Method of conversion of syngas using microorganism on hydrophilic membrane

A process for converting a feed gas comprising syngas and containing at least one of CO or a mixture of CO2 and H2 to a liquid product under anaerobic conditions and recovering the liquid product with a fermentation liquid, said process comprising:

• a) passing a seeding solution comprising the liquid of the seeding solution and a monoculture of anaerobic microorganisms into contact with the outside side surface of a hydrophilic hollow fiber membrane having a central lumen, draining the liquid of the seeding solution from the outside surface of membrane through the central lumen to immobilize the microorganisms and retaining immobilized microorganisms consisting essentially of the monoculture of anaerobic microorganisms on the outside surface of the membrane which serves as an exclusion surface to inhibit penetration of the microorganisms into the membrane;
• b) growing a biofilm comprising the immobilized microorganisms of the monoculture on the outside surface of the membrane by passing a feed gas comprising CO or a mixture of CO2 and H2 into contact with the monoculture of microorganisms on the outside surface of the membrane and permeating a fermentation liquid from the outside surface through the membrane and into contact with the immobilized microorganisms wherein the outside surface of the membrane serves as an exclusion surface to inhibit penetration of the biofilm to no more than 10 μm beyond the membrane surface into the membrane and the feed gas has an oxygen concentration of less than 1000 ppm;
• c) producing liquid products under autotrophic conditions by contacting the biofilm with the feed gas, permeating the fermentation liquid from the lumen of the membrane through the membrane and into contact with the biofilm, and permeating liquid products from the biofilm across the membrane and into the fermentation liquid, wherein a liquid retention chamber retains the fermentation liquid, and the fermentation liquid has a redox potential of less than −200 mV;
• d) collecting fermentation liquid containing liquid products from the liquid retention chamber to recover liquid products from the process;
• and,
• e) periodically increasing the pressure of the fermentation liquid to create liquid flow from the central lumen through the membrane and to the outside of the membrane to purge microorganisms from the membrane.

A process for converting a feed gas comprising syngas and containing at least one of CO or a mixture of CO2 and H2 to a liquid product under anaerobic conditions and recovering the liquid product with a fermentation liquid, said process comprising:

• a) passing a seeding solution comprising a monoculture of microorganisms to a feed gas chamber that houses a plurality of hydrophilic hollow fiber membranes and into contact with the outside side surface of hollow fiber membrane, raising the pressure on the outside of the membranes relative to the lumens to drain the liquid from feed gas chamber through a central lumen of the hollow fibers to immobilize the microorganisms and retaining immobilized microorganisms consisting essentially of the monoculture of an anaerobic microorganism on the outside surface of the membrane which has pores therein of a size of 0.5 μm or less for inhibiting penetration of the microorganisms into the pores such that the membrane surface provides an exclusion surface to inhibit penetration of the microorganisms into the membrane;
• b) growing a biofilm comprising the immobilized microorganisms of the monoculture on the outside surface of the membrane by passing a feed gas comprising CO or a mixture of CO2 and H2 into contact with the monoculture of microorganisms on the outside surface of the membrane and permeating a fermentation liquid from the outside surface through the membrane and into contact with the immobilized microorganisms wherein the outside surface of the membrane serves as an exclusion surface to inhibit penetration of the biofilm to no more than 10 μm beyond the membrane surface into the membrane and the feed gas has an oxygen concentration of less than 1000 ppm;
• c) producing liquid products under autotrophic conditions by contacting the biofilm with the feed gas, permeating the fermentation liquid from the lumen of the membrane through the membrane and into contact with the biofilm, and permeating liquid products from the biofilm across the membrane and into the fermentation liquid, wherein a liquid retention chamber retains the fermentation liquid, and the fermentation liquid has a redox potential of less than −200 mV;
• d) collecting fermentation liquid containing liquid products from the liquid retention chamber to recover liquid products from the process;
• and,
• e) periodically increasing the pressure of the fermentation liquid to create liquid flow from the central lumen through the membrane and to the outside of the membrane to purge microorganisms from the membrane.