Bakkiyaraj S, Syed Mahin Basha, Devanesan M G, Thangavelu Viruthagiri
Biochemical Engineering Lab, Chemical Engineering Department, Annamalai University, Chidambaram, 608002, Tamilnadu, India.
Environmental Engineering Lab, Nawab Shah Alam Khan College of Engineering and Technology, Hyderabad, 500024, Telangana, India.
Environ Sci Pollut Res Int. 2016 May;23(10):9276-83. doi: 10.1007/s11356-015-4583-7. Epub 2015 May 5.
Vegetable oils are used as raw materials for biodiesel production using transesterification reaction. Several methods for the production of biodiesel were developed using chemical (alkali and acidic compounds) and biological catalysts (lipases). Biodiesel production catalyzed by lipases is energy and cost-saving processes and is carried out at normal temperature and pressure. The need for an efficient method for screening larger number of variables has led to the adoption of statistical experimental design. In the present study, packed bed reactor was designed to study with mixed immobilized biocatalysts to have higher productivity under optimum conditions. Contrary to the single-step acyl migration mechanism, a two-step stepwise reaction mechanism involving immobilized Candida rugosa lipase and immobilized Rhizopus oryzae cells was employed for the present work. This method was chosen because enzymatic hydrolysis followed by esterification can tolerate high free fatty acid containing oils. The effects of flow rate and bed height on biodiesel yield were studied using two factors five-level central composite design (CCD) and response surface methodology (RSM). Maximum biodiesel yield of 85 and 81 % was obtained for jatropha oil and karanja oil with the optimum bed height and optimum flow rate of 32.6 cm and 1.35 L/h, and 32.6 cm and 1.36 L/h, respectively.
植物油被用作通过酯交换反应生产生物柴油的原料。人们开发了几种使用化学催化剂（碱和酸性化合物）和生物催化剂（脂肪酶）生产生物柴油的方法。脂肪酶催化的生物柴油生产是节能且低成本的过程，在常温常压下进行。由于需要一种高效的方法来筛选大量变量，因此采用了统计实验设计。在本研究中，设计了填充床反应器，以研究混合固定化生物催化剂，以便在最佳条件下获得更高的生产率。与单步酰基迁移机制不同，本研究采用了涉及固定化皱褶假丝酵母脂肪酶和固定化米根霉细胞的两步逐步反应机制。选择该方法是因为酶促水解后进行酯化可以耐受高游离脂肪酸含量的油。使用二因素五水平中心复合设计（CCD）和响应面方法（RSM）研究了流速和床高对生物柴油产率的影响。对于麻风树油和麻疯果油，分别在最佳床高32.6厘米和最佳流速1.35升/小时以及32.6厘米和1.36升/小时的条件下，生物柴油的最大产率分别为85%和81%。
