固定化脂肪酶催化废油合成生物柴油

研究了固定化假丝酵母99-125脂肪酶在有溶剂的体系下催化废油合成生物柴油过程中,油醇摩尔比、有机溶剂性质、底物浓度、体系含水量、甲醇流加等因素对反应过程的影响.研究结果表明,在最佳实验条件下,反应转化率最高可达92％,酶的使用寿命可达7批以上.     

固定化脂肪酶催化酯交换制备生物柴油的研究进展

生物酶法生产生物柴油具有化学催化法不可比拟的优越性,是工业化生产的发展方向。介绍了固定化脂肪酶在催化油脂酯交换制备生物柴油方面的应用,对影响酯交换反应的脂肪酶源、底物摩尔比率、酰基受体、水含量、反应温度、副产物等因素进行了综述。     

多孔玻璃珠固定化脂肪酶及其催化合成生物柴油

以多孔玻璃珠为载体,采用共价法对假丝酵母99-125脂肪酶进行了固定,对比了固定化酶与游离酶的最适反应温度、pH值以及热稳定性.并以所制备的固定化酶为催化剂,在微水体系中利用菜籽油合成生物柴油,考察了溶剂量、体系水含量、甲醇等因素对固定化酶催化性能的影响,研究了固定化酶的操作稳定性.     

复合固定化脂肪酶催化餐厨废弃油脂合成生物柴油

探讨了复合固定化脂肪酶(Rhizopus oryzae lipase和Candida rugosa lipase)催化餐厨废弃油脂合成生物柴油的工艺条件。实验结果表明,单独使用1,3位专一性脂肪酶R.oryzae lipase催化餐厨废弃油脂,反应18h,生物柴油转化率达到70%;单独使用非专一性脂肪酶C.rugosa lipase,反应30h,生物柴油转化率可达20%。为了更有效提高生物柴油转化率,采用1,3位专一性脂肪酶R.oryzae lipase和非专一性脂肪酶C.rugosa lipase复合固定化脂肪酶催化合成生物柴油,反应21h,生物柴油转化率可达到96.5%。同时对该复合酶的稳定性进行了实验,在连续催化反应10个批次(300h)后,生物柴油转化率仍保持在80%以上。     

蚕丝固定化脂肪酶催化性能研究

研究了蚕丝固定化脂肪酶对橄榄油的催化水解特性，发现在５５℃，ｐＨ＝８．２的条件下，固定化脂肪酶活性最高。底物浓度高达５７％（Ｖ／Ｖ）时，仍无抑制，适宜的搅拌速度是４００～４５０ｒｐｍ。在上述条件下，固定化脂肪酶间歇水解橄榄油，重复使用１０次水解率从９６．５％降至５３．０％，间歇水解猪油的半衰期约为２６０ｈ。     

固定酶法催化合成生物柴油Ⅰ.大孔树脂固定化脂肪酶的制备

研究了用于生物柴油酶催化的大孔树脂固定化脂肪酶的制备过程,考察和优化了脂肪酶固定化方法及条件。结果表明,采用大孔树脂D3520作载体,以载体涂布法固定化脂肪酶的最适固定化条件为:酶用量为酶∶树脂=0.16∶1(质量比),吸附时间1~3 h,pH值范围为9.0~9.4,固定化温度40℃。酶活力可达91.49 U/g,酶活回收率约为54%。     

复合固定化脂肪酶催化麻疯树油生产生物柴油

对固定化复合脂肪酶催化麻疯树油合成生物柴油进行了研究,利用3因素5水平中心旋转设计的响应曲面法对反应条件进行了优化,研究了复合酶用量、复合酶配比及底物配比对反应的影响。优化结果为复合酶用量为0.27 g,N435占总酶质量的比例为0.15,乙酸甲酯与麻疯树油的摩尔比为10.10,预测生物柴油得率为72.55 %,与实际产率74.34 %吻合较好。并建立了复合酶催化合成生物柴油反应的动力学方程,反应为双底物抑制,符合乒乓机制。     

脂肪酶固定化及催化酯化反应

本研究报道了利用吸附法和化学键合法将白地霉脂肪酶固定化于五种载体上，用吸附法固定化的脂肪酶保持了高的活性。在有机溶剂中，固定化酶催化了长链脂肪酸与醇的酯化反应，酯化率可达９４％。固定化过程并未改变脂肪酶的选择性。固定化脂肪酶可重复使用。     

脂肪酶催化食用废油制备生物柴油

利用脂肪酶为催化剂,食用废油与甲醇反应,制备生物柴油,最佳酯化反应条件为反应温度50℃、脂肪酶催化剂用量为原料量的3%、甲醇与食用废油体积比为3∶1、共溶剂丁酮量为甲醇量的1/6、pH=7,反应时间4h,生物柴油产率可达到78%,对产品的各项指标测定,均达到GB/T20828-2007要求,指标并与0#石化柴油相接近。     

脂肪酶催化非食用植物油制备生物柴油的过程优化

以麻疯树油、亚麻油、乌柏油为原料油,采用固定化脂肪酶Lipozyme TL IM,在3.0 g油、1 mL正己烷、醇油摩尔比为3.5∶1、固定化酶质量为油质量20%的条件下进行生物柴油的制备,通过脂肪酸甲酯产率和组成分析,以考察生物柴油制备的影响因素,进行反应时间优化.结果表明,酶的催化作用对脂肪酸组分不存在选择性,且...     

硅基MCF材料固载脂肪酶转化餐饮废油产生物柴油

引言"地沟油"重返餐桌现象日益成为关系民众身体健康、社会和谐发展的焦点,开发合理有效处置方式,挖掘餐饮废油的剩余经济价值,是解决"地沟油"问题的根本出路。长链脂肪酸和低碳醇经过酯化反应后生成的脂肪酸酯,可以替代石油炼制的柴油作为车用燃料[1-2],即生物柴油。研究表明餐     

废食用油脂固定床酶法合成生物柴油研究

利用废食用油脂合成生物柴油,既能够实现废弃物的清洁利用,又能提供可再生的绿色能源。采用固定化假丝酵母脂肪酶为催化剂,在三级固定床反应器内,采用分级流加甲醇的方式,每级醇油摩尔比为1∶1,探讨了酶质量分数、溶剂质量分数、水质量分数、温度、反应液流速等与产物中甲酯质量分数的关系。实验结果表明,当油中酶、溶剂、水的质量分数分别为25%,15%,10%,反应液流速为1.2 mL/min,温度为45℃时,产物中甲酯质量分数达到最大值91.08%,其中油酸甲酯质量分数最高。产品经过精制后,理化性质符合美国和德国生物柴油标准,绝大多数指标优于我国0#柴油。     

Conversion of vegetable oil to biodiesel using immobilized Candida antarctica lipase

Biodiesel derived from vegetable oils has drawn considerable attention with increasing environmental consciousness. We attempted continuous methanolysis of vegetable oil by an enzymatic process. Immobilized Candida antarctica lipase was found to be the most effective for the methanolysis among lipases tested. The enzyme was inactivated by shaking in a mixture containing more than 1.5 molar equivalents of methanol against the oil. To fully convert the oil to its corresponding methyl esters, at least 3 molar equivalents of methanol are needed. Thus, the reaction was conducted by adding methanol stepwise to avoid lipase inactivation. The first step of the reaction was conducted at 30°C for 10 h in a mixture of oil/methanol (1:1, mol/mol) and 4% immobilized lipase with shaking at 130 oscillations/min. After more than 95% methanol was consumed in ester formation, a second molar equivalent of methanol was added and the reaction continued for 14 h. The third molar equivalent of methanol was finally added and the reaction continued for 24 h (total reaction time, 48 h). This three-step process converted 98.4% of the oil to its corresponding methyl esters. To investigate the stability of the lipase, the three-step methanolysis process was repeated by transferring the immobilized lipase to a fresh substrate mixture. As a result, more than 95% of the ester conversion was maintained even after 50 cycles of the reaction (100 d).     

响应面法优化固定化洋葱伯克霍尔德菌脂肪酶回收工艺的研究

酶法制备生物柴油工艺引起了越来越多的关注。本文以脂肪酶回收前后脂肪酸甲酯得率之比作为检测指标,采用响应面法对自行制备的固定化洋葱伯克霍尔德菌脂肪酶的回收工艺参数进行了优化,并利用软件SAS 9.0对实验数据进行分析。确定的最佳回收条件:回收溶剂用量20.4 mL,回收温度40.2℃,回收时间20 m in。此条件下,验证试验脂肪酶回收率最大可达98.26%,与回归模型预测最优条件下脂肪酶回收率99.59%非常接近,且使用30次后,其回收效率依然接近100%。R2=96.63%显示该回归模型在分析脂肪酶回收率方面具有极高的准确性和可信度。     

棉籽油酯交换法合成生物柴油的工艺研究

介绍了利用复合碱性催化棉籽油酯交换合成生物柴油的工艺过程,正交实验得出的适宜工艺条件为:醇油摩尔比为5.5∶1,反应时间50 min,反应温度35℃,催化剂用量1.0%,产率可达96%。并比较了生物柴油与0#柴油的性能。     

固体碱催化剂用于油脂甲醇酯交换反应制备生物柴油

固体碱催化剂用于酯交换反应制备生物柴油有易分离、流程简单的优点。通过金属氧化物活性筛选,发现氧化钙具有很好的酯交换反应活性。将乙酸钙溶液等体积浸渍负载于碱性载体MgO上,并煅烧得到了氧化钙负载量为16.5％(质量)的CaO/MgO混合氧化物催化剂,其在油脂甲醇酯交换反应制备生物柴油的过程中具有高的反应活性。在64.5℃、醇油比18∶1 、催化剂用量2%、反应3.5 h条件下,油脂转化率为92%,接近传统的液体强碱NaOH的催化能力。用XRD、AAS、XPS、CO2 -TPD等对制得的系列催化剂进行了表征,发现催化剂的碱强度对酯交换反应有着重要的影响。通过选择合适的载体、含钙前驱体和氧化钙负载量可以增加负载型氧化钙催化剂的强碱性位,提高催化剂的反应活性。     

Continuous production of biodiesel fuel from vegetable oil using immobilized Candida antarctica lipase

Candida antarctica lipase is inactivated in a mixture of vegetable oil and more than 1∶2 molar equivalent of methanol against the total fatty acids. We have revealed that the inactivation was eliminated by three successive additions of 1∶3 molar equivalent of methanol and have developed a three-step methanolysis by which over 95% of the oil triacylglycerols (TAG) were converted to their corresponding methyl esters (ME). In this study, the lipase was not inactivated even though 2∶3 molar equivalent of methanol was present in a mixture of acylglycerols (AG) and 33% ME (AG/ME33). This finding led to a two-step methanolysis of the oil TAG: The first-step was conducted at 30°C for 12 h with shaking in a mixture of the oil, 1∶3 molar equivalent of methanol, and 4% immobilized lipase; the second-step reaction was done for 24 h after adding 2∶3 molar equivalent of methanol (36 h in total). The two-step methanolysis achieved more than 95% of conversion. When two-step reaction was repeated by transferring the immobilized lipase to a fresh substrate mixture, the enzyme could be used 70 cycles (105 d) without any decrease in the conversion. From the viewpoint of the industrial production of biodiesel fuel production, the two-step reaction was conducted using a reactor with impeller. However, the enzyme carrier was easily destroyed, and the lipase could be used only several times. Thus, we attempted flow reaction using a column packed with immobilized Candida lipase. Because the lipase packed in the column was drastically inactivated by feeding a mixture of AG/ME33 and 2∶3 molar equivalent of methanol, three-step flow reaction was performed using three columns packed with 3.0 g immobilized lipase. A mixture of vegetable oil and 1∶3 molar equivalent of methanol was fed into the first column at a constant flow rate of 6.0 mL/h. The eluate and 1∶3 molar equivalent of methanol were mixed and then fed into the second column at the same flow rate. The final step reaction was done by feeding a mixture of eluate from the second column and 1∶3 molar equivalent of methanol at the same flow rate. The ME content in the final-step eluate reached 93%, and the lipase could be used for 100 d without any decrease in the conversion.