Fuel properties and emissions of soybean oil esters as diesel fuel

The effects of using blends of methyl and isopropyl esters of soybean oil with No. 2 diesel fuel were studied at several steady-state operating conditions in a four-cylinder turbocharged diesel engine. Fuel blends that contained 20, 50, and 70% methyl soyate and 20 and 50% isopropyl soyate were tested. Fuel properties, such as cetane number, also were investigated. Both methyl and isopropyl esters provided significant reductions in particulate emissions compared with No. 2 diesel fuel. A blend of 50% methyl ester and 50% No. 2 diesel fuel provided a reduction of 37% in the carbon portion of the particulates and 25% in the total particulates. The 50% blend of isopropyl ester and 50% No. 2 diesel fuel gave a 55% reduction in carbon and a 28% reduction in total particulate emissions. Emissions of carbon monoxide and unburned hydrocarbons also were reduced significantly. Oxides of nitrogen increased by 12%.     

Exhaust emissions and fuel properties of partially hydrogenated soybean oil methyl esters blended with ultra low sulfur diesel fuel

Important fuel properties and emission characteristics of blends (20 vol.%) of soybean oil methyl esters (SME) and partially hydrogenated SME (PHSME) in ultra low sulfur diesel fuel (ULSD) were determined and compared with neat ULSD. The following changes were observed for B20 blends of SME and PHSME versus neat ULSD: improved lubricity, higher kinematic viscosity and cetane number, lower sulfur content, and inferior low-temperature properties and oxidative stability. With respect to exhaust emissions, B20 blends of PHSME and SME exhibited lower PM and CO emissions in comparison to those of neat ULSD. The PHSME blend also showed a significant reduction in THC emissions. Both SME and PHSME B20 blends yielded small increases in NO_x emissions. The reduction in double bond content of PHSME did not result in a statistically significant difference in NO_x emissions versus SME at the B20 blend level. The test engine consumed a greater amount of fuel operating on the SME and PHSME blends than on neat ULSD, but the increase was smaller for the PHSME blend.     

Combustion characteristics of fatty acid methyl esters derived from recycled cooking oil

The goal of this study is to find out the exhaust emissions differences produced by different kinds of fatty acid methyl esters (FAME) derived from used cooking oils and animal fats, as well as the importance of the purification step in exhaust emissions production. A total of 120 L of waste vegetable oil and 30 L of waste frying oil were collected and converted into three batches of FAME. There were two batches of FAME produced from waste vegetable oil (B01 and B02), and one batch of FAME produced by mixing 2% of waste frying oil with waste vegetable oil (B03). The FAMEs used in this study had higher density, kinematic viscosity, and flash point, but a lower gross heating value, when compared to the premium diesel. The B01 engine produced higher CO formation and the diesel-fuelled engine produced higher CO than the B02 and B03 did for engine speeds higher than 1400 rpm. Most of the FAME fuels produced higher CO₂ than the diesel fuel did. The FAME fuels emitted higher NO_x and PM, but lower SO₂, than the diesel fuel. C_nH_2n+2, diphenyl sulfone (C₁₂H₁₀O₂S), and diethyl phthalate (C₁₂H₁₄O₄) can be selected as the character index for the combustion of FAME.     

Analysis of epoxidized soybean oil by gas chromatography

A fast and cost-effective procedure to quantitate epoxidized soybean oil by means of an external standard method is reported. This procedure is applicable to commercial epoxidized oils, polymer additive packages and polymers—polyvinyl chloride (PVC)—containing epoxidized oils. The epoxidized soybean oil is converted into fatty acid methyl esters with tetramethylammonium hydroxide, and analyzed by capillary gas chromatography with flame-ionization detection. In PVC samples, the epoxidized soybean oil was extracted with toluene and followed by derivatization prior to analysis. The methyl esters of monoepoxyoctadecanoic, diepoxyoctadecanoic and triepoxyoctadecanoic acid were separated with a short capillary column.     

Low-temperature properties of triglyceride-based diesel fuels: Transesterified methyl esters and petroleum middle distillate/ester blends

This work examines low-temperature properties of triglyceride-based alternate fuels for direct-injection compression-ignition engines. Methyl esters from transesterified soybean oil were studied as neat fuels and in blends with petroleum middle distillates (No. 1 or No. 2 diesel fuel). Admixed methyl esters composed of 5–30 vol% tallowate methyl esters in soyate methyl esters were also examined. Pour points, cloud points, and kinematic viscosities were measured; viscosities at cooler temperatures were studied to evaluate effects of sustained exposure. Low-temperature filterability studies were conducted in accordance with two standard methodologies. The North American standard was the low-temperature flow test (LTFT), and its European equivalent was the cold-filter plugging point (CFPP). With respect to cold-flow properties, blending methyl esters with middle distillates is limited to relatively low ester contents before the properties become preclusive. Under most conditions, cold-flow properties were not greatly affected by admixing the methyl esters with up to 30 vol% tallowate (before blending). Least squares analysis showed that both LTFT and CFPP of formulations containing at least 10 vol% methyl esters are linear functions of cloud point. In addition, statistical analysis of the LTFT data showed a strong 1:1 correlation between LTFT and CP. This result may prove crucial in efforts to improve low-temperature flow properties of alternate diesel fuels that contain methyl esters derived from triglycerides.     

Interesterification of tallow and sunflower oil

The objective of this study was to manufacture a shortening using chemical interesterification (IT) of tallow-sunflower oil blends to replace fish oil in the present formulation, which is now in short supply in Chile. The significant variables of the IT process were obtained by 2⁴⁻¹ fractional factorial design. The proportion of tallow (T) in the blend, catalyst concentration, and reaction temperature had a significant effect on the melting point (mp) (P≤0.05). IT of tallow and sunflower oil blends (90∶10 and 70∶30) diminished the mp, dropping point, and refractive index compared to tallow. However, a noninteresterified 90∶10 blend mp was not significantly different from tallow. IT produced a solid fat content (SFC) profile of IT90∶10 blend that was appropriate for use in shortenings for the baking industry. Blending and IT of the 90∶10 blend increased the melting profile of the tallow and the melting range from −40 to 60°C while the endotherms of the middle-melting triacylglycerols (TAG) decreased. The IT90∶10 blend hardnesswas 70% lower than tallow hardness, and the crystal network was composed of large spherulites in a network. IT resulted in an appropriate method to improve physical properties of tallow, whereas blending did not significantly modify it. The interesterification changed the SFC profile of IT90∶10, giving a more appropriate shortening for use in the baking industry.     

相转移催化大豆油醇解研究

通过催化大豆油与甲醇进行酯交换反应合成脂肪酸甲酯(FAME),研究了相转移催化剂对油脂醇解的催化性能。考察了不同醇油摩尔比、催化剂用量、反应时间和反应温度对大豆油醇解反应的影响,得到了较佳工艺条件:n(甲醇)∶n(大豆油)为6∶1,催化剂用量为大豆油质量的1.0%,35℃~40℃下反应1 h。结果表明:苄基三乙基氢氧化铵是油脂醇解的有效催化剂,在优化工艺条件下甲酯产率达91%以上。     

Separation of fatty acid methyl esters from tall oil by selective adsorption

Fatty acid methyl esters (FAME) and resin acids (RA) were separated from tall oil by selective adsorption. Commercial nonmodified molecular sieve 13X was used as adsorbent. The adsorption isotherms of fatty acids (FA), FAME, and RA on molecular sieve 13X at 25°C were determined using various solvents. The solvents were methanol, ethanol, isopropanol, acetone, benzene, hexane, isooctane, petroleum ether (40–60°C), and petroleum naphtha (80–180°C). With each solvent, FA and RA were adsorbed to a greater extent than FAME. Adsorption isotherms for RA and FAME in binary adsorption systems were also determined using petroleum ether, petroleum naphtha, benzene, and isopropanol. For each component in the binary adsorption, the equilibrium amounts are lower than the values for pure component adsorption. The adsorption of FAME decreased in the presence of RA markedly in petroleum ether and petroleum naphtha. This fact may be the indication of the phenomenon of selective adsorption. Separation was accomplished by adding a solution of esterified tall oil in solvents used in the binary adsorption systems, through a column packed with molecular sieve 13X. With petroleum naphtha, FAME and RA were recovered in yields of 93 and 94%, respectively, from esterified tall oil. Petroleum naphtha gave the best results. The effects of particle size of adsorbent and flow rate of solvent on the efficiency of the separation were also investigated in fixed-bed column studies. The particle size of adsorbent did not apparently alter the results. Changes in the particle size should not significantly change the number of available adsorption sites in a microporous molecular sieve.     

Improvement of fuel properties of cottonseed oil methyl esters with commercial additives

The low temperature operability and oxidative stability of cottonseed oil methyl esters (CSME) were improved with four anti‐gel additives as well as one antioxidant additive, gossypol. Low temperature operability and oxidative stability of CSME was determined by cloud point (CP), pour point (PP), cold filter plugging point (CFPP), and oxidative stability index (OSI). The most significant reductions in CP, PP, and CFPP in all cases were obtained with Technol®, with the average reduction in temperature found to be 3.9 °C. Gunk®, Heet®, and Howe's® were progressively less effective, as indicated by average reductions in temperature of 3.4, 3.0, and 2.8 °C, respectively. In all cases, the magnitude of CFPP reduction was greater than for PP and especially CP. Addition of gossypol, a polyphenolic aldehyde, resulted in linear improvement in OSI (R² = 0.9804). The OSI of CSME increased from 5.0 to 8.3 h with gossypol at a concentration of 1000 ppm.     

豆油制备不饱和聚酯树脂性能研究

以可再生资源豆油、丙三醇为原料醇解制备了单甘酯,将其作为二元醇,部分取代丙二醇与酸酐反应制得不饱和聚酯树脂(UP)。采用DSC,DMA以及力学性能测试等手段研究了单甘酯含量对豆油不饱和聚酯树脂性能的影响。结果表明,随着单甘酯含量的增加,豆油不饱和聚酯树脂的固化放热峰值降低、固化收缩率减小;存储模量和玻璃化转变温度都有一定程度降低,弯曲强度和拉伸强度也逐渐下降;冲击强度和拉伸断裂伸长率增高(单甘酯质量分数为40%时可分别达到102.074 kJ/m2和27.69%)。该方法制备的UP树脂成本低廉,柔韧性好,可满足一般的使用要求。     

Mechanical and rheological properties of epoxidized soybean oil plasticized poly(lactic acid)

Poly(lactic acid) (PLA) is a well known biodegradable thermoplastic with excellent mechanical properties that is a product from renewable resources. However, the brittleness of PLA limits its general applications. Using epoxidized soybean oil (ESO) as a novel plasticizer of poly(lactic acid), the composite blend with the twin‐screw plastic extruder at five concentrations, 3, 6, 9, 12, and 15 wt %, respectively. Compared with pure PLA, all sets of blends show certain improvement of toughness to different extents. The concentration with 9 wt % ESO increases the elongation at break about 63%. The melt flow rates of these blends with respect to different ESO ratio have been examined using a melt flow indexer. Rheological behaviors about shear viscosity and melt strength analysis are discussed based on capillary rheology measurements. The tensile strength and melt strength of the blends with 6 wt % ESO simultaneity reach the maximums; whereas the elongation at break of the blends is the second highest level. ESO exhibits positive effect on both the elongation at break and melt strength. The results indicate that the blend obtained better rheological performance and melt strength. The content of 6 wt % ESO in PLA has been considered as a better balance of performance. The results have also demonstrated that there is a certain correlation between the performance in mechanical properties and melt rheological characterization for the PLA/ESO blends.© 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Oxidative stability of soybean oil products obtained by regioselective chemical interesterification

Oxidative stability of products produced as potential margarine basestock from soybean oil and methyl stearate by a novel chemical regioselective interesterification was evaluated. The oxidative stability of the products was evaluated by peroxide formation and volatile analysis during storage in the dark with oxygen at 60°C for 72 h. The product obtained by regioselective interesterification resulted in the lowest peroxide formation and volatile concentration sample in comparison with soybean oil and the randomized product of the regioselective interesterified product. Regioselective interesterification of soybean oil with methyl stearate produced a product with increased oxidative stability. Presented at 84th American Oil Chemists’ Society Annual Meeting, April 26–30, 1993, Anaheim, California.     

Toughening polylactide by direct blending of cellulose nanocrystals and epoxidized soybean oil

Polylactide (PLA) is a bio-based polymeric material which is earth abundant in nature. It also possesses abundant strength and stiffness making it a promising material for industrial applications. However, its brittle behavior is currently limiting research work on them. As such, an eco-friendly blending approach is developed in this study in order to fabricate a ductile and toughen PLA composites using renewable bio-based materials as a precursor. Specifically, PLA, epoxidized soybean oil (ESO), and frangible powder form of cellulose nanocrystals (CNCs) are melt blended to prepare the ternary composite system (PLA/CNC/ESO). During the composite routing, it is found out that the ESO successfully attached to the surface of CNC which in turn results in CNC/ESO mixtures in the PLA matrix. This intrinsic combination induces cavitation which consumes the energy produced under the stretching and impacting, resulting in the turning of the PLA's brittle phenomenon. In fact, a reasonable increase in the ductility is observed. The elongation and notched impact strength of the ternary nanocomposite are found to be ∼32% and ∼4.8 kJ m⁻², respectively, which are comparatively higher than that of neat PLA or PLA/CNC composites. Differential scanning calorimetry analyses show that the ESO layer on CNC affects the thermal characteristics of PLA in the ternary composite while thermogravimetric analysis shows that there is an increase in the char yield of the composite. Furthermore, scanning electron microscopy analysis shows that the synthesis approach adopted here enables a mechanistically turning of the PLA's brittle phenomenon to ductile. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48221.     

Relationship between oil binding capacity and physical properties of interesterified soybean oil

The objective of this study was to identify the physical properties of an interesterified soybean oil (EIESOY), containing 45% saturated fatty acids (SFA), that correlates with high oil binding capacity (OBC) and low oil loss (OL). In this study, three EIESOY samples were analyzed; a 100% sample, a 50% sample diluted with 50% soybean oil, and a 20% sample diluted with 80% soybean oil. All samples were crystallized using fast (7.78°C/min) and slow (0.1°C/min) cooling rates as well as with and without high-intensity ultrasound (HIU, 20 kHz). The 100%, 50%, and 20% samples were crystallized at 38.5, 27.0, and 22.0°C, respectively. HIU was applied at the onset of crystallization and all samples were allowed to crystallize isothermally for 90 min. After 90 min, physical properties such as crystal microstructure, hardness, solid fat content (SFC), elasticity, and melting behavior were evaluated. Physical properties were also measured after storage for 48 h at 22 and 5°C. Results show that OBC was positively correlated with hardness, G′, and SFC after 48 h (r = 0.738, p = 0.006; r = 0.639, p = 0.025; r = 0.695, p = 0.012; respectively), OL was negatively correlated with hardness after 48 h (r = −0.696, p < 0.001), G′ after 90 min and 48 h (r = −0.704, p < 0.001; r = −0.590, p = 0.002), and SFC after 90 min and 48 h (r = −0.722, p < 0.001; r = −0.788, p < 0.001). Neither OBC nor OL were correlated with crystal diameter or the number of crystals.     

Low-temperature properties of alkyl esters of tallow and grease

The low-temperature properties of mono-alkyl esters derived from tallow and recycled greases were determined for neat esters and 20% ester blends in No. 2 low-sulfur diesel fuel. Properties studied included cloud point, pour point, cold filter plugging point, low-temperature flow test, crystallization onset temperature, and kinematic viscosity. Compositional properties of the alkyl esters determined included water, residual free fatty acids, and free glycerol content. In general, the secondary alkyl esters of tallow showed significantly improved cold-temperature properties over the normal tallow alkyl ester derivatives. The low-temperature flow test did not show a 1:1 correlation with cloud point as previously observed with methyl soyate and methyl tallowate. For the homologous series methyl to n-butyl tallowate, ethyl tallowate had the best broad-spectrum low-temperature properties, both neat and when blended in diesel fuel. For the greases studied, both the normal and branched alkyl ester derivatives showed improved properties over corresponding tallow esters, especially with neat esters.     

In-situ alcoholysis of soybean oil

In-situ alcoholysis of soybean oil with methanol, ethanol,n-propanol, andn-butanol was investigated, as well as the extraction of the oil with these solvents, to explain the progress ofin-situ alcoholysis and to determine the parameters that affect this reaction. Because methanol is a poor solvent for soybean oil, the amount of oil dissolved in methanol and converted to methyl esters was low afterin-situ alcoholysis. Ethyl, propyl, and butyl esters of soybean fatty acids could be obtained in high yields fromin-situ alcoholysis of soybean oil with these alcohols.In-situ alcoholysis proceeded through dissolution and alcoholysis of triglycerides successively, and the overall reaction rate was determined by the extraction and alcoholysis rates. The parameters, affecting yield and purity of the product esters, were mainly those that favor extraction rate.     

大豆油与甲醇酯交换反应体系的相平衡研究

生物柴油是一类清洁的可再生液体燃料,精炼植物油与甲醇酯交换是制备生物柴油的重要反应。针对目前难以准确获得酯交换反应体系的多组分相平衡组成等方面存在的问题,研究了间歇反应和连续逆流分离甘油等不同反应方式下大豆油与甲醇酯交换反应体系的多组分相平衡行为,并以三油酸甘油酯与甲醇酯交换为模型反应,采用UNIFAC和Modified UNIFAC模型进行了模拟计算。结果表明,在常压、60^oC反应条件下,在总组成偏离甲醇-甲酯二元组成的区域,UNIFAC和Modified UNIFAC模型准确计算了生物柴油酯交换反应体系的三元和四元相平衡组成。在甘油含量大于2.2%(质量)或转化率小于90%(质量)的酯交换反应中,计算值与实验值的平均偏差约为2%。酯交换反应相平衡的实验值和模型计算值表明,采用连续逆流方式分离甘油可以提高酯相中的甲醇含量,有利于传质和酯交换反应。这些结果为生物柴油工艺过程模拟、设备优化以及新技术开发提供了理论参考。     

Hydrogenation of oxidized soybean oil

Anderson Clayton Foods, Richardson, TX 75080 Portions of refined and bleached soybean oil were stored at various temperatures for various lengths of time, then hydrogenated to 70 iodine value (IV) to find the effect of peroxides on the rate of hydrogenation and on characteristics of hydrogenated product. Samples were treated up to 3 wk at up to 65°C and provided samples with peroxide values (PV) of up to 358. All samples were analyzed, hydrogenated, and reanalyzed. Peroxides affected the fatty acid composition as determined by gas chromatography, the calculated iodine value based on fatty acid composition, and rate of hydrogenation. Peroxides also affected the selectivity of hydrogenation and slope of the solids curve in hydrogenated products.     

Preparation and properties of zeroTrans soybean oil margarines

Experimental margarines were prepared in the pilot plant from interesterified soybean oil-soybean trisaturate blends and compared to a product made from hydrogenated soybean oil. Penetration, yield values, and water/oil off-data were determined. Margarine prepared from an interesterified soy-soy trisaturate blend (80:20) tended to crystallize slowly after votation and resulted in a somewhat harder than desirable product. However, addition of 20% liquid soybean oil to the interesterified oil yielded a softer product. The experimental products showed excellent oil and water loss properties under accelerated storage conditions.