PL98590B1 - METHOD OF CATALYTIC CRACKING OF OIL - Google Patents

Description

The subject of the invention is the catalytic cracking of crude oil. In the cracking process with the use of a dust catalyst, higher product yields and higher selectivity are obtained by using a regenerated hydrocarbon conversion catalyst with higher activity and a low level of residual coke, preferably lower from 0.05% by weight with respect to the catalyst, obtained by burning coke from the exhausted catalyst under balanced conditions which substantially support complete combustion of carbon monoxide, provided that the heat evolved by transferring to the catalyst particles, in particular within the dilute zone of the regenerator. Regenerator off-gas can be removed directly into the atmosphere without any appreciable effect on the air quality. Catalytic cracking of heavy crude oil is one of the main refining operations used in crude oil conversion on desired fuel products, such as you sodium-octane gasoline used in internal spark ignition engines. Fluidization catalytic conversion processes are explained by the process of cracking with the use of a dust catalyst, in which, respectively, preheated liquid and gaseous hydrocarbons with a high molecular weight are brought into contact with the hot, sub-theinized solid particles of the catalyst in a reactor with a bed. a fluidized bed or an elongated riser reactor maintained at an elevated temperature in a fluidized or dispersed state for a time sufficient to achieve the desired degree of cracking into hydrocarbons of lower molecular weight, typically found in gasoline and distilled motor fuels. Suitable starting hydrocarbons boil generally at a temperature of 204-649 ° C and usually after scraping the boiling point is 454-566 ° C. In the catalytic process, some non-volatile carbon products or "coke" are deposited on the catalyst particles. They are highly condensed aromatic hydrocarbons, generally containing 4-10% by weight of hydrogen. If coke is formed on the catalyst, the activity of the cracking catalyst and the selectivity of the catalyst in the preparation of the gasoline mixture decrease. The catalyst particles can recover most of them. regeneration of the catalyst is carried out by burning the coke sludge on the surface of the catalyst with an oxygen-containing gas, such as air. There are many methods of regeneration which can be used to obtain considerable recovery of the catalyst activity depending on the degree of removal 98 5903 98 590 4 coke. If the coke is gradually removed from the catalyst, the removal of the remaining coke becomes very difficult and in practice an average recovery of the catalyst is accepted as an economic compromise. The combustion of the coke deposit on the catalyst requires a large volume of oxygen or air. In a simplified manner, we can characterize the oxidation of coke as the oxidation of carbon. This is illustrated by the following chemical equations: a) C +02 CO2 b) 2C +02 2CO c) 2CO + 02 2CO2 Both reactions a) and b) take place under typical catalyst regeneration conditions, at a temperature of 566 ° C -704 ° C and are exemplary gas-solid chemical reaction reactions. The increase in temperature results in an increase in the degree of coal combustion and a greater removal of carbon or coke from the catalyst particles. If the increased degree of combustion is accompanied by an increased development of heat, provided that sufficient oxygen is present, the reaction c) may take place in the gas phase. The latter reactions initiate and develop free radicals. A major problem encountered which has been attempted to be avoided particularly in fluidized bed catalyst regeneration is what is known as "re-combustion" described, for example, in Hengstebeck "Peetoleum Processing" McGraw-Hill. Book Co., 1959, pp. 160 and 175, and in Oil and Gas Journal, Vol. 53 (No. 3), 1955, pp. 93-94. This term relates to the further combustion of CO to CO 2, given above as reaction c Re-combustion must be strictly avoided in the catalyst regeneration process, as it can lead to the formation of very high temperatures, damaging the equipment and permanently disenabling the catalyst particles. of the fluid catalyst, numerous measures have been developed to control the regeneration processes to avoid secondary combustion. When efforts were made to increase the temperature in the reactor for various reasons, By means of suitable means to control the supply of oxygen to the regenerator, for controlling these temperatures at the time the re-combustion begins, such as those described in U.S. Pat. US Am. No. 3,161,583 and No. 3,206,393 and No. 3,513,087. Currently, in practice, in order to avoid re-combustion, exhaust gases from catalyst regenerators contain very little oxygen, and CO and CO2 are present in approximately equimolar amounts. CO to CO 2 is an attractive source of thermal energy due to the high exothermicity of reaction c). Post-combustion takes place at temperatures above about 593 ° C and releases approximately 2414 kcal / kg of oxidized CO. This is about 4 of the total heat released by complete combustion of the coke. Combustion of CO can be carried out in a controlled manner in a separate zone or in a CO boiler after the exhaust gas has been separated from the catalyst, according to the method described in US Pat. US Am. No. 2,753,925, with the release of the thermal energy used in various refining operations such as the production of high pressure steam. Other uses of such thermal energy are described in US Pat. US Am. No. 3,012,962 and No. 3,137,133 (turbine drive) and U.S. US Am. No. 3 363 993 (pre-heating of the crude oil feed). Such heat recovery processes require a separate device, but are designed to minimize the release of CO into the atmosphere as a component of the exhaust gases, avoiding the risk of potentially severe contamination of the atmosphere. Silica-alumina catalysts have been conventionally used for many years. in various cracking processes, petroleum hydrocarbons are not particularly sensitive to the level of coke remaining on the catalyst, provided that the level of coke is not greater than about 0.5% by weight. However, silica-alumina catalysts are increasingly displaced by catalysts that additionally contain a crystalline aluminosilicate constituent, known as zeolite or molecular sieve. Molecular sieve catalysts are much more sensitive to the level of deposited coke, which influences significantly the activity of the catalyst and its selectivity in converting the starting material to the desired product or products. Due to the difficulties encountered in conventional catalyst regeneration methods, as mentioned above, in order to remove the residual carbon build-up, practically the level of coke corresponds to a residual coke content on the regenerated catalyst of about 0.2-0.3% by weight. With the aid of cracking catalysts of the type Increased activity and selectivity of molecular sieves is achievable at low coke levels as a stimulus to the measures being developed to reduce residual coke levels. Coke levels of less than 0.05% by weight are highly desirable, but are usually not achievable by practically economical means. The need for things such as increased regenerators and increased investment in catalyst associated with greater heat losses, etc., will discourage the achievement of an ideal balance of levels of catalytic activity. As already mentioned, the invention relates to a dust catalyst cracking process including catalyst regeneration. used in the conversion of crude oil in the presence of a dust catalyst, which is deactivated by deposition of coke on its surface. The method according to the invention regenerates conversion catalysts, in particular dust catalysts, for a long operating period, helping to maintain the coke layer on its surface. regenerated catalyst at an extremely low level while maintaining a favorable thermal equilibrium in the conversion unit, with an extremely low content of carbon monoxide in the exhaust gas. 40 45 50 55 605 98 590 6 In a preferred embodiment of the invention, the combustion of carbon monoxide to carbon dioxide is carried out substantially entirely in the regenerator in the subsequent relatively dilute secondary catalyst regeneration zone, preferably at a temperature of about 649-816. ° C, preferably around 677—788 ° C. The partially regenerated catalyst, from the relatively dense primary catalyst regeneration zone, flows in a controlled manner through the secondary zone in an amount and at a rate sufficient to absorb substantially all of the heat released by combustion occurring in the secondary zone. Although most of the catalyst coke is burned in the primary zone, the remaining coke, if still present, is burned on the partially regenerated catalyst in the secondary zone and the substantially coke free recovered catalyst can be returned to the hydrocarbon conversion zone. The heat of combustion of carbon monoxide absorbed by the regenerated catalyst provides some of the heat required in the conversion zone. Moreover, the liberated flue gas from the secondary regeneration zone is substantially free of carbon monoxide. According to another embodiment of the invention, substantially all combustion, including both coke or carbon oxidation and carbon monoxide oxidation, takes place in one relatively dense phase of the regeneration zone by appropriate temperature control. Regeneration cycles and gas velocity. The distinguishing advantage of the invention is that it is possible to obtain a regenerated catalyst having an overall increased activity and selectivity closely related to the properties of a fresh conversion catalyst particularly suitable for the conversion achieved in a very short contact time in ascending reactors. May. Accordingly, higher product feed conversion and higher yields of the desired conversion products are achieved. The controlled heat protection provides an efficient heat reservoir, without requiring a large amount of catalyst over the oil in the fluidization conversion zone or the retention of a large amount of catalyst in the regenerator. Carbon monoxide content in the exhaust gas from the regeneration process can be maintained at a level of less than about 0.2% by volume, such as about 5-1000 ppm, and even less, such as 0-500 ppm. This low concentration of carbon monoxide in the exhaust gas allows it to be discharged into the atmosphere while meeting quality standards. An additional advantage of the invention is the elimination of the costs associated with the installation of CO boilers and associated turbine devices or other means required for partial energy recovery. The method of regeneration according to the invention is preferably used in practice as the primary stage in the cracking process. with the use of a dust catalyst in which at least a substantial part of the conversion is achieved in the dilute phase of the feed or reactor system, requiring the use of a very active catalyst and relatively high volumetric velocities. The catalyst regenerated according to the invention is less than 0 0.05% by weight of coke, preferably no more than 0.01% by weight. This remarkably low level of coke is particularly advantageous when a fluidized cracking catalyst containing crystalline aluminosilicates, known as zeolites or molecular sieves, is used. The cracking activity of the catalysts containing molecular sieves and their selectivity in converting the starting products to the desired products is a result of the effect of the increased removal of residual carbon or coke during regeneration. 1 and 2 in the drawing show a partially sectioned elevation view of an embodiment of a catalyst regeneration device according to the invention. The diagram in FIG. 3 illustrates the beneficial effects of conversion and efficiency achieved by reducing the carbon or coke content in the regenerated fluidized bed catalyst. cracking with respect to the generally low values obtained previously. The present invention thus provides a regenerated conversion catalyst having a very low coke content, preferably less than 0.05% by weight, most preferably 0.01-0.03% by weight. by controlling substantially complete combustion of coke and substantially complete combustion of carbon monoxide in the presence of the catalyst particles, while increasing the recovery of the heat released for combustion by heating the catalyst particles and permeating the mass of heated catalyst particles for conversion. The process uses an extremely high and maintained regeneration temperature, which requires careful and balanced control in order to maintain a temperature sufficiently high for a substantially complete combustion of the carbon monoxide while avoiding such a high temperature. temperature such that it would thermally deactivate the catalyst particles or render the regenerator unsafe or incapable of the process. The temperature is preferably about 649-816 ° C, desirable about 677-788 ° C, although sometimes in the lower parts of the regenerator have a satisfactory temperature of even about 621 ° C. The invention is particularly useful in the conversion of crude oil in the presence of a dust catalyst and is preferably used when at least a substantial part of the conversion takes place in the diluted phase feed line or vertical reactor system. . The invention makes it possible to increase the degree of energy conservation in the crude oil batch conversion process, separate the catalyst from the conversion products, regenerate the separated catalyst, recycle the regenerated catalyst to the reactor for the conversion of additional gray starting materials, the increased amount of thermal energy being used in the bend. on a cyclic day by continuously transferring heat from the exothermic to the endothermic process zone. In practice, a particularly convenient method of conversion in the presence of a dust catalyst according to the invention includes cracking in the presence of a catalyst 40 45 50 55 6096 590 7 8 gas oils crude oil and heavy crude oil. For hydrocarbons suitable as components for fuel mixtures for automotive engines, jet engines, domestic and industrial furnaces and the like. The method of the invention consists in the steam-stripped, deactivated petroleum conversion catalyst such as a catalyst with fluoride Hydrocarbon cracking, deactivated by the deposition of carbonaceous substances or coke thereon, is brought into contact with an oxygen-containing regeneration gas in a regenerator adapted to the countercurrent flow of the catalyst and the regeneration gas. Substantially complete regeneration of the catalyst particles by burning the carbonaceous or coke deposits may occur in one relatively dense bed together with the combustion of substantially all CO to CO 2 present. More often, primary regeneration of the catalyst particles occurs in one or more relatively dense fluidized zones. catalyst, located in the first or initial regeneration zone located in the bottom part of the regenerator. Combustion is accomplished by feeding into the dense zone or zones of regeneration gas, at the combustion temperature going upwards, in an amount at least such that the amount of oxygen corresponds to the stoichiometric amount needed to completely oxidize the carbon monoxide formed during the oxidation of coke. The partially exhausted regeneration gas leaving the lower part of the reactor, consisting of carbon monoxide, carbon dioxide and oxygen, contains suspended or entrained particles of at least partially regenerated catalyst. The partially exhausted regeneration gas passes from the dense bed zone to the relatively dilute zone. phase dispersed and suspended in a second regeneration zone, wherein combustion of the carbon monoxide is substantially completed at a temperature suitably maintained at around 677 ° C, preferably above around 704 ° C, by suitable regulating agents, such as so that the temperature in the second regeneration zone does not exceed about 816 ° C., preferably, it should not exceed about 788 ° C. The regeneration temperature in the dense bed is kept in the range of 621 ° -760 ° C, preferably around 677 ° C, in order to initiate and maintain further oxidation of carbon monoxide to carbon dioxide. Slightly lower temperatures may be used when the CO combustion is carried out in front of a catalyst. Dilute phase catalyst particles, now almost completely coke free, are separated from the hot regenerative gas stream by passing the catalyst particles through a series of cyclones with recycled catalysts. into the dense phase by means of cyclone legs. Alternatively, the recovered catalyst particles from the dilute phase may pass directly from the cyclone legs to a suitable conduit or vessel for recycling directly to the conversion reactor. The flue gas stream, usually containing some oxygen but substantially free of carbon monoxide, is discharged into the atmosphere or passed through suitable heat exchangers to recover the heat of the gases. Although control in the dilute-phase secondary regeneration zone can be achieved. partially by adding steam or spray water, preferably directed towards the cyclones or other internal parts of the regenerator, the diluted phase of the catalyst is preferably loaded with the amount of catalyst required so that the heat of combustion of CO is absorbed by the catalyst particles before their entry into the cyclones and return to the phase of the dense catalyst bed. A properly regulated and balanced load on the dilute phase may be achieved, for example, by using an appropriate gas velocity through the dense bed zone or preferably by circulating the catalyst, by suitable means of circulation, from the dense phase zone to the zone of dilute phase. Circulation of the catalyst can be accomplished, for example, by an independently controlled steam jet pump or a catalyst lift system, achieving increased heat transfer to the catalyst particles. Regenerated catalyst particles having an extremely low residual coke content, finally recovered from the dense phase zone, passes substantially at the temperature of the dense bed through a conduit to the conversion reactor to contact the grayish fresh hydrocarbon or mixtures thereof with the recycled hydrocarbon fraction. When the process of the invention is used in cracking a dust catalyst, the regenerated catalyst may be Recycling to the crack reactor at a much higher temperature, as well as more active than conventional processes. Many fluid crackers operate on a "thermal equilibrium" principle, dependent on the combustion of coke to release the heat required by the process. Such apparatuses fail to fully exploit the potential benefits of highly active zeolites or molecular sieves as catalysts that can be achieved in a reactor where the contact time of the catalyst with the oil vapors can be extremely short. high conversion with high selectivity, with a low ratio of catalyst to oil in the reactor, leads to less coke available in the reactor for generating the heat of combustion. Accordingly, an external heat source must be used or, alternatively, the plant must be operated at lower fresh hydrocarbon throughput. Such undesirable results are eliminated by the invention, which allows for the efficient recovery of additional heat by transferring regenerated catalyst particles to the reactor. The coke combustion heat in conventional operations is approximately 6,660 kcal. The method according to the invention increases the available heat to about 9435 kcal / kg. This greater heat of combustion raises the reactor temperature, lowers the coke level on the regenerated catalyst and lowers the catalyst circulation speed, giving higher yields at a given conversion level. 1 and 2 in the drawing explain the invention without limiting its scope. The regeneration of the exhausted catalyst from any suitable crude oil conversion process is very successful with the process of the invention, which can indeed be carried out in numerous existing crude oil conversion plants, especially fluid catalytic cracking plants without limitation. for bulky parts for cracking stripping and regeneration Fig. 1 explains one embodiment of the invention, using at the bottom of the inlet for the exhausted, exhausted regenerator catalyst. The withdrawn catalyst particles from the stripping zone enter through the bottom of the regenerator 1, passing up through the inlet lines 2 and 3 through the heads 4 and 5 into the dense catalyst bed. The dense phase catalyst bed is maintained in the lower part 6 of the regenerator and extends upward to the interface 7. The catalyst in the dense phase bed is fluidized by the flow of combustion air supplied through line 8 with valve 9 and line 10. to ring 11. Substantially even air flow through the regeneration zones is achieved by using additional air rings, not shown in the drawing. Combustion of the coke on the exhausted catalyst with the help of air begins in the dense phase bed. Higher temperatures can be achieved by the temporary combustion of a stream of burner oil, e.g. decant oil, in the bed. The oil is introduced through a line 12 with a valve 13 and a line 14 terminated with a nozzle 14, above the ring 11. The velocity of the air flowing through fluidization continuously lifts some particles of the catalyst up to the dilute phase zone which occupies the top 15 of the regenerator, i.e. above the phase boundary of the catalyst 7. Coke combustion continues in the dilute phase zone and the exhaust gas from combustion with the entrained catalyst passes into cyclones. separators 20 and 21. The majority of the catalyst particles are separated in the first cyclone stage and pass down via legs 22 and 23 to the dense phase zone. The gases and the rest of the catalyst particles pass through lines 24 and 25 between the cyclone stages to the second stage of the cyclone separators 26 and 27, where the remaining catalyst is substantially completely separated and passes down via legs 28 and 29 to the dense bed. Substantially exhausted combustion gas passes through lines 30 and 31 to vessel 32 and is finally removed from the regenerator through line 33. This may be accompanied by heat exchange, not shown in the drawing with the refined stream or for steam generation. The regenerated dense bed catalyst is removed through lines 35 and 34 equipped with manifold heads 36 and 37 to return to the catalytic conversion process. Although the supplied combustion air contains an excess of oxygen in relation to the amount required for complete combustion. coke on the catalyst particles to vapor and carbon dioxide, combustion of the coke in the dense bed phase is incomplete. The gases exiting the dense bed zone contain a significant amount of carbon monoxide, as well as carbon dioxide and oxygen. The remaining coke on the catalyst and the carbon monoxide are burned essentially completely in the dilute phase zone with much heat release. When the carbon monoxide burns in the dilute phase, the high temperature zone usually extends over a greater proportion of the dilute phase, especially in the part marked by X, and can easily be seen through a window not shown in the horizontal plane. the dilute phase is obtained in part by absorbing the heat in the bulk of the catalyst particles or by discharging the combustion gas upwards or by separating the combustion gas upwards from the dense bed by a jet vacuum pump 40 and catalyst separator heads 41 where the atomized particles the talcum powder is dispersed in the dilute phase zone. The catalyst is discharged by means of air, steam or other inert gas introduced through line 42 with valve 43 and spray tube 44 extending a short distance to the bottom of the vacuum jet pump 40. Temperature level too high in the top of the regenerator can be controlled by steam distribution, e.g., lines 45 and 46 with valve 47 and line 48 to steam drum 49. Temperatures in the vicinity of the air reservoir can also be controlled by steam, supplied from line 50, valve 51 and line 52 to the ring 53 surrounding reservoir 32. If cooling is required, it can be achieved by using a jet of water, not shown, which can preferably be directed towards the conductors of 24 and 25 inter-stage cycles. 2 explains an embodiment of the invention having a side inlet for exhausted catalyst in the regenerator and a counterflow of the catalyst and the regenerating gas. The exhausted catalyst enters the regenerator 121 via an inlet conduit 102 downstream of the regenerator to a dense catalyst bed held in a bottom 106 near the interface 107. Fluidization of the catalyst particles in the dense phase bed is reached. using the combustion air flow through line 108, valve 109 and line 110 to ring 111 for air. Additional rings not shown in the drawing may optionally be used to further balance the air flow pattern through the regeneration zones. As described in Fig. 1, the combustion of coke on the exhausted catalyst particles begins in the dense phase zone in which and, if desired, higher temperatures may be achieved by periodically burning the burner oil stream within the zone. This oil may be supplied through line 112, with valve 113 and line 114, terminated by nozzle. The velocity of the fluidizing air may be adjusted so that it constantly lifts the catalyst particles in the top 40 45 50 55 6098 590 11 12 to absorb heat in the air. in the dilute phase zone occupying the upper part 115 of the regenerator, that is, the part above the interphase plane 107. The combustion of coke and carbon monoxide continues in the dilute phase zone and the highly exhausted combustion gas along with the pore an important proportion of the catalyst particles pass to the cyclone separators 120 and 121. The major proportion of the catalyst particles is separated in the first cyclone stage and is removed via legs 122 and 123 into the dense zone. The gas and the rest of the catalyst particles in turn pass through lines 124 and 125 intermediate between the cyclone stages to the second stage separators 126 and 127, where substantially all of the remaining catalyst is separated and passed down via legs 128 and 125. 129 to the dense bed. Substantially exhausted combustion gas passes through lines 130 and 131 from air reservoir 132 and is removed from the regenerator through line 133. The regenerated dense bed catalyst is fed through lines 134 and 135 provided with manifold heads. 136 and 137 and recycled to the catalytic conversion process. As described in FIG. 1, the carbon monoxide burns in the dilute phase, forming a high temperature zone in the area of the dilute phase approximately located in the portion denoted by X. regeneration in the dilute phase zone is achieved by the absorption of heat in the mass of the catalyst particles lifted up by the stream of gases after combustion directed to The temperatures around the air reservoir, cyclone and connected lines are lowered by steam supplied through line 150, valve 151 and line 152 to a ring 153 surrounding air reservoir 132. Water sprays, not shown, may be used similarly. crude oil fractions include light gas oils, heavy gas oils, broad gas oil fractions, vacuum gas oils, kerosene, decanted oils, residual fractions, reduced crude oils derived from either of these fractions, and corresponding shale oil fractions, tar oil, synthetic, hydrogenated carbon, and the like. These fractions may be used alone or in any desired combination. Catalysts containing silica and / or alumina are suitable catalysts. Other refractory metal oxides such as magnesium or cyron may also be used as long as they are regenerable under the chosen conditions. Concerning catalytic cracking, catalysts consisting of a combination of silica and alumina, containing KK? -50% by weight of alumina, and in particular mixtures thereof with molecular sieves or crystalline aluminosilicates, are preferred. Mixtures of clay and alumina can be also use. Such catalysts are prepared by known methods such as impregnation, milling, coagulation, etc., provided that the finished catalyst must be in fluidizable form. Suitable molecular sieves are both naturally and synthetically present. ne aluminosilicates such as faujasite, chabazite, X-type and Y-type aluminosilicates, and ultra-durable, large-pore synthetic aluminosilicates. The metal ions are largely replaced by a-mono or hydrogen ions in a manner known per se. If a molecular sieve is added to the silica-alumina to obtain the crude oil catalytic cracking catalyst, its content in the fresh catalyst particles is 5 to 15% by weight, preferably 8 to 10% by weight. The molecular sieve cracking catalyst may contain as little as about 1% by weight of crystalline material. The stripping vessel is maintained substantially at a conversion reactor temperature of 454-566 ° C, preferably about 510 ° C. . The preferred stripper gas is steam, although nitrogen or other inert gas or flue gas may also be used. The gas is introduced under a pressure of typically 0.7-2.45 atm, sufficient to achieve substantially complete removal of the volatile components from the exhausted conversion catalyst. The regeneration stage (s) in the fluidized bed of the heavy phase is usually maintained under pressure. 0.35-0.7 atm, at 621-760 ° C, preferably about 677 ° C. The regenerating gas may be air, oxygen, oxygen-enriched air, or any other oxygen-containing gas mixture suitable for the combustion of coke deposited on the surface of silica, alumina and / or alumina. The regeneration gas enters the dense bed at the bottom of the regenerator from a blower or a compressor. A suitable fluidizing speed maintained in the dense bed stage (s) is 0.061-1.22 m / sec, preferably 0.152-0.91 m / sec. The regenerative gas fluidizing the dense bed is introduced into the regenerator with a slight excess. required for the complete combustion of the coke (carbon and hydrogen) to carbon dioxide and steam. The excess oxygen may be about 0.1-25% of the theoretical amount of oxygen drawn in, but preferably no excess of more than 10% is needed. For example, when air is used as a regeneration gas with a 10% excess air, only about 2Vt is present in the exhaust gas. oxygen volumetric. When there is a greater excess of oxygen introduced into the dense bed, the combustion of the coke and carbon monoxide is usually incomplete anyway, as the oxidized carbon usually turns into a nearly equimolar mixture of carbon monoxide and carbon dioxide. The material rising from the dense fluidized bed is not hot enough to initiate complete combustion of the carbon monoxide. This usually requires a temperature of at least about 649 ° C, preferably about 691 ° C. This temperature level may initially be achieved by burning the burner gas into a dense region with a corresponding increase in the amount of oxygen supplied to the regenerator, whereafter the combustion of carbon monoxide is continued without combustion of the burner gas. A flame or spark is another medium. combustion initiation. However, the regeneration gas entering the dilute phase zone usually contains 2-10%. volumetric oxygen, when air is used, sustaining CO combustion is achieved by obtaining additional air or oxygen at a point just above the interface of the dense and diluted catalyst slurry. The required temperature can be lowered by introducing the catalyst or combustion promoter into the regeneration zone. For example, a suitable metal rod, mesh or screen can be placed in the combustion zone. Alternatively, it is possible to add to the greynesses of the catalyst or introduce, at the boundary points of the catalyst plates in the regenerator, fluidizing metal compounds, in particular powdered transition metal oxides, e.g. iron oxide (Fe2O), manganese dioxide ( Mn02), rare metal oxides, etc. Iron oxide powder, fluidizing together with the conversion catalyst, may be added to the catalyst in an amount up to at least about 0.5% by weight, in particular about 0.2% by weight, with no appreciable adverse effects on the catalyst or the conversion process. further combustion of the carbon monoxide takes place quite abruptly at the temperature of the dense bed maintained, with most of the combustion actually taking place in the upper zone of the dilute phase as the gas stream rises sharply upward. There is less catalyst in the dilute phase and with less heat absorbing agent the temperature rises sharply. The burning of the carbon monoxide in the dilute phase can be observed visually through the sight glass. It is characterized by an intense orange flame or the so-called "fireball." The temperature remains higher than in the dense bed zone, preferably around 677-788 ° C, especially around 704-760 ° C. Such temperatures have been avoided in the past in the field of crude oil conversion due to the mechanical efficiency and durability as well as the quality of the catalyst. The effective control of the temperature in the dilute phase is achieved by maximizing the heat transfer to the catalyst particles in the dilute phase in the regenerator. This requires a significant increase in the range of the catalyst particles in the regenerator. This can be done by any suitable means, e.g. by increasing the gas velocity so that more catalyst is entrained into the dilute phase or otherwise loading on the phase diluted with hot catalyst from the dense phase. Such a load can advantageously be obtained by external circulation of the catalyst from the dense bed into the dilute phase zone j or by separation within the regenerator and a corresponding increase in the catalyst density. This evolution is achieved with a regulated stream of steam, air, inert gas, or a suitable combination thereof. This catalyst "heat reservoir" unexpectedly absorbs an excess of 80% of the heat of combustion of CO in the dilute phase zone, so that most of the thermal energy is conserved. in a cyclic system for use in endothermic hydrocarbon conversion or in a cracking zone. External water or steam treatment requires application only in exceptional cases, critical to the equipment, at a few points within the apex of the regenerator. For example, steam quenching may be used for the air reservoir, and the spraying of water or steam is used for cyclones, interstage lines in cyclones and suspended cyclones. The dilute phase catalyst is partially transferred to a separation zone, usually consisting of cyclone separators assembled in multiple stages, of which the catalyst is returned directly through the branches to the St. reefs of a dense bed. Extracted regeneration and combustion gases collected in the tank are removed after adequate recovery of the heat energy contained therein. The process of recovering heat from the flue gas includes steam generation, exhaust catalyst stripping, indirect heat exchange with various refining streams and in particular with the material being converted, and use in a variety of drying or evaporation devices. Heat recovery by absorption in the catalyst particles and the recycling of the catalyst to the dense phase also serves to ensure that a sufficiently high temperature is maintained in the dense phase zone. The temperature of the dense phase under relatively usual "equilibrium" conditions can approach about 704 ° C, so that the combustion of hard-to-remove coke becomes substantially complete at the end of the period. Regenerated dense phase catalyst containing about 0.01-0.10% by weight, preferably 0.01-0.05% by weight, most preferably about 0.01-0.03% by weight of carbon or coke is removed from the regenerator at a temperature of about 649 ° -760 ° C. , preferably around 677-704 ° C, and recycled to the conversion reactor, where it is mixed with fresh grease crude oil, possibly with its recycling or other hydrocarbon material, thus eliminating the need for additional preheating of the charge. Advantageous conversion of the regenerated angle. The lyser according to the invention is illustrated by the graphs in Fig. 3 in the drawing. Laboratory tests of the gas oil fraction were carried out with a conventional silica-alumina cracking catalyst containing about 25% by weight of alumina, designated as catalyst isator Biz with a molecular sieve catalyst containing silica-alumina as constituents and crystalline aluminosilicate, designated as Catalyst A. The catalyst reaction to carbon after regeneration was measured by the degree of conversion of the starting material and the gasoline yield (C5 - 221 ° C) with constant conversion. Extensive research on residual carbon content showed that the silica and alumina catalyst (Catalyst B) was almost insensitive, while the sieve catalyst (Catalyst A) was much more sensitive to these parameters and extremely sensitive. to low carbon levels on the catalyst. The incentive to remove coke from the catalyst as much as possible, especially to less than about 0.005% by weight, is evident. A further advantage of the new regeneration process is the extremely low carbon oxide content of the gas. exhaust from the regenerator. While the flue gas from conventional cracking catalyst regeneration typically contains about 6-10% carbon monoxide, a similar amount of carbon dioxide and very little oxygen, the flue gas from regeneration according to the invention generally contains less than 0.2%, and often no more than about 5 to 500 ppm of carbon monoxide. The oxygen content of the flue gas is not critical and may be about 0.1-10%, preferably 1-3%, especially not more than about 2%. From an ecological point of view, a very low level of carbon monoxide in the flue gas stream is highly desirable and corresponds to the existing ambient air quality standard. Indeed, if required, the remaining carbon monoxide can be burned in the regenerator exhaust stack, in the flue gas. From a process point of view, the recovery of the heat of combustion of the carbon monoxide in the CO boiler, downstream or downstream of the burner system, should be avoided, with the consequent substantial savings in terms of equipment and operating costs. The optimal application of the invention is in an integral part of the cracking process. fluidization using a fluidizable cracking catalyst such as a silica and alumina catalyst containing crystalline aluminosilicate constituent or a molecular sieve in a transfer reactor or reactor with suitable equipment to strip the exhausted, coated bun The catalyst and regeneration of this catalyst according to the method of the invention. Preferably, cracking only occurs in the reactor and no dense catalyst bed is used. Typically, a "riser" cracker is used to convert the gas oil, the Conversion Ratio (TPR) or volume ratio of the total starting material to fresh material being 1.0-2. The conversion level may be 40-100%, and preferably above about 60%, for example about 60-90%, Conversions are understood to mean the percentage reduction in boiling point above 221 ° C. and atmospheric pressure, by forming lighter materials or coke. The weight ratio of catalyst to oil in the reactors is 2-10, so that the fluid dispersion will have a density of 16.1-80.5 kg / m3. Preferably, the ratio of catalyst to oil is kept to no more than about 5. , most preferably about 3-5. The fluid velocity may be about 6.09-18.25 m / sec. The reactor may be substantially vertical with a length-to-diameter ratio of at least about 25. For the production of conventional products The mixed temperature at the bottom of the reactor is preferably u is kept at about 538 ° C for a substantially complete evaporation of the crude oil, so that a temperature of about 510 ° C is set at the tip portion. Under these conditions, taking into account the rapid separation of the exhausted catalyst from the exhaust vapors, a very short contact period is established between the catalyst and the oil. The contact time in the reactor is about 3-10 seconds, preferably about 3-7 seconds. A shorter contact time is more advantageous as most of the hydrocarbon cracking occurs during the initial increase in contact time and undesired secondary reactions are avoided. This is of particular importance when higher product yields and selectivity are to be realized while reducing the carbon formation. A short contact period of the catalyst particles and oil vapors is achieved by various means. For example, the catalyst may be injected at one or more points along the length of the lower or bottom part of the reactor. Likewise, the oily feed may be injected at one or more points along the length of the lower portion of the reactor, and different injection points may be used for fresh or recycled feed. For this purpose, the lower part of the reactor can be up to about 80%. of the entire length of the reactor for extremely short, effective contact time leading to optimal conversion of the crude oil feedstock. If a dense catalyst bed is used, the catalyst particles and / or feedstock are injected directly into the dense bed zone. With regard to the production of gasoline as a spark-ignition fuel in internal combustion engines, the process pattern can be varied accordingly, allowing for maximum production of heavy hydrocarbon products such as jet fuel, diesel fuel and heating oils. The examples illustrate the process of the invention without limiting its scope. EXAMPLE I. Gas oil (23.4 ° API), boiling at 343 ° -566 ° C, was cracked in a fluid conveyor-type reactor at an average cracking temperature of 516 ° C. The throughput ratio (total feed weight / fresh raw material weight) was 1.34 and the total feed rate was 572 m3 / day. The catalyst particles consisted of silica-alumina and 10% by weight of crystalline aluminosilicate or molecular sieve and circulated at a rate of 17.8 tons / minute. The weight ratio of catalyst to oil in the cracking zone was 3.7. Leakage from the reactor was led to the separation zone to the cyclone separator. The carbohydrate products were removed and the exhausted catalyst was directed down the leg of the separator into a stripper zone maintained at 510 ° C. The deposited catalyst was stripped of the steam to remove the remaining volatile material by regeneration. The discharged, exhausted catalyst containing 0.9 wt.% Coke was charged to the bottom of the regenerator, where it was fluidized with air in the catalyst bed in dense phase. kept at 677-679.5 ° C (average temperature 682 ° C) by burning the coke and occasionally burning the burner gas, if necessary. The air velocity was approximately 14.0 kg of air per kg of coke on exhausted catalyst. A portion of the catalyst entrained an upward stream of air and transferred it to the catalyst zone in a dilute phase at the top of the regenerator near the interface. The additional catalytic converter was carried upwards by three ejector conduits provided with dosing heads by means of a steam jet and dispersed to then fall down into the shape of a fountain. The combustion of the carbon monoxide in the dilute phase zone occurred. in the form of a spherical flame visible through the sight glass in the side wall of the regenerator. The temperature around the flame was 788 ° C. The gases and entrained catalyst passed from the dilute phase zone to a series of cyclone separators, the catalyst being returned directly to the dense phase zone. The cyclone inlet temperature was adjusted to approximately 760.degree. C. with the aid of the catalyst and with a stream of water as required, with the stream of water directed below the inlet to the cyclone system. The gas stream leaving the cyclone system first passed to the air reservoir on the top of the regenerator, then was removed outside at 677 ° C. The catalyst was removed from the dense phase bed and returned to the reactor via a line at 677 ° C. Analysis of the regenerated catalyst showed that the residual coke content was only 0.03 wt.%. The catalyst particles were white to light gray in color. The flue gas analysis showed that the carbon monoxide content was 0.0% by volume and the oxygen content was 1.9% by volume. The cracking conversion was 67.7% by volume of the raw material. The thermal equilibrium calculations show that the coke was burned at 9389.5 kg / hour, releasing 9879 kcal / kg. Of the total amount of heat released, more than 80% was absorbed in the regenerated catalyst and thus retained in the fluidized cracking cycle. Example II. Three test processes in a crude oil conversion unit with dust cracking were compared to previous operations on the same unit, with similar conversion levels and feed rates, as shown in Table 1. The catalyst used was of the type. molecular sieve, and the hydrocarbon feedstock was a mid-continental type oil gas. The comparison clearly shows the increase in gasoline yield (C5-221 ° C). With the reduction of the coke level on both exhausted and reclaimed catalysts and the corresponding increase in their activity, the catalyst circulation rate (regulated by the catalyst to oil ratio) is lowered in order to maintain the level of selective conversion. The content of carbon monoxide in the waste gas is considerably reduced and can be as much as about 0.0% by volume. Example III. The two test processes are compared in Table 2 with conventional process data based on the programmed computer at identical feed rates, conversion levels and average cracker reactor temperature. The weight ratio of catalyst to oil has been significantly reduced, which is reflected in the lower catalyst circulation rate sufficient to achieve the desired conversion when the catalyst is regenerated according to the invention. The gasoline yield (C5 - 221 ° C) increased significantly with very little change seen in the light products. This indicates a significant reduction in the yield of coke, resulting in an increase in the value of the cracking products. However, not only does the efficiency of gasoline increase, but the octane number is also higher, so that from a given amount of raw material more high-octane product suitable for blends is obtained. Example IV. Under test conditions similar to those of Example I (but without the use of a steam ejector tube), the minimum level of carbon monoxide, reasonably achieved in the regenerator stack, was determined. The amount of excess air varied while maintaining the temperature of the dense fluidized bed in the generator at 699-704 ° C and sampling the exhaust gas from the stack. The results summarized in Table 3 clearly show that a carbon monoxide level as low as 8 ppm can easily be achieved with the method of the invention. A simple extrapolation of these data suggests that it is not unreasonable to predict operations with the non-detection of carbon monoxide in the stack gas. Table 1 Comparative tests of catalyst regeneration Test period | 1 raw material, MB / D conversion% by volume Reactor mean temperature ° C atm pressure. catalyst circulation tons / min. weight ratio catalyst / oil Regenerator 1 A 2 29.9 68.0 505.5 1.197 J 18.7, 2 B 3 29.4 71.5 515.5 1.40, 5 6.0 2 A 4 41.0 61.4 502.2 1.344 19.7 4.1 B 40.6 59.4 504.4 149.1 31.3 6.5 3 A 6 39.7 66.3 515.5 1.302 19.9 4, 2 B 7 ¦ 38.0 67.4 515.5 1.435 26.7, 498 590 19 20 cd table 1 1 temperature ° C dense bed temperature ° C inlet to the cyclone coke combustion M kg / hour. carbon on exhausted catalyst%. % by weight carbon over regenerated catalyst% weight ratio air / coke exhaust gas% weight by volume. co2 .co- .. co2 products: dry gas + Cj isobutane% by volume n-butane tyo by volume and cylinders tyo by volume C5 - 221 ° C tyo by volume coke ©, weight 2 658.8 748.9 7.9 0.85 0.05 14.7 16.0 0.0 1.7 7.8 4.6 1.4 7.0 56.8 4.7 3 651.1 654.4 11.5 1.18 0.37 - 11.2, 6 9.4 0.4 9.7 6.2 1.6 7.4 52.2 6.6 4 670.5 746.7 9.3 0.77 0.04 14.0 16.4 0.5 1.0 6.7 4.0 1.3 6.6 51.1 - 3.9 634.9 615.6 13.0 1.00 0.35 11.2.0 9, 6 0.4 6.9 4.5 2.2, 8 47.0 4.9 6 679.4 753.3 9.7 0.80 0.03 14.6 16.0 0.2 2.1 8 , 6 4.0 1.3 7.2 54.3 4.1 7 1 651.1 640.5 12.7 • 0.97 0.22 11.4, 6 9.6 0.7 8.2, 1 1,3 '0,0 51,9, 7 A - test period B — known process Table 2 Comparison of actual and simulated data Test period ~~~ ~~~~ 1 ^ raw material, B / D conversion you * volume Reactor average temperature in ° C catalyst circulation tons / min. catalyst / oil ratio Regenerator dense bed temperature ° C cyclone inlet temperature ° C coke combustion, M kg / h. carbon with exhausted catalyst • / »carbon by weight on regenerated catalyst by weight Ca and lighter products type volumetric isobutane% volumetric n-butane tyo volumetric buten tyo volumetric pentanes tya volumetric pentenes tito volumetric C6 - 221 ° cctane volumetric coke titanium No. (RM + 3 cm8) 1 imitated 2 * ~ 41.378 61.8 506.7 32.6, 3 617.2 - 13.6 1.06 0.34 11.84, 24 1.49 6.33 4, 19 3.65 46.96.54 89.75 actual 3 41.378 61.8 506.7 18.1 3.5 673.8 750.6 9.1 0.86 0.03 11.87 3.43 0, 98, 98 3.27 3.48 51.05 3.70 90.40 2 imitated 4.904 67.7 515.6 34.0 6.1 617.2 - 13.2 0.96 0.34 14, 67, 85 1.74 7.57 4.83 4.00 49.88 6.15 89.7 actual, 904 67.7 515.6 17.8 3.7 681.7 743.9 • 9.4 0 , 91 0.03, 99 4.20 0.94 7.13 3.14 and 4.16 52.70 4.39 90.321 98 590 22 Table 3 The results of excess oxygen for the content of carbon monoxide in the flue gas Regenerator bed temperature dense in ° G 702.2, 701.6 697.2 699.4 706.1 • Flue gas analysis oxygen volume% 0.55 a 1, 18 1.18 1.59 2.40 2.43 2.60 2.7 2.9 3.2 3.0 3.0 CO, ppm 2400t 2700 280 1500 100 70 36 11 8 17 volumetric 14.3 'c, 7, 9 16.6, 7, 9, 4, 3, 9, 8, 6 16.2 | a - oxygen analyzes obtained with Hays Acatron, Serial M 2990, scale 0-5 ° / *, b - carbon monoxide analyzes obtained with Union Carbide, Model 3020, Carbon Monoxide Analyzer, c - carbon dioxide analyzes carried out using the method Orsata. PL

Claims (3)

Claims 1. Continuous catalytic cracking of crude oil in a cyclic system, using a fluidized catalyst, consisting in the removal of a fluidizable cracking catalyst from the reaction zone, which has been inactivated by coke deposits, removing the volatile matter, reactivating the catalyst by burning the zen of the coke in a fluidized regeneration zone consisting of a lower section of the dense phase of catalyst particles and an upper section of a thin phase of catalyst particles, and returning the regenerated catalyst to the reaction zone, characterized by the deactivated catalyst particles contacts the regenerative gas containing oxygen in the regeneration zone, providing an excess of oxygen to the theoretical amount needed to complete the conversion of all coke from the deactivated catalyst to carbon dioxide, vaporizes and burns practically all coke to the deactivation catalyst, it takes root and the combustion of the carbon monoxide produced during firing is maintained in the regeneration zone by contacting it with an oxygen-containing regeneration gas while in contact with the catalyst particles, in order to cause virtually complete combustion of the carbon monoxide to carbon dioxide, with most of the heat generated during combustion being absorbed by the catalyst particles, and then from the regeneration zone, the low-carbon off-gas and the low-coke regenerated catalyst are fed. 2. The method according to claim The process of claim 1, wherein virtually all of the coke and carbon monoxide burns out in the dense section of the regeneration zone. 3. The method according to p. The process of claim 1, wherein the temperature in the regeneration zone is 621-816 ° C. 4. The method according to p. The process of claim 1, wherein the coke burns off the catalyst in the lower dense phase at the first temperature and the combustion of the carbon monoxide ends in the upper thin phase catalyst at the second temperature which is equal to or greater than the first temperature. 5. The method according to p. The process of claim 4, wherein the combustion is carried out at a second temperature higher than the first temperature and the catalyst particles are circulated from the lower to the higher regeneration zone. 6. The method according to p. The process of claim 5, characterized in that the regeneration temperature in the lower section of the regeneration zone is kept in the range of 621-760 ° C and the regeneration temperature in the upper section of the regeneration zone is in the range of 649-816 ° C. 7. The method according to p. The process of claim 5, characterized in that the catalyst particles are circulated upwards from the lower section of the dense phase to the higher section of the rarefied regeneration zone and are dispersed in the dilute phase in an amount sufficient to absorb practically all of the combustion heat, depending on the diluted temperature upper phase. 8. The method according to p. The process as claimed in claim 5, characterized in that the catalyst particles are circulated from the lower phase to the higher regeneration zone in an amount sufficient to absorb more than 80% of the heat generated during the combustion of carbon monoxide in the higher dilute phase. 9. The method according to p. The process as claimed in claim 5, characterized in that the catalyst particles are circulated from the dense phase to the dilute phase by directing the particles through a through-tube with a jet pump extending from the dense phase to the dilute phase. 10.. 10. The method according to p. 4. The process of claim 4, characterized in that the combustion of carbon monoxide in the top section of the regeneration zone is initiated by the combustion of a sufficient amount of burner oil in the dense zone, while introducing into this zone sufficient oxygen-containing gas to completely burn the burner oil. thereby allowing the exhausted regenerative gas to partially flow upwards to the upper section at a temperature high enough to maintain the combustion of the carbon monoxide, and then the burner oil is burned out. 11. The method according to p. The process of claim 4, wherein the combustion of carbon monoxide in the upper section of the regeneration zone is initiated by switching on an ignition device located inside the upper section near its bottom, and then the ignition is switched off. 12. The method according to p. A process as claimed in claim 11, characterized in that the regenerated catalyst particles are withdrawn from the regeneration zone at a location near the upper part of the lower phase of the dense regeneration zone at a temperature of at least 676.7 ° C. 13. The method according to p. The process of claim 1, wherein most of the coke is burned out from the catalyst in the lower dense phase, substantially all of the remaining coke from the catalyst in the higher dilute phase, with whereby the combustion of carbon monoxide ends in the upper rarefied phase. 14. The method according to p. The process of claim 13, wherein the lower phase is maintained at the first temperature and the higher phase is held at a second temperature equal to or greater than the first temperature, the second temperature being 648.9-787.8 ° C. . 15. The method according to p. The process of claim 1, characterized in that oxygen-enriched air is used as the oxygen-containing regeneration gas. 16. The method according to p. The process of claim 1, wherein the regeneration gas is passed through the regeneration zone at a rate of 0.15-0.92 m / sec. 17. The method according to p. A process as claimed in claim 1, characterized in that oxygen is used in an excess of 0.1-25% of the theoretical amount needed to convert the sludge to carbon dioxide and vapor. 18. The method according to p. A process as claimed in claim 1, characterized in that an outlet gas containing less than 0.2% by volume of carbon monoxide and particles of regenerated catalyst containing up to 0.05% by weight of coke is discharged from the regeneration zone. 19. The method according to claim The process of claim 1, wherein the regenerated catalyst particles containing up to 0.1% by weight of coke are discharged from the regeneration zone. 20. The method according to claim The process of claim 1, wherein more than 80% of the total heat generated during the combustion of coke and carbon monoxide is absorbed, this heat being taken over by the catalyst particles which circulate in the regeneration zone. 5 / rSO &&59O Fig. 2 133 weight content of La on the regenerated Fiq catalyst. 3. PL