Process for exploiting gas effluents from alcoholic fermentation

A method for valorization of gaseous effluents derived from an alcohol fermentation process comprising:

• fermenting alcohol in a bioreactor and producing fermented matter and a gaseous effluent containing carbon dioxide;
• extracting the gaseous effluent from said bioreactor;
• after extracting the gaseous effluent from the bioreactor, compressing the gaseous effluent to form a compressed gaseous effluent;
• producing a suspension of an alkaline bicarbonate in a bicarbonate production unit having at least first and second compartments disposed in series and comprising:
• introducing into the second compartment an aqueous solution containing dissolved alkaline carbonate;
• introducing the compressed gaseous effluent into the lower part of the first compartment;
• directing the compressed gaseous effluent through the first and second compartments where the compressed gaseous effluent contacts the aqueous solution which produces a gas stream depleted in carbon dioxide and wherein the aqueous solution becomes depleted in carbonate ions;
• precipitating an alkaline bicarbonate in the first compartment by reacting dissolved carbon dioxide with the dissolved alkaline carbonate of the aqueous solution to produce a suspension of insoluble alkaline bicarbonate;
• recovering the suspension of insoluble alkaline bicarbonate from the first compartment;
• and
• filtering or decanting the suspension of insoluble alkaline bicarbonate to produce a wet residue of alkaline bicarbonate and an aqueous phase.