Mobil Oil Corporation

Exxonmobil Oil Corporation

Gerald J Teitman

Joseph F Sodomin, Iii

John Scott Buchanan

David O Marler

Mark F Mathias

Joseph A Herbst

David L Johnson

Jeffrey C Trewella

Ajit V Sapre

Timothy L Hilbert

Catherine L Markham

Ronald J Cimini

Salvatore T Viscontini

Mohsen N Harandi

Stuart Damon Hellring

David Lawrence Stern

Scott A Stevenson

Albin Huss, Jr

Amos A Avidan

Nick Allen Collins

Michael E Landis

Hye Kyung Timken

Roger A Morrison

Reuel Shinnar

David L Fletcher

Roland H Heck

David A Pappal

Raghu K Menon

Paul P Durand

Harry A McVeigh

Stephen J McCarthy

Steven W Sparks

Tom Reischman

David W Rumsey

David H Parsons

A process and system is disclosed for removing sulfur from tail-gas emitted from a Claus sulfur recovery process. First, the tail-gas is oxidized so as to convert sulfur therein to sulfur oxides. Oxidized tail-gas is directed into an absorber where a solid absorbent absorbs substantially all the sulfur oxides thereon. After allowing sufficient time for a desired amount of sulfur oxides to be absorbed, absorption is ceased. Next, the solid absorbent containing the absorbed sulfur oxides is contacted with a reducing gas so as to release an off gas containing hydrogen sulfide and sulfur dioxide. Upon releasing sulfur from the solid absorbent, the solid absorbent is regenerated and redirected into the absorber. Sulfur in the off gas emitted by regeneration is concentrated to an extent sufficient for use within a Claus sulfur recovery process for conversion to elemental sulfur. By combining this process with a Claus sulfur recovery process, sulfur dioxide emissions can be reduced to less than about two parts per million.

Process and system for desulfurizing a gas stream

Low sulfur gasoline is produced from an olefinic, cracked, sulfur-containing naphtha by treatment over an acidic catalyst, preferably an intermediate pore size zeolite such as ZSM-5 to crack low octane paraffins and olefins under relatively mild conditions, with limited aromatization of olefins and naphthenes. This is followed by hydrodesulfurization over a hydrotreating catalyst such as CoMo on alumina. The initial treatment over the acidic catalyst removes the olefins which would otherwise be saturated in the hydrodesulfurization, consuming hydrogen and lowering product octane, and converts them to compounds which make a positive contribution to octane. Overall liquid yield is high, typically at least 90 percent of higher. Product aromatics are typically increased by no more than 25 weight percent relative to the feed and may be lower than the feed.

Hydrocarbon upgrading process

At least one olefin and at least one isoparaffin are converted to a diesel fuel blending component by contacting the olefin and the isoparaffin with a catalyst selected from MCM-22, MCM-36, MCM-49, and MCM-56 to provide a product containing a diesel fuel.

Process for producing low aromatic diesel fuel with high cetane index

A process for integration of a steam reforming unit and a cogeneration power plant in which said steam reforming unit comprises two communicating fluid beds; the first fluid bed comprising a reformer containing catalyst and which is used to react steam and light hydrocarbons at conditions sufficient to produce a mixture comprising synthesis gas hydrogen, carbon monoxide, and carbon dioxide, the second fluid bed comprising a combustor-regenerator which receives spent catalyst from the first fluid bed and which provides heat to heat the catalyst and balance the reaction endotherm, by combusting fuel gas in direct contact with the catalyst producing hot flue gas; said cogeneration power plant comprises a gas turbine equipped with an air compressor and a combustor; said integration which comprises drawing off a portion of compressed air from the power plant gas turbine air compressor leaving remainder compressed air; introducing the drawn off compressed air to the combustor-regenerator; mixing the hot flue gas from the combustor-regenerator with the remainder of the compressed air to produce a recombined gas stream and feeding this recombined gas stream to the combustor of the cogeneration gas turbine power plant.

Integration of steam reforming unit and cogeneration power plant

There is provided a process for the catalytic production of hydrogen from the reaction of hydrogen sulfide and carbon monoxide with the elimination of the carbonyl sulfide and/or sulfur dioxide by-products. The carbonyl sulfide and the sulfur dioxide are combusted or reacted in one or more reaction steps with each other, oxygen and/or hydrogen sulfide to produce carbon dioxide, water, sulfur or sulfuric acid or a combination of these.

Catalytic production of hydrogen from hydrogen sulfide and carbon

Removing sulfur oxide, carbon monoxide and nitrogen oxide in a flue gas stream by combusting fuel in the combustor with a reduced amount of oxygen to convert all sulfur-containing species in the flue gas stream to sulfur oxide, and to partially convert carbon monoxide therein to carbon dioxide, thus forming a sulfur oxide enriched gas stream having between at least about 500 ppm carbon monoxide and a consequential reduced amount of nitrogen oxide. The sulfur oxide enriched gas stream is contacted with a solid adsorbent bed for adsorbing the sulfur oxides in the form of inorganic sulfates and/or sulfur oxides. The solid adsorbent contains a catalytic oxidation promoter for oxidizing the carbon monoxide gas stream to carbon dioxide, thus forming a sulfur oxide and carbon monoxide depleted stream with the consequential reduced amount of nitrogen oxide for disposal. The adsorbent bed is then contacted with a reducing gas stream for regenerating the adsorbent bed to form a hydrogen sulfide and/or sulfur dioxide bearing stream.

Removing SOx, CO and NOx from flue gases

Removing sulfur oxide and carbon monoxide in a flue gas stream by combusting fuel in the combustor with a reduced amount of oxygen to partially convert carbon monoxide therein to carbon dioxide and sufficient to convert all sulfur-containing species in the flue gas stream to sulfur oxide and thus form a sulfur oxide enriched gas stream having between at least about 500 ppm carbon monoxide. The sulfur oxide enriched gas stream is contacted with a solid adsorbent bed for adsorbing the sulfur oxides in the form of inorganic sulfates and/or sulfur oxides. The solid adsorbent contains a catalytic oxidation promoter for oxidizing the carbon monoxide gas stream to carbon dioxide, thus forming a sulfur oxide and carbon monoxide depleted stream for disposal. The adsorbent bed is then contacted with a reducing gas stream for regenerating the adsorbent bed to form a hydrogen sulfide and/or sulfur dioxide bearing stream.

Removing SO.sub.x, NO.sub.X and CO from flue gases

A multi-bed process of removing sulfur oxides and/or other combustible sulfur-containing compounds from a gas stream including combusting the other combustible sulfur-compounds when present in the gas stream with air or oxygen to convert such sulfur-containing compounds to sulfur oxide and form a sulfur oxide enriched gas stream. The sulfur oxide enriched gas stream is contacted with first and second serially connected solid adsorbent beds for adsorbing the sulfur oxides in the form of inorganic sulfates and/or sulfur oxides. A third adsorbent bed is contacted with a reducing gas stream to regenerate the bed by reducing the retained inorganic sulfates and/or sulfur oxides to hydrogen sulfide and/or sulfur dioxide, to thereby form a hydrogen sulfide and/or sulfur dioxide bearing stream. The feeds to each of the beds are realigned to place the second and third beds in series with the sulfur oxide and/or sulfur dioxide enriched stream being fed to the second bed and to place the first bed in a regenerative mode. Thereafter, the foregoing steps are repeated whereby each of the three beds are sequentially placed in an initial bed mode in the series, a regenerative mode, and a second bed mode in the series.

Desulfurizing a gas stream

Catalytically cracked naphthas containing C.sub.9 + hydrocarbons are hydrocracked over a crystalline zeolite, typically, mildly steamed zeolite beta then subjected to reforming to achieve a gasoline product of reduced end boiling range and higher octane than the feed. A hydrogen stream from the reformer which contains a catalytic promoter, such as chlorine, is separated into a first stream and a second stream. The first stream is treated over a solid sorbent to remove the promoter and recycled promoter to the hydrocracking step while the untreated second hydrogen stream which contains promoter is recycled to the reformer.

Heavy naphtha conversion

A fluidized catalytic cracking process and apparatus with an active bed annular spent catalyst stripper is disclosed. An annular catalyst stripper disposed about a riser reactor is separated, by a baffle or fluid flow, into a secondary stripper nearer the catalyst regenerator and a primary stripper on the far side of the annular stripper from the regenerator. Catalyst flows through the primary stripper as a dense bed, to a transport means which lifts catalyst to the inlet of the secondary stripper. The 'dead' region on side of annular strippers far from the regenerator is eliminated. Preferably catalyst is added to the primary stripper via cyclone diplegs, and a cyclone is used on the transport outlet.

Active bed fluidized catalyst stripping

A sulfur-containing catalytically cracked naphtha is upgraded to form a low-sulfur gasoline product by a process which retains the octane contribution from the olefinic front end of the naphtha. Initially, the mercaptan sulfur in the front end of the cracked naphtha is converted to higher boiling disulfides by oxidation. The front end, which is then essentially an olefinic, high octane sulfur-free material, may be blended directly into the gasoline pool. The back end, which now contains the original higher boiling sulfur components such as thiophenes, together with the sulfur transferred from the front end as disulfides, is hydrotreated to produce a desulfurized product. This desulfurized product, which has undergone a loss in octane by saturation of olefins, is then treated in a second stage, by contact with a catalyst of acidic functionality, preferably a zeolite such as ZSM-5, under conditions which produce a product in the gasoline boiling range of higher octane value. Because this second product may contain combined organic sulfur, it may be subjected to a final desulfurization to reduce organic sulfur to acceptable levels.

Gasoline upgrading process

Oxides of nitrogen (NO.sub.x) emissions from an FCC regenerator are reduced by forcing the regenerator to operate between full and partial CO burn mode. Operating with less than 1 mole % O2 and up to 1 or 2% CO in the flue gas creates conditions which oxidize nitrogen compounds in coke on spent catalyst to NOx, and simultaneously convert NOx in the regenerator to nitrogen. A downstream CO boiler can burn this low CO flue gas without producing large amounts of NOx. Most NOx emissions can be eliminated. An apparatus, with the regenerator air:coke ratio controlled by both CO and O2 analyzers monitoring regenerator flue gas, is also disclosed.

FCC of nitrogen containing hydrocarbons and catalyst regeneration

A refinery derived spent caustic is recycled by introducing the spent caustic to a delayed coking drum while conducting delayed coking of a hydrocarbon feedstock. The alkali metal containing material accelerates coking, induces production of shot coke, alleviates the problem of a hot drum and reduces drum cooling time.

Delayed coking with refinery caustic

A used lubricant oil recycling process is disclosed in which a used lubricating oil is injected to a delayed coker downstream of the coker furnace whereby the used oil is thermally cracked into hydrocarbon fuel products which are low in metal contaminants, sulfur and nitrogen. The used lubricant can be preheated in an independent heater to avoid a quenching effect of the process stream when added in an amount greater than about 3% by volume based on the entire volume of the feed.

Process of used lubricant oil recycling

A catalytic cracking process operates with enhanced stripper efficiency by subjecting spent catalyst to microwave radiation before catalyst regeneration. Preferably the microwave frequency is one which ignores the catalytic cracking catalyst and preferentially excites the hydrocarbon or coke on the spent catalyst, the stripping steam conventionally used, or both the stripping steam and the hydrocarbonaceous coke. In preferred embodiments, microwave frequencies are used which are selective for various impurities in the coke, such as sulfur and/or nitrogen impurities. Additives, such as ferrous materials, may be added to augment the efficiency of desulfurization during stripping. The process is applicable to fluidized catalytic cracking and moving bed catalytic cracking units.

Growing community of inventors

Vienna, VA, United States of America

Gerald J Teitman