiesel increased HC by 30%, reduced CO and NOx emissions by 20% and 5%. Both diesel and WPF20D60JB20 exhibited a of 36.45%, with BSEC values at full load of 9.91 and 9.84 MJ/kW-hr. WPF20D60JB20 demonstrated the best performance.
... According to Havet et al. (2001), the area of the protected surface rises as a result of the film's thickness due to the length of the fatty acid chain. These protective layers can increase lubricity and decrease thermal energy in sliding contact (Knothe and Steidley, 2005). ...
Lubrication is necessary to minimise the frictional impact created during the running of a vehicle since it increases wear and friction among the parts in contact. Wear and friction shorten the component's life, decrease its dependability, and raise maintenance costs. The current study uses a tribo tester to examine the friction and wear properties of rapeseed biodiesel at fixed parameters. The investigated lubricants included B0 (diesel), B100 (biodiesel), and four distinct blends of biodiesel: B15, B30, B45, and B60. Analysis was done for one hour at ambient temperature with a standard load of 140 N at a speed of 1000 rpm. The outcome showed that as the concentration of biodiesel augmented, friction and wear scar get reduced. The aluminium pin wear in B100 appeared 16% less than that in diesel. Also, the presence of esters and fatty acids during Fourier transform infrared analysis of biodiesel contributes more to its possibilities as a lubricant.
... The higher the viscosity, the lower the spray cone angle, and the higher the spray penetration and droplet size [50]. In terms of the chemical structures, the long saturated straight chain moieties, either of fatty acids, alcohols, or both, may increase biodiesel's kinematic viscosity [51]. ...
The first aim of this paper is to study the influence of four parameters of the transesterification reaction—reaction temperature (40–80 °C), time (1–3 h), the molar ratio of 1-octanol to sunflower oil (4:1–10:1) and mass fraction of the catalyst (1–3 wt%)—on the conversion of oil to biodiesel (octyl esters of fatty acids), with potassium hydroxide as a catalyst. The highest conversion, of 99.2%, was obtained at 60 °C, a molar ratio of 1-octanol to sunflower oil of 10:1, and with 2 wt% of the catalyst after an hour. The optimal conditions determined with response surface methodology (RSM) when aiming for the lowest possible parameter values and a conversion of 95% or higher were a temperature of 40 °C, time of 1 h, 1-octanol to oil molar ratio at 8.11:1 and mass fraction of catalyst of 2.01%. Furthermore, post-synthesis and purification (>99%), the application properties of pure fatty acid octyl esters (FAOCE) and their blends with mineral diesel and 1-octanol were evaluated. Standardized tests were conducted to measure the fuel’s density, viscosity, cold filter plugging point (CFPP), and lubricity. The addition of FAOCE in mineral diesel increases its density, viscosity, and lubricity. When added up to 20 vol%, FAOCE did not have an influence on the blend’s CFPP value. Still, all the blend property values fell within the limits required by standard EN 590.
... Also, temperature is one of the key factors that have influence on the density of the liquid as large change in the density at higher temperatures affect the atomization and combustion processes of the engine (Knotheet al., (2005), Tate et al., (2006)and Knothe and Steidley, 2005) carried out investigations on the varying effects of temperature on density of methyl soyate, rapeseed methyl ester and ethyl ester of fish oil and found out that with an increase in temperature, the density decreases linearly and at 300oC the density was as low as 0.5 gcm -3 . Geller and Goodrum (2004) opined that the longer the fatty acid chains, the more saturated the molecules and this would automatically result into higher viscosity. ...
Viscosity and density are important properties that qualify biodiesel fuel to serve as an alternative fuel because all other properties directly or indirectly depend on them. The processes involved in determining the viscosity and density of biodiesel are relatively simple and costly and there are discrepancies in the results obtained due to the differences in the oil composition of the feed-stocks used as against the reported cause of experimental errors. This work aimed at theoretically determining and developing relationship between the density and viscosity of different feed-stocks and the fatty acid methyl ester composition at different temperatures.In the study, density and viscosity data of biodiesel fuels and the composition of FAME were collected from literatures. A linear regression analysis was carried out for density and viscosity on the average values of viscosity and density data obtained at different temperatures range (10°C-40°C) of FAME composition. Equations relating density and viscosity with the percentage composition by weight of FAME of biodiesel fuel were developed. Predicted mean values for kinematic viscosity and density were respectively between 4.31 - 5.64 mm2/s and 861.67 – 885.66 kg/m3. The developed equations were able to predict with up to 97.1% accuracy for viscosity and 98.5% accuracy for density. The developed equations could effectively predict the quality of biodiesel (viscosity and density) from various feedstocks based on FAME compositions
... For example, Fig. 4 D interestingly shows that the presence of 1-eicosanol was correlated to samples with higher viscosities. This finding is in agreement with previous work, which showed that saturated fatty acids increases fuel viscosity and can lead to the formation of carbon deposits inside of engines [54] . Likewise, long chain alkanes like tetradecane were correlated with larger measurements for hydrogen content and heat of combustion while substituted naphthalenes and cycloalkanes were correlated with lower values for hydrogen content and heat of combustion ( Fig. 4 E-F). ...
Chemometric methods like partial least squares (PLS) regression are valuable for correlating sample-based differences hidden in comprehensive two-dimensional gas chromatography (GC × GC) data to independently measured physicochemical properties. Herein, this work establishes the first implementation of tile-based variance ranking as a selective data reduction methodology to improve PLS modeling performance of 58 diverse aerospace fuels. Tile-based variance ranking discovered a total of 521 analytes with a square of the relative standard deviation (RSD2) in signal between 0.07 to 22.84. The goodness-of-fit for the models were determined by their normalized root-mean-square error of cross-validation (NRMSECV) and normalized root-mean-square error of prediction (NRMSEP). PLS models developed for viscosity, hydrogen content, and heat of combustion using all 521 features discovered by tile-based variance ranking had a respective NRMSECV (NRMSEP) equal to 10.5 % (10.2 %), 8.3 % (7.6 %), and 13.1 % (13.5 %). In contrast, use of a single-grid binning scheme, a common data reduction strategy for PLS analysis, resulted in less accurate models for viscosity (NRMSECV = 14.2 %; NRMSEP = 14.3 %), hydrogen content (NRMSECV = 12.1 %; NRMSEP = 11.0 %), and heat of combustion (NRMSECV = 14.4 %; NRMSEP = 13.6 %). Further, the features discovered by tile-based variance ranking can be optimized for each PLS model with RReliefF analysis, a machine learning algorithm. RReliefF feature optimization selected 48, 125, and 172 analytes out of the original 521 discovered by tile-based variance ranking to model viscosity, hydrogen content, and heat of combustion, respectively. The RReliefF optimized features developed highly accurate property-composition models for viscosity (NRMSECV = 7.9 %; NRMSEP = 5.8 %), hydrogen content (NRMSECV = 7.0 %; NRMSEP = 4.9 %), heat of combustion (NRMSECV = 7.9 %; NRMSEP = 8.4 %). This work also demonstrates that processing the chromatograms with a tile-based approach allows the analyst to directly identify the analytes of importance in a PLS model. Coupling tile-based feature selection with PLS analysis allows for deeper understanding in any property-composition study.
... That can be attributed to the catalytic effect of Mn(NO 3 ) 2 and Co(NO 3 ) 2 on the Jatropha oil. Increasing the catalyst amount increases the cracking extent of the fatty acid chains in the oil and consequently decreases the produced carbon chain length, which decreases their viscosity [45]. ...
In this study, Jatropha oil was catalytically cracked using Co(NO3)2 and Mn(NO3)2 as heterogeneous catalysts at different ratios of 0.5%–3% to obtain different grades of biofuel. The physical and fuel properties of the obtained biofuels were characterized by measuring the following properties: density, viscosity, specific gravity, pour point, flash and fire points, cetane number, carbon and ash residues and sulfur content. The determined properties were located within the limits of the specific standards of ASTM specifications. The type of transition metal and the ratio of the used catalysts were greatly affect the physical and fuel properties of the obtained biofuels. Comparing the reactivity of (Co(NO3)2 and Mn(NO3)2) as catalytic cracking catalysts revealed that Co(NO3)2 is more reactive than Mn(NO3)2. Using of low catalysts ratio produced biofuel comparable to biodiesel according to ASTM specifications; while higher catalyst ratio produced biofuel comparable to bio-gasoline. Lighter fractions of the biofuel in the range of gasoline were produced at higher catalysts ratios and the optimum concentration was 3%. The reactivity of the two salts was discussed based on their electronic configurations.
... Also, temperature is one of the key factors that have influence on the density of the liquid as large change in the density at higher temperatures affect the atomization and combustion processes of the engine (Knotheet al., (2005), Tate et al., (2006)and Knothe and Steidley, 2005) carried out investigations on the varying effects of temperature on density of methyl soyate, rapeseed methyl ester and ethyl ester of fish oil and found out that with an increase in temperature, the density decreases linearly and at 300oC the density was as low as 0.5 gcm -3 . Geller and Goodrum (2004) opined that the longer the fatty acid chains, the more saturated the molecules and this would automatically result into higher viscosity. ...
Viscosity and density are important properties that qualify biodiesel fuel to serve as an alternative fuel because all other properties directly or indirectly depend on them. The processes involved in determining the viscosity and density of biodiesel are relatively simple and costly and there are discrepancies in the results obtained due to the differences in the oil composition of the feed-stocks used as against
the reported cause of experimental errors. This work aimed at theoretically determining and developing a relationship between the density and viscosity of different feed-stocks and the fatty acid methyl ester composition at different temperatures. In the study, density and viscosity data of biodiesel fuels and the composition of FAME were collected from literatures. A linear regression analysis was carried out for density and viscosity on the average values of viscosity and density
data obtained at different temperatures range (10˚C-40˚C) of FAME
composition. Equations relating density and viscosity with the
percentage composition by weight of FAME of biodiesel fuel were
developed. Predicted mean values for kinematic viscosity and density
were respectively between 4.31 - 5.64 mm2/s and 861.67 – 885.66
kg/m3. The developed equations were able to predict with up to 97.1%
accuracy for viscosity and 98.5% accuracy for density. The developed
equations could effectively predict the quality of biodiesel (viscosity
and density) from various feedstocks based on FAME composition
... d Cetane number data from Schenk et al. (2008). e Kinematic viscosity data from Knothe (2005); Knothe and Steidley (2005); Gouw et al. (1966). f Heat of combustion data from Freedman and Bagby (1989); Weast (1986 amount of saturated fatty esters of N. salina is about 17.5%. ...
Nannochloropsis salina was cultured batch-wise to evaluate the potential of the alga to produce biodiesel. The cells were harvested at the end of the exponential growth phase when the concentration was 18 · 10⁶ cells/mL culture. The growth estimated as dry weight from this cell number was (3.8 ± 0.7) mg/L. The lipid and triglyceride contents were 40% and 12% on a dry weight basis, respectively. The amount of the ratio triglycerides/total lipids was approximately 0.3.
The composition of triglyceride fatty acid methyl esters (biodiesel) was analysed by gasliquid chromatography and identified as: C14:0, C16:0, C16:1, C18:0, C18:1, C18:2, C18:3, C20:1, and C20:5. The ratio of unsaturated to saturated fatty acid contents was approximately 4.4. Additionally, the characterization of each individual fatty acid ester was discussed with regard to the fuel properties of biodiesel produced by the alga.
The thermo-kinetic aspects of 3-hydroxybutyric acid (3-HBA) pyrolysis in the gas phasewere investigated using density functional theory (DFT), specifically the M06-2X theoreticallevel in conjunction with the cc-pVTZ basis set. The obtained data were compared withbenchmark CBS-QB3 results. The degradation mechanism was divided into 16 pathways,comprising 6 complex fissions and 10 barrierless reactions. Energy profiles were calculatedand supplemented with computations of rate coefficients and branching ratios over thetemperature range of 600–1700 K at a pressure of 1 bar using transition state theory (TST)and Rice-Ramsperger-Kassel-Marcus (RRKM) methods. Thermodynamics results indicatedthe presence of six stable conformers within a 4 kcal mol1 energy range. The estimatedchemical kinetics results suggested that TST and RRKM approaches are comparable,providing confidence in our calculations. The branching ratio analysis reveals that thedehydration reaction pathway leading to the formation of H2O and CH3CH=CHCO2Hdominates entirely at T ≤ 650 K. At these temperatures, there is a minor contribution from thesimple homolytic bond fission reaction, yielding related radicals [CH3CHOH+CH2CO2H].However, at T ≥ 700 K, this reaction becomes the primary decomposition route. At T = 1700K, there is a minor involvement of a reaction pathway resulting in the formation ofCH3CH(OH)CH2+CHO(OH) with an approximate contribution of 16 %, and a reactionleading to [CH3+CH2OHCH2CO2H] with around 9 %.
Microalgal oil has been described as the raw material with the greatest potential for third-generation biodiesel production, without competing with arable land suitable for food production. The fuel quality of biodiesel depends on the raw materials, the reagents used, and the values of the operational variables in the transesterification.
ASTM D6751 and EN 14214 standards describe the limits of biodiesel properties values such as Cetane Number (CN), Oxidation Stability (OS), Kinematic Viscosity (KV), Acid Value (AV), Iodine Value (IV), and Cold Flow Properties. These properties are highly influenced by the chain length and degree of unsaturation of the Fatty Acid Methyl Esters (FAMEs) that constitute biodiesel. The CN represents the ignition quality of biodiesel in the engine, high cetane value is the indicator of better combustion and low emission of nitrous oxide. In general, the presence of long-chain FAMEs with a high proportion of saturated fatty acids (SFA) increases CN and improves oxidative stability. In contrast, biodiesel with a relatively high content of monounsaturated fatty acids (MUFA) or polyunsaturated fatty acids (PUFA) tends to perform better in cold climates.
Microalgae have a significantly higher yield of lipids, compared to conventional crops for biodiesel production; however, the fatty acid composition varies with the species of microalgae and may differ in the size of the carbon chain and/or in the presence and amount of unsaturation. Thus, to choose the most suitable microalgae for biodiesel production, other factors such as the fatty acid composition must be evaluated.
This chapter gives detailed information about parameters to consider for improving microalgae biodiesel properties. In addition, updated research, challenges, and strategies to improve its quality are also presented.
In recent years, vegetables and plant-based edible oils have received a lot of attention owing to the presence of high amounts of mono-, and polyunsaturated fatty acids (MUFA, and PUFA) in a balanced diet, and their various domestic and industrial applications. Canola oil is a kind of vegetable oil derived from rapeseed. Canola (rapeseed) is the world's third-largest oilseed crop, trailing behind only soybean and cottonseed. It contains a smaller amount of non-polymerizing saturated fatty acids, which means it has superior edible characteristics. Further, it contains 6–14% α-linolenic acid, 50–65% oleic acid, and 7% saturated fatty acids. It also contains omega-3 and omega-6 fatty acids, making it one of the most useful cooking oils in the market. Canola oil contains a high amount of vitamins K and E, and it helps to reduce skin issues and indications of aging such as acne, fine lines, wrinkles, blemishes, and spots. It shows strong physico-chemical and function properties. This chapter reviews and addresses the availability (production and consumption), physico-chemical and functional properties of canola oil as an additive which facilitate its application in various fields including composites and coatings, biodiesel production, and food. It also discusses about canola oil refining and its processing, nutritional properties, and health benefits. This up-to-date review will be very helpful in selecting and using canola oil effectively and in a sustainable manner for various domestic and industrial applications including in biocomposites.
This study investigates the utilization of an α-MnO2/nanocarbon ball (NCB) additive to enhance the performance of second-, third-, and fourth-generation biodiesels (SSGB, PVB, and GMCB). Various tests including XRD, XPS, TEM, HRTEM, BET, torque and power measurements, EGT, BTE, emissions analysis (CO2, CO, HC, soot, and NOx), and BSFC were conducted. The combination of GMCB5N50 with α-MnO2/NCB yielded the highest torque (35.77 N m) and power (6.47 kW), indicating an improved engine performance. GMCB5N50 exhibited efficient combustion with a peak pressure of 76.04 bar. The nanoadditive also demonstrated significant reduction in BSFC, achieving up to 34% improvement in fuel efficiency. When GMCB20N50 was used, the highest BTE values were observed, reaching approximately 39.5%. EGT values for GMCB5N50 were only slightly elevated compared to pure diesel. Notably, GMCB20N50 showcased substantial decreases in emissions, including carbon dioxide (CO2: 55% reduction), carbon monoxide (CO: 35% reduction), hydrocarbons (HC: 58% reduction), and soot (98% reduction), indicating a promising direction for the development of low-emission alternative fuels. The investigation of the effects of the oxygen lattice, surface area, and oxygen adsorption on engine performance and emission reduction revealed their positive contributions. These findings highlight the potential of the studied α-MnO2/NCB additive for improving biodiesel performance and advancing the development of sustainable and environmentally friendly fuels.
The current chapter presents a review of heavy metal pollution in Ukraine based on a literature analysis of Ukrainian national reports and three main scientific resources: ISI Web of Science, Scopus, and Google Scholar. It was found that Pb, Cr, and Cu are the dominant contaminants/pollutants in almost all regions of Ukraine. The Kharkiv, Zaporizhia, Donetsk, and Chernivtsi regions of Ukraine have a high level of Cr because of the high concentration of industries found there. In many areas of Ukrainian territory, the content of Ni, Zn, and Co in the soil is less than the maximal permissible level. It is important to note that the violent conflict in Ukraine during 2022 may contribute to an increase in heavy metals pollution of already polluted areas with Pb, Ni, Cr, and Cu. From the presented data and their analysis, it is clear that current military conflict influence may increase the content of heavy metals in the air, water, and soil. Such tendency is dangerous for Ukrainian regions with already high levels of heavy metals. It is recommended that modern technologies of phytoremediation should be used together with crop rotation of plants to combat hyperaccumulators of heavy metals in highly contaminated areas. In Ukraine, sunflower, rapeseed, and soybean are the most widespread crops for production of non-edible vegetable oil (2G), which can be used for biofuel production and phytoremediation processes, as well. The oilseed crops in Ukraine have been discussed as sources of biodiesel, but this usually depends on the crops being amenable to the regional climate. The comparative characteristics of different quality parameters of biodiesel from the United States, Brazil, European Union countries, and Ukraine are presented.
Thermo-kinetic aspects of 3-Hydroxybutanoic acid (3-HBA) pyrolysis in the gas phase have been studied computationally in the temperature range 600–1700 K and pressure of 1 bar using the ab initio CBS-QB3 method and M06-2X/cc-pvTZ level with the aid of the Gaussian 09 program and the Kinetic and Statistical Thermodynamical Package (KiSThelP). The degradation mechanism was divided into seventeen pathways: seven complex fissions and ten barrierless reactions. Chemical kinetics simulations of barrier reactions are calculated using transition state theory (TST) and unimolecular Rice-Ramsperger-Kassel-Marcus (RRKM) theories, while the kinetics of barrier reactions are estimated using the accurate classical method. Thermodynamics results indicate six stable conformers within 4 kcal mol− 1. To confirm the chemical stability of these conformers, the HOMO-LUMOs energy gaps were checked. The estimated chemical kinetics results indicated that TST and RRKM are comparable which gives confidence to our calculations. Branching ratio analysis shows the full dominance of the dehydration reaction R4 at T ≤ 650 K, with a minor contribution for the simple bond fission R9. At T ≥700 K, R9 became the main decomposition route, with a small contribution from R10 (~ 16% at 1700 K) and R8 (~ 9% at 1700 K) reactions.
Soybean oil is an abundant commodity crop that has garnered attention for its use as a feedstock for sustainable materials. Soybean oil is high in polyunsaturated fatty acid content, which can promote undesirable properties in biodiesel and lubricant applications. In this work, we characterized the fatty acid composition of commercial soybean oil along with two other soybean oil varieties, Ellis and TN18‐4110. Ellis and commercial soybean oils had similar fatty acid compositions, while TN18‐4110 was enriched in the monounsaturated oleic acid. Biodiesel and estolides were prepared from the three varieties and the relevant physical properties were measured. In comparison to commercial soybean diesel, both Ellis and TN18‐4110 exhibited unique advantages. As estolide‐based lubricants, all three varieties had advantageous cold flow properties, but TN18‐4110 also possessed excellent oxidative stability and lower viscosity. The physical properties and structural property relationships of the biodiesel and estolides are discussed.
In this work it is shown how the entropy scaling paradigm introduced by Rosenfeld (Phys Rev A 15:2545–2549, 1977, https://doi.org/10.1103/PhysRevA.15.2545) can be extended to calculate the viscosities of branched alkanes by group contribution methods (GCM), making the technique more predictive. Two equations of state (EoS) requiring only a few adjustable parameters (Lee–Kesler–Plöcker and PC-SAFT) were used to calculate the thermodynamic properties of linear and branched alkanes. These EOS models were combined with first-order and second-order group contribution methods to obtain the fluid-specific scaling factor allowing the scaled viscosity values to be mapped onto the generalized correlation developed by Yang et al. (J Chem Eng Data 66:1385–1398, 2021, https://doi.org/10.1021/acs.jced.0c01009) The second-order scheme offers a more accurate estimation of the fluid-specific scaling factor, and overall the method yields an AARD of 10 % versus 8.8 % when the fluid-specific scaling factor is fit directly to the experimental data. More accurate results are obtained when using the PC-SAFT EoS, and the GCM generally out-performs other estimation schemes proposed in the literature for the fluid-specific scaling factor.
Microemulsification and blending are two viscosity‐modifying techniques of vegetable oils for direct use with diesel engine. In this study, alcohol blends are mixtures of ethanol, diesel, and palm‐oil biodiesel while microemulsion biofuels are thermodynamically stable, clear, and single‐phase mixtures of diesel, palm oil, and ethanol stabilized by surfactants and cosurfactants. Although there are many studies on biofuels lately, there is limited research on using biodiesel as a surfactant in microemulsion formulations and applied on engine performance at different engine loads. Therefore, the objectives are to investigate phase stability and fuel properties of formulated biofuels (various blends and microemulsions), to determine the engine performance at different engine loads (no load, and from 0.5 to 2.0 kW), and to estimate laboratory‐scale cost of the selected biofuels compared to diesel and biodiesel. The results showed that phase stability and fuel properties of selected microemulsion biofuels are comparable to diesel and biodiesel. These microemulsion biofuels can be applied to the diesel engine at different loads while diesel‐ethanol blends and palm‐oil‐biodiesel‐ethanol blends cannot be. It was found that the energy efficiencies of the system using microemulsion biofuels were slightly lower than the average energy efficiency of diesel engine. From this study, it can be summarized that microemulsion biofuels can be formulated using palm‐oil biodiesel (palm‐oil methyl ester) as a bio‐based surfactant and they can be considered as environmentally‐friendly alternatives to diesel and biodiesel. However, cost considerations showed that the raw materials should be locally available to reduce additional costs of microemulsion biofuels.
This chapter reviews competing technologies for converting vegetable oils and animal fats into diesel fuel besides biodiesel. Aside from transesterification to produce biodiesel, microemulsion/co-solvent blending and hydroprocessing (deoxygenation) appear to be the two most promising approaches for converting vegetable oils and fats into alternative diesel fuels. Microemulsion or co-solvent blend hybrid fuels is a relatively low-cost conversion process since it requires little more than the mixing of individual components at ambient temperature. Transesterification generally requires a slightly elevated temperature; a minimum reaction time, depending on catalyst; and several product separation and washing steps to prepare the biodiesel for distribution. Similarly, hydroprocessing generally requires elevated temperature and hydrogen pressure; a minimum reaction time, depending on catalyst; condensation; and the fractionation of liquid products. Although hydroprocessing and transesterification may be economically competitive with each other, it is unlikely either approach will compare favorably with hybrid fuel formulation. Other advantages favoring hybrid fuel formulation over transesterification or hydroprocessing include adaptability to large-scale continuous flow processing equipment, no catalysts to recover or re-generate, no excess alcohol, no by- or co-products, and no product separation/fractionation steps. All compounds, including amphiphiles used in hybrid fuel formulations, may be derived from renewable agricultural feedstocks. Another disadvantage for hydroprocessing is the likelihood that it has an unfavorable energy balance. Life cycle analyses for biodiesel generally indicate that it gives back more than three times the energy required to produce it resulting in a net positive energy balance.
This paper presents the impact of the addition of specific types of fatty acid derivatives on the lubrication properties of low sulfur diesel fuels. It discusses the most recent results, concerning the influence of adding low amounts of four specific types of biodiesel and two tertiary amides on the tribological behavior of the steel-on-steel systems, lubricated with low-sulfur automotive diesel. Experiments were carried out on the HFRR test rig. The obtained wear results have clearly shown a specific behavior of the components tested, which dissolved in selected base fuels at the concentration range of 0.05−10%. It is concluded that a very small amount of the selected biodiesel types and tertiary amides dramatically improves the low-sulfur diesel lubricity.
One of the main problems in the study or industrial application of transesterification processes for vegetable oils is how
to measure the methyl ester content. In this work, a quick analytical method was developed for assessing the methyl ester
content of purified “fuel grade” transesterification products by applying a simple correlation with viscosity. The correlation
was tested on a wide range of samples with various methyl ester contents; the results were in agreement with the values measured
by gas-chromatographic analysis. In a defined range of weight fractions the correlation allows for the determination of the
methyl ester content of purified transesterification products by a single viscosity measurement. This method is especially
suitable for process control purposes as it determines the methyl ester content quickly and simply.
Several novel fatty diesters with bulky moieties were synthesized by esterification of mono- or bifunctional fatty acids or
with mono- or bifunctional alcohols using p-toluenesulfonic acid as catalyst. They were characterized by 1H and 13C nuclear magnetic resonance as well as positive chemical ionization (PCl) mass spectrometry. The PCl mass spectra of the
resulting diol diesters and diacid diesters are discussed and compared. The compounds were investigated as potential additives
for improving the cold flow properties of vegetable oil esters used as biodiesel.
Diesel fuel injection pumps are lubricated primarily by the fuel itself. Traditionally, fuel viscosity was used as a rough indicator of a fuel's ability to provide wear protection, but since the advent of low sulphur diesel, even some fuels of higher viscosity have been found capable of producing wear. This paper provides further insights into the main contributors to diesel fuel lubricity, their source and the impact of refinery processing. The most effective way to monitor lubricity is also considered. We have found that diesel lubricity is largely provided by trace levels of naturally occurring polar compounds which form a protective layer on the metal surface. Typical sulphur compounds do not confer this wear protection themselves rather it is the nitrogen and oxygen containing hetero-compounds that are most important. A complex mixture of polar compounds is found in diesel and some are more active than others. The process of hydrotreating to reduce sulphur levels also destroys some of these natural lubricants. Other refinery processes also influence the concentration of the lubricity agents in the final fuel blend. Lubricity additives have been developed to compensate for the deterioration in natural lubricity observed in low S diesels. The interaction between natural polars and lubricity additive has been investigated and the findings may explain why some poor lubricity fuels are more responsive to lubricity additive than other. Difficulties are encountered when using knowledge of refinery streams to predict the lubricity of a diesel blend. The most effective way to monitor lubricity performance is by making measurements on the finished fuels. Vehicle tests have shown that the High Frequency Reciprocating Rig is a good indicator of diesel lubricity performance.
Rheology of fatty acid methyl esters of soyabean, used-soyabean, mustard and used-mustard oils has been examined experimentally in the temperature range of -3 to 15°C. Such a low temperature is encountered in the use of these fatty esters as diesel fuels. These fatty esters were prepared in the laboratory by the transesterification of oils with methanol in the presence of sodium hydroxide as a catalyst. Brookfield Synchro-Lectric Viscometer has been used to observe the dependence of shear rate, time, temperature on the apparent viscosity of these fatty esters. Kerosine works satisfactorily as the bath fluid in the Ultra Cryostat for the desired temperature range. The fatty acid methyl esters of soyabean, used-soyabean, mustard and used-mustard oils are found to behave as Newtonian fluids above a temperature of about 5°C. Below this temperature, they are expected to behave as pseudoplastic fluids. These methyl esters also exhibit a thixotropic behaviour. The decrease in the apparent viscosity of these methyl esters with increase in temperature is approximately exponential.
The fourth edition of this reference volume gives the property values for more than six hundred pure chemicals and also provides a critical survey of the most reliable estimating methods. The book further demonstrates how to estimate physical and thermodynamic properties when experimental data are not available. Physical properties include critical constants, vapor pressures, viscosities, diffusion coefficients, and surface tension, thermodynamic properties include densities, enthalpies, entropies, fugacity coefficients, and heat capacities. Techniques for estimating vapor/liquid and liquid/liquid equilibria for separation operations such as distillation, absorption, and extraction, are also covered.
Densities, kinematic and dynamic viscosities, excess molar volumes, and viscosity deviations of binary mixtures of a methyl ester (pentanoate, hexanoate, or heptanoate) and an alkane (octane, decane, or dodecane) were determined at (283.15, 293.15, 303.15, and 313.15) K and atmospheric pressure for the whole compostion range. Excess molar volumes were compared to those predicted by the group-contribution model of Nitta et al. employing three different parameter sets available in the literature. The best predictions were obtained using the primary parameter set. The experimental kinematic viscosities were used to test the group-contribution models UNIVAC and UNIFAC−VISCO, and the best predictions were obtained by means of the UNIFAC−VISCO model. Also, several empirical and semiempirical relationships were employed to correlate the composition−viscosity data.
Densities, ρ, viscosities, η, and refractive indices, nD, for binary mixtures of hexane, decane, hexadecane, and squalane with benzene were measured over the whole composition range at 298.15 K and atmospheric pressure. The excess molar volumes, , and viscosity deviations, δη, were calculated from experimental measurements. These result were further fitted to the Redlich−Kister equation to estimate the binary coefficients and standard errors. The effects of chain length and branching of alkanes on and δη values have been discussed.
As the use of biodiesel becomes more wide-spread, engine manufacturers have expressed concern about biodiesel’s higher viscosity.
In particular, they are concerned that biodiesel may exhibit different viscosity-temperature characteristics that could result
in higher fuel injection pressures at low engine operating temperatures. This study presents data for the kinematic viscosity
of biodiesel and its blends with No. 1 and No. 2 diesel fuels at 75, 50, and 20% biodiesel, from close to their melting point
to 100°C. The results indicate that while their viscosity is higher, biodiesel and its blends demonstrate temperature-dependent
behavior similar to that of No. 1 and No. 2 diesel fuels. Equations of the same general form are shown to correlate viscosity
data for both biodiesel and diesel fuel, and for their blends. A blending equation is presented that allows the kinematic
viscosity to be calculated as a function of the biodiesel fraction.
Kinematic viscosities at 20C, 40C and at 70C have been measured for methyl oleate, linoleate, linolenate, erucate, and for
the saturated fatty acid methyl esters acetate through nonadecanoate. Using a recently developed dynamic viscosity-temperature
criterion, log (1.200+log η)=A−S log (1+t/135), the viscosity-temperature behavior of the saturated compounds could be characterized
by one single parameter.
Data for viscosity as a function of temperature from 24 to 110°C (75 to 230°F) have been measured for a number of vegetable
oils (crambe, rapeseed, corn, soybean, milk-weed, coconut, lesquerella) and eight fatty acids in the range from C9 to C22. The viscosity measurements were performed according to ASTM test methods D 445 and D 446. Several correlations were fitted
to the experimental data. Correlation constants for the best fit are presented. The range of temperature in which the correlations
are valid is from 24°C (75°F), or the melting point of the substance, to 110°C (230°F). The correlation constants are valuable
for designing or evaluating such chemical process equipment as heat exchangers, reactors, distillation columns, mixing vessels
and process piping.
Summary 1. Kinetic studies showed that concurrent oxidatioD of preformed hydroperoxides may be expected to take place at all stages of the autoxidation of methyl lino- leate. The rate of oxidation relative to the rate of autoxidation of unoxidized ester is determined chiefly by the extent of the accumulation of hydroperoxides. 2. Infrared spectral analysis of hydroperoxides oxidized to various degrees indicated that trans, trans diene conjugation and isolated trans double bonds produced in the autoxidation of methyl linoleate are related to the concurrent oxidation of the accumu- lated hydroperoxides. 3. The low absorptivity observed for diene conju- gation, compared to that which may be expected for the exclusive production of cis, trans diene conjugated hydroperoxide isomers during the autoxidation of methyl linoleate is attributed to the concurrent oxida- tion of accumulated hydroperoxides. 4. The effect of antioxidants in giving a well- defined induction period in the oxidation of hydro- peroxides isolated from autoxidized methyl linoleate
Physical characterizations of (1) the ethyl esters of the naturally occurring C6−C18 saturated fat acids and (2) the ethanoate esters of the saturated alcohols corresponding to the above acids have been made.
They are a) refractive indices at 20°, 25°, 30°, 35°, and 40°C., b) densities and viscosities at 35°, 50°, 65°, 80°, and 95°
C., and c) boiling points at several pressures.
The physical characteristics exhibited by the two series of esters are quite similar. However the actual values obtained for
the ethanoate esters are slightly higher than those obtained for the corresponding ethyl esters.
1.
Determinations of surface tension, interfacial tension against water, viscosity, density, and refractive index were made at
75°C. for the saturated, evennumbered,n-fatty acids from C2 through C18 and for the corresponding methyl and ethyl esters. The typical effect of temperature on the various physical constants was
demonstrated for one of the fatty acids, myristic acid.
2.
Surface tensions of the fatty acids were found to increase from 19.6 dynes/cm. for acetic to 27.7 dynes/cm. for stearic as
the length of the carbon chain increased. Surface tensions for the ethyl esters were about 2.5 dynes/cm. lower than those
for the corresponding acids, while the surface tensions for the methyl esters were about 2 dynes/cm. lower.
3.
The interfacial tensions of the fatty acids and esters against water increased with increasing length of the fatty acid chain.
The interfacial tension values for the acids were lower than those for the corresponding esters. For the longer chain length
acids, increase in chain length had very little effect on the interfacial tension.
4.
The viscosities of the fatty acids and esters increased as the number of carbon atoms in the fatty acid chain increased. Because
of molecular association the acids were most viscous, and their viscosity increased most rapidly with increasing chain length.
Only small and consistent differences were found in the viscosities of corresponding methyl and ethyl esters.
5.
The densities of the fatty acids and esters decreased with increasing chain length, the decrease being most marked for the
fatty acids and least marked for the ethyl esters. No decrease in density of the ethyl ester series was detectable beyond
the butyrate.
6.
The refractive indices of the fatty acids and esters increased rapidly with increasing chain length. The refractive indices
of the acids were greater than those for the corresponding esters, and at the longer chain lengths the refractive indices
for corresponding methyl and ethyl esters were almost identical.
The chemical composition, molecular configuration, and crystal structure of fatty acid molecules contribute to the more than
twenty distinct physical properties associated with this class of organic compounds. This discussion will be limited to only
a few of these fatty acid properties and will include melting and solidification phenomena, vapor pressure-boiling point relationships
and solubility behavior of fatty acids.
Viscosity data have been obtained as a function of temperature for seven fatty acids (pelargonic, capric, lauric, myristic,
palmitic, stearic, and oleic) and four triglycerides (tricaprilin, tripalmitin, tristearin, and triolein) and their binary
mixtures at temperatures from above their melting points to 90°C. The viscosity measurements were performed by using Cannon
Fenske glass capillary kinematic viscometers. Modified versions of the Andrade equation were used to correlate the kinematic
viscosities of pure fatty acids and pure triglycerides. The MacAllister method was used for their binary mixtures. The correlation
constants are valuable for designing or evaluating chemical process equipment, such as heat exchangers, reactors, distillation
columns, and process piping.
The cetane number, a widely used diesel fuel quality parameter related to the ignition delay time (and combustion quality) of a fuel, has been applied to alternative diesel fuels such as biodiesel and its components. In this work, the cetane numbers of 29 samples of straight-chain and branched C1–C4 esters as well as 2-ethylhexyl esters of various common fatty acids were determined. The cetane numbers of these esters are not significantly affected by branching in the alcohol moiety. Therefore, branched esters, which improve the cold-flow properties of biodiesel, can be employed without greatly influencing ignition properties compared to the more common methyl esters. Unsaturation in the fatty acid chain was again the most significant factor causing lower cetane numbers. Cetane numbers were determined in an ignition quality tester (IQT) which is a newly developed, automated rapid method using only small amounts of material. The IQT is as applicable to biodiesel and its components as previous cetane-testing methods.
Viscosity is one of the most significant properties to affect the utilization of biodiesel fuels. This paper presents a method, which has been verified experimentally, for predicting the viscosities of biodiesel fuels from the knowledge of their fatty acid composition. The applicability of a logarithmic mixture equation was verified using controlled mixtures of standard fatty acid esters and natural biodiesels. Several binary, ternary and quaternary mixtures of fatty acid ethyl ester (FAEE) gas chromatography (GC) standards were formulated. Their viscosities were predicted from their component values and were within ±3.7% of their measured values. The fatty acid compositions of six typical oils were simulated by mixing fatty acid methyl ester (FAME) standards in appropriate amounts. Viscosities of these mixtures were also predicted within ±2.1% of their measured values. Five biodiesel types were produced from natural oils and the logarithmic equation was applied to predict their viscosities. An average prediction error of ±3% was obtained for these samples. The viscosities of fifteen biodiesel types were then predicted based on their fatty acid composition as published in the literature and were found to vary as much as 100% This is most likely a principal contributing factor to the variation in performance of some biodiesel fuel types. The viscosity of biodiesel fuels reduce considerably with increase in unsaturation. Contamination with small amounts of glycerides significantly affects the viscosity of biodiesel fuels.
Seven members of this homologous series have been studied by differential scanning calorimetry (DSC), and their melting point, enthalpy and entropy of fusion obtained. The entropy change for each additional carbon-carbon bond in the aliphatic acid chain closely observed the value R•ln3, as expected for flexible molecules. IR spectra of crystalline glycidyl miristate, palmitate and stearate showed the typical band progression in the 1180 - 1350 cm-1 region and a doublet at ca. 720 ± 10 cm-1. Glycidyl esters appeared appeared to be free of polymorphism since no differences in the behavior of solids crystallized from solvent or from the melt were observed either by DSC or by IR spectroscopy.
We studied the production of fatty acid ethyl esters from castor oil using n-hexane as solvent and two commercial lipases, Novozym 435 and Lipozyme IM, as catalysts. For this purpose, a Taguchi experimental design was adopted considering the following variables: temperature (35-65 degrees C), water (0-10 wt/wt%), and enzyme (5-20 wt/wt%) concentrations and oil-to-ethanol molar ratio (1:3 to 1:10). An empirical model was then built so as to assess the main and cross-variable effects on the reaction conversion and also to maximize biodiesel production for each enzyme. For the system containing Novozym 435 as catalyst the maximum conversion obtained was 81.4% at 65 degrees C, enzyme concentration of 20 wt/wt%, water concentration of 0 wt/wt%, and oil-to-ethanol molar ratio of 1:10. When the catalyst was Lipozyme IM, a conversion as high as 98% was obtained at 65 degrees C, enzyme concentration of 20 wt/wt%, water concentration of 0 wt/wt%, and oil-to-ethanol molar ratio of 1:3.
Heattransfercharacteristics offattyacids
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EN590. Automotive fuels-diesel-requirements and test methods. Berlin, Germany: Beuth-Verlag.
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Evaluation of the lubricity of soybean oil-based additives in diesel fuel
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