Abstract: For the removal of trace quantities of iodine-containing contaminants from corrosive liquid feed streams, an adsorbent with distinct advantages over prior-art materials is provided. The treatment method involves the use of a suitable, silica-rich zeolite which has been cation-exchanged with an iodine-reactive metal. This inorganic adsorbent may be used in unbound form, or it can bound with a substantially insoluble porous inorganic refractory metal oxide binder. Reactivation and regeneration techniques, which are generally incompatible with prior-art adsorbent materials, are also disclosed.

Abstract: A process is provided for the removal of trace amounts of aromatic hydrocarbons from an acid waste gas feed stream comprising sulfur compounds and the aromatic hydrocarbons. An adsorption process employing an adsorbent such as a high silica zeolite adsorbent having a framework silica-to-alumina ratio greater than about 15 and having a pore size greater than about 6.2 angstroms is used to remove from the feed gas mixture aromatic hydrocarbon contaminants and permit the recovery of a high purity sulfur product from the treated effluent stream. The use of the present invention removes aromatic hydrocarbon contaminants which are responsible for the degeneration of the performance of the downstream sulfur recovery zone.

Abstract: A process is provided for the removal of trace amount of aromatic hydrocarbons from a waste feed gas stream comprising sulfur compounds and the aromatic hydrocarbons. An adsorption process employing an adsorbent such as a high silica zeolite adsorbent having a framework silica to alumina ratio greater than about 15 and having a pore size greater than about 6.2 Angstroms is used to remove from the feed gas mixture aromatic hydrocarbon contaminants and permit the recovery of a high purity sulfur product from the treated effluent stream. The adsorption zone comprises at least 2 adsorption beds wherein one of the first adsorption beds is operating in an adsorption mode and the other is being regenerated at a desorption pressure higher than the adsorption pressure. The regeneration is performed in a closed system or partially closed system, and prior to returning a regenerated adsorption zone to adsorption conditions the waste feed gas stream is used to cool and purge the regenerated zone.

Abstract: The invention relates to a process for removing and recovering mercury, an impurity, from a hydrocarbon feedstream. The process comprises separating the hydrocarbon feedstream into a gaseous portion and a liquid hydrocarbon portion and separately treating the gaseous and liquid portions by adsorption in separate purifier beds. The gas and liquid purifier beds are regenerated sequentially with a heated regenerant stream that following desorption and recovery of mercury is further purified in a secondary regenerable adsorption bed. The sequential regeneration of the two separate purifier beds and the secondary adsorbent bed significantly reduces the capital and operating cost for the process and serves to concentrate the mercury in the secondary adsorbent bed where it can be removed at a lower cost.

Abstract: A process is provided for the removal of heavy hydrocarbons from a feed gas mixture. An adsorption process employing a high silica zeolite adsorbent having a silica to alumina ratio greater than about 20 and having a pore size greater than about 4.5 Angstroms is used to remove from the feed gas mixture heavy hydrocarbon contaminants and permit the further treatment of the feed gas for the bulk removal of carbon dioxide. The adsorption zone comprises at least 2 adsorption beds wherein one of the first adsorption beds is operating in an adsorption mode and the other is being regenerated. The effluent from the adsorption zone, depleted in heavy hydrocarbons is passed to a membrane treating zone to provide a non-permeate stream depleted in carbon dioxide. At least a portion of the non-permeate stream is heated and the heated non-permeate stream is used to regenerate the adsorption zone.

Abstract: Liquid phase hydrocarbon fractions of wet natural gas streams which have been in contact while in the liquid phase with mineral particles entrained in the natural gas stream as it is recovered from the wellhead are found to contain a suspension of such particles. These particles contain loosely bound mercury which is capable of contaminating other constituents of the natural gas stream which come into contact with the particles. Effective procedures to purify such wet natural gas streams must include removal of the mineral particles as well as the element mercury dissolved in the liquid phase hydrocarbons or admixed with the vapor phase hydrocarbons.

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: In the purification of natural gas streams to remove mercury by adsorption procedures, environmental pollution is avoided by using a condenser in conjunction with the adsorption beds in a manner such that the mercury vapor contained in the purge gas used to regenerate the adsorption beds is covered entirely as a liquid rather than being vented from the purification system as mercury vapor.

Abstract: In processes for removing mercury vapor from natural gas streams by selective adsorption in fixed adsorbent beds, water is invariably adsorbed along with the mercury impurity. During the periodic purge regeneration of the adsorbent bed it is desirable to recover as much as possible of the desorbed mercury in the spent regeneration gas in liquid form to avoid reintroducing the mercury into the environment. Cooling this spent regeneration gas under the high pressure conditions involved to condense the mercury can result in the highly undesirable formation of hydrocarbon hydrates if temperatures low enough to condense an adequate amount of mercury are employed. In the process of the present invention, the spent regeneration gas stream, from which some mercury has been removed by cooling, is further treated in a desiccant bed so that it is possible to cool it further in order to condense and remove additional mercury without encountering hydrocarbon hydrate formation.

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: A process is disclosed for improving catalyst performance and yields in the manufacture of motor gasoline components. More particularly the process is directed to the removal of H.sub.2 S, sulfur compounds, trace amounts of acetonitrile or acetone or propionitrile from a hydrocarbon feedstock, comprising a C.sub.3 -C.sub.5 product fraction from a fluid catalytic cracking unit which may be used subsequently in an etherification process for the production of ethers such as MTBE and TAME and/or an alkylation process for the production of alkylate. The hydrocarbon feedstock is passed to an amine treating zone, a mercaptan sulfur removal zone and an adsorption zone for the removal of sulfur compounds, water and trace amounts of acetonitrile or acetone or propionitrile. The regeneration of the adsorption zone includes the contacting of the sorbent with a heated regenerant vapor stream. The spent regenerant vapor stream is condensed to provide a hydrocarbon phase and an aqueous phase.

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 non-regenerated adsorption bed in combination with a periodically regenerated secondary adsorption bed, the mercury content of the latter being transferred to the former during the regeneration procedure.

Abstract: Processes are disclosed for separating water and carbon dioxide from hydrocarbon streams, e.g., natural gas, by adsorption prior to low temperature hydrocarbon processing operations, e.g., liquid natural gas recovery and nitrogen rejection. The processes employ separate adsorption zones for the water and carbon dioxide adsorption and both adsorption zones are operated with a thermal swing adsorption cycle. A product gas from the low temperature processing operation, e.g., methane, can be used as the purge gas for one or both adsorption zones and the desorbed water and carbon dioxide, along with the purge gas can be recovered and introduced into a natural gas pipeline, for example.

Abstract: Mercury is selectively removed to very low levels of concentration from fluid streams such as natural gas, cracked gas, hydrogen or naphtha by passage of the stream through an adsorbent bed containing particles of a zeolitic molecular sieve having pore diameters of at least 3.0 Angstroms and in which the zeolite crystallites forming the outer shell of the adsorbent particle to a depth of not greater than about 0.1 millimeter into the adsorbent particle, contain ionic or elemental silver. These adsorbent particles are utilized to particular advantage in a compound adsorbent bed containing a desiccant substantially free of silver through which a fluid stream containing both mercury vapor and water vapor is both dried and purified with respect to mercury by passage therethrough, coupled with periodic regeneration of both media using conventional purge desorption methods.