Lipase-catalyzed biodiesel production

Wang, L., Du, W., Liu, D., Li, L., and Dai, N. 2005. Lipase-catalyzed biodiesel production from soybean oil deodorizer distillate with absorbent present in fert-butanol system. J. Mol Catal. B Enzym., 43, 29-32. 

Ha SH, Lan MN, Lee SH, Hwang SM, Koo Y-M (2007) Lipase-catalyzed biodiesel production from soybean oil in ionic Uquids. Enzyme Microb Technol 41 480-483... 

Yamada H, Sorimachi Y, Tagawa T (2007) Operation optimization of lipase-catalyzed biodiesel production. J Chem Eng Japan 40(7) 571-574... 

Wang, L., W. Du, D. Liu, L. Li, and N. Dai. 2006. Lipase-Catalyzed Biodiesel Production from Soybean Oil Deodorizer Distillate with Absorbent Present in tert-Butanol System. Journal of Molecular Catalysis B Enzymatic 43 (l-4) 29-32. 

Figure 7.6 Unit operations and corresponding works that can be done to reduce the cost of lipase-catalyzed biodiesel production (Zhao et al., 2015).

Y.L., and Shieh, C.J. (2011) Continuous production of lipase-catalyzed biodiesel in a packed-bed reactor optimization and enzyme reuse study. J. Biotned. Biotechnol., Article ID 950725, 6 pp. doi 10.1155/2011/950725... 

Du, W., Xu, Y., and Liu, D. 2003. Lipase-catalyzed transesterification of soya bean oil for biodiesel production during continuous batch operation. Biotechnol. Appl. Biochem.,38,103-106. 

Fukuda et al. (2001) reported enzymatic transesterification using lipase has become more attractive for biodiesel production, since the glycerol produced as a by-product can easily be recovered and the purification of FAME is simple to accomplish. Lipases shown in Table 9.1 can effectively catalyze the transesterification of triglycerides and the problems mentioned above can be circumvented by using the enzyme. 

RSM is an efficient statistical technique that optimizes multiple variables to search for the optimal point with minimum number of experiments (Box et al., 1978 Khuri and Cornell, 1987). Recently, optimization of lipase-catalyzed production of various biodiesels (FAME) by RSM has been investigated. 

Esters of fatty acids with monohydric alcohols find applications as emollients in cosmetics. They are prepared by acid- or base-catalyzed (trans)esterifications [200, 205]. As with biodiesel production, the use of enzymatic catalysis offers potential benefits but in the case of these specialty fatty acid esters there is a special advantage the products can be labelled as natural. Consequently, they command a higher price in personal care products where natural is an important customer-perceived advantage. Examples include the synthesis of isopropylmy-ristate by CaLB-catalyzed esterification [206] and n-hexyl laurate by Rhizomucor miehei lipase (Lipozyme IM-77)-catalyzed esterification [207] (see Fig. 8.38). 

Lipase-Catalyzed Transesteriiication of Rapeseed Oil for Biodiesel Production with tert-Butanol... 

As compared to other catalyst types used in the production of biodiesel, enzymes have several advantages. They enable conversion under reaction conditions milder than those required for chemical catalysts. Moreover, in the enzymatic process, both the transesteiification of triglycerides and the esterification of fi e fatty acids occur in one process step. However, lipase-catalyzed transesterifications induce a series of drawbacks. As compared to conventional alkaline catalysis protocols, reaction efficiency tends to be rather poor, and thus enzymatic catalysis generally necessitates significantly longer reaction times and higher enzyme amounts. The primary obstacle to the application of enzymes in industrial processes is their relatively high cost [7]. 

In the enzymatic process utilized herein for the production of fatty acid methyl ester fixrm rapeseed oil, several factors are known to influence conversion. The initial step of this study involved the identification of factors likely to influence conversion, fri this study, tert-butanol was applied in lipase-catalyzed methanolysis. fert-Butanol has been utilized previously in several enzymatic process, including sorbitan ester synthesis [6, 15]. It has also been confirmed that terf-butanol is inert in the Novozym 435-catalyzed methanolysis of rapeseed oil for the production of biodiesel [12]. 

Generally, alkali-catalyzed transesterification is conducted at near the boiling point of the alcohol, but enzyme-catalyzed transesterification is performed at a low temperature to prevent the loss of lipase activity [9]. The low reaction temperature was also found to be desirable, as the reaction temperature was closely related to the energy cost inherent to the process of biodiesel production [3]. 

Hsu, A.-E K. Jones T.A. Foglia W.N. Marmer. Immobilized lipase-catalyzed production of alkyl esters of restaurant grease as biodiesel. Biotechnol. Appl. Biochem. 2002, 36, 181-186. 

Pizarro, A.V.L. E.Y. Park. Lipase-catalyzed production of biodiesel fuel from vegetable oils contained in waste activated bleaching earth. Process Biochem. 2003, 38, 1077—1082. 

Martinez I, Markovits A, Chamy R et al. (2004) Lipase-catalyzed solvent-free transesterification of wood sterols. Appl Biochem Biotechnol 112 55-62 Matsumoto T, Takahashi S, Kaieda M et al. (2001) Yeast whole-cell biocatalyst constructed by intracellular overproduction of Rhizopus oryzae lipase is applicable to biodiesel fuel production. Appl Microbiol Biotechnol 57(4) 515-520 Maurer K (2004) Detergent proteases. Curr Opin Biotechnol 15 330-334... 

Contrary to these processes, enzyme-catalyzed reactions using lipases have proven to be an interesting alternative for industrial-scale biodiesel production in order to reduce production costs. Lipases (triacylglycerol acyl-hydrolases, E.C. 3.1.1.3.) are powerful tools that can catalyze not only hydrolysis but also various synthetic reactions including esterification and transesterification. 

Du, W Xu, Y Liu, D Zeng, J. Comparative study on lipase-catalyzed transformation of soybean oil for biodiesel production with different acyl acceptors. Journal of Molecular Catalysis B Enzymatic, 2004, v. 30 (3-4), 125-129. 

Vieira, APDA da Silva, MAP Langone, MAP. Biodiesel production via esterification reactions catalyzed by lipase. Latin American applied research, 2006, v. 36,283-288. 

The use of lipase-catalyzed alcoholysis (Fig. 27) in biodiesel production appears as an attractive possibility because of mild reaction conditions and easy removal and low toxicity of the enzyme, even though enzyme-catalyzed biodiesel processes have not yet found widespread use (44). One of the obstacles has been the inactivation of lipases by methanol. To overcome the problem, stepwise addition of methanol and the use of cosolvents have been proposed. Shimada and co-workers (45), for instance, reported 90% yield of FAME from waste oil. The enzyme, Novozym 435, was stable for 100 days, and even after reuse of 50 times, the enzyme still stayed active. 

Biodiesel production using the biocatalyst lipase avoids the disadvantages of the alkaline process without the need for subsequent wastewater treatment (Taher et al., 2011). Additionally, lipases can operate in mild conditions with a high substrate selectivity. M. miehei, R. oryzae, C. antarctica, and P. cepacia are all common lipases found to be capable of catalyzing oil transesterification in order to produce biodiesel. 

---