Research and development of a sub-critical methanol alcoholysis process for producing biodiesel using waste oils and fats

Waste oils and fats (WOFs) are non-edible oils generated in amounts of more than 30 million and 10 million tons/year in China, respectively, from the production and consumption of cooking oil, and which would pollute the environment if disposed of improperly. Due to its poor quality, it is very difficult to transform WOFs to biodiesel by base catalyzed transesterification, especially when these have high free fatty acids and impurities. A new technology, sub-critical methanol alcoholysis process (SRCA process), was developed by SINOPEC Research Institute of Petroleum Processing for producing biodiesel from WOFs. The technical problems that were solved included how to dissolve WOFs in methanol, how to moderate the reaction conditions, how to transform WOFs into more biodiesel, and how to improve product quality. The first industrial demonstration unit of SRCA process with a scale of 60 kton/year biodiesel was set up in 2009, and it had been operated continuously to produce biodiesel from soybean acid oil, palm acid oil, and cooking oil. The biodiesel product quality fulfil the requirements of National Standard (GB/T 20828-2007). (C) 2013, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V All rights reserved.