Abstract: A method is disclosed for the thermal regeneration of an adsorbent which contains adsorbed components which can react with and damage the adsorbent at regeneration temperatures. The method comprises passing a hot regeneration gas through a bed of the adsorbent at a sufficiently high flow rate such that the residence time and reaction of the desorbed components in the adsorbent bed are minimized. For removing water from CaX or SrX zeolites, the flow of nitrogen regeneration gas is controlled so that the nitrogen gas residence time in the bed is less than one second.

Abstract: High yields of hydrogen of high purity are obtained from a methane-rich gas stream, such as natural gas, by a particular combination of operations wherein the methane-rich gas undergoes primary steam reforming under less severe operating conditions including lower steam to carbon ratio, supplemented by secondary reforming with oxygen, the obtained hydrogen is separated from accompanying carbon dioxide in the reformer effluent by a special five step pressure swing adsorption sequence having the steps of selective CO.sub.2 adsorption at superatmospheric pressure, rinsing with desorbed carbon dioxide, depressuring and then evacuating without additional rinsing, followed by repressuring the bed with part of the recovered pure hydrogen.

Abstract: High purity methane and carbon dioxide are recovered from landfill gas in an integrated multi-column adsorption system having a temperature swing adsorption section (TSA) for pretreatment of the crude landfill gas to remove trace impurities therefrom, the thus cleaned gas being fed to a pressure swing adsorption section (PSA) for bulk separation of CO.sub.2 from methane. Regeneration of the impurity-laden adsorbent bed of the TSA section is carried out using part of the CO.sub.2 product gas recovered from the PSA section which gas is heated to thermal regeneration temperature.

Abstract: The gaseous effluent from oxidation of organic material with oxygen-rich gas, which effluent contains CO.sub.2 (and possible CO) and unreacted residual oxygen, is compressed and charged to a PSA system for selective removal of the CO.sub.x, the thus purified oxygen-rich product from the PSA system being recycled to the oxidation reaction. In the PSA system comprised of a plurality of adsorption columns operated in parallel, each column in turn undergoes the steps of: (1) selective adsorption of CO.sub.2 from the feed gas; (2) depressuring to near ambient level; (3) purging with air to remove sorbed CO.sub.2 ; and (4) repressuring with part of the recycled effluent from step (1).

Abstract: In a cyclic VSA system for air fractionation by selective adsorption of nitrogen from the feed air during an on-stream adsorption period in said cycle in which period an oxygen-enriched primary effluent discharged from the adsorption column is collected in a surge vessel, the duration of the on stream adsorption step is automatically controlled by a sensing device monitoring inventory of gas collected in said surge vessel. In an alternative embodiment the adsorbed nitrogen is withdrawn by vacuum desorption of the column and collected in a second surge vessel, from which second vessel a portion of the nitrogen is subsequently withdrawn for use in rinsing the nitrogen laden column, said second surge vessel being likewise equipped with inventory monitoring means operative for automatically controlling the extent of the rinsing step.