1899results about "Hydrogen separation using solid contact" patented technology

The present invention provides a method and system for efficiently producing hydrogen that can be supplied to a fuel cell. The method and system of the present invention produces hydrogen in a reforming reactor using a hydrocarbon stream and water vapor stream as reactants. The hydrogen produced is purified in a hydrogen separating membrane to form a retentate stream and purified hydrogen stream. The purified hydrogen can then be fed to a fuel cell where electrical energy is produced and a fuel cell exhaust stream containing water vapor and oxygen depleted air is emitted. In one embodiment of the present invention, a means and method is provided for recycling a portion of the retentate stream to the reforming reactor for increased hydrogen yields. In another embodiment, a combustor is provided for combusting a second portion of the retentate stream to provide heat to the reforming reaction or other reactants. In a preferred embodiment, the combustion is carried out in the presence of at least a portion of the oxygen depleted air stream from the fuel cell. Thus, the system and method of the present invention advantageously uses products generated from the system to enhance the overall efficiency of the system.

Pressure swing adsorption (PSA) separation of a gas mixture is performed in an apparatus with a plurality of adsorbent beds. The invention provides rotary multiport distributor valves to control the timing sequence of the PSA cycle steps between the beds, with flow controls cooperating with the rotary distributor valves to control the volume rates of gas flows to and from the adsorbent beds in blowdown, purge, equalization and repressurization steps.

Hydrogen is produced from solid or liquid carbon-containing fuels in a two-step process. The fuel is gasified with hydrogen in a hydrogenation reaction to produce a methane-rich gaseous reaction product, which is then reacted with water and calcium oxide in a hydrogen production and carbonation reaction to produce hydrogen and calcium carbonate. The calcium carbonate may be continuously removed from the hydrogen production and carbonation reaction zone and calcined to regenerate calcium oxide, which may be reintroduced into the hydrogen production and carbonation reaction zone. Hydrogen produced in the hydrogen production and carbonation reaction is more than sufficient both to provide the energy necessary for the calcination reaction and also to sustain the hydrogenation of the coal in the gasification reaction. The excess hydrogen is available for energy production or other purposes. Substantially all of the carbon introduced as fuel ultimately emerges from the invention process in a stream of substantially pure carbon dioxide. The water necessary for the hydrogen production and carbonation reaction may be introduced into both the gasification and hydrogen production and carbonation reactions, and allocated so as transfer the exothermic heat of reaction of the gasification reaction to the endothermic hydrogen production and carbonation reaction.

A system and method for co-production of hydrogen and electrical energy. The system comprises a fuel cell assembly comprising a plurality of fuel cells. The fuel cells further comprise a cathode inlet for receiving a compressed oxidant, an anode inlet for receiving a fuel feed stream, an anode outlet in fluid communication with an anode exhaust stream and a cathode outlet in fluid communication with a cathode exhaust stream. At least a portion of the fuel feed stream reacts with the oxidant to produce electrical power. The anode exhaust stream comprises hydrogen. The co-production system further comprises a separation unit in fluid communication with the fuel cell assembly. The separation unit is configured to receive the anode exhaust stream from the fuel cell assembly to separate hydrogen from the anode exhaust stream.

An electrical current generating system is disclosed that includes a fuel cell operating at a temperature of at least about 250° C. (for example, a molten carbonate fuel cell or a solid oxide fuel cell), a hydrogen gas separation system or oxygen gas delivery system that includes a compressor or pump, and a drive system for the compressor or pump that includes means for recovering energy from at least one of the hydrogen gas separation system, oxygen gas delivery system, or heat of the fuel cell. The drive system could be a gas turbine system. The hydrogen gas separation system or the oxygen gas delivery system may include a pressure swing adsorption module.

A process for the separation/recovery of gases is described where the desired component to be separated from the gaseous mixture is present in low/very low molar amount and/or low/moderate pressure, the process comprising contacting the gaseous mixture with a separation membrane unit containing high permeability/medium selectivity membranes which separate the feed stream into a permeate stream, enriched in the desired component and at a lower pressure and a retentate stream lean in the desired component and at a higher pressure. The retentate stream is made to convey its pressure to the permeate stream which then is directed to an adsorption PSA unit for further purification of the permeate stream so that the effluent stream from the PSA unit which contains the purified component has a purity of up to 99.90%. The process is useful for separating hydrogen from refinery off gases such as FCC gases and can also be applied to other gases such as helium and any other valuable gases present in gaseous streams in low to very low molar contents and low to moderate pressures.

A steam methane reforming method in which a feed stream is treated in a reactor containing a catalyst that is capable of promoting both hydrogenation and partial oxidation reactions. The reactor is either operated in a catalytic hydrogenation mode to convert olefins into saturated hydrocarbons and/or to chemically reduce sulfur species to hydrogen sulfide or a catalytic oxidative mode utilizing oxygen and steam to prereform the feed and thus, increase the hydrogen content of a synthesis gas produced by a steam methane reformer. The method is applicable to the treatment of feed streams containing at least 15% by volume of hydrocarbons with two or more carbon atoms and/or 3% by volume of olefins, such as a refinery off-gas. In such case, the catalytic oxidative mode is conducted with a steam to carbon ratio of less than 0.5, an oxygen to carbon ratio of less than 0.25 and a reaction temperature of between about 500° C. and about 860° C. to limit the feed to the steam methane reformer to volumetric dry concentrations of less than about 0.5% for the olefins and less than about 10% for alkanes with two or more carbon atoms.

A process and system for providing a hydrogen-containing gas stream to a fuel cell anode that includes providing a hydrogen-containing gas stream that includes carbon monoxide, introducing the hydrogen-containing gas stream into a pressure swing adsorption module that includes at least one carbon monoxide-selective adsorbent to produce a purified hydrogen-containing gas stream, and introducing the purified hydrogen-containing gas stream to the fuel cell anode. The pressure swing adsorption module can also include a second adsorbent and/or catalyst. Also disclosed is a fuel cell system coupled to an internal combustion engine and a fuel cell system that utilizes fuel cell waste heat for vaporizing a hydrocarbon/water mixture.

Hydrogen (H₂) gas and crude carbon dioxide (CO₂) gas are separated from a gaseous mixture thereof. Combustible gas(es) in the crude CO₂ gas are combusted to produce heat, at least a portion of which is recovered by indirect heat exchange with at least a portion of the separated H₂ gas or a gas derived therefrom. The invention may be integrated with coal-fired power stations to reduce or eliminate emission of harmful components into the atmosphere.

The present invention relates to processes for preparing gaseous products, and in particular methane, via the hydromethanation of carbonaceous feedstocks in the presence of steam, carbon monoxide, hydrogen and a hydromethanation catalyst.

A method of producing a carbon dioxide product stream from a synthesis gas stream formed within a hydrogen plant having a synthesis gas reactor, a water-gas shift reactor, located downstream of the synthesis gas reactor to form the synthesis gas stream and a hydrogen pressure swing adsorption unit to produce a hydrogen product recovered from the synthesis gas stream. In accordance with the method the carbon dioxide from the synthesis gas stream by separating the carbon dioxide from the synthesis gas stream in a vacuum pressure swing adsorption system, thereby to produce a hydrogen-rich synthesis gas stream and a crude carbon dioxide stream and then purifying the crude carbon dioxide stream by a sub-ambient temperature distillation process thereby to produce the carbon dioxide product. A hydrogen synthesis gas feed stream to the hydrogen pressure swing adsorption unit is formed at least in part from the hydrogen rich stream.

The present invention provides compact adsorption systems that are capable of rapid temperature swings and rapid cycling. Novel methods of thermal swing adsorption and thermally-enhanced pressure swing adsorption are also described. In some aspects of the invention, a gas is passed through the adsorbent thus allowing heat exchangers to be very close to all portions of the adsorbent and utilize less space. In another aspect, the adsorption media is selectively heated, thus reducing energy costs. Methods and systems for gas adsorption/desorption having improved energy efficiency with capability of short cycle times are also described. Advantages of the invention include the ability to use (typically) 30-100 times less adsorbent compared to conventional systems.

A multi-channel modular device (10) processes between two fluid streams of different compositions. The device (10) includes a porous body (150) having a first plurality of feed-flow pathways (110) disposed in the body (150) for transporting a first stream (180). A pathway wall (114) surrounds each of the first plurality of feed-flow pathways (110) for processing the first stream (180) into a first composition (1852) and a second composition (1802). At least one feed-flow inlet (1101) is disposed in the body (150) for introducing the first stream (180) into the first plurality of feed-flow pathways (110). At least one feed-flow outlet (1102) is disposed in the body (150) for discharging the remaining first stream containing the second composition (1802). At least one second pathway (210) is disposed in the body (150) for transporting a second stream (280) having a second inlet (2101) and a second outlet (2102). A networked plurality of fluid conduits (152) formed in the porous body (150) provides the flow-conduit for the second stream (280) to sweep the first composition (1852) from each of the first plurality of the feed-flow pathways (110) to the second outlet (2102). A vessel (300) ports the inlets (1101 and 2101) and outlets (1102 and 2102) to provide a second stream flow access and for spacing the body within and away from the inner surfaces of the vessel (300) to provide a gap (310) for access. A partition (350) is disposed in the gap between the body and the vessel for diverting the flow within the gap (310).

A process for producing a high temperature CO_x-lean product gas from a high temperature CO_x-containing feed gas, includes: providing a sorption enhanced reactor containing a first adsorbent, a shift catalyst and a second adsorbent; feeding into the reactor a feed gas containing H₂, H₂O, CO and CO₂; contacting the feed gas with the first adsorbent to provide a CO₂ depleted feed gas; contacting the CO₂ depleted feed gas with the shift catalyst to form a product mixture comprising CO₂ and H₂; and contacting the product mixture with a mixture of second adsorbent and shift catalyst to produce the product gas, which contains at least 50 vol. % H₂, and less than 5 combined vol. % of CO₂ and CO. The adsorbent is a high temperature adsorbent for a Sorption Enhanced Reaction process, such as K₂CO₃ promoted hydrotalcites, modified double-layered hydroxides, spinels, modified spinels, and magnesium oxides.

Materials that are useful for absorption enhanced reforming (AER) of a fuel, including absorbent materials and catalyst materials. The materials can be fabricated by spray processing. The use of the materials in AER can produce a H₂ product gas having a high H₂ content and a low level of carbon oxides.

Solid absorbent materials that are useful for absorption of chemical species from a fluid, such as a gas stream or a liquid stream. The absorbent materials are formed by spray processing and posses a well-defined chemical composition and microstructure. The absorbent materials can have a high absorption capacity for a chemical species such as H₂S, CO₂, NO, and H₂ and have a high recylability, such that the chemical species can be absorbed and desorbed over a large number of cycles.