Abstract: A method of storing and transporting acetylene comprises mixing acetylene gas and carbon dioxide gas and then reducing the temperature of the gas mixture thus obtained to obtain either a liquid-vapour or solid-vapour mixture and storing the liquid-vapour mixture or solid-vapour mixture in a pressure vessel.

Abstract: An apparatus for purifying feed air by adsorption of water vapor and carbon dioxide therefrom includes a purification vessel in which are defined vertically arrange chambers and another purification vessel in which are defined vertically arranged chambers. None of the chambers is in a series flow relationship with any of the others. Each chamber contains a bed of one or more adsorbents which is able to adsorb water vapor and carbon dioxide from the feed air and which forms a reversible part of a gas flow path extending between locations external of the vessels. Valves are associated with the vessel and are operable to permit during a first adsorption period of time simultaneous flows of air to to purified through at least two of the chambers and during a second regeneration period of time simultaneous reverse flows of regeneration gas through the same chambers.

Abstract: Food grade carbon dioxide is produced from oxyfuel fired glassmaking furnace waste gas by a series of steps including quenching the waste gas with aqueous quench liquid, dry-filtering sulfur salt from the gas, scrubbing the filtered gas with aqueous carbonate to convert the remaining sulfur dioxide to an aqueous sulfite suspension and using the suspension as part or all of the above-mentioned aqueous quench liquid, contacting the sulfur dioxide-free waste gas with ammonia in the presence of a catalyst that selectively converts nitrogen oxides to nitrogen, thereby removing substantially all nitrogen oxides from the waste gas, and distilling the resulting waste gas stream thereby producing high purity liquid carbon dioxide and producing an off-gas, which is recycled to the furnace as fuel.

Abstract: A hydrocarbon stream is cracked to produce a hot gaseous stream which is compressed and cooled to condense almost all of the hydrocarbons contained in the stream. A noncondensed stream remaining after the condensation step, comprised predominantly of hydrogen and C.sub.1 to C.sub.3 hydrocarbons, is subjected to pressure swing adsorption or temperature swing adsorption at an adsorption temperature of about 0.degree. to about 250.degree. C. in a bed of adsorbent which selectively adsorbs ethylene and propylene, thereby adsorbing substantially all of the ethylene and propylene from the gas stream. The ethylene and/or propylene is recovered upon bed regeneration.

Abstract: The flow rate of a nonadsorbed product gas stream from a multiple unit PSA plant can be reduced in response to a reduced product demand by isolating all units in the plant and inserting an idle step into the adsorption cycle immediately following bed equalization steps of the cycle. In a preferred embodiment, the duration of the idle step is inversely proportional to the percentage reduction in the product demand. To maintain the product gas purity at the desired level, minor adjustments of the idle step duration can be made following adjustment to the idle step in response to a change in product demand.

Abstract: A container (10) for the storage of perishable foodstuffs is chilled by means of a liquefied gas comprising a mixture of oxygen and nitrogen which when totally vaporised has an oxygen concentration of between 15 and 22%, the remaining concentration being substantially of nitrogen. Such an atmosphere is breathable, and hence avoids the problems associated with non breathable chilling atmospheres.

Abstract: An air prepurification system which includes vertically oriented adsorption vessels containing, from top to bottom, a layer of moisture-selective adsorbent, a first layer of carbon dioxide-selective adsorbent and a second layer of carbon dioxide-selective adsorbent wherein the particle size of carbon dioxide-selective adsorbent in the second layer of carbon dioxide-selective adsorbent is smaller than the particle size of both the moisture-selective adsorbent and the carbon dioxide-selective adsorbent in the first layer of carbon dioxide-selective adsorbent. The air purification system is designed for use in a temperature swing adsorption process in which air is passed downwardly through the adsorption vessels during the adsorption step and upwardly through the vessels during the adsorbent regeneration step.

Abstract: Petrochemicals are produced by the vapor phase reaction of a hydrocarbon with air in the presence of a suitable catalyst. The petrochemical product is removed from the product gas stream, and unreacted hydrocarbon in part or all of the remaining gas stream is recovered by subjecting the gas stream to a TSA process in which the adsorbed hydrocarbon is desorbed at elevated pressure by purging the adsorbent with hot compressed air, the air being heated by compression. The compressed air-desorbed hydrocarbon mixture is recycled to the reactor.

Abstract: Hot exhaust gases from oxygen-based fossil fuel fired-furnaces made up predominantly of steam and carbon dioxide are used for reforming a hydrocarbonaceous substance in the presence or absence of oxygen to produce carbon monoxide and hydrogen. Additional hydrogen can be produced by subjecting the carbon monoxide produced in the reaction to the water gas shift reaction.

Abstract: Terephthalic acid is produced by reacting paraxylene with oxygen in a reactor having several vertical stages, the reaction taking place in the liquid phase using acetic acid as solvent and a cobalt-manganese-bromine complex catalyst. During the reaction, a carbon dioxide-containing gas phase is withdrawn from the vapor space of the reactor. The gas phase is cooled to condense vaporized acetic acid therefrom and carbon dioxide is separated from the gas phase and recycled to the vapor space or to the liquid phase or to both of these. In an alternate embodiment, the gas remaining after condensing acetic acid is subjected to catalytic oxidation to oxidize carbon monoxide and methane, if present, to carbon dioxide, and some or all of the carbon dioxide is recycled to the reactor.

Abstract: A therapeutic oxygen-nitric oxide gas mixture is produced by passing air, oxygen-enriched air or air containing a small amount of ammonia over a noble metal catalyst at an elevated temperature. The product gas containing nitric oxide and a small amount of nitrogen dioxide is passed through a bed of an adsorbent which preferentially adsorbs nitrogen dioxide to produce nitric oxide-containing air suitable for administering to humans as an inhalant.

Abstract: Sulfur compounds are removed from gaseous carbon dioxide by contacting the carbon dioxide with water vapor in the presence of a carbonyl sulfide hydrolysis catalyst, thereby converting carbonyl sulfide in the gas stream to hydrogen sulfide, contacting the resulting gas stream with ferric oxide, thereby removing hydrogen sulfide from the gas stream as elemental sulfur, and contacting the remaining gas stream with copper oxide, zinc oxide or mixtures of these, thereby removing any remaining sulfur compounds from the gaseous carbon dioxide.

Abstract: A hydrocarbon stream is cracked to produce a hot gaseous stream which is compressed and cooled to condense almost all of the hydrocarbons contained in the stream. A noncondensed stream remaining after the condensation step, comprised predominantly of hydrogen and C.sub.1 to C.sub.3 hydrocarbons, is subjected to pressure swing adsorption or temperature swing adsorption at an adsorption temperature of about 0.degree. to about 250.degree. C. in a bed of adsorbent which selectively adsorbs ethene and propene, thereby adsorbing substantially all of the ethene and propene from the gas stream. The ethene and/or propene is recovered upon bed regeneration. Higher alkenes are separated from alkanes by various methods.

Abstract: Hydrocarbon gas is separated from a gas mixture by concentration swing adsorption in a system consisting of a pair of adjacent adsorption beds that are contained in a cylindrical vessel and separated by a flat partition wall. The system is operated with the beds out of phase, such that one bed is in adsorption service while the other bed is regenerated by purging the bed with air. The pressure and temperature in the bed undergoing adsorption does not differ from the pressure and temperature, respectively in the bed being regenerated sufficiently to create significant stresses in the partition separating the beds.

Abstract: Nitric oxide is produced by reacting aqueous nitric acid with gaseous sulfur dioxide in a gas-liquid contact reactor. The reaction is conducted in the presence of a stoichiometric excess of nitric acid to minimize the production of byproduct nitrous oxide and nitrogen. The nitric oxide product gas is chilled sufficiently to freeze most of the water and byproduct nitrogen dioxide contained in the nitric oxide product gas. Residual nitrogen dioxide can be removed by adsorptive separation using an adsorbent which preferentially adsorbs nitrogen dioxide.

Abstract: A gas mixture comprised of nitric oxide and, optionally an inert gas, and containing small amounts of nitrogen dioxide, and perhaps moisture and sulfur dioxide, is purified by passing the gas stream through a bed of zeolite having a silica to alumina ratio not greater than about 200. The concentration of nitrogen dioxide, sulfur dioxide and moisture in the gas stream are reduced to about 1 ppm or less as the gas mixture passes through the bed of zeolite.

Abstract: A petrochemical is produced by the vapor phase reaction of a hydrocarbon with air in the presence of a suitable catalyst. The petrochemical is removed from the reactor effluent, and part or all of the remaining petrochemical-free gas stream is passed through a hydrocarbon-selective adsorbent, which adsorbs hydrocarbon from the gas stream, leaving a hydrocarbon-depleted waste gas. Hydrocarbon is purged from the adsorbent with air, and the air-hydrocarbon mixture is recycled to the partial oxidation reactor. The purge air, and preferably both the purge air and the petrochemical-free gas stream are dried by passage through beds of zeolite 3A prior to being introduced into the hydrocarbon-selective adsorbent, and the beds of zeolite 3A are regenerated by passing heated hydrocarbon-depleted waste gas therethrough.

Abstract: A process for recovering a given component from a first gas stream in which the given component is intermittently present by PSA or TSA using an adsorbent which more strongly adsorbs the given component by introducing into the first gas stream, prior to PSA or TSA treatment, a second gas stream that is enriched in the given component. The second gas stream may be introduced into the first gas stream only during periods when the concentration of given component in the first gas stream is below its maximum concentration or it may be continuously introduced into the first gas stream at a level which is greater than the maximum concentration of given component originally present in the first gas stream.

Abstract: In a pressure swing adsorption plant for the production of oxygen enriched gas a pressure vessel contains a first bed of molecular sieve adsorbent located adjacent an outlet 4 of the vessel which has an optimum operating efficiency at approximately ambient temperature and a second bed 10 of molecular sieve adsorbent which has an optimum efficiency below that of ambient operating temperature located adjacent the inlet 2.

Abstract: A pressure swing adsorption apparatus (10) is provided with actuator air via a reservoir (40) which draws its supply either from one or more of the process vessels (12) after it has been dried thereby or directly from the system compressor (32). Controls are provided to ensure actuator air is preferentially drawn from the dried source and for ensuring instrument air is available even on start up of the apparatus.