Novel Zeolite Membranes for Energy-Efficient Air Dehumidification and Conditioning

Traditional vapor compression air conditioners have very high power consumption for cooling of hot and humid air due to condensation of a large amount of water inside the cooler. We have developed a novel zeolite membrane supported on a thin (~50 micrometer thick) porous metal sheet to remove water vapor from an incoming humid air stream without changing its temperature, i.e., through vapor-phase membrane separation. The membrane dehumidifier reduces air humidity levels well below its due point under the cooling conditions so that only sensible cooling occurs. In this way, the energy consumption for air conditioning in hot and humid climate can be reduced by 50%. The high permeance and high H2O/air selectivity are critical performance parameters. Compared to previous membranes reported in the literature, our membrane exhibits a high H2O/air separation factor (> 100), a permeation flux about 2 or 3 orders of magnitude higher than the literature result, and excellent stability. This presentation will provide systematic discussion on impacts of membrane separation conditions, such as temperature, feed air humidity, and permeate pressure, on the membrane separation performances. The new membrane technology has great potential to be developed as a commercially-viable membrane dehumidifier by obtaining exceptional membrane separation performances and substantially reducing the zeolite membrane fabrication cost at the same time.