Methods and systems for continuous pressure swing adsorption separation of a pressurized feed gas stream, the method including separating hydrocarbons heavier than methane from the pressurized feed gas stream to produce at least two product streams, a first product stream being substantially pure methane, and a second product stream being substantially comprised of components with a greater molecular weight than methane.

Systems and methods are provided for separating oxygen from air using a sorption/desorption cycle that includes a reduced or minimized difference between the maximum and minimum pressures involved in the sorption/desorption cycle. The reduced or minimized difference in pressures can be achieved in part by using valves that can allow for commercial scale flow rates while avoiding large pressure drops for flows passing through the valves. A rotary wheel adsorbent is an example of a system that can allow for a sorption/desorption cycle with reduced and/or minimized pressure drops across valves associated with the process. Stationary adsorbent beds can also be used in combination with commercially available valves that have reduced and/or minimized pressure drops.

A portable pressure swing adsorption method and system for low flow rate gas processing. A method of processing of hydrocarbon gas includes feeding hydrocarbon gas through a first adsorption bed of a pressure swing adsorption system, recovering light product from the first adsorption bed during the feed time, obtaining heavy product from a second adsorption bed during the feed time, wherein the second adsorption bed depressurizes to about vacuum during the feed time, compressing the heavy product to obtain natural gas liquid and vapor, sending a volume of reflux gas through the first adsorption bed after the feed time to obtain additional light product, and adjusting the feed flowrate, the feed time, or the volume of reflux gas based on a gross heating value of the feed gas, wherein adjusting the volume of reflux gas includes combining NGL storage tank vapor with the reflux gas.

A method for producing oxygen by adsorbing a stream of atmospheric air, using four VPSA, one air compressor and two vacuum pumps, each adsorber undergoing a single pressure cycle including the following steps: a) producing a first stream of gas having an oxygen content T1 while loading the adsorber of the stream of atmospheric air upstream; b) producing a second stream of gas including an oxygen content T2<T1: c) producing a third stream of gas including an oxygen content T3<T2<T1 while simultaneously extracting a nitrogen-enriched residual stream; d) eluting the adsorber, from which the three streams of gas produced in steps a), b), and c) are taken with the second stream of gas produced in step b); e) repressurizing the adsorber consecutively with at least two streams, first and second repressurizing streams, with increasing oxygen content.

A method for producing oxygen by adsorbing a stream of atmospheric air, using a VPSA, including at least one adsorber, each adsorber undergoing a single pressure cycle including the following steps: a) producing a first stream of gas having an oxygen content T1 while loading the adsorber of the stream of atmospheric air upstream; b) producing a second stream of gas including an oxygen content T2<T1: c) producing a third stream of gas including an oxygen content T3<T2<T1 while simultaneously extracting a nitrogen-enriched residual stream; d) eluting the adsorber, from which the three streams of gas produced in steps a), b), and c) are taken with the second stream of gas produced in step b); e) repressurizing the adsorber consecutively with at least two streams, first and second repressurizing streams, with increasing oxygen content.

The present invention relates to a method for obtaining a hydrogen rich gas from an off gas. Further, the invention relates to a system for operating said method.

In various aspects, methods are provided for hydrogen production while reducing and/or mitigating emissions during various refinery processes that produce syngas, such as power generation. Syngas can be effectively separated to generate high purity carbon dioxide and hydrogen streams, while reducing and/or minimizing the energy required for the separation, and without needing to reduce the temperature of the flue gas. In various aspects, the operating conditions, such as high temperature, mixed metal oxide adsorbents, and cycle variations, for a pressure swing adsorption reactor can be selected to minimize energy penalties while still effectively capturing the CO.sub.2 present in syngas.

Disclosed are methods for removing acid gas from a feed stream of natural gas including acid gas, methane and ethane. The methods include alternating input of the feed stream between at least two beds of adsorbent particles comprising zeolite SSZ-13 such that the feed stream contacts one of the at least two beds at a given time in an adsorption step and a tail gas stream is simultaneously vented from another of the at least two beds in a desorption step. The contact occurs at a feed pressure of from about 50 to about 1000 psia for a sufficient period of time to preferentially adsorb acid gas from the feed stream. A product gas stream is produced containing no greater than about 2 mol % carbon dioxide and at least about 65 mol % of methane recovered from the feed stream and at least about 25 mol % of ethane recovered from the feed stream. The feed stream is input at a feed end of each bed. The product gas stream is removed from a product end of each bed. The tail gas stream is vented from the feed end of each bed. The methods require lower vacuum power consumption and allow improved hydrocarbon recoveries compared with known methods.

Disclosed are methods for removing acid gas from a feed stream of natural gas including acid gas, methane and ethane. The methods include alternating input of the feed stream between at least two beds of adsorbent particles comprising zeolite SSZ-13 such that the feed stream contacts one of the at least two beds at a given time in an adsorption step and a tail gas stream is simultaneously vented from another of the at least two beds in a desorption step. The contact occurs at a feed pressure of from about 50 to about 1000 psia for a sufficient period of time to preferentially adsorb acid gas from the feed stream. A product gas stream is produced containing no greater than about 2 mol % carbon dioxide and at least about 65 mol % of methane recovered from the feed stream and at least about 25 mol % of ethane recovered from the feed stream. The feed stream is input at a feed end of each bed. The product gas stream is removed from a product end of each bed. The tail gas stream is vented from the feed end of each bed. The methods require lower vacuum power consumption and allow improved hydrocarbon recoveries compared with known methods.

A pressure swing adsorption (PSA) system and a PSA process including a PSA cycle schedule are disclosed. The PSA cycle schedule includes an unlimited number of equalization steps, no idle steps, no dead time and a minimum number of three PSA adsorbent beds assisted with two or more equalization tanks. The PSA system, process and cycle schedule include the following sequence of cycle steps: a feed step, two or more down equalization steps either between beds or between a bed and a tank, an optional forced cocurrent depressurization step coupled with a forced intermediary light end pressurization step, a countercurrent depressurization step, a light reflux step, two or more up equalization steps between beds or between a bed and a tank, an optional forced intermediary light end pressurization step coupled with the forced cocurrent depressurization step, and a light product pressurization step.