Abstract: An adsorptive separation process of the present invention relates to a process for separating hydrogen and/or helium by a pressure swing adsorption process using four or more adsorbent beds. Each adsorbent bed manipulates the individual steps of adsorption, equal depressurization, cocurrent depressurization, countercurrent depressurization, purging, equal pressurization, product pressurization and raw gas pressurization while sequentially switching them and carries out the raw gas pressurization step for applying pressure with raw gas as the final step for pressuring the adsorbent bed to the adsorbent pressure. Accordingly, a variation in pressure and flow rate can be suppressed, product can be attained stably, and the amount of product can be increased.

Abstract: The present invention relates to a steam reforming method of methanol for obtaining hydrogen gas and a system therefor. The present method and present system utilizes a heat transfer medium for regulating the temperature at each step of the process. By optimizing the flow so that the heat transfer medium circulate through the system as heat-exchanging with reactant at each step, temperature of the reactant is regulated at a desirable temperature for proceeding the reaction. Temperature of the decomposition process and the conversion process of methanol is independently regulated.

Abstract: A nitrogen production method wherein air is compressed, is removed of water and carbon dioxide contained therein, and is simultaneously cooled to a temperature close to the liquefying point, and the resultant cleaned and cooled air is fed into a rectifying column for rectification so that high purity nitrogen is withdrawn from the rectifying column overhead; and wherein the oxygen-enriched liquid air withdrawn from the rectifying column bottom is expanded and fed into a condensation step wherein it becomes a source of reflux producing cold in the above-mentioned rectifying column, and then a cold is produced by adiabatically expanding the vaporized gas, after which heat exchange with raw air is performed.

Abstract: A process for recovering argon in which a crude argon column is supplied with an argon feed gas containing a larger proportion of oxygen from a double rectifier and is cooled at its head portion with or without liquid air from a sump of the lower column of the double rectifier for producing a reflux of argon in the crude argon column. In the process, argon gas is compressed to a pressure sufficient for evaporating liquid oxygen fed from a condenser of the double rectifier, is then precooled in a heat exchanger, and thereafter liquefied by heat exchange with the liquid oxygen. Then the head portion of the crude argon column is cooled with the liquefied argon, which is then returned in a gaseous state for further compression to thereby circulate the argon gas.