Abstract: A process is disclosed for the production of methanol from a synthesis gas stream comprising hydrogen and carbon dioxide in which an equilibrium reaction to methanol is achieved by conducting the reaction and the product separation in a pressure swing adsorption and reaction zone containing a uniformly distributed adsorbent for the selective adsorption of methanol and a catalyst for the equilibrium conversion of the synthesis gas to methanol. More specifically, the process achieves the production of methanol by the reaction of the hydrogen and the carbon oxide with the simultaneous adsorption of the product at the same temperature and pressure. The passing of the synthesis stream to the bed is terminated and the bed is purged and depressurized to desorb the methanol product. In one embodiment, the bed is cocurrently purged with at least a portion of an effluent stream prior to depressurizing the bed.

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 The vent gas withdrawn from the process is essentially free of chlorine and a liquefied chlorine product is recovered.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 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: A spiral-wound adsorber module is claimed for the removal of VOCs from fluid streams. The apparatus comprises a spirally adsorbent bed supported within a cylinder to provide a compact, longer adsorbent life alternative for a thermal swing adsorption process.

Abstract: A process for recovering hydrogen-rich gases and increasing the recovery of liquid hydrocarbon products from a hydrocarbon conversion zone effluent is improved by a particular arrangement of a refrigeration zone, a pressure swing adsorption (PSA) zone, and up to two separation zones. The admixing of at least a portion of the tail gas from the PSA zone with a hydrogen-rich gas stream recovered from a first vapor-liquid separation zone results in significantly improved hydrocarbon recoveries and the production of a high purity hydrogen product. The process is especially beneficial in the integration of the catalytic reforming process with vapor hydrogen consuming processes such as catalytic hydrocracking in a petroleum refinery.

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 at least two cyclically regenerated adsorption beds in combination with a condenser whereby upon regeneration of one bed, the regeneration stream effluent therefrom is treated in the condenser to recover the bulk of the mercury as liquid mercury and recycling the overhead from the condenser to another bed engaged in the adsorption-purification of fresh feedstock.

Abstract: An integrated process for treating a vent gas stream containing halogenated organic compounds to produce a clean vent gas with vacuum swing adsorption of the halogenated organic compounds and the recycle of a gaseous stream from the halogenated organic compound recovery section. A liquid sponge oil containing halogenated organic compounds is contacted and admixed with the evacuated effluent from the adsorption zone to prevent the accumulation of normally gaseous hydrocarbonaceous compounds.

Abstract: Pressure swing absorption processes are disclosed which employ a standard pressure swing absorption cycle comprising the steps of adsorption, one or more cocurrent depressurization steps for equalization or providing purge gas, a countercurrent depressurization step, a countercurrent purge step, and repressurization steps. The processes of the present invention also include an additional countercurrent desorption step performed in conjunction with the first countercurrent desorption step at above atmospheric pressure and a countercurrent purge step at about the adsorption temperature which can provide increased capacity and recovery as compared to PSA processes that only have one countercurrent depressurization step or otherwise do not have a countercurrent purge step.

Abstract: A process is provided for the separation of ethane from methane-containing feedstreams using pressure-swing adsorption wherein the adsorbent is a faujasite type of zeolitic aluminosilicate containing at least 20 equivalent percent of calcium cations or zinc cations or mixtures thereof and containing not more than 80 equivalent percent of alkali metal or alkaline earth metal cations.

Abstract: A process for the removal of organic halide compounds from an effluent waste gas wherein the waste gas is sequentially compressed to separate water vapor and organic halide compounds, and to contact the resulting compressed gas having a reduced concentration of organic halide compounds with an adsorbent to produce an effluent waste gas containing essentially no detectable quantities of organic halide compounds.

Abstract: A process is provided for the separation of ethane from methane-containing feedstreams using pressure-swing adsorption wherein the adsorbent is a faujasite type of zeolitic aluminosilicate containing at least 20 equivalent percent of at least one cation species selected from the group consisting of zinc, rare earth, hydrogen, ammonium and calcium and containing not more than 80 equivalent percent of alkali metal or alkaline earth metal cations other than calcium.