KR930011920B1 - Process for catalystic cracking of hydrocarbons - Google Patents

Abstract

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Description

Process and apparatus for catalytic cracking of hydrocarbons

The accompanying drawings are schematic diagrams of the process and apparatus of the present invention as shown in the combination fluidization catalytic cracking-regeneration operation, each of which is provided with two riser reactors, a heavy hydrocarbon feed and a light naphtha feed. Are catalytically cracked independently, and catalyst regeneration is carried out continuously in two separate relative hot and cold zones.

* Explanation of symbols for main parts of the drawings

6: feed spray nozzles 8, 108: riser reactor

20: container 28: cyclone separator

38: bed 54: catalyst

58: second catalyst regeneration zone 98: fractional distillation column

102: compressor 106: gas separation plant

134: Steam Generator

The present invention relates to the field of fluidized catalytic cracking of hydrocarbon feeds. In particular, the present invention relates to an improved process and apparatus for catalytic cracking hydrocarbon feeds at high temperatures, wherein the catalyst regeneration is carried out in two stages, including the development of relatively low and high temperature regeneration steps. The feed is controlled to obtain improved yields of the light cycle oil / distillate, C ₃ -C ₄ olefins, and high octane mixtures and distribution of the desired product. The present invention, on the other hand, relates to an improved process and apparatus for catalytic cracking hydrocarbon feedstocks, which relates the activity and selectivity of the catalyst to process variables to improve the conversion of the soluble oil material.

[Background of invention]

Combination fluidization catalytic cracking (F11) -regeneration processes are known, in which the hydrocarbon feed is continuously regenerated and free to move under conditions capable of conversion to soluble products such as olefins, fuel oils, gasoline and gasoline mixtures. Is contacted with the micronized particulate catalyst material. High boiling point partial conversion of crude oil including heavy components and vacuum gas oils commonly referred to as simple heavy hydrocarbons or crude oil above the distillation column, distillation column bottoms under atmospheric pressure, vacuum residue, reduced crude oil and residual oil, etc. The FCC process for such has been of particular interest in recent years as the need for the availability of light hydrocarbon feedstocks that are more readily degraded. Relatively large amounts of coke, such as polycyclic aromatics and asphalins, can be deposited on the catalyst during decomposition and are usually used for heavy hydrocarbon feed materials such as those that require extreme operating conditions that include very high temperatures. Decomposition has raised issues related to the construction of the plant and damage to the catalyst.

At present, there are several processes that can be used for fluidized catalytic cracking of such heavy hydrocarbon feeds. Particularly successful and highly preferred approaches to avoid problems as mentioned above are described, for example, in US Pat. Nos. 4, 664, 778, 4, 601, 814, 4, 336, 160, 4, 332, 674 And 4, 311, 533.

In the above process, a combination fluidization catalytic cracking-regeneration operation is provided where catalyst regeneration is successfully swept in separate, relatively low and high temperature regeneration zones, each of which is characterized by very limited catalyst damage per catalyst regeneration cycle. Together the high temperatures are operated independently under selected conditions to provide a fully regenerated catalyst. Such hot regenerated catalysts are then employed for high temperature, highly selective catalytic cracking and the simultaneous conversion of high and low boiling contained in the heavy hydrocarbon feed.

Due to the nature of the heavy hydrocarbon feed, decomposition in the FCC process as described above increases the selectivity that tends to produce light cycle gas-oil and high boiling materials. These products are often employed as components of desirable diesel fuel and furnace oil after hydrotreatment or caustic treating, but catalytic cracking of such feeds is used as gasoline blend material, or gasoline blend material. There is a tendency to oppose the selectivity as a low boiling component for use as a precursor for synthesizing, especially for those of high octane number. Such competing effects are believed to be due in part to carbon laydown on the catalyst as it is transported through the region in the reactor. As the amount of carbon on the catalyst increases along the reaction path, the selectivity of gasoline and light olefins from the light feed decreases. The higher the molecular weight of the feed hydrocarbon, the higher the molecular weight components, including more polynuclear aromatic components and asphaltenes, tend to produce more coke at the first decomposition and evaporation than the other components. The carbon contention effect is further increased, among the aromatic components, the polynuclear components not only decompose at a low rate, but also have higher selectivity for C2 and light gas and coke products, while the alkyl side chains of the naphthenic components And mono-and di-aromatics not only decompose at a high rate but also exhibit high selectivity for the desired light olefins and gasoline such as polypropylene, butene, pentene and hexene.

Thus, if such a heavy hydrocarbon feed undergoes decomposition, the heavy hydrocarbon feed constituents reduce excessive coke production, limiting the possible decomposition of common paraffinic side chains and as much of the mono- and di-aromatics as possible. In order to do so, they stay for a reduced stay at extremely high temperatures. Optionally, the selectivity of gasoline is optimized by deeper catalytic cracking operations of light hydrocarbon feeds, e.g. higher catalyst-to-oil ratios, longer residence times and relatively higher than those desired in the heavy feed sector. Temperature and so on.

It is often desirable to manipulate the FCC process in a manner that maximizes the production of a given product or products, especially in the absence of such competitive effects. For example, to produce large quantities of high octane gasoline and gasoline precursors, while either or both of gasoline / light olefins and light cycle oil products are produced simultaneously with increased amounts of fuel oil distillate and diesel fuel. May be This is especially true in light of the current environmental concerns that have made it necessary to reduce the pollution of automobile combustion by-products using leaded gasoline products. Therefore, there is a great need for lead-free gasoline blends with high octane numbers.

Thus, the operating conditions of the useful process described above are expanded to increased selectivity for high octane number materials and light olefins, while at the same time economical heavy hydrocarbon feeds are heavy naphtha and distillate or light cycle and heavy cycle oils. And simultaneous decomposition to selective high boiling materials.

There are several ways to achieve this goal. The method described in U.S. Patent No. 3, 617, 497 separates the hydrocarbon feed to load a relatively low molecular weight feed fraction or fractions near the bottom of the extended riser reaction zone and gradually to the top of the riser. Introduces the loading of relatively high molecular weight feed fractions or fractions. The cracking of the light hydrocarbons feed in the absence of a heavy hydrocarbons feed is carried out in catalysts of low carbon content to maximize gasoline selectivity. Although the feed dwell time can be set in this process by controlling the total hydrocarbon load ratio to the riser, the catalyst to oil ratio and reaction temperature are individually optimized for maximum gasoline and light cycle oil selectivity. it's difficult.

More versatile methods for optimizing the degradation selectivity from relative high and low boiling feeds are described in US Pat. Nos. 3, 617, 496. In such a process, cracking selectivity for gasoline products is improved by classifying the feed hydrocarbons into relatively high and low molecular weight fractions. The fractions can be cracked into gasoline and loaded into a separate riser reactor. In this way, the relative light and heavy hydrocarbon feed fractions are decomposed in separate risers in the absence of each other, allowing for the manipulation of light hydrocarbon risers under conditions favorable for gasoline selectivity and the conditions above are the laydown of heavy carbon. To reduce the temperature of the hydrocarbon feedstock, to control the hydrocarbon feed dwell time, to control the weight ratio of the catalyst to the hydrocarbon feed, and so on.

Other processes likewise employing the use of two or more separate riser reactors to decompose a hydrocarbon feed are described below. US Pat. No. 3, 993, 556 decomposes heavy and light gas oils in separate risers to obtain improved yields of naphtha at high octane ratios. U.S. Patent No. 3,928,172 describes the cracking of direct current naphtha and / or heavy naphtha and gas oil boiling range feeds in separate cracking zones to recover light olefins, high octane mixtures, and highly volatile gasoline for alkylation reactions and the like. Is introduced. U. S. Patent No. 3, 894, 935 introduces a C ₃ -C ₄ enriched fraction in a separate conversion zone and catalytic cracking of heavy hydrocarbons, such as residual materials and gas oil. U.S. Patent Nos. 3,751,359 introduce the decomposition of intermediate cycle gas oil and direct gas oil, which are recycled in separate feeds and cycle risers. In US Pat. No. 3, 448, 037, direct gas oil and cracked cycle gas oils such as intermediate cycle gas oils are individually cracked through separate extended reaction zones to recover high gasoline products. U. S. Patent No. 3, 424, 672 introduces an increase in gasoline boiling range products by cracking light reformed gasoline, upper crude oil and low octane, in separate risers. U. S. Patent No. 2, 900, 325 discloses heavy gas oils such as gas oil, residual oil, etc. in the first reaction zone, and different feeds or similar such as cycle oil in the second reaction zone, operated under different conditions. It is introduced to break down the feed to produce high octane gasoline.

[Summary of invention]

It is an object of the present invention to provide an improved process and apparatus for catalytic cracking a hydrocarbon feed material at high temperatures, wherein regeneration of the catalyst is carried out in two or more stages including separate relative high and low temperature regeneration steps. .

It is another object of the present invention to provide a controlled process for obtaining the desired product distribution and improved yield of high octane gasoline blends and light olefins.

Another object of the present invention is to relate the activity and selectivity of the catalyst to the processing parameters of the individual heavy hydrocarbons and naphtha boiling range materials, thus developing their selective conversion into light cycle gas oil and the gasoline mixture and light olefins. It is an object of the present invention to provide an improved process and apparatus for catalytically cracking hydrocarbon feed materials at elevated temperatures.

Additional objects of the present invention will become apparent from the following description.

To this end, the present invention provides an improved combination fluidization catalytic cracking-regeneration process for cracking hydrocarbon feeds or vapors thereof as catalytic cracking comprising separate first and second catalyst regenerative zones, wherein the catalyst Is continuously regenerated in the first and second zones, which under the conditions effective to produce a first regeneration zone flue gas relatively rich in carbon monoxide and a second regeneration zone flue gas relatively rich in carbon dioxide, By burning hydrocarbonaceous deposits on the catalyst in the presence of a containing gas, wherein the temperature in the first regeneration zone is from about 1100 ° F. to about 1300 ° F., and the temperature in the second regeneration zone is from about 1300 ° F. up to about 1800 ° C. ℉.

The improvement in this process is the regeneration of the regenerated cracked catalyst supplied from the second catalyst regeneration zone at temperatures ranging from 1300 ° F. up to 1800 ° F., catalyst to oil rate 5-10, process stay time 1-4 seconds. Cracking the first hydrocarbon feed comprising gas-oil or residual oil, or mixtures thereof, boiling range material in the first extended riser reactor in the presence of coke in an amount of less than 1.2 weight percent. Deposited on the catalyst to obtain an evaporative conversion product of the first hydrocarbon feed, which is lower boiling than heavy naphtha fraction and heavy naphtha fraction, higher boiling than heavy gas cycle oil. Cycle and heavy cycle gas oils and the like. During cracking of the first hydrocarbon feed in the manner described above, a second hydrocarbon feed comprising a virgin, heavy or light FCC naphtha boiling range material may be used at 1300 ° F up to 1800 ° F. Decomposition simultaneously in a second extended riser reactor in the presence of a regenerated cracking catalyst supplied from a second regeneration zone, in the temperature range, catalyst to oil ratio of 3 to 12, and residence time of 1 to 5 seconds. Wherein coke is deposited on the catalyst in an amount of less than 0.5 weight percent to evaporate the second hydrocarbon feed comprising a low boiling range material that is generally olefinic in nature and a gasoline boiling range material having a high octane number. You get a sex conversion product. The evaporative conversion products from the first and second extended riser reactors are combined in a separate disengaging space to separate entrained catalyst particles from the evaporative product, which is then separated into separate products. Passed into kind area.

As will be appreciated by those skilled in the art, the main advantage of the present invention is the flexibility to select the operating conditions simultaneously, which operating conditions of selected hydrocarbon feeds and available refined materials to the desired product. It is particularly appropriate to achieve the desired optimal transmission. In particular, the new installation of the apparatus and treatment concept of the present invention, as will be discussed more fully below, will sufficiently avoid the problems associated with the hot regenerator and catalyst temperatures present in the catalytic cracking of high-boiling hydrocarbon feedstocks, so that gasoline and low boiling Produces hydrocarbon components and high boiling hydrocarbon components. The high boiling hydrocarbon feeds are generally referred to as heavy hydrocarbons and boil for the first time at least 400 ° F or higher. Preferred conditions for cracking such feeds can thus be encouraged in each riser reactor. Furthermore, in addition to the light olefins useful as gasoline precursors via, for example, alkylation, it is necessary to selectively cause the desired decomposition reaction of the naphtha boiling range feedstock to the high octane gasoline in each riser reactor. Stringent conditions can be encouraged. Increased reaction temperature also benefits the present invention. Increased catalyst-to-oil ratios and unit operating pressures can be taken in extended carbonaceous medium stay times in contact with the catalyst.

The apparatus and process of the present invention will be well understood in the foregoing description of the following specific embodiments and in the accompanying drawings which illustrate such embodiments. It is to be understood, however, that such embodiments are not intended to limit the invention, as many modifications may be made without departing from the spirit of the invention within the scope of the claims.

Description of Specific Embodiments of the Invention

The catalytic cracking process of the present invention comprises a high boiling residual hydrocarbon comprising a metallo-organic compound and the like, a topped crude oil, a reduced crude oil, a gas oil comprising residual components, It relates to the decomposition of economically obtained heavy hydrocarbon feed materials, generally referred to as residual oil and gas oil and the like. The foregoing are among several terms used in the art to describe parts of crude oil such as gas oil with or without a high boiling hydrocarbon feed, which is essential for metal-organic compounds and other heavy hydrocarbon feeds. It may be small. The heavy hydrocarbon feed has at least 2 weight percent of Conradson carbon initially boiling at at least 400 degrees F, with approximately 20 weight percent or more components boiling at about 1000 degrees F or more.

Products obtained from the decomposition of such feedstock include, but are not limited to: That is, gasoline boiling range products boiling from C ₅ to 425 ° F. and gasoline, light cycle oil boiling at a range of 425 ° F. to 600/670 ° F., products boiling at higher temperatures than light cycle oil, and up to 800 ° F. and above. Heavy cycle oil products including boiling at, slurry oil boiling at up to 970 ° F. from about 670 ° F., and the like. Additionally, heavy cracked naphtha is produced by attracting the tip of the light cycle oil to distillate or separately produced, which boils in the range of 330 ° F to 425 ° F.

The present invention also relates to hard, heavy and intermediate virgin naphthas boiling in the range of 10 ° F. to 450 ° F., among others, high octane gasoline, light ore for alkylation. To produce fins, or to produce high octane mixtures or petrochemicals in connection with other reactions, and to produce normal light cycle oil flows.

A heavy hydrocarbon feed, typically comprising a mixture of residual oil and vacuum gas oil, is introduced into the first elongated riser reactor where there is a highly active freshly regenerated cracking catalyst at a temperature of at least about 1300 ° F. or more. Mixed with The hydrocarbon feed is preferably first mixed with other gases or flows at these temperatures and conditions which form a highly atomized feed stream, which is then formed with a hot regeneration catalyst to form a generally evaporative hydrocarbon-catalyst suspension. After the catalytic conversion of the hydrocarbon feed material, a suspension separation device or a dispensing vessel comprising a separator cyclones employed at the riser outlet, for example, may be used. Separation from evaporative hydrocarbon feedstocks including cracking conversion products.

Simultaneously or separately from such an operation, the naphtha feed is at a temperature of at least 1300 ° F. and under conditions such that mixing with a hot regenerated cracking catalyst is obtained and under conditions such that an evaporative hydrocarbon-catalyst suspension is formed. Introduced into a second extended riser reactor, and then catalytic conversion of the naphtha feed material flows from the riser outlet into a disengagement device, thereby introducing the entrained catalyst from the additionally decomposed conversion product and the evaporative material. Separate.

Evaporative hydrocarbon products that have been combined leaving the separator cyclone are separated in the downstream fractional column into products which will be discussed more fully later. The spent catalyst particles recovered from each individual riser reactor in the cracking operation are then subjected to treatment of the incorporated hydrocarbon material through treatment with steam or other suitable stripping gas at high temperatures ranging from about 800 ° F. to about 1050 ° F. Strip and then pass continuously to the first and second (relative hot and cold) catalyst regeneration zones. This is described, for example, in US Pat. Nos. 4, 664, 778, 4, 601, 814, 4, 336, 160, 4, 332, 674, and 4,331,533 and the like, and is incorporated herein by reference. Included.

Generally in this process, the stripped consuming catalyst is rich in fluid bed of catalyst in a first catalyst regeneration zone maintained at a limited temperature and in an oxygen condition below about 1300 ° F. and preferably not above about 1260 ° F. Pass by. The combustion of coke or hydrocarbonaceous material deposited on the consumption catalyst in the first regenerator zone is carried out at relatively mild temperatures and conditions sufficient to sufficiently burn some of the carbon and all the hydrogen present in the coke deposits. The regenerator temperature is therefore preferably limited to temperatures and conditions that do not accelerate the deactivation of the catalyst, which inactivation occurs by exceeding the hydrothermal stability of the catalyst or the metallurgical limits of conventional low temperature regenerator operation. Flue gas, which is relatively rich in carbon monoxide, can be recovered from the first regenerator zone and directed to a carbon monoxide boiler or incinerator, for example, to be combined with the flue gas flow of other processes. Earlier, steam is generated by promoting safer burning of soluble tin monoxide. The combined flow as described above passes through a power recovery prime mover section to generate process compressed air in the manner described in the attached US Patent Application Nos. 273, 266, which are incorporated herein. Included for reference.

Partially regenerated catalyst containing a carbon residue and of limited temperature is recovered from the first regeneration zone with little hydrogen in the coke and passes to a separate, second, non-limiting high temperature catalyst regeneration zone, where the remaining relative As a result, carbon-rich coke deposits are almost completely burned to carbon dioxide in the extreme vapor atmosphere resulting from combustion of water or other sources, at high catalyst temperatures ranging from 1300 ° F to 1600 ° F and possibly 1800 ° F. .

The second regeneration zone is designed to limit the catalyst residence time at high temperatures, while the carbon needed to have less than about 0.05 weight percent and more preferably less than about 0.03 weight percent of residual carbon on the hot catalyst particles that have been recycled Achieve combustion rate.

The hot flue gas obtained from the second regeneration zone is combined with the first regeneration zone flue gas previously burned in the manner described above to the outer cyclone to recover entrained catalyst fines prior to further use. Can be supplied.

The hot, fully regenerated catalyst particles then go through the respective catalyst integration zones and tubes to the first and second riser reactors for further decomposition operation in the manner described above.

The subject apparatus carrying out the process of the invention is a combination catalyst-regeneration operation comprising separate first and second catalyst regeneration zones, operated at relatively high and low temperatures, operated under the conditions as described above, thereby Under operating parameters that allow for selective conversion, the first and second extended riser reactors, which independently catalytically crack each hydrocarbon feed, are fed with hot recycled catalyst. A fractional distillation zone is provided to receive the cracked production mixture from the first and second riser reactors to separate the product therein.

Referring to the drawings, there is shown an apparatus adapted to carry out a preferred embodiment of the inventive process. Accordingly, first and second extended hydrocarbon riser reactors 8,108 are provided separately, wherein the new high boiling heavy hydrocarbons to be catalytically cracked, usually comprising gas oil or residual oil or mixtures thereof. The feed is introduced into the bottom of the first riser reactor 8 by the conduit means 4 via multiple flows in the riser cross-sectional area loaded through a plurality of horizontally spaced feed spray nozzles indicated by the spray nozzles 6. do. Such a nozzle is preferably a supply spray nozzle for spray of the type described, for example, in US Pat. No. 4,434,049, or may be any other high energy spray source as appropriate. The patent application is incorporated herein by reference. Vapor, flue gas, carbon dioxide or other suitable gas may be introduced into the feed injection nozzle through the tube means 2 as a gasification, fluidization or dilution medium to facilitate the evaporation and atomization of the hydrocarbon feed.

The hot regenerated catalyst is introduced by the bottom conduit means 10 of the riser reactor 8 and flows upwards to an amount sufficient to form a suspension with a hydrocarbon feed or a hot evaporated mixture. 8) Mixed with multiple hydrocarbon feed streams in cross section. The hot suspension formed as above, including hydrocarbons, diluents and fluidized gases, suspended (fluidized) catalysts, and the like, is then passed through a riser 8 that is operated in a manner well known in the art.

The cracking conditions in riser 8 which produce cracking products comprising heavy cracking oil, cracked gasoline and light olefins from heavy feeds of high boiling components are well known. Heavy feeds containing high molecular weight components tend to contain significant amounts of polynuclear aromatics, which yield more coke on degradation than other compounds, with the desired product being degraded to low selectivity, It has high selectivity for C ₂ and hard gases and coke. It is therefore desirable for the heavy hydrocarbon feed components to be at a relatively reduced residence time at high temperatures in order to obtain high octane gasoline and light cycle oil yields, and to end operations prior to condensation or significant degradation of polyaromatics. Causes excessive coke formation and the production of excess C ₂ and light gases. Decomposition conditions preferably include a nominal residence time of 1 to 4 seconds and have the following riser temperature distribution: Regenerated catalyst temperature of 1300 ° F to 1690 ° F, feed preheating temperature of 250 ° F to 750 ° F, mixing zone effluent temperature of 1000 ° F to 1100 ° F, inlet temperature of the catalytic zone from 900 ° F to 1100 ° F, 870 ° F To a riser reactor outlet temperature of 10 to 3030 ° F., and a riser pressure of 15 to 40 psig. The catalyst to oil ratio based on the total feed can be 5 to 10 and the coke on the regenerated catalyst ranges from 0.3 to 1.2 weight percent. The amount of diluent added through the tubing means 2 may vary depending on the ratio of hydrocarbon to diluent required for control purposes. For example, if steam is employed as the diluent, it may be present in an amount of about 2 to 8 weight percent based on hydrocarbon load.

The first riser reactor 8 effluent comprising the suspended catalyst particles comprising the cracked product of the catalytic conversion and the evaporated mixture is suspended from the upper end of the riser 8 by a sign 26 such as an inertial separator. It is passed to the outlet via initial separation in the water separator means and / or to one or more cyclone separators 28 located at the top of the vessel 20 for further separation of volatile hydrocarbons from the catalyst particles. Separated evaporative hydrocarbons, diluents, gaseous materials for strips, etc., are attracted by the tube 90 for passage to product recovery equipment, which will be described more fully later.

Catalysts consumed from the decomposition process separated by cyclone 28 and means 26, with coke or hydrocarbonaceous products from heavy hydrocarbon cracking and metal contaminants deposited thereon, may be deposited at the bottom of vessel 20. As a bed of catalyst 30. A stripping gas, such as steam, is introduced into the bottom bottom of the bed by tubing means 32. The stripped catalyst passes from the vessel 20 into the catalyst holding vessel 34 and is regenerated in the vessel 40, which is the first catalyst regeneration region, through the flow control valve V ₃₄ and the conduit means 36. It goes to the bed of the catalyst 38 being used. Oxygen-containing regeneration gas, such as air, is introduced into the bottom of the bed 38 by tubing means 42 connected with the air distribution ring 44.

The regeneration zone 40 operated in accordance with procedures known in the art is a relatively low temperature regeneration operation which is generally associated with hydrocarbon materials deposited from catalytic cracking and conditions of 1300 ° F. and below, preferably 1260 ° F. and below. It is maintained under selected conditions to achieve removal of all hydrogen and carbon deposits and minimal partial combustion.

Combustion in the first regeneration zone 40 takes place under conditions that form a first regeneration zone flue gas flow enriched with carbon monoxide. Said flue gas flow is separated from the catalyst fine powder which has been introduced by one or more cyclone separation means as indicated by reference numeral 46. The catalyst separated from the flue gas enriched by carbon monoxide by cyclone is returned to the catalyst bed 38 by an appropriate diple. The flue gas enriched with carbon monoxide recovered from the cyclone separation means 46 in the first regeneration zone by the tubing means 50, in the manner discussed above, is proliferated with other process flue gas flows to produce a power recovery main motor. Prior to passage, for example, steam is generated by complete combustion of the available carbon monoxide therein towards a carbon monoxide boiler or incinerator (not shown) and / or flue gas cooler (not shown). In the first playback area, the playback conditions are intended to be selected as follows. That is, sufficient residual carbon remains on the catalyst and preferably the temperature of the catalyst particles as needed to more completely remove carbon from the catalyst particles by combustion with the transient coral containing gas in the second catalyst regeneration zone discussed later. The catalyst is only partially regenerated in the removal of hydrocarbonaceous deposits such that is at least 1400 ° F., preferably up to 1600 ° F., and 1800 ° F.

Partially regenerated catalyst, which is almost free of hydrogen in residual carbon deposits on the catalyst, is attracted from the bottom of the bed 38 to be conveyed upwards through the lighter 52, so that in the upper, separated second catalyst regeneration zone 58 Drained to the high density fluid bed bottom of catalyst 54. Lift gas, such as compressed air, is loaded into the bottom inlet of riser 52 by a stem plug valve 60 of the pupil that includes flow control means (not shown).

The conditions in the second catalyst regeneration zone are manipulated in a manner well known in the art to achieve nearly complete carbon combustion removal from the catalyst that is not removed in the first regeneration zone. Thus, regenerated gas, such as gas enriched with air or oxygen, is loaded into bed 54 by tubing means 62 connected with air distributor ring 64. As shown in the figure, the vessel 58 in the second regeneration region has almost no exposed metallic inner material and is separated from the cyclone, so that the desired high temperature regeneration is achieved without introducing temperature problems associated with the structure. The second regeneration zone is always made from a refractory lined container or other suitable thermally stable material known in the art, wherein the high temperature regeneration of the catalyst is almost complete in the high density catalyst bed 56 to form carbon dioxide rich flue gas. The presence of sufficient oxygen to produce combustion of carbon monoxide and in the absence of hydrogen or vapor formed. Thus, temperature conditions and coral concentrations are not limited and may exceed 1600 ° F. and may reach 1800 ° F., or may reach temperatures necessary for sufficiently complete carbon combustion. However, the temperature is usually kept between 1300 ° F and 1600 ° F.

In this catalytic regeneration atmosphere, residual carbon deposits remaining on the supersolvent following the first temperature limited first regeneration zone are almost completely removed in the second non-limiting temperature regeneration zone. The temperature of the vessel 58 in the second regeneration zone is not specifically limited by the upper limit, but may be limited by the amount of carbon to be removed therein and the thermal equilibrium limitation of the catalytic decomposition-regeneration operation. If necessary, a means not shown in the second regeneration zone 58 is provided to allow the low temperature regenerator temperature for the purpose of controlling such thermal balance limitations by removing heat from the regenerator. Examples of preferred heat removal means include a controllable catalytic cooler as described in US Pat. Nos. 2, 970, 117 and 4, 064, 039 and the like. In this preferred means, some of the catalyst in the regenerator is drawn from its bottom outlet and passed downwardly out of the regenerator, for example with the air as a fluidized bed through an indirect water-cooled steam generator, rising to the top inlet of the regenerator. do. If desired, the cooled catalyst can optionally be reintroduced into the bottom inlet of the regenerator. Depending on the coke formation tendency of the heavy hydrocarbon feed to be treated, for example depending on the Conradson carbon residual of the feed, the cooler can be sized.

As described above, sufficient oxygen is loaded into the vessel 58 in an amount capable of combusting residual carbon on the catalyst, producing a relatively carbon dioxide rich flue gas with the presence of a small amount of carbon monoxide. The CO ₂ enriched flue gas thus generated is passed along with the entrained catalyst particles from the high density fluid catalyst bed 54 into a more dispersed catalyst phase, from which the flue gas is indicated by one of the signs 74 or It is attracted by one or more tubes 70, 72 connected to more cyclone separators. The catalyst particles separated from the hot flue gas in the cyclone are passed to the catalyst bed 54 in the second regeneration zone 58 by dippel means 76. CO ₂ enriched flue gas without the quantity and catalyst fines for assisting combustion of CO is one or more from cyclone 74 for use as described above in combination with the first regeneration zone flue gas. The tube 78 is recovered.

The regenerated catalyst particles in the hot zone 58 are attracted by refractories lined pipes 80 and 81 for individual passage to the integrated vessels 82 and 83, which are then flowed by the tubes 84 and 85. Pass through control valves V ₈₄ , V ₈₅ and into conduits 10, 12 that are connected to riser reactor 8 discussed above and a second riser reactor 108 to be discussed more fully later. . Aeration gas may be introduced into the bottom of the vessels 82, 83 by tubing means 86 connected with the discreetary ring in the vessel. The gaseous material attracted from the tops of the 82 and 83 by the tube means 88 is passed into the dispersed catalyst bed on top of the vessel 58.

Simultaneously with the heavy hydrocarbon feed cracking operation described above, the naphtha feed flow to be catalytically cracked such as light, medium or heavy direct current naphtha, together with the cracking naphtha selected if necessary, is fed to the tube means 14. Is introduced into the bottom of the second extended riser reactor 108, which passes through multiple flows in the loaded riser cross-section through a plurality of horizontally spaced feed injection nozzles 16. Such nozzles are preferably spray injection jet nozzles or similar to high energy injection nozzles of the type described above.

As in the first riser reactor 8, the hot, freshly regenerated catalyst is introduced into the bottom of the riser reactor 108 by tubing means 12, causing upward flow and in the riser reactor 108 cross-sectional area. Mixed with multiple hydrocarbon feed streams. This is done in sufficient quantity to form a hot evaporated mixture or suspension with the hydrocarbon feed. Also in the first riser reactor 8, steam, fuel, gas or other suitable gas can be introduced through the pipe means 2 into the feed injection nozzle to facilitate atomization and / or evaporation of the hydrocarbon feed, or As a medium for aeration, fluidization or dilution. Thus formed and passed through a hot suspension riser 108 comprising hydrocarbons, diluents, fluidized gas, etc., and suspended (fluidized) catalyst. The riser is operated independently of the first riser reactor 8 in such a way that it selectively catalytically decomposes the relatively low boiling naphtha with the light olefins and the desired product including high octane gasoline and gasoline precursors.

The purpose from naphtha feed is well known cracking conditions in the second riser reactor 108 which selectively produces cracking products. For example, heavy carbon laydown on a catalyst, i.e. coke build up or hydrocarbonaceous material (which can be freely acting by heavy feed residual oil, etc.) may be harmful to both sides. If possible, it is more detrimental to gasoline selectivity when decomposing relative low-boiling feeds such as direct current naphtha or heavy cracked naphtha, rather than decomposing relative high boiling feeds such as residual oil. Thus, the net benefit of gasoline selectivity is that low molecular weight feeds may undergo decomposition in a second riser reactor 108 independent of the first riser reactor 8 without heavy feed and sufficient coke laydown. By doing so. Heavy feeds also undergo decomposition to gasoline and gasoline precursors at lower selectivity than light hydrocarbon feeds. Thus, as previously mentioned, heavy in the first riser reactor 8 to control excessive coke build-up, generally to limit as much degradation as possible to the mono aromatic and di aromatic compounds and paraffinic side chains. It is advantageous to initially place the hydrocarbon feed component of at a reduced residence time and very high temperature, and simultaneously and independently, under the combined influence of variables such as longer residence time and higher catalyst to oil ratio. The rigidity of the naphtha feed decomposed in the operation of the riser reactor 108 of 2 is increased, thereby increasing the mixed zone outlet and catalyst zone inlet temperature in the presence of low carbon in the above mentioned catalytic effect. Furthermore, employing separate riser reactors 8,108 optimizes the desired feed conversion. Thus, it can be seen that the carbons in the dilution and catalytic effects described above are independent and can be treated in an advantageous manner in the process of the present invention in which the selectivity of the gasoline in the overall system is enhanced and air-conditioned.

Thus, according to the new arrangement and procedure of the inventive device shown above, it is possible to select the optimum operating conditions in the second riser reactor 108 which is sufficiently independent of the first riser reactor 8, which Conditions are particularly suitable for catalytic cracking naphtha feeds, providing increased recovery of desired high octane gasoline products and light olefins. On the other hand this simultaneously operates the first riser reactor under conditions to be mentioned later, which is good for optimal conversion of heavy, high-boiling grades to gasoline and light cycle oil boiling range materials.

It is also known that the increased catalytic conversion of direct and cracked naphtha is provided by the addition of high yields of light olefins such as butylene and polypropylene to products with increased octane number, which is an important petrochemical dimerization. ) And alkylated raw materials, and also the high temperature recombination of cracked FCC gasoline components are known to improve octane number. Thus, in addition to providing selective control of the optimum cracking conditions of a particular feed, the novel arrangement and process of the apparatus of the present invention provides a first preferred method for increased conversion and high temperature cracking of the naphtha feed to the desired product as mentioned above. And an extremely high decomposition temperature capability made possible by the use of a second catalyst regeneration zone.

As described above, the naphtha is preferably catalytically cracked in the second riser 108 in a state that includes a nominal stay time of 1 to 10 seconds and the following conditions. That is, feed preheating temperature of 220 ° F to 700 ° F, riser reactor mixing zone effluent temperature of 102 ° F to 1200 ° F, riser reactor catalyst zone inlet temperature of 980 ° F to 1200 ° F and riser reactor outflow temperature of 950 ° F to 1050 ° F, Such as riser pressure of 15 to 35 psig. The catalyst to oil ratio in the second riser reactor based on the total feed can range from 3 to 12 and the coke on the regenerated catalyst ranges from 0.1 to 0.5 weight percent.

The effluent from the second riser reactor 108, including the evaporated hydrocarbon-catalyst suspension comprising the product of catalytically cracked naphtha conversion, is drawn from the upper end of riser 108 at sign 26 as described above. One located in the top of the vessel 20 to pass through the outlet via initial separation in the suspension separation means indicated by the and / or to further separate the volatile hydrocarbons from the catalyst particles as described above. Or more cyclone separators 28. Separated evaporative hydrocarbons, diluents, gaseous materials for strips and the like can be attracted by the tube 90 for passage as a product recovery equipment and combination with materials from the decomposition operation in the riser reactor 8.

The spent catalyst separated by means 26 and cyclone 28 and subjected to decomposition in riser reactor 108 is integrated in catalyst bed 30, as described above in the first and second regeneration zones. Is played in a manner.

In the riser reactor (8,108) a mixture comprising the material from the hydrolyzed decomposition products and the separated evaporative hydrocarbons is passed to the bottom of the main fractionation type column (98) by means of a tube means (90) and a moving tube means (94). Attracted, wherein the intermediate of the product is classified as a fraction of the plurality of desired components. From the top of the column 98, the gaseous fraction can be drawn through the tubing means 100 to pass through the wet wetting compressor 102 and then through the tubing 104 to the gas separation plant 106. .

The light liquid fraction, including light C ₃ -C ₆ olefinic material and FCC naphtha, is also drawn from the top of column 98 via tubing means 107 to pass to gas separation plant 106. The liquid condensate boiling in the range of C ₃ -430 ° F. is drawn from the gas separation plant 106 by the tube means 110 and passed to the main fractional distillation column 98 as reflax to about 400 ° F.- Maintain the desired final boiling point of the naphtha product fraction in the range of 430 ° F.

The sand product produced in the gas separation plant 106 comprises a C ₃ / C ₄ light olefin LPG fraction, which is passed through the pipe section 11 and further treated with ethylene and propylene in a treatment means not shown, This also includes waste gas containing hard boiling materials attracted from pipe 112, light FCC gasoline products boiling at up to about 108 ° F., medium FCC gasoline products boiling in the range from 100 ° F. to about 310 ° F., and Heavy FCC gasoline and the like boiling in the range from 310 ° F. to about 430 ° F., which can generally be attracted from the tubing means 113.

The pump around the tubing means 114 connected to the top of the column 98 supplies at least a portion of the heavy FCC naphtha flow to feed injection nozzles of the second riser reactor 108 via the tubing means 4, 116, 14. 16), where the flow is combined with the hot regenerated catalyst introduced by the tube 12 to form a suspension in the manner described above. The heavy FCC naphtha is thus subjected to simultaneous catalytic cracking of the direct current and heavy FCC naphtha in the presence of a direct current naphtha feed introduced by the tube means 14 under optimal conditions selected to produce high octane gasoline and gasoline feeds. Are cycled and decomposed. In such an arrangement it is contemplated to decompose the heavy FCC naphtha recycle in riser 108 either alone or in combination with direct current naphtha as described above.

Heavy FCC naphtha can be passed, in whole or in part, to feed injection nozzles 6 of the first riser reactor 8 via tubing means 114, 4, where it is passed to tubing means 110. Combined with the hot recycled catalyst introduced thereby to form a suspension in the presence of a heavy hydrocarbon feed to achieve contact hydrocarbon cracking in combination with the heavy hydrocarbon cracking above and also to optimize the desired product distribution.

Further, in this arrangement of the invention, a direct current naphtha feed is supplied via a feed tube 14 to a tube 4 and subsequently to a spray nozzle 6 of the first riser reactor 8, thereby providing a tube 4. The cracking of heavy hydrocarbon feeds introduced by) and the catalytic cracking of direct current naphtha in combination are contemplated.

In addition, the process and apparatus of the present invention provides a lighter and lower boiling material than heavy FCC naphtha and is combined or solely contacted with recycled heavy FCC naphtha, direct current naphtha and / or heavy gas oil / residue hydrocarbon feeds. Consider disassembly. Such material comprises a selected FCC gasoline cut, which is drawn from gas plant 106 via tubing means 108 and 114 and subsequently fed to tubing means 4 and / or tubing means 14, It is introduced into feed nozzles 6, 16 of each of the first and second riser reactors for such catalytic cracking.

A portion of the heavy FCC naphtha flow may be passed through tubing means 114 to tubing means 160 as lean oil material for gas regeneration plant 106.

Light cycle gas oil (LCO) / distillate fraction comprising naphtha boiling range hydrocarbons is drawn from column (98) via tubing means (124), and the LCO / distillate fraction has an initial boiling point in the range of about 300 ° F. to about 430 ° F. And an end point of about 600 ° F. to 670 ° F.

Distillate fraction (not shown) may be further processed in a stripper vessel, in which the LCO / distillate fraction is stripped of the hard naphtha component from the fraction by contacting the vapor for stripping, followed by hydrotreatment or other Stripped LCO / distillate fractions are produced which can be passed through appropriate treatment means to convert to diesel mixtures. Stripped vapor comprising naphtha boiling range material may be passed from the stripper vessel to the main production inlet by means (not shown).

In the process and apparatus of the present invention, to optimize the desired product distribution, a portion of the LCO / distillate produced as described above is used in conjunction with the dihydrocarbon feed flow described above via pipe means 124 and other naphtha. There is a passage through tube 14 via tube means 124.

The circulating gas oil (HCO) fraction in non-distillation having an initial boiling range of about 600 ° F. to about 670 ° F. from the tube 98 at the midpoint thereof, lower than the LCO distillate fraction fraction, Induced via). Although not shown in the figure, at least a portion of the HCO flow may be passed through the tube 4 to be re-degraded in the riser reactor 8 in the manner presented herein.

From the bottom of column 98, slurry oil comprising non-distilled HCO boiling material is drawn through tubing means 132 at temperatures ranging from about 600 ° F to 700 ° F. A portion of the slurry oil is passed from the tube 132 through the waste heat steam generator 134, where the portion of the slurry oil is cooled to a temperature of about 450 ° F. From the waste heat steam generator 134, the cooled slurry oil flows to the bottom of the column 98 as additional reflux. A second portion of the slurry oil to be drawn and produced as such via the tube 136 flows as a product slurry.

It will be apparent to those skilled in the art that the process and apparatus of the present invention can be applied to any form of combination fluidization contact-regeneration process employing first and second (individual low and high temperature) catalytic regeneration zones. will be.

For example, as illustrated in US Pat. Nos. 4,601,814, 4,336,160 and 4,332,672, the tack stacking described in the embodiment of FIG. In addition to the stacked ＂regeneration zone, a“ side-by-side ”catalyst regeneration zone shape may be employed herein.

Claims (6)

In a fluidization catalyst-decomposition process comprising a first and second catalyst regeneration zones separated and decomposing a hydrocarbon feedstock or a vapor thereof as a decomposition catalyst, the catalyst is characterized in that the first regeneration zone flue is relatively rich in carbon monoxide. Regeneration of the first and second continuously by burning hydrocarbonaceous deposits on the catalyst in the presence of an oxygen-containing gas under conditions effective for producing a flue gas and a second regeneration zone flue gas enriched with relatively carbon dioxide. The regeneration continues in the zone, the temperature of the first regeneration zone ranges from 1100 ° F. to about 1300 ° F., and the temperature of the second regeneration zone ranges from 1300 ° F. to about 1800 ° F., and (a) a temperature of at least 1300 ° F., 5 First extended riser reaction in the presence of a regenerated cracking catalyst fed from the second catalyst regeneration zone, at a catalyst to oil ratio of 10 to 10 and a settling time of 1 to 4 seconds. Cracking the first hydrocarbon feed comprising gas oil and / or residual oil boiling range material, wherein coke is deposited on the catalyst in an amount of less than 1.2% by weight to give a heavy naphtha fraction ( evaporation of the first hydrocarbon feed comprising fractions, materials boiling higher than the heavy naphtha powder, ligand cycle oils, heavy cycle oils, and materials boiling higher than the heavy cycle oils, and the like. Obtaining a conversion product and (b) at the same time as the above step, regenerated cracking fed from the second catalyst regeneration zone at a temperature of at least 1300 ° F., a catalyst to oil ratio of 3 to 12 and a settling time of 1 to 5 seconds. A second hydrocarbon feed comprising virgin naphtha and / or medium and medium cracked naphtha boiling range materials in a second extended riser reactor in the presence of a catalyst And in this step coke is immersed on the catalyst in an amount of less than 0.5 weight percent, thereby producing a second hydrocarbon comprising light hydrocarbon material from light cycle oil material and gasoline boiling range material with high aromatic content and octane number. Obtaining an evaporative conversion product of the feed, and (c) passing and combining the evaporative conversion product from the first and second extended riser reactors in a conventional disengaging zone and entrained catalyst in this step. The particles are separated from the evaporative product and the combined conversion products are passed through a fractional distillation zone to ensure that at least gasoline boiling range fraction and light gaseous hydrocarbon fraction fraction, heavy naphtha boiling range fraction, slurry oil and high boiling fraction fraction are obtained. Medium cycle boiling range substance fraction to include and light cycle oil boiling range substance A method for improving the step of including the step of recovering. The method of claim 1, wherein at least a portion of the gasoline and / or heavy naphtha fraction is recycled and recomposed in a second riser reactor and / or a first riser reactor. The process of claim 2 wherein the gasoline and / or heavy naphtha fractions are re-decomposed in the presence of direct current naphtha to improve the octane ratio and aromatic content. The method of claim 1, wherein the first hydrocarbon feed comprises a heavy hydrocarbon feed, wherein the heavy hydrocarbon feed is at least 400 ° F. with at least 20 weight percent of its components boiling at 1000 ° F. or higher. The first hydrocarbon feed has at least 2 weight percent conradsor carbon boiling, and the second hydrocarbon feed is medium and / or heavy, including direct current naphtha boiling in the range of 10 ° F. to 392 ° F. and components boiling up to about 450 ° F. How to include naphtha. The hydrocarbon feed or its vapors are cracked in a fluidized state with micronized cracking catalyst to produce cracked catalyst particles and decomposition products with hydrocarbonaceous deposits, strip evaporative hydrocarbon products from the catalyst particles, and fouled them. The catalyst is transferred to the first regeneration zone where it is capable of removing almost all hydrocarbons associated with hydrocarbonaceous deposits on the catalyst at temperatures below about 1300 ° F. in the presence of an effective amount of pressure and coral content gas ranging from about 15 to 40 psig. By burning, the catalyst is partially regenerated to produce a first regeneration zone flue gas having a carbon monoxide content ranging from about 2 to about 80 volume percent, and then the partially regenerated catalyst is transferred to a second regeneration zone to contain coral. At a temperature in the range of about 1300 ° F. to 1800 ° F. in the presence of an effective amount of gas. In the fluidized catalytic cracking-regeneration process, combustion of almost all hydrocarbonaceous deposits remaining on the surface produces a second regeneration zone flue gas having a carbon monoxide content of less than about 1200 parts per million by volume of catalyst. (a) a first extended riser reactor in the presence of a regenerated cracking catalyst, fed from a second catalyst regeneration zone at a fill time of 1 to 4 seconds, a catalyst to oil ratio of 5 to 10, a temperature of at least 1300 ° F. Decomposing a first hydrocarbon feed comprising gas oil and / or residual oil boiling range material, in which step coke is deposited on the catalyst in an amount of less than 1.2 weight percent, such as heavy naphtha fraction and heavy naphtha fraction. A first hydrocarbon comprising a lower boiling material, light cycle oil, heavy cycle oil, and a substance that boils higher than the heavy cycle oil; Obtain the evaporative conversion product of the feed and (b) feed from the second catalyst regeneration zone at a temperature of at least 1300 ° F. with a hold time of 1 to 5 seconds, oil percentage in the catalyst of 3 to 12, and at the same time as the above steps A second hydrocarbon feed comprising a direct current naphtha, an intermediate cracked naphtha or a medium cracked naphtha, or mixtures thereof, boiling range materials, etc. in a second extended riser reactor in the presence of a regenerated cracking catalyst. In this step, coke is deposited on the catalyst in an amount of less than 0.4% by weight of a second hydrocarbon feed comprising light hydrocarbon material from the light cycle oil material and gasoline boiling range material with high aromatic content and octane number. Obtaining an evaporative conversion product, and (c) removing the evaporative conversion product from the first and second extended riser reactors in the normal separation process. Passing and combining in the disengaging zone, where the entrained solid particles are separated from the heavy production material and the combined conversion product is passed through a fractional distillation zone, at least gasoline boiling range material fraction and light gaseous hydrocarbon material fraction. Recovering the heavy cycle boiling range material and the ramped oil boiling range material fraction comprising heavy naphtha boiling range material fraction, slurry oil and high boiling material fraction. Fluidized catalytic cracking process for cracking hydrocarbon feedstocks into cracking catalysts, in the process of (a) contacting gaseous and / or residual oil boiling range materials, including fluidized beds of undifferentiated recycled catalyst particles, to produce a cracked product. And a first riser reactor producing an effluent comprising spent catalyst particles with hydrocarbonaceous deposits, (b) a fluidized bed of finely divided regenerated catalyst particles containing a direct current naphtha, intermediate cracked naphtha or medium cracked naphtha boiling range material or Contacting these mixtures with catalyst particles, thereby producing a second riser reactor that produces an exhaust comprising particles and decomposition products in a spent catalyst with hydrocarbonaceous deposits, and (c) effluent from the first and second riser reactors. A separation zone for receiving and separating the cracked product from the spent catalyst particles, and (d) a separation zone. A stripping zone which receives the spent catalyst particles from the strip and separates the evaporative hydrocarbon material from the spent catalyst in the presence of a stripping gas, (e) receives the spent catalyst particles from the strip zone, 15 Burns nearly all hydrogen associated with hydrocarbonaceous deposits on catalyst particles at temperatures ranging from about 1100 ° F. to about 1300 ° F. in the presence of pressures in the range of from 40 psig and effective amounts of carbon-containing gas; A first fluidized catalyst regeneration zone having a content of carbon monoxide, the first catalyst regeneration zone flue gas and a partially regenerated catalyst, the first fluidization catalyst regeneration zone having an inlet to accommodate the oxygen-containing gas required for fluidization and combustion, and (f) a first 10 to 40 psig in the presence of an effective amount of oxygen containing gas, containing partially regenerated catalyst from the catalyst regeneration zone Burn almost all of the hydrocarbonaceous deposits on the catalyst at pressure and in the temperature range of 1300 ° F. to 1800 ° F., and a fully regenerated catalyst having a carbon content of less than about 0.003 weight percent and a second having less than 1200 parts per million carbon monoxide. For regeneration and fluidization and combustion to produce a catalyst regeneration zone off-gas and to pass the fully regenerated catalyst through the first and second riser reactors, (a) and (b), respectively, for the contact of the hydrocarbon feedstock A second fluidized catalyst regeneration zone having an inlet to receive the required oxygen containing gas and (g) a cracked product from separation zone (c) and an evaporative hydrocarbon material from step (d) to receive the product fraction An apparatus including a fractional distillation zone to be recovered.

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