Abstract: Pressure swing adsorption process and system for separating gas mixtures comprising at least one more strongly adsorbable component and at least one less strongly adsorbable component. The process includes storing gas enriched in one of the components in a first storage tank and a second storage tank which are arranged in series. Final product gas is provided from the second storage tank while gas for purge, rinse, and/or repressurization is provided from the first storage tank.

Abstract: An electrochemical device for separating oxygen from an oxygen-containing gas comprises a plurality of planar ion-conductive solid electrolyte plates and electrically-conductive gas-impermeable interconnects assembled in a multi-cell stack. Electrically-conductive anode and cathode material is applied to opposite sides of each electrolyte plate. A gas-tight anode seal is bonded between the anode side of each electrolyte plate and the anode side of the adjacent interconnect. A regulating electrode, applied to the anode side of each electrolyte plate between the anode seal and the edge of the anode, eliminates anode seal failure by maintaining the 24-hour anode seal power density below about 1.5 .mu.W/cm.sup.2. A gas-tight seal is applied between the cathode sides of each electrolyte plate and the adjacent interconnect such that the anode and cathode seals are radially offset on opposite sides of the plate.

Abstract: Synthesis gas is produced from a methane-containing reactant gas in a mixed conducting membrane reactor in which the reactor is operated to maintain the product gas outlet temperature above the reactant gas feed temperature wherein the total gas pressure on the oxidant side of the membrane is less than the total gas pressure on the reactant side of the membrane. Preferably, the reactant gas feed temperature is below a maximum threshold temperature of about 1400.degree. F. (760.degree. C.), and typically is between about 950.degree. F. (510.degree. C.) and about 1400.degree. F. (760.degree. C.). The maximum temperature on the reactant side of the membrane reactor is greater than about 1500.degree. F. (815.degree. C.).

Abstract: Hydrocarbon feedstocks are converted into synthesis gas in a two-stage process comprising an initial steam reforming step followed by final conversion to synthesis gas in a mixed conducting membrane reactor. The steam reforming step converts a portion of the methane into synthesis gas and converts essentially all of the hydrocarbons heavier than methane into methane, hydrogen, and carbon oxides. The steam reforming step produces an intermediate feed stream containing methane, hydrogen, carbon oxides, and steam which can be processed without operating problems in a mixed conducting membrane reactor. The steam reforming and mixed conducting membrane reactors can be heat-integrated for maximum operating efficiency and produce synthesis gas with compositions suitable for a variety of final products.

Abstract: A method and apparatus for introducing an oxidant mixed with a carrier gas into pre-heating zone of a continuous furnace for effectively removing lubricant from powder metal compacts prior to sintering at high temperatures. Mixing a controlled amount of a gaseous oxidizing agent such as moisture, carbon dioxide, air or mixtures thereof with a carrier gas and introducing the mixture into the preheating zone of a continuous furnace under controlled conditions accelerates removal of lubricant from powder metal compacts prior to sintering at high temperature by decomposing lubricant vapors into smaller and more volatile hydrocarbons, produces sintered components with close to soot- and residue-free surfaces and with the desired physical properties, prolongs the life of furnace components including muffles and belts, and reduces downtime, maintenance and operating costs.

Abstract: An electrochemical device for separating oxygen from an oxygen-containing gas comprises a plurality of planar ion-conductive solid electrolyte plates and electrically-conductive gas-impermeable interconnects assembled in a multi-cell stack. Electrically-conductive anode and cathode material is applied to opposite sides of each electrolyte plate. A gas-tight anode seal is bonded between the anode side of each electrolyte plate and the anode side of the adjacent interconnect. A biasing electrode, applied to the anode side of each electrolyte plate between the anode seal and the edge of the anode, eliminates anode seal failure by minimizing the electrical potential across the seal. The seal potential is maintained below about 40 mV and preferably below about 25 mV. A gas-tight seal is applied between the cathode sides of each electrolyte plate and the adjacent interconnect such that the anode and cathode seals are radially offset on opposite sides of the plate.

Abstract: An ozone containing gas stream is produced from oxygen by subjecting oxygen to an electric discharge and the ozone is then adsorbed on to a solid adsorbent, such as zeolite, the oxygen containing stream leaving the adsorbent is recycled to the ozonising process. Periodically, oxygen adsorbed on the adsorbent is desorbed by co-currently passing a purge gas over the adsorbent and the desorbed oxygen is also recycled to the ozoniser. Lastly ozone is desorbed from the adsorbent by a counter-current flow of purge gas and used in an ozone demanding process.

Abstract: A cryogenic air separation system which is subject to periods of significant changes in product demand is controlled during such periods to minimize the impact of transient operation on product purity. A double-column distillation system is utilized in which a nitrogen-rich liquid is withdrawn from the higher-pressure column and introduced into the lower-pressure column as reflux. An inventory of this liquid is maintained in a holdup tank for storage or withdrawal during periods of transient operation. In addition, nitrogen vapor product from the lower-pressure column is recycled to the higher-pressure column, and the nitrogen vapor recycle rate is controlled as a function of the liquid level in the holdup tank. The flow rate of nitrogen-rich liquid withdrawn from the higher-pressure column is controlled as a function of its composition.

Abstract: A carbonaceous adsorbent membrane is prepared by contacting a hydrophobic carbonaceous adsorbent membrane with an aqueous solution of one or more oxidizing acids and one or more metals selected from the group consisting of copper (+2), chromium (+3), and nickel (+2). The treated membrane is rinsed and dried to yield a hydrophilic carbonaceous adsorbent membrane which is useful for removing water from water-containing gas mixtures.

Abstract: A cryogenic air separation system which is subject to periods of significant changes in product demand is controlled during such periods to minimize the impact of transient operation on product purity. The feed air is introduced directly into the higher pressure column of a distillation system having at least two columns, and nitrogen-rich and oxygen-rich vapor products are withdrawn from the lower pressure column. The flow rate of the nitrogen-rich vapor product is controlled as a function of the feed air flow rate by a feed air flow controller which controls the suction pressure of the nitrogen product compressor. The set point of the flow controller is manipulated as a function of the composition of the oxygen-enriched vapor product. A nitrogen-rich liquid is withdrawn from the higher-pressure column and introduced into the lower-pressure column as reflux. An inventory of this liquid is maintained in a holdup tank for storage or withdrawal during periods of transient operation.

Abstract: A high purity methane product is recovered from a feed gas mixture containing methane and one or more hydrocarbons heavier than methane by cooling, condensing, and rectifying the feed in a dephlegmator. The high purity methane product, containing at least 98 mole % methane, can be liquefied and stored for use as a fuel for internal combustion engines. A hydrocarbon product containing components heavier than methane is also recovered.Methane recovery and C.sub.2.sup.+ hydrocarbon product purity can be improved by the use of a combined stripping heat exchanger and feed gas cooler. External refrigeration is utilized and can be supplemented in part by autorefrigeration provided by vaporizing dephlegmator liquid.

Abstract: Oxygen is produced by compressing air to provide a first and a second pressurized air stream, separating the first pressurized air stream into an oxygen-rich product stream and a nitrogen-rich byproduct stream, and combining the nitrogen-rich byproduct stream with the second pressurized air stream. The resulting combined stream is heated by indirect heat exchange with a hot process stream and is work expanded in a gas turbine expander. At least a portion of the expander shaft work is utilized for the air compression step. Fuel is combusted with the expander discharge stream to provide the hot process stream for heating the combined stream prior to expansion. The use of this integrated indirectly-fired gas turbine to provide pressurized feed air for the air separation system improves the availability and reliability of the integrated system compared with conventional directly-fired gas turbine systems.

Abstract: A double column cryogenic air separation system is operated to increase boilup in the lower pressure column by vaporizing at an intermediate pressure a liquid stream containing at least 20 mole % oxygen, work expanding the stream, and introducing the resulting expanded stream into the lower pressure column. Operation in this mode increases oxygen recovery at a given rate of compressed and purified air feed or reduces the amount air feed required to produce a given rate of oxygen product. Argon recovery can be integrated efficiently with the intermediate pressure vaporization and work expansion steps.

Abstract: Porous carbonaceous adsorptive membranes are protected or passivated from surface degradation in moist air by oxidizing the surface at relatively mild conditions after initial preparation of the membrane by pyrolysis. Carbon dioxide is a preferred passivating gas. Contact of passivated membranes with moist air at ambient conditions unexpectedly improves membrane effectiveness in separating gas mixtures containing hydrogen and light hydrocarbons.

Abstract: An integrated gasification combined cycle (IGCC) power generation system is operated at off-design conditions by introducing a supplemental fuel into the combustion turbine combustor to compensate for deviations from system design conditions. Such deviations include changes in ambient temperature and changes in the amount of extracted air required for the air separation system. The invention allows operation of the combustion turbine at or close to its maximum design power output and other components in the IGCC system at or close to their respective design points.

Abstract: Fine powders of iron with less than 5% by weight graphite, copper, and an organic binder can be formed into shapes having a green density of up to about 7.4 g/cc and sintered in a hydrogen containing atmosphere to yield parts having minimum variations in physical properties. Incorporation of small quantities of copper, e.g. 1% or less by weight, negates variations in physical properties of sintered parts that were subjected to variations in the hydrogen content of the sintering atmosphere.

Abstract: A single-bed PSA system comprising a blower, an adsorber vessel, and a gas product storage tank separates a gas mixture using a three-step cycle comprising adsorption, evacuation, and pressurization. Pressurization is accomplished by introducing gas from the gas product storage tank into both the feed end and the product end of the adsorber vessel. Preferably a portion of the pressurization gas is introduced into the adsorber vessel by the blower, which also is used for providing feed to the adsorber and for withdrawing gas from the adsorber during the evacuation step.

Abstract: An electrochemical device for separating oxygen from an oxygen-containing gas comprises a plurality of planar ion-conductive solid electrolyte plates and electrically-conductive gas-impermeable interconnects assembled in a multi-cell stack. Electrically-conductive anode and cathode material is applied to opposite sides of each electrolyte plate. A gas-tight anode seal is bonded between the anode side of each electrolyte plate and the anode side of the adjacent interconnect. A biasing electrode, applied to the anode side of each electrolyte plate between the anode seal and the edge of the anode, eliminates anode seal failure by minimizing the electrical potential across the seal. The seal potential is maintained below about 40 mV and preferably below about 25 mV. A gas-tight seal is applied between the cathode sides of each electrolyte plate and the adjacent interconnect such that the anode and cathode seals are radially offset on opposite sides of the plate.

Abstract: A method for improving the efficiency of a gasification combined cycle system for the coproduction of electric power and one or more chemical or liquid fuel products from a synthesis gas feed containing hydrogen and carbon monoxide. Waste heat is recovered from the chemical reaction system in the form of heated water which is used to heat and humidify one or more gas streams introduced into the combustor of the combined cycle system gas turbine. Waste refrigeration recovered from the synthesis gas purification system optionally is used to cool the air inlet to the gas turbine compressor.

Abstract: Ozone is recovered from an ozone-oxygen mixture by adsorption using an adsorbent which comprises a zeolite selected from the group consisting of L type zeolite, Y type zeolite, ZSM-5, and mordenite in which at least 90% of the exchangeable cation content is in the ammonium form and the molar ratio of potassium to aluminum is less than about 0.25. Alternatively, a proton-exchanged L type zeolite can be used in which at least 90% of the exchangeable cation content is in the proton form and the molar ratio of potassium to aluminum is less than about 0.25.