Synthesis of biodiesel

Kelkar MA, Gogate PR, Pandit AB (2008) Intensification of esterification of acids for synthesis of biodiesel using acoustic and hydrodynamic cavitation. Ultrason Sonochem 15 188-194... 

Compared to the base-catalyzed synthesis of biodiesel, fewer studies have dealt with the subject of acid-catalyzed transesterification of lipid feedstocks. Among acid catalysts, sulfuric acid has been the most widely studied. In the previously mentioned work of Freedman et al., the authors examined the transesterification kinetics of soybean oil with butanol using sulfuric acid. The three reaction regimes observed (in accordance with reaction rate) for base-catalyzed reactions were also observed here. A large molar ratio of alcohol-to-oil, 30 1, was required in this system in order to carry out the reaction in a reasonable time. As expected, transesterification followed pseudo-first-order kinetics for the forward reactions (Figure 2), while reverse reactions showed second-order kinetics. 

Table 9 Reaction conditions used by Zhang et al. in the acid-catalyzed synthesis of biodiesel from waste cooking oif" ...

Finally, as indicated in this chapter, many opportunities exist for improving the synthesis of biodiesel. Use of solid catalysts and continuous processing with... 

Di Serio, M.,Tesser, R., Dimiccoli, M., Cammarotaa, F., Nastasi, M., and Santacesaria, E. 2005. Synthesis of Biodiesel via Homogeneous Lewis Acid Catalyst. / Mol. Catal. A Chem., 239,111-115. 

Xie, W X. Huang. Synthesis of biodiesel from soybean oil using heterogeneous kf/zno catalyst. Catal. Lett. 2006,107, 53-59. 

Schwarz et al. [85] studied the efficiency of different microstructured mixers followed by microchannels and their influence on the space time for obtaining high product yields. With increasing mass transfer performance of the micromixer and decreasing channel diameter of the microchannel reactors, shorter reaction times of several minutes at lower reaction temperatures compared to conventional batch reactor were obtained. Similar observations are reported for the synthesis of biodiesel in capillary microreactors [86] and in zigzag microchannels [87]. 

Orfaire, O, Buisson, P, Pierre, A C (2(X)6) Application of silica aerogel encapsulated lipases in the synthesis of biodiesel by transesterification reactions. J Mol Catal B Enzym 42(3-4) 106-113. 

Synthesis of Biodiesel Reactions Catalyzed by Acids and Bases. 

Therefore, a suitable solid catalyst for the synthesis of biodiesel is very attractive. The solid catalysts could be easily separated Irom the reaction products, avoiding corrosion and environmental problems and reducing the purification units and the cost of production (352). During the last decade, some industrial biodiesel processes reported the use of solid catalysts (353,354). A variety of solid catalysts for the synthesis of biodiesel from different triglycerides are reported in the literature. 

Tongboriboon K, Cheirsilp B, H-kittikun A. Mixed Upases for efficient enzymatic synthesis of biodiesel from used palm oil and ethanol in a solvent-free system.J Mol Catal B Enzym 2010 67 52-9. 

Adamczak, M., U. T. Bornscheuer, and W. Bednarski. 2009. The Application of Biotechnological Methods for the Synthesis of Biodiesel. European Journal of Lipid Science and Technology 111 800-813. 

Madras, G., C. Kolluru, and R. Kumar. 2004. Synthesis of Biodiesel in Supercritical Fluids. ... 

Or9aire, O., P. Buisson, and A. C. Pierre. 2006. Application of Silica Aerogel Encapsulated Lipases in the Synthesis of Biodiesel by Transesterification Reactions. Journal of Molecular Catalysis B Enzymatic 42 (3-4) 106-113. 

Rathore, V., and G. Madras. 2007. Synthesis of Biodiesel from Edible and Non-Edible Oils in Supercritical Alcohols and Enzymatic Synthesis in Supercritical Carbon Dioxide. Fuel 86 (17-18) 2650-2659. 

Varma, M. N., P. A. Deshpande, and G. Madras. 2010. Synthesis of Biodiesel in Supercritical Alcohols and Supercritical Carbon Dioxide. Fuel 89 (7) 1641-1646. 

The reaction shown is an oversimplification and items such as shifting the equilibrium toward methanol, catalyst poisoning, and pressure/temperature tradeoffs need to be considered and are the subject of a text [3]. Methanol has many uses as a solvent and is the major component of windshield washer fluid. However, most methanol is converted to other commodity chemicals such as acetic acid, formaldehyde, or dimethyl terephthalate. It can also be used directly as a fuel additive, as a component in the synthesis of biodiesel or converted to dimethyl ether or methyl-t-butyl ether (MTBE), two fuel additives. 

Chen, Y., Xiao, B., Chang, J., Fu, Y., Lv Pa. and Wang X. 2009. Synthesis of biodiesel from waste cooking oil using immobilized lipase in fixed bed reactor. Energy Conversion Manage. 50(3) 668-673.. 

D Cruz, A., Kulkarni, M.G., Meher, L.C. and Dalai, A.K. 2007. Synthesis of biodiesel from canola oil using heterogeneous base catalyst. J. Amer. Oil Chem. Soc. 84(10) 937-943. 

Shu, Q. Yang, B. Yuan, H. et al. Synthesis of biodiesel from soybean oil and methanol catalyzed by zeolite beta modified with La. Catal. Commun. 2007, 8, 2159-2165. 

Adamczak M, Bornscheuer UT, Wlodzimierz B. 2009. The application of biotechnological methods for the synthesis of biodiesel. Eur J Lipid Sci Technol 111 808-813. 

---