This paper explores the use of microporous hollow fibers as Structured packing for a distillation column of propylene-propane. The actual column, which is less than 0.4 m long, yields more than 8% enrichment of propylene from a 30% propane/70% propylene mixture. It has an HTU as low as 0.1 m and an overall mass transfer coefficient of about 10(-4) m/s with the resistance to mass transfer mainly coming from the vapor phase. The low HTU is due to the high mass transfer area per unit Volume. over 1100 in m(2)/m(3). The results begin to explore the use of hollow fibers as packing for a practical distillation. (c) 2005 Elsevier B.V. All rights reserved.