Stacked Array Bioreactor for Conversion of Syngas Components to Liquid Products

A modular membrane bioreactor for anaerobic conversion of syngas into liquid products comprising:

• a plurality of membrane modules stacked in an axial direction, each membrane module having a plurality of hollow fibers, each of the plurality of hollow fibers comprising an asymmetric membrane wall defining biopores on an outer layer of the hollow fiber for retaining a porous biolayer about an outer surface of a hollow fiber wall of the hollow fiber and a less permeable hydration layer around a hollow fiber lumen of the hollow fiber;
• a membrane vessel for retaining the membrane modules surrounded by a process gas containing at least one of CO or a mixture of CO2 and H2 at a pressure above atmospheric pressure for the formation of the porous biolayer containing microorganisms selected from the group consisting of Clostridium ragsdalei, Butyribacterium methylotrophicum, Clostridium ljungdahlii, Clostridium carboxidivorans, and combinations thereof about the outer surface of the hollow fiber wall and for the production of a liquid product selected from the group consisting of ethanol, n-butanol, hexanol, acetic acid, butyric acid, and combinations thereof by interaction of microorganisms with the process gas and process liquid that permeates across the hollow fiber wall;
• a liquid supply conduit for serially communicating a process liquid with the hollow fiber lumens of the hollow fibers for permeation of water and nutrients to the biolayer and permeation of the liquid product from the biolayer into admixture with the process liquid;
• a liquid recovery conduit in communication with the hollow fiber lumens to recover the process liquid containing the liquid product from the membrane vessel;
• a gas supply conduit for supplying the process gas containing at least one of CO or a mixture of CO2 and H2 to the interior of the membrane vessel;
• and
• a product recovery system operably connected to receive the process liquid from the liquid recovery conduit, to separate the liquid product from the process liquid, and to return the process liquid to the membrane vessel.

A bioreaction method comprising:

• retaining a process gas in a membrane vessel under anaerobic conditions;
• maintaining multiple membrane modules in the process gas as a stacked arrangement, the membrane modules having a plurality of hollow fibers, each of the plurality of hollow fibers having a hollow fiber wall defining a hollow fiber lumen and an outer surface;
• growing a biolayer containing microorganisms about the outer surface of the hollow fibers by using at least a portion of the process gas as feed to the microorganisms;
• and
• passing a process liquid into the hollow fiber lumens and circulating process liquid from the hollow fiber lumens across the hollow fiber walls to interact with the biolayer and generate a liquid product that mixes with the process liquid.