Effects of blending alcohols with poultry fat methyl esters on cold flow properties

The low temperature operability, kinematic viscosity, and acid value of poultry fat methyl esters were improved with addition of ethanol, isopropanol, and butanol with increasing alcohol content. The flash point decreased and moisture content increased upon addition of alcohols to poultry fat methyl esters. The alcohol type did not result in a statistically significant difference in low temperature performance at similar blend ratios in poultry fat methyl esters. In addition, blends of ethanol in poultry fat methyl esters afforded the least viscous mixtures, whereas isopropanol and butanol blends were progressively more viscous, but still within specifications contained in ASTM D6751 and EN 14214. Blends of alcohols in poultry fat methyl esters resulted in failure of the flash point specifications found in ASTM D6751 and EN 14214. Flash points of butanol blends were superior to those of isopropanol and ethanol blends, with the 5 vol.% butanol blend exhibiting a flash point (57 °C) superior to that of No. 2 diesel fuel (52 °C). Blends of alcohols in poultry fat methyl esters resulted in an improvement in acid value with increasing content of alcohol. An increase in moisture content of biodiesel was observed with increasing alcohol content, with the effect being more pronounced in ethanol blends versus isopropanol and butanol blends. Finally, none of the alcohol–methyl ester samples exhibited a phase separation at sub-ambient temperatures.     

Influence of extended storage on fuel properties of methyl esters prepared from canola,palm, soybean and sunflower oils

Fatty acid methyl esters prepared from canola, palm, soybean, and sunflower oils by homogenous base-catalyzed methanolysis were stored for 12 months at three constant temperatures (? 15, 22, and 40 °C) and properties such as oxidative stability, acid value, kinematic viscosity, low temperature operability, and iodine value were periodically measured. Oxidative stability was significantly reduced upon extended storage and acid value as well as kinematic viscosity were increased by only small increments, with these effects more pronounced at elevated temperatures. Iodine value and low temperature operability were essentially unaffected by extended storage. Based on these findings, it is not recommended that acid value or kinematic viscosity be used as indicators of storage stability of biodiesel, nor is it recommended that iodine value be used as a predictor of oxidative stability or indicator of oxidative degradation.     

Effect of cold flow improvers on flow properties of soybean biodiesel

The influence of three cold flow improvers, namely, olefin-ester copolymers (OECP), ethylene vinyl acetate copolymer (EACP) and polymethyl acrylate (PMA), on the low-temperature properties and viscosity–temperature characteristics of a soybean biodiesel was evaluated on a low-temperature flow tester and a rotatory rheometer. The crystal morphologies of the biodiesel at low temperatures were investigated through a polarizing microscope. The results indicated that the ability of the cold flow improvers differed in improving the cold flow properties of soybean biodiesel, of which OECP was the best candidate. OECP can significantly reduce pour point (PP) and cold filter plugging point (CFPP) of biodiesel and retard viscosity increase of biodiesel at low temperatures when incorporated into biodiesel at the additive contents of 0.03%. On the other hand, OECP functioned by inhibiting the wax crystals from growing to a larger size and provided a barrier to crystal agglomeration at low temperatures, thus improving the cold flow properties of soybean biodiesel.     

Factors affecting the cold flow properties of biodiesel: Fatty acid esters

Biodiesel is renewable, sustainable, and cost-effective; it possesses good lubricity and high cetane number. Nevertheless, its poor cold flow properties impede the popularization and application of biodiesel. In this study, the cold flow properties of peanut and rapeseed biodiesel and their blends with different fatty acid esters were investigated, including different chain lengths (saturated and unsaturated), different double bond numbers, and different alcohol chains. Results showed that shorter chain length, more double bonds, and branched alcohol chain could effectively improve the biodiesel cold filter plugging point (CFPP). This study also tried to explore the mechanism action of this phenomenon.     

餐饮废油生物柴油低温流动性的改进研究

使用气-质联用仪测定餐饮废油生物柴油(WCME)和-10号柴油(-10PD)的组成,使用冷滤点试验器和运动黏度试验器测定WCME的低温流动性,同时使用调合、添加低温流动性改进剂的方法改进WCME的低温流动性。实验结果表明,WCME主要由饱和脂肪酸甲酯和不饱和脂肪酸甲酯组成,质量分数分别为27.63%和71.81%;WCME冷滤点为0℃,运动黏度(40℃)为4.41mm2/s;WCME与-10PD调合后,冷滤点降低,其中B20的冷滤点最低,为-13℃,运动黏度随着WCME的体积分数的减少,逐渐接近-10PD的运动黏度。通过添加低温流动性改进剂,WCME,B10,B20的冷滤点分别从0,-8,-13℃降至-4,-26,-25℃。     

Fuel properties and exhaust emissions of low blending rate soybean oil methyl esters blended with diesel fuel

The main properties and engine emissions of low blending rate soybean oil methyl ester blended with diesel from 5 to 30 wt% were compared and analyzed. The experimental results show that, compared with diesel fuel, with an increase in the soybean oil methyl ester percentage in the blends, distillation temperature at 50%, flash point, kinematic viscosity, specific gravity, gelatine content, carbon residue, acidity and ash increase while a cold filter plugging point, solidifying point and copper corrosion keep constant, sulfur content decreases, smoke density and HC decrease while NO_x emission increase, CO increases at 2,200 r/min but decreases at 3,400 r/min.     

Lipase immobilization and production of fatty acid methyl esters from canola oil using immobilized lipase

Lipase enzyme from Aspergillus oryzae (EC 3.1.1.3) was immobilized onto a micro porous polymeric matrix which contains aldehyde functional groups and methyl esters of long chain fatty acids (biodiesel) were synthesized by transesterification of crude canola oil using immobilized lipase. Micro porous polymeric matrix was synthesized from styrene-divinylbenzene (STY-DVB) copolymers by using high internal phase emulsion technique and two different lipases, Lipozyme TL-100L^® and Novozym 388^®, were used for immobilization by both physical adsorption and covalent attachment. Biodiesel production was carried out with semi-continuous operation. Methanol was added into the reactor by three successive additions of 1:4 M equivalent of methanol to avoid enzyme inhibition. The transesterification reaction conditions were as follows: oil/alcohol molar ratio 1:4; temperature 40 °C and total reaction time 6 h. Lipozyme TL-100L^® lipase provided the highest yield of fatty acid methyl esters as 92%. Operational stability was determined with immobilized lipase and it indicated that a small enzyme deactivation occurred after used repeatedly for 10 consecutive batches with each of 24 h. Since the process is yet effective and enzyme does not leak out from the polymer, the method can be proposed for industrial applications.     

Improving cold flow properties of canola-based biodiesel

Methods for improving the cold flow properties of canola-based biodiesel are described. Freezing point depression via dilution is evaluated through controlled studies of methyl stearate freezing in seven different solvents, and methyl palmitate in three solvents. Without accounting for solute activity, the Hildebrand equation can predict the impact of methyl stearate freezing point in an alkane solvent (pentane) to within 4 °C. However, there is wide deviation for the other solutions, indicating wide ranging solute activities in these solvents. Dilution in toluene results in the greatest freezing point depression. In addition, several polymeric additives are screened for their effectiveness as biodiesel pour point depressants. After examining more than 13 polymers, including several alkyl methacrylate homo- and copolymers, it is shown that poly(lauryl methacrylate) homopolymer most effectively improves the biodiesel cold flow properties. At 1% loading, poly(lauryl methacrylate) lowers the pour point by as much as 30 °C and the low temperature filterability point (LTFP) by as much as 28 °C. When evaluating the impact of polymer concentration, it is shown that poly(lauryl methacrylate) concentrations of 0.14% perform poorly, whereas 0.5% has only a slightly lower impact than 1%. Concentrations above 1% exhibit no improvement. Finally, it is shown that a limited amount of mixing can notably reduce the LTFP in several samples.     

Combustion and emission performances of coconut,palm and soybean methyl esters under reacting spray flame conditions

The spray combustion characteristics of coconut (CME), palm (PME) and soybean (SME) biodiesels/methyl esters were compared with diesel by using an axial swirl flame burner. Atomisation of the liquid fuels was achieved via an airblast-type nozzle with varied atomising air-to-liquid ratios (ALR) of 2–2.5. The fully developed sprays were mixed with strongly swirled air to form combustible mixtures prior to igniting at the burner outlet. Under fuel-lean condition, biodiesel spray flames exhibited bluish flame core without the yellowish sooty flame brush, indicating low sooting tendency as compared to baseline diesel. Increasing the atomising air led to the reduction of flame length but increase in flame intensity. Measurements of post-combustion emissions show that SME produced higher NO as compared to CME and PME due to higher degree of unsaturation, while the most saturated CME showed the lowest NO and CO emissions amongst the biodiesels tested across all equivalence ratios. By preheating the main swirl air to 250 °C, higher emissions of NO, CO and CO₂ were observed for biodiesels. Higher ALR led to reduced NO and CO emissions regardless of the fuel used, making it a viable strategy to resolve the simultaneous NOCO reduction conundrum. This work shows that despite different emission characteristics exhibited by biodiesels produced from different feedstock, they are in principle potential supplemental fuels for practical combustion systems. The pollutants emitted can be mitigated by operating at higher ALR in a twin-fluid based swirl combustor.     

Comparison of performance and emissions of diesel fuel,rapeseed and soybean oil methyl esters injected at different pressures

Fuel properties of rapeseed oil and soybean oil methyl esters (e.g. density, cetane number and viscosity etc.) are similar to those of the diesel fuel. These methyl esters can be used as diesel engine fuel by mixing withy diesel fuel. In this study a comparison of diesel fuel, the rapeseed oil methyl ester and the soybean oil methyl ester was made from the engine performance and emissions point of view. The tests were carried out with a four-cylinder diesel engine for tree different injection pressures such as 250, 300 and 350 bar with each of these fuels. For the purpose of comparison, tests were also conducted at full load conditions with diesel fuel. As the result, the performance and emission values of rapeseed oil (R) and soybean oil (S) methyl esters were found to be nearly the same with those of diesel fuels (D) when injection pressure was increased to 300 bar.     

Electrical properties of mixtures of fatty acid methyl esters from different vegetable oils

The dependence on temperature of the permittivity and conductivity of mixtures of Fatty Acid Methyl Esters (FAME) was determined between 300 K and 343 K, in the frequency range from 20 Hz to 2 MHz. Samples were made from oil of sunflower, corn, grape, chia, canola, jatropha, coconut and cottonseed.     

The effects of long-term storage on the cold flow properties and viscosity of canola-based biodiesel

In this study, the effects of long-term storage on the viscosity and cold flow properties of biodiesel were investigated. Canola oil with a high content of unsaturated fatty acid was used to produce biodiesel in the experiments. Biodiesel sample was kept in ordinary atmospheric storage conditions for 6 months. The samples were taken from the biodiesel feedstock in every 30 days and cold flow properties and kinematic viscosity of the samples were measured. During 6-month storage, no significant deterioration was observed in cold flow properties and kinematic viscosity of biodiesel. Additionally, the same pour point (PP) and cold filter plugging point (CFPP) values (?11°C) were obtained during this period.     

Net energy balance of small-scale on-farm biodiesel production from canola and soybean

One necessary criterion for a biofuel to be a sustainable alternative to the petroleum fuels it displaces is a positive net energy balance. This study estimated the net energy ratio (NER), net energy balance (NEB), and net energy yield (NEY) of small-scale on-farm production of canola [Brassica napus (L.)] and soybean [Glycine max (L.)] biodiesel in the upper Midwest. Direct and embodied energy inputs based on well-defined system boundaries and contemporary data were used to estimate the energy requirement of crop production, oil extraction, and biofuel processing. The NER of canola biodiesel was 1.78 compared with 2.05 for soybean biodiesel. Canola biodiesel had a NEB of 0.66 MJ MJ⁻¹ of biofuel compared with 0.81 MJ MJ⁻¹ for soybean biodiesel. The NEY of soybean biodiesel was 10,951 MJ ha⁻¹, less than canola biodiesel which had a NEY of 11,353 MJ ha⁻¹. Use of soybean as a biodiesel feedstock was more energetically efficient than canola primarily due to reduced nitrogen fertilizer requirement. In terms of energetic productivity, canola was a more productive biodiesel feedstock than soybean due to its higher oil content. A best-case scenario based on optimal feedstock yields, reduced fertilizer input, and advanced biofuel processing equipment suggested that potential gains in energetic efficiency was greater for canola than soybean. According to our results, small-scale on-farm biodiesel production using canola and soybean can be an energetically efficient way to produce energy for on-farm use.     

Fuel properties of Brassica juncea oil methyl esters blended with ultra-low sulfur diesel fuel

Brassica juncea is a drought-tolerant member of the Brassicaceae plant family with high oil content and a short growing season that is tolerant of low quality soils. It was investigated as a feedstock for production of biodiesel along with evaluation of subsequent fuel properties, both neat and in blends with petroleum diesel fuel. These results were compared against relevant fuel standards such as ASTM D6751, EN 14214, ASTM D975, EN 590, and ASTM D7467. Crude B. juncea oil was extracted from unconditioned seeds utilizing a continuous tubular radial expeller. The oil was then chemically refined via degumming, neutralization and bleaching to render it amenable to direct homogeneous sodium methoxide-catalyzed transesterification. The principal fatty acid detected in B. juncea oil was erucic acid (44.1%). The resulting biodiesel yielded fuel properties compliant with the biodiesel standards with the exception of oxidative stability and kinematic viscosity in the case of EN 14214. Addition of tert-butylhydroquinone and blending with soybean oil-derived biodiesel ameliorated these deficiencies. The fuel properties of B5 and B20 blends of B. juncea oil methyl esters (BJME) in ultra-low sulfur (<15 ppm S) diesel (ULSD) fuel were within the ranges specified in the petrodiesel standards ASTM D975, EN 590 and ASTM D7467 with the exception of derived cetane number in the case of EN 590. This deficiency was attributed to the inherently low cetane number of the certification-grade ULSD, as it did not contain performance-enhancing additives. In summary, this study reports new fuel property data for BJME along with properties of B5 and B20 blends in ULSD. Such results will be useful for the development of B. juncea as an alternative source of biodiesel fuel.     

Fuel properties of biodiesel from vegetable oils and oil mixtures. Influence of methyl esters distribution

In this work, the quality of biodiesel produced by basic transesterification from several vegetable oils (soybean, rapeseed, sunflower, high oleic sunflower, Cynara Cardunculus L., Brassica Carinata and Jatropha Curca) cultivated in Extremadura has been studied in detail. The influence of raw material composition on properties such as density, viscosity, cetane number, higher heating value, iodine and saponification values and cold filter plugging point has been verified. Other biodiesel properties such as acid value, water content and flash and combustion points were more dependent on characteristics of production process. Biodiesel produced by rapeseed, sunflower and high oleic sunflower oils transesterification have been biofuels with better properties according to Norm EN 14214. Finally, it has been tested that it is possible to use oils mixtures in biodiesel production in order to improve the biodiesel quality. In addition, with the same process conditions and knowing properties of biodiesel from pure oils; for biodiesel from oils mixtures, its methyl esters content, and therefore properties dependent this content can be predicted from a simple mathematical equation proposed in this work.     

Effects of minor constituents on cold flow properties and performance of biodiesel

Biodiesel is an alternative fuel or extender made from renewable agricultural lipids that may be burned in a compression-ignition (diesel) engine. It is defined as the mono-alkyl esters of fatty acids derived from plant oils or animal fats. Biodiesel has many important technical advantages compared to petrodiesel including superior inherent lubricity, low toxicity, high (non-flammable) flash point and biodegradability, very low or negligible sulfur content and lower exhaust emissions of most regulated species. Biodiesel is generally produced by transesterification of the lipid with a short-chain monohydric alcohol. This process may leave behind very small (trace) concentrations of minor constituents such as saturated monoacylglycerols (MAGs) or free steryl glucosides (FStGs). These materials have high melting points and very low solubilities allowing them to form solid residues when stored during cold weather. Blending with petrodiesel exacerbates the problem. Settling solid residues were found to clog fuel filters in fuel dispensers and vehicles. In response to documented problems the biodiesel industry in the United States collaborated with the American Society of Testing and Materials (ASTM) to develop a cold soak filterability performance test that will help identify fuels that may have a propensity to clog filters if exposed to long-term storage in cold weather.     

Ethyl levulinate: A potential bio-based diluent for biodiesel which improves cold flow properties

Biodiesel, defined as mono-alkyl esters of long-chain fatty acids derived from vegetable oils or animal fats, is an attractive renewable fuel alternative to conventional petroleum diesel fuel. Biodiesel produced from oils such as cottonseed oil and poultry fats suffer from extremely poor cold flow properties because of their high saturated fatty acid content. In the current study, Ethyl Levulinate (ethyl 4-oxopentanoate) was investigated as a novel, bio-based cold flow improver for use in biodiesel fuels. The cloud (CP), pour (PP), and cold filter plugging points (CFPP) of biodiesel fuels prepared from cottonseed oil and poultry fat were improved upon addition of ethyl levulinate at 2.5, 5.0, 10.0, and 20.0% (vol). Reductions of 4-5 °C in CP, 3-4 °C in PP and 3 °C in CFPP were observed at 20 vol % ethyl levulinate. The influence of ethyl levulinate on acid value, induction period, kinematic viscosity and flash point was determined. The kinematic viscosities and flash points decreased with increasing content of ethyl levulinate. All samples (≤15 vol % ethyl levulinate) satisfied the ASTM D6751 limit with respect to flash point, but none of the 20 vol % blends were acceptable when compared to the higher EN 14214 specification. Acid value and oxidative stability were essentially unchanged upon addition of ethyl levulinate. In summary, ethyl levulinate appears acceptable as a diluent for biodiesel fuels with high saturated fatty acid content.     

Fatty acid methyl esters (FAMEs) from castor oil: Production process assessment and synergistic effects in its properties

Fatty acid methyl esters (FAMEs) from castor oil have been synthesized by methanolysis catalyzed by sodium methoxide and the optimal transesterification conditions have been found. However, some properties of the castor FAME render it unsuitable in pure state for its direct use as fuel in internal combustion engines. Thus, blends with reference diesel have been prepared and their properties have been evaluated. Among these properties, the oxidative stability of the blends shows a negative anti-synergistic effect, that is, all the blends have an induction period lower than the pure reference diesel and the pure castor FAME. On the contrary, the lubricity shows a positive synergistic effect, the wear scar of the blends being always lower than those of the pure components. The cold-filter plugging point of the blends shows also a singular effect, since the filterability remains identical to that of the reference diesel until around 50 vol% of castor FAME has been blended with it. The blends of castor FAME and reference diesel until approximately 40 vol% of castor FAME meet most of the specifications of the EN 590 standard.     

棕榈油生物柴油低温流动性的改进及其对氧化稳定性的影响

文章对棕榈油生物柴油的低温流动性和氧化稳定性进行了分析,发现棕榈油生物柴油具有较好的氧化稳定性,但是低温流动性较差。通过不同的方法(与-10#柴油、油酸甲酯、菜籽油生物柴油按照不同体积比混合)对棕榈油生物柴油的低温流动性进行了改进,并利用流变仪和Rancimat法分析了改进方法对棕榈油生物柴油低温流动性及氧化稳定性的影响。研究结果表明:与油酸甲酯混合可以降低棕榈油生物柴油的胶凝点,但其氧化稳定性随之变差;当棕榈油生物柴油的体积含量为5%~20%时,与-10#柴油的混合使得油样的胶凝点低于-10℃,氧化诱导期大于20 h;当棕榈油生物柴油的体积含量低于40%时,与菜籽油生物柴油的混合使得油样的胶凝点低于0℃,氧化诱导期大于6 h。     

Combined impact of varying biogas mass flow rate and rice bran methyl esters blended with diesel on a dual-fuel engine

ABSTRACT

For fetching day-to-day energy needs, current energy requirement majorly depends on fossil fuels. But ambiguous matter like abating petroleum products and expanding air pollution has enforced the experts to strive for another fuel which can be used as an alternative or reduce the applications of fossil fuels. Considering the issues, the main objective of the present study is to find the feasibility by using blends of rice bran oil biodiesel and diesel which are used as pilot fuels by blending 10% and 20% biodiesel in fossil diesel and biogas, introduced as gaseous fuel by varying its mass flow rate in a dual-fuel engine mode. An experimentation study was carried out to find the performance and emission parameters of the engine relative to pure diesel. The results were very much similar to the majority of researchers who used biodiesel and gaseous fuels in a dual-fuel engine. Brake specific fuel consumption (BSFC) of the engine was noticed to have increased, while brake thermal efficiency was on the lower side in dual fuel mode in comparison with regular diesel. In relation with conventional diesel, it was noticed that combined effect of rice bran methyl esters and varying mass flow rate of biogas showed a decrement in NO _x and smoke emissions, whereas HC and CO exhalations were on higher side when biogas and biodiesel were utilized collectively in dual-fuel engine. Hence, it was concluded that combination of blends of biodiesel and diesel and introduction of biogas in the engine can be a promising combination which can be used as a substitute fuel for addressing future energy needs.