Patent ID: 8088832

Claim:
A method of producing ethanol from syngas comprising: providing a syngas comprising carbon monoxide, hydrogen and carbon dioxide; removing a portion of carbon dioxide from the syngas to produce a reduced carbon dioxide syngas; converting the reduced carbon dioxide syngas in the presence of a catalyst to produce a mixture comprising methanol and carbon monoxide and hydrogen; producing a mixture comprising methyl acetate, hydrogen, methanol, acetic acid, and water from the mixture comprising methanol and carbon monoxide and hydrogen, by reacting the methanol and carbon monoxide in the presence of a promoter and a metal catalyst comprising a metal selected from the group consisting of iridium, rhodium, iron, cobalt, nickel, ruthenium, palladium, osmium, and platinum, and the promoter; distilling the hydrogen from the mixture of methyl acetate, hydrogen, methanol, acetic acid, and water by flash distillation to produce a mixture comprising methyl acetate, methanol, acetic acid and water, wherein the flash distilled hydrogen is subsequently used in the production of ethanol; separating the mixture comprising methyl acetate, methanol, acetic acid and water to produce a mixture comprising methyl acetate and methanol and at least one fraction selected from the group consisting of a promoter fraction, an acetic acid fraction, and a water fraction; and producing a mixture comprising ethanol by reacting the methyl acetate and methanol mixture with hydrogen in the presence of a hydrogenation catalyst.