1
Shivaji Sircar, John W Zondlo: Hydrogen purification by selective adsorption. Air Products and Chemicals, Richard A Dannells Jr, Barry Moyerman, E Eugene Innis, March 7, 1978: US04077779 (105 worldwide citation)

Hydrogen-containing gas mixtures are subjected to selective adsorption in a pressure swing cyclic system to remove carbon dioxide and/or hydrocarbon gases, obtaining high recovery of hydrogen at high purity. The system can also be employed for separation of methane from admixture with CO.sub.2.


2
Madhukar B Rao, Shivaji Sircar, Joseph M Abrardo, William F Baade: Hydrogen recovery by adsorbent membranes. Air Products and Chemicals, John M Fernbacher, James C Simmons, William F Marsh, October 11, 1994: US05354547 (97 worldwide citation)

A composite semipermeable membrane comprising microporous adsorbent material supported by a porous substrate is operated in series with a pressure swing adsorption (PSA) system and the PSA reject gas is used as a sweep gas to improve membrane performance. The integrated membrane-PSA system is partic ...


3
Shivaji Sircar, John W Zondlo: Fractionation of air by adsorption. Air Products and Chemicals, Richard A Dannells, Barry Moyerman, March 22, 1977: US04013429 (89 worldwide citation)

Ambient air, during an on-stream period, is passed serially through a pretreatment adsorbent bed removing moisture and carbon dioxide therefrom and the thus dried and purified air then passed through a main adsorbent bed selective for retention of nitrogen, the oxygen-rich effluent being collected i ...


4
Shivaji Sircar, Wilbur C Kratz: Removal of water and carbon dioxide from air. Air Products and Chemicals, E Eugene Innis, Ronald B Sherer, February 10, 1981: US04249915 (85 worldwide citation)

Moisture and CO.sub.2 are removed from atmospheric air by adsorption of these respectively in separate beds. The moisture laden bed is regenerated by pressure swing adsorption in a relatively short operating cycle while the CO.sub.2 -laden bed is regenerated thermally at considerably longer time int ...


5
Shivaji Sircar, Ravi Kumar, William R Koch, John VanSloun: Recovery of methane from land fill gas. Air Products and Chemicals, Geoffrey L Chase, William F Marsh, James C Simmons, September 13, 1988: US04770676 (74 worldwide citation)

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 swi ...


6
Madhukar B Rao, Shivaji Sircar, Joseph M Abrardo, William F Baade: Hydrocarbon fractionation by adsorbent membranes. Air Products and Chemicals, John M Fernbacher, James C Simmons, William F Marsh, July 26, 1994: US05332424 (71 worldwide citation)

A method is disclosed for separating a multicomponent gas mixture comprising at least three components into three product streams by use of adsorbent membrane zones operating in series. Each product is enriched in a different component based upon the relative strength of adsorption of each component ...


7
Shivaji Sircar: Regeneration of adsorbents. Air Products and Chemicals, Geoffrey L Chase, William F Marsh, James C Simmons, November 15, 1988: US04784672 (69 worldwide citation)

In the recovery of methane and carbon dioxide from landfill gas (LFG) a selective adsorption system is employed having a pretreat section operated in temperature swing adsorption mode (TSA) to remove water and trace hydrocarbon contaminants, in flow communication with a pressure swing adsorption sec ...


8
Shivaji Sircar: Gas seperation by rapid pressure swing adsorption. Air Products and Chemicals, Geoffrey L Chase, James C Simmons, William F Marsh, December 10, 1991: US05071449 (68 worldwide citation)

A rapid adiabatic pressure swing adsorption process with a total cycle time ranging from 6 to 60 seconds with feed being introduced into a single separation vessel having dual adsorption layers operated alternately by a pressurized continuous feed gas involving a continuous feed and two continuous p ...


9
Madhu Anand, Madhukar B Rao, Shivaji Sircar: Hydrogen recovery by adsorbent membranes. Air Products and Chemicals, John M Fernbacher, July 25, 1995: US05435836 (68 worldwide citation)

Recovery of hydrogen from hydrogen-containing gas mixtures by pressure swing adsorption is increased by utilizing an adsorbent membrane to concentrate hydrogen in the pressure swing adsorption reject gas and recycling the resulting hydrogen-enriched stream to the feed of the pressure swing adsorptio ...


10
Madhukar B Rao, Shivaji Sircar, Timothy C Golden: Gas separation by adsorbent membranes. Air Products and Chemicals, John M Fernbacher, James C Simmons, William F Marsh, April 14, 1992: US05104425 (62 worldwide citation)

Composite semipermeable membranes comprising porous adsorptive material supported by a porous substrate are disclosed for use in a process for the separation of multicomponent gas mixtures. In the process, one or more primary components adsorb within the pores of the adsorptive material and diffuse ...



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