Management of ethanol concentration during syngas fermentation

• Main Authors: SENARATNE RYAN, LIU SONG
• Format: Patent
• Language: English
• Published: 24.06.2016
• Subjects: BEER; BIOCHEMISTRY; CHEMISTRY; COMPOSITIONS OR TEST PAPERS THEREFOR; CONDITION-RESPONSIVE CONTROL IN MICROBIOLOGICAL ORENZYMOLOGICAL PROCESSES; ENZYMOLOGY; FERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIREDCHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERSFROM A RACEMIC MIXTURE; MEASURING OR TESTING PROCESSES INVOLVING ENZYMES, NUCLEICACIDS OR MICROORGANISMS; METALLURGY; MICROBIOLOGY; MUTATION OR GENETIC ENGINEERING; PROCESSES OF PREPARING SUCH COMPOSITIONS; SPIRITS; VINEGAR; WINE

A process for fermentation of syngas is disclosed where syngas is contacted with a medium inoculated with acetogenic bacteria and having a cell density of at least about 0.3 grams per litre. The syngas is fermented to convert CO to ethanol. Cells and medium are removed from the fermentation upon reaching an ethanol concentration of more than about 10 g/L in the fermentation. The removed cells and medium are separated to provide concentrated cells and permeate. Ethanol is separated from the permeate to provide ethanol and a reduced ethanol aqueous stream having less than about 5 weight % alcohol; and the reduced ethanol aqueous stream is provided having less than about 5 weight % alcohol to the fermentation. A ratio of a rate of providing the reduced ethanol aqueous stream to the fermentation to a rate of removing the cells and medium from the fermentation is about 5 to about 15 and an ethanol concentration of more than about 10 g/L is maintained in the fermentation.