US4324564A — Adsorption beds and method of operation thereof

Claim 1

Independent Claim 294 words

A method of operating an adsorption bed having an adsorbent material disposed within a housing defining a feed entrance, a fluid flow path, and a product exit, said adsorbent material being of the type used to reduce the concentration of an adsorbate carried by a fluid feed, said method including cycling the bed through an adsorption stage wherein the fluid feed is passed through the bed and a fluid product of reduced adsorbent concentration is collected at the product exit, and a thermal regeneration stage wherein a hot regenerant fluid and a cooling fluid are serially passed through the bed co-currently to one another to produce a fluid waste having an adsorbate concentration substantially greater than said fluid feed at a waste exit wherein, during said regeneration stage, there is created in the bed an RW front having a first velocity, said RW front being bounded on its downstream side by bed conditions characteristic of equilibrium between the adsorbent material and the fluid waste and on its upstream side by bed conditions characteristic of equilibrium between the adsorbent material and the hot regenerant fluid, and upstream of said RW front, there is created in the bed by the introduction of said cooling fluid having a lower temperature than said regenerant fluid, a thermal front having a velocity greater than said first velocity, said thermal front being bounded on its downstream side by high temperature conditions and on its upstream side by low temperature conditions, wherein the improvement comprises: introducing said cooling fluid into the bed before the midpoint of the RW front exits the bed to produce, during a portion of the cooling fluid flow, fluid waste at said waste exit having an adsorbate concentration substantially greater than the adsorbate concentration of said feed.

Claim 2

Independent Claim 294 words

A method of operating an adsorption bed having an adsorbent material disposed within a housing defining a feed entrance, a fluid flow path, and a product exit, said adsorbent material being of the type used to reduce the concentration of an adsorbate carried by a fluid feed, said method including cycling the bed through an adsorption stage wherein the fluid feed is passed through the bed and a fluid product of reduced adsorbent concentration is collected at the product exit, and a thermal regeneration stage wherein a hot regenerant fluid and a cooling fluid are serially passed through the bed co-currently to one another to produce a fluid waste having an adsorbate concentration substantially greater than said fluid feed at a waste exit wherein, during said regeneration stage, there is created in the bed an RW front having a first velocity, said RW front being bounded on its downstream side by bed conditions characteristic of equilibrium between the adsorbent material and the fluid waste and on its upstream side by bed conditions characteristic of equilibrium between the adsorbent material and the hot regenerant fluid, and upstream of said RW front, there is created in the bed by the introduction of said cooling fluid having a lower temperature than said regenerant fluid, a thermal front having a velocity greater than said first velocity, said thermal front being bounded on its downstream side by high temperature conditions and on its upstream side by low temperature conditions, wherein the improvement comprises: introducing said cooling fluid into the bed before the midpoint of the RW front exits the bed to produce, during a portion of the cooling fluid flow, fluid waste at said waste exit having an adsorbate concentration substantially greater than the adsorbate concentration of said feed.

Claim 3

Dependent Claim 27 words

The method of claim 1 wherein the timing of said cooling fluid introduction results in the collision of said RW and thermal fronts adjacent said waste exit.

Claim 4

Dependent Claim 47 words

The method of claim 1 wherein the timing of said cooling fluid introduction is such that when the midpoint of said RW front is at the bed exit, said thermal front is within the bed in the one-third mass of said adsorbent material adjacent said waste exit.

Claim 5

Dependent Claim 80 words

The method of claim 1 or 2 wherein the adsorbate and adsorbent comprise a pair selected from the group consisting of H 2 O/silica gel, H 2 O/activated alumina, H 2 O/alumina gel, H 2 O/molecular sieve zeolite, CO 2 /activated carbon, CO 2 /molecular sieve zeolite, Hg/zeolite, Hg/activated carbon, NO x /zeolite, NO x /activated carbon, SO x /zeolite, XO x /activated carbon, H 2 S/zeolite, H 2 S/activated carbon, salt/thermally regenerable ion exchange resin, and organic species/activated carbon.

Claim 6

Dependent Claim 24 words

The method of claim 1 or 2 wherein the feed comprises a fluid selected from the group consisting of water, air, and natural gas.

Claim 7

Dependent Claim 39 words

The method of claim 1 or 2 wherein a feed stream is alternatively delivered to a subset of a plurality of beds, operated in the adsorption stage, while the other of said beds is operated in the regeneration stage.

Claim 8

Dependent Claim 24 words

The method of claim 1 or 2 wherein the introduction of said cooling fluid is triggered by a signal generated by a timing means.

Claim 9

Dependent Claim 37 words

The method of claim 1 or 2 wherein the introduction of said cooling fluid is triggered by a signal generated by means for sensing an intrinsic property characteristic of fluid at a selected point within the bed.

Claim 10

Dependent Claim 51 words

The method of claim 8 wherein said means for sensing comprise a temperature sensor disposed within the adsorbent within said bed, said signal being generated in response to a change in temperature within a portion of said bed and being indicative of the movement of a front past said temperature sensor.

Claim 11

Dependent Claim 25 words

The method of claim 1 or 2 wherein said bed defines an axial fluid flow path disposed between a feed entrance and said product exit.

Claim 12

Dependent Claim 25 words

The method of claim 1 or 2 wherein said bed defines a radial fluid flow path disposed between said feed entrance and said product exit.

Claim 13

Dependent Claim 20 words

The method of claim 1 or 2 wherein said bed is operated as a fluidized bed during said adsorption stage.

Claim 14

Dependent Claim 44 words

The method of claim 1 or 2 wherein said bed comprises a compartmentalized structure and a plurality of flowpaths and includes means to direct a selected fluid flow through a selected compartment of said structure whereby regeneration, cooling, and adsorption are conducted substantially simultaneously.

Claim 15

Dependent Claim 22 words

The method of claim 1 or 2 wherein said fluid feed is treated to reduce the concentration of a plurality of adsorbates.

Claim 16

Dependent Claim 16 words

The method of claim 1 or 2 wherein said bed comprises a plurality of adsorbent materials.

Claim 17

Dependent Claim 17 words

The method of claim 15 wherein said adsorbent materials are arranged in layers along said flow path.

Claim 18

Dependent Claim 43 words

The method of claim 1 or 2 wherein product is used as the fluids in said regeneration stage and wherein the sum of the mass of hot regenerant fluid and cooling fluid is less than about 60% of the mass of the feed.

Claim 19

Dependent Claim 36 words

The method of claim 1 or 2 wherein said hot regenerant comprises a fluid selected from the group consisting of heated product, heated feed, heated purge gas, and heated, recirculated waste fluid of depleted adsorbate content.

Claim 20

Dependent Claim 82 words

The method of claim 1 or 2 wherein said hot regenerant and said cooling fluid are substantially adsorbate-free and, on the introduction of said cooling fluid, there is created within the bed a PR front comprising said thermal front, said PR front being bound on its downstream side by bed conditions characteristic of equilibrium between the adsorbent material and the hot regenerant fluid and on its upstream side by bed conditions characteristic of quilibrium between the adsorbent material and the cooling fluid.

Claim 21

Dependent Claim 25 words

The method of claim 1 or 2 wherein at least one of said hot reagent fluid and said cooling fluid contains a substantial adsorbate concentration.

Claim 22

Dependent Claim 17 words

The method of claim 1 or 2 comprising the additional step of recovering adsorbate from said waste.

Claim 23

Independent Claim 205 words

A method of operating an adsorption bed having an adsorbent material disposed within a housing defining a feed entrance, a fluid flow path, and a product exit, said adsorbent material being of the type used to reduce the concentration of an adsorbate carried by a fluid feed, said method including cycling the bed through an adsorption stage wherein the fluid feed is passed through the bed and a fluid product of reduced adsorbate concentration is collected at the product exit, and a thermal regeneration stage wherein a hot regenerant fluid of temperature T R and a cooling fluid are serially passed through the bed co-currently to one another to produce a fluid waste having an adsorbate concentration substantially greater than said fluid feed at a waste exit, said fluid waste having a maximum adsorbate concentration, Y MAX , wherein the improvement comprises: switching the flow of fluid entering the bed during regeneration from hot regenerant fluid to cooling fluid after the adsorbate concentration in the fluid falls below about 0.5 Y MAX at a selected point within the bed whereby during a portion of the cooling fluid flow the adsorbate concentration of said fluid waste exiting the bed is substantially equal to Y MAX .

Claim 24

Independent Claim 205 words

A method of operating an adsorption bed having an adsorbent material disposed within a housing defining a feed entrance, a fluid flow path, and a product exit, said adsorbent material being of the type used to reduce the concentration of an adsorbate carried by a fluid feed, said method including cycling the bed through an adsorption stage wherein the fluid feed is passed through the bed and a fluid product of reduced adsorbate concentration is collected at the product exit, and a thermal regeneration stage wherein a hot regenerant fluid of temperature T R and a cooling fluid are serially passed through the bed co-currently to one another to produce a fluid waste having an adsorbate concentration substantially greater than said fluid feed at a waste exit, said fluid waste having a maximum adsorbate concentration, Y MAX , wherein the improvement comprises: switching the flow of fluid entering the bed during regeneration from hot regenerant fluid to cooling fluid after the adsorbate concentration in the fluid falls below about 0.5 Y MAX at a selected point within the bed whereby during a portion of the cooling fluid flow the adsorbate concentration of said fluid waste exiting the bed is substantially equal to Y MAX .

Claim 25

Dependent Claim 32 words

The method of claim 22 comprising the step of triggering said switching with a signal generated by means for sensing an intrinsic property related to adsorbate concentration in fluid within the bed.

Claim 26

Dependent Claim 35 words

The method of claim 22 wherein said selected point lies along said flow path at a location so that the regeneration stage is complete before fluid waste exiting said waste exit reaches T R .

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1985-04-12	1985-10-12	1986-04-13	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1989-04-12	1989-10-12	1990-04-13	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1993-04-12	1993-10-12	1994-04-13	$7700.00	Window Closed / Lapsed

Adsorption beds and method of operation thereof

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