Glycerol-based solid acid catalysts useful for the esterification of fatty acids, a process and use thereof

Abstract

The present invention provides a novel glycerol-based heterogeneous solid acid catalyst by simultaneous partial carbonization and sulfonation of crude glycerol obtained as a by-product during the biodiesel process. Solid acid catalyst with similar activity is also prepared from glycerol pitch (by-product of fat splitting) and technical grade glycerol. These glycerol-based solid acid catalysts are employed for esterification of fatty acids and fatty acid present in the high and low free fatty acid (FFA) containing vegetable oils like rice bran, karanja and jatropha; fatty acid distillate; deodorizer distillate and acid oil which are being used as raw materials for the preparation of biodiesel. These catalysts are highly active, reusable and simplify the biodiesel process particularly for fatty acids or high FFA containing vegetable oils by replacing the traditional homogeneous mineral acid catalysts.