A method and device for stepwise pressure-equalized pressure swing adsorption (PSA) gas separation by changing paths. A pressure equalization process is alternately performed between two groups of adsorbers, where one group performing an equalization depressurization (ED) process is an ED adsorber, while the other group performing an equalization repressurization (ER) process simultaneously is an ER adsorber. Each of the adsorbers has a feed port, an intermediate port, and a discharge port. Gas of the ED adsorber flows out through the discharge port and the intermediate port in the ED process. In the ER process, gas flowing out from the discharge port flows through the discharge port and intermediate port, and gas flowing out from the intermediate port flows through the intermediate port and the feed port, or flows in through one of the intermediate port and feed port.

We provide a method for removing contaminants from a gas, comprising: alternating input of the gas between two or more beds of adsorbent particles that comprise zeolite SSZ-36, zeolite SSZ-39, or zeolite SSZ-45; wherein the gas contacts one of the beds during an adsorption and a tail gas is simultaneously vented from another of the beds by desorption; wherein a contacting pressure is from about 345 kPa to about 6895 kPa and produces a product gas containing no greater than about 2 mol % carbon dioxide, at least about 10 wppm water, at least about 65 mol % of methane recovered from the feed gas, and at least about 25 mol % of ethane recovered from the feed gas; and wherein the tail gas is vented from the feed end of the beds. We also provide a method for removing a contaminant from a gas, wherein the gas contains hydrogen sulfide.

Provided herein is a method for improving a gas recovery rate during generation of a high-purity gas. The method includes providing three or more adsorption towers filled with an adsorbent that adsorbs an adsorption target gas. Performing a pressure lowering equalization process in a first adsorption tower in which an adsorption process has been finished, and in a source gas supply state in which a source gas is supplied to at least a second adsorption tower in which a pressure increasing equalization process has been finished and the adsorption process is to be subsequently performed; and transferring a non-adsorbed gas from an upper portion of the first adsorption tower to the upper portion of the second adsorption tower, thereby performing an adsorption and pressure lowering equalization process in the first adsorption tower and an adsorption and pressure increasing equalization process in the second adsorption tower.

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.

Adsorbent material for use in pressure swing adsorption (PSA) related processing can provide improved purification processing with reduced temperature differentials between adsorption and desorption processing of the bed of adsorbent material. Embodiments can be configured so that adsorbent material has occluded micropores or macropores. The occlusion of the micropores or macropores can be up to 42% of the micropores the adsorbent material in some embodiments. At least one metal acetate can be utilized for the occlusion of the micropores or macropores. Utilization of the adsorbent material having occluded micropores or macropores was surprisingly found to increase the yield for purification of a product gas in spite of the occlusion of the micropores or macropores.