Patent ID: 7456326
Filing Date: 2008-11-25
Classification: C12P,Y02E

Abstract:
1. A method comprising (a) treating carbohydrate material to produce therefrom ethanol, moist byproduct solids, and a gaseous process stream of carbon dioxide, (b) feeding the moist byproduct solids and a compressed gaseous stream of carbon dioxide to a dryer, (c) heating and drying the moist solids in the dryer and recovering therefrom a gaseous stream of carbon dioxide which also comprises water vapor and organic contaminants, (d) compressing at least a portion of the gaseous stream recovered in step (c) and recycling it to said dryer in step (b), thereby forming a circulating gaseous stream of carbon dioxide-containing gas, (e) feeding at least a portion of said gaseous process stream of carbon dioxide produced in step (a) into said circuit, and (f) treating said circulating gaseous stream to remove water vapor and organic contaminants therefrom.