Process Development for Transesterification of Triglyceride and It''s Application

• Main Authors: Jech-Wei Chen, 陳志威
• Other Authors: Wen-Teng Wu
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/78804655289440924003

博士 === 國立清華大學 === 化學工程學系 === 91 === Abstract The ever increasing crude oil prices, limited resources and growing environmental concerns have placed greater emphasis on the need to develop viable alternative fuels. Biodiesel is one of the most promising cleaner alternative fuels produced from renewable resources. This work aims at the transesterification of triglyceride from natural resources. Immobilized lipase catalyzing transesterification of oils with alcohols is one of the methods for the production of biodiesel. However, the enzyme frequently deactivates by lower-carbon alcohols like methanol, leading to the decrease of reaction rate. An investigation into the mechanism of lipase deactivation revealed that the lower-carbon alcohol adsorbs on the surface of the immobilized enzyme, forming a barrier and thereby blocking the contact of triglyceride. Pretreatment and regeneration of using tert-butanol and 2-butanol can increase the activity of the enzyme and makes the process economically feasible. Pretreatment of the immobilized lipase (Novozyme 435) by immersion in the alcohol resulted in seven to ten fold increase in activity compared to that without pretreatment. By following complete deactivation of the enzyme by methanol, washing with tert-butanol and 2-butanol, the enzyme was successfully regenerated to about 75% and 56% of its original activity, respectively. For developing the enzymatic transesterification process, two different strategies have been investigated, i.e. a two-stage process and a dilution process. Using these two processes, 95% conversion can be achieved within the reaction time of 300 min and 63 min, respectively. In these two processes the enzyme can also maintain its activity for six months without any significant loss of activity. This process was also successfully employed for other applications like the recovery of vitamin E and phyto-sterols from the deodorized distillate of soybean oil.