Production scale process intensification for biodiesel - a cost effective solution at 100 tonnes per day

摘要

Biodiesel is a diesel fuel equivalent made from vegetable oil. Processes for the manufacture of Biodiesel (or Fatty Acid Methyl Ester) were extensively published and patented in the 1930's, but it is only in recent years that much effort and investment have been afforded to the large scale production of Biodiesel fuel. The environmental benefits of using such fuels have been encouraged by duty breaks from various governments in Europe. The consequence of these duty reductions have resulted in fast growing industries in France, Belgium, Germany and the UK although the UK has a much smaller duty reduction and has therefore seen much more conservative growth. To approach a growth market quickly and with a competitive edge, BHR Biofuels Ltd applied BHR Group's Process Intensification strategy, used successfully for many years in the Specialty and Fine Chemicals industries. This relatively new design methodology allows a single design effort to achieve in one cycle a very efficient, compact reactor design. A brief survey of the industry will reveal many batch reactor systems (with 1 to 3 hr batch times) and a variety of solid catalyst, loop, CSTR and co-solvent approaches. The variety of approaches used is often a key indicator that the main problems of the process have not been solved, and that this led us to conclude that it would be a good candidate for Process Intensification. Since transesterification reactions often have fast kinetics with reaction times of just a few seconds, the existence of many systems with >10 minute reaction times suggests very inappropriate reactors are being used. Even relatively intense systems using high pressure and temperature have 15 to 30 minute residence times.