公开(公告)号：US3642829A

公开(公告)日：1972-02-15

申请号：US3642829D

申请日：1970-01-27

Applicant: UCB SA

Inventor： WEYENS ERNEST

IPC: C07D307/60 ,  C07C51/31 ,  C07C51/56 ,  B01D3/34 ,  C07C57/14

CPC classification number: C07C51/313 ,  C07C51/56 ,  C07C57/145

Abstract: CONTINUOUS PROCESS FOR THE PREPARATION OF MALEIC ANHYDRIDE WHICH COMPRISES: (A) CONCENTRATING A MALEIC ACID SOLUTION (E.G. FROM WASHING EFFUENT OF CATALYTIC OXIDATION OF BENZENE) AT 100-150*C. AND 400-760 MM. HG; (B) CONVERTIG THE DEHYDRATED MALEIC ACID FROM (A) AT 150-200*C. AND 40-300 MM. HG INTO A LIQUID PHASE OF IMPURE MALEIC ACID AND A PURIFIED GASEOUS PHASE OF MALEIC ANHYDRIDE AND WATER VAPOUR; (C) TREATING THE LIQUID PHASE FROM (B) WITH MALEIC ACID, FILTERING OFF THE IMPURITIES INCLUDING ANY FUMARIC ACID AND EITHER RECYCLING THE PURIFIED MALEIC ACID FILTRATE PARTLY TO (A) AND PARTLY TO (B) OR REMOVING SAID FILTRATE FORM THE SYSTEM; (D) CONDENSING THE GASEOUS PHASE FORM (B) AT A TEMPERATURE ABOVE THE DEWPOINT OF WATER GIVING SUBSTANTIALLY PURE MALEIC ANHYDRIDE AND WASHING THE RESIDUAL VAPOUR WITH WATER AND EVENTUALLY RECYCLING THE SOLUTION CONTAINING MALEIC ACID TO (A).

公开(公告)号：GB1260428A

公开(公告)日：1972-01-19

申请号：GB4222969

申请日：1969-08-25

Applicant: UCB SA

Inventor： WEYENS ERNEST

IPC: B01D1/22

Abstract: 1,260,428. Evaporators, film type. U.C.B. (UNION CHIMIQUE-CHEMISCHE BEDRIJVEN) S.A. 25 Aug., 1969, No. 42229/69. Heading BIB. [Also in Division C2] In an evaporator comprising a heated vertical cylinder 1 wherein a film of liquid flows down the inner wall of the cylinder and is wiped by rotor 3 mounted on an upper bearing (not shown) and a lower bearing 6, obstruction by evaporation residues in the zone of the lower bearing is prevented by collecting the residues in dish 17 which is supplied with solvent by means of pipe 22, annular duct 20 and passages 21. The solution of residues in solvent flows over the edge 18 of dish 17, and leaves the evaporator through outlet 10. The evaporator may be used to heat maleic acid to form maleic anhydride vapour and watervapour; in this case water is used as solvent for the residues which comprise maleic acid, resins and furmaric acid.

公开(公告)号：DE2003684A1

公开(公告)日：1970-08-06

申请号：DE2003684

申请日：1970-01-28

Applicant: UCB SA

Inventor： WEYENS ERNEST

IPC: C07D307/60 ,  C07C51/31 ,  C07C51/56 ,  C07C51/18

Abstract: 1,242,320. Maleic anhydride. UCB (UNION CHIMIQUE-CHEMISCHE BEDRIJVEN) S.A. 28 Jan., 1970 [30 Jan., 1969], No. 5221/69. Heading C2C. Maleic anhydride of at least 99% by weight purity and containing 0-0À1% by weight of fumaric acid is prepared in a continuous process from an aqueous solution of maleic acid by: (a) Heating the maleic acid solution in a concentration zone at a temperature of between 100‹ and 150‹ C. and at a pressure of between 400 and 760 mm. Hg until the water content of the maleic acid is reduced to 0-10% by weight; (b) Treating the maleic acid obtained in stage (a) in a conversion zone at a temperature of between 150‹ and 200‹ C. and at a pressure of between 40 and 300 mm. Hg until from 10 to 97% by weight of the maleic acid is converted into maleic anhydride, to give a liquid phase of impure maleic acid and a purified gaseous phase containing maleic anhydride and water vapour; (c) Treating the impure liquid phase produced in stage (b) with an aqueous solution of maleic acid in a dissolution and filtration zone to provide a solid residue containing the impurities and any fumaric acid which may have been formed, which is removed from the system, and a filtrate consisting of an aqueous solution of purified maleic acid, which is either recycled partly to stage (a) and partly to the impure liquid phase produced in stage (b) or is removed from the system; (d) Condensing in a condensation zone the gaseous phase consisting of maleic anhydride and water vapour produced in stage (b) at a temperature higher than the dewpoint of the water vapour present in the gaseous phase, thus obtaining maleic anhydride of the desired purity; washing the residual vapour with water and returning, if desired, to stage (a) the solution thus obtained containing maleic acid. The temperature employed in step (a) is preferably 135‹ C. and pressure 500 mm. Hg. The maleic acid solution used as starting material may be obtained by washing the effluent of a catalytic oxidation reactor for hydrocarbons, such as benzene, with or without the previous condensation of part of the maleic anhydride.