Research on Hydrogenation of FAME to Fatty Alcohols at Supercritical Conditions

It is hard to develop biodiesel industry currently as a consequence of the rapid increase in the prices of animal and vegetable oil in recent years. Production of high-value bulk chemicals from biodiesel (fatty acid methyl esters) and its by-product of glycerol is an effective way to overcome the difficulties and to promote the steady development of biodiesel industry. However, the choice of target products and technologic routes for producing them should follow three principles: 1) biomass feedstocks are cheaper than petroleum products when they are used as raw materials, 2) process being developed is simple and environmentally-friendly, 3) the target products are in line with the market demands [1]. Production of fatty alcohols (FA) from fatty acid methyl esters (FAME) by hydrogenation under supercritical conditions is in line with these principles. The study on hydrogenation of FAME to FA using propane and carbon dioxide as solvents under supercritical conditions has been reported previously. But the reaction is carried out above 15.0 MPa [2-5], and such high operation pressure will seriously increase the capital and operating costs. It is thus clear that a low-pressure hydrogenation process for FAME conversion to FA under supercritical conditions can lead to reduction in the capital and operating costs of the process while the advantages of supercritical reactions are maintained, which can also lead to great social and economic benefits.