A process for making a modified, mesoporous activated carbon material from waste oil fly ash. The process involves a physicochemical treatment of a raw waste oil fly ash sample, where the sample is initially refluxed in an acid solution, then activated at about 1000 C. and in the presence of carbon dioxide. The activated carbon may be further functionalized with carboxylic and/or amine groups by refluxing the activated carbon in a second acid solution and/or an ammonia solution. The activated carbon, as prepared, has a BET surface area of 30-400 m.sup.2/g, a total pore volume of 0.25-0.50 cm.sup.3/g and an average pore size of 40-100 . A method for removing hydrogen sulfide from natural gas with the modified activated carbon is also provided.

A process for making a modified, mesoporous activated carbon material from waste oil fly ash. The process involves a physicochemical treatment of a raw waste oil fly ash sample, where the sample is initially refluxed in an acid solution, then activated at about 1000 C. and in the presence of carbon dioxide. The activated carbon may be further functionalized with carboxylic and/or amine groups by refluxing the activated carbon in a second acid solution and/or an ammonia solution. The activated carbon, as prepared, has a BET surface area of 30-400 m.sup.2/g, a total pore volume of 0.25-0.50 cm.sup.3/g and an average pore size of 40-100 . A method for removing hydrogen sulfide from natural gas with the modified activated carbon is also provided.

A method of removing impurities from a gas including the steps of removing impurities from biogas comprising at least one adsorbents via a process vessel or reactor, directing the purified gas to an device to generate power and/or heat, regenerating the saturated adsorption media with the waste heat recovered from the engine exhaust and directing the regeneration gas (hot air or engine exhaust) to flare, engine exhaust stack, or atmosphere.

Systems and methods for using pressure swing adsorption to separate and/or capture resulting emissions are provided. A stream of recycled exhaust gas is passed into a first swing adsorption reactor comprising a first adsorbent material which adsorbs CO.sub.2. An enriched N.sub.2 stream is recovered from a forward end of the first swing adsorption reactor. The pressure in the first swing adsorption reactor is reduced. The first swing adsorption reactor is purged with a portion of the first N.sub.2 stream recovered from the first swing adsorption reactor. The first purge output is passed to a second swing adsorption reactor comprising a second adsorbent material which adsorbs CO.sub.2. A second N.sub.2 stream is recovered from the second swing adsorption reactor. The pressure in the second swing adsorption reactor is reduced. The second swing adsorption reactor is purged with a steam purge.

Systems and methods are provided for combined cycle power generation while reducing or mitigating emissions during power generation. Recycled exhaust gas from a molten carbonate fuel cell power generation reaction can be separated by using a swing adsorption process so as to generate a high purity CO.sub.2 stream while reducing or minimizing the energy required for the separation and without having to reduce the temperature of the exhaust gas. A high temperature adsorption reactor adsorbs the CO.sub.2 and recovers H.sub.2 from an exhaust gas of a first molten carbonate fuel cell at a high temperature and at a low pressure. The reactor passes along the adsorbed CO.sub.2 to a cathode and the recovered H.sub.2 to an anode of a second molten carbonate fuel cell for further power generation. This can allow for improved energy recovery while also generating high purity streams of CO.sub.2 and H.sub.2.

A process for making a modified, mesoporous activated carbon material from waste oil fly ash. The process involves a physicochemical treatment of a raw waste oil fly ash sample, where the sample is initially refluxed in an acid solution, then activated at about 1000 C. and in the presence of carbon dioxide. The activated carbon may be further functionalized with carboxylic and/or amine groups by refluxing the activated carbon in a second acid solution and/or an ammonia solution. The activated carbon, as prepared, has a BET surface area of 30-400 m.sup.2/g, a total pore volume of 0.25-0.50 cm.sup.3/g and an average pore size of 40-100 . A method for removing hydrogen sulfide from natural gas with the modified activated carbon is also provided.

A continuous desulfurization process and process system are described for removal of reduced sulfur species at gas stream concentrations in a range of from about 5 to about 5000 ppmv, using fixed beds containing regenerable sorbents, and for regeneration of such regenerable sorbents. The desulfurization removes the reduced sulfur species of hydrogen sulfide, carbonyl sulfide, carbon disulfide, and/or thiols and disulfides with four or less carbon atoms, to ppbv concentrations. In specific disclosed implementations, regenerable metal oxide-based sorbents are integrated along with a functional and effective process to control the regeneration reaction and process while maintaining a stable dynamic sulfur capacity. A membrane-based process and system is described for producing regeneration and purge gas for the desulfurization.

A process for the providing a regenerant gas stream for a regenerable adsorbent used to remove water and hydrogen sulfide from a reactor effluent in a catalytic dehydrogenation process is described. The reactor effluent is compressed in a compressor to provide a compressed effluent. The compressed effluent may be treated to remove chlorides, and then passed to a dryer zone having a regenerable adsorbent. A regenerant gas stream is used to desorb the water and hydrogen sulfide and the spent regenerant stream may be passed to a cleaning zone having a sorbent configured to remove hydrogen sulfide from the spent regenerant stream. The cleaned regenerant gas stream may be recycled to the dryer zone to desorb and/or regenerate the regenerable adsorbent.

A process for generating a syngas from a CO.sub.2-rich and hydrocarbon-containing feed gas, wherein a CO.sub.2-rich and hydrocarbon-containing feed gas is provided and is reacted in a syngas generation step by means of partial oxidation or steam reforming to give an H.sub.2- and CO-comprising syngas. At least CO.sub.2 is removed from the feed gas in a scrubbing of the feed gas by means of a scrubbing medium, before the feed gas is fed to the syngas generation step.

Methods and apparatuses for separating CO.sub.2 and sulfur-containing compounds from a synthesis gas obtained from gasification of a carbonaceous feedstock. The primary separating steps are performed using a sour pressure swing adsorption (SPSA) system, followed by an acid gas enrichment system and a sulfur removal unit. The SPSA system includes multiple pressure equalization steps and a rinse step using a rinse gas that is supplied from a source other than directly from one of the adsorber beds of the SPSA system.