PETR 53 |
| Biodiesel is mostly produced by alkali-catalyzed transesterification of an oil or fat. The major cost of BD production comes from the cost of the feedstock. High fatty acid-containing feedstocks such as yellow and brown greases are readily available, inexpensive, and renewable resources and hence are attractive feedstocks for the production of BD. The high free fatty acid content of these feedstocks, however, makes it difficult to produce BD using base-catalyzed transesterification. We have examined the efficacy of a series of homogeneous diarylammonium catalysts in catalyzing the esterification of the FFA present in greases (12 - 40 wt% FFA) to esters. At a catalyst loading of 1 - 3 mol%, high conversions of FFA to esters (95 - 99%) were achieved by treating the greases with 5 - 20 equiv. of methanol at 95ºC for 2h. The treated greases had a final FFA content of 0.5 - 1 wt%. We also demonstrated that the diarylammonium catalysts could be readily supported onto mesoporous silica materials such as MCM-48 and SBA-15. The silica-supported heterogeneous catalysts were equally effective in catalyzing the esterification of FFA to esters and could be readily recycled and re-used for the esterification of FFA in greases. The resulting ester-glyceride mixture could then be readily converted to esters by base-catalyzed transesterification. |
|
BioFuels: Renewable Liquid Fuels & Chemicals from Biomass
1:30 PM-4:00 PM, Monday, August 20, 2007 Boston Park Plaza -- Whittier Rm, Oral
Division of Petroleum Chemistry |