Purifying e.g. acrylic acid by fractional falling film crystallization using an exchanger comprising a textured surface, in the preparation of acrylic acid obtained from propylene and/or glycerol or 3-hydroxypropionic acid

摘要

Purifying a chemical compound by fractional falling film crystallization using an exchanger comprising a textured surface, is claimed. Independent claims are included for (i) an installation for purification of a chemical compound, comprising: a crystallizer consisting of parallel-connected tubes that include a textured surface and are fed at a top by a pipe equipped with a distributor connected to a fluid supply tank, and a conduit connected to a hopper, which feeds a coolant in contact with a face of a tube wall; a hopper, initially containing the fluid to be purified; a crystallization tank whose bottom is connected with the crystallizer, where the crystallization tank first receives a charging phase to purify the liquid and then receives the liquid trickling along the tubes; a conveyor for the fluid to be purified; a pump to convey the coolant from a coolant reservoir to a coolant distributor circuit; collection reservoirs to collect impure molten medium; and collection reservoirs for molten purified medium. (ii) Method of manufacturing of acrylic acid starting from propylene and/or glycerol or acid 3-hydroxypropionic comprising a final step of recovery of acrylic acid resin purified by split crystallization with film falling using an exchanger comprising a textured surface.