UA51609C2 - Method for catalytic reforming of hydrocarbons and a reactor system for catalytic reforming - Google Patents

Abstract

Disclosed is а method for reforming hydrocarbons comprising contacting the hydrocarbons with a catalyst in a reactor system (10, 20. 30) of improved resistance to carburization and metal dusting under conditions of low sulfur.

Description

Description of the invention

This patent is a partial continuation of US Patent No. 666,696 dated March 8, 1991, the content of which is incorporated herein by reference, and is related to US Application No. No. 802,821 (attorney's signature

MO 005950-316) and to the US application MO 803,215 (attorney's inscription MO 005950-333), which are simultaneously considered here and the contents of which are included herewith in the form of a link.

The present invention relates to improved methods of catalytic reforming, in particular catalytic reforming in low-sulfur, as well as low-sulfur and low-hydrogen conditions. In more detail, the invention relates to the discovery and resolution of problems arising in connection with the implementation of low-sulfur, as well as low-sulfur and low-hydrogen reforming processes.

Catalytic reforming is well known in the oil industry and includes the processing of oil fractions to improve the octane rating by producing aromatic compounds.

The most important reactions of hydrocarbons that take place during the reforming operation include reactions of dehydrogenation of cyclohexanes to aromatic compounds, dehydroisomerization of alkylcyclopentanes to aromatic compounds, and dehydrocyclization of acyclic hydrocarbons to aromatic compounds. Some other reactions are also carried out, including dealkylation of alkylbenzenes, isomerization of paraffins, and hydrocracking reactions, as a result of which light gaseous hydrocarbons such as methane, ethane, propane, and butane are formed. It is important to minimize hydrocracking reactions in the reforming process, as they reduce the output of gasoline boiling products and hydrogen.

Since there is a demand for high-octane gasoline, extensive research is being conducted, dedicated to the search for improved reforming catalysts and catalytic reforming processes.

Catalyst! necessary for successful reforming processes! have good selectivity. This means that they must be effective in production with a high yield of liquid products in the range of boiling gasolines containing a high concentration of aromatic hydrocarbons with a high octane number.

At the same time, the low output of light gaseous hydrocarbons must be beaten. Catalyst! duty! possess high activity to minimize excessively high temperatures for the production of products of a certain quality. It is also necessary for catalysts to either have good stability in order to preserve the characteristics of activity and selectivity during long periods of operation, or to have sufficient regeneration capacity, so that it is possible to allow their frequent regeneration without loss of performance characteristics.

Catalytic reforming is also an important process in the chemical industry. There is "-- a significantly increasing demand for aromatic hydrocarbons for use in the production of various chemical products, such as synthetic fibers, insecticides), adhesives, cleaners, plastics, synthetic rubbers, pharmaceutical products!, high-octane gasoline, product! perfumes, dry oils, ion-exchange resins and various other products, well known to specialists. "

Recently, an important technological improvement in catalytic reforming has appeared, which includes the use of highly porous zeolite catalysts. These catalysts), in addition, are characterized by the presence of alkaline or alkaline-earth metals and contain one or more MI metals! groups z» It was found that this type of catalyst mainly provides higher selectivity and longer duration of catalytic action than the previously used catalyst.

In the presence of selective catalysts with an acceptable life cycle, their successful commercial use seemed inevitable. Unfortunately, it was later discovered that the highly selective highly porous zeolite catalyst containing metal! E! group, is unusually susceptible to sulfur poisoning. See US Pat. No. 4,456,527.

According to this patent, the method of catalytic hydrocarbon reforming includes a stage

Reaction of a sulfur-sensitive zeolite reforming catalyst with a hydrocarbon, under conditions of 20 low content, less than about 100 pp, series, in a reactor system including a furnace containing a plurality of furnace tubes and a reforming reactor, including a substrate for a sulfur-sensitive catalyst.

In the end, it was discovered that for an effective solution to these problems! level of sulfur! in hydrocarbon sulfur should be ultra-low, preferably less than 100 parts per billion 29 (ppb), more preferably less than 50 ppb, to achieve acceptable stability and level

HF) catalyst activity.

After the discovery of the sulfur sensitivity associated with these new catalysts, and the determination of the necessity and acceptable levels of the amount of sulfur in the process, the possibility of successful commercial use of these catalysts again appeared; but only with the disappearance of other problems that appeared. 60 It was found that some highly porous zeolite catalysts are also unfavorably sensitive to the presence of lead under typical reaction conditions. In particular, it was found that water significantly accelerates the rate of deactivation of the catalyst.

It turned out that water sensitivity is a serious obstacle that is difficult to effectively overcome. Water is formed at the beginning of each process cycle when the catalyst is regenerated by hydrogen. Also, water can be formed during process disturbances, when water flows into the sulfur for the reforming plant, or when the sulfur is contaminated with oxygen-containing compounds. After all, the whites also developed! technologies for protection! of hydrogen catalysts.

Again, with the development of various low-sulfur and low-hydrogen systems for catalytic reforming, practical commercialization of the process using a highly selective, highly porous zeolite catalyst with extended catalyst lifetime seems possible. At the same time as a low-sulfur/low-hydrogen system! were initially effective, it was discovered that the reactor system must be stopped only after several weeks of operation." The reactor system at one inspected plant was regularly shut down after such short periods of operation! It was found that the 7/0 clogging was connected with coking. However, although coking inside the catalyst particles is a common problem in hydrocarbon processing, the scale and speed of coke plug formation on the outside of the catalyst particles associated with this particular system exceeded all expectations.

After a detailed analysis and study of coke plugs of low-sulfur reactor systems, it was surprisingly discovered that they contain metal particles and droplets; size! droplets lie within the range of up to /5 several microns. That observation led to a surprising understanding that there are new very serious problems that cannot be connected! with ordinary technologies of reforming, when the levels of sulfur and water! in the process are recognized as quite high. More specifically, it was discovered that there are problems related to the efficient and economical operation of the systems, as well as to the physical integrity of the equipment. It was also found that there are problems! arise as a result of low-sulfur conditions, and with some generalization, low water levels!

In the last forty years, the reactor system! of catalytic reforming were made of ordinary mild steel (for example, 24/54 St 1 Mo). He again showed that the systems can function successfully for approximately twenty years without significant loss of physical strength. However, the detection of metal particles and droplets in coke plugs ultimately leads to the study of physical characteristics of reactor systems. Surprisingly, symptomatic conditions of potentially severe physical degradation of the entire reactor system, including furnace tubes, i) pipelines, reactor walls and other details, such as a catalyst containing iron and metal grids in the reactor, were discovered. In the end, it was discovered that this problem is associated with excessive carburization of the steel, which increases its embrittlement, due to the injection of carbon into the metal, which is turned over in the process. Presumably, as a result of these processes, catastrophic physical destruction of reactor systems can occur! at

With ordinary reforming technologies, carbonization is not a problem; it was also not expected in modern low-sulfur/low-hydrogen systems. And it was assumed that it is possible to use the equipment for the ordinary process of reforming. As you can see, however, the presence of sulfur in ordinary systems effectively (87 z5) suppresses carburization. Somehow, in ordinary processes, the process of sulfur saturation also interferes with the carburization reaction. But in extremely low-sulfur systems, this internal protection no longer exists.

Fig. 1A shows a photomicrograph of the inner part (from the process side) of a mild steel furnace pipe of a commercial reforming plant. For about 19 years, the pipe was under general reformation conditions. "

This photo shows that the surface of the pipe remains essentially unchanged with the texture of the pipe, remaining normal after prolonged exposure to hydrocarbons at high temperatures (the black part of the photo is the background). ;" Fig. 18 shows a photomicrograph of part of a mild steel sample that was placed inside a low-sulfur/low-water demonstration reactor for only 13 weeks. The photo shows the destroyed surface of the sample (contrasting with the black background), from which the metal was sprayed. Dark streaks show carbonization of steel from the environment; the steel is carburized and embrittled more than 1 mm deep. - Of course, with the beginning of carbonization of physical systems! problems arise), connected with it. b Carburizing of steel walls leads to "metal sputtering" - removal of catalytically active particles and molten metal droplets as a result of metal cutting. o The formation of active metal particles provides additional sites for the formation of coke

to the system. Since the deactivation of catalysts by coking is a common problem of reforming, new significant sources of coke formation lead to new problems of coke plugs, which unnecessarily aggravate the problem. Indeed, it was established that moving particles are active! coke ov They infect the entire system with metastases of coking. Active metal particles actually induce the formation of coke on them and in any places where these particles collect in the system, leading to coke (F, plugs and hot regions of isothermal demethanization reactions. As a result, there is an uncontrollable and premature coke plugging of reactor systems), which can lead to shutdown of systems! within weeks of the start of work. 60 Thus, the task of the invention is to create a method of catalytic reforming of hydrocarbons in conditions of low sulfur content), which allowed to avoid several problems associated with low-sulfur processes, such as a short period! work

The second object of the invention is the creation of reactor systems! for catalytic reforming of hydrocarbons in conditions of low content of the series, which allowed to increase the period! work 65 The task is solved by the proposed method of catalytic hydrocarbon reforming, which includes the stage of interaction of a sulfur-sensitive zeolite reforming catalyst with a hydrocarbon, under conditions of low sulfur content, less than about 100 ppm, in a reactor system equipped with a set of furnace tubes and, in accordance with the invention , part of the reactor system! has resistance to carburization and metal spalling, at least not lower than stainless steel, under reforming conditions with a low sulfur content.

The proposed reactor system for catalytic reforming in conditions of low sulfur content, which includes a furnace containing many furnace tubes and a reforming reactor, including a substrate for a sulfur-sensitive catalyst and, in accordance with the invention, a part of the reactor system, contributes to the solution of these problems. for catalytic reforming, contacts a hydrocarbon 7/0 flow with a low sulfur content, and has increased resistance to carbonization.

The first aspect of the invention relates to a method of reforming hydrocarbons, which consists in contacting hydrocarbons with a reforming catalyst, preferably a highly porous zeolite catalyst, including an alkali and alkaline-earth metal and one or more MI metals! groups, in a reactor system that has resistance to carburization and metal spattering, which /5 is an improvement of ordinary reactor systems made of mild steel for low-sulfur and often low-sulfur and low-water conditions, the resistance during reforming should be such that embrittlement during carburizing less than about 2.5 mm/h, preferably less than 1.5 mm/h, more preferably less than mm/h, most preferably less than 0.1 mm/h.

Preemptive embrittlement to such limits will significantly reduce metal spalling and coking in the reactor system and will allow to increase the operating time of the installation.

Another aspect of the invention relates to a reactor system, including means for ensuring resistance to carburization and metal spalling, which are an improvement of the usual mild steel system in the method of reforming hydrocarbons using reforming catalysts, such as highly porous zeolite catalysts, including rare earth metal and one or more metals of the ME group, in low-sulfur conditions, the resistance should be such that embrittlement was less than about 2.5 mm/h, preferably less than 1.5 mm/h, more (8) preferably less than mm/h , most preferably smaller than 0.Tmm/h.

Thus, among other factors, the present invention is based on the discovery that in the low-sulfur and low-sulfur and low-water reforming process there are significant problems (33 of carburization, metal spraying and coking, problems! that do not have a place in to a significant degree in ordinary reforming processes where sulfur is present in significant quantities. This discovery led to intensive work and development of solutions to problems, solutions that are new for low-sulfur reforming processes and directions for the definition and selection of materials for low-sulfur systems reforming, ways to effectively use and apply additional materials (such as 5-serum) to reduce carburization, metal spraying and coking, to search for various modifications and configurations of the process and their combinations, which effectively solve the problem.

More specifically, the discovery led to the search, identification, and selection of materials stable in low-sulfur reforming systems, preferably for reactor walls, furnace tubes, and grids, that were not previously considered necessary in conventional reforming systems, such as certain alloys and stainless steels, " aluminized and chrome-plated material and some ceramic material. It was also found that other specific materials are used for electrogalvanic coated,

And cladding, painting, etc., can be effectively stable. These materials include copper, tin, and arsenic, antimony, brass, lead, bismuth, chromium, their intermetallic compounds and alloys, as well as silica and silicon-based coatings. In one preferred embodiment of the invention, a new and stable tin-containing paint is provided. c Further, the discovery led to the creation of some additional materials, here and further referred to as anti-carburizing and anti-coking materials), which are essentially sulfur-free, preferably completely sulfur-free and new for reforming. Such novel substances include organic tin compounds, organic antimony compounds, organic bismuth compounds, organic arsenic compounds and organic lead compounds. o Also, problems associated with low-sulfur reforming lead to the creation of some modifications and

There are process configurations that were previously not mandatory in general reforming. These include specific temperature control equipment, the use of superheated hydrogen between editors, more frequent catalyst regeneration, the use of taped temperature zones, the use of taped heaters and tubes, the use of superheated sulfur materials, and the use of larger diameter tubes and/or higher tube velocities. (F, For a better illustration of the essence of the invention, the following drawings are presented: ka FigLA - is a microphotograph of the inner part (facing the process) of a furnace pipe made of mild steel, taken from a commercial reforming installation, which has been in use for 19 years; kak br is also noted more

Fig. 18 is a photomicrograph of a part of a notched mild steel sample, which was placed inside the reactor of the low-sulfur/low-water demonstration plant for only 13 weeks.

Fig. 2 is an illustration of the reactor system! reforming, suitable for use in the present invention. 65 The metallurgical terms used in this description have their general metallurgical meaning, as established in the Metallurgical Encyclopedia (METAY NAMOVOOK) of the American Metallurgical Society. For example, "carbon steels" are those steels that do not have any alloying elements in excess of the established minimum amounts (other than manganese, silicon and copper in generally accepted quantities), which contain only random amounts of any elements, except for carbon, silicon, manganese, copper, sulfur and phosphorus. Carbon steels containing no more than 0.2595 carbon are called "mild steels". Alloyed steel is steel that contains a specified amount of alloying elements (other than carbon and the generally accepted amounts of manganese, copper, silicon, sulfur, and phosphorus) within the limits established for structural alloyed steels, which are added to effectively change mechanical or physical properties. Alloy steels contain less than 7/0. 109o chrome. Steels containing at least 10, preferably from 12 to 3095 chromium as the main alloying element are considered stainless.

The term "reactor system" used here implies the presence of at least one reforming reactor and corresponding heating means and pipelines. Fig.2 illustrates a typical reactor reforming system suitable for practical use of the present invention. It /5 can include several reforming reactors (10), (20) and (30). Each reactor contains a catalyst bed.

The system also includes several furnaces (11), (21) and (31); heat exchanger (12) and separator (13).

In the process of research related to the present invention, it was established that the above-mentioned problems! with low-sulfur reforming can be effectively resolved by selecting suitable materials for reactor systems! for contact with hydrocarbons during the process. A typical reactor 2O bistem reformer is constructed of mild steels or alloyed steels, such as typical chromium steels with minor carburization and spalling. For example, in the conditions of ordinary reforming 24;4 St-stne stove pipes! they can serve for twenty years. However, it was found that these steels become unsuitable under the conditions of low-sulfur reforming. They quickly, within one year, become brittle due to carbonization. For example, it was found that steel with 24" Sg and 1 Mo with Nnautlerazhivaetsya and embrittles at a rate greater than Tmm/h.

Moreover, it was found that materials considered in general metallurgical practice i) resistant to coking and carbonization are not necessarily stable in low-sulfur reforming conditions. For example, nickel-enriched alloys, such as YIIIncoloy 800 and 825 (Ipsoiou),

Inconel 600 (Ipsopei), Marcel and Haynes 230 (Mags! apa Neupez), are considered unacceptable, because they Ge! zo show an excessive ability to coke and spray.

However, 300 series stainless steels, preferably 304, 316, 321 and 347, are acceptable as materials for at least some parts of the reactor systems that come into contact with hydrocarbons in accordance with the present invention. It was found that they have resistance to carburization, greater than mild steels and nickel-enriched alloys. --

At first, it was believed that aluminized materials), such as those sold by the company AiYop Sogrogayop ("Alonized steel"), cannot provide adequate protection against carbonization of reactor systems! reforming considered in the invented process. However, since then, it has been discovered that coating the metal surfaces of the reforming reactor system with a thin aluminum or alumina film, or simply using alonized steels in the construction of the reactor, can provide "surfaces that are essentially resistant to carburization and metal spalling in the conditions of low-sulfur C) reforming . However, such a material! relatively expensive and, having resistance to carbonization and

And the spraying of metal has a tendency to crack formation and demonstrate a significant reduction in the tensile stress. Cracks expose the underlying base metal, leaving it unprotected against carburization and metal spalling in low-sulfur reforming conditions.

If for protection! aluminizing materials are used in steam carburizing, so the process is carried out at significantly higher temperatures than reforming; at those temperatures, carbonization should be expected. In previous processes of reforming, carbonization and metal spraying are simply not recognized as a problem. b Therefore, the second solution to problems! Carburizing and sputtering of metal includes applying thin 5p aluminum or alumina films to at least part of the metal surfaces of reactor systems or making them from aluminized materials. Indeed, metal surfaces, especially

He is sensitive to carburization and sputtering of metal, can be protected! in this way Such metal surfaces include, but are not limited to, reactor walls, furnace tubes, and furnace linings. 5B When aluminum or alumina films are used, it is preferable for the film to have a coefficient of thermal expansion close to that of the metal of the surface on which it is applied (Ф, film (such as mild steel), in order to resist thermal shocks and repeated temperature cycles that have place in the reforming process.This prevents cracking or flaking of the film, which can leave the underlying metal surface unprotected against carburization in a hydrocarbon environment.

In addition, the film must have a thermal conductivity close to or exceeding the thermal conductivity of metals commonly used in the construction of reactor reforming systems. Further, aluminum or alumina films are not suitable! to degrade in the reforming environment or in the oxidizing environment associated with catalyst regeneration; they also do not necessarily lead to the degradation of hydrocarbons in the reactor b5 system.

Suitable methods for applying aluminum or alumina films to metal surfaces, such as mild steel surfaces, are well-known methods! deposition

Preferred processes include the diffusion process! from the powder applied to the surface and from the vapor phase, such as the "Alonization" process, which is used on an industrial scale by the company

Aop Rgosezvipo, Ips., Terrytown, st. Pennsylvania.

The process of "Alonizing" is a high-temperature diffusion process, with the help of which aluminum is introduced into the surface of the processed metal, such as, for example, mild steel of commercial grades. In this process, metal (for example, mild steel) is placed in a retort and surrounded by a mixture of aluminum powders. The retort is then hermetically sealed and placed in a controlled atmosphere furnace. At elevated temperatures, aluminum diffuses deeply into the processed metal, forming an alloy as a result. After cooling the furnace, the material is removed from the retort, and the excess powder is removed. Then, if necessary, they can carry out more! straightening, cleaning, facing and other secondary operations. This process can make the processed ("alonized") metal resistant to carburization and metal spraying under the conditions of low-sulfur reforming in accordance with the invention.

Chromium or chromium oxide may also be applied to metal surfaces exposed to carbonization and metal sputtering, such as reactor walls, furnace linings, and furnace pipes. Applying thin films of chromium or chromium oxide can be useful for any system surface that shows signs of carburizing and sputtering of metal under conditions of low-sulfur reforming.

When a film of chromium or chromium oxide is applied, it is preferable that! chromium films or chromium oxides had a coefficient of thermal expansion close to that of the metal on which they are applied. In addition, chrome films or chrome oxides are required! you can! withstand heat shocks and repeated temperature cycles, which are common during reforming. This makes it possible to avoid cracking or flaking of chromium or chromium oxide films, which could lead to the contact of the adjacent surfaces with the metal with an environment that contributes to carburization. Next, chrome films or chrome oxides are required! have a thermal conductivity close to or exceeding the thermal conductivity of materials commonly used in i) reactor reforming systems (in particular, mild steels) in order to maintain effective heat transfer. Chrome films or chrome oxides are also not allowed! degrade in the reforming environment or in the oxidizing environment associated with catalyst regeneration; they are also not necessary! to induce degradation of hydrocarbons in the reactor system.

Suitable methods for applying films of chromium or chromium oxide on a surface, such as, for example, on the surface of mild steel, are the well-known deposition method. The preferred process includes "powder packing" and vapor phase diffusion, the so-called "chromization" process, used on a commercial scale by AiPow & Ipasevz, Inc., Wilmington, Pa. Delaware. --

The process of "chromization" is essentially diffusion from the vapor phase to apply chromium to the metal surface (analogous to the above-described process of "alonization"). The process involves bringing the metal into contact with chromium powder, followed by thermal diffusion. This effectively creates an alloy of chromium with the treated metal and makes the surface exceptionally resistant to carburization and spalling of the metal under the conditions of low-sulfur reforming. "

In some areas of reactor systems! local temperature during the reforming process can be extremely high (for example, 900 - 1250"; 1.87 - 17С, 07 - 32"Р). This is especially the case in the furnace pipes and in the catalyst bed, where the coke balls that are normally formed leak inside;" isothermal reaction of demethanation, causing local heating of the region. 300 series stainless steels exhibit some coking and spalling near 1000"P, although still preferred over mild steels and nickel-enriched alloys. Thus, 300 series stainless steels are not the most preferred material for use in the present invention, although they may be considered useful. - Chromium-enriched stainless steels, such as 446 and 430, are often more resistant to carburization than the Z00 series of stainless steels. However, these steels have undesirable properties in terms of heat resistance (they tend to embrittle. o Resistant material) , which are preferably 300 series stainless steels for

The elements used in this invention include copper, tin, arsenic, antimony, bismuth, chromium, brass, their intermetallic compounds and alloys! (for example, Cy-Zp alloys, Cy-5r alloys, stannium, antimonide, bismuthide, etc.) Steels and even nickel-enriched alloys containing these metals) can also show a decrease in carburization. In the preferred embodiment of the invention, this material! are used in the form of electro-deposited coatings, plating, painting (for example, oxide (F, paints) or other coatings of the main structural material. This is the main advantage, since it is possible to still use the main structural material, but with a surface that is in contact with hydrocarbons, processed in an appropriate manner. Of these materials, tin is the most preferable, since it reacts with the surface, providing a coating that has excellent resistance to carburization at higher temperatures and which is resistant to peeling and flaking of the coating. However, it can be considered that tin-containing layer can be as thick as 1/10 of a micrometer and still prevent carbonization. 65 In practice, it is preferred that these stable materials be applied in a form similar to paint (hereafter simply ``paint'') on new or operating reactor systems." Such paints can will be crucified applied with a brush or roller, etc. on the surface of reactor systems!, such as mild steel or stainless steel. It is most preferable that such paints are tin-containing paints capable of decomposing and reacting, reducing to reactive tin and forming tin. metals (for example, iron stannide or nickel-iron stannide) when heated in a reducing atmosphere.

Most preferably, the above-mentioned paint contained at least four components (or their functional equivalents): (i) a hydrogen-decomposable tin compound, (ii) a solvent system, (ii) a terminally separated metallic tin and (ii) tin oxide as a reducible spongy / 7/0 dispersing / binding agent. The paint must contain a finally separated solid substance to minimize sedimentation and must not contain non-reactive materials that will prevent the reaction of the reactive tin with the surface of the reactor systems!.

Tin octonoate is particularly useful as a tin compound decomposable by hydrogen.

The commercial version of this compound is quite available, and it partially hardens on the surface of the steel, /5 forming a gum-like layer; the layer does not crack and/or burn. This property is necessary for any coatings used in this context, since a situation is possible when the material with the coating will be stored for several months before its hydrogen treatment. Also, if some parts of the systems! coating before final assembly, the coating must be chip-resistant during installation. As noted above, tin octonoate is commercially available. It has a moderate cost, and it decomposes, forming a smooth layer of reactive tin, which forms iron stannide in a hydrogen atmosphere at a temperature of about 600".

However, tin octonoate should not be used in paint by itself. It is not viscous enough.

Even when the solvent evaporates from the paint, the remaining liquid will accumulate and run off the covered surface. In practice, for example, if such paint is used to cover a horizontal furnace with a pipe, it will collect in the lower part of the pipes, forming a puddle.

Component(s) - spongy / dispersing / binding agent from tin oxide is a porous and) tin-containing compound, which is able to make a spongy metal-organic compound of tin, and, in addition, it can also be reduced to active tin in a reducing atmosphere. In addition, tin oxide can be passed through a colploid mill to produce very fine particles, which slows down rapid sedimentation. The addition of tin oxide creates a paint that becomes solid when dried and does not flow when applied. at

In contrast to typical paint thickeners, the component (im) is selected in such a way that it becomes a reactive part of the coating during restoration. It is not inert, like forming silica - a typical paint thickener, which after processing should leave a non-reactive surface coating yu

The final separated metallic tin, component (ii), is added to insure that metallic tin is available for reaction with the coated surface at temperatures as low as possible, even in a non-reducing atmosphere. The size of tin particles is preferably equal to one to five microns, which provides excellent coverage of the surface to be covered with metallic tin. "Non-restorative conditions can occur during the drying process of the paint and during welding of the joints 7-3) with pipelines. The presence of metallic tin gives confidence that even when part of the coating is not completely restored, metallic tin will be present in the coating, which will be;" to react and form the desired layer of stannides.

The solvent must be non-toxic and effective enough to make the paint sprayable and spreadable if necessary. The melt must evaporate quickly and have the properties of a solvent compatible with the hydrogen-decomposable tin compound. Isopropyl alcohol is most preferred, although hexane and pentane can be used if necessary. Acetone, however, leads to the precipitation of tin-organic compounds. b In one of the embodiments of the invention, it is possible to use tin paint consisting of a 20 percent 5% solution of "Tin Ten-Tsem" (tin octanoate in octanoic acid), tin oxide, tin metal powder, and isopropyl alcohol.

Ge Tin paints can be applied in many different ways. For example, furnace tubes of reactor systems! can be painted individually or in modules. The reforming reactor system according to the present invention can contain a different number of furnace tube modules (for example, two to 24 furnace tube modules) of the corresponding length, height and width! (for example, about 10 feet long, about 4 feet wide, and about 40 feet high!; 1 foot is 30.48cm). Each typical module includes two (F) heads of appropriate diameter, preferably about 2 feet in diameter, which are connected by four to ten O-shaped pipes of appropriate length (for example, about 42 feet long). Then the entire surface area to be beaten is painted in modules, can vary widely, for example, in one embodiment of the invention, it was about 16,500 K2 (sq. ft.).

Painting modules, rather than individual pipes, can have an advantage in at least four respects: (i) painting modules, rather than individual pipes, will help to avoid thermal destruction of tin paint, since the component! modules routinely undergo heat treatment at extremely high temperatures during their production; (ii) painting of modules can probably be done faster and less expensive than painting of individual pipes; (ii) the coloring of the modules should be more effective in the production process according to the schedule; and (im) painting of modules should allow painting of weld seams.

However, painting the modules may not allow you to completely cover the pipes! paint, as it can be done by painting pipes individually. If the coverage is unsatisfactory, then trumpet! can be painted individually.

It is preferable that! paint was applied by spraying in pipes and heads. You need to use enough paint to! cover the pipes completely! and heads. After painting the module, it should be left to dry for 24 hours, after which it should be purged with a slow flow of heated nitrogen (for example, 150"E for 24 hours). After that, preferably, a second layer of paint should be applied and also dried using the procedures described above After applying the paint, the module should preferably be 7/0 maintained under a weak nitrogen pressure and should not be exposed to temperatures exceeding 200"E before its installation, it should also not be exposed to water, excluding the hydrotested process.

In the present invention, iron-containing reactive paints can also be useful. Such iron-containing reactive paints will preferably contain various tin compounds to which iron is added in an amount up to one-third of the Ee/5n ratio by weight.

Iron can be added, for example, in the form of He2O3. The addition of iron to tin-containing paints should have remarkable advantages; in particular, () it should promote the reaction of the paint with the formation of iron stannides, acting as a flux; (it) it should dilute the concentration of nickel in the stannite layers, providing at the same time a higher protection against coking, and (ii) it should lead to changes in the paint itself, ensuring the formation of iron stannites, which provide 2o protection against coking, even if the underlying surface is not reacted quite well.

Other means to prevent carburization, coking, and atomization of metal in a low-sulfur reactor system are the application of a metallic coating or surface plating of chromium-enriched steels contained in the reactor system. That is, the metal coating or plating can consist of tin, antimony, vistum or arsenic. Tin is especially preferred. These coatings or cladding can be applied by various methods, including electroplating, vapor deposition, immersion of chrome-enriched steel in a bath with i) molten metal.

It was discovered that in reforming reactor systems, in which carburization, coking, and metal spraying are a particular problem), covering chromium-enriched or nickel-containing steels with a layer of tin actually creates a double protective layer. As a result, an internal chromium-enriched layer is formed, which is resistant to carburization, coking, and metal spalling. This is due to the fact that when chromium-enriched tin-coated steel is exposed to typical reforming temperatures of around 1200 P, tin reacts with the steel to form iron-nickel stannites. At the same time, nickel is predominantly leached from the surface of the steel, leaving a layer of enriched In some situations, it may be desirable to remove a layer of iron-nickel stannides from the surface of stainless steels exposed to the environment!

For example, it was discovered that when a layer of plating tin is applied to the surface of stainless steel type 304 and heated to temperatures of about 1200 "P, the result is a layer of chrome-enriched steel containing about 1775 chromium and virtually no nickel, which is comparable to stainless 7) with 430 type steel.

When applied with a tin metal coating or plated with chrome-enriched steel, it can;" if desired, change the thickness of the metal coating or the cladding layer to achieve the desired resistance against carburization, coking and sputtering of the metal. This can be done, for example, by adjusting the time interval during which chromium-enriched steel is immersed in a bath of molten tin. This will also affect the thickness of the resulting chromium-enriched steel layer. It may also be desirable to change the processing temperature or to change the composition of the chrome-enriched steel on which the coating is applied, in order to control the concentration of chromium in the chromium-enriched steel layer.

In addition, it was discovered that tin-coated steel can be even more protected! This is about carbonization, metal spraying and coking by means of additional processing, which includes

The application of a thin oxide coating is preferably chromium oxide, such as Cg»Oz. So the coating should be thin, a few micrometers thick. Applying such a layer of chromium oxide will protect steels coated with both tin and aluminum, such as "alonized" steels, in low-sulfur reforming conditions.

A layer of chromium oxide can be applied by various methods, including the application of chromate or (F, dichromate paint, which is followed by a reduction process; steam treatment of chromium-organic compounds; or the application of a film of metallic chromium, which is followed by oxidation of the resulting chrome-plated steel. 60 Msptaniya of steels with a layer of tin applied by the electrogalvanic method, which for a long period of time were placed in low-sulfur reforming conditions, showed that when a layer of chromium oxide is applied to the surface of the stannium layer or under the stannium layer, this layer of chromium oxide does not cause deterioration of the stannium layer, however, it contributes to an increase in the resistance of steel to carburization, coking, and metal spraying. Accordingly, the application of a layer of chromium oxide on steel 65 P coated with either tin or aluminum will lead to a further increase in the resistance of steel to carburization and coking under low-sulfur reforming conditions. ess of additional processing is especially applicable for processing steels covered with tin or aluminum, which need to be repaired after a long exposure in the conditions of low-sulfur reforming.

Further, it was discovered that aluminized, for example, "alonized" steels, which are resistant to carburization under the conditions of active or low-sulfur reforming, can be made more stable by additional processing of aluminum-coated steel in the form of applying a layer of tin.

This operation gives steel that is more resistant to carburization, since there are cumulative effects! resistance to carburization obtained by both aluminum coating and chromium coating. This additional treatment brings an additional benefit in that it heals 70 or more defects or cracks in the aluminum, for example, "alonized" coating. Also, such additional processing should lead to a lower cost, since a thinner aluminum coating can be applied to the surface of the steel, which will then be further processed by applying tin. In addition, this treatment will protect the underlying layer of steel exposed to bends of aluminized steel, which may introduce cracks into the aluminum layer and expose steel /5 to carburization under reforming conditions. Thus, the additional treatment process can prevent the formation of coke on the surfaces of treated steels, as well as prevent the formation of coke that occurs at the bottom of cracks that appear on aluminized, but not additionally tin-coated, steels.

My studies showed that on samples of alonized steels, painted on one side! with tin, the deposition of black coke is observed only on the untreated side under the conditions of low-sulfur reforming. The coke that forms on the aluminized surface is benign coke that occurs on cracks in the places of oxidized aluminum. It is not able to induce additional coke deposition. Accordingly, additional processing by applying a tin coating to aluminized steel can ensure further minimization of the problems of carburization, coking, and sputtering of metal in a reactor system operating under reforming conditions in accordance with the invention. and)

Without wishing to be limited by theory, it can be considered that the suitability of various materials for the present invention can be selected and classified according to their response to the carbonizing atmosphere.

For example, iron, cobalt, and nickel form relatively unstable carbides, which will subsequently be carbonized, coked, and pulverized. Such elements as chromium, niobium, vanadium, tungsten, molybdenum, tantalum and zirconium will form stable carbides, which are more resistant to carburization, coking and spraying. Such elements as tin, antimony, and bismuth do not form carbides or coke. These elements can form stable compounds with many metals, such as iron, nickel, and copper under reforming conditions. c5 fusible compounds of lead, mercury, arsenic, germanium, indium, tellurium, selenium, thallium, sulfur, and oxygen are also considered stable. The latter category of materials includes such elements as silver, copper, gold, platinum, and refractory oxides such as silica and alumina. These materials are stable and do not form carbides or react with other metals in the carburizing environment under reforming conditions.

As discussed above, the selection of suitable metals resistant to carburization and metal sputtering, and their use as coating materials for metal surfaces in the reactor system is one of the means of solving the problems of metal carburization and sputtering. However, carburizing and spraying of metal can be predominant for a wide class of metals, and ;" resistance to carburizing metal! may be more expensive or rare compared to common materials (for example, mild steels) used in the construction of reactor reforming systems. Accordingly, it may be desirable to use ceramic materials in the reactor system of the invention, which do not form carbides in typical conditions of reforming and therefore are not susceptible to them! to carburization, for at least part of the metal surfaces of reactor systems! reforming - For example, at least part of the furnace pipes or furnace lining or both can damage structures made of ceramic materials.

When choosing ceramic materials for use in the present invention, it is preferable that the ceramic material has a thermal conductivity approximately equal to or greater than

Thermal conductivity of materials commonly used in the construction of reforming reactor systems.

In addition, ceramic materials must have sufficient structural strength at temperatures that occur inside reforming reactor systems. Next, ceramic material! in DdOlLzhzhnNh batteries capable of withstanding thermal shocks and repeated temperature cycling that may occur during operation! reactor system". When ceramic materials (F) are used for the construction of the furnace lining, the ceramic materials must have a coefficient of thermal expansion close to that of the metal of the outer surface, with which the lining is in close contact. This will avoid undesirable stresses in the joints during temperature cycling , which occurs when the installation is turned on and off. In addition, the ceramic surface should not be susceptible to degradation in a hydrocarbon environment or in an oxidizing atmosphere, which occurs during the catalyst regeneration process. The selected ceramic material should also not contribute to the degradation of hydrocarbons in the reactor system.

Suitable ceramic materials! include, but are not limited to such materials as carbide 65 Kkremnia, oxide! silicon, nitride! silicon and aluminum nitrides. Among those materials are silicon carbide and nitride! silicon are especially preferred, as they proved to be able to provide full protection of reactor systems! in the conditions of low-sulfur reforming.

At least part of the metal surfaces in the reactor system may also be covered with a film of silicon or silica. In particular, metal surfaces that can be covered,

They include, but are not limited to, reactor walls, furnace tubes, and furnace lining. However, any metal surface in the reactor system that shows signs of carbonization and spalling of the metal under the conditions of low-sulfur reforming will benefit from the application of a thin silicon or silica film.

7/0 can be used to apply silicon or siliceous film coatings on metal surfaces! ordinary method. Silica or silicon can be applied by the electrogalvanic method and by the method of chemical deposition from the vapor phase of alkoxysilane in the flow of the carrier gas.

It is preferable that silicon or siliceous films have a coefficient of thermal expansion close to that of the metal surface on which they are applied. In addition, silicon or silica film must! be capable of withstanding thermal shocks and repeated /5 temperature cycling that occur during the reforming process. This makes it possible to avoid cracking or flaking of the silicon or silica film and potential exposure of the underlying metal surface in the carbonization-inducing hydrocarbon environment. Also, the silica or silicon film must have a thermal conductivity approximately equal to or higher than the thermal conductivity of metals commonly used in reforming reactor systems, so as to maintain effective heat transfer. The film of silicon or silica should also not degrade in the reforming environment or in the oxidizing environment associated with catalyst regeneration. It should also not cause degradation of the hydrocarbons themselves.

Because different areas of reactor systems! inventions (for example, different areas in the furnace) can be exposed to temperatures in a wide range, it is necessary to select materials so that materials that provide the best resistance to carbonization are used in those areas of the system that are exposed to the highest temperatures. and)

In connection with the selection of materials, it was found that surface oxidation of metals MI! groups, such as iron, nickel and cobalt, are recognized as more active in a mixture of coking and carburizing than their non-oxidized duplicates. For example, it was found that air-fired samples of 347 stainless steel were significantly more active than non-oxidized samples of the same steel. It is thought that this is caused by the re-reduction of oxidized steel, resulting in the formation of very fine-grained iron and/or nickel. Such metals are the most active for carburizing and coking. In this way, it is desirable to avoid the use of those materials as much as possible in the processes of oxidative regeneration, which are typically used in catalytic reforming. However, it was found that an air-fired 300 series tin-coated stainless steel can provide the same resistance to coking and carburization as an unfired sample of the same tin-coated 300 series stainless steel.

Moreover, it has been estimated that oxidation will be a problem in systems where sulfur sensitivity of the catalyst is not concerned and where sulfur is used for passivation of metal surfaces. If the levels of sulfur in such systems ever become insufficient, the sulphide 7-3) from metals, which forms on metal surfaces after oxidation and restoration of duties! lead to fine-grained metal. This metal must be very sensitive to carburization and;" coking Potentially, it can cause a catastrophic failure of metallurgy or a major coking of the system.

As noted above, excessively high temperatures can occur in the area of the catalytic bed, since the isothermal demethanation reactions inside the coke balls cause locally hot areas. These hot spots are also a problem in general reactor reforming systems (as well as in other areas of chemical and petrochemical technologies). b For example, it was observed that the grids of the central pipes of the reformer are depleted and holes are formed in them; in the final account, that is, it leads to migration of the catalyst. In ordinary reforming processes, the temperature inside the coke balls in the process of formation and nucleation is apparently high enough that! surpass

The ability of sulfur in the process to suppress coking, carbonization and atomization. Metal grids are subsequently carbonized and become more sensitive to depletion by intergranular oxidation (one of the types of corrosion) during the regeneration process. The holes in the nets increase in size and form HOLES.

Thus, the ideas of the present invention are applied! also in ordinary reforming, as well as in other fields (F, areas of chemical and petrochemical technologies. For example, the above-mentioned electrogalvanic deposition, plating and coating can be used when a network of central pipes is made to avoid the development of unnecessary holes and migration of the catalyst. 60 In addition , since the objects described here can be used to control carburization, coking and sputtering of metal at excessively high temperatures, they can be used in cracking furnaces operating at temperatures from 1400 to 1700 degrees. For example, it is possible to control the wear of steel that occurs in cracking furnaces operating at such temperatures, by applying various metal coatings. These metal coatings can be applied by immersion in a 65 V melt, electrodeposition and painting. Painting is the most preferred.

For example, an antimony coating applied to steel based on iron protects the steel from carburization, coking, and metal spalling in the described cracking conditions. In fact, the antimony paint applied to the iron base of the steel will provide protection against carburization, coking and metal spattering at 1600 "Р.

Bismuth coating applied to a nickel-enriched steel alloy! (for example, IMSOMEI 600), can protect steel from carburization, coking and metal spalling in cracking conditions. This has been demonstrated at temperatures up to 1600 degrees.

Bismuth coatings can also be applied to the iron base of steel and can provide protection against carburization, metal spalling and coking in cracking conditions. It is also possible to use a metal coating, which is a combination of bismuth and antimony! and/or tin.

Returning again to low-sulfur reforming, it can be said that other methods can also be used to solve the problems posed by the present invention. They can be used together with the selection of suitable materials for reactor systems! or they can be used by themselves. A preferred method of additional methods is the addition of non-sulfur anti-carburizing, anti-coking substance(s) to process 7/5. These substances can be added continuously during the process and serve to interact with the surfaces of the reactor system, which are in contact with hydrocarbons, or they can be used as a preliminary treatment of the reactor system.

Not wanting to be limited by theory, we assume that these substances interact with the surfaces of the reactor systems! by decomposition and corrosion of the surface with the formation of iron and/or nickel intermetallic compounds, such as stannide, antimonide, bismuthide, plumbide, arsenide, etc.

Such intermetallic compounds are resistant to carbonization, coking and spalling and can protect the underlying metals.

It is also believed that intermetallic compounds are more stable than sulfides of metals, which are formed in systems when H 25 is used for passivation of metals. These compounds are not reduced by hydrogen, like metal sulfides. As a result, they leave the system with a lower i) probability than metal sulfide. Therefore, continuous addition of carburizing suppressors together with sulfur can be minimized.

Preferred non-sulfur anti-carburizing and anti-coking agents include a number of organometallic compounds such as organotin compounds, organoantimony compounds, organobismuth compounds, organoarsenic compounds and organolead compounds. Suitable organolead compounds include tetraethyl and tetramethyl lead. "at

Organotin compounds, such as tetrabutyltin and tetramethyltin hydride, are especially preferred. --

Additional special organometallic compounds include bismuth neodecanoate, chromium octoate, copper naphthenate, manganese carboxylate, palladium neodecanoate, silver neodecanoate, tetrabutylgermanium, tributylantimony, triphenylantimony, triphenylarsenic, and zirconium octoate.

It is not critical how and where the substances will be introduced into the reactor system, so it will depend primarily on the technical characteristics of the specific process. For example, they can be added "continuously or intermittently together with gray." However, the addition of these substances to sulfur is not preferable, since they will tend to accumulate in the initial parts of the reactor system. They will not be able to provide the required protection in;" other parts of reactor systems!.

It is preferable that these substances provide coverage before construction, before the start of work or installation (i.e. in the existing system). When IP-wash is added, this should be done immediately after regeneration from the catalyst. A very thin coating may be applied. For example, it can be considered that when tin-organic compounds are used, a 0.1-micron-thick coating of iron stannide can be effective. - The preferred method of applying substances to the existing or new surfaces of the reactor or to the new or existing furnace tubes is the decomposition of metal-organic compounds in a hydrogen 5° atmosphere at temperatures of about 900 "R. For tin-organic compounds, for example, this procedure gives a reactive metallic tin on the surface of the pipes.At those temperatures, tin will continue to form

It reacts with the surface of the metal and passivates it.

Optimum temperatures! applications will depend on the specific metal-organic compound or mixture of compounds, if it is desired to obtain alloys. A typical application procedure is that the excess metal-organic substance that creates the coating is fed into the pipe! in a high-speed flow of hydrogen, so as to carry the covering substance through the system in a suspended state. The flow rate (F) can then be reduced to allow the metallic suspension to coat and react with the furnace tubes or reactor surface. An alternative procedure is that the compound can be introduced into the system as a vapor, which decomposes and reacts with heated pipe walls or reactor boron in a reducing atmosphere.

As discussed above, reactor systems! reforming, susceptible to carbonization, metal spraying and coking, can be treated by applying a decomposable coating containing a decomposable metal-organic tin compound to the most susceptible surface of the reactor system! to carbonization. This approach is especially good for use in furnaces with 65 controlled temperature.

However, such control is not always carried out. There are "hot spots" that develop in the reactor system, especially in furnace tubes, where the metal-organic compound can decompose and form deposits. Therefore, the second aspect of the invention consists in the created process in which such deposits are removed in the reactor system of reforming, where temperatures! are not fully controlled and where are the regions of high-temperature heat spots.

Such a process includes preliminary heating of the entire reactor system! to temperatures from 750 to 1150, preferably from 900 to 1100, and most preferably about 1050", heated by a hydrogen gas stream. After preliminary heating, more is introduced into the preheated reactor system

A gas stream containing a vapor of a metal-organic compound of tin and hydrogen at 7/0 temperatures from 400 to 800, preferably from 500 to 700, and most preferably about 550". This gas mixture is introduced upstream and can provide a "wave" of decomposition, which passes through the entire reactor system.

In essence, this process works because heated hydrogen gas produces a uniformly heated surface, which will decompose the colder metal-organic gas when it passes in the form of /5 Waves through the reactor system. A colder gas containing a metal-organic compound of tin will decompose on a hot surface and form a coating on it. Vapors of metal-organic tin will continue to move along the current in the form of waves and process the heated surface of the reactor systems. Therefore, the entire reactor system can be uniformly coated with a metal-organic tin compound. It may also be desirable to perform several such temperature cycles of heating and cooling in order to guarantee a uniform coating of the entire reactor/system with a metal-organic tin compound.

During the operation of the reforming reactor system in accordance with the present invention, crude oil is converted with the formation of aromatic compounds. Petroleum sulfur is light hydrocarbons, preferably heated in the range from 70°C to 450°C, more preferably from 100 to 100°C. Petroleum sulfur contains aliphatic or paraffinic hydrocarbons. These aliphatic compounds are converted, at least partially, into aromatic compounds in the system reaction zone! reforming

In the "low-sulfur" system of the invention, the sulfur will preferably contain less than 10 Orr of sulfur, more preferably less than 5 Orr of sulfur. If necessary, to remove small excesses of the series (33 zr. You can use the absorption block of the series!.

Preferred conditions of the reforming process include a temperature between 700 and 1050"P, more preferably between 850 and 1025"E; and pressure between 0 and 400 herds, more preferably between 15 and 150 herds; hydrogen recycling rate sufficient to obtain a molar ratio of hydrogen to hydrocarbons for sulfur in the reforming reaction zone between 0.1 and 20, more preferably between 0.5 and 10; -- c5 the hourly spatial velocity of the liquid for hydrocarbon sulfur through the reforming catalyst is between 0.1 and 10, more preferably between b.5 and 5.

In order to reach the appropriate temperatures of the reformer, it is often necessary to heat the furnace tubes! to high temperatures. Temperatures! often lie in the range from 600 to 1800"P, usually from 850 to 1250"E, and most often from 900 to 1200"BE.

As noted above, it was found that there was a problem! carburizing, coking, and atomization of metal in pt") with low-sulfur systems in connection with local processes that occur at excessively high temperatures in reactor systems, and are recognized as particularly significant in furnace tubes of systems), which;" are characterized by especially high temperatures. In the general method of reforming, where there are significant levels of the series, typical temperatures! the surfaces of the furnace tubes reach 1175"E at the end of the run. However, excessive carburization, coking, and metal spattering are not observed. In low-sulfur systems, however, it was found that excessive and rapid carburization, coking, and metal spattering occur at Stimo steels at temperatures above 950°C and stainless steels at temperatures above 10257Р. b Correspondingly, the second aspect of the invention is lowering the temperature of metal surfaces inside furnace pipes, feed lines and/or reactor systems! reforming below the above-mentioned levels. For example, temperatures can be measured using thermocouples installed in

in different locations of the reactor system". In the case of furnace tubes, thermocouples! can be installed! on their outer walls, preferably in the hottest points of the furnace (generally near the pipe outlet). If necessary to maintain temperatures! at the desired level, you can enter an adjustment during the process.

There are also other ways! will reduce the effect of undesirably high temperatures on the surface (F, system!i. For example, heat transfer areas can be made using stable (and generally more expensive) pipes near the final stage, where temperatures are generally the highest.

In addition, superheated hydrogen can be added between the reactors of the reforming system. It is also possible to use a higher catalyst charge. In addition, it is possible to regenerate the catalyst more often. In the case of catalyst regeneration, it is best carried out using a moving bed process, when the catalyst is extracted from the final bed, regenerated and loaded into the first bed.

Carburization and metal spraying can also be minimized in the low-sulfur reforming reactor system considered in the invention using some other new 65 equipment configurations and process flow conditions. For example, the reactor system can be designed with taped heaters and/or pipes. In other words, heaters or pipe,

which are in the most extreme temperature conditions in the reactor system, can be constructed from materials that are more resistant to carburization than the material commonly used in the construction of reactor systems! reforming, with such materials as described above. Heaters or pipes), which are not in conditions of extreme temperatures, can continue to be constructed from ordinary materials.

With the use of such ad hoc construction of reactor systems, it becomes possible to reduce the total cost of the systems! (since materials resistant to carburization are generally more expensive than ordinary materials), while ensuring sufficient resistance of the reactor system to carburization and metal spalling in low-sulfur reforming conditions.

In addition, it should ensure the re-equipment of the existing reforming reactor systems in order to make them resistant to carburization and metal sputtering in low-sulfur working conditions!; since post-tap construction allows to replace or modify smaller parts of the reactor system.

The reactor system can also work with at least two temperature zones; at least one with higher and one with lower temperatures. This approach is based on the observation that metal sputtering has a temperature maximum and minimum, above and below which sputtering is minimized. Therefore, the term "higher" temperatures means that the temperatures are higher than those commonly used in reforming reactor systems, and higher than the maximum temperature of spraying. The term "lower" temperatures! means that the temperature is equal to or close to those temperatures at which the reforming process is generally carried out, and below those temperatures at which metal spalling becomes a problem.

The operation of different parts of the reactor system in different temperature zones should reduce metal spattering compared to a reactor system operating at temperatures conducive to metal spattering. Other advantages of such designs include improved heat transfer efficiency and the ability to reduce the size of the equipment, since some parts of the systems i) operate at higher temperatures. However, the operation of some parts of the reactor systems! at levels above and below those that contribute to metal spraying, it will only be minimized, but it will not allow to completely avoid the temperature range in which metal spraying takes place. It is completely impossible to escape due to temperature fluctuations that occur during the daily operation of reforming reactor systems, especially fluctuations during the processes of switching on and off the system, temperature fluctuations during cycling and temperature fluctuations that will occur when heating liquids in the reactor system.

Another approach to minimization of metal sputtering is to provide heating systems with --

Зз5 The use of superheated raw materials (such as, for example, hydrogen), thereby minimizing the need to heat hydrocarbons through the walls of the furnace.

Another approach to process modification consists in supplying the pre-existing reforming reactor system with pipes of a larger diameter and/or a higher flow rate of products in the pipes.

The use of pipes with a larger diameter and/or high speeds in the pipes will minimize the impact of hydrocarbons on heating the surface of the reactor system. As noted above, catalytic reforming is a well-known process in the oil industry and is used to process oil fractions to improve the octane number by production of aromatic compounds. The most important hydrocarbon reactions that take place in the reforming process include the dehydrogenation of cyclohexanes to aromatic compounds, the dehydroisomerization of alkylcyclopentanes to aromatic compounds, and the dehydrocyclization of acyclic hydrocarbons to aromatic compounds. In addition, a number of other reactions also take place, including dealkylation of alkylbenzenes, isomerization of paraffins, and hydrocracking reactions, resulting in the formation of light gaseous hydrocarbons, such as methane, ethane, propane, and butane; These hydrocracking reactions should be minimized during the reforming process, as they reduce the input of gasoline boiling products and hydrogen. Thus, the term "reforming" used here refers to the processing of hydrocarbon sulfur by using one or more reactions, in

He which aromatic compounds are produced in order to obtain a product enriched with aromatic compounds (that is, a product with a higher content of aromatic compounds than in sulfur).

Although the present invention is aimed primarily at catalytic reforming, it can be useful in general cases in the production of aromatic hydrocarbons from various hydrocarbon sulfur in conditions of low sulfur content. That is, although catalytic reforming typically relates to (F) crude oil conversion, it is equally possible to treat other crudes to produce an aromatics-enriched product. Thus, although crude oil conversion is the preferred embodiment, the present invention may be useful for conversion or aromatization of many types of sulfur, such as paraffinic hydrocarbons, olefinic hydrocarbons, acetylene hydrocarbons, cyclic paraffinic hydrocarbons, cyclic olefinic hydrocarbons, their mixtures, and especially saturated hydrocarbons.

Examples of paraffinic hydrocarbons are hydrocarbons having up to 10 carbon atoms, such as p-hexane, methylpentane, p-heptane, methylhexane, dimethylpentane and p-octane. Examples of acetylene 65 hydrocarbons are hydrocarbons with up to 10 carbon atoms, such as hexine, heptene, and octyne.

Examples of acyclic paraffinic hydrocarbons are hydrocarbons having from 6 to 10 carbon atoms, such as methylcyclopentane, cyclohexane, methylcyclohexane and dimethylcyclohexane. Typical examples of cyclic olefinic hydrocarbons are hydrocarbons containing up to 10 carbon atoms, such as methylcyclopentane, cyclohexene, methylcyclohexene, and dimethylcyclohexene.

The present invention will also be useful for reforming under low sulfur conditions using a variety of different reforming catalysts. Such catalysts include, but are not limited to, noble metals of the MIA group on refractory inorganic oxides, such as platinum on alumina and

RukKe on alumina; noble metal! MI groups on zeolites, such as Ri, RuizZp, and RukKe on zeolites, such as I-zeolites, 25M-5, silicalite, and beta; noble metal! MI groups on alkaline and 7/0 alkaline-earth exchange I -zeolites.

A preferred embodiment of the invention involves the use of a highly porous zeolite catalyst, including alkaline or alkaline-earth metals and charged with one or more metals of the MI group. The most preferred embodiment is the one in which such a catalyst is used for crude oil reforming.

The term "highly porous zeolite" refers loosely to zeolite having an effective pore diameter of 6 to 15 Angstroms. Preferably highly porous crystalline zeolites, which are useful in the present invention, include zeolite type I, zeolite X, zeolite M and foyasite. These zeolites have the right size! pores of the order of 7 to 9 angstroms. The most preferred zeolite is type Y zeolite.

The composition of type I zeolite, expressed in the molar ratio of oxides, can be presented in the form of the following formulas: (0.9 - 1.3) М»О : АийО»з (5.2 - 6.9) 5иО» : уУНЙО

In the above formula, M represents the cation, p represents the valency of M, and y can be any value from O to 9. Zeolite Y, its X-ray diffraction pattern, its properties, and its manufacturing method are described in detail, for example, in US patent No. 3,216,789 , on which m! here we meet.

The real formula can be changed without changing the crystal structure. For example, the molar ratio of silicon to aluminum (5I1/AI) can vary from 1.0 to 3.5.

The chemical formula of zeolite U, expressed in terms of molar ratios of oxides, can be written as: б зо (0.7 -1.1) Ма»О : АИ»2Оз : хВиО» : УНО

In the above formula, x is greater than 3, up to 6, and y can be up to 9. Zeolite M has a characteristic X-ray diffraction pattern on powder, which can be used together with the above formula for identification. Zeolite U is described in great detail in US Pat. No. 3,130,007, to which we refer here. --

Zeolite X is a synthetic crystalline zeolite molecular sieve, which can be represented by the formula: (0.7 - 1.) M»O : AlO»z : (2.0 - 3.0)510» : UNO

In the above formula, M represents a metal, in particular an alkaline or alkaline-earth metal, p is the valence of the metal, and can have any value up to 8, depending on the specific metal and the degree of hydration of the crystalline zeolite. Zeolite X, its X-ray diffraction pattern, its properties and its manufacturing method are described in detail! in US patent Mo 2,882,244, on which m! let's sit here. with In a highly porous zeolite, an alkali or alkaline-earth metal is preferably present. The alkaline earth metal can be barium, strontium or calcium, preferably barium.

Alkaline earth metal can be incorporated into zeolite during synthesis, by impregnation or by ion exchange. Barium is preferable to other alkaline earths, as it gives a somewhat lower catalyst acidity. Strong acidity is undesirable in the catalyst, as it promotes cracking, leading to lower selectivity. b In the second embodiment, at least part of the alkali metal can be exchanged for barium using the well-known method of ion exchange in zeolites. This method consists in contacting the zeolite with a solution containing an excess of Ba ions. The barium incorporated therein should preferably be from 0.195 to (Ce) 35965 of the weight of the zeolite.

Highly porous zeolite catalyst), used in the invention, is charged with one or more metals of the MI group, for example, nickel, ruthenium, rhodium, palladium, iridium or platinum. Preferred metals MI! groups include iridium and especially platinum. These metals are considered to be more selective in relation to dehydrocyclization, and they are also considered to be more stable under the conditions of iF) of the dehydrocyclization reaction than other metals! E! groups When using the preferred weight percentage of platinum in the catalyst lies between 0.195 and 595.

Metallic MI! groups! are introduced into highly porous zeolite! during synthesis, by impregnation or exchange in an aqueous solution of a suitable salt. If it is desirable to introduce two metals of the MI group into the zeolite, then these operations can be carried out either simultaneously or sequentially.

For a better understanding of the present invention, see below! the following are examples illustrating some aspects of the invention. It should be understood, however, that the invention is in no way limited to the individual details given below in these examples. 65 EXAMPLE 1

Tests were conducted to demonstrate the influence of sulfur and lead on carbonation in reforming reactors.

In those tests to study carburization and cracking of 347 stainless steel wire, copper pipes were used! eight inches long and 1/4 inch outside diameter. Three of those wires

0.035 inch diameter stainless steel blanks were inserted into the pipe, while a section of the pipe, four inches long, was held at a uniform temperature of 1250°C in the furnace. The pressure in the system was maintained at 50 bar. The reactor was charged with hexane at a rate of 25 microliters/min (1.5 ml/hour) and hydrogen at a rate of 25 cm3/min (the ratio of NO to hydrocarbons was 5 : 1). The methane content in the effluents was measured to determine the existence of isothermal methane reactions.

White filled control run using extra pure hexane containing less than 0.2 ppt of series. It was found that the pipe was completely filled with carbon only after three hours. That not only stopped the flow of hydrogen and hexane sulfur, the growth of carbon actually split the pipe and formed a spit! in the reactor. The content of methane in the flowing products was 60 - 80 wt.9o before plugging.

White completed a second run using essentially the same conditions except that 75 blobs were added with 10 ppt of sulfur. The run continued for 50 hours before it was stopped for wire research. No increase in methane content was observed during the run. It remained constant at the level of about 16 ves.96 o as a result of thermal cracking. No coke plugs were found, and no carbonization of steel wires was observed.

White is filled with another identical run, except that only 1 ppt of sulfur! was added (10 times less than in the previous run). This run showed little methane formation or plugging after 48 hours. Examination of steel wires showed a small amount of surface carbon and the absence of carbon bands.

Another run was completed with the difference that water in the amount of 1000 ppt (0.195) in the form of methanol was added to the hexane. Sulfur was not added. The run continued for 16 hours, however, no plugs were formed in the Ha reactor. However, after splitting the pipes! it was found that about 5095 pipes were filled with carbon. But the growth of carbon was not as sharp as during the control run. and)

EXAMPLE 2

The following father-in-law! conducted to determine suitable materials for use in low-sulfur reforming reactor systems; materials that should show better stability /-F

For carburizing, than mild steels, commonly used in the low-sulfur reforming technique.

In those tests, an apparatus was used, including a Lindbergh alumina furnace tube with a temperature controlled to within one degree using thermocouples installed on the outer surface of the tube in the heated zone. The furnace pipe had an inside diameter of 5/8 inch. Several runs were carried out at temperatures of 1200 "E using a thermocouple suspended inside a hot -

ZONY ("2 inch") pipes. The internal thermocouple constantly showed the temperature! by 0 - 10" There are smaller than the external thermocouple.

Samples of mild steels (C steel and 2 4/4 St) and samples of 300 series stainless steels were tested! at 1100"P, 11507 and 1200" for twenty-four hours and at 1100" for ninety hours, in conditions that simulate the retention of materials in low-sulfur reforming conditions. Samples of various materials were placed in open quartz boats inside the heated zone The boats were one inch long and 1/2 inch wide and fit well inside the two-inch hot zone of the pipe. The boats were attached to silica glass rods for insertion and removal. Internal thermocouples were not used when the boats got stuck inside the pipes!

Before starting the test, the white pipe was flushed with a stream of nitrogen for several minutes. Carburizing gas in the form of a commercially prepared mixture of 7956 propane in hydrogen was passed through a liter flask of 1 toluene at room temperature in order to introduce about 195 toluene into the feed gas mixture. Atmospheric pressure and gas flow were maintained in the apparatus in the range from 25 to ZOsmU/min. The samples were brought to working temperatures! with a speed of 144"R/min. (22) After holding the materials in the carbonizing gas for the desired period at the desired temperature of 50, the apparatus was cooled by a flow of air directed to the outer surface of the pipes! When the apparatus was sufficiently cold, the hydrocarbon gas was removed with the help of nitrogen , and the boat took care of

Me, trumpet! for research and analysis.

Before the beginning, the tested material! were cut to the size and shape suitable for immediate visual identification. After any preliminary treatment, such as cleaning or roasting, the samples were weighed. Most samples weighed less than 300 tenge. Typically, each run was conducted with three to five samples in a boat. A sample of 347 stainless steel was present in each run as an internal standard. име) After completing each run, the conditions in which the boat and each material were located were carefully recorded. The boat was casually photographed. Each material was then weighed to determine the changes, taking care to preserve any coke deposits on the corresponding substrate materials. Exemplary! then they were filled in epoxy resin, primed and polished in order to prepare them for petrographic analysis and analysis on an electron scanning microscope to determine coking, metal spraying and carburization of each material.

Necessarily, the holding time in the carbonizing gas used in these tests would be much longer than in typical commercial operations. Thus, it was believed that experimental conditions can be more severe than commercial conditions. Some of the materials

which did not suffer from those tested, may well beat commercial prospects. Nevertheless, the test provides a reliable indicator of the relative resistance of materials to coking, carbonization and metal spalling.

The result! haunted ghost! in the following table 1. 7 Veezhpryaryuuts| 0000 Sprayed Composition, war 00000010 to bel11111100860000000000000000000000000000000000000000

Open 0000 iv vyaau 01110080 Raiu 000000 jan nin ne With port 00000 2 S vetel/o 0 TracesTraces of logging

MES NI PO NN me nin ns oz pievochayu 00001 sch 2" in 000000050000000000 already o et 81000000reyuv vm 8 o vmy11Ch4e (22) x 1596 C7Na w 5095 SzNv w No (by weight) o

Of course, the above is the result! are recognized as qualitative and depend on the morphology of the surface, i.e. the microscopic roughness of the metals. The increase in carbon weight is an indicator of surface coking, which is autocatalytic. "--

EXAMPLE C

Similar to the one used above, the method was again used to test a wide range of materials at a temperature of 1200°C for 16 hours. The results are presented below. Each group represents a comparison of different materials placed in one boat under identical conditions. Write with cotton wool 00000021 Temperance 7 words" 0 - 80000008 Myatov, oBotom

Ф in the following that here 11 s excludes 00000001 Moderates

Alonized CJSC 000000000003000 Led in the trace here 11 o yuyu. thin oxide crust

EXAMPLE 4 65 White research and additional material! again using the methods described in example 2 (if not noted! other methods).

Specimens of 446 stainless steel and 347 stainless steel were placed in a sample boat and tested simultaneously in a carburizing apparatus at 110°E for two weeks. 446 stainless steel had a thin coke coating, but no other changes were noted. On the other hand,

CJSC Stainless Steel had a massive localization of coke deposition and pitting, more than 4 miles deep (mil - 1 thousandth of an inch), from which coke and metal dust erupted.

White samples of carbon steel, protected by electrodeposition with tin, silver, copper and chromium were also tested. The samples had a coating with a thickness of approximately 0.Bmil. After a 16-hour carbonization test at 1200 E, coke was not formed on the protective film of deposited 7/0 tin and deposited chromium. Coke was formed on the protective film of deposited silver and deposited copper, but only in those places where the coating had peeled off. Failure to cover the samples ! carbon steel was tested simultaneously with protection samples, demonstrating sharp carburization with coke and sputtering of the metal.

White samples of protected 304 stainless steel were also tested; one of the tin, silver, copper, and chromium coatings was applied to each sample /5 using the spectrogalvanic method. Sample! had a coating with a thickness of approximately 0.5 mil. After a 16-hour experimental carburizing test at 1200°C, no coke was formed on any of the coated deposits, with the exception of local deposits on the protective coating of deposited copper in places where the coating had swelling and peeling. A thin coating of coke was observed on unprotected samples of 304 stainless steel, which were tested simultaneously with deposited protective coatings.

White samples of the protective coating of 304 stainless steel; one of the tin and chromium coatings was applied to each sample using the electrogalvanic method. Ask for samples! were tested simultaneously with a sample of 446 stainless steel in a carburizing test at 1100 "P. The samples were kept in the apparatus for five weeks. Every week, the samples were cooled to room temperature for observation and photographic documentation. Then they were reheated to 1100 "P.

The protective coating of deposited tin was white, free from coke, the protective coating of deposited chromium i) was also white, free of coke, except for local places where the chrome coating was peeling off. A piece of white 446 stainless steel is uniformly coated with coke.

Samples of uncoated MInconel 600 (7595 Mi) and tin-coated (by electrogalvanic method) Mnconel 600 (75950 Mi) were tested at 1200"E for 16 hours. The tin-coated sample coked and spalled, but not to the same extent as the uncoated sample o

EXAMPLE 5 "o

The following experiments were performed! to study the isothermal reaction of methanation, which takes place during the processes of formation and burning of coke balls during reforming in the conditions of low - z5 sulfur content. In addition, tin was studied as an additive that reduces the formation of methane. yu

Coke deposits containing molten iron particles were found in the low-sulfur reforming reactor system. Such a formation of molten iron during the reforming process at temperatures between 900 and 1200" is considered to be caused by highly x-isothermal reactions taking place during the reforming process. High temperatures are particularly surprising, since reforming, generally speaking, is endothermic in nature and really tends to cool the reactor system. High temperatures can ;" generated inside well-insulated coke balls by diffusion of hydrogen into the places of catalytic spraying of iron, where it catalyzes the formation of methane from coke and hydrogen.

Whites were used in this experiment! steel hairs for studying the formation of methane in a small pilot plant. 0.14 gram of steel hair was packed into a 1/4-inch stainless steel tube and placed in a furnace at 1175". were kept in b hydrogen for twenty hours before the introduction of hexane. Then hexane was introduced into the reactor at a rate of 29 microliters/min at a hydrogen velocity of about 2 Bcm/min. At first, methane formation was low with a tendency to increase with continued distillation, (Che) was finally reached 4.596. Then 0.1 cm of tetrabutyltin dissolved in 2 cm of hexane was introduced into the sulfur purge stream ahead of the iron. Methane production decreased to about one percent and continued at 195 for the next three hours. The data are summarized in the table

With, given below. о ю за оо 05 03 в во b5 23.0|11.16| 3.96 424 85.9

From the above results, it can be seen that the addition of tin to steel fibers stops the acceleration of methane formation and lowers its content in the product to acceptable levels.

EXAMPLE 6

Have fun! additional experiments with the use of steel hairs previously /0./ coated with tin tetrabutyl. In particular, as in Example 5, three injections of a solution of 0.1 cm of tetrabutyltin in 2 cm? of hexane into a 1/4-inch steel tube containing 0.15 grams of steel hair.

The solution was passed through steel hairs in a stream of hydrogen at 900"P.

Then, hydrocarbon sulfur was introduced at 1175 °C with a hydrocarbon rate of 25 microliters/min and a hydrogen velocity of about 25 cm3/min. The exit gas was analyzed for methane content, which remained below 195 for 24 hours. Then the reactor was stopped, the reactor tube was opened and investigated.Very slight carburization took place on the steel hairs.

On the contrary, a control experiment was conducted without preliminary treatment with tin tetrabutyl. It was held over the course of one day under conditions similar to those described above. After 24 hours at the exit of the pipes! neither hydrogen nor hydrocarbon sulfur can be registered white. The inlet pressure increased to 300 |B85 from the initial 50 Ir5. When the reactor tube was opened and examined, it was found that the coke had completely blocked the tube.

Thus, it can be seen that tin-organic compounds can prevent carbonization of steel hairs under reforming conditions.

EXAMPLE 7 p

Another experiment of the control experiment of Example 1 was conducted to investigate the effect of carbonizing conditions on stainless steel wires coated with tin from the vapor phase, placed in a reactor tube protected by gold electrodeposition. The experiment differed from the control one only in that a higher rate of hydrogen pumping, about 100 ml/min, was used.

The run continued for eight hours without clogging or the formation of excess methane. When F) the white tube was opened and analyzed, neither clogging nor streaks of carbon were observed. Only one black vein of carbon appeared on the wire. Probably, it is due to insufficient quality - coverage. Gee)

This experiment shows that tin can protect stainless steel from carburizing like sulfur. However, unlike series, ego does not need to be continuously injected into series. Sulfur must be - Continuously introduced into the sulfur to maintain the partial pressure of hydrogen sulfide in the system at a sufficient level to maintain the sulfide surface on the steel. Any removal of sulfur from the sulfur will lead to the beginning of carbonization after the reactor system is depleted of sulfur. This usually happens within 10 hours after removing sulfur.

While the invention has been described above in terms of a preferred embodiment, it should be understood that various changes and modifications may be used, as it may be appreciated by ordinary people. For example, part of the steel in the reactor system can be covered with niobium, zirconium, silica ceramics, tungsten or chromium (chromization), although this is possible! they could be too "" complicated for execution or use or too expensive. If the use of heat exchangers for heating hydrocarbons to the reaction temperature could be minimized. The heat could be provided by superheated hydrogen. If the exposure time of heated surfaces in hydrocarbons can be reduced by using pipes of a larger diameter and higher speed of movement in the pipes. It is important because there are many changes and modifications of the above preferred embodiments of the invention, which will be readily apparent to ordinary people and which are discussed within the framework of the invention, as defined by the following claims. at 50

Claims (1)

Formula of the invention (Che) 1. The method of catalytic reforming of a hydrocarbon, including the stage of interaction in a sulfur-sensitive zeolite reforming catalyst with a hydrocarbon, under conditions of low content, less than about 100 pp of sulfur in a reactor system equipped with a set of furnace tubes, distinguished by F) that it is part of reactor systems! has resistance to carburization and metal oxidation at least not lower than stainless steel, under reforming conditions with a low sulfur content. 2. The method according to claim 1, characterized by the fact that a zeolite catalyst is used as a sulfur-sensitive zeolite catalyst for reforming. C. The method according to claim 1 or 2, which is distinguished by the fact that resistance to carburization and precipitation of metal in the conditions of reforming with a low sulfur content! at least not lower than that of stainless steel brand 300. 4. The method according to claims 1-3, characterized by the fact that the resistance to carburization and oxidation of the metal in 65 conditions of reforming with a low content of the series is at least not lower than that of stainless steel of the brand 347. 5. The method according to claims 1-4, characterized by the fact that the reactor system includes a refractory furnace. 6. The method according to claim 5, characterized by the fact that many furnace pipes are located in one furnace. 7. The method according to claims 1-6, characterized by the fact that it is part of a reactor system! has at least one of the plurality of furnace tubes. 8. The method according to claims 1-7, distinguished by the fact that it is part of the reactor system! is part of the wall of the reactor system. 9. The method according to claims 1-8, characterized by the fact that the conditions of low content of the series include at least a content of the series less than, approximately, 50 rrb (number of parts per billion). 70 10. The method according to claims 1-9, characterized by the fact that the reaction stage is carried out in conditions of low water content. 11. The method according to claims 1-10, characterized by the fact that the interaction stage is carried out under the condition that the water content is 1000 rrb (number of parts per million) or less. 12. The method according to claim 1 or 3-11, characterized by the fact that coarse-grained zeolite is used as a sulfur-sensitive catalyst of 7/5 Vyforming, which includes an alkaline or alkaline-earth metal and at least one metal from MI! groups 13. The method according to claim 12, characterized by the fact that as a metal MI! groups use platinum. 14. The method according to claims 1-13, characterized by the fact that resistance to carburization and corrosion of the metal is provided by means of plating, coating or paint on part of the reactor system. 15. The method according to claim 14, characterized by the fact that as a paint, a paint capable of recovery is used, which is further subjected to a heating stage under appropriate conditions of recovery. 16. The method according to claim 15, characterized by the fact that the heating stage is carried out in the presence of hydrogen. 17. The method according to claim 14 or 15, characterized by the fact that tin-containing paint is used as a paint. 18. The method according to claim 17, characterized in that the tin-containing paint additionally includes a hydrogen-decomposable tin compound, a solvent system, finely divided metallic tin and tin oxide. 19. The method according to claim 17 or 18, characterized in that the tin-containing paint additionally includes a tin-containing compound and an iron compound, while the iron-tin ratio is less than approximately 1:3 by weight. Gee! 20. The method according to claim 14 or 15, characterized in that the paint includes metal oxide. 21. The method according to claim 14 or 15, characterized by the fact that the paint includes a compound capable of being decomposed by hydrogen. "at 22. The method according to claim 14, characterized by the fact that the coating material is selected from the group consisting of copper, tin, intermetallic compounds of tin, alloys of tin, arsenic, antimony, brass, lead, bismuth, -- with 5 Chromium, intermetallic compounds based on them , alloys based on them, copper-tin alloys, alloys (in copper-antimony), and mixtures based on them. 23. The method according to claim 22, characterized by the fact that the applied coating retains resistance to carburization and metal spalling after oxidation. 24. The method according to claim 14, characterized by the fact that the coating material is selected from the group consisting of "70 aluminum, aluminum oxide, chromium, chromium oxide, alithiated material, chromed materials of mixtures based on /-7-Z". 25. The method according to claim 14, characterized by the fact that ceramic is used as an applied coating; cover 26. The method according to claim 14, characterized by the fact that silicon PPOC coating is used as an applied coating. c 27. The method according to claims 1-13, characterized by the fact that resistance to carburization and corrosion of the metal is provided by applying a layer of metallic stannite on part of the reactor system. - 28. The method according to claims 1-13, characterized by the fact that it is part of a reactor system! they are filled with material that provides resistance to carburization and corrosion of the metal. 29. The method according to claim 28, characterized by the fact that it is part of a reactor system! They are made of stainless steel grade 347 or its resistance to carburization and metal spalling is at least not less than that of stainless steel grade 347. 30. The method according to claims 1-13, characterized by the fact that the resistance to carburization and metal corrosion is provided by the modification of the process stage, which is selected from the group that includes the operation of the reactor in the system! at a lower reforming temperature, superheated flow with low sulfur content, operation of reactor systems! with two temperature zones, the operation of a reactor system with staged (F, heaters or furnace tubes, the operation of a reactor system with staged heaters and staged furnace tubes, the operation of a reactor system in which the surfaces of the reactor systems are subjected to minimal heating by hydrocarbons, and combinations of them, using which provides increased resistance of part of reactor systems to carburization and metal precipitation. 31. The method according to claims 1-13, characterized by the fact that the resistance to carburization and corrosion of the metal is provided by adding a non-sulfur, anticarburizing, anticoking substance to the reactor system. 32. The method according to claim 31, characterized by the fact that the non-sulfur, anti-carburization substance is selected from 65 groups, including organometallic compounds, organotin compounds, organoantimony compounds, organobismuth compounds, organoarsenic compounds, organolead compounds, tetraethyl and tetramethyl lead, tetrabutyltin, trimethyltin hydride , bismuth neodecanoate, chromium octoate, copper naphthenate, manganese carboxylate, palladium neodecanoate, silver neodecanoate, tetrabutyl germanium, tributyl antimony, triphenyl antimony, triphenyl arsenic, zirconium octoate and compounds based on them. 33. The method according to claim 1-32, characterized by the fact that it is a reactor system! use a known reactor system. 34. The method according to claim 1-32, characterized by the fact that a new reactor system is used as a reactor system. 35. The method according to claim 1-34, characterized by the fact that part of the reactor system), the preceding part of the reactor system, which has the specified resistance to carburization and metal deposition, is made of oxidized steel. 36. The reactor system for catalytic reforming under conditions of low sulfur content includes: a furnace containing a set of furnace tubes, a reforming reactor, including a substrate for a sulfur-sensitive catalyst, distinguished by the fact that it is part of a reactor system! for catalytic reforming, which is in contact with a hydrocarbon stream with a low content of series, and has increased resistance to carbonization. 37. The reactor system according to item 3b, characterized by the fact that the I-zeolite catalyst is used as a sulfur-sensitive zeolite reforming catalyst. 38. A reactor system according to claim 36 or 37, characterized by the fact that it is part of a reactor system! of catalytic reforming is at least one of many furnace tubes. 39. A reactor system according to claim 36 or 37, characterized by the fact that it is part of a reactor system! of catalytic reforming is part of the wall of reactor systems! 40. The reactor system according to claim 36-39, characterized by the fact that the stream with a low content of serium contains less than approximately 100 ppm (number of parts per billion) of arsenic. 41. The reactor system according to claim 36-40, characterized by the fact that the stream with a low content of series contains less than approximately 50 rrb (number of parts per billion) of series. and) 42. The reactor system according to claim 36-41, characterized by the fact that the sulfur-sensitive catalyst is a coarse-grained zeolite containing an alkaline or alkaline-earth metal and at least one MI metal! group! Gee! z 43. The reactor system according to claim 42, characterized by the fact that platinum is used as the metal of the MIII group. at 44. Reactor system according to claim 36-43, characterized by the fact that increased resistance to carbonization of Ge is provided by cladding, coating or paint on part of the reforming reactor. 45. The reactor system according to claim 44, characterized by the fact that as a paint, a paint capable of 00/87 z5 regeneration is used, which is heated in the conditions of restoration. yu 46. Reactor system according to claim 44 or 45, characterized by the fact that tin-containing paint is used as paint. 47. The reactor system according to claim 46, characterized by the fact that the tin-containing paint additionally contains a hydrogen-decomposable tin compound, a solvent system, finely divided metallic tin "Pin oxide". шщ с 48. Reactor system according to claim 44, characterized by the fact that the coating material is selected from groups including copper, tin, intermetallic compounds of tin, alloy! tin, arsenic, antimony, brass, lead, bismuth, chromium, intermetallic compounds based on them, alloy! based on them, a copper-tin alloy, a copper-antimony alloy, and mixtures based on them. 49. The reactor system according to claim 44, characterized by the fact that the coating material is selected from the group consisting of aluminum, aluminum oxide, chromium, chromium oxide, alithiated material, chromed material and mixtures based on them. - 50. The reactor system according to claim 44, characterized by the fact that a ceramic coating would be used as an applied coating. 51. Reactor system according to claim 44, characterized by the fact that a silicon coating is used as an applied coating. Ge) 52. Reactor system according to claims 36-43, distinguished by the fact that it is part of a reactor system! catalytic reforming includes a protective layer containing metallic stannite, which provides increased resistance to carburization. 53. The reactor system according to claims 36-43, characterized by the fact that it is part of a reactor system! they are made of a material that provides resistance to carburization and corrosion of the metal. (Ф, 54. Reactor system according to claim 53, characterized by the fact that stainless steel grade 347 is used as a material or a material whose resistance to carburization and metal corrosion is not lower than that of stainless steel grade 347 when reforming in conditions with low content sulfur!. in 55. The reactor system according to claims 36-54, characterized by the fact that the part of the reactor system, which precedes the part of the reactor system with increased resistance to carburization and metal deposition, is filled with oxidized steel. Official Bulletin "Industrial Property". Book 1 "Inventions, useful models, topographies of integrated 65 microcircuits", 2002, M 12, 15.12.2002. State Department of Intellectual Property of the Ministry of Education and Science of Ukraine.