Control of impurities in product glacial acetic acid of rhodium-catalyzed methanol carbonylation
OwnerMark O. Scates, G. Paull Torrenceinventors
Life of this patent
Estimating the term…
Abstract
The present invention relates to carbonylation of methanol, methyl acetate, dimethyl ether or mixtures thereof to produce glacial acetic acid, and more specifically to the manufacture of glacial acetic acid by the reaction of methanol, methyl acetate, dimethyl ether or mixtures thereof with carbon monoxide wherein the product glacial acetic acid contains low impurities.
Claims29
A product glacial acetic acid of a rhodium-catalyzed methanol carbonylation acetic acid manufacturing process characterized by the presence of total aldehyde in an amount greater than 2 ppm.
A method of controlling impurities in a rhodium-catalyzed methanol carbonylation process for the manufacture of acetic acid, comprising:
- a) reacting methanol with carbon monoxide in a liquid reaction medium in the presence of a Group VIII metal catalyst;
- b) maintaining in the reaction medium a water concentration of 0.5 to 14 wt %, an iodide salt providing an ionic iodide in the range of 2 to 20 wt %, 1 to 20 wt % methyl iodide and 0.5 to 30 wt % methyl acetate thereby an acetic acid is produced;
- and
- c) contacting the resulting acetic acid stream with a silver or mercury exchanged cation exchange resin at a temperature greater than 50° C.;
- d) whereby the resulting product glacial acetic acid comprises total aldehyde in an amount greater than 2 ppm.
Dependencies are inferred from the claim text.