title: Biodiesel production by a mixture of Candida rugosa and Rhizopus oryzae lipases using a supercritical carbon dioxide process.
abstract: In this study, various factors, such as temperature, pressure, agitation speed, water content, and the concentration and ratio of immobilized ROL and CRL were investigated for the efficient enzymatic production of biodiesel using a supercritical carbon dioxide process. Furthermore, a stepwise reaction method for the maintenance of immobilized lipase activity was optimized. Optimal conditions for biodiesel production were determined to be as follows: 130 bar pressure, 45 °C temperature, 250 rpm agitation speed, 10% water content, and 20% immobilized ROL and CRL (1:1). When batch process was performed under optimal conditions, the biodiesel conversion yield was 99.13% at 3 h. Biodiesel conversion yield was 99.99% at 2 h when 90 mmol methanol was used in a stepwise reaction. Moreover, the conversion yield of biodiesel produced by the repeated recycling of immobilized lipase in the stepwise reactions was 85% after 20 reuses.
authors.affiliation: Department of Chemical and Biological Engineering, Korea University, 1, Anam-dong, Sungbuk-ku, Seoul 136-701, South Korea. jjong0614@korea.ac.kr
authors.forename: Jong Ho
authors.initials: JH
authors.lastname: Lee
authors.forename: Sung Bong
authors.initials: SB
authors.lastname: Kim
authors.forename: Seong Woo
authors.initials: SW
authors.lastname: Kang
authors.forename: Yoon Seok
authors.initials: YS
authors.lastname: Song
authors.forename: Chulhwan
authors.initials: C
authors.lastname: Park
authors.forename: Sung Ok
authors.initials: SO
authors.lastname: Han
authors.forename: Seung Wook
authors.initials: SW
authors.lastname: Kim
mesh_terms: D056804:Biofuels / Q000032:analysis*; D001709:Biotechnology / Q000379:methods*; D002175:Candida / Q000187:drug effects / Q000201:enzymology*; D002245:Carbon Dioxide / Q000494:pharmacology*; D004800:Enzymes, Immobilized / Q000378:metabolism; D008049:Lipase / Q000378:metabolism*; D011312:Pressure; D012233:Rhizopus / Q000187:drug effects / Q000201:enzymology*; D013696:Temperature; D014867:Water
chemical_list: D056804:Biofuels; D004800:Enzymes, Immobilized; D014867:Water; D002245:Carbon Dioxide; D008049:Lipase