DE2657300A1 - Cyclic fluidised cracking process using zeolite catalyst - with metal component giving reduced emission of harmful gases (NL 21.6.77) - Google Patents

Abstract

Cyclic fluidised cracking process for S-contg. oils, using (1) a catalyst of molecular sieve type, in which is incorporated during the cracking process, (2) Mg, Ca, Sr and/or Ba in free or combined form, as fluidisable solid particles or asan oil- or water-soluble cpd. Content of (1) in the catalyst is 10-99.9975 (90-99.9) wt.% and amount of (2) is sufficient to absorb at least 50% of the SO2 formed in the regenerator. In the process, (a) a catalyst mixt. as above is made, (b) the charge is cracked at 454-649 degrees C, (c) the deactivated catalyst is stripped at 454-649 degrees C, using a gas contg. steam in wt.r atio to (1) of 0.0005-0.025, (d) the catalyst is regenerated at 566-788 degrees C, (e) at least 50% of the sulphur oxides is absorbed by the catalyst, (f) the catalyst is recycled to the reactor, (g) a waste gas is drawn off from the regenerator contg. O2 and a low concn. of sulphur oxides, and (h) most of the absorbed SO2 is drawn off from the reactor and/or stripper as S-contg. gas, e.g. H2S. Incorporation of (2) during cracking instead of during prepn. of the catalyst gives a greater reduction in SO2 emission from the regenerator. The cracking process can be controlled by varying the rate or amount at which (2) is added, and it is deposited on the outside or on accessible area of the catalyst.

Description

Catalytic cracking process with reduced emissions

of harmful gases The invention relates to a cyclic catalytic Cracking process in fluid or fluidized phase, which is used on sulfur containing hydrocarbon feeds is suitable and at a substantial rate Reduction of the emissions of sole monoxide and sulfur oxides in the regenerator exhaust gases leads.

A cracking catalyst created by the deposition of carbonaceous Deposits, commonly called "coke", during cracking of coals: hydrogen has become relatively inactive in the reaction zone continuously withdrawn from the reaction zone. Such a spent catalyst is transferred from the reaction zone into a stripping or

Strip zone where strippable carbonaceous deposits, namely hydrocarbons, washed off by the catalyst, which in turn is passed into a regeneration zone, where the activity of the catalyst through distance of non-washable carbonaceous debris by burning the coke in an oxygen-containing gas to form Carbon monoxide and carbon dioxide is restored, the hot regenerated catalyst is then continuously returned to the reactor to complete the cycle repeat.

In the case of catalytic cracking, problems arise due to the incomplete Combustion of carbon monoxide to carbon dioxide in the regeneration zone, thereby creating a considerable amount of carbon monoxide in the exhaust gases or flue gases of the regeneration zone remains. In addition to the undesirable discharge of carbon monoxide into the atmosphere carbon monoxide and residual oxygen tend to be in the exhaust gases of the regeneration zone zir reaction, as a result of which burning processes occur in lines and hose draw-offs of the system and such structures are damaged by excessive temperatures.

In addition, if contaminants containing high levels of sulfur,, h.

Petroleum hydrocarbon fractions, the organic sulfur compounds included, directed into an Oracking unit of the fluidized catalyst type, so the coke deposited on the catalyst contains sulfur. When regenerating of the coke-containing deactivated catalyst, the coke is removed from the catalyst surfaces burned down. In this combustion process, the sulfur that is present is turned into sulfur dioxide transferred together with a lower proportion of sulfur trioxide and thus arrives into the outflow of the regenerator zone exhaust gases. When cracking a high sulfur Feed material emissions of sulfur oxides often occur in the order of magnitude of about 1200 parts per million.

for carbon monoxide emissions and for particulate matter Standard Pollution Conditions were established, and soon for others too Exhaust gases, such as the sulfur oxides and in particular the sulfur dioxide, are to be degassed. Therefore, there has been a reduction in the emission content of various combustion products and particles from effluents from regeneration zones in connection a great deal of attention has been paid to petroleum cracking units. The ones for reducing The method chosen for such emissions must be chosen to be effective without reducing the activity and selectivity of the cracking catalyst. Also, the method chosen must not have some form of unwanted emission replace with another problem such as an increase in particle emission or an increase in operating costs. Based on these considerations, a desirable reduction in the emission of sulfur oxides in petroleum cracking units achieved by the use of an Orack catalyst, which in terms of a minimal Emission of both carbon monoxide and sulfur oxides is modified, with the catalyst activity, the stability and the abrasion resistance below usual Cracking conditions are maintained in either known or new cracking units.

It is true that the use of metals in cracking catalysts is generally avoided and it is considered problematic to have metalliferous charges in the presence to crack an orrack catalyst, but describe the South African patent specification 7924/72 and corresponding U.S. Patent 3,909,392, discussed in greater detail below related to the use of combustion catalysts or promoters with cracking catalysts within the regeneration zone, which have a metal rod, Grid or Mesh or a sieve in the combustion zone, as well as fluidizable Metal compounds, in particular powdered oxides of metals of the transition group, for example iron-III-oxide, manganese dioxide and the oxides of the rare earth metals which are added to the catalyst charge or to the regeneration vessel are limited. BE-PS 826 266 teaches a method similar to that of US-PS 3,909,392 which is to mine catalytic cracking catalyst in physical association with one that accelerates carbon monoxide oxidation To use a catalyst made of a metal with an atomic number of at least 20, metals of groups IB, IIB and III to 7-ill of the periodic table the Elements, in particular platinum, palladium, rhodium, molybdenum, tungsten, copper, chromium, Windings, manganese, cobalt, vanadium, iron, cerium, ytterbium and uranium are suitable oxidation promoters to be named. US-PS 3808 121 teaches the regeneration of a cracking catalyst in the presence of an oxidation catalyst for carbon monoxide in the regeneration zone is held.

BR-PS 7 412 423 describes a cracking catalyst that is less as 100 parts per million, calculated as metal based on the total catalyst, at least one metal component from the group of metals of periods 5 and 6 of Group VIII of the Periodic Table of the Elements, rhenium and compounds thereof which leads to a particularly impressive reduction in carbon monoxide levels in flue gases from catatypical cracking catalysts. This patent also includes a molecular sieve type catalyst produced in the sodium form, ion-exchanged with ammonium ions and then with metals the rare earth group is impregnated.

As for the emissions of sulfur oxides, there have been various Process for the treatment of exhaust gases or flue gases developed, such as washing or scrubbing, chemical absorption, neutralization and chemical reaction and Conversion, however, all of these methods require the removal of sulfur oxides extensive and expensive additional equipment, so that both the operational as well as the investment costs are increased. U.S. Patent 3,699,037 teaches the addition at least a stoichiometric amount of a calcium or magnesium compound, based on the amount of sulfur deposition on the catalyst, to the cracking cycle. This added material is said to react with the sulfur oxides and then in one finely distributed state from the Orack cycle as particulate material in the regenerator exhaust removed.

However, the continuous addition of such a material increases the running costs obvious. Similarly, U.S. Patent 3,030,300 covers and 3,030,314 a catalytic cracking process that results in a cracking process cycle with movable bed continuously one or more connections of boron, alkali metals and alkaline earth metals added who the so as to catalyst particles with an increased resistance to breakage by impact and to the To generate surface abrasion that contains a silicon or silicon dioxide include catalyst particles with a microporous catalytically active core, the is provided with an adhesive protective coating made of a glaze made of silicon dioxide and one or more compounds of boron, alkali metals and alkaline earth metals consists.

U.S. Patent 3,835,031 describes a cyclic catalytic cracking process in fluidized or swirled phase, in which a reduced emission of sulfur oxides is achieved in the regenerator exhaust. This process works with a catalyst which is a molecular sieve in a silica-alumina matrix or base comprises impregnated with one or more metal oxides of the Group IIA metals is. U.S. Patents 3,388,077; 3,409,390 and 3,849,343.

describe a process for effecting the transformation of a harmful Exhaust gas stream containing carbon monoxide and sulfur oxides. This procedure exists in contacting the stream with a catalytic composition, made of a porous refractory support material, a catalytically active metal component, for example a metal from the platinum group and an alkaline earth metal component, selected from the group of calcium, barium and strontium.

A new method has now been found.

The invention relates to a cyclic catalytic CracL process in a fluidized or swirled phase ("cyclic, fluidized catalytic cracking process11), which results in reduced emissions of sulfur oxides in the exhaust gases the regeneration zone can be achieved. In various embodiments, the Invention also to a substantially complete combustion of carbon monoxide in the Reaction zone and for the absorption of the during such Combustion evolved heat on solid particles that entered the reaction zone and the stripper zone or, stripping zone, before it goes to the regeneration zone to be led back.

Such solid particles comprise a molecular sieve type of cracking catalyst and a metallic reactant; they can also use an amorphous cracking catalyst and solids that are substantially inert to hydrocarbon cracking are include.

The metallic reagent can be used in the cracking catalyst of the molecular sieve type, incorporated the amorphous cracking catalyst and the substantially inert solid will. Such incorporation can be carried out either before or after the introduction of the particulate substrate can be made in the cycle of the cracking process. Such conditions are used in the cycle of the cracking process that a stable metal and sulfur containing compound in the solid particles in the regeneration zone and a sulfur-containing gas from the stripping zone respectively.

Stripper zone is withdrawn.

In the development of catalytic converters to reduce emissions of sulfur oxides in exhaust gases from the regeneration zone of a fluid cracking process it is important that such catalysts not only have the ability to to exercise a special function first, but that they also have the ability to to enable this in a satisfactory manner over longer periods of time. Therefore, when designing such catalysts, activity and stability characteristics must be taken into account attention should be paid to the catalysts. The activity in that sense is a measure of the ability of a catalytic converter to reduce emissions of sulfur oxides to reduce in the exhaust gases of the regeneration zone with a certain accuracy value, where the accuracy value means the conditions used, i.e. the temperature, the pressure, the contact time, etc. The stability of a catalyst is a measure of the ability of the catalyst the activity characteristics during to maintain a certain time. The stability relates to the temporal The amount of change in activity parameters, with a smaller amount being more stable Catalyst called. The stability should be such that the activity characteristics can be maintained for longer periods of operation.

These key features are more easily attainable when you look at the effective one Means for achieving reduced sulfur oxide emissions, according to the invention that metallic reagent, in the cracking process cycle and put it in situ in the solid particles rather than the molecular sieve type cracking catalyst to mix or assemble during the production of this cracking catalyst. It has been shown that the introduction or incorporation of the metallic reagent in the cracking process cycle as opposed to mixing with the cracking catalyst of the molecular sieve type during the preparation of the cracking catalyst to a larger one Reduction of sulfur oxide emissions in the exhaust gases from the regeneration zone. The addition of the metallic reagent to the cracking process cycle is also beneficial, there is a greater degree of control of a possible adverse effect of the metallic reagent on the cracking reaction is possible because the rate and / or the amount of such metallic reagent included in the cracking cycle is introduced, can be varied. Also can be a metallic reagent that beforehand with the cracking process cycle or

Cracking process catalyst was mixed with attrition of the cracking catalyst are lost in the form of fine particles. The addition of the metallic reagent to the Cracking process cycle and its introduction into the solid particles allows in situ maintaining a desired amount of metallic reagent on the outside or at accessible locations on the cracking catalyst.

The invention provides an improved cyclic catalytic cracking process in fluidized or swirled phase, in which a hydrocarbon feed, the organic sulfur compounds contains, an oak in a reaction zone under fluidizing or fluidized bed conditions with homogeneous or is subjected to non-homogeneous regenerable fluidized solid particles, those of a metallic reagent and a molecular sieve type cracking catalyst consist, which comprises a gray catalyst matrix, the crystalline aluminosilicate, distributed over the matrix, the gray catalyst containing sulfur carbonaceous deposits are deactivated at the same time. The whirled up Solid particles become from the cracked hydrocarbon effluent from the reaction zone separated and fed to a stripping or stripping zone, in which the deactivated Catalyst from the strippable carbonaceous deposits by contact is washed with a stripper gas. The fluidized solid particles are then separated from the gaseous effluent of the stripper zone and a regeneration zone fed, in which the stripped deactivated cracking catalyst by burning of the non-strippable sulfur-containing carbonaceous deposits of the stripped, deactivated cracking catalyst in contact with an oxygen containing gas stream is regenerated to a high activity, with carbon monoxide, Carbon dioxide and sulfur oxides are formed with the metallic reagent to form a compound containing metal and sulfur in the solid particles react. The fluidized resp.

fluidized solid particles that represent the regenerated cracking catalyst are separated from the exhaust gases or flue gases of the regeneration zone and returned to the reaction zone.

The improvement is to find a material that has a metal in the metallic reagent to be introduced into the cracking process cycle and the introduce metallic reagents into the solid particles within the cracking process cycle or to incorporate; by using a stripper gas that Contains steam; deactivated by regenerating the stripped or stripped Cracking catalyst at regeneration temperatures in the range in which the metal and containing sulfur Connection of solid particles stable is; and by creating sufficient oxygen in the regeneration zone in the oxygen-containing regeneration gas stream, so that exhaust gases, the molecular Containing oxygen, are withdrawn from the regeneration zone.

A suitable hydrocarbon feed for use in the Process can contain about 0.2 to about 6 weight percent sulfur in the form of organic sulfur compounds contain. The feed advantageously contains from about 0.5 to about 5 percent by weight sulfur and most advantageously from about 1 to about 4 percent by weight sulfur, the sulfur is in the form of organic sulfur compounds.

The matrix of the cracking catalyst of the molecular sieve type cracking catalyst is preferably a combination of at least two materials selected from the group of silicon dioxide, aluminum oxide, zirconium dioxide, titanium dioxide, magnesium oxide, Ghorlumdioxid and Boroxid® and especially silica-alumina. These Cracking catalyst matrix preferably contains from about 10 to about 65, especially about 25 to about 60 weight percent alumina; preferably about 35 to about 90, especially about 35 to about 70 weight percent silica; and by pulling about 0.5 to about 50, in particular about 5 to about 50 wt. crystalline aluminosilicate. The cracking catalyst of the molecular sieve type is preferably from about 10 to about 99.999, and especially preferably about 30 to about 99.995 and particularly preferably about 90 to about 99.995 % By weight of the solid particles.

The metallic reagent consists of at least one free or combined or bound metallic element, selected from the group of magnesium, calcium, Strontium and barium. Hence, the metallic reagent can be selected from the group of magnesium, calcium, strontium, barium, their compounds and the Mixtures of that. The metallic reagent is preferably chosen from the group of magnesium and calcium.

The oxide or oxides of the metallic element or metals Elements of the metallic reagent seem essentially responsible for that To be absorption of sulfur oxides in the regeneration zone. Accordingly it is advantageous, advantageous, a metal element or elements of a metal Reagent in the catalytic cracking process cycle in the form of the oxide or oxides bring in. However, for the practice according to the invention, one or more of them are useful the appropriate metallic selected for use as the metallic reagent Bring Elemenge into the process cycle. The metallic element or the metallic elements of the metallic reagent are used to absorb sulfur oxides activated in the regeneration zone by the process steps according to the invention. It is believed that the activation either partially or essentially complete conversion of the metal or metals of the metallic reagent into the corresponding oxide or oxides leads. This activation essentially depends does not depend on the exact way in which the metallic element or elements are chemically are combined or bound when they are introduced into the process cycle.

The metallic reagent lies in the regeneration zone in an average Amount sufficient to absorb a major part of the sulfur oxides that generated by burning the sulfur-containing carbonaceous deposits will.

There will be at least 50% and advantageously more than about 80% of the such burning generated sulfur oxides by the metallic reagent absorbed in the regeneration zone. As a result, the concentration is the sulfur oxides in the exhaust gases of the regeneration zone according to the new invention Process less than about 600 to 1000 parts by volume each million (ppmv), advantageously less than about 600 ppmv, and more preferably less than about 400 ppmv.

The amount of metallic reagent used, calculated as metal or metals, is preferably in the range of about 25 parts per million to about 7% by weight, particularly preferably in the range from about 0.01% by weight to about 5% by weight and most preferably in the range of from about 0.1% to about 0.5% by weight of the solid particles.

Certain individual solids among the solid particles of the invention Procedures may contain a quantity of metallic reagent that is above average Amount thereof is in the solid particles, provided that such individual Solids are mixed with other individual constituents of the solid particles, which contain a smaller amount of the metallic reagent, so that the solid particles the above contain average values of metallic reagent.

The stripped deactivated catalyst is at regeneration temperatures is generated in the region where a stable metal and sulfur Compound in the solid particles of the metal in the metallic reagent and the sulfur oxide is formed. The regeneration temperatures are preferably in the range of about 566 to about 788 ° C (about 1050 to about 14500F) and particularly preferably in the range of about 638 to about 73200 (about 1180 to about 1350 ° F). the Hydrocarbon feed is cracked at reaction temperatures in the range in which the metal and sulfur containing compound in the solid particles among Formation of a sulfide of the metal in the metallic reagent reacts. The cracking temperature is preferably in the range of about 454 to about 6490C (about 850 to about 12000F) and most preferably in the range of about 466 to about 5930C (about 870 to about 11000F). The strippable debris are deactivated by the Cracking catalyst with a vapor containing gas and at stripping temperatures in stripped of the area where the sulfide of the metal in the metallic reagent reacts with water to form hydrogen sulfide gas. The stripping temperatures are preferably in the range of about 554 to about 649 0C (about 850 to 1200 ° F) and most preferably in the range of about 466 to about 5380 (about 870 to about 10000F). The weight ratio of steam to molecular sieve type cracking catalyst, which is introduced into the stripping zone is preferably in the range of about 0.0005 up to about 0.025 and more preferably in the range from about 0.0015 to about 0.0125. The reaction zone exhaust gases preferably contain at least 0.01% by volume and especially preferably at least 0.5% by volume of oxygen in order to achieve the desired reduction in harmful substances To achieve gases in the emissates.

According to one embodiment of the invention, this is a metal in the metallic reagent-containing material is soluble or dispersible in oil or water Compound and the metallic reagent is used in the cracking catalyst of the molecular sieve type incorporated. In such a case, the metallic reagent is either in the crystalline aluminosilicate or the molecular sieve type cracking catalyst matrix incorporated.

In this embodiment of the invention, the solid particles additionally at least one component selected from the solids, which are essentially are inert to the cracking of the hydrocarbon feed and an amorphous one Cracking catalyst include; and the metallic reagent becomes such a component incorporated. In this embodiment, the compound is included in the process cycle catalytic cracking, the cracking reaction zone, the stripping zone and the regeneration zone comprises, preferably a metal salt. Examples include Metal diketonates and metal carboxylates having 1 to 20 carbon atoms. One special preferred such compound is magnesium acetylacetonate.

According to a further embodiment of the invention, the material is containing a metal in the metallic reagent, the metallic reagent in powder form - for example magnesium oxide. In a further embodiment such is Material a composition of the metallic reagent carried by either an amorphous cracking catalyst or a solid that is substantially opposite the cracking reaction is inert.

The invention relates to an improved catalytic cracking process in fluid or fluidized phase, which is an improved method for regeneration of the catalyst used in the fluid catalytic conversion and an improved one Process for reducing the sulfur oxide content of the exhaust gases from regeneration zones for cracking catalysts, which involves the conversion of sulfur-containing hydrocarbon feeds, in which the cracking catalyst is deposited by deposition of sulfur-containing coke the surface of the orrackl catalyst is deactivated.

The solid particles of the process according to the invention, the cracking catalysts of the molecular sieve type are in well-dispersed physical association circulates with each other through the cycle of the cracking process, which defines the cracking zone, comprises the stripper zone and the regeneration zone. The conditions applied cause the reduction of sulfur oxides in the exhaust gases of the regeneration zone.

The cracking catalyst and the metallic reagent according to the invention Procedures serve various and essential functions. The cracking catalyst serves to catalyze the cracking reaction, whereas the metallic reagent essentially is inert to the orracking reaction and, if at all, has a slight adverse effect Effect on the catalytic conversion reaction under the conditions used having.

As for the reduction of sulfur oxides in the exhaust gases from the regeneration zone is concerned, the solid particles absorb sulfur oxides in the regeneration zone. The molecular sieve type cracking catalyst often serves as an adsorbent for itself oxides. The metallic reagent reacts with the adsorbed sulfur oxides Formation of a compound containing metal and sulfur, in particular metal sulfates, and particularly alkaline earth metal sulfates, in the solid particles. Provided, that such a metal and sulfur containing compound under the operating conditions is stable in the regeneration zone, it would be on the surfaces of the solid particles carried to the reaction zone and stripping zone, where it is reduced and considered sulfur-containing Gas, in particular as hydrogen sulfide, is separated.

It is understood that the activity to reduce the emission of sulfur oxides in the exhaust gases of the regeneration zone from metal to metal within varies in the classes that can serve as the metal in the metallic reagent. In the same way, many of the special metals result in the metal in the metallic Reagent may serve, not necessarily equivalent results when compared with other special metals used in the metallic reagent can or when used under varying conditions.

The solid particles of the process according to the invention are finely divided and iron, for example, has an average particle size in the range of about 20 microns or below to about 150 microns so that they are in one place for fluidization respectively. Fluidization in a suitable form. Suitable matrices for the orack catalyst include silica and / or containing alumina. Other refractory metal oxides can be used solely by their ability to regenerate effectively limited under selected conditions. Admixtures of clay-stretched Aluminum oxides can also be used. Preferred catalysts include Combinations of silica and alumina mixed with 'molecular sieves', which are also known as zeolites or crystalline aluminosilicates. Suitable cracking catalysts contain a sufficient amount of crystalline aluminosilicate to maintain the cracking activity of the catalytic converter materially, which can only be achieved through its ability to increase effective regeneration is limited under counted conditions. The crystalline Aluminosilicates usually have a silica to alumina molar ratio of at least about 2: 1, for example about 2 to 12: 1, preferably about 4 to about 6: 1. Cracking catalysts based on silica with a major proportion of silica, for example from about 55 to about 90 wt. silica and about 10 to about 65 weight percent alumina is suitable. Such catalysts can by any suitable procedure such as milling, co-gelation and the like be produced, the only requirement being that the completed The catalyst is in a physical form suitable for fluidization.

Suitable molecular sieves include both naturally occurring and also synthetic aluminosilicate materials such as faujasite, chabazite, aluminosilicate materials of the X- and Y-type and ultra-stable, large-pore, crystalline aluminosilicate materials.

When mixed with, for example, silica-alumina under Formation of a petroleum orracking catalyst lies in the molecular sieve content of the freshly finished Catalyst particles suitably in the range of about 0.5 to about 50 wt. preferred at about 5 to about 50. A high equilibrium molecular sieve cracking catalyst may contain as little as about 1 wt. crystalline material. The ~ crystalline Aluminosilicates are usually available or are in the sodium form Form made, the sodium component is then usually reduced to such a low Amount reduced as possible, usually below about 0.30 wt%, as by ion exchange with hydrogen ions, hydrogen precursors such as ammonium ions or polyvalent ones Metal ions including calcium, strontium, barium and the rare metals Earths such as cerium, lanthanum, neodymium and naturally occurring rare earth metals and their mixtures. The crystalline materials that can be used can be yours Pore structure under high temperature conditions of catalyst production, hydrocarbon processing and catalyst regeneration. The crystalline aluminosilicates have often a uniform pore structure of extremely small size, the diameter the cross section of the pores in the range from about 6 to about 20 angstroms, preferably from about 10 to about 15 angstroms.

The catalytic cracking of heavy mineral oil fractions represents one of the main refining operations involved in converting crude oils to desired Fuels, such as gasoline or gasoline fuels with a high octane number, which are suitable for internal combustion engines with spark ignition are used. A An example of a fluid catalytic conversion process is the fluid catalytic conversion process Cracking process or the catalytic cracking process in fluid or fluidized Phase in which high molecular weight hydrocarbon liquids or vapors with hot, finely divided, solid catalyst particles either in a Sluidbett-or.

Fluidized bed reactor or in an extended riser reactor in Are brought into contact and the mixture of catalyst and hydrocarbon elevated temperature in a fluidized or dispersed State is maintained for a time sufficient to achieve the desired degree of orack to yield higher molecular weight hydrocarbons, typically are present in motor gasoline and distillate fuels.

Suitable hydrocarbon feeds for the cracking process are boiling generally above the boiling range of gasoline or

Gasoline, for example in the range of about 204 to about 6490C (about 400 to about 12000F) and are generally used at temperatures in the range of about 454 to about 64900 (about 850 to about 12000F) cracked. Such charges comprise various mineral oil fractions that are stored above the gasoline or

Gasoline range, such as light gas oils, heavy gas oils, coarse cut oils, Vacuum gas oils, kerosene, decanted oils, residue fractions, reduced Crude oils and petroleum oils or circulating oils derived from any of the foregoing can be derived, as well as suitable fractions, which differ from shale oils, processing derived from tar sands, synthetic oils, coal liquefaction and the like. Such fractions can either be used alone or in any desired combination be used.

The process according to the invention can be carried out in any conventional catalytic Cracking scheme applied, however, is advantageous in a fluid catalytic Orack system or catalytic fluidized bed crack system used where at least a significant portion of the hydrocarbon conversion in a dilute phase Transmission line or a riser reactor system is effected, being highly active Catalysts with relatively high throughput speeds can be used. Preferably the cracking takes place essentially exclusively in the riser reactor and a subsequent one dense catalyst bed is not used for the curing. In a typical Trap using riser reactor cracking to convert a gas oil the throughput ratio or the volume ratio of total charge freshen up Charge can vary from about 1 to 3.

The level of conversion can vary from about 40 to about 100 weight percent and is preferably above about 60% by weight, for example at about 60 to 90% by weight, held. Conversion is the percentage reduction in weight of hydrocarbons boiling above about 22100 (430 ° F) at atmospheric pressure Formation of lighter materials or of coke.

The weight ratio of total cracking catalyst to oil in the riser reactor can vary in the range of about 2 to about 20 so that the fluidized Dispersion has a density in the range from about 0.454 to about 9.07 kg / 0.0283 m3 (about 1 to about 20 lb cubic foot). The catalyst-oil ratio becomes advantageous in the range of about 3 to about 20, preferably 3 to about 7, held. The fluidization or fluidization speed in the riser reactor can be from about 3.048 m to about 30.48 m (about 10 to about 100 feet) per second.

The riser reactor generally has a ratio of length to average diameter of about 25. To make a typical Naphtha product advertises the mixing temperature in the bottom section of the riser reactor preferably at about 538 to about 5430C (about 1000 to about 11000F) to vaporize the oil feed and held at about 51,000 (about 9500F) in the upper exit section.

J? Iir orrack residues and synthetic ire gels are essential higher temperatures required, under these conditions including the requirement a quick separation of the used catalyst from the outflowing oil vapor a very short contact time between the catalyst and 01 is used.

The contact time in the riser reactor is generally around 1 to about 15 seconds, and preferably about 3 to about 10 seconds. Preferred will be short contact times as most of the hydrocarbon cracking occurs during the first part of the contact time occurs and undesirable secondary reactions be avoided. This is particularly important if higher product yields and Selectivities and a lower coke production are to be achieved.

A short contact time between the catalyst particles and the oil vapors can be accomplished in several ways. For example, the catalyst at one or more points along the length of a lower section or the Bottom section of the riser reactor are injected. In the same way, the Oil feed at all points along the length of the lower section of the riser reactor be injected and there can be different injection points for fresh streams and recycle feed streams are counted. The lower section of the riser reactor can for this purpose comprise up to 80% of the total length of the riser reactor to effect an extremely short contact time, which results in an optimal conversion of the petroleum feed causes. If a dense catalyst bed is used, precautions can also be taken for injecting catalyst particles and / or the oil feed directly into the Dense bed zone are taken.

The above conditions are applicable to the production of gasoline or gasoline as fuel for internal combustion engines with spark ignition, however, the process can also aim at maximum production of heavier hydrocarbon products such as jet fuel, diesel oil, heating oil and chemicals, especially olefins and aromatics.

In the catalytic process, a certain amount becomes non-volatile carbonaceous material or "coke" on the catalyst particles deposited. This "coke" comprises highly condensed aromatic hydrocarbons, which generally have a lesser amount of hydrogen, for example about 4 to about 10% by weight. If the hydrocarbon feed contains organic sulfur compounds, so-the "coke" also contains sulfur. With the increasing coke deposit on the catalyst reduces the activity of the catalyst for cooling and the selectivity of the catalyst for the production of gasoline mixtures. The catalyst particles can retain a large part of their original properties by removing the main part recover the coke in a suitable regeneration process.

The catalyst consumed in the petroleum conversion reactor is used stripped or stripped at the entrance to the regenerator.

The stripper vessel, which is in a fluidized bed catalyst cracking unit is used, can conveniently essentially at the transition temperature of the Reactor in the range of about 454 to about 6490G (about 850 to about 1200 ° F) and is preferably maintained above about 46600 (about 870 ° S). The preferred one Stripper gas is steam, although steam containing nitrogen or other steam containing inert gas or exhaust gas or flue gas can also be used. The stripper gas is activated at a pressure of generally about 0.70 (about 10 psig), and preferably about 2.46 atmospheres (about 35 psig), resulting in an im substantial complete removal of the volatile compounds from the consumed Conversion catalyst is suitable.

The process of the invention can be used within any conventional cracking catalyst regeneration process respectively. . - systems are used, but will be beneficial in a regeneration system used, the at least one sealing bed and at least one dilution phase zone includes. The stripped spent catalyst parts can be found in the section with the dense bed of the regenerator vessel through suitable lines from the stripping vessel come in here. Entry can be from the floor or from the side, preferably near the top of the dense bed fluidized zone. Entry can also be done from the top of the regenerator, where the catalyst initially with substantially spent regenerator gas in a limited dilute phase Zone was brought into contact.

The catalyst is regenerated by burning off the coke deposits from the catalyst surface with a gas containing molecular oxygen, like air. Many regeneration techniques are carried out commercially, where a considerable regeneration of the catalyst activity depending on to the Extent of coke removal is achieved. With the progressive removal of the coke the removal of the remaining coke from the catalyst becomes more and more difficult and in practice, an intermediate stage of the re-established is used as an economic compromise Accepted catalyst activity.

Burning off the coke deposits from the catalyst requires a large volume of oxygen or JluSt. In a simplified way, coke oxidation can be viewed as the oxidation of carbon and can be represented by the following chemical equations, but this is not intended to be a limitation: Reactions a) and b) both proceed under typical catalyst regeneration conditions where the catalyst temperature can range from about 566 to about 7880C (about 1050 to about 1450 ° Z) and are examples of the gas-pollutant chemical interactions that occur when the catalyst is regenerated at temperatures within this range. The effect of increasing the temperature is reflected in an increased rate of combustion of the carbon and a more complete separation of the carbon or coke from the catalyst particles. Since the increased combustion rate is accompanied by an increased release of heat, the gas phase reaction c) can take place if sufficient free or molecularly oxygen is present. This latter reaction is set in motion and carried on by free radicals and can be catalyzed.

The burning off of the sulfur-containing coke deposits from the catalyst also leads to the formation of Sch.1efeloxiden, which can be represented by the following chemical equations, which are not intended to be limiting: Reactions d) and e) also occur under typical regeneration conditions for cracking catalysts. While reaction d) proceeds rapidly, reaction e) proceeds relatively slowly. Reaction e) can be catalyzed by any catalyst which catalyzes reaction c) above.

lMolecular sieves adsorb sulfur oxides and therefore the reaction can take place e) on the cracking catalyst in the solid particles of the procedure according to the invention take place. Other constituents of the solid particles can also be sulfur oxides adsorb. The resulting sulfur trioxide can then be mixed with a suitable metal or particularly a metal oxide in the metallic reagent react to form of a stable metal sulfate in the solid particles. Become the solid particles separated from the exhaust gases of the regeneration zone, the metal sulfate is in the solid particles returned to the reaction zone. So the sulfur cannot- in Form of gaseous sulfur oxides in the exhaust gases of the regeneration zone.

The sulfate remains on the solid particles when they go to the cracking zone arrive, and is in the existing reducing atmosphere in the sulfide of the metal in the metallic reagent and possibly in hydrogen sulfide converted.

When stripping with a stripping gas containing steam in the stripping zone the sulfur is converted into hydrogen sulfide and enters the effluents of the Wiper zone off.

The metallic reagent is regenerated and renewed in this way for the reaction with sulfur oxides on the next passage through the regeneration zone made suitable. Hydrogen sulphide can then be added to the cracked products obtained from the stripper zone, separated and in the usual way in elementary Sulfur can be converted.

These reactions can be summarized by the following equations, which, however, are not intended to represent a restriction: Regenerator Reactor Stripper These reactions are made possible by the molecular sieve type cracking catalyst and the metallic reagent according to the method of the present invention. The high cracking activity normally present in the molecular sieve type catalyst is essentially unaffected by the presence of the metallic reagent so that the expected feed conversion and yield of cracked products are achieved along with reduced emissions of carbon monoxide and sulfur oxides.

The metallic reagent can be in finely divided form like a powder, separately from the molecular sieve type cracking catalyst or any other support are present. In such a case, the metallic reagent is a powder that is introduced separately into the cycle of the catalytic cracking process and with the molecular sieve type cracking catalyst in situ in the cycle of the catalytic Cracking process is mixed, but not before the molecular sieve-type cracking catalyst is introduced into the cycle of the cracking process. In general it is one of these Powdered metallic reagent is advantageous because the powder is easy to load and to be handled in a fluidized catalytic cracking process system is. The particle size of the powder should be chosen so that segregation or separation of the particles at the fluidization velocities is avoided. It is beneficial if the particles in such a powder are not so tiny, that problems like excessive emission with the gases from bed being dragged along particulate Material occur. However, filters, cyclones, precipitators or separators are used and the like usually in connection with the operations of the fluidized catalytic cracking used to remove most of the entrained particulate Recover material and return it to the loss reduction system. The powder should be sufficiently firm to prevent excessive abrasion and a Decomposition of the classified powder can be avoided. Often the middle one is Particle size of the powdered metallic reagent each at about 0.5 or 1 to 100 microns, preferably less than about 50 microns in diameter. It was determined, that particles are micro-sized, i.e. with an average particle size of less than about 1 micron, for example about 0.01-0.5 micron, to form aggregates with a larger size can tend to favor the process according to the invention can be used. Examples of powdered metallic reagents that Can be used according to the invention are magnesium oxide and calcium oxide, dolomite and Trimex manufactured by Trimex Corporation and described in U.S. Patent 3,630,696.

Alternatively, the metallic reagent can be on a suitable carrier, which differs from the molecular sieve type cracking catalyst, outside the Cracking process cycle will be applied and the composite material will then introduced into the cracking process cycle, where it becomes part of the solid Particle will. Such a support can be an amorphous cracking catalyst or a Be solid which is and can be substantially inert to the cracking reaction be ceramic in nature, for example. In such a case it will be on a Supported metallic reagent then with the cracking catalyst from Molecular sieve type mixed within the cracking process cycle, but not before introducing the molecular sieve-type cracking catalyst into the cracking process cycle became. It is beneficial to use a porous support, which is often a surface including the area of the pores on the surface of at least about 10, preferably at least about 50 m 2 / g. Examples of these carriers are silica, alumina, silica-alumina, and the like. The metallic reagent can be ion-exchanged, impregnated into such a substrate or other means - by contacting the substrate or a component thereof with a solution or solutions of a compound or compounds of the metal in the metallic reagent in an appropriate amount necessary to create the desired Concentration of the metallic reagent within the scope of the present invention is required. The metallic reagent can with such Substrate either at any stage during the manufacture of the substrate or can be combined after the substrate is manufactured. A method of familiarization consists in an ion exchange of the substrate.

The ion exchange of silica-containing resp.

silicon containing substances or clays with a solution or solutions a compound or compounds of the metallic element or elements of the metallic reagent. Suitable compounds for this purpose include the metal halides, preferably chlorides, nitrates, amine halides, oxides, sulfates, phosphates and others water soluble inorganic salts; as well as the metal carboxylates with 1 to 5 Carbon atoms and the alcoholates.

Alternatively, the metallic reagent can be incorporated into the cracking catalyst from Molecular sieve type or a part thereof, in the solid particles of the invention Procedure to be introduced into the catalytic cracking process cycle, but not before the molecular sieve-type cracking catalyst enters the process cycle the cracking process is introduced. In such a case, the metallic Reagent is introduced into the cracking catalyst during the cracking process cycle. In In such a case, the method of introduction should be carefully chosen so that the cracking activity and the selectivity of the cracking catalyst do not be adversely affected.

In all of the foregoing cases, the exact manner in which- is the metal or the metals of the metallic reagent in the molecular sieve type cracking catalyst, introduced the amorphous cracking catalyst or the substantially inert substrate are not known with absolute certainty. The metals occur in a complex Combination with the carrier material and other components of the solid particles according to of the invention. It should therefore be understood that the use of the terms "metallic Reagent "and introduced or incorporated" into the substrate, the metals as components, which are on the carrier material in combined or bound form and / or in elementary state.

The impregnation can be done in any way that the structure of the substrate is not destroyed. The metallic reagent can act on the cracking catalyst of the molecular sieve type only within the cracking process cycle or in an opposite one hydrocarbon cracking inert support or amorphous cracking catalyst either be impregnated inside or outside the cracking process cycle. The impregnation differs from cation exchange. The impregnation leads to a larger one Deposition and a primarily physical association on the surface of the substrate, whereas the ion exchange to a primarily chemical association and a larger one Diffusion and therefore leads to less deposition on the surface. at After impregnation, the metal is deposited and there is no significant ion exchange between the metal and the substrate. When impregnating a substrate you can the metal or metals in the metallic reagent in or as a water soluble or compound soluble or dispersible in an organic solvent or compounds are present in an amount or in amounts sufficient to that the desired amount of metal or metals is contained on the substrate and the substrate is brought into contact therewith. The composite material can dried to remove the solvent, where the metallic reagent remains deposited on the substrate.

Water-soluble nitrate salts are preferably used in the impregnation solution used as the residue from the thermal decomposition of the nitrate salts with regard to relatively harmless to the activity of the cracking catalyst for the hydrocarbons is. The halogen and sulfate salts of the metal to be impregnated can also be used. However, since by-products involved in the thermal decomposition of this Salts are formed, detrimental to the effectiveness of the hydrocarbon cracking catalyst These salts are most commonly used when the metallic reagent is deposited on substrates which are essentially inert to the cracking reaction and which do not materially adversely affect the hydrocarbon cracking reaction.

Another method of physical deposition of the metallic Reagent on a substrate; especially on porous substrates such as crystalline Aluminosilicates, is the adsorption of a fluid of a decomposable compound or of decomposable compounds of the metal or metals in the metallic Reagent on the substrate, causing thermal or chemical decomposition of the compound or the connections are made. The substrate can be activated by heating, to remove any adsorbed water, followed by contact with a decomposing one fluid compound or compounds of the metal or metals in the metallic Reagent is brought into contact with the compound or compounds adsorbed to the substrate. Typical examples of such compounds are metal alkyls, volatile metal halides, and the like. The adsorbed compound or the adsorbed compounds can then be thermally or chemically their active state can be reduced, creating a metallic on the substrate Reagent remains evenly dispersed. The thermal reduction can for example take place in the regeneration vessel during the regeneration process.

However, it is also advantageous to use a compound or compounds of the metal or metals in the metallic reagent in the cycle of the cracking process and insert it into the substrate in situ. Such a connection respectively.

such compounds can be in either 01 or water soluble or dispersible form and in the solid, liquid or gaseous state be introduced at each stage of the cycle of the cracking process, so that one eite Distribution in the solid particles is achieved. For example, such Connection or can such connections either with the charge or the fluidizing gas in the reaction zone, with the regenerator gas, the torbanite (orch oil ") or water in the reaction zone or with the stripper gas in the stripping zone can be mixed or introduced as a separate stream. Suitable In situ introduction compounds include metal salts. Examples include metal diketonates and metal carboxylates having 1 to 20 carbon atoms. A specific example is the magnesium acetylacetonate.

Preferred embodiments of the method according to the invention include the operation in conjunction with the regeneration system of US Pat. No. 3,909,392. US Pat. No. 3,909,392 is intended to be entirely encompassed by the present description. It is directed to the improvement of a catalytic cracking process, including the improved method for catalyst regeneration in the fluid catalytic Conversion of hydrocarbon feeds, with the catalyst by deposition is deactivated by coke on the catalyst surfaces, directed.

This process makes it possible to adjust the coke content to the regenerated Keeping the catalyst at an extremely low level while taking a favorable thermal equilibrium is obtained in the conversion unit and an exhaust gas is formed with an extremely low carbon monoxide content. The warmth of the Combustion of the carbon monoxide is absorbed by the regenerated catalyst and forms part of that required in the hydrocarbon conversion zone Process heat. According to one embodiment of the method of this patent specification the combustion of carbon monoxide to carbon dioxide becomes essentially complete within the regeneration vessel in a relatively dilute secondary catalyst regeneration zone carried out, preferably at a temperature of about 649 to 816 ° C (about 1200 to 1500 ° F), more preferably from about 652 to 78800 (about 1205 to 14500F). The temperature in the secondary zone can be around 28 or 560C (so or 100 ° S) above that of the first regeneration zone.

The partially regenerated catalyst from a relatively dense primary The catalyst regeneration zone can be controlled in a controlled manner by the secondary zone be passed through in a quantity and at a speed sufficient to essentially all of the combustion occurring in the second zone to absorb occurring heat. Although most of the coke from the catalyst is burned in the primary zone, more coke is partially regenerated from the Catalyst burned off during its presence in the secondary zone and it can recovered a catalyst for recycling to the hydrocarbon conversion stage which is essentially free of coke.

According to a second embodiment of the process of U.S. Patent 3,909 392 does essentially all of the combustion, including both oxidation of the coke or carbon on the catalyst as well as the oxidation of the Carbon monoxide within a single, relatively dense phase of the regeneration zone because of the favorable control of mainly the regeneration temperature and the gas velocity.

In the same way, when carrying out the invention Method according to embodiments including the regeneration system of US Pat. No. 3,909,392 the bulk of the carbon monoxide produced by the combustion of the Regeneration zone heat released by the solid particles according to the invention absorbed, which entrap the cracking catalyst, eliminating some of the in the cracking zone required heat is supplied. Such embodiments make it possible in a favorable manner of the process according to the invention results in considerable combustion of coke and carbon monoxide in the dense phase zone, if any, in the comparison with a possibly existing zone with a dilute phase a much larger one Amount of solid particles is present to dissipate the heat generated. With The heat generation increases with the proportion of combustion in the dense phase zone in the thin phase zone is significantly reduced, eliminating the need for a rapid movement of the solid particles into the dilute phase zone for absorption the generated heat is reduced or eliminated.

In such embodiments, the method includes using of the solid particles of the present invention comprising a molecular sieve type cracking catalyst and the metallic reagent of the method according to the invention comprise in a system which essentially brings about the complete combustion of the carbon monoxide. Of the The low coke content achieved in the catalyst is below about 0.2% by weight, preferably below about 0.05 wt%.

This process can lead to exhaust gases with a carbon monoxide content below about 0.2% by volume, for example about 500 to 1000 ppm and as low as about 0 to 500 ppm lead. The process also includes measures or facilities for extraction the heat released by direct transfer to the solid particles within of the regeneration vessel.

In such embodiments, the fluidizing or

blowing up gas in the dense zone of the regenerator at a speed from, for example, about 0.06 to 1.22 m (0.2 to 4 feet) per second, in particular from about 0.15 to 0.91 m (about 0.5 to 5 feet) per second. That for sluidization The regeneration gas used for the dense bed contains free or molecular oxygen and the oxygen is fed into the regenerator preferably in an amount which is slightly above that for the complete combustion of the coke (carbon and hydrogen) is needed in carbon dioxide and steam.

The amount of oxygen in excess of that required for complete separation of the coke required can be from about 0.1 to about 25 or above percent of theoretical stoichiometric oxygen demand for complete combustion of the coke are, however, it is advantageously not more than about 10%. For example, air is used as the regeneration gas used, a 10d0 excess of air only leads to about 2% by volume Oxygen in the spent outflowing gas stream. Concentration is advantageous of molecular or free oxygen and carbon monoxide at any point in the regenerator kept outside the explosive area under the given conditions, preferably the concentration of carbon monoxide is below the explosive range in these Conditions to eliminate the risk of explosion.

The regeneration gas can be used in addition to free or molecular oxygen inert gas or diluent gas such as nitrogen, steam, etc., recycle gas from the regenerator effluent and the like. Often the oxygen concentration is of the regeneration gas at the inlet of the regenerator about 2 to 30 vol, -, preferably about 5 to 25 vol. Since air is purposefully used as a source of oxygen, can a major portion of the inert gas will be nitrogen. The inert gas can be used to To dissipate excess heat from the combustion of the coke from the catalyst. Of the Effluent from the regenerator provides a source of hot inert gas Part of this gas can be returned to the regenerator will, for example in connection with sufficient incoming air or containing oxygen Gas, including essentially pure oxygen, to create the desired Oxygen content. In this way, the recycling gas can be used in direct heat exchange Increasing the temperature of the regenerator gas to create even greater heat utilization used in the system.

Solid particles in the dilute phase can partially enter the separation zone generally cyclone separators in several stages includes, of which solid particles directly through dip lines ("dip-legs") into the Dense bed zone can be returned and used regeneration and combustion gases collected in a chamber and finally for suitable recovery of the therein contained thermal energy can be emptied. The recovery procedures for the heat from the exhaust gases include the steam generation, the stripping of the consumed Catalyst, indirect heat exchange with various refining streams, such as the feed to the special conversion process and the application in various drying or evaporation devices.

The attached drawings, Figures 1 and 2 give elevations, partially in cross-section of embodiments of apparatuses used for catalyst regeneration according to the embodiments of the method according to the invention including the regeneration scheme U.S. Patent 3,909,392 are suitable. Indeed, such embodiments used favorably in many existing petroleum-hydrocarbon cracking processing units werder, especially in catalytic fluid cracking units with a variety of spatial arrangements for the orrack, stripping and regeneration sections.

Figure 1 shows an embodiment of the invention in which the stripped spent catalyst, that from the orrack reactor, not shown enters the regenerator from the bottom. Solid particles that have a metallic reagent impregnated catalyst from a stripping zone in association containing the catalyst, exit the reactor and emerge from the bottom into the regeneration vessel. The solid particles flow through the inlet ducts 2 and 3 upwards and empty through the exit heads 4 and 5 into the dense Bed. The dense phase bed is held in the lower section 6 of the regeneration vessel and extends up to the phase interface 7. Solid particles within the Dense-phase bed are created by the flow of combustion air through the pipe 8, the shut-off device 9 and the line 10 fluidized to form a buffer ring 11 or whirled up. A substantially balanced air flow path through the regeneration zone can by the application of additional air rings that are not are shown, depending on the order.

The combustion of the coke on the spent catalyst initiation with air takes place within the dense-phase bed. Higher temperatures can by temporarily burning a stream of torbanite oil, for example of a decanted oil, can be achieved within the bed. The torbanite oil (torch oil ") can be added through line 12, shut-off device 13 and line 14 earth, which ends in a nozzle lying above the air ring 11. The speed the fluidizing air continuously becomes part of the solid particles upwards led into the dilute phase zone, which is the upper part 15 of the regenerator vessel occupies, i.e. the section above the phase interface 7.

The combustion of the coke continues in the dilute phase Zone and the largely consumed combustion gas is dragged along with solid particles are drawn off in a first stage of oyclone cutters 20 and 21. Most of the solid particles are separated off in the first cyclone stage and emptied through the dip lines 22 and 23 into the dense phase zone. Gases and residue solid particles become the second through cyclone intermediate lines 24 and 25 Cyclonabscheiderstufe 26 and 27 passed, where essentially all of the remaining Solid particles separated and through the dip lines 28 and 29 in the dense phase Down the bed. The substantially consumed combustion gas is then passed through lines 20 and 31 into a chamber 32 and finally drained from the regenerator vessel through line 33. This outflow can be in suitably a heat exchange, not shown, with a refining stream or to generate process steam. Solid particles containing the regenerated catalyst contained from the dense bed are passed through the standpipes ("Standpipes") 34 and 35, which are equipped with Samnlex heads 36 and 37, for Return to the cracking reactor withdrawn.

\ normally! Although the supply of combustion air is in excess of oxygen over the complete combustion of the coke on the catalyst particles The amount of steam and carbon dioxide required can result in combustion of the coke in the dense phase bed according to one embodiment of the invention, which employs the regeneration system of US Pat. No. 3,909,392 does not take place entirely. In this embodiment, the combustion gases from the zone contain ascending the dense bed, a substantial amount of carbon monoxide as well as carbon dioxide and oxygen. The coke and carbon monoxide remaining on the catalyst are essentially completely developed in the thinned-phase zone under great heat burned. If the carbon monoxide burns in the dilute phase, it usually lies a high temperature zone over much of the dilute phase zone in front of and especially at the point that is marked with X and slightly by a window, not shown, can be observed in this horizontal plane. the Control of the regeneration temperature within the dilute phase zone becomes partial by absorption of heat through the mass of solid particles caused, either carried upwards by the ascending flow of combustion gas or from the dense bed through the escape pipe 40 and a solids header 41 escape, from where a fountain of solid particles spreads into the dilute-phase zone distributed. The solid particles can by air, steam or other inert gases that through the device 42, the locking device 43 and the flow tube 44, which is located in the lourzen distance into which extends below the end of the Entlleicherrohres 40, enter, subtracted from. Excessive temperatures in the top of the regenerator can continue by distributing steam, for example through the pipes 45 and 46, the shut-off device 47 and the line 48 to the steam outlet ("steam pod ") 49. Temperatures in the vicinity of the chamber (" plenum ") can be controlled also by steam passing through the line 50, the shut-off device 51 and the line 52 to the steam ring 53, which surrounds the chamber 32, can be controlled. Possibly a further, not shown, cooling can be created by spray water, which is advantageously directed in the area of the cyclone lines 24 and 25. Such lower temperatures favor the formation of stable metal and Sulfur-containing compounds in the regeneration zone.

FIG. 2 shows an example of a further embodiment of the Invention using the regeneration system of U.S. Patent 3,909,392, wherein the solid particles, the stripped spent catalyst and metallic reagent and come from the cracking reactor, introduced into the regenerator from the side will. Solid particles that contain spent catalyst associated with the metallic Reagent is impregnated, enter the regeneration vessel 101, through the line 102, which lies just below the interface phase surface 107, flows downwards in the regeneration vessel to provide an inlet to the dense phase bed that is in the bottom of the Section 106 is kept to allow. The fluidization of the solid particles is effected by combustion air passing through line 108, the shut-off device 109 and the line 110 is directed to the air ring 111. Other rings not shown can optionally for a further equilibrium of the air distribution over the Regeneration zone can be used.

As described for Figure 1, the combustion of the coke from the spent catalyst particles initiated within the dense phase zone where possibly higher temperatures due to temporary burning of a stream of torbanite oil can be achieved in the zone. Such a "torch" oil can pass through the pipe 112, the shut-off device 113 and the line 114, which detects in a nozzle, added will.

The speed of the fluidizing or whirling air can by continuously carrying solid particles upward for heat absorption be controlled in the dilute phase zone, which is in the upper portion 115 of the Regenerator vessel is located, i.e. in the section above the phase interface 107. The combustion of coke as well as the combustion of carbon monoxide can take place in the dilute phase Zone further leads and the largely consumed combustion gas is combined with the entrained portion of the solid particles in a first stage of the cyclone separator 120 and 121 deducted. Most of this solid particle is in the first Separated cyclone stage and through the dip lines 122 and 123 in the downward flow in the dense phase zone is emptied.

Gases and remaining solid particles are then passed through the Oyclone intermediate lines 124 and 125 to the second stage of cyclone separators 126 and 127 where essentially all of the remaining solid particles are separated and downstream through dip lines 128 and 129 into the dense bed be discharged. The essentially consumed combustion gas then passes through the lines 130 and 131 into the chamber or air chamber (t'plellum ") 132 and becomes finally drained from the regenerator vessel through line 133. Solid particles, containing the regenerated catalyst from the dense bed, are through the Standpipes 134 and 135 removed, equipped with collector heads 136 and 137 are and returned to the catalytic gray reactor.

As described for the embodiment of Figure 1, it burns Carbon monoxide in the dilute phase with the formation of a high temperature zone over a large part of the thinned-phase zone and in particular around the area marked X. Location. The control of the regeneration temperature within the dilute phase zone is largely achieved by heat absorption by the mass of solid particles, which are carried along with the ascending flow of combustion gas. temperatures in the vicinity of the chamber, the cyclones and the connecting lines can optionally be reduced by means of steam passing through line 150, the shut-off device 151 and the line 152 is fed to the steam ring 153 which surrounds the chamber 132. Water spray devices not shown can also be used.

According to a further particularly preferred embodiment of the invention becomes the device of Figure 2 with a considerable change in the working parameters used in comparison with the embodiment described above. At this Embodiment are the gas velocity and the inlet of the solid particles adjusted so that a complete combustion of the coke and the substantially Carbon monoxide takes place within the dense phase and the heat is distributed over the bed will.

If the system is operated according to one of the first two mentioned above Embodiments, the recovery takes place through the essentially complete Combustion of coke and carbon monoxide heat released by absorption on solid Particles in both phases and returning the solid particles to the dense phase, thereby also maintaining the stable high temperature in the dense phase zone. is ensured. The returned solid particles can provide additional heat bring with you, which serves to bring the temperature of the dense phase zone to a temperature to raise the incineration of additional increments of coke deposits favored, so that the combustion of the remaining coke deposits essentially completely done. If the system is operated in such a way that essentially the entire Combustion takes place completely within the dense catalyst phase, so will the heat through this phase with the absorption by the fluidized solid particles dispersed and the remaining deposits of coke are burned. Accordingly contain in all embodiments the solid particles, which the regenerated Contain catalyst, which ird returned from the regenerator to the cracking reactor, expedient about 0.01 to about 0.10 wt%, preferably 0.01 to 0.05 wt%, and especially preferably about 0.01 to about 0.03 weight percent carbon or coke on the catalyst and can be applied from the regenerator at an advantageous temperature be removed in the crack reactor.

A major advantage of the invention is the creation of one regenerated catalyst, which generally has improved activity and selectivity characteristics which come closer to those of a fresh conversion catalyst, in particular for use in conversions that require very short contact times in riser reactors be achieved. The cracking activity of the catalysts containing screens and their Selectivity for converting carbon dioxide feeds into desired ones te products are each strengthened in a favorable manner by the distance of residual carbon or coke on the catalyst during regeneration influenced. The low coke content on the regenerated catalyst is special in the case of fluidized bed catalysts, the catalytically active crystalline aluminosilicates are preferred contain. Accordingly, higher yields of the desired conversion products can be achieved can be achieved in cracking processes using a lower dense phase zone and an upper dilute phase zone in the regeneration zone can carry out the oxidation of the carbon monoxide to carbon dioxide up to a major proportion, often at least about 60 and often about 65 to 95 ^, 0 or above in the dense phase of the regenerator can be fully achieved. The oxidation of carbon monoxide to carbon dioxide in the dense phase provides heat to help maintain combustion the coke deposits on the fluidized bed catalyst. In addition, it is due to the oxidation a substantial proportion of the carbon monoxide in the dense phase is less Carbon monoxide content for combustion in the upper phase of the fluidized bed catalyst present in the regenerator, so that an "afterburn" and high temperatures due to uncontrolled excessive carbon monoxide combustion in the upper part of the Regenerators, which have a detrimental effect on the construction of the reactor, ^ the exhaust gas vent, the collectors for particulate materials in the exhaust gas, e.g. Cyclones, and which can also impair the catalyst activity can be reduced or avoided.

Best particles that the regenerated catalyst particles with a contain unusually low residual coke content, are extracted from the dense phase and at substantially the temperature of the dense bed through a standpipe to the Cracking reactor for contact with the fresh carbon / hydrogen feed or the Mixture of these with returned hydrocarbon tracts directed. Because the oxida- tion of carbon monoxide produced by the combustion of the coke deposits has arisen on the catalyst, take place to a major extent in the dense phase can, and according to the preferred embodiments essentially entirely in the dense phase occurs, the regenerated catalyst can be sent to the cracking reactor a much higher temperature, as well as with a higher activity than was previously possible with conventional methods.

A major advantage of the method of the invention is that it is unusual low carbon monoxide content- the exhaust gases from the regenerator that are obtained can. Usually contains the exhaust gas from the usual regeneration of gray catalysts about 6 to 10% carbon monoxide, a similar amount of carbon dioxide, and very little Oxygen, the content of carbon monoxide in the exhaust gas according to the new invention Regeneration process at less than about 0.2 vol., For example at about 500 up to 1000 parts per million, based on the volume (ppmv). Advantageous the content is even lower, for example in the range from 0 to about 500 ppmv. This low concentration allows carbon monoxide in the exhaust gas or flue gas flow the direct release of the exhaust gases into the atmosphere, since they are the same as the air quality standard is equivalent to. If desired, remaining carbon monoxide can be added appropriately be burned in the vent of the regenerator exhaust line. This inventive advantage In addition, it eliminates the investment costs that would otherwise be required for installation carbon monoxide burners and associated turbine-type devices, or other devices for partial recovery of the following Oxidation of the carbon monoxide generated energy would be necessary, while still adhered to the standard for air pollution from carbon monoxide emissions will.

The method according to the invention creates additional advantages.

These advantages address the problem of afterburning and thermal balance. A major problem in practice, especially in fluidized bed catalyst regeneration occurs and should be avoided, is the phenomenon known as "afterburning", for example by Hengstebeck, "Petroleum Processing", McGrav-Hill Book Co., 1959, pages 160 and 175 and described in "Oil and Gas Journal", Volume 53 (No. 3) 1955, pages 93-94. This expression stands for further combustion from carbon monoxide to sole dioxide according to the above reaction c), which is extremely exothermic. The afterburning is used in catalyst regeneration processes strictly avoided as it can lead to very high temperatures Damage to the equipment and permanent deactivation of the cracking catalyst particles being able to lead. With many flow catalyst regeneration measures there is an afterburn takes place and there has been a considerable state of the art to include a number of measures to control the regeneration techniques for the purpose of avoiding afterburning developed. Recently attempts have been made to reduce the regenerator temperatures various reasons, with sophisticated arrangements also being developed with which the regenerator temperatures with the help of suitable devices to control the oxygen supply to the reactor at the point of the beginning Afterburning can be kept, as for example in US-PS 3,161,583, 3,206,393 and 3,513,087. According to conventional practices, at which prevent afterburning is contained in the exhaust gas from the catalytic converter regenerators usually low in oxygen and a significant amount of carbon monoxide and carbon dioxide in almost equimolar amounts.

The further combustion of carbon monoxide to carbon dioxide represents one attractive source of thermal energy, since reaction c) is strongly exothermic. That Afterburn can occur and set at temperatures above about 59500 (11000F) about 2418.6 kcal / kg oxidized. Carbon monoxide (4350 BTU / 1b) free. This typically represents represents about a quarter of the total heat development that occurs during complete Burning coke is released. The burning of carbon monoxide can be in controlled way in a separate carbon monoxide boiler after the separation of the Exhaust gases from the catalyst can be carried out, for example, as in US Pat 2 753 925, with the amount of heat released for different refining operations, such as the generation of high pressure steam is used. Other uses this thermal energy are in US-PS 3,012,962 and 3,137,133 (2 turbine drive) and in U.S. Patent 3,363,993 (petroleum feed preheating). These heat generation processes serve to prevent the release of the carbon monoxide as Prevent component of the exhaust gases into the atmosphere and a potentially serious one Avoid pollution; they require their own elaborated device.

In addition, silica-alumina catalysts are the usually many years in various processes for the extraction of petroleum hydrocarbons used, not particularly sensitive to the content of the remaining Coke on the catalyst, provided that the coke content does not exceed about 0.5 Weight increases. However, silica-alumina catalysts have been widely used displaced by catalysts, which also have a crystalline aluminosilicate component and are known as zeolites or molecular sieves. Containing the molecular sieves Catalysts are and will be much more sensitive to remaining coke strong both in terms of their catalytic activity and catalyst selectivity for converting a charge into the desired product or affects the desired products. Because of the difficulties, the usual Catalyst regeneration techniques - to remove the last remaining carbon deposits the practical coke content usually corresponds to a residual biscuit content on the regenerated catalyst in the range of about 0.2 to about 0.3 weight percent.

Because increased activity and selectivity with cracking catalysts of the molecular sieve type having a low cog content, there is a large one Incentive in the search for means to further reduce the residual coke content. A coke content below about 0.05% by weight is very desirable, but can be achieved commercially by means of feasible facilities are usually not achieved. Considerations regarding larger regeneration vessels, a larger inventory of catalysts, greater heat losses and the like, all are not capable of achieving such ideal equilibrium levels of activity to strive for catalysts.

Many fluid cracking units are based on the principle of arne equilibrium " operated from the burning of coke to the development of the process required heat depends. However, it was not possible through such units take full advantage of cracking catalysts, especially zeolite catalysts exploit, which can be achieved in particular in a riser reactor, where the contact times between the catalytic converters and the oil vapors are extremely small. The type of operation, which leads to a high conversion, along with a high selectivity, what favors a low ratio of catalyst to oil in the riser reactor to less available for heat generation by combustion in the regenerator Amount of coke leads. Accordingly, an external heat source, such as a preheating furnace, can often for charging can be added to the temperature of Alternatively, the unit can be increased at a lower temperature the fresh charge can be operated. Such undesirable features can avoided or reduced to a minimum by the method according to the invention effective extraction of additional heat through the solid particles for transfer to the riser reactor. The usual when burning coke The heat obtained by working methods is approximately 6660 kcal / kg (12000 BTU / lb). By the The method according to the invention makes it possible to obtain those obtainable by burning the coke Raise heat to about 9300 kcal / kg (17000 BDU / lb) or above.

This higher heat of combustion leads to an increase in the regenerator temperature, to reduce the coke content on the regenerated catalyst and to reduce it the circulation rate of the solid particles, with improved yields can be achieved at a given degree of conversion.

Example 1 10 g of a solution of 6.9 g of a lubricating oil additive which 9.2% by weight magnesium, distributed as magnesium hydroxide, magnesium carbonate and magnesium polypropylbenzenesulfonate, dissolved in 33.1 g of a light cycle catalytic oil were in a cracking unit on an experimental scale with a fluidized bed or fluidized bed of 200 g of a commercially available cracking catalyst in equilibrium is cracked, the 2.5 wt .-% molecular sieves and 0.6 wt .-% sodium contained and from a conventional catalytic fluidized bed unit had been withdrawn and then calcined. The cyclizate oil was cracked at 37100 (7000F) for 4 minutes. After rinsing of the catalyst bed with nitrogen for 10 minutes at 6770C (12500F) the catalyst bed cooled to 37100 (700 ° F) and the crack-purge regeneration cycle was repeated until the magnesium, zinc and phosphorus content of the catalyst the level of 1100, 703 or

Reached 59 ppm. The zinc and phosphorus were inherently present.

Example 2 The procedure of Example 1 was repeated, wherein however, the crack-rinse regeneration cycle with 10 g of a 6.5 solution of the oil and 3.5 of a lubricating oil additive containing 1.6% by weight of Zn, 1.3% by weight of P and 4.6 Wt .-% Mg was repeated until the magnesium, zinc and phosphorus content of the catalyst 2400, 1200 or. Reached 1097 ppm.

Example 3 The procedure of Example 2 was repeated, wherein however, a balanced commercial cracking catalyst is used containing 3.3 wt% molecular sieves in a silica-alumina matrix and also withdrawn from a conventional fluid catalytic cracking unit and was calcined and the crack-rinse regeneration cycle was run until the magnesium, zinc and phosphorus content of the catalyst 4600, 340 and 1136, respectively ppm reached.

Examples 4 to 8 A laboratory regeneration unit on a test scale was used to study the effectiveness of a number of impregnated catalysts for the formation of reduced emissions of sulfur dioxide in the exhaust gases of the regeneration zone used. A synthetic exhaust gas or flue gas made from 1500 parts per million sulfur dioxide in a mixture of 4% by volume each of oxygen and water in nitrogen by a fluidized bed of the molecular sieve type cracking catalyst which was impregnated with a metal held in a glass regenerator by an oven to deliver the desired regeneration temperature of 6770C (12500F). The temperature of the catalyst was determined by thermocouples measured. A cyclone was used to separate the entrained catalyst from the Gas emerging from the regenerator is used to make the catalyst in recirculated the catalyst bed. The operating time of the regenerator was a given number of conditions about 40 to about 90 minutes to be sufficient Time to reach the oxidation state of the metal on the catalyst in one to enable an effective system for catalytic fluid cracking.

The sulfur dioxide content of the gas exiting the regenerator was continuously analyzed with an ultraviolet analyzer. the Amount of sulfur dioxide removed from the exhaust gas of the regeneration zone was calculated as Difference between the sulfur dioxide content of the fresh synthetic gas mixture and the gas exiting the regenerator. The volume percent Sulfur dioxide removed from the regeneration zone exhaust gas is a function the time elapsed after the start of the experiment is listed in Table 1. The distant ones Volume percentages were at the time of saturation of the catalyst surface less.

Example 4 represents a comparative experiment in which a flow rate the synthetic exhaust gas mixture of 1084 ml per minute and the unimpregnated, im Equilibrium catalysts of Examples 1 and 2 were used. the Examples 5 and 6 were prepared incorporating that in Examples 1 and 2, respectively impregnated catalyst at flow speeds for the synthetic exhaust gas mixture of 989 and 1014 ml per minute, respectively. Example 7 is a comparative experiment using the unimpregnated catalyst of Example 3 at one flow rate for the synthetic exhaust gas mixture of 891 ml per minute. In Example 8 the impregnated catalyst prepared in Example 3 at one flow rate the synthetic exhaust gas mixture of 992 ml per minute is used. The flow velocities were measured at 1.560C (600F).

Table 1 Example% by volume of sulfur dioxide removed Time 4 5 6 7 8 0-10 78-63 85-82 92-91 36-24 60-49 10-20 65-43 82-78 91-89 24-16 49-39 20-30 43-32 78-74 89-88 16-14 39-33 30-40 32-27 74-70 88-87 14-13 33-30 Examples 9 and 10 In Example 9, the procedure of Examples 4 to 8 was repeated, wherein but a synthetic exhaust gas mixture of 4% by volume of each carbon monoxide and oxygen and water vapor in nitrogen at a rate of about 1000 ml per minute (measured at 15.60C = 600F) by a fluidized bed or fluidized bed a mixture of powdered magnesium oxide with a particle size of 5 microns and finer, and an unimpregnated calcined, in equilibrium commercial cracking catalyst of the molecular sieve type with a content of 5.3 Weight% hydrogen and ion-exchanged rare earths, Y-2yp crystalline aluminosilicate and silica-alumina containing 30 wt% alumina instead of the impregnated catalysts were used. The mixture contained 0.3% by weight Magnesium oxide and about 70% by volume of carbon monoxide were converted into carbon dioxide. In Example 10, the non-impregnated catalyst of Example 9 was used in the absence of magnesium oxide were used under otherwise identical conditions and 58% by volume were used Carbon monoxide converted into carbon dioxide.

Examples 11 and 12 In Example 11, a gas oil feed was used a sulfur content of 1.67% by weight in a commercially available fluid catalytic cracking unit cracked with a riser reactor. Common regeneration gas was used. A molecular sieve type equilibrium cracking catalyst containing from 2.5 Wt% molecular sieves and about 0.6 wt% sodium used. In Example 12, a second gas oil feed was made with a sulfur content of 1.68 wt.% cracked in the same commercial unit, the same Regeneration system and the same cracking catalyst were used, but the Catalyst was additionally impregnated with magnesium and zinc.

The magnesium and the zinc were placed on the catalyst low concentrations of magnesium sulfonate and zinc dialkyldithiophosphate in the form of the lubricating oil additive is deposited in the feed. After a few hours of such a thing In addition, 0.3% by weight of magnesium and 0.1% by weight of zinc were built up on the cracking catalyst. The working conditions and the composition of the exhaust gas of the regeneration zone are listed in Table 2 below.

Table 2 Examples 11 12 Cracking Conditions: Cracking Temperature ° C (° F) 524 521 (974) (970) total feed ratehl / day 5866 5580 (barrel / day) (49200) (46800) Flow ratio 1.07 1.25 Circulation speed of the catalyst kg / min 26.4 23.09 (tons / min) (29.1) (26.4) weight ratio of catalyst to Oil 5.3 5.2 Stripping Conditions: Stripping Temperature 521,518 ° F (970) (965) Steam / Catalyst kg / kg 4.3 4.7 (1bs / tons) (8.6) (9.4) Regeneration Conditions: Dense Bed Temp ° C 688 707 (° F) (1270) (1305) Speed of combustion air kg / hour 187048 221098 (lbsXhrs) 1 (412000) (487000) Composition of the exhaust gas from the regeneration zone CO 2, mole percent 13.0 14.0 CO, mole 0 / o 5.0 5.6 O2, mole percent 0.5 2.0 sulfur dioxide, ppmv 580 60 L e r s e i t e

Claims (21)

Claims 1. A method for reducing the emission of sulfur oxides in the exhaust gases of the regeneration zone of a process for cyclic fluidized catalytic cracking or catalytic cracking in the fluidized phase or fluidized bed phase a hydrogen charge containing organic sulfur compounds, in which i) the feed is fluidized to the cracking in a reaction zone or fluidized solid particles of a cracking catalyst of molecular sieve> yp is subjected, ii) the catalyst particles, which by sulfur-containing carbonaceous Deposits are deactivated, separated from the effluent from the reaction zone and a stripping or stripping zone are fed, in which volatile deposits of the deactivated catalyst by contact with a stripper gas removed, iii) the stripped catalyst particles from separated from the effluent of the stripping or stripping zone and into a regeneration zone are transferred and by burning the non-strippable or strippable sulfur containing carbonaceous deposits from the stripped catalyst particles be regenerated with an oxygen-containing gas and iv) the regenerated Separated catalyst particles from the effluent of the regeneration zone and to the reaction zone are returned, characterized in that a) fluidizable or swirlable Particles containing a metallic reagent to the cracking catalyst during of the catalytic cracking process in the fluid phase or fluidized bed phase, to achieve a mixture of particles that is about 10 to about 99.9975 wt% Cracking catalyst of the molecular sieve type, wherein the metallic reagent consists of at least a free or combined or bound metallic element o consists of the group of magnesium, calcium, strontium and barium, contains and wherein the amount of metallic reagent in the mixture of particles is sufficient, around the absorption of at least about 50% of that during burning of the sulfur-containing carbonaceous deposits in the regeneration zone to effect generated sulfur oxides; b) the feed at a temperature of about 454 to about 649 ° C (about 850 to about 12000J?) cracks, c) the volatile components of the mixture of particles separated from the reaction zone with a stripper gas containing steam at a temperature of about 454 to about 0 Stripping or stripping them at 649 ° C (about 850 to about 1200 ° F) wherein the weight ratio of steam to cracking catalyst is about 0.0005 to about Is 0.025; d) the stripped mixture of particles at a temperature of regenerated about 566 to about 7880C (about 1050 to about 14500F); e) with the mixture of the particles at least about 50% of those in the regeneration zone by incineration the carbonaceous deposits containing sulfur produced sulfur oxides absorbed; f) the mixture of the particles containing the absorbed sulfur oxides transferred from the regeneration zone to the reaction zone; g) an exhaust gas stream the regeneration zone draws off the molecular oxygen and a low concentration contains sulfur oxides; and h) substantially the absorbed sulfur oxides withdraws as a sulfur-containing gas from the reaction and / or stripper zone. 2. The method according to claim 1, characterized in that one is a metallic reagent used, which consists of at least one free or bound metallic element selected from the group of magnesium and galcium. 3. The method according to claim 1, characterized in that the metallic reagent in an amount calculated as metal from about 0.1 to about 0.5% by weight of the particle mixture is used. 4. The method according to claim 1, characterized in that one is a metallic reagent-containing fluidizable particles used, which consists of a consist of metallic reagent located on a carrier, the carrier being selected is selected from the group of amorphous cracking catalysts and solids, which are essentially are inert to the cracking reaction. 5. The method according to claim 4, characterized in that the Carriers from the group of silicon dioxide, aluminum oxide, thorium oxide and thorium dioxide and boron oxides or boron trioxide selects. 6. The method according to claim 1, characterized in that one particles of the molecular sieve-type cracking catalyst used, which is about 90 to about 99.9 % By weight of the mixture of particles. 7. The method according to claim 1, characterized in that one is a The ratio of steam to cracking catalyst used is from about 0.0015 to about 0.0125. 8. The method according to claim 1, characterized in that from the regeneration zone withdraws a gas stream which is at least about 0.01 vol .-% molecular Contains oxygen. 9. The method according to claim 1, characterized in that from the regeneration zone withdraws a gas stream containing less than about 600 ppmv sulfur oxides contains. 10. The method according to claim 1, characterized in that one Feed having a sulfur content in the range of about 0.2 to about 6 weight percent is used. 11. The method according to claim 1, characterized in that as fluidizable particles containing a metallic reagent, particles of magnesium oxide used. 12. Method of reducing the emission of sulfur oxides in the exhaust gases of the regeneration zone of a process for cyclic fluidized catalytic cracking or catalytic cracking in the fluidized phase or fluidized bed phase a hydrocarbon feed containing organic sulfur compounds, in which i) the feed is fluidized to the cracking in a reaction zone or fluidized solid particles of a molecular sieve type cracking catalyst i) the catalyst particles replaced by sulfur-containing carbonaceous Deposits are deactivated, separated from the effluent from the reaction zone and one Wiping or Stripper zone are fed, wherein volatile deposits of the deactivated catalyst by contact with a stripper gas or stripper gas removed, iii) the stripped catalyst particles from separated from the effluent of the stripping or stripping zone and into a regeneration zone be transferred and by burning the non-strippable sulphurous and carbonaceous deposits from the stripped catalyst particles with a Oxygen-containing gas are regenerated and iv) the regenerated catalyst particles separated from the effluent from the regeneration zone and returned to the reaction zone are, characterized in that a) in the catalyst particles at least introduces a metal from the group of magnesium, calcium, strontium and barium, being separated at least one compound of the metal or metals in the Process cycle introduces, wherein the metal is introduced in sufficient quantity is made to ensure the absorption of at least about 50% of that in the regeneration zone Burning of the sulfur-containing carbonaceous deposits produced Effect sulfur oxides; b) the feed at one temperature cracks from about 454 to about 649 ° C (about 850 to about 1200 ° F); c) the volatile Deposits from the deactivated catalyst at a temperature of about 454 to about 649 oO (about 850 to about 12000F) with a stripper gas containing steam, strips, the ratio of steam to cracking catalyst being about Is 0.0005 to about 0.025; d) the stripped deactivated catalyst regenerated at a temperature of about 566 to about 788 ° C (about 1050 to about 1450 ° F); e) with the catalyst particles containing the metal, at least about 50% of the in the regeneration zone by burning the sulfur-containing carbonaceous Deposits formed sulfur oxides are absorbed; f) the catalyst particles that containing absorbed sulfur oxides, from the regeneration zone to the reaction zone convicted; g) withdraws an exhaust gas stream from the regeneration zone, the molecular Contains oxygen and has a low concentration of sulfur oxides, and h) the absorbed sulfur oxides in the form of a sulfur-containing gas the reaction and / or stripper zone essentially withdraws. 13. The method according to claim 12, characterized in that the Selects metal from the group of magnesium and calcium. 14. The method according to claim 12, characterized in that about Introduces 0.1 to about 0.5 weight percent of the metal into the catalyst particles. 15. The method according to claim 12, characterized in that as Metal compound uses a metal salt. 16. The method according to claim 12, characterized in that the Metal compound selects from the group of metal diketonates and metal carboxylates with 1 to 20 carbon atoms. 17. The method according to claim 12, characterized in that as Metal compound magnesium acetylacetonate is used. 18. The method according to claim 12, characterized in that one The ratio of steam to cracking catalyst selects from about 0.0015 to about 0.0125. 19. The method according to claim 12, characterized in that one Regeneration zone waste gas stream containing at least about 0.01 volume percent molecular Withdraws oxygen. 20. The method according to claim 12, characterized in that one Regeneration zone exhaust stream containing less than about 600 ppmv sulfur oxides withdraws. 21. The method according to claim 12, characterized in that one Charge with a sulfur content in the range from about 0.2 to about 6 wt% begins.