Abstract
A two-step enzymatic transesterification process in a solvent-free system has been developed as a novel approach to the production of biodiesel using acid oil from rice bran oil soapstock. The acid oil consisted of 53.7 wt% fatty acids, 2.4 wt% monoacylglycerols, 9.1 wt% diacylglycerols, 28.8 wt% triacylglycerols, and 6.0 wt% others. Three immobilized lipases were evaluated as potential biocatalysts, including Novozym 435 from Candida antarctica, Lipozyme RM IM from Rhizomucor miehei, and Lipozyme TL IM from Thermomyces lanuginosus. The effects of molar ratio of acid oil to ethanol, temperature, and enzyme loading were investigated to determine the optimum conditions for the transesterification with the three immobilized lipases. The optimum conditions of the three immobilized lipases were a molar ratio of 1:5 (acid oil to ethanol), the temperature range of 30-40℃, and the enzyme loading range of 5-10%. The two-step transesterification was then conducted under the optimum conditions of each lipase. The stepwise use of Novozym 435 and Lipozyme TL IM or Lipozyme RM IM and Lipozyme TL IM resulted in similar or higher levels of yield to the individual lipases. The maximum yields obtained in both stepwise uses were ca. 92%.
Original language | English |
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Pages (from-to) | 913-921 |
Number of pages | 9 |
Journal | Journal of Oleo Science |
Volume | 65 |
Issue number | 11 |
DOIs | |
Publication status | Published - 2016 |
Bibliographical note
Funding Information:This work was carried out with the support of “Cooperative Research Program for Agriculture Science & Technology Development (Project title: Evaluation of quality and processing property of long-term stored rice, Project No. PJ011037)” Rural Development Administration, Republic of Korea.
Publisher Copyright:
© 2016 by Japan Oil Chemists’ Society.
Keywords
- Acid oil
- Biodiesel
- By-product
- Lipase
- Transesterification
ASJC Scopus subject areas
- General Chemistry
- General Chemical Engineering