MICROPOROUS HOLLOW-FIBER MEMBRANE MODULES AS GAS-LIQUID CONTACTORS .2. MASS-TRANSFER WITH CHEMICAL-REACTION

Absorption determined by mass transfer in the liquid is described well with the Graetz-Leveque equation adapted from heat transfer. The infl uence of a chemical reaction on the mass transfer was simulated with a numerical model and tested on the absorption Of CO2 in a hydroxide so lution. Absorption determined by mass transfer in the gas phase and th e pores of the membrane was also analysed experimentally and numerical ly. It was found that the gas phase concentration profile is establish ed at a very short distance from the entrance of the fibre. This resul ts in a constant Sherwood number along the fibre. A module coated with a very thin silicone rubber layer showed absorption rates comparable to the uncoated membranes. If absorption liquids are used which wet th e membranes, resulting in leaky membranes, such a coating can enlarge the application of microporous hollow fibre membrane module.