Air Products and Chemicals, Inc.

David M Nicholas

Joseph P Bushinsky

Thomas M Roden

Ravi Kumar

Jeffrey Alan Hopkins

Shoou-I Wang

Wilbur C Kratz

David Edward Guro

Shankar Nataraj

William P Hegarty

Stephen P DiMartino, Sr

Stephen P Goff

Ruth Ann Davis

Nitin Madhubhai Patel

Gerry N Gottier

Gary S Roth

Arthur Daniel Bixler

Richard Alan Wright

David J Krichten

Dale D Smith

According to the present invention, hydrogen/carbon monoxide synthesis gas (also called syngas) is produced by injection of a second reactant stream into a hydrocarbon reformer at a location between the entry and discharge ends of the reformer. The second reactant stream can contain: carbon dioxide; a mixture of carbon dioxide and hydrocarbon; a mixture of hydrocarbon and steam, a mixture of carbon dioxide and steam; or a mixture of carbon dioxide with hydrocarbon and steam. All or part of the mixtures containing hydrocarbon and steam can be prereformed hydrocarbon in steam.

Reforming with intermediate reactant injection

Nitrogen is economically recovered from the flue gas evolved in a hydrocarbon steam reforming furnace by hydrogenation of free oxygen therein and removal of carbon dioxide and other minor impurities from the flue gas by pressure swing adsorption with recovery of high purity nitrogen is unsorbed effluent. The process is utilized to highest advantage in the production of ammonia syngas wherein natural gas or other hydrocarbon feed is subjected to steam reforming in a fuel-fired furnace. The nitrogen obtained by purification of the flue gas is combined with the purified hydrogen separated from the reformate providing the syngas for conversion to ammonia. In a preferred embodiment, the steam reforming is carried out in two stages, the first stage being performed in a conventional fuel-fired steam reforming furnace to which a major portion of the fresh hydrocarbon feed is charged. The hot effluent from this first reforming stage is employed as the heating medium to support reforming of the remaining minor portion of the fresh feed by heat exchange therewith.

Production of ammonia synthesis gas

The present invention is an integrated process for the adsorptive recovery of a high purity carbon monoxide product from a gas mixture containing hydrogen, carbon monoxide, carbon dioxide, methane, and nitrogen, with the potential additional recovery of a hydrogen-rich stream and the recycle of the resulting gas mixture to a reformation reaction to produce the gas mixture with a more favorable carbon monoxide and hydrogen product slate. Separate carbon dioxide recovery can be performed. Hydrogen recovery can be either by adsorptive or by membrane technology. The process achieves high recoveries at reduced capital cost and at reduced product cost.

Integrated processes for the production of carbon monoxide

A method is disclosed for producing ammonia synthesis gas by splitting a methane stream, combusting a portion of the methane with steam and oxygen-enriched air, converting a second portion of the methane with steam in a reformation heated by the combustion products of the first portion and combining the two portions for the water gas shift reaction followed by adsorptive separation of contained carbon dioxide.

Carbon black is produced from a pyrolyzed hydrocarbon wherein pyrolysis is effected by combusting a synthesis gas containing hydrogen and carbon monoxide. The synthesis gas is produced from reforming a hydrocarbon fuel, wherein the reformation is heated by combusting carbon black effluent tail gas or indirect heat exchange of the hot tail gas.

Integrated reformer process for the production of carbon black

Nitrogen is economically recovered from the flue gas evolved in a hydrocarbon steam reforming furnace by hydrogenation of free oxygen therein and removal of carbon dioxide and other minor impurities from the flue gas by pressure swing adsorption with recovery of high purity nitrogen as unsorbed effluent. The process is utilized to highest advantage in the production of ammonia syngas wherein natural gas or other hydrocarbon feed is subjected to steam reforming in a fuel-fired furnace. The nitrogen obtained by purification of the flue gas is combined with the purified hydrogen separated from the reformate providing the syngas for conversion to ammonia. In a preferred embodiment, the steam reforming is carried out in two stages, the first stage being performed in a conventional fuel-fired steam reforming furnace to which a major portion of the fresh hydrocarbon feed is charged. The hot effluent from this first reforming stage is employed as the heating medium to support reforming of the remaining minor portion of the fresh feed by heat exchange therewith.

Adsorptive process for recovering nitrogen from flue gas

Substantially pure hydrogen and high purity carbon monoxide are produced and recovered from a methane-rich gas composition, such as natural gas, by subjecting such composition to steam reforming in a first stage at relatively mild conditions, followed by secondary oxidative reforming of the thus obtained primary reformate effecting conversion of residual methane therein to carbon oxides. The secondary reformate, comprised chiefly of hydrogen, CO, and CO.sub.2, is subjected to a novel sequence of operations for separation of these individual components. CO.sub.2 is first removed by solvent absorption, followed by selective adsorption for separation of CO from the CO.sub.2 -freed gas mixture with attendant recovery of hydrogen product of 98.sup.+ % purity as an unsorbed effluent. Trace to small amounts of undesired carbon monoxide in the thus recovered hydrogen product can be converted by catalytic methanation.

Production of hydrogen and carbon monoxide

Crude ammonia synthesis gas is obtained by primary steam reforming of a hydrocarbon gas mixture rich in methane, such as natural gas, followed by secondary reforming of the primary reformate with added air and shift conversion of the contained CO to CO.sub.2. The shift conversion product is first freed of contained CO.sub.2 by selective absorption in a novel PSA unit having an integrated B section for removal of remaining impurities such as carbon monoxide and methane, thereby providing as product a gas stream comprised of hydrogen and nitrogen in approximate 3:1 molar ratio accompanied by a small amount or argon derived from the air stream used in the secondary reforming step. Alternative embodiments are disclosed for removal of CO from the gas stream, before its entry into the NH.sub.3 conversion operation; any residual CO that might have slipped thorugh the absorbent bed of the B section is converted to CH.sub.4.

Purification of ammonia syngas

Separation and individual recovery of high purity hydrogen and carbon monoxide from a mixed gas stream containing these compounds in association with carbon dioxide and one or more minor components such as particularly methane, is achieved by pressure swing adsorption to remove contained carbon dioxide from the charged gas, and further treatment of the CO.sub.2 -freed gas product by a sequence of steps utilizing (a) pressure swing adsorption and (b) selective permeation through a series of semi-permeable membranes, which steps (a) and (b) are carried out in either order of sequence.

Production and recovery of hydrogen and carbon monoxide

High purity methane is recovered from a fuel gas stream containing the same in admixture with mainly nitrogen and carbon dioxide, by first removing the carbon dioxide by selective adsorption in a PSA system and separating the remaining nitrogen from the methane by cryogenic distillation, the rejected nitrogen being employed for purging the CO.sub.2 -laden adsorbent beds of the PSA system. Cyclic regeneration of the sorbent-laden bed may entail nitrogen purge with or without including a carbon dioxide rinse, or the nitrogen purge of the sorbent-laden bed may be used in combination with pressure let-down by gas withdrawal into one or more companion beds.

Hydrocarbon recovery from fuel gas

Hydrogen and carbon monoxide are each separately recovered in high yield from a multicomponent gas stream containing these compounds together with carbon dioxide and a zero to minor amount of one or more gaseous components from the group consisting of nitrogen, methane, water vapor and C.sub.2 -C.sub.6 hydrocarbons, by a process wherein the multicomponent gas stream, such as that obtained by steam methane reforming, is initially treated in a pressure swing adsorption unit to remove water and CO.sub.2, and the obtained effluent freed of CO.sub.2 and water is then further subjected to (1) cryogenic fractionation to condense CO and to (2) hydrogen purification by selective adsorption (in either order) to recover high purity carbon monoxide and essentially pure hydrogen. The CO.sub.2 -laden adsorbent is regenerated by purging with a H.sub.2 O and CO.sub.2 -free waste gas stream from the hydrogen purification adsorbent bed or from the cryogenic fractionation or from both of these.

Gas separation process

The present invention involves a process for recovering hydrogen from a feed gas mixture comprising hydrogen and at least one other component. The feed gas mixture is initially separated in a membrane separation unit to produce a hydrogen-rich stream and a hydrogen-lean stream. The hydrogen-lean stream is subsequently treated in a cryogenic separation unit to remove a portion of the non-hydrogen components and produce a hydrogen-enriched stream. The hydrogen-enriched stream from the cryogenic separation unit is recycled and combined with the feed gas mixture to the membrane separation unit.

Hybrid membrane/cryogenic process for hydrogen purification

Wastewater is passed sequentially through an anaerobic treating zone and an oxic treating zone, followed by separation from the treated liquor of a dense sludge containing activated biomass, a least part of which is recycled to provide the activated biomass employed in treating the influent wastewater. Of the part of the sludge so recycled a minor portion is introduced into the anaerobic treating zone for admixture with the wastewater influent and the remaining major portion is introduced into the oxic treating zone, into which oxic zone oxygen-containing gas is admitted to effect oxygenation of the contents of that zone.

Nitrogen and phosphorus removal from wastewater

A process for promoting the reabsorption and retention by an activated biomass of phosphorous values previously contained by the biomass and released under anaerobic conditions, which process requires initially subjecting the biomass in admixture with a liquid medium to treatment under aerobic conditions employing a relatively high DO. When the pH of the mixture stops increasing, the aerobic treatment is continued but under a second, reduced DO level.

Process for reabsorption and retention of phosphorous by activated

A novel method is disclosed for treating a contaminated gas such as a contaminated natural gas or a synthesis product gas from the partial oxidation of petroleum or coal to concentrate and remove hydrogen sulfide at a reduced energy and capital requirement. Hydrogen sulfide in the contaminated stream is absorbed to form a hydrogen sulfide rich solvent which includes co-absorbed carbon dioxide, which is then removed to prevent dilution of the concentrated hydrogen sulfide formed when the solvent is regenerated. The solvent leaving the hydrogen sulfide absorber is heated before entering a high pressure stripper column wherein the co-absorbed carbon dioxide is stripped from the solvent, preferably by stripping with nitrogen or a portion of the product gas, and the carbon dioxide is recycled to the hydrogen sulfide absorber. The CO.sub.2 stripper is operated at a pressure not substantially below the pressure of the hydrogen sulfide absorber, eliminating the need for large compressors required in conventional methods to recycle the carbon dioxide.

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New Tripoli, PA, United States of America

David M Nicholas