US 2010/0168466 A1 · Integrated process for the production of vinyl acetate from acetic acid via acetaldehyde

Abstract

This invention provides an integrated multistep economical process for the production of vinyl acetate monomer (VAM) from acetic acid in the vapor phase. First, acetic acid is selectively hydrogenated over a hydrogenating catalyst composition to form acetaldehyde. Acetaldehyde so formed can be converted to ethylidene diacetate via reaction with acetic anhydride. In a subsequent step so formed ethylidene diacetate is thermally decomposed to form VAM and acetic acid. Alternatively, acetaldehyde formed in the first step can selectively be reacted with ketene to form VAM. In an embodiment of this invention reaction of acetic acid and hydrogen over platinum and iron supported on silica selectively produces acetaldehyde in a vapor phase at a temperature of about 300° C., which is selectively hydrogenated over platinum supported catalyst to form ethanol and dehydrated over NAFION catalyst to form ethylene at a temperature of about 185° C., which is mixed with molecular oxygen, acetic acid and reacted over a palladium/gold/potassium catalyst supported on titania to form VAM at a temperature of about 150° C. to 170° C.

Claims24

Dependent claims

A process for the production of vinyl acetate from acetic acid comprising:

a. contacting in a first reaction zone a feed stream containing acetic acid and hydrogen at an elevated temperature with a suitable hydrogenating catalyst including at least one metal selected from the group consisting of iron, copper, gold, platinum, palladium and ruthenium supported on a suitable catalyst support and optionally in combination with one or more metal catalysts selected from the group consisting of tin, aluminum, potassium, cobalt, molybdenum, tungsten and vanadium to form a first gaseous product stream comprising acetaldehyde;
b. enriching said first gaseous product stream with acetaldehyde at least 50 mole percent;
c. contacting in a second reaction zone said enriched first gaseous product stream obtained in step (b) at an elevated temperature with acetic anhydride to form a second gaseous product stream of ethylidene diacetate;
d. thermally decomposing in a third reaction zone said second gaseous product stream obtained in step (c) with a suitable acid catalyst to form a third gaseous product stream consisting essentially of vinyl acetate and acetic acid;
e. separating the vinyl acetate from said third gaseous product stream.

2 more elements

A process for the production of vinyl acetate from acetic acid comprising:

a. contacting in a first reaction zone a feed stream containing acetic acid and hydrogen at an elevated temperature with a suitable hydrogenating catalyst including at least one metal selected from the group consisting of iron, copper, gold, platinum, palladium and ruthenium supported on a suitable catalyst support and optionally in combination with one or more metal catalysts selected from the group consisting of tin, aluminum, potassium, cobalt, molybdenum, tungsten and vanadium to form a first gaseous product stream comprising acetaldehyde;
b. enriching said first gaseous product stream with acetaldehyde at least 50 mole percent;
c. contacting in a second reaction zone said enriched first gaseous product stream obtained in step (b) at an elevated temperature with acetic anhydride to form a second gaseous product stream of ethylidene diacetate;
d. contacting in a third reaction zone said second gaseous product stream obtained in step (c) at an elevated temperature with an acid catalyst chosen from aromatic sulfonic acids, sulfuric acid, and alkanesulfonic acids to form a third gaseous product comprising a mixture of vinyl acetate and acetic acid;
and
e. separating the vinyl acetate from said third gaseous product stream.

3 more elements

Dependencies are inferred from the claim text.

Integrated process for the production of vinyl acetate from acetic acid via acetaldehyde

Life of this patent

Integrated process for the production of vinyl acetate from acetic acid via acetaldehyde

Life of this patent

Abstract

Claims24