Patent ID: 8017384
Filing Date: 2011-09-13
Classification: C12M,C12P

Abstract:
1. A modular membrane bioreactor for anaerobic conversion of gas into liquid products comprising: a plurality of membrane modules having a plurality of hollow fibers packed across a cross sectional area of the membrane module in a direction transverse to an axis of the membrane module that extends in an axial direction, wherein said modules are stacked in said axial direction and the length of the hollow fibers extend in the axial direction of module stacking; each of the plurality of hollow fibers in the modules have a gas permeable hollow fiber wall defining a hollow fiber lumen and an outer surface and the fibers are potted at each end of the module to provide potted ends opposite axial ends of each module; a membrane vessel for retaining the plurality of membrane modules axially aligned within the vessel in said axial direction and at least partially submerged in a process liquid and isolated from the ambient atmosphere, the membrane vessel having a vessel cross sectional area perpendicular to the axis of the membrane vessel of no more than 1.5 times the cross sectional area of the membrane module and an inner diameter greater than the exterior diameter of the membrane modules to space the membrane vessel apart from the membrane modules; a gas inlet at one axial end of each module adapted to supply a process gas to the lumens of the hollow fibers and a gas outlet at an axial end of the module opposite the gas inlet to withdraw process gas that together provide process gas flow through the lumens of the hollow fibers in the module; a liquid inlet defined at least in part by one of said potted ends of each module to supply a process liquid to the hollow fibers and a liquid outlet defined at least in part by the potted end of the module opposite the liquid inlet and adapted to withdraw process liquid from the hollow fibers; a peripheral flow path at least on end of each module defined about the periphery of its potted end and extending about the periphery of the potted end and adapted to provide liquid flow between the potted end of the module and the wall of the vessel retaining the modules, said peripheral flow path providing one of said liquid inlet or said liquid outlet for supplying or withdrawing liquid to or from the outside of the hollow fibers; and, a gas supply conduit operably connected to the gas inlet for supplying a process gas to the hollow fiber lumens that enables the formation of a biofilm on the outer surface of the hollow fiber wall by interaction of microorganisms with the process gas and the production of a liquid product that mixes with the process liquid.