Method for preparing acrylic acid from propane and propylene

摘要

The application concerns a process comprising: (A) contacting a gas comprising oxygen, propane and propylene with at least one catalyst under reaction conditions sufficient to at least partially convert the propylene into a final product comprising acrylic acid; (B) feeding said final product to a separation column, in which the final product is split into a liquid stream, which is rich in acrylic acid, and a gaseous by-product stream comprising propane and propylene in a volume ratio of from 99.9:0.1 to 95:5; (C) contacting the gaseous by-product stream with oxygen in the presence of a catalyst under reaction conditions sufficient to at least partially convert propane to acrylic acid.

主权项

1. A process comprising:
(A) contacting a gas comprising oxygen, propane and propylene with at least one catalyst under reaction conditions sufficient to at least partially convert the propylene into a final product comprising acrylic acid; wherein step (A) comprises: (a1) contacting the gas with a first catalyst under reaction conditions sufficient to at least partially convert the propylene into acrolein and to produce a gas phase intermediate product comprising acrolein; and (a2) contacting at least part of the acrolein-containing gas phase intermediate product of step (a1) with oxygen and a second catalyst under reaction conditions sufficient to at least partially convert the acrolein into a final product comprising acrylic acid; (B) feeding said final product to a separation column, in which the final product is split into a liquid stream, which is rich in acrylic acid, and a gaseous by-product stream comprising propane and propylene in a volume ratio of from 99.9:0.1 to 95:5; (C) contacting the gaseous by-product stream with oxygen in the presence of a Mo/V/Te/Nb mixed metal oxide catalyst in a finishing reactor under reaction conditions sufficient to at least partially convert propane to acrylic acid, wherein the feed gas to the finishing reactor comprises propane in an amount between 0.1 vol % and 8 vol %, oxygen in an amount between 1 vol % and 50 vol %, and water in an amount between 1 vol % and 50 vol %, based upon the total volume of the gaseous by-product stream.