Gas permeation properties of 1-hexyl-3-methylimidazolium chloride supported liquid membranes

摘要

Hydrogen and carbon monoxide are valuable gases of particular interest in the synthesis routes of a wide number of major chemical products; furthermore, H2 is seen as a promising clean energy carrier and its application on fuel cells is in focus of research, however, highly pure H2 is needed to avoid poisoning. The use of membrane technology is an important strategy on the way of process intensification in order to reduce the equipment size, energy utilization and production costs of conventional gas separation units, e.g., cryogenic distillation and adsorption processes [1]. The main applications in which H2-permeable membranes for gas separations are presently applied are: H2 recovery from ammonia purge gas streams, H2/methane separation in refinery off-gas, and H2/CO ratio adjustment in oxo-chemical synthesis plants. Another H2 and CO source is the tail gas waste stream generated in the reactor of carbon black manufacturing industry, where these gases are present at concentrations up to 20 %vol. (on a dry basis) together with nitrogen (60%vol.), carbon dioxide (5%vol.) and other compounds in minor quantities [2]. The recovery of H2 and CO from this source will lead to economic savings and a smaller environmental footprint.