Compositions for carboxylic acid production and methods for making and using same

Abstract

An alcohol such as methanol is reacted with carbon monoxide in a liquid reaction medium including a catalyst, an alkyl iodide such as methyl iodide, alkyl acetate such as methyl acetate in specified proportions, an additive, and an effective amount of water, where the additive increases an ionic character of the hydrogen iodide bond and the effective amount of water is sufficient to facilitate carboxylic acid release after carbonylation at the catalyst and to reduce anhydride formation. The present reaction system not only provides an acid product at water levels considerable below levels currently used, but also provides unexpected reaction rates and unexpected high catalyst stability.

Description

RELATED APPLICATIONS[0001]This application claims priority to and the benefit of U.S. Provisional Patent Application Ser. No. 61 / 133,398, filed Jun. 28, 2008.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]Embodiments of the present invention relate to a composition for carboxylic acid production and methods for making and using same.[0004]More particularly, embodiments of the present invention relate to a composition for carboxylic acid production and methods for making and using same, where the composition includes a metal catalyst, carbon monoxide, an alkanol, an iodine source, an additive providing hydrogen bonding to HI present in the reaction media, and optionally added water.[0005]2. Description of the Related Art[0006]Production of acetic acid via methanol carbonylation is an industrial process used on a global basis to produce billions of pounds of glacial acetic acid. The process as currently practiced commercially operates under relatively mild conditions ...

AI Technical Summary

Benefits of technology

[0011]Embodiments of the present invention relate to liquid reaction media for carbonylation of alcohols to carboxylic acids, where the media include a catalyst, an alcohol (ROH) or alcohol equivalents such as an alkyl acetate (AcOR), a source of iodide to form an alkyl iodide (RI), an effective amount of an additive, and optionally an effective amount of added water in the presence of carbon monoxide, where the media converts the alcohol to a carboxylic acid having one more carbon atom, the effective amount of the additive is sufficient to increase an ionic character of the hydrogen iodide bond produced during the carbonylation reaction, to reduce added water below levels currently used or eliminate added water and to improve catalyst stability and where the effective amount of added water is sufficient to facilitate carboxylic acid formation after carbonylation of the alcohol at the catalyst and to reduce anhydride formation.

Problems solved by technology

Catalyst stability is adversely affected by lower reactor water concentrations.

Another problem with the current processes is that catalyst stability and activity is lower than desired even with high reactor water concentrations.

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