Systems, equipment and methods suitable for drying a gas, for example a compressed gas, that utilize a drying cycle during which the gas flows through one or more dryer tanks and a desiccant material therein adsorbs a liquid entrained in the compressed gas to produce a dried compressed gas. A regeneration cycle is employed during which a purge gas flows through a purge gas dryer tank. During one or more phases of the regeneration cycle, a desiccant material within the purge gas dryer tank is employed to adsorb water vapor entrained in the purge gas to produce a dried purge gas, which is then directed through the dryer tank as part of the regeneration cycle performed on the desiccant materials within the dryer tanks.

This invention concerns a method for recovering carbon monoxide and carbon dioxide from Fischer-Tropsch off-gas by feeding Fischer-Tropsch off-gas through a column comprising an adsorbent bed, and discharging effluent, optionally rinsing the column and the adsorbent bed by feeding carbon dioxide and discharging effluent until at least 60% of the carbon monoxide that was present in the bed is discharged, pressurizing the column and adsorbent bed with carbon dioxide, rinsing the column and the adsorbent bed by feeding carbon dioxide, until at least 60% of the methane and optionally an amount equal to at least 50% of the carbon dioxide present at the commencement of this rinsing step is discharged, rinsing the column and adsorbent bed by feeding a mixture of hydrogen and nitrogen, pressurizing the column and adsorbent bed by feeding a mixture of hydrogen and nitrogen. With this method a feed comprising at least 50 vol % carbon monoxide can be produced. Furthermore, methane and carbon dioxide at a high pressure can be recovered from the Fischer-Tropsch gas. This can be fed to a gasifier or a reformer. In a preferred embodiment a gas comprising at least 80 vol % hydrogen is produced as well.

Systems and methods are provided for combined cycle power generation while reducing or mitigating emissions during power generation. Recycled exhaust gas from a power generation combustion reaction can be separated using a staged complementary swing adsorption process so as to generate a high purity CO.sub.2 stream while reducing/minimizing the energy required for the separation and without having to reduce the temperature of the exhaust gas. This can allow for improved energy recovery while also generating high purity streams of carbon dioxide and nitrogen.

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.

Provided are apparatus and systems for performing a swing adsorption process. This swing adsorption process may involve passing streams through adsorbent bed units to treat the feed stream to remove certain contaminants from the stream. In the method and system, active valves may be used with passive valves to manage the flow of the streams through the adsorbent bed units.

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 method for separating off carbon dioxide from a gas mixture, in particular from breathing air, with a life-sustaining device, wherein in a first method step the gas mixture is fed to an adsorption and/or absorption unit under at least one first pressure, and in a second method step a gas mixture is conveyed out of the adsorption and/or absorption unit under at least one second pressure that is higher than the first pressure.

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.

Provided are apparatus and systems for performing a swing adsorption process. This swing adsorption process may involve passing streams through adsorbent bed units to remove contaminants, such as water, from the stream. As part of the process, the adsorbent bed unit is purged with a purge stream that is provided at a temperature less than 450 F. The de-contaminated stream may be used with a liquefied natural gas (LNG) plant or other subsequent process requiring a de-contaminated stream. The swing adsorption process may involve a combined TSA and PSA process, which is utilized to remove contaminants from the feed stream.

Provided are apparatus and systems for performing a swing adsorption process. This swing adsorption process may involve passing streams through adsorbent bed units to remove contaminants, such as water, from the stream. As part of the process, the adsorbent bed unit is purged with a purge stream that is provided from the overhead of the demethanizer. The configuration integrates a PPSA dehydration system with a cryogenic recovery system.