JPH0217214B

PURPOSE:To enhance selective adsorption and separation performance, by mixing N-methylimidazole and furthermore phenols and/or anilines with copper compd. such as cuprous chloride and cuprous bromide and preparing the separation material of gas. CONSTITUTION:Selective absorbing liquid for gas is prepared with a reacted mixture obtained by mixing N-methylimidazole and furthermore phenols and/or anilines with at least one kind of copper compd. selected from among cuprous chloride, cuprous bromide, cuprous iodide and cuprous thiocyanate in a soln. Further a permselective membrane of gas is made by holding the above- mentioned reacted mixture on a supporting film thereof. The obtained reacted- mixture available for separation of gas can be favorably used mainly for the separation of carbon monoxide and for example, it is available for the separation of carbon monoxide from a gaseous mixture contg. carbon monoxide obtained by steam reforming of hydrocarbon such as natural gas and light naphtha.