METHOD FOR PRODUCING ADSORBING AGENT FOR CARBON MOLECULAR SIEVE, CARBON MOLECULAR SIEVE OBTAINED BY SAID METHOD AND METHOD FOR SEPARATING GAS BY SELECTIVE ADSORPTION USING SAID MOLECULAR SIEVE

摘要

PURPOSE: To provide a process for making a modified carbon molecular sieve which is suitable for separating gases having different adsorption rates on the sieve. CONSTITUTION: A starting sieve support having a majority of micropores with an effective pore size of about 4.5-20 angstroms is modified with a two-step process, in which the sieve is contacted with two kinds of hydrocarbons having different concentrations. The conc. of the carbon-contg. compd. used in the first step is higher than that in the second step, so that the pore openings of the micropores of the support are narrowed successively in two distinct steps without filling the micropores themselves. Further, an improved carbon molecular sieve and the separation of gases such as oxygen from nitrogen by the use of this modified absorbent are also disclosed.