Biodiesel production with enzymatic approaches
Lipase-catalyzed transesterification from renewable oils for biodiesel production has many advantages over chemical approaches though the latter has been put into the industrialization for biodiesel production. However, the low stability (poor operational life) and the high cost of the lipase have been thought to be the main hurdle to the industrialization of lipase-catalyzed biodiesel production.
We have proposed a novel route and the operational life of the immobilized lipase could be improved over 50-fold than traditional enzymatic approaches. This novel route is thought to be very promising for the commercialization of biodiesel production since it would reduce the lipase cost dramatically by significantly improving the stability and the operational life of the lipase. The demonstrational test in a pilot plant with capacity of 100kg/d biodiesel was successful. A new plant with 20,000ton/year capacity has been constructed in Hunan, China and it was put into operation in Dec. 8, 2006. The results from the full scale operation are even better than in the pilot plant demonstration.
Integrated production of 1,3-PDO from by-product glycerol
As a by-product, glycerol will be yielded at about 10% of biodiesel during the process of biodiesel production. How to convert glycerol has become a common problem which has to be resolved if considering large amount of biodiesel production. Integrated production of 1,3-propanediol (PDO) from glycerol could be a promising way to improve the profit of the whole process during biodiesel production.
1,3-PDO is a valuable chemical material and especially it could be copolymerizes with terephthalic acid (or methyl ester) to form polytrimethylene terephthalate (PTT). PTT has excellent properties compared to other polymers such as PET. 1,3-PDO can be synthesized from petrochemicals by chemical approaches or manufactured from renewable substrates by fermentation. However, it’s well known that there are many disadvantages associated with chemical approaches for 1,3-PDO production, such as low Selectivity, high temperature and high pressure needed etc. Especially the material for chemical approaches is unrenewable and some intermediates such as ethylene oxide and acrolein are explosive or high toxic. Therefore, fermentation approaches for 1,3-PDO production have drawn more and more attention by considering its advantages over chemical method such as relatively low investment, mild reaction conditions and using renewable sources as the starting materials.
We have proposed a novel flexible process for 1,3-PDO production from glycerol or glucose, and the demonstration was finished in pilot plant at the end of 2003 and in industrial scale(50m3fermentor) in June 2006. The purity of final product 1,3-PDO is as good as 99.92%. Some 1,3-PDO sample was tested for PTT polymerization by Chinese and Japanese companies. The results showed that the key characteristics (such as inherent viscosity) of PTT polymerized with the 1,3-PDO produced by biological route are even better than that by chemical route. Currently the large-scale production of 1,3-PDO(20000tons/year) is being under construction.
Based on the above technology, It could be well integrated to produce biodiesel and 1,3-PDO.
中文
