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.

Mobile plant for the valorization of gaseous effluents derived from alcohol fermentation comprising:

• a unit for the production of bicarbonate, said unit being divided into at least two compartments disposed successively in series, and said unit comprising an injection point for compressed gas at the lower part of the first compartment, a point for removal of an aqueous suspension in said first compartment and an injection point for aqueous solution in the last compartment, means of counter-flow circulation for gas and for liquid between each successive compartment;
• a means for injecting a compressed gaseous effluent connected to said injection point for gases of said first compartment and adapted to being connected detachably to a point of extraction of the gas effluents from an alcohol fermentation bioreactor, said means for injecting a compressed gas effluent comprising a compressor;
• a storage tank for an aqueous solution of alkaline carbonate;
• a means for injecting aqueous solution connected to said storage tank and said injection point for aqueous solution in the last compartment;
• and
• a means of removal and filtration connected to said point of removal of aqueous suspension from said first compartment.