高酸价油脂制备生物柴油的研究

以高游离脂肪酸含量的大豆酸化油为原料,在较高的压力和温度条件下,经催化甲酯化制备生物柴油,研究了甲酯化的优化反应条件并在此条件下对大豆酸化油、菜籽酸化油、地沟油的甲酯化效率进行了验证试验。结果表明在醇油质量比1:1.25,催化剂NaA/MgR用量为油质量的 1%,压力 3.0 MPa,温度 188℃,反应时间 120 min,3种原料油脂总脂肪酸甲酯含量达到 95%,生物柴油得率在 94% 左右。所得生物柴油产品质量指标符合ASTM 6751-03a的质量指标,且本工艺可以实现工业化。     

BrΦnsted酸离子液体催化废油脂制备生物柴油

采用磺酸类BrΦnsted酸离子液体作为催化剂,研究了不同工艺条件下催化废油脂制备生物柴油的过程. 以地沟油为原料,醇/油摩尔比12:1,催化剂用量为油质量的2%,在140℃下反应5 h,产物中脂肪酸甲酯的含量达到86.8%. 在同样的反应条件下,催化剂重复使用9次后其活性无明显变化. 该催化剂对废油脂制备生物柴油具有较高的催化活性和良好的重复使用性能.     

Fe3O4/Nafion-H磁性核壳纳米超强酸材料催化地沟油制备生物柴油研究

首先制备了纳米Fe3O4磁性材料,然后将固体超强酸全氟磺酸树脂(Nafion-H)包覆于纳米磁性材料上制备了磁性核壳纳米超强酸Fe3O4/Nafion-H材料,并将其应用于催化地沟油制备生物柴油,对醇油配料比、反应温度、反应时间和催化剂用量等工艺条件进行了优化。研究发现,在醇油质量比为1、反应温度为55℃、催化剂用量为1 mg/g、反应时间为3 h时,生物柴油的产率可达98%,其各项指标均符合甚至优于生物柴油的国家标准。     

Brфnsted酸离子液体催化废油脂制备生物柴油

采用磺酸类Br?nsted酸离子液体作为催化剂，研究了不同工艺条件下催化废油脂制备生物柴油的过程. 以地沟油为原料，醇/油摩尔比12:1，催化剂用量为油质量的2%，在140℃下反应5 h，产物中脂肪酸甲酯的含量达到86.8%. 在同样的反应条件下，催化剂重复使用9次后其活性无明显变化. 该催化剂对废油脂制备生物柴油具有较高的催化活性和良好的重复使用性能.     

黄连木油脂基生物柴油的合成及其性能分析

以黄连木油脂为原料,对预酯化和酯交换两步法制备生物柴油的工艺进行了研究.通过正交实验,得出预酯化最佳工艺条件为:醇油摩尔比8∶1、催化剂加入量为0.8%、反应时间为3 h;酯交换最优工艺为:催化剂用量为0.6%、醇油摩尔比6∶1、反应时间为2 h、反应温度为50℃;此条件下制备的生物柴油得率达到92.3%;通过二聚化反应,所得生物柴油的主要性能指标均达到了国家标准GB/T 20828-2007.     

无溶剂体系中酶法催化微藻油脂乙酯化制备生物柴油工艺研究

研究了无溶剂体系中酶法催化微藻油脂乙酯化制备生物柴油的技术工艺,采用Box-Behnken设计及响应面优化了工艺参数。经SAS 9.2软件分析得到的最优条件为:Novozym 435脂肪酶用量6.0%(w/w),醇油摩尔比4.0∶1,温度44.7℃,反应时间17.6 h。在该条件下,乙酯得率达94.86%。同时,获得的较高乙酯转化率为微藻油脂中多不饱和脂肪酸提取奠定了技术基础。     

无溶剂体系中酶法催化微藻油脂乙酯化制备生物柴油工艺研究

研究了无溶剂体系中酶法催化微藻油脂乙酯化制备生物柴油的技术工艺,采用Box-Behnken设计及响应面优化了工艺参数。经SAS 9.2软件分析得到的最优条件为:Novozym 435脂肪酶用量6.0%(w/w),醇油摩尔比4.0∶1,温度44.7℃,反应时间17.6 h。在该条件下,乙酯得率达94.86%。同时,获得的较高乙酯转化率为微藻油脂中多不饱和脂肪酸提取奠定了技术基础。     

改性4A分子筛催化高酸值油脂制备生物柴油

以浓硫酸为改性剂,采用化学键合方法对固体分子筛4A表面进行磺化改性。以此为催化剂催化油酸-菜籽油模拟的高酸值油脂-甲醇酯交换反应制备生物柴油。结果表明,反应体系在65℃,醇/油摩尔比为16∶1条件下反应6h,生物柴油产率可达到88.39%,比相同条件下未改性的分子筛4A和浓硫酸催化高酸油脂制备的生物柴油产率明显提高。     

负载型固体酸催化合成生物柴油

以固体酸TSOH/HY-SBA-15（对甲苯磺酸改性的介孔分子筛）为催化剂,催化大豆油和甲醇制备生物柴油,考察了反应的最适宜条件。结果表明,催化剂为(0.5 mol/L)TSOH/(10 %)HY-SBA-15,反应温度为180 ℃,反应时间为7 h,n(醇)/n(油)为25,催化剂用量为油质量的5 %,溶剂用量为油质量的30 %,生物柴油的收率可达到94.6 %。     

高酸值废弃油脂甘油酯化脱酸研究

无催化条件下,开展甘油对高酸值废弃油脂酯化脱酸研究,优化酯化反应最佳工艺参数;并对酯化脱酸后油脂经酯交换制备的生物柴油产品质量进行指标检测。研究表明,甘油无催化酯化脱酸的最佳工艺条件:甘油添加量为150%、反应温度为220℃、反应时间8 h、真空度为0.03 MPa,可将酸化油的酸值降至2.1 mg KOH/g,满足酯交换制备生物柴油原料酸值的要求;制备生物柴油产品质量指标符合国家现行生物柴油标准,为产业化、连续化和规模化的生产应用提供理论依据和参数指导。     

Biodiesel Production from Soybean Oil Catalyzed by Li<Subscript>2</Subscript>CO<Subscript>3</Subscript>

In the present study, we synthesized biodiesel from soybean oil through a transesterification reaction catalyzed by lithium carbonate. Under the optimal reaction conditions of methanol/oil molar ratio 32:1, 12 % (wt/wt oil) catalyst amount, and a reaction temperature of 65 °C for 2 h, there was a 97.2 % conversion to biodiesel from soybean oil. The present study also evaluated the effects of methanol/oil ratio, catalyst amount, and reaction time on conversion. The catalytic activity of solid base catalysts was insensitive to exposure to air prior to use in the transesterification reaction. Results from ICP-OES exhibited non-significant leaching of the Li₂CO₃ active species into the reaction medium, and reusability of the catalyst was tested successfully in ten subsequent cycles. Free fatty acid in the feedstock for biodiesel production should not be higher than 0.12 % to afford a product that passes the EN biodiesel standard. Product quality, ester content, free glycerol, total glycerol, density, flash point, sulfur content, kinematic viscosity, copper corrosion, cetane number, iodine value, and acid value fulfilled ASTM and EN standards. Commercially available Li₂CO₃ is suitable for direct use in biodiesel production without further drying or thermal pretreatment, avoiding the usual solid catalyst need for activation at high temperature.     

Lipase-catalyzed methanolysis of microalgae oil for biodiesel production and PUFAs concentration

A novel process with the combined use of lipase NS81006 and Novozym435 was developed for the conversion of microalgae oils for biodiesel production and PUFAs concentration. It was found that during the first-step reaction catalyzed by NS81006, the reaction rates of PUFAs were much slower compared to those with carbon length varying from C14 to C18, but significant increase for PUFAs' conversion was achieved with Novozym435 as the catalyst for the second step conversion. A fatty acid methyl ester (FAME) yield of 95% could be obtained with this two-step enzymatic catalysis. This process has great prospect for converting microalgae oils for biodiesel preparation and PUFAs concentration.     

Variables affecting the in situ transesterification of microalgae lipids

This paper describes the effect of important reaction variables on the production of biodiesel from non-edible microalgae lipids, using the acid-catalysed in situ transesterification process. The specific gravity of the biodiesel product was used to monitor the conversion progress. The results indicate that increasing the reacting alcohol volume and the temperature lead to improved fatty acid methyl ester (FAME) conversions. With the exception of in situ transesterification carried out at room temperature (23 °C), the equilibrium FAME conversions appear to approach asymptotic limits for reaction times greater than 8 h for all temperatures investigated. Stirring the reaction vessel had a significant positive influence on the rate of biodiesel formation. Increasing the moisture content of the microalgae biomass had a strong negative influence on the equilibrium FAME yield, and in situ transesterification was inhibited when the biomass water content was greater than 115% w/w (based on oil weight).     

Biodiesel production from high FFA rubber seed oil

Currently, most of the biodiesel is produced from the refined/edible type oils using methanol and an alkaline catalyst. However, large amount of non-edible type oils and fats are available. The difficulty with alkaline-esterification of these oils is that they often contain large amounts of free fatty acids (FFA). These free fatty acids quickly react with the alkaline catalyst to produce soaps that inhibit the separation of the ester and glycerin. A two-step transesterification process is developed to convert the high FFA oils to its mono-esters. The first step, acid catalyzed esterification reduces the FFA content of the oil to less than 2%. The second step, alkaline catalyzed transesterification process converts the products of the first step to its mono-esters and glycerol. The major factors affect the conversion efficiency of the process such as molar ratio, amount of catalyst, reaction temperature and reaction duration is analyzed. The two-step esterification procedure converts rubber seed oil to its methyl esters. The viscosity of biodiesel oil is nearer to that of diesel and the calorific value is about 14% less than that of diesel. The important properties of biodiesel such as specific gravity, flash point, cloud point and pour point are found out and compared with that of diesel. This study supports the production of biodiesel from unrefined rubber seed oil as a viable alternative to the diesel fuel.     

高酸值山苍籽核仁油合成生物柴油

以高酸值山苍籽核仁油(LCKO)为原料,采用二步法合成生物柴油(BD),即先用固体酸SO42-/ZrO2为催化剂进行酯化反应降低酸值,再用相转移催化剂十六烷基三甲基溴化铵(CTMAB)/NaOH催化进行酯交换反应。酯化反应的最佳条件:质量分数4%的SO42-/ZrO2,醇油摩尔比10∶1,温度68℃,反应时间4h。原油酸值降到2.52mg/g;酯交换反应的最佳条件:温度25℃,质量分数0.5%的CTMAB,1%的NaOH,醇油摩尔比6∶1,反应15min。原油酯交换率达到97.6%。此工艺无酸化废水排放,不需耐酸设备,所需时间短,能耗少,成本低。以山苍籽核仁油为原料合成生物柴油,致力于找到一条经济的、绿色的生物柴油合成路线。     

Biodiesel synthesis combining pre-esterification with alkali catalyzed process from rapeseed oil deodorizer distillate

A two-step technique combining pre-esterification catalyzed by cation exchange resin with transesterification catalyzed by base alkali was developed to produce biodiesel from rapeseed oil deodorizer distillate (RDOD). The free fatty acids (FFAs) in the feedstock were converted to methyl esters in the pre-esterification step using a column reactor packed with cation exchange resin. The acid value of oil was reduced from the initial 97.60 mg-KOH g^? 1 oil to 1.12 mg-KOH g^? 1 oil under the conditions of cation exchange resin D002 catalyst packed dosage 18 wt.% (based on oil weight), oil to methanol molar ratio 1:9, reaction temperature 60 °C, and reaction time 4 h. The biodiesel yield by transesterification was 97.4% in 1.5 h using 0.8 wt.% KOH as catalyst and a molar ratio of oil to methanol 1:4 at 60 °C. The properties of RDOD biodiesel production in a packed column reactor followed by KOH catalyzed transesterification were measured up the standards of EN14214 and ASTM6751-03.     

Esterification of sludge palm oil using trifluoromethanesulfonic acid for preparation of biodiesel fuel

Trifluoromethanesulfonic acid (TFMSA) was used to reduce the high free fatty acids (FFA) content in sludge palm oil (SPO). The FFA content of SPO was converted to fatty acid methyl ester (FAME) via esterification reaction. The treated sludge palm oil was used as a raw material for biodiesel production by transesterification process. Several working parameters were optimized, such as dosage of catalyst, molar ratio, reaction temperature and time. Less than 2% of the FFA content was the targeted value. The results showed that the FFA content of SPO was reduced from 16% to less than 2% using the optimum conditions. The yield of the final product after the alkaline transesterification was 84% with 0.07% FFA and the ester content was 96.7%. All other properties met the international standard specifications for biodiesel quality such as EN 14214 and ASTM D6751.     

Reduction of high content of free fatty acid in sludge palm oil via acid catalyst for biodiesel production

In this study, sulphuric acid (H₂SO₄) was used in the pretreatment of sludge palm oil for biodiesel production by an esterification process, followed by the basic catalyzed transesterification process. The purpose of the pretreatment process was to reduce the free fatty acids (FFA) content from high content FFA (> 23%) of sludge palm oil (SPO) to a minimum level for biodiesel production (> 2%). An acid catalyzed esterification process was carried out to evaluate the low content of FFA in the treated SPO with the effects of other parameters such as molar ratio of methanol to SPO (6:1-14:1), temperature (40-80 °C), reaction time (30-120 min) and stirrer speed (200-800 rpm). The results showed that the FFA of SPO was reduced from 23.2% to less than 2% FFA using 0.75% wt/wt of sulphuric acid with the molar ratio of methanol to oil of 8:1 for 60 min reaction time at 60 °C. The results on the transesterification with esterified SPO showed that the yield (ester) of biodiesel was 83.72% with the process conditions of molar ratio of methanol to SPO 10:1, reaction temperature 60 °C, reaction time 60 min, stirrer speed 400 rpm and KOH 1% (wt/wt). The biodiesel produced from the SPO was favorable as compared to the EN 14214 and ASTM D 6751 standard.     

Statistical optimization for biodiesel production from waste frying oil through two-step catalyzed process

The aim of this work was to investigate the optimum conditions in biodiesel production from waste frying oil using two-step catalyzed process. In the first step, sulfuric acid was used as a catalyst for the esterification reaction of free fatty acid and methanol in order to reduce the free fatty acid content to be approximate 0.5%. In the second step, the product from the first step was further reacted with methanol using potassium hydroxide as a catalyst. The Box-Behnken design of experiment was carried out using the MINITAB RELEASE 14, and the results were analyzed using response surface methodology. The optimum conditions for biodiesel production were obtained when using methanol to oil molar ratio of 6.1:1, 0.68 wt.% of sulfuric acid, at 51 °C with a reaction time of 60 min in the first step, followed by using molar ratio of methanol to product from the first step of 9.1:1, 1 wt.% KOH, at 55 °C with a reaction time of 60 min in the second step. The percentage of methyl ester in the obtained product was 90.56 ± 0.28%. In addition, the fuel properties of the produced biodiesel were in the acceptable ranges according to Thai standard for community biodiesel.     

微拟球藻油脂萃取及脱脂藻水热液化

为提高微藻的综合利用效率,使用不同的溶剂系统分别对干、湿微拟球藻进行油脂萃取,并对脱脂后的藻渣进行水热液化实验,探究溶剂萃取脱脂对微藻水热液化产物的影响。溶剂萃取的结果表明,极性溶剂对油脂的萃取率达到25.0%,但对脂质的萃取缺乏选择,萃取物的脂肪酸甲酯产率仅为29.68%;混合溶剂萃取的脂肪酸甲酯回收率达到57.70%。脱脂后的微拟球藻水热粗油产率为27.7%~34.6%,氮含量为5.29%~6.68%,主要由脂肪酸、脂肪酸酯、脂肪酸酰胺、长链烃类、胺类、含氧化合物和含氮杂环化合物组成。经甲醇萃取后的湿藻水热粗油产率为34.6%,氮含量为5.44%,过程能耗低,表明甲醇萃取湿藻结合水热液化具有一定的应用前景。