Sub-ambient temperature flue gas carbon dioxide capture via Matrimid super( registered ) hollow fiber membranes

Post-combustion carbon dioxide capture from power plant flue gas can play an important role in addressing current CO sub(2) emission concerns. Air Liquide is developing a sub-ambient membrane process to remove CO sub(2) from flue gas by careful process engineering and heat integration. We have successfully validated enhanced low temperature membrane performance reported by Air Liquide using Matrimid super( registered ) 5218. Asymmetric hollow fiber membranes with a CO sub(2)/N sub(2) selectivity of 209 and CO sub(2) permeance of 227 GPU at -50 degree C have been fabricated. The CO sub(2)/N sub(2) mixed gas transport properties at -20 degree C, -30 degree C, -40 degree C and -50 degree C are measured in an effort to better understand fundamentals of the enhanced low temperature performance. The permeance of CO sub(2) is minimally affected by temperature while comparatively large increases in CO sub(2)/N sub(2) selectivity are observed. The permeance of CO sub(2) increases with increasing pressure while minimal changes in CO sub(2)/N sub(2) selectivity are observed. High productivity and high selectivity are achievable with laboratory spun Matrimid super( registered ) hollow fibers. A hypothesis regarding the fiber's fused-nodular skin morphology is proposed and supported by confirmatory experiments.