Patent ID: 6551805
Filing Date: 2003-04-22
Classification: C01B

Abstract:
A method for producing carbon dioxide comprising the following steps:(A) providing an oxidant fluid containing an oxygen concentration of at least 40 mole percent to a fermentation broth comprising one or more carbonaceous species; (B) employing oxygen from the oxidant fluid to promote microbial growth within the fermentation broth, carrying out fermentation within the fermentation broth, and producing carbon dioxide within the fermentation broth in a fermentation vessel; (C) passing a fermentation broth stream out from the fermentation vessel, through a heat exchanger, and then back into the fermentation vessel in a recirculation loop; (D) bubbling carbon dioxide out from the fermentation broth to form a gas mixture having a carbon dioxide concentration of at least 97.5 mole percent; and (E) recovering said gas mixture as product carbon dioxide, wherein said oxidant fluid is provided to the fermentation broth at a flow rate such that the amount of oxygen provided to the fermentation broth is not more than 5 weight percent of the amount of carbon dioxide produced.