Abstract: High purity argon is produced by subjecting a two-phase liquid-vapor mixture containing up to 3 volume % of nitrogen and/or up to 5 volume % oxygen to cryogenic temperature swing adsorption in an adsorption bed containing one or more adsorbents selective for nitrogen and/or oxygen at a temperature between the bubble point and the dew point of the two-phase mixture.

Abstract: A method of rectifying a multicomponent mixture by pressure swing adsorption to separate primary and secondary components of the mixture. Two groups of adsorbent beds are used in the method and adsorbent beds of the two groups are employed in a paired relationship and subjected to feed, co-current depressurization, evacuation, and countercurrent repressurization stages. In the feed stages, pairs of the adsorbent beds are pressurized with the mixture to adsorb the primary component in a first group of the adsorbent beds and in an entry section of a second group of the adsorbent beds. Also during the feed stage, the secondary component is adsorbed in the second group of adsorbent beds in remaining sections thereof. During co-current depressurization, any of the secondary component adsorbed in the first group of adsorbent beds and part of the primary component is driven to the second group of adsorbent beds.

Abstract: A cryogenic rectification method for producing a product stream from a gaseous mixture having higher and lower volatility components and heavy impurities. In accordance with the method, the mixture is separated by a cryogenic rectification process employing one or more columns having plates, trays or packing for intimately contacting ascending vapor and descending liquid streams within the column. The mixture to be separated after having been compressed is combined with the recycle stream to produce a combined stream which is purified in a prepurification unit that is designed to remove the heavy contaminants. The combined steam is divided into major and minor streams. The major stream is then cooled and separated into liquid and vapor phases. Heavy impurities concentrate in the liquid phase taken as the recycle stream, which is then pumped to a high enough pressure for vaporization of the impurities. The resulting vapor is then reduced in pressure and combined with the incoming gaseous mixture.

Abstract: The present invention provides an apparatus and method for producing ultra-high purity nitrogen. In accordance with the method and apparatus, air is rectified to produce a tower overhead comprising high purity nitrogen rich in light elements, such as neon, helium and hydrogen. The tower overhead is then partially condensed within a condenser and separated into liquid and vapor phases within a phase separator. The liquid phase is lean in the light elements and the vapor phase is rich in the light elements. The liquid phase is removed from the bottom of the phase separator and is introduced into the column as reflux. As the reflux drops from tray to tray it is stripped of the light elements. A product stream containing ultra-high purity nitrogen is withdrawn as a liquid from the column after suitable stripping of the reflux. The product stream can be further purified by stripping the product stream within a stripper column.

Abstract: In the catalytic oxidation of isobutylene and/or tertiary butyl alcohol to methacrolein, the product methacrolein is recovered as an aqueous solution, which thereafter is stripped of methacrolein by contacting the solution with recycle gases from the subsequent oxidation of methacrolein to methacrylic acid. In a preferred embodiment, the oxidation reactor effluent gases are quenched to near ambient temperatures by direct contact with a recirculating stream of partially condensed effluent to provide an aqueous solution of methacrolein and thereafter the methacrolein remaining in the effluent gases is absorbed into a refrigerated water stream to provide a second aqueous solution. The aqueous solutions are combined and stripped by recycle gases, thereby supplying methacrolein as feed to the subsequent oxidation process.

Abstract: A gas recovery system primarily to recover propane and heavier hydrocarbons from a natural gas stream whereby separation is accomplished at lower pressures and higher temperatures normally required.