Abstract: Process and apparatuses for purifying a feed stream containing CO2 and predominantly hydrogen are provided. In an embodiment, the process includes passing the feed stream through a multilayer adsorbent bed comprising a first adsorbent section, a second adsorbent section downstream from the first adsorbent section and a third adsorbent section downstream from the second adsorbent section. The first adsorbent section comprises an activated carbon layer, the second adsorbent section comprises a layer of molecular sieve of the faujasite structure type with a Si/Al atomic ratio of from 1.5 to 8.0 and the third adsorbent section comprises a layer of molecular sieve of the faujasite structure type with a Si/Al atomic ratio of from 1.0 to 1.5. At least one of N2, CO2, CH4 and CO is adsorbed from the feed stream and a purified hydrogen product is recovered from the multilayer adsorbent bed.

Abstract: Process and apparatuses for purifying a feed stream containing CO2 and predominantly hydrogen are provided. In an embodiment, the process includes passing the feed stream through a multilayer adsorbent bed comprising a first adsorbent section, a second adsorbent section downstream from the first adsorbent section and a third adsorbent section downstream from the second adsorbent section. The first adsorbent section comprises an activated carbon layer, the second adsorbent section comprises a layer of molecular sieve of the faujasite structure type with a Si/Al atomic ratio of from 1.5 to 8.0 and the third adsorbent section comprises a layer of molecular sieve of the faujasite structure type with a Si/Al atomic ratio of from 1.0 to 1.5. At least one of N2, CO2, CH4 and CO is adsorbed from the feed stream and a purified hydrogen product is recovered from the multilayer adsorbent bed.

Abstract: The invention provides for sending a natural gas stream through a pressure swing adsorption unit to send a gas stream comprising mainly nitrogen, methane and hydrogen to a fuel gas stream and a gas stream comprising a significant majority of C2+ hydrocarbons from the natural gas stream to a tail gas stream to then go to a stream cracker.

Abstract: Methods of preparing an impurity-depleted hydrogen stream, methods of analyzing content of an impurity-depleted hydrogen stream from a pressure swing adsorption process, and pressure swing adsorption apparatuses are provided herein. In an embodiment, a method of analyzing content of an impurity-depleted hydrogen stream from a pressure swing adsorption process includes providing a hydrogen-containing feed stream to a pressure swing adsorption zone. The hydrogen-containing feed stream further includes an impurity content including methane and carbon monoxide. Methane and carbon monoxide are adsorbed from the hydrogen-containing feed stream in the pressure swing adsorption zone. The impurity-depleted hydrogen stream is withdrawn from the pressure swing adsorption zone, with the impurity-depleted hydrogen stream having a residual methane content and a residual carbon monoxide content. The residual methane content of the impurity-depleted hydrogen stream is sensed.

Abstract: Methods of preparing an impurity-depleted hydrogen stream, methods of analyzing content of an impurity-depleted hydrogen stream from a pressure swing adsorption process, and pressure swing adsorption apparatuses are provided herein. In an embodiment, a method of analyzing content of an impurity-depleted hydrogen stream from a pressure swing adsorption process includes providing a hydrogen-containing feed stream to a pressure swing adsorption zone. The hydrogen-containing feed stream further includes an impurity content including methane and carbon monoxide. Methane and carbon monoxide are adsorbed from the hydrogen-containing feed stream in the pressure swing adsorption zone. The impurity-depleted hydrogen stream is withdrawn from the pressure swing adsorption zone, with the impurity-depleted hydrogen stream having a residual methane content and a residual carbon monoxide content. The residual methane content of the impurity-depleted hydrogen stream is sensed.

Abstract: Adsorption vessels and systems utilizing adsorption vessels are provided herein. In one embodiment, an adsorption vessel for receiving a fluid mixture and for separating a component from therein includes a vessel wall extending from a bottom end to a top end and defining a vessel chamber. A bottom inlet is formed in the bottom end of the adsorption vessel for introducing the fluid mixture to the vessel chamber. Further, a support plate is positioned in the vessel chamber above the bottom end, and defines a bottom void volume between the support plate and the bottom end. A filler material having a total porosity of less than about 25% is positioned in the bottom void volume and defines a channel for flow of the fluid mixture from the bottom inlet to the support plate.

Abstract: The invention uses a calcium exchanged zeolite molecular sieve adsorbent in a pressure swing adsorption process to purify hydrogen from refinery off-gas streams. The use of this adsorbent provides for an improvement in removal of methane and allows for faster cycle times and the processing of a higher volume of hydrogen for a given size adsorption bed.

Abstract: A process for the purification of hydrogen based gas mixtures utilizing zeolite X wherein the particle size distribution of the zeolite X powder has a coefficient of variation from about 15% to about 30%.

Abstract: The present invention relates to a pressure swing adsorption process for direct reduction of iron wherein a portion of spent reducing gas withdrawn from the direct reduction reactor is subjected to a PSA process for the removal of carbon dioxide from the spent reducing gas. An improved CO2-rejection method using an external natural gas purge stream after depressurization and before the product purge step is described. The PSA process comprises an external purge step with a non-absorbable gas, which surprisingly reduces the adsorbent regeneration requirements to maintain the selective adsorption of carbon dioxide from the spent reducing gas. The external natural gas purge results in a cleaner bed before the start of each adsorption cycle. Consequently, significantly more CO2 can be rejected and/or higher hydrogen and CO recoveries can be attained. The external purge stream is fully integrated into the DDRI production scheme.

Abstract: The present invention relates to a pressure swing adsorption process for direct reduction of iron wherein a portion of spent reducing gas withdrawn from the direct reduction reactor is subjected to a PSA process for the removal of carbon dioxide from the spent reducing gas. An improved CO2-rejection method using an external natural gas purge stream after depressurization and before the product purge step is described. The PSA process comprises an external purge step with a non-adsorbable gas, which surprisingly reduces the adsorbent regeneration requirements to maintain the selective adsorption of carbon dioxide from the spent reducing gas. The external natural gas purge results in a cleaner bed before the start of each adsorption cycle. Consequently, significantly more CO2 can be rejected and/or higher hydrogen and CO recoveries can be attained. The external purge stream is fully integrated into the DRI production scheme.

Abstract: A feedstream comprising nitrous oxide is purified by a pressure swing adsorption process employing a copurge with an oxygen-lean stream to produce a high purity nitrous oxide stream. The high purity nitrous oxide stream can be incorporated in a complex for the production of adipic acid to recover nitrous oxide from a dilute waste stream and pass the recovered nitrous oxide to a process for the production of phenol from an aromatic hydrocarbon. Unreacted nitrous oxide from the phenol production step acid can be recovered in a second, or vent PSA step, and combined with the recovery of byproduct nitrous oxide waste streams from the production of adipic for the overall recovery of nitrous oxide, thereby significantly reducing nitrous oxide emissions from the production of adipic acid.

Abstract: A process claimed for the removal of VOCs from fluid streams. The process comprises a vacuum swing adsorption zone containing at least 2 adsorption beds wherein the adsorbent beds are cocurrently purged with a diluent stream comprising an inert gas prior to a countercurrent evacuation step. In addition, the adsorbent beds may contain a first adsorption layer comprising an adsorbent selective for the adsorption of the inert gas, whereby the inert gas is retained within the VSA system to prevent the creation of an explosive mixture upon the condensation of the desorbed VOCs.

Abstract: A process claimed for the removal of VOCs from fluid streams. The process comprises a vacuum swing adsorption zone containing at least 2 adsorption beds wherein the adsorbent beds are cocurrently purged with a diluent stream comprising an inert gas prior to a countercurrent evacuation step. In addition, the adsorbent beds may contain a first adsorption layer comprising an adsorbent selective for the adsorption of the inert gas, whereby the inert gas is retained within the VSA system to prevent the creation of an explosive mixture upon the recovery of the desorbed VOCs.

Abstract: A process claimed for the removal of VOCs from fluid streams. The process comprises a vacuum swing adsorption zone containing at least 2 adsorption beds wherein the adsorbent beds are cocurrently purged with at diluent stream comprising an inert gas prior to a countercurrent evacuation step. In addition, the adsorbent beds may contain a first adsorption layer comprising an adsorbent selective for the adsorption of the inert gas, whereby the inert gas is retained within the VSA system to prevent the creation of an explosive mixture upon the condensation of the desorbed VOCs.

Abstract: An integrated process for treating a vent gas stream containing halogenated organic compounds to produce a clean vent gas with vacuum swing adsorption of the halogenated organic compounds and the recycle of a gaseous stream from the halogenated organic compound recovery section. A liquid sponge oil containing halogenated organic compounds is contacted and admixed with the evacuated effluent from the adsorption zone to prevent the accumulation of normally gaseous hydrocarbonaceous compounds.

Abstract: The number of beds on the adsorption step of a pressure swing adsorption cycle is varied cyclically throughout the cycle. As a result, the final bed repressurization step is separated from the partial repressurization-pressure equalization step, thereby enhancing product recovery, without discontinuity in the flow of product effluent from the adsorption system or the use of an external repressurization storage tank.

Abstract: Void space gas is released from an adsorbent bed at a higher adsorption pressure by cocurrent depressurization of the bed. The released gas is passed to another bed of a pressure swing adsorption system to equalize the pressure therebetween, the other bed being initially at a lower pressure. A portion of the product effluent withdrawn from yet another bed of the system is not passed to the bed undergoing repressurization, as in conventional practice, but is passed to an external repressurization storage tank during said pressure equalization step. Upon completion of this step, the product effluent is withdrawn from the repressurization tank and passed to said bed undergoing repressurization.