Lipase catalyzed transesterification of plant oils with dialkyl carbonates

• Main Author: Herawan, Tjahjono
• Other Authors: Warwel, Siegfried
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: Publikationsserver der RWTH Aachen University 2004
• Subjects: info:eu-repo/classification/ddc/660; Ölsaat; Pflanzenöl; Reaktivextraktion; Umesterung; Kohlensäureester; Lipasen; Technische Chemie; Dialkyl Carbonates; Alkyl esters; Lipase; Antarc*; Antarctica
• Online Access: https://publications.rwth-aachen.de/record/59717; https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-121478%22

Dialkyl carbonates, especially dimethyl- and diethyl carbonate, have been explored as raw materials for lipase-catalyzed methyl and ethyl ester synthesis and as organic solvents for oilseed extraction. Palm kernels and other potential tropical oilseeds were used as raw materials for this study. The lipase B from Candida antarctica (in the immobilized forms: Novozym 435 and Candida B. Silica), was found to be effective for transesterifying palm kernel oil and other plant oils with either dimethyl or diethyl carbonate. Some key aspects of lipase-catalyzed ester synthesis such as the source of the alkyl donor, the role of water, and the effect of temperature were also investigated. Two methods of reactive extraction were also examined in this study. The first method is soxhlet reactive extraction under reduced pressure. Using palm kernels, the best temperature for soxhlet extraction was 60oC (consequently 360 mbar), solvent/seed ratio of 7.3 ml dimethyl carbonate/g seed and addition of 0.2% water to the solvent. Under this condition 55% (% w/w of seed) lipid was extracted and of that 60% was converted to methyl esters. The second method is in-situ reactive extraction (i.e. extraction and transesterification in the same pot and at the normal pressure). By addition of 0.2% water, after 24 hour reactive extraction yielded 59% (w/w of seed) and about 90% ester thereof.