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AssigneeINEOS Phenol GmbH & Co. KG
InventorsMichael Sakuth, Uwe Tanger, Markus Weber
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The invention relates to a process for the preparation of cumene by reacting isopropanol or a mixture of isopropanol and propene with benzene in presence of a β-zeolite catalyst having a SiO2/Al2O3 molar ratio greater than 10:1 that can be integrated in a process for preparing phenol, which comprises the steps I. preparation of cumene as described above, II. oxidation of cumene to cumene hydroperoxide, III. acid-catalyzed cleavage of cumene hydroperoxide to give phenol and acetone and IV. hydrogenation of acetone to form isopropanol. In the reaction of isopropanol with benzene, propene is formed by dehydration of isopropanol simultaneously with the alkylation of benzene to cumene by means of isopropanol and the propene formed is likewise used for the alkylation of benzene to cumene. Formation of n-propylbenzene in this process step according to the invention is barely observed or is in the range below 150 wppm. The β-zeolite catalyst having a SiO2/Al2O3 molar ratio greater than 10:1 exhibits an increased activity in the alkylation of benzene and leads to a higher selectivity in the alkylation, so that the yield in the overall process for preparing phenol can be improved compared to conventional processes.
A process for the preparation of cumene by reacting isopropanol or a mixture of isopropanol and propene with benzene in presence of a β-zeolite catalyst having a SiO2/Al2O3 molar ratio greater than 10:1, wherein the acidity of the catalyst is modified by surface addition of water.
The process of any of the preceding claims, wherein the water content of the total feed stream to the reactor does not exceed 5 wt.-% based on the weight of the total feed stream.
The process of any of the preceding claims, wherein the molar ratio of benzene to isopropanol in the feed stream to the reactor is greater than 1:1.
The process of any of the preceding claims, wherein the reaction is carried out at a temperature of from 100 to 300° C.
The process of any of the preceding claims, wherein the reaction is carried out at a pressure of from 10 to 100 bar abs.
The process of any of the preceding claims, wherein the reaction is carried out in a stirred tank reactor, a trickle-bed reactor or a fixed-bed reactor.
The process of any of the preceding claims, wherein the reaction mixture is, after leaving the reactor, separated into an aqueous phase and an organic phase by liquid/liquid phase separation.
The process of any of the preceding claims, wherein the reaction mixture has an n-propylbenzene concentration of less than 300 wppm, preferably less than 150 wppm.
A process for the hydrogenation of acetone to isopropanol in at least two process stages, wherein the acetone used is crude acetone.
Dependencies are inferred from the claim text.