Abstract: A thermal sink is used to recover heat from a product gas leaving an adsorption vessel in a thermal swing adsorption process. Heat that is recovered from the product gas is used to heat a regeneration gas during the subsequent regeneration of the adsorbent material within the adsorption vessel. The step in which the regenerated bed of adsorbent material is cooled prior to returning to adsorption mode is eliminated.

Abstract: Disclosed is a process and apparatus for removing nitrogen compounds from an alkylation substrate such as benzene. A conventional adsorbent bed can be used to adsorb basic organic nitrogen compounds and a hot adsorbent bed of acidic molecular sieve can adsorb the weakly basic nitrogen compounds such as nitrites. Water facilitates the adsorption of the weakly basic nitrogen compounds. Running an alkylation substrate stream from a fractionation column of elevated temperature and suitable water concentration to the hot adsorbent bed may be advantageous.

Abstract: At lower temperatures an acidic molecular sieve adsorbent preferentially adsorbs water and basic organic nitrogen compounds over weakly basic organic nitrogen compounds such as nitrites. Elevated temperatures improve the capacity of acidic molecular sieve adsorbents to adsorb nitrites in the presence of water.

Abstract: Disclosed is a process and apparatus for removing nitrogen compounds from an alkylation substrate such as benzene. A conventional adsorbent bed can be used to adsorb basic organic nitrogen compounds and a hot adsorbent bed of acidic molecular sieve can adsorb the weakly basic nitrogen compounds such as nitrites. Water facilitates the adsorption of the weakly basic nitrogen compounds. Running an alkylation substrate stream from a fractionation column of elevated temperature and suitable water concentration to the hot adsorbent bed may be advantageous.

Abstract: A catalyst for the selective oxidation of hydrogen has been developed. It comprises an inert core such as cordierite and an outer layer comprising a lithium aluminate support. The support has dispersed thereon a platinum group metal and a promoter metal, e.g. platinum and tin respectively. This catalyst is particularly effective in the selective oxidation of hydrogen in a dehydrogenation process.

Abstract: A catalyst for the selective oxidation of hydrogen has been developed. It comprises an inert core such as cordierite and an outer layer comprising a lithium aluminate support. The support has dispersed thereon a platinum group metal and a promoter metal, e.g. platinum and tin respectively. This catalyst is particularly effective in the selective oxidation of hydrogen in a dehydrogenation process.

Abstract: A process for producing alkyl aromatics using a transalkylation reaction zone and an alkylation reaction zone is disclosed. One portion of the transalkylation reaction zone effluent passes to an alkylation reaction zone where an aromatic substrate is alkylated to the desired alkyl aromatic. At least a portion of the alkylation reaction zone effluent and another portion of the transalkylation reaction zone effluent pass to a product recovery zone. This process decreases the capital and operating costs of recycling aromatic substrate to the transalkylation and/or alkylation reaction zone while maintaining operational flexibility. This process is well suited for solid transalkylation and alkylation catalysts. Ethylbenzene and cumene may be produced by this process.

Abstract: A feedstream comprising nitrous oxide is purified by a pressure swing adsorption process employing a copurge with an oxygen-lean stream to produce a high purity nitrous oxide stream. The high purity nitrous oxide stream can be incorporated in a complex for the production of adipic acid to recover nitrous oxide from a dilute waste stream and pass the recovered nitrous oxide to a process for the production of phenol from an aromatic hydrocarbon. Unreacted nitrous oxide from the phenol production step acid can be recovered in a second, or vent PSA step, and combined with the recovery of byproduct nitrous oxide waste streams from the production of adipic for the overall recovery of nitrous oxide, thereby significantly reducing nitrous oxide emissions from the production of adipic acid.

Abstract: A process for the isomerization of hydrocarbons using a chloride promoted catalyst wherein an adsorption zone arrangement operates to maintain chloride compounds in the reaction zone and to prevent contamination of product streams with chloride compounds removes normal paraffins from the desorbent stream to extend the capacity and life of a clinoptilolite molecular sieve. The invention preferably uses isoparaffins recovered from the isomerization zone as a desorbent. A gaseous fraction of the isomerization zone effluent can be recovered to provide a desorbent containing a low concentration of normal paraffins.

Abstract: An adsorption arrangement in combination with a catalytic hydrocarbon conversion process suspends non-hydrocarbon materials that act to enhance the operation of the conversion zone by using an adsorption zone arrangement to keep the compounds in recirculation about the reaction zone. The process of this invention is particularly useful for the isomerization of hydrocarbons wherein the adsorption zone arrangement operates to maintain chloride compounds in the reaction zone and to prevent contamination of product streams with the chloride compounds. This invention can be used in combination with traditional adsorptive methods of removing contaminant from feedstreams that enter reaction zones. The invention is also useful for sulfided catalysts where it is desirable to maintain sulfur within the reaction zone and keep sulfur contamination from entering product streams.

Abstract: A process claimed for the removal of VOCs from fluid streams. The process comprises a vacuum swing adsorption zone containing at least 2 adsorption beds wherein the adsorbent beds are cocurrently purged with a diluent stream comprising an inert gas prior to a countercurrent evacuation step. In addition, the adsorbent beds may contain a first adsorption layer comprising an adsorbent selective for the adsorption of the inert gas, whereby the inert gas is retained within the VSA system to prevent the creation of an explosive mixture upon the condensation of the desorbed VOCs.

Abstract: A process claimed for the removal of VOCs from fluid streams. The process comprises a vacuum swing adsorption zone containing at least 2 adsorption beds wherein the adsorbent beds are cocurrently purged with a diluent stream comprising an inert gas prior to a countercurrent evacuation step. In addition, the adsorbent beds may contain a first adsorption layer comprising an adsorbent selective for the adsorption of the inert gas, whereby the inert gas is retained within the VSA system to prevent the creation of an explosive mixture upon the recovery of the desorbed VOCs.

Abstract: A process is provided for the removal and recovery of chlorine from a chlorine plant offgas stream. A pressure swing adsorption (PSA) process is used to remove from the chlorine plant offgas a vent gas stream comprising hydrogen and a tail gas stream comprising chlorine which is subsequently liquefied. The PSA zone comprises at least 2 adsorption beds, wherein each of the adsorption beds contains a weak adsorbent selective for the adsorption of chlorine and the PSA process is operated with a short cycle having an adsorption time of less than about 6 minutes. The vent gas withdrawn from the process is essentially free of chlorine and a liquefied chlorine product is recovered. The process provides an economic and efficient way of removing chlorine from a chlorine plant offgas stream without requiring a vacuum pump or heat removal equipment.

Abstract: The present invention provides a process for the recovery of methyl chloride from a mixture thereof with isobutane. The process employs pressure swing adsorption with a size selective adsorbent having a pore opening of between about 3.7.times.3.7 Angstroms and about 4.9.times.5.7 Angstroms, such as zeolite A, clinoptilolite and mixtures thereof to selectively adsorb methyl chloride from vent streams comprising methyl chloride and isobutane and recovering a tail gas stream enriched in methyl chloride. The process may be used in applications such as treating the vent gas streams from the direct synthesis of methyl chlorosilanes. The process provides an economical route to recovering a valuable raw material in the process of making silicones and reduces the volume and methyl chloride content of the vent stream which is typically incinerated to avoid the release of halogenated hydrocarbons to the atmosphere.

Abstract: A process claimed for the removal of VOCs from fluid streams. The process comprises a vacuum swing adsorption zone containing at least 2 adsorption beds wherein the adsorbent beds are cocurrently purged with at diluent stream comprising an inert gas prior to a countercurrent evacuation step. In addition, the adsorbent beds may contain a first adsorption layer comprising an adsorbent selective for the adsorption of the inert gas, whereby the inert gas is retained within the VSA system to prevent the creation of an explosive mixture upon the condensation of the desorbed VOCs.

Abstract: A process is provided for the removal and recovery of chlorine from a chlorine plant offgas stream. A pressure swing adsorption (PSA) process is used to remove from the chlorine plant offgas a vent gas stream comprising hydrogen and a tail gas stream comprising chlorine which is subsequently liquefied. The PSA zone comprises at least 2 adsorption beds, wherein each of the adsorption beds comprises a first adsorption layer and at least a second adsorption layer. The first adsorption layer contains a weak adsorbent selective for the adsorption of chlorine and has a large pore structure with 12 member rings or more. The second adsorption layer contains a strong adsorbent selective for the adsorption of chlorine and has a small pore structure with 10 member rings, or less. The vent gas withdrawn from the process is essentially free of chlorine.

Abstract: Mercury is often removed as an impurity from process fluid streams by adsorption in fixed beds using any of several well-known adsorbents having the ability to selectively adsorb mercury. It is also common to reintroduce this sequestered mercury into the environment by means of the spent gas used to periodically regenerate the fixed beds. A solution to this problem is provided by the present invention in which the mercury is removed from the process stream using a large cyclically regenerated adsorption bed in combination with a non-regenerable secondary adsorption bed, the mercury content of the former being in part recovered as liquid mercury by passage through a condenser and in part transferred to the non-regenerated bed. Mercury leakage from the non-regenerable bed is recycled to the cyclically regenerated bed.

Abstract: An adsorption arrangement in combination with a catalytic hydrocarbon conversion process suspends non-hydrocarbon materials that act to enhance the operation of the conversion zone by using an adsorption zone arrangement to keep the compounds in recirculation about the reaction zone. The process of this invention is particularly useful for the isomerization of hydrocarbons wherein the adsorption zone arrangement operates to maintain chloride compounds in the reaction zone and to prevent contamination of product streams with the chloride compounds. This invention can be used in combination with traditional adsorptive methods of removing contaminant from feedstreams that enter reaction zones. The invention is also useful for sulfided catalysts where it is desirable to maintain sulfur within the reaction zone and keep sulfur contamination from entering product streams.

Abstract: Processes are disclosed for the adsorption and isomerization of paraffinic hydrocarbons wherein an absorption cycle is employed that utilizes a non-adsorbable purge gas for regenerating the adsorber beds, which cycle includes adsorption, regeneration and void space purging steps and wherein one of said void space purging steps comprises passing an adsorber feed to the adsorber bed to purge non-adsorbable purge gas from the void space and said step is continued until at least a portion of the non-adsorbed hydrocarbons in the adsorber feed elutes from the void space of the adsorber bed. Processes are further disclosed for sulfur and/or ammonia-containing feeds that employ additional conversion and adsorption zones to prevent the sulfur and/or ammonia compounds from contacting the isomerization catalyst. The products from the processes are useful as motor fuel blending components.

Abstract: An isomerization zone process is disclosed that combines a deisohexanizer with a PSA separation section to provide a product stream comprising methylbutane and dimethylbutane. The process combines a methylpentane and normal hexane recycle stream, a normal pentane recycle stream and a fresh feedstream to provide a combined feedstream that is charged to an isomerization zone. The effluent from the isomerization zone is stabilized and passed to a deisohexanizer. A sidecut stream carries the methylpentane and normal hexane recycle stream from the deisohexanizer. Hydrocarbons having a higher boiling point than the sidecut stream are withdrawn as a bottoms stream from the deisohexanizer. An overhead carries normal pentane, methylbutane and dimethylbutanes to the PSA separation section. An extract stream is recovered as the normal pentane recycle stream. The raffinate from the PSA provides a high octane isomerate stream comprising mainly methylpentane and dimethylbutanes.