Praxair Technology, Inc.

Union Carbide Industrial Gases Technology Corporation

Union Carbide Corporation

Frederick Wells Leavitt

Mark William Ackley

Frank Notaro

James Smolarek

Herbert Raymond Schaub

Jeffert John Nowobilski

Mohamed Safdar Allie Baksh

Joseph Timothy Mullhaupt

Dale A Lagree

Michael Scott Kane

Victor Emmanuel Bergsten

Gregory William Henzler

Guoming Zhong

Timothy Mark Aaron

Alan Barnard Stewart

John Harry Fassbaugh

Michael John Sinicropi

Lee J Toussaint

Kimberly A LaSala

Antonio Felippe Figueiredo

Allastair Neill

Atanas Serbezov

A gas separation process incorporating the invention combines use of an adsorbent having high intrinsic diffusivity with a low pressure ratio PSA cycle. Further enhancements to the process are derived from the use of fast cycles, shallow beds and small particles&mdash;especially in a radial bed configuration. The combination of low pressure ratio, high rate adsorbents and fast cycles has been found to result in an unexpected simultaneous reduction in bed size factor (BSF) and power consumption. These benefits have been achieved while minimizing a decline in product recovery through use of the high rate adsorbent. The net result is a significant reduction in product cost.

Pressure swing adsorption gas separation method, using adsorbents with high intrinsic diffusivity and low pressure ratios

An improved pressure swing adsorption process and system for producing a high recovery of a highly purified product gas, such as argon, from a feed gas stream containing the product gas and impurity gases employs first and second adsorption stages with beds for adsorbing impurity gases. The system and process provides for sequential steps of: feed pressurization; simultaneous feed pressurization and product pressurization; adsorption; adsorption and purge; adsorption in the absence of purge; pressure equalization between beds; evacuation and depressurization of adsorbent bed; evacuation with product purge; evacuation without purge; and pressure equalization between beds.

Pressure swing adsorption process for high recovery of high purity gas

The invention is based upon the recognition that intrinsic sorption rates of adsorbent materials have a significant impact upon process performance. In a preferred embodiment an adsorption process uses an adsorbent zone comprising an adsorbent selected from the group consisting of A-zeolite, Y-zeolite, NaX, mixed cation X-zeolite, LiX having a SiO /Al O silica/alumina ratio of less than 3.0, chabazite, mordenite, clinoptilolite, silica-alumina, alumina, silica, titanium silicates and mixtures thereof, wherein the adsorbent has a mass transfer coefficient for nitrogen of k &gE;12 s and an intrinsic diffusivity for N , when measured at 1.5 bar and 300K, of D &gE;3.5&times;10 m /s. Other embodiments include the development of process parameters around which such materials should be used and methods of making such materials.

Rate-enhanced gas separation

The present invention is a two stage PSA process for producing high purity oxygen from a feed air stream. Water, carbon dioxide and nitrogen are removed in a first stage. An oxygen selective adsorbent is used to adsorb oxygen in the second stage. High purity oxygen product is recovered during regeneration of the second stage. Importantly, the high purity of the oxygen product is achieved without inclusion of an oxygen rinse step in the process cycle. The high purity oxygen product is obtained by collecting the middle cut of the second stage effluent stream during regeneration.

Pressure swing adsorption method for production of an oxygen-enriched gas

A low pressure swing adsorption process and apparatus for the recovery of carbon dioxide from multi-component gas mixtures, utilizing the simultaneous purge and evacuation of opposite ends of the adsorber(s) to effect controlled depressurization in the adsorber bed(s) to maintain the constant purity of a carbon dioxide-enriched product stream recovered from the adsorber inlet(s).

Pressure swing adsorption process and apparatus

An improved process for production of mixed cation-exchanged adsorbents that involves a single pass ion exchange. The precursor (non-exchanged) zeolite is treated with a combined essentially stoichiometric and excess solution of desirable weakly held and strongly held cations so that the resultant zeolite has the required mixed cation composition, while consuming smaller amounts of weakly held cation. Ion exchange post-treatment includes an optional equilibration step to ensure a uniform adsorbent and an optional washing step.

Mixed cation adsorbent having substantially uniform cation distribution

The invention comprises a PSA apparatus for the separation of a heavy component from a light component in a feed stream. The apparatus includes an adsorbent bed comprising either a mixture of adsorbents or composite adsorbent particles wherein each particle comprises two or more adsorbents. At least one of the adsorbents is comparatively weak and the other is comparatively strong. Another embodiment of the invention is a PSA prepurifier having a bed of adsorbent material which comprises a mixture of, or composite adsorbent particles wherein each particle comprises at least two adsorbents, at least one of the adsorbents being comparatively strong and at least another of the adsorbents being comparatively weak.

PSA apparatus and process using adsorbent mixtures

A pressure swing adsorption air prepurifier is used to remove water, carbon dioxide and hydrocarbons from a feed gas stream, such as a feed air stream, passing to a cryogenic air separation plant. By the incorporation of a regenerative heat exchange as an integral part of the air prepurifier, the cooling effects of the desorption of water are stored and transferred so as to cool the incoming feed air stream passing to the adsorbent material within the air prepurifier. The productive capacity of the adsorbent material is enhanced thereby.

Pressure swing adsorption air prepurifier

Adsorbent production with single pass ion exchange

This invention relates to a VPSA method for the production of a product that is enriched with a more preferred gas from a mixture of the more preferred gas and a less preferred gas and, preferably to a VPSA method for the production of an oxygen-enriched product from air, using an oxygen-preferential adsorbent under equilibrium conditions. In a preferred embodiment the process uses a desorption purge at a nearly constant pressure that is selected to produce a steady stream of oxygen having a purity from 30% to 60% at a pressure in the range of 60 kPa to 20 kPa.

Vacuum/pressure swing adsorption (VPSA) for production of an oxygen

Ions (e.g. lithium) can be removed or recovered from brines containing those ions and optionally one or more other ions (e.g. other alkali metal ions) by the use of a temperature-swing, ion-exchange process and apparatus employing an ion-exchange material. The process and apparatus depends on a change in the selectivity coefficient of an ion exchange material for the ions desired to be recovered with a change in temperature, resulting in desirable ions being relatively selectively released at one temperature and undesirable ions being relatively selectively released at another temperature. The process of the invention can be used to effect the separation of any ion (or set of ions) from another ion or from a set of ions wherein the selectivity coefficient for one ion (or set of ions) has a substantial temperature dependence, compared to that for the other ion (or set of ions).

Thermally-driven ion-exchange process for lithium recovery

An adsorption process and system for the selective adsorption of a more readily adsorbable component, such as nitrogen, as from air or other feed gas mixture is carried out using a composite adsorbent bed containing different adsorbent materials positioned in separate zones in which the temperature conditions favor adsorption performance of the particular adsorbent material under applicable processing conditions in each zone. A method for the selection of the adsorbent materials is based on Adsorption Figure of Merit values.

Adsorption process and system using multilayer adsorbent beds

The invention comprises a PSA gas prepurifier for the removal of contaminants present in a feed gas stream. The prepurifier of the invention has a bed of adsorbent material which comprises at least two discrete layers of adsorbents, at least one of the adsorbents being comparatively strong and at least another of the adsorbents being comparatively weak.

PSA gas purifier and purification process

Multiple thermal pulses are employed to regenerate segments of an adsorber bed simultaneously in thermal swing adsorption processes. The invention is particularly applicable to air purification as it helps to reduce purge flow and improve regeneration efficiency.

Multi-thermal pulse PSA system

A vessel for use in a pressure swing adsorption gas separation process includes an enclosing wall which defines an enclosed space having a top region and a bottom region. An annular adsorbent bed is positioned within the enclosed space and has a porous outer wall, a porous inner wall and adsorbent material positioned between the walls. The porous outer wall is separated from the enclosing wall to create a gas feed channel therebetween, and the porous inner wall surrounds an inner tank whose wall surface is separated from the porous inner wall and creates a product flow channel therebetween. A gas feed/distribution baffle structure is positioned in the bottom region of the vessel and in fluid communication with the gas feed channel to provide a gas feed thereto. The gas feed enters the gas feed channel and the adsorbent bed via the porous outer wall and in a direction generally radially towards the inner porous wall and product flow channel. A product outlet is positioned in the bottom region and in fluid communication with the product flow channel, for collecting product gas passing thereinto via the porous inner wall from the adsorbent bed. A flexible membrane extends between the porous outer wall and the porous inner wall, at the upper extremities thereof, and is pressurized so as to bear upon the upper surface of the adsorbent material to prevent fluidization during gas flow.

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Amherst, NY, United States of America

Frederick Wells Leavitt