Oxygen Transfer in Membrane‐Ceramic Composite Materials For Immobilized‐Cell Monolithic Reactors

A novel bioreactor concept is described for facilitated gas‐liquid mass transfer, specifically oxygen supply, at low shear rates and low power input. The cross flow monolithic reactor is a single piece of ceramic consisting of continuous flow passages manifolded in a cross flow arrangement. Liquid medium circulates through the passages in one direction and gas circulates through the passages in an orthogonal direction; thus, the two streams are contacted across a large area of a porous ceramic, gas permeable membrane composite. A test cell was designed and used to measure the rate of oxygen transfer across such a composite. High oxygen transfer rates (6.62g O 2 × l −1 × hr −1 ), with minimal power requirements (estimated below 5 × 10 −3 watts/l reactor volume), were found. This corresponds to a transfer efficiency of greater than 1000 kg O 2 /kW · hr, orders of magnitude greater than the values reported by Serieys, et al. 14 due to the low flow rates and low pressure drops required in a cross flow monolith. This contacting configuration could be employed with highly aerobic, immobilized‐cell fermentations to enhance oxygen transfer rates with a parallel decrease of process power requirements.