Water vapor permeation through cellulose acetate membranes and its impact upon membrane separation performance for natural gas purification
GQ Chen, S Kanehashi, CM Doherty, AJ Hill, SE Kentish
Journal of Membrane Science | Elsevier | Published : 2015
Abstract Cellulose acetate is the predominant material used in membrane separation of acid gases from natural gas and biogas. However, the sensitivity of these membranes to water vapor is not well understood. In this work, flat-sheet membranes of two different degrees of acetylation, were exposed to both dry and humidified CH4 and CO2/CH4 mixtures. Positron Annihilation Lifetime Spectroscopy experiments showed that the number of free volume elements decreased as water concentration increased, indicating pore filling effects. The size of the free volume elements declined initially, followed by an increasing trend at vapor partial pressures greater than 2.5 kPa, indicating polymer swelling. Ga..View full abstract
Awarded by ARC DECRA
The authors would like to thank the Particulate Fluids Processing Centre (PFPC), a Special Research Centre of the Australian Research Council for access to equipment. Funding for this project is provided by the Cooperative Research Centres (CRC), Australian Government Department of Industry Australia. CMD and AJH acknowledge the support of CSIRO's Office of the Chief Executive Science Leader program and CMD would like to acknowledge the ARC DECRA support (DE140101359). The authors would also like to thank Daicel Corporation, Japan for providing the cellulose acetate polymers for this work. Mr Hiep Lit assisted with the membrane density measurements and this assistance is gratefully acknowledged.