Mobil Oil Corporation

Exxonmobil Chemical Patents Inc.

Khushrav E Nariman

David L Johnson

David Lawrence Stern

John Scott Buchanan

Robert A Ware

J Scott Buchanan

Nazeer A Bhore

Stephen Harold Brown

David H Olson

William Alois Weber

Amos A Avidan

Reuel Shinnar

Larry Arthur Green

Mark F Mathias

There is provided a process for converting methanol and/or dimethyl ether to a product containing C to C olefins which comprises the step of contacting a feed which contains methanol and/or dimethyl ether with a catalyst comprising a porous crystalline material. The contacting is conducted in the presence of a cofed aromatic compound under conversion conditions including a temperature of about 350&deg; C. to about 550&deg; C. and a methanol and/or dimethyl ether partial pressure less than or equal to 50 psia (345 kPa). The porous crystalline material used in the catalyst has a pore size greater than the critical diameter of the aromatic compound and a Diffusion Parameter for 2,2-dimethylbutane of about 0.1 to about 26 sec when measured at a temperature of 120&deg; C. and a 2,2- dimethylbutane pressure of 60 torr (8 kPa), and the aromatic compound is capable of alkylation by the methanol and/or dimethyl ether under said conversion conditions.

Process for producing light olefins

A hydrocarbon feed containing C,C,olefins and/or paraffins is converted to light olefins, by contacting the feed with a catalyst containing ZSM-,and/or ZSM-,having an initial silica to alumina ratio greater than about,and phosphorus.

Catalytic production of light olefins rich in propylene

This invention is directed to an improved process for conversion of H2S to sulfur, using MOST(Mobil Offgas Sulfur Treatment) catalyst or sorbent. The sorbent is typically a magnesium-aluminate spinet, with oxidation promoters such as ceria and vanadia. H.sub.2 S from the feed gas is used to regenerate sulfated sorbent, simultaneously producing elemental sulfur which is then condensed out. The improvement involves combusting part of the feed, converting some of the feed H.sub.2 S to SO.sub.2 prior to contacting the sulfated sorbent. Thus much of the stoichiometric oxygen required for conversion of H.sub.2 S to S is supplied in the form of SO.sub.2 by this pre-combustion step, instead of coming totally from the oxidized/sulfated solid sorbent. This can decrease the amount of sorbent required, as well as the frequency of regenerations, thus reducing process cost. The hot combustion gas also helps to heat the feed stream. One or more Claus reactors may optionally be added, to further increase sulfur recovery efficiency.

Process for treating H.sub.2 S containing streams

This invention describes a process for the scrubbing of sulfur oxides from the effluent of conventional wet lime/limestone SOx reduction processes in coal or oil-fired plants. The sulfur oxides are oxidatively sorbed onto solid sorbents such as magnesium aluminate spinel. Reduction with the appropriate reducing gases (such as hydrogen) regenerates the catalyst, also yielding a process stream concentrated in SOx. This concentrated SOx stream can then be refed to the front end of the coal or oil-fired plants, with the SOx thus produced ultimately being removed in the conventional wet scrubbing technology.

Process for the reduction of SO.sub.2 from wet lime/limestone tailgas in

This invention is directed to an improved process for conversion of H.sub.2 S to sulfur, using MOST(Mobil Offgas Sulfur Treatment) catalyst or sorbent. The sorbent is typically a magnesium-aluminate spinel, with oxidation promoters such as ceria and vanadia. H.sub.2 S from the feed gas is used to regenerate sulfated sorbent, simultaneously producing elemental sulfur which is then condensed out. The improvement involves recycling a portion of the effluent from a downstream burner to mix with the feed to the sorbent. Thus some of the stoichiometric oxygen required for conversion of H.sub.2 S to S is supplied in the form of SO.sub.2 by this pre-combustion step, instead of coming totally from the oxidized/sulfated solid sorbent. This can decrease the amount of sorbent required, as well as the frequency of regenerations, thus reducing process cost. The hot recycle gas also helps to heat the feed stream.

Process for treating H.sub.2 S-lean streams, with recycle of SOx from

A dry, regenerable solid oxide process directed to convert SO.sub.x from the flue gas stream from a power plant, a coal or oil-fired plant or process heat furnace, or an FCC regenerator to elemental sulfur without using a Claus unit, a hydrogen plant, a regeneration gas separation system, or a hydrogenation section. This dry, regenerable solid oxide process is also effective on Claus plant tail-gas. This process uses solid oxides, such as, for example, magnesium aluminates or spinels to remove sulfur oxides from flue gas streams. The solid oxide is then regenerated by a reducing gas to release the sulfur compounds contained on the solid oxide to produce a gas stream comprising hydrogen sulfide, sulfur oxides and elemental sulfur. The elemental sulfur is then condensed and recovered as a product and the resulting gas stream may be recycled to be reprocessed over the solid oxide.

Process scheme for SO.sub.x  removal from flue gases

There is provided a process directed to the use of gases containing or mixed with carbon monoxide, such as synthesis gas, to aid in the regeneration of sulfur oxide-sorbed solid oxides, such as magnesium aluminates or spinels. This process is especially useful in applications where the solid oxide is used to purify the flue gas stream from an FCC regenerator, coal or oil-fired plant, power plant or process heat furnace, or the tail gas from a Claus plant. The process is also useful to remove sulfur oxides from flue gases produced in solid fuel combusters. According to this invention, carbon monoxide may be used alone or in combination with other gases to make the regeneration of the solid oxide exothermic or less endothermic, thereby improving the effectiveness of the regeneration.

Sox sorbent regeneration

A method and system useful for the removal of contaminants such as sulfur oxides from waste gas streams using a graded-bed system is disclosed. The graded-bed system uses beds with solid sorbents of two or more particle sizes in separate sections of the bed. In one embodiment, the solid sorbents are arranged so that the larger sorbent particles are disposed in the entrance region of the graded-bed system. In operation, a waste gas stream is passed over and through the solid sorbents so that contaminants, such as sulfur oxides and/or nitrogen oxides are adsorbed. The sorbent bed is then contacted with a reducing gas to desorb the sulfur oxides.

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Lawrenceville, NJ, United States of America

Khushrav E Nariman