SU1227630A1 - Method of producing maleic anhydride,maleic and fumaric acids - Google Patents

Description

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The invention relates to a method for producing maleic anhydride, maleic and fumaric acids, which can be used as monomers.

The aim of the invention is to increase the productivity of the process.

Example 1. A weighed portion of Hj PdBrJ equal to 0.684 g (1.56-10 mol) is transferred to the reactor and pour 1000 Mh of dry acetonitrile containing 5.63 g of hexafluoric ferric chloride (20, mol Fed, and 125 10 mol mol HjO ); 6.60 ml of 46.85% hydrobromic acid (56.7-10 mol HBr and 284-10 mol water). The total water content in the reaction solution is 0.73% by volume. Reactor thermostatic

with, 5 liters of reaction gas containing carbon monoxide, acetylene, and oxygen containing 2: 1: 0.5 in volume ratio of 2–1: 0.5 are blown through pre-passed through drying columns with CaCl1 and KOH, and the reaction is started. (Distilled water is injected into the reactor at a rate of 2.4 ml / h.

Lean anhydride is caught in a cooled receiver. A total of 176.0 g (1.76 mol) of maleic anhydride, which is 96.9 mol% 25 based on the absorbed acetylene, and 75.3 mol of maleic anhydride per 1 mol of catalyst per hour are obtained. The total yield of the reaction products is 1315 mol per 1 mol of catalyst and

The constant water content in the reaction solution is 0.73 vol.%. Reaction 30 98.3 mol% to absorbed acetylene. will cease after 15 hours (activity of the catalyst - 2-5. The process of conducting the analyzer is still high). 15 hours analogously to example 1. The reaction according to the analysis forms a- Parameters and results of the process with 15.02 g (0.150 mol) of maleic are presented in the table.

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 anhydride, 190.35 g (1.641 mol) of maleic acid and 3.01 g (0.260 mol) of fumaric acid.

The reaction products from the reaction solution are separated as follows.

The acetonitrile insoluble fumaric acid is isolated from the reaction solution by filtration. Then

At the end, the solvent was distilled off, and the distillations at 75 ° C distilled the maleic anhydride in solution as an azeotrope with acetonitrile, containing about 90% by weight of maleic anhydride. To completely remove the anhydride, the azeotrope was distilled off three times, adding 500-700 ml of acetonitrile to the dry residue. The dry residue is heated at 100 mm to 160 s. When this occurs, the dehydration of malic acid. Sublimate

Lean anhydride is caught in a cooled receiver. A total of 176.0 g (1.76 mol) of maleic anhydride, which is 96.9 mol% 25 based on the absorbed acetylene, and 75.3 mol of maleic anhydride per 1 mol of catalyst per hour are obtained. The total yield of the reaction products is 1315 mol per 1 mol of catalyst and

30 98.3 mol.% On absorbed acetylene. EXAMPLE 2-5. The process is carried out analogously to example 1. The parameters and results of the process are presented in the table.

Claims (1)

METHOD FOR PRODUCING MALEIC ANHYDRIDE, MALEIC AND FUMARIC ACID by reacting acetylene with carbon monoxide in the presence of oxygen, mineral acid and an oxidizing agent in an organic solvent in the presence of a complex of palladium bromide and lithium bromide as a catalyst at elevated temperature, atmospheric pressure and initial water content of 0, 2 0.8 vol.%, Ο · τ characterized in that, in order to increase the productivity of the process, it is conducted when water is supplied at a rate of 0.8-2.5 ml / h per 1 liter of catalyst solution. $ er KZ m s with about.