Membrane supported bioreactor for conversion of syngas components to liquid products

摘要

Ethanol and other liquid products are produced by contacting syngas components such as CO or a mixture of CO2 and H2 with a surface of a membrane under anaerobic conditions and transferring these components into contact with a biofilm on the opposite side of the membrane. These steps provide a stable system for producing liquid products such as ethanol, butanol and other chemicals. The gas fed on the membrane's gas contact side transports through the membrane to form a biofilm of anaerobic microorganisms that converted the syngas to desired liquid products. The system can sustain production with a variety of microorganisms and membrane configurations.

主权项

1. A process for converting a feed gas containing at least one of CO or a mixture of CO2 and H2 under anaerobic conditions to a liquid product comprising at least one of ethanol, propanol, n-butanol, acetic acid, propionic acid and butyric acid:
a) passing a feed gas comprising a mixture of at least one of CO or a mixture of CO2 and H2 under anaerobic conditions to a gas contacting side of a bio-support membrane for transferring the feed gas across the membrane to a biofilm support side of the bio support membrane; b) circulating a fermentation liquid on the biofilm support side of the bio-support membrane, the fermentation liquid having a redox potential of less than −200 mV; c) maintaining a biofilm consisting essentially of anaerobic microorganisms on the biofilm support side of the bio-support membrane to convert at least a portion of the feed gas components to a liquid product comprising at least one of ethanol, propanol, n-butanol, acetic acid, propionic acid and butyric acid; d) maintaining a pressure differential across the bio-support membrane that avoids the formation of bubbles in the fermentation liquid and prevents wetting of the bio-support membrane on the gas contacting side of the bio-support membrane; and, e) recovering a liquid product from the fermentation liquid.