Chemisorption of Ethyl Acetate During Hydrogenation of Acetic Acid to Ethanol

A hydrogenation catalyst for converting a mixture comprising acetic acid and ethyl acetate to ethanol at a first temperature, the catalyst comprising a first metal or oxide thereof, a second metal or oxide thereof, and a third metal or oxide thereof, on a support, provided that the first metal is reduced after hydrogen treatment and the second and third metals are partly reduced after hydrogen treatment;

• the first metal or oxide thereof is selected from the group consisting of rhodium, rhenium, ruthenium, platinum, palladium, osmium, iridium and gold, and the second metal or oxide thereof is selected from the group consisting of copper, iron, cobalt, nickel, zinc, and molybdenum;
• the third metal or oxide thereof is selected from the group consisting of copper, molybdenum, tin, chromium, iron, cobalt, vanadium, palladium, platinum, lanthanum, cerium, manganese, ruthenium, rhenium, gold, and nickel and further wherein the third metal and the second metal are different than the first metal;
• and
• wherein the hydrogen treated catalyst has an ethyl acetate desorption peak at a second temperature that is greater than an ethyl acetate desorption peak at the first temperature.

A process for producing ethanol comprising:

• contacting a feed stream comprising acetic acid, ethyl acetate, and hydrogen at a reactor temperature from 125° C. to 350° C. with a hydrogenating catalyst comprising one or more active metals or oxide thereof on a support to form ethanol,
• wherein the support comprises tungsten or an oxide thereof;
• wherein the one or more active metals are selected from the group consisting of cobalt, copper, gold, iron, nickel, palladium, platinum, iridium, osmium, rhenium, rhodium, ruthenium, tin, zinc, lanthanum, cerium, manganese, chromium, vanadium, and molybdenum;
• and
• wherein the catalyst desorbs ethyl acetate, in the absence of hydrogen, at a second temperature that is greater than the first temperature.

A process for producing ethanol comprising:

• contacting a feed stream containing acetic acid, ethyl acetate, and hydrogen at a reactor temperature with a hydrogenating catalyst comprising a first metal or oxide thereof, a second metal or oxide thereof, and a third metal or oxide thereof, on a support, provided that the first metal is reduced after hydrogen treatment and the second and third metals are partly reduced after hydrogen treatment;
• the first metal or oxide thereof that is selected from the group consisting of rhodium, rhenium, ruthenium, platinum, palladium, osmium, iridium and gold, and the second metal or oxide thereof that is selected from the group consisting of copper, iron, cobalt, nickel, zinc, and molybdenum;
• the third metal or oxide thereof that is selected from the group consisting of copper, molybdenum, tin, chromium, iron, cobalt, vanadium, palladium, platinum, lanthanum, cerium, manganese, ruthenium, rhenium, gold, and nickel and further wherein the third metal and the second metal are different than the first metal;
• wherein the hydrogen treated catalyst has an ethyl acetate desorption peak to a second temperature greater than the first temperature;
• and
• wherein the support comprises tungsten or oxide thereof.

A process for producing ethanol comprising:

• passing a gaseous mixture comprising acetic acid, ethyl acetate, and hydrogen over a catalyst at a first temperature, the catalyst comprising one or more active metals on a support,
• wherein the one or more active metals are selected from the group consisting of cobalt, copper, gold, iron, nickel, palladium, platinum, iridium, osmium, rhenium, rhodium, ruthenium, tin, zinc, lanthanum, cerium, manganese, chromium, vanadium, and molybdenum;
• and
• wherein the catalyst has an ethyl acetate adsorption capacity (Type III+IV) that is from 30 to 70 μmol/gcat at a second temperature that is greater than the first temperature.