Cold Flow Properties Research Articles

Synthesis and evaluation of benzyl methacrylate-methacrylate copolymers as pour point depressant in diesel fuel

The cold-flow properties of diesel fuel are considered as the determining factors of diesel utilization and popularization. Pour-point depressants (PPDs) are often added to diesel to remediate issues with fluidity in cold climates. In this study, a series of benzyl methacrylate-methacrylate copolymers (MB-R1MC, R1 = C12, C14, C16, C18) and benzyl methacrylate-tetradecyl methacrylate (MB-C14MC) in different molar ratios of the functional monomers (1:1, 1:5, 1:10, 1:15, and 1:20) was synthesized by radical polymerization and characterized by gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance (1H NMR). The depression effects of these PPDs in diesel were investigated and compared with previous reports. Results showed that diesel treated with 3000 ppm MB-C14MC (1:10) exhibited the best depression on solid point and cold filter-plugging point (CFPP) by 26 and 12 °C, respectively, and the CFPP depression was evidently superior to that in a previous research. Moreover, the action mechanism was explored by differential scanning calorimeter, polarizing optical microscopy and rheology analysis. Results showed that the nonpolar component of PPDs co-crystallized with n-alkanes and provided large number of crystallization sites in diesel, whereas the polar components adsorbed on the wax crystal surface, thereby changing the shape, decreasing the size, and increasing the dispersity of wax crystal. Therefore, MB-C14MC copolymer was confirmed to be an excellent PPD of diesel fuel.

Investigation of Correlation Between Diesel Fuel Cold Operability and Standardized Cold Flow Properties

Role of diesel fuel in the mobility is unquestionable despite of diesel scandal. There are several approaches to substitute partially at least it, but in commercial utilization the real alternative is not found yet. Diesel fuel main disadvantage beside the environmental factors is the application properties in cold weather. In the presented research there is an overview and evaluation about the main classification methods of winter properties of diesel. The result is, that CFPP and CP have lower and lower correlation with the newest engine technologies and a new method would be necessary to able to predict the winter behavior of diesel in real conditions. In the paper a specification of a new test equipment is presented.

Experimental investigation of the effect of fatty acids configuration, chain length, branching and degree of unsaturation on biodiesel fuel properties obtained from lauric oils, high-oleic and high-linoleic vegetable oil biomass

A very good understanding of the structure, level, type and physical property relationships of fatty acids in plants oils and their methyl esters (FAMEs) is of utmost importance when selecting vegetable oils for a particular desired biodiesel quality that meets the operating condition requirements of the compression-ignition diesel engine and the climatic dictate of the environment under which the engine is operated. It is on this premise that the degree of influence of fatty acid configuration, chain length, branching and unsaturation on cold flow and critical properties of biodiesel was investigated. The critical properties studied include: saponification and cetane number, iodine value, higher heating values, density, flash point and kinematic viscosity. The feed stock consists of three groups of vegetable oil biomass. The group one is made up of highly saturated, lauric coconut and palm kernel oils while group two consists of high linoleic, soyabean and corn oil biomass with low percentage of mono-unsaturated and high percentage of poly-unsaturated fatty acid. High oleic olive and canola oil constituted the third group of biomass. The triglycerides in these oils were converted to methyl esters by alkali-catalyzed transesterification reaction under standard conditions. The fatty acid methyl esters (FAMEs) compositional analyses of these feed stocks was done by using Agilent, HP 6890 Gas Chromatograph equipped with Flame ionization detector and 6890 Auto Sampler that connects with a controller box (GC-FID). The various biodiesel cold flow behaviour and critical properties under investigation were evaluated by the American society for testing materials (ASTM D6751-07b) and the European union (EN 14214) standard procedures and techniques.Better cold flow behaviour was exhibited by biomass with higher degree of unsaturation, longer chain length, higher degree of branching and with cis configuration. While critical properties showed a lot of variations based on fatty acid profile.

Integrated valorization of Moringa oleifera and waste Phoenix dactylifera L. dates as potential feedstocks for biofuels production from Algerian Sahara: An experimental perspective

Abstract The world is concerned with the degradation of the Saharan eco-system due to the absence of green spaces, emission of greenhouse gases and the burial of oases by sand beside the global energy crisis. This promoted the Algerian government to set a national strategy towards the use of renewable sources to cover 40% of its energy needs by 2030. In this article, a modern technique to simultaneously protect the environment and produce biofuels from the Saharan environment through cultivation of Moringa oleifera and valorizations of waste Phoenix dactylifera L. dates which are of not of satisfactory quality for the local market has been adopted. Characterization of Moringa oleifera oil, Moringa oleifera biodiesel and bioethanol produced from the waste date was done. Biodiesel-diesel-bioethanol blends were characterized by DSC, FT-IR, TGA and GC methods. Results show high oil content of Moringa oleifera seeds of 40%, biodiesel yield of 91% and bioethanol percentage of 96.83% with 3.17% of impurities. The properties of ternary blends of D80B5BE15, D80B10BE10 and D80B15BE5 exhibit similar densities and cold flow properties to Euro-diesel. Our analysis also proved that waste Phoenix dactylifera L. dates are useless as ruminant feed due to low protein content. In conclusion, the study proved the feasibility of cultivating Moringa oleifera to protect the environment and valorizing its seeds besides waste date seeds to produce both biodiesel and bioethanol in the Algerian Saharan.

Microbial lipids from cellulolytic oleaginous fungus Penicillium citrinum PKB20 as a potential feedstock for biodiesel production

Microbial lipids derived from oleaginous fungi are considered as an alternative feedstock for biodiesel production. We attempt to isolate a cellulolytic oleaginous fungi as a potential feedstock for biodiesel production. The fungus was identified by 5.8 S-ITS rRNA gene sequencing. The extracellular enzyme activities were recorded after every 24 h for 7 days. Nile red staining and fluorescence microscopy was used to visualise the lipid bodies within the fungal hyphae. A renewable heterogeneous base catalyst derived from Musa balbisiana cola peels was used for the transesterification of Penicillium citrinum PKB20 derived oil into biodiesel. GC-MS analysis was used to analyse the fatty acid methyl esters (FAME) profile of the transesterified lipids. Penicillium citrinum PKB20 was isolated from detritus rich soil of Assam, India. The endoglucanase, xylanase and β-glucosidase enzyme activities were found to be 292.83 ± 0.29, 111.72 ± 0.45 and 6.54 ± 0.13 U/mg respectively. The specific enzyme activity for extracellular lipase was found to be 3.12 ± 0.16 U/mg. It could accumulate up to 60.61% of lipids in nitrogen-limited medium (7.34 ± 0.45 g/L biomass production). The extracted lipids were converted to biodiesel with 89.3% conversion efficiency. The predominant fatty acids were oleic acid (30.09%), palmitic acid (20.25%) and linoleic acid (33.14%) suggesting a balance between oxidative stability and cold flow properties for suitable biodiesel quality. Penicillium citrinum PKB20 was found to be a potential feedstock for biodiesel production with desirable fuel properties. The cellulolytic nature could be utilised for simultaneous lipid production directly on cellulosic substrates.

Selection of microalgae species based on their lipid content, fatty acid profile and apparent fuel properties for biodiesel production

Different microalgae species produce varying quantity and quality of the lipids. Fatty acid methyl ester composition, which comprises both saturated and unsaturated contents, critically affects biodiesel properties. Current study compares six locally isolated microalgae strains belonging to three classes (Trebouxiophyceae, Chlorophyceae, and Cyanophyceae) on the basis of lipid content and biodiesel properties. All the six species are grown in similar condition up to the late stationary phase, and their lipid content and fatty acid methyl ester composition are measured experimentally. Multi-criteria decision analysis (MCDA) tool has ranked Calothrix species (class Cyanophyceae) on the top, owing to better cetane number, density and oxidation stability; whereas Chlorococcum species (class Chlorophyceae) is ranked second because of its higher lipid content, better cold flow property, and low viscosity. Property analysis of these two species is extended in the enlarge temperature range for five properties, vapor pressure, latent heat of vaporization, liquid density, liquid viscosity and vapor diffusivity, which are important in spray and combustion modeling. It is found through detailed property estimation that Chlorococcum sp. is a more suitable species in comparison with Calothrix sp. as it is having better properties and its lipid content is much higher than that of Calothrix sp. Although the properties of microalgae biodiesel are poorer in comparison with conventional diesel fuel, a greater number of such studies will help in understanding the requisite changes as required for microalgae biodiesel-based engine and their properties as compared with conventional diesel.

Catalytic esterification, kinetics, and cold flow properties of isobutyl palmitate

Isobutyl palmitate was synthesized by the esterification of palmitic acid and isobutanol with pyridine n-butyl bisulfate ionic liquid as the catalyst in a self-designed reactor. The kinetics of the esterification and cold flow properties of biodiesel were also studied. The optimal reaction conditions for the esterification are as follows: catalyst dosage, 6%; reaction time, 60 min; molar ratio of isobutanol to palmitic acid, 5:1; and reaction temperature, 100 °C. The verification test was conducted under the optimal conditions, and the esterification rate was up to 98.79%. The kinetics of catalytic esterification was analyzed. The reaction orders was 1.49; the activation energy Ea was 57.38 kJ/mol; the frequency factor A was 2.70 × 107; and the reaction kinetics model was -dcA/dt=2.70×107e-57.38RTcA1.49. The solidifying point (SP), cold filter plugging point (CFPP), and kinematic viscosity of isobutyl palmitate obtained were 3 °C, 7 °C, and 4.93 mm2 s−1, respectively. Compared to methyl palmitate, the SP decreased by six times, and CFPP decreased by 3.28 times. Therefore, the use of branched-chain alcohol instead of methanol ester exchange descaling method can effectively reduce the SP and CFPP of biodiesel to improve cold flow properties of biodiesel.

Winterization of biodiesel through progressive freezing for cold flow properties improvement

In cold environment, pure biodiesel cannot be used directly as an alternative fuel as it crystalizes easily at low temperature due to its saturated fatty acid (SFA) content. Thus, the winterization method is used to reduce the SFA content that gives high melting point to biodiesel. However, the conventional winterization method was reported to be complicated and ineffective in separating the liquid and solid content formed. Progressive freezing (PF) is introduced to improve the separation efficiency in the winterization process by removing the solid SFA layer formed on the wall of the crystallizer without the use of complicated equipment. In this study, the initial value of cloud point (CP) and pour point (PP) of the biodiesel were measured and compared with the values obtained after the PF process. The effect of coolant temperature, freezing time and stirring rate towards the efficiency of the PF process were also determined. The obtained results showed that the best performance of winterization was observed at coolant temperature of 6 °C, freezing time of 20 minutes and stirring rate of 50 rpm. At this condition, the recovery of biodiesel is 65.46% while CP, PP and SFA content were reduced by 2.65 %, 14.29 % and 3.96%, respectively.

Valorization of food-waste hydrolysate by Lentibacillus salarius NS12IITR for the production of branched chain fatty acid enriched lipid with potential application as a feedstock for improved biodiesel

Oxidation stability and cold flow properties of biodiesel can be improved by using lipid with enriched branched-chain fatty acid (BCFA) as a feedstock. A halophilic bacterium was utilized for the production of BCFA enriched lipid from acid hydrolysate of food-waste. The maximum reducing sugar obtained by hydrolysis of wheat bran, rice bran, mango peel, and orange peel were 64.52 ± 0.57, 38.7 ± 0.58, 55.64 ± 1.14, 36.29 ± 0.54 g/L, respectively. On assessing these hydrolysates as feedstock for growth of halophilic bacterium Lentibacillus salarius NS12IITR at 10 g/L reducing sugar concentration, wheat bran hydrolysate was found to be best in-terms of sugar consumption (92%), lipid production (0.70 ± 0.029 g/L) and maximum branched-chain fatty acid methyl ester (FAME) (81 ± 4.72% of total FAME). At 20 g/L of reducing sugar concentration of wheat bran hydrolysate, the biomass and lipid yields were almost doubled. Efficient lipid extraction from cell, involving thermolysis at 85 °C and pH 2 along with osmotic shock resulted in isolation of 69% of total lipid.

Conceptual design of production of eco-friendly polyoxymethylene dimethyl ethers catalyzed by acid functionalized ionic liquids

As the clean fuel additives, polyoxymethylene dimethyl ethers (DMMn) could significantly reduce carbonaceous particulate matters and volatile organic pollutants in the exhaust gas. Large scale production in a green route would be crucial if the DMMn tailored diesel was applied to the abatement of widespread PM air pollution. In the production, heavy components usually should be separated, recycled, decomposed and re-reacted to gain the aimed products, which would significantly increase complexity and energy consumption of the process. And fatally, it also might cause blockage of units and pipelines. In this work, to prevent blockage, the facile and robust process producing DMMn was conceptually designed basing on physicochemical properties researches. The process exempting from recycle of heavy components and de-heavy column was proposed according to cold-flow properties. Both energy consumption and fixed capital investment can be saved. The reaction kinetic model, which was described in the form of power law functions, showed good consistency for both propagation and depolymerization reactions. Flash points of diesel blends were also measured for determining specification of light components. This work shows it is feasible that DMMn can be produced from dimethoxy methane and trioxane in the presence of acid functionalized ionic liquids in large scale.

Proposing blends for improving the cold flow properties of ethylic biodiesel

Despite the several advantages compared to conventional diesel fuel, the biodiesel has poor cold flow properties, limitng its use as a fuel in moderate and cold climates. Considering that the fatty esters profile and the alcohol used affect the biodiesel physico-chemical behavior, this work explored the crystallization/melting profiles of ethyl biodiesel from different oil sources as well as of binary blends among them to improve their cold flow properties. Therefore, model ethyl biodiesels from soybean oil, beef tallow, palm oil, their fractions, olein and stearin, palm kernel, macauba, and macauba kernel oils were formulated by pure ethyl esters, their melting/crystallization temperature, cloud point, pour point, cold filter plugging point and the fraction of crystallized esters analysed. For all cases, blends decreased the cold flow properties of the heavier biodiesel. Soybean oil and tallow biodiesels, economically relevant sources, presented a CFPP of −4.28 °C and 17.12 °C, respectively, whilst some alternative sources, such as macauba and palm kernels biodiesels, presented values lower than −15 °C, which is more advantageous in cold climates. Tallow biodiesel was the only not in accordance with Regulation Agencies considering cold climates. Macauba and palm kernel oils were especially interesting to decrease the melting/crystallization temperatures of heavier biodiesels, including those from tallow beef. The best blend was those formulated with soybean and macauba kernel oils with a CFPP lower than −20 °C. This work suggested that not only biodiesels mainly composed by unsaturated esters but also by short-saturated esters could significantly improve the cold flow properties of high saturated biodiesel, being a low-cost and feasible alterative.

Ultrasonic Intensification To Produce Diester Biolubricants

Biolubricants synthesized from vegetable oils with oleic acid and 1,3-propanediol possess better cold flow properties and have a smaller environmental footprint than mineral-based lubricants. However, their synthesis is lengthy (>6 h) and requires temperatures above 120 °C. We applied ultrasound (US) to synthesize long-chain diesters (biolubricants): an ultrasonic horn delivered rated powers of 500 and 750 W at a frequency of 20 kHz to a solution of oleic acid and 1,3-propanediol. Amberlyst15-H esterified the acid to the diester biolubricant. US horns with powers of 750 and 500 W increased the reaction rate by factors of 2 and 1.2–1.5, respectively. A temperature of 100 °C is necessary to convert oleic acid to >50%. A partial factorial experimental design confirmed that temperature, US power, and initial molar ratio of reactants affect reaction rate and oleic acid conversion (p-value of <0.05). The 500 W horn is 17% less expensive than the 750 W horn.

Biobased Poly-phosphonate Additives from Methyl Linoleates

Poly-dialkyl phosphonates were synthesized by reacting methyl linoleate with dimethyl, diethyl, and di-n-butyl phosphites in the presence of free radical initiator and positively identified and characterized using gas chromatography–mass spectrometry (GC-MS), nuclear magnetic resonance (NMR; 1H, 13C, 31P), and Fourier transform infrared (FTIR). Neat poly-dialkyl phosphonates and their blends in high-oleic sunflower oil (HOSuO) and polyalphaolefin (PAO-6) base oils were investigated for their physical, chemical, and tribological properties. At room temperature, the poly-dialkyl phosphonates displayed much better solubility in HOSuO than in PAO-6. Solubility in the base oils increased in the order dimethyl < diethyl < di-n-butyl. Relative to methyl linoleate, the neat poly-dialkyl phosphonates displayed higher density, higher kinematic viscosity, higher oxidation stability, and better cold flow (lower pour point and cloud point) properties. As an additive (0–10% w/w) in HOSuO, increasing concentration of poly-di-n-butyl phosphonate resulted in increasing onset and peak oxidation temperatures and decreasing cloud point. Poly-di-n-butyl phosphonate blends in HOSuO also showed lower four-ball antiwear (AW) coefficient of friction (COF) and wear scar diameter (WSD) than corresponding blends with zinc dialkyl dithiophosphate (ZDDP). As an additive (0–10% w/w) in PAO-6 base oil, poly-di-n-butyl phosphonate displayed lower four-ball antiwear COF and comparable WSD relative to similar blends of ZDDP in PAO-6. The results indicate that poly-dialkyl phosphonates are promising biobased AW additives with comparable or better performance than current petroleum-based commercial AW additives such as ZDDP.

Integrated valorization of waste cooking oil and spent coffee grounds for biodiesel production: Blending with higher alcohols, FT–IR, TGA, DSC and NMR characterizations

This work deals for the first time with recycling a binary blend of waste cooking oil (WCO) and spent coffee grounds oil (SCGO) (50/50% by volume) into biodiesel. Additionally, this work aimed at valorizing both wastes while improving fatty acids composition to obtain a stabilized product due to low degree of unsaturation of SCGO besides, reducing its high acid value. Furthermore, blending with Euro diesel and higher alcohols of butanol, pentanol and hexanol to improve some biodiesel properties was investigated. Furthermore, FT–IR, UV–vis., TGA, DSC and NMR analyses to assess the blends quality was examined. Results have proved the advantage of pre-blending and higher alcohols addition to improve the fuel properties. The biodiesel exhibits excellent cetane number of 56.64, oxidation stability of about 6.51 h and iodine value of 83.71 (g iodine/100 g) due to the low degree of unsaturation (89.02). Blending with higher alcohols improves density and cold flow properties while keeping acceptable level of cetane number, flash point and higher heating value (HHV) rather than lower alcohols. Consequently, this opens new gates for biodiesel research area. In conclusion, this work reinforces that blending of WCO and SCGO improves biodiesel properties and add to the economy of this industry. Therefore, further examination on the blends effect in compression ignition diesel engines through engine emissions and combustion characteristics is recommended.

Polymer Additives as Cold Flow Improvers for Palm Oil Methyl Esters

Biodiesel is a fuel that can be originated from different raw materials. However, even a good quality biodiesel has its properties strongly dependent upon its fatty acid profile. For instance, samples with a high content of saturated fatty acids may present poor cold flow properties, meaning that they tend to solidify under low temperatures. In this work, we propose to synthesize polymer additives and apply them as cold flow improvers for palm methyl esters (biodiesel) and their blends with petrodiesel. The synthetic additives were evaluated at different concentrations to assess their effect on the pour point (PP) of the resulting neat or blended biofuel. By using 1000 ppm of poly(dodecyl acrylate‐co‐tetradecyl methacrylate), it was possible to decrease the PP of B5 (5 vol.% biodiesel + 95 vol.% diesel) and B20 (20 vol.% biodiesel + 80 vol.% diesel) to −35 °C and −14 °C, respectively, which allowed the use of these blends in regions where their flow properties would eventually be prohibitive. However, the performance of the additive on the neat fuel (B100) was negligible.

Improvement of cold flow properties of a new biofuel derived from glycerol

One of the barriers for the extended use of fatty acid methyl esters (FAME) as a diesel fuel component is the yield of raw glycerol as a by-product of the transesterification process. In fact, glycerol is considered as one of the most abundant waste feedstock in the world. A new fuel denoted as FAGE (Fatty Acid Glycerol formal Esters) produced from glycerol and waste oil has been developed. FAME is concomitantly obtained during the manufacturing process of FAGE in different proportions depending of the reaction conditions. Since FAGE cold flow properties are in disadvantage when compared to FAME, the influence of some cold-flow improvers in FAGE/FAME blends has been investigated. In this work, the use of some acetals, co-products of the FAGE production process, are proposed as cold-flow improvers, giving extra value to this new fuel since all the co-products obtained from the production process would have a new industrial use. These two acetals are GF (Glycerol Formal) and GFOMOM (Methoxy-methyl glycerol formal). The results obtained show that cold flow properties become poorer when the amount of FAGE increases in the FAGE/FAME blend, but such effect is very slight up to 50% FAGE. The use of the acetals improves cold flow properties of the blends up to 2 °C, with minor effect of the GF content in the GF/GFOMOM acetal blend. In addition, a commercial cold flow improver was tested, improving the pour point and the cold filter plugging point with only small effect on cloud point and crystallization temperature. The results obtained from the acetals and the cold flow improver are compared, and the value of the acetals as cold flow improvers has been proved. A combination of both, acetals and cold-flow improver, is proposed as an optimal method to improve cold flow properties.

Hydrodeoxygenation–Alkylation Pathway for the Synthesis of a Sustainable Lubricant Improver from Plant Oils and Lignin-Derived Phenols

Fatty acid methyl esters (FAMEs) derived from plant oils are excellent lubricant improvers, but they do not have desirable oxidative stability and cold-flow properties. This study investigated phenol hydrodeoxygenation in hexadecane and aromatic alkylation of FAMEs over a K30 montmorillonite catalyst to give phenyl-branched FAME (PBFAME) as a potential lubricant improver. The high selectivity to aromatic hydrocarbons during hydrodeoxygenation over Pd/C was likely due to the slow hydrogenation rate of phenols in hexadecane, absence of hydrogen bonding in nonpolar solvents allowing hydroxyl groups to participate in dehydration reactions, and limited diffusion of hydrogen from bulk solution to Pd sites. Isomers of methyl (methylphenyl)octadecanoate (n-MMPO) were produced during toluene alkylation of methyl oleate. The presence of both Brønsted and Lewis acid sites in K30 facilitated selective synthesis of n-MMPOs. The oxidative stability and cold-flow properties of n-MMPO were better than those of canola biodiesel.

The effect of bio-derived additives on fatty acid methyl esters for improved biodiesel cold flow properties

Biodiesel is a promising replacement for petroleum based diesel in a number of different applications. Although biodiesel offers numerous advantages over petrodiesel, one of its major disadvantages is its inferior cold flow properties. Additives are often added to biodiesel to remediate issues with cold flow and other problematic properties. This work explored the feasibility of using compounds derived from bio-based sources as an additive for biodiesel. Specifically, the additive’s efficacy in reducing the cloud point of model biodiesels was analyzed using differential scanning calorimetry. Each of the additives studied depressed the biodiesel cloud point, although most of the additives showed diminishing returns above a certain weight percent. For many of the additives, the mechanism of cloud point depression was found to be dilution. For these additives, their efficacy was hampered by self-association, a phenomenon confirmed by thermodynamic modeling. However, tripropionin and dimethyl azelate, molecules of similar size to the FAMEs in the biodiesel studied in this work, interfered with the development of a critical nucleus, causing more significant depressions in the cloud point. Overall, a thermodynamic model based on ideal solution theory was able to accurately predict cloud points for most mixtures studied. Large deviations were observed for systems with significant amounts of self-association and/or cocrystallization.

Lipid-based biofuel synthesized from palm-olein oil by supercritical ethyl acetate in fixed-bed reactor

This study aimed to investigate the effects of temperature, ethyl acetate to palm oil molar ratio, residence time, and packing alumina balls on triglyceride conversion, ethyl ester, and acetin contents. The complete triglyceride conversion was observed at 1.35 ± 0.05 times of the transition temperature. The packed alumina enhanced the ester content up to 20%; but it had no effect on the acetin content. Furthermore, this study also intended to determine the effects of the acetin content and thermal cracking on 19 fuel properties of lipid-based biofuel samples synthesized by supercritical ethyl acetate. The optimal condition was found at 380 °C, 20 MPa and ethyl acetate to oil molar ratio of 30:1. First, the density and kinematic viscosity of the biofuels were slightly higher than the maximum values specified by standards because of the presence of triacetin and polymerized products. Second, packing alumina balls increase the mixing intensity and thermal conductivity inside the tubular reactor resulted in higher contents of sulfated ash and carbon residue. Third, the acid values of the biofuel samples were considerably higher than the standard value of biodiesel. However, copper strip corrosion testing resulted in slight tarnishing (level 1A). The corrosiveness of fuels mainly originates from their sulfur compound content, neither biofuel sample was classified as a corrosive material. Furthermore, the high acid values of the samples interfered with the testing of oxidation stability. Finally, beneficial effects of triacetin on cold flow properties were revealed in this study. The cloud point and cold filter plugging point of lipid-based biofuels strongly depended on the thermal stress of the reaction conditions rather than the triacetin concentration.

Comparative analyses of biodiesel produced from jatropha and neem seed oil using a gas chromatography–mass spectroscopy technique

Biodiesel from jatropha, neem and cottonseed were produced and their compositions were analyzed using gas chromatography–mass spectroscopy. The results revealed that the jatropha, neem and cottonseed oils are reliable sources of biodiesel and are renewable, and hence have a potential to partially meet energy demands in an eco-friendly manner. The biodiesels produced from jatropha contained 91.97% methyl ester, and that produced from neem contained 70.2% methyl ester, whereas that produced from cotton contained 89.75% methyl ester.The greater proportion of prolific ester in the jatropha biodiesel is mono-saturated methyl octa-decanoate which contributes 53.44% by volume. This ester has the tendency of assigning stability to biodiesel. For neem-based biodiesel, the profile evaluation revealed that octadecanoic acid methyl ester is the dominant compound in the mixture with 54.69% by volume. For cotton, the profile revealed that the methyl octadecenoate (C19H36O2) is the predominant compound in the mixture, having the highest percentage of 17.72%. The physico-chemical analyses of the three biodiesels has indicated that the three conform with the American Society for Testing and Materials (ASTM) standards for specific gravity, viscosity, acid value, cold flow properties and sulfur content, and hence are suitable for use in compression ignition engines. Statistical analyses confirmed that there was no significant difference between the experimental values of all the physico-chemical properties investigated; therefore, the experimental data is validated.