CN1039720C - Low-sulfur reforming processes - Google Patents

Abstract

The present invention discloses a method for reforming hydrocarbons comprising contacting the hydrocarbons with a catalyst in a reactor system of improved resistance to carburization and metal dusting under conditions of low sulfur.

Description

Low-sulfur reforming processes

The application is that application number is 07/666696, the applying date be on March 8th, 1991 U. S. application (thereby, its content is cited as a reference) the subsequent application of part, it and U.S. Patent application 802,821 (proxy's registration number is 005950-316) and U.S. Patent applications 803,215 (proxy's registration number is 005950-333) are relevant, and these two parts applications are filed an application simultaneously together, and here all are cited as a reference.

The present invention relates to some and be used for catalytic reforming, is exactly doctor negative specifically, and the improvement technology of the catalytic reforming under low-sulfur and low water condition.More specifically say, the present invention relates to find and control those and doctor negative, and the closely-related especially problem of the reforming process of low-sulfur and low water.

Catalytic reforming is that the people is known in petroleum industry, and it relates to the processing naphtha fraction, so that come boosting of octane rating by forming aromatic hydrocarbons.The important hydrocarbon reaction that occurs in the reformation operational process comprises that cyclohexane dehydrogenation becomes aromatic hydrocarbons, the alkyl cyclopentane dehydrogenation-isomerization becomes aromatic hydrocarbons and acyclic hydro carbons dehydrocyclization becomes aromatic hydrocarbons.Various other reactions also can take place, comprise alkylbenzene dealkylation, paraffin wax isomerization reaction and some hydrocarbon hydrocracking reactions, these hydrocarbon hydrocracking reactions produce light gaseous hydrocarbons, for example methane, ethane, propane and butane.Importantly some hydrocarbon hydrocracking reactions in the reforming process are minimized, because these reactions have reduced the yield of gasoline boiling product and hydrogen.

Owing to need high-octane gasoline, now carried out extensive studies for improving the reforming catalyst and the catalytic reforming process that have improved.The catalyzer that is used for good reforming process must possess good selectivity.In other words, they tackle in the liquid product of producing high yield should be highly effective, and described liquid product contains the enriched material of a large amount of high-octane aromatic hydrocarbons in the gasoline boiling spread.Equally, the yield of gaseous light hydro carbons should be lower.These catalyzer should have good activity, so that make too high temperature be reduced to bottom line, so just can produce the product of certain grade.This catalyzer also must or have satisfactory stability, so that can keep it active and characteristic such as select to give birth in the long operational process that continues, or can regenerate fully, so that can repeated regeneration and do not lose its performance.

Catalytic reforming also is a kind of important technology of chemical industry.Now growing to the demand of aromatic hydrocarbon, these aromatic hydrocarbon are used for making various chemical productss, for example synthon, sterilant, tackiness agent, washing composition, plastics, synthetic rubber, medicament production, stop bracket gasoline, perfume, siccative oil, ion exchange resin and are well-known various other products to this professional domain those skilled in the art.

Occurred a kind of important techniques progress aspect catalytic reforming recently, this relates to and uses some macrovoid zeolite catalysts.The feature of these catalyzer also is to contain basic metal or alkaline-earth metal, and they are filled with one or more the 8th family metals.Have found that such catalyzer helps to provide more in the past than higher selectivity of the catalyzer that used and longer catalytic life.

In case after having found to have the catalysts selective in gratifying cyclical operation life-span, successful commercialization is seemingly inevitable.Subsequent regrettably discovery again contains a kind of highly selective of metal of the 8th family, macroporous catalyzer is very easy to take place sulfur poisoning.See United States Patent (USP) 4456527.To find at last, in order addressing this problem effectively, the sulphur content of the hydro carbons that injected should to be reduced to extremely low level, better is less than 100ppb, is more preferably less than 50ppb, so that make catalyzer reach gratifying stability and activity level.

Be familiar with relevant with these new catalysts to sulphur susceptibility and determined sulphur in the technological process necessity with acceptable content after, good prospect appears in successful commercialization once more; Just will avoid another relevant problem occurring, it is found that, under typical reaction conditions, the existence of water has adverse influence to some macrovoid zeolite catalyst.Particularly, it is found that water has quickened the speed of catalyst deactivation widely.

It is found that, be a kind of major defect that is difficult to effectively solve to the susceptibility of water.At catalyzer during, all produce water in the beginning of each technological cycle by hydrogen reduction.When seepage is in the reformer material, or material also can produce water when being polluted by oxygenatedchemicals in the not normal process of these technologies.At last, also work out some technology and be not subjected to the harm of water in order to protect these catalyzer.

Along with the development of the various low-sulfurs that are used for catalytic reforming (these catalytic reforming process have adopted the highly selective macrovoid zeolite catalyst with long catalytic life), low water system, commercialization is exactly practicable once more.Low-sulfur/low water system is effectively at first, yet it is found that, this reactor assembly is possible after about several week only must stop.The reactor assembly of a pilot plant is only just having blocked regularly phenomenon through such short-time duty week after date.It is found that tamper is the thing of those cokings and so on.Yet although be a kind of common problem in the hydrocarbon production process at the coking phenomenon among the granules of catalyst, forming degree and the speed that coke stops up outside the granules of catalyst relevant with this special system is people's expectation head and shoulders above.

Therefore, an object of the present invention is to provide a kind of method of under the low-sulfur condition hydro carbons being reformed, this method has been avoided foregoing those problems, it is found that these problems and low-sulfur technology (for example short the cycle of operation) is related.

Another object of the present invention just provides a kind of reactor assembly that hydro carbons is reformed of being used under the low-sulfur condition, this system makes us can obtain the long cycle of operation.

After the coke tamper to the low-sulfur reactor assembly had carried out detail analysis and research, they contained metallic particle and molten drop (droplets) beat all discovery; The distribution of sizes of these molten drops gets and maximumly reaches several microns.This observed result makes the people recognize to exist some new extremely serious problems surprisingly, and these problems and traditional reformation technology are irrelevant, and in traditional reformation technology, the content of sulphur and water is obviously much higher in the technical process.More particularly, it is found that there are some problems that these problems are endangering the effective and economic processing property of this system, and the mechanical integrity of this equipment.People find that also the appearance of these problems is owing to the low-sulfur condition, and to a certain extent also because low water condition.

In the past four during the decade, the catalytic reforming reactor system makes with common low charcoal steel (for example 2 1/4Cr1Mo).During this period of time whole, experience had shown about 20 years of the operation that these systems can be successful already and physical strength can significantly not reduce.Yet, in the coke obturator, find the metallic particles and the powder that comes off, finally caused the research of people to this reactor assembly mechanical characteristics.Quite it is shocking and found such certain situation, these situations show that whole reactor assembly exists the CR Critical mechanical aging of potential, this system comprise boiler tube, pipeline, wall of reactor and some other around medium, for example contain the catalyzer of iron and the metallic screen in the reactor.Finally, it is found that this problem is relevant with the serious carburizing of steel, this carburetion is owing to the carbon in the technological process is injected the embrittlement that metal causes steel.It is contemplated that therefore catastrophic mechanical accident can take place this reactor assembly.

According to traditional reformation technology, the carburetion problem that is nothing does not simply include significant problem in other words; Do not reckon with that it can appear in present low-sulfur/low water system.And, it is believed that traditional processing unit can also use.Yet obviously the existence of sulphur has suppressed carburetion effectively in traditional system.Do not know why, in traditional technology, the sulphur in the technological process has interference to carburization reaction.But for the extremely low low-sulfur system of sulphur content, this inherent provide protection has just no longer existed.

Figure 1A is the partial Photomicrograph in inboard (technical process side) of a soft steel boiler tube of Zhang Gong industry reformer apparatus.This boiler tube has exposed about 19 years under traditional the condition of reorganization.This photo shows that the surface of this pipe remains unchanged basically, and the texture of pipe at high temperature still keeps normal (part that photo is black is a background) through long-term exposure after hydro carbons.

Figure 1B is a partial Photomicrograph of soft steel coupon sample, and this sample was only placed 3 time-of-weeks at the inside reactor of a low-sulfur/low water demo plant.This photo shows the surface (comparing with black background) that this sample has been corroded, and occurs the metal-powder obscission on this surface.The Dark grey texture shows the carburizing phenomenon on every side of steel, and it is dark that the carburizing of steel and cracking surpass 1mm.

Certainly, those relevant with carburetion problems are because the carburetion of this mechanical system causes.The carburizing of steel wall has caused " metal-powder comes off " (metal dusting), has the particle of catalytic activity and the appearance of metal drop and is caused by corrosion of metal.

These reactive metal particulates provide extra place for form coking in system.When the catalyst deactivation that causes owing to coking became the problem that must solve at large in reforming process, a new problem that coke stops up had been brought in the source of the important formation coking that this is new, and this just makes original problem even more serious.In fact, it is found that in general mobile active metal particles and coke grain make coking shift along system.These active metal particles be actually on they self or in system the place of any particle aggregation bring out coking, cause the coke that heat release demethanizing reaction occurred to stop up and the hot-zone.As a result, reactive system tractable, not too early coke occurred and has stopped up, and this may cause stopping production in several weeks after driving.Yet, use technology of the present invention and reactor assembly can overcome these problems.

Therefore, first aspect of the present invention relates to a kind of method that hydro carbons is reformed, this method comprise make hydro carbons in the reactor assembly an of the following stated, low-sulfur and normally under the condition of low-sulfur and low water the catalyzer with the following stated contact; Described reactor assembly has the performance that impervious carbon and anti-metal-powder come off, and is the improvement to traditional soft steel reactor assembly; Described catalyzer preferably contains basic metal or alkaline-earth metal and is filled with the macroporous zeolite catalyst of one or more the 8th family metals; In reforming process, described anti-carburizing can be such, makes the cracking that causes owing to carburetion will be less than 2.5mm/, is preferably to be less than 1.5mm/, more preferably is less than 1mm/, is preferably to be less than 0.1mm/.Prevent that embrittlement from reaching the metal-powder that a kind of like this degree will reduce significantly in reactor assembly and coming off and coking, and make system can move the longer time.

Another aspect of the present invention relates to a kind of reactor assembly, and this system comprises having the device that impervious carbon effect and anti-metal-powder come off.This system is a kind of improvement that traditional soft steel system is undertaken by following a kind of hydrocarbon reformation method, described method has been utilized a kind of reforming catalyst under the low-sulfur condition, for example include alkaline-earth metal and be filled with the macrovoid zeolite catalyst of one or more the 8th family metals, the performance that described impervious carbon effect and anti-metal-powder come off reaches such level, feasible cracking will be less than 2.5mm/, be preferably less than 1.5mm/,, be preferably less than 0.1mm/ more preferably less than 1mm/.

Therefore, among other factor, the present invention is based on a kind of like this discovery, promptly at low-sulfur, and exist significant carburetion, metal-powder to come off in the reforming process of low-sulfur and low water and problem such as coking, and these problems do not reach tangible degree in traditional reforming process, because in traditional technology, the content of sulphur is than higher.The way that this discovery has impelled people to go to carry out nervous work and research and solve these problems, these terms of settlement are novel to low-sulfur reforming, and relate to the material that is used for the low-sulfur reforming system with performances such as impervious carbon discriminating and selection, effectively utilize and use this method with material of performances such as impervious carbon, be used to reduce carburetion and metal-powder comes off and the additive of coking (non-sulphur), various process modification and structure and their combination, these factors have solved described those problems effectively.

More particularly, this discovery has caused exploration, discriminating and the selection of people to the material with impervious carbon species performance that is used for low-sulfur reforming system (particularly wall of reactor, boiler tube and sieve wherein), these are operated in traditional reforming system, for example some steel alloy and stainless steel, aluminize and the system Central Plains of chrome-plated material and some stupalith is unnecessary.In addition, people also find, some other special material, for example be used for galvanized, metalclad, coating or the like, also may have performances such as effective impervious carbon.These materials comprise copper, tin, arsenic, antimony, brass, lead, bismuth, chromium, their intermetallic compound, and their alloy, also comprise silica and silica-based coating.In a kind of preferred embodiment of the present invention, provide a kind of novelty and stanniferous coating that have resistance.

In addition, this discovery has caused some additive of development, is referred to as anti-carburizing agent and anti-coking agent following.For necessity, these additives are substantially free of sulphur, sulfur-bearing not fully preferably, and these additives are novel for the reformation technology.Some additives comprise organo-tin compound, organo-antimony compound, bismuth organic compound, organoarsenium compound and organo-lead compound like this.

And it is unnecessary some process modification and process structure that some problems relevant with low-sulfur reforming also impel people to go to study in traditional reforming process Central Plains.These problems comprise the utilization of the utilization of utilization, ultrahigh-temperature raw material of utilization, the fractionated humidity province of the utilization of the ultrahigh-temperature hydrogen between some temperature control technology, the reactor, more frequent catalyst regeneration, fractionated well heater and boiler tube and bigger caliber and/or higher velocity in pipes.

Such as the above mentioned, Figure 1A is a Photomicrograph of taking from inboard (technical process side) part of a kind of soft steel boiler tube of an industrial reformer.This device used 19 years, and this is also such as the above mentioned.

Figure 1B is a partial Photomicrograph of a kind of soft steel coupon sample, and this sample only placed for 13 weeks in the inside of a reactor of a low-sulfur/low water demo plant.

Fig. 2 is to being used for the synoptic diagram of a kind of suitable reforming reactor system of the present invention.

Here employed metallurgy noun is got justice in the contained popular metallurgy implication of metals handbook (THE METAL HANDBOOK of the American Society of Metals) of American Society of Metals (ASM).For example, " carbon steel " is meant that those do not specify steel minimum quantity manganese, silicon and the copper of quantity (rather than refer to usually to generally acknowledge) and arbitrary element (except carbon, silicon, manganese, copper, sulphur and the phosphorus) that only contain minute quantity to the element of forming content arbitrarily." soft steel " is meant that those carbon contents are 0.25% carbon steel to the maximum.Steel alloy is meant that those contain the steel of the alloying element of the specified quantity that adds for the variation that influences character machinery or physics (manganese, copper, silicon, sulphur and the phosphorus that are not meant carbon and generally acknowledge quantity usually).The contained chromium of steel alloy will be less than 10%.Stainless steel is severally to contain 10% at least, and preferably 12% to 30% chromium is as in the steel of main alloy element any one.

Therefore, in general, a focus of the present invention just provides a kind of improved method that is used for hydrocarbon reformation, this method is utilized a kind of reforming catalyst under the low-sulfur condition, especially contain basic metal or alkaline-earth metal and be filled with the macrovoid zeolite catalyst to sulfur sensitive of one or more the 8th family metals.Certainly, a kind of like this technology must show that its anti-carburizing can be better than traditional low-sulfur reforming technology.

A way utilizing the present invention to address this problem just provides a kind of reactor assembly of novelty, this system can include one or more various devices, be used in reforming process improving impervious carbon and the anti-metal-powder performance that comes off, this reforming process has been utilized a kind of reforming catalyst under the low-sulfur condition, for example foregoing macrovoid zeolite catalyst to sulfur sensitive.

Here used " reactor assembly " is meant at least one reforming reactor and furnace apparatus correspondingly and pipeline.Fig. 2 shows one and is suitable for implementing typical reforming reactor of the present invention system.It can comprise a plurality of reforming reactor (10), (20) and (30).Each reactor comprises a catalytic bed.This system also comprises a series of stoves (11), (21) and (31); Heat exchanger (12); And separator (13).

Research by relevant with the present invention it is found that, those problems relevant with low-sulfur reforming noted earlier can be solved effectively by select a kind of suitable reactor assembly material that contacts with hydro carbons in technological process.Usually, the reforming reactor system makes with soft steel or steel alloy (for example typical chromium steel), and it is inappreciable that carburetion and powder come off.For example, the 21/4Cr boiler tube can continue to use 20 years under the standard the condition of reorganization.Yet, it is found that the steel of these kinds is inapplicable under the low-sulfur reforming condition.Because carburetion, embrittlement just promptly took place in them in about 1 year.For example, it is found that the carburizing of 21/2Cr1Mo steel and embrittlement are greater than 1mm/.

It is found that in addition, according to the metallurgy convention of standard be considered to can anti-coking and those materials of carburizing be not anti-coking and the carburizing performance that necessarily has in the low-sulfur reforming condition.For example rich nickelalloy (as Incoloy 800 and 825, Inconel6600, Marcel and Haynes230) can not adopt, because they the intensive coking can occur and metal-powder comes off.

Yet, 300 series stainless steels, preferably 304,316,321 and 347 is the materials that can adopt at least as the several portions that contacts with hydro carbons of reactor assembly of the present invention.The ability that it has been found that their impervious carbon is higher than soft steel and rich nickelalloy.

Originally, it is believed that the material of aluminizing, for example those (" AlonizedSteels ") materials of Alon company sale can not provide sufficient impervious carbon protection in reforming reactor system of the present invention and technology.Yet it is found that afterwards, thin film aluminium or aluminum oxide is added on the metallic surface of reforming reactor system, perhaps use the Alon steel during fabrication fully, just can be provided at and have the enough impervious carbon and the surface of metal-powder exfoliation ability under the low-sulfur reforming condition.Yet such material is quite expensive, and when they have impervious carbon and anti-metal-powder when coming off performance, just tends to explosion, and the significantly reduction of its tensile strength.The underlying metal that cracking will be layered on the bottom comes out, and it is become under the low-sulfur reforming condition to carburetion and the metal-powder sensitivity that comes off.

When the material of aluminizing was used to prevent carburizing in ethylene gas cracking technology, this technology will be carried out under the reforming temperature that is significantly higher than expection generation carburizing.And carburizing and the metal-powder Cheng Qiwei problem seldom or never that comes off in the reforming process formerly.

Therefore, solve another way that carburizing and metal-powder come off relate to will be thin aluminium or pellumina be added in this reactor assembly at least the metallic surface part on, perhaps at least with aluminizing the metallic surface part of material as this reactor assembly.In fact, metallic surface (particularly to carburetion and metal-powder come off responsive surface) can be handled according to the sort of mode.Such metallic surface includes, but is not limited to wall of reactor, boiler tube and furnace lining.

When metallized aluminum or pellumina, preferably this film has and the identical thermal expansivity in the metallic surface that is coated (for example soft steel), so that withstand the thermal shocking that occurs and temperature cycle repeatedly in reforming process.This has just prevented the cracking of film and has peeled off, this cracking and peel off and make the metallic surface that is layered on bottom be exposed to the hydrocarbon environment that causes carburetion.

In addition, this film also should have be similar to or surpass in the reforming reactor system architecture the heat conductivity of normally used metal.This aluminium film or pellumina also further should be in the reformation environment, or can not worsen in the well-oxygenated environment relevant with catalyst regeneration, also should not cause the hydrocarbon degradation in this reactor assembly.

Be used for some suitable methods that aluminium film or pellumina are coated on the such metallic surface of similar soft steel are comprised well-known deposition technique.Technology comprises powder and vapor diffusion technology preferably, " Alonizing " technology for example, and this Technology can be from AlonProcessing, Inc., Terrytown, Pa has bought.

In fact, " Alonizing " is a kind of High temperature diffusion technology, and this technology is diffused in a kind of surface of processed metal (for example soft steel of technical grade) aluminium and forms alloy.In this technology, described metal (for example a kind of soft steel) is placed in the sintering cover and puts the mixture of blending aluminium powder form around.Then the sintering cover is obturaged, and be placed in the controlled atmosphere furnace.At high temperature aluminium is diffused into dearly and has formed a kind of alloy in the processed metal.After the stove cooling, substrate is taken out from the sintering cover, and remove unnecessary powder.Can straighten as required then, leveling, bevelling and other accessory operations.This technology can make processed (" Alonized ") metal have the performance that impervious carbon and anti-metal-powder come off under low-sulfur reforming condition of the present invention.

Chromium or chromium oxide film also can be used for the metallic surface of coating reaction device system, so that make this surface have the performance of impervious carbon under the low-sulfur reforming condition.Aluminum oxide and aluminium film and the material of aluminizing are similar with using, can not be with the carburizing problem that solves under the low-sulfur reforming condition with the metallic surface of the oxide compound coating of chromium or chromium.

Chromium or chromic oxide also can be used for coating to carburizing and metal-powder come off responsive metallic surface, for example wall of reactor, furnace lining and boiler tube.Yet, in system, demonstrate come off any surface of sign of carburizing and metal-powder and all will have benefited from application chromium and chromium oxide film.

When using chromium or chromium oxide film as coating material, chromium or chromium oxide film preferably have and thermal expansivity like the metal species that coats.In addition, this chromium or chromium oxide film common thermal shocking and temperature cycle repeatedly in also should the ability reforming process.This has just been avoided the cracking of chromium or chromium oxide film or has peeled off, and this cracking or peel off potential and the metallic surface of shop fixtures may be exposed to causing the environment of carburetion.In addition, this chromium or chromium oxide film also should have and be similar to or surpass in reforming reactor system (particularly soft steel) heat-conductive characteristic of employed those materials usually, so that keep sufficient amount of heat transfer.Chromium or chromium oxide film also should not decompose in reformation environment or the well-oxygenated environment relevant with catalyst regeneration, and it also should not cause hydrocarbon degradation in reactor assembly.

Be used for chromium or chromium oxide film are coated to the surface, for example the method on the soft steel comprises well-known deposition technique.Be preferably technology that people select for use and comprise that powder fills and vapor diffusion technology, " chromaking " technology for example, this Technology can be from Alloy Surfaces, Inc., of Wilmington, Dalaware has bought.

" chromaking " technology comes down to a kind of chromium to be coated on vapor diffusion technology (being similar to above-mentioned " Alonizing " technology) on a kind of metallic surface.This technology relates to makes the metal of preparing to coat contact with the chromium powder end, carries out thermodiffusion then.In fact the result of Chu Liing has formed a kind of alloy of chromium and metal to be treated like this, and makes this surface present the performance that extremely strong impervious carbon and anti-metal-powder come off under the low-sulfur reforming condition.

In some zone of this reactor assembly, partial temperature may become very high (for example 900-1250 °F), in boiler tube, and especially true on catalytic bed.In the coke grain that occurs usually, occurring heat release demethanizing reaction on the catalytic bed, form local hot spots.When still preferentially selecting soft steel and rich nickelalloy for use at present, 300 series stainless steels show coking and metal-powder obscission to a certain degree really in the time of about 1000 °F.Therefore, although be useful, 300 series stainless steels still are not the materials that is used for the best of the present invention.

Rich Chromium Stainless Steel, 446 and No. 430 steel for example, its anti-carburizing can be more much higher than 300 series stainless steels.Yet these steel neither ideal (they are tending towards becoming fragile) with regard to resistance toheat.

The material that has performance such as impervious carbon from those that are used for that preferred, effect of the present invention is better than 300 series stainless steels comprises copper, tin, arsenic, antimony, bismuth, chromium and brass, and intermetallic compound and their alloy (for example copper-tin alloy, copper-antimony alloy, stannide, stibnide, bismuthide, or the like).The steel that contains these metals, even also comprise the rich nickelalloy that contains these metals, also show and can reduce carburetion.In a preferred embodiment, these materials are used as plated material, coating material, the material that applies on coating (for example oxide paint) or other the basad structured materials.Why this has special advantage, is because traditional structured material (for example soft steel) still can use, and just needs handling with the contacted surface of hydro carbons.In these materials, standard cubic feet per day is not preferentially selected for use for people because it can with surface reaction, form a kind of at high temperature have fabulous anti-carburizing can coating, and it can resist the coating decortication and peels off.In addition, it is believed that containing tin coating can be thinned to 1/10 micron and still can prevent carburizing.

In the occasion of using, these materials with resistance preferably are coated in a kind of new or existing reactors system with the preparation (hereinafter referred to as " coating ") of the form of similar coating.A kind of like this coating can adopt modes such as spraying, brushing, spot printing to be coated on the surface of reactor assembly, for example on the low-carbon (LC) steel or stainless steel.Preferably decomposable, the active stanniferous coating that responds of such coating, when heating in reducing atmosphere, it is reducible to be active tin and form metal stannide (for example stannide of iron and nickel/iron stannide).

Foregoing coating preferably contains four kinds of compositions (or other functionally similar alternatives) at least: (i) tin compound that can be decomposed by hydrogen, (ii) solvent systems, metallic tin (iii) in small, broken bits and (iv) as the tin-oxide of reductibility moisture absorption/dispersion/tackiness agent.This coating should contain solid in small, broken bits and precipitate to reduce, and should not contain the inactive substance that can stop the surface reaction of active tin and reactor assembly.

As the tin compound that can be decomposed by hydrogen, the ioxynil stannous octoate is useful especially.The commercially available formulation of this compound itself can have been bought on market, and can carry out incomplete drying become the same one deck of almost similar chewing gum, the i.e. one deck that can not peel and/or peel off on a metallic surface.This character all is necessary for the employed composition that applies arbitrarily in this case, because can imagine, this coated material will be stored the several months before handling with hydrogen.And, if before assembling, applied several portions, their finishings in must ability making process so.Such as the above mentioned, the ioxynil stannous octoate can have been bought and reasonable price from the market.This material can be decomposed into an active tin layer lentamente, this tin layer in hydrogen at the low stannide that can form iron under 600 temperature that reaches.

Yet the ioxynil stannous octoate should not use in coating separately, because its not enough thickness.Even when solvent after volatilization wherein, remaining liquid still can drip and drop down or flow on coated surface.For example, in practice, if such thing is used to the horizontal boiler tube of coating, it will converge in the bottom of this pipe.

Composition (iv), the sort of stannic oxide moisture absorption/separation/tackiness agent is a kind of porous sn-containing compound, it can absorb organic metallic tin compound, still also will be reduced to active tin in reducing atmosphere.In addition, tin-oxide can utilize colloidal mill to process, and forms very trickle particle, and such particle can be avoided precipitating rapidly.Adding stannic oxide will provide a kind of grain that is coated with, and this coating becomes one deck as thin as a wafer with drying and can prevent to flow.

Different with coating thickener commonly used, composition (iv) will be selected in this wise: make it can become a kind of part with reactive behavior of coating when reduction.It does not resemble and presents inertia the foregoing silica; Silica then is a kind of coating thickener commonly used, and this thickener becomes a kind of inactive face coat after handling.

Add metallic tin in small, broken bits, promptly composition (iii), metallic tin also can react under alap temperature with the surface of preparing to apply in non-reduced atmosphere to guarantee both to have made.The particle size of tin is preferably 1 to 5 micron, and such particle size can realize aiming at the surperficial fabulous covering of standby metallic tin coating.Non-reduced condition can appear in this coating drying and pipeline connection welding process.It is when partial coating is not reduced as yet fully that the existence of metallic tin has guaranteed both to make, and the tin reaction is still arranged, and form desired stannide layer.

Solvent should be nontoxic, and can be used for that when needed coating is become and can spray and can apply.Solvent also should volatilize and have the solvent properties of the tin compound compatibility of decomposing with available hydrogen rapidly.Preferably select Virahol for use, and if necessary, hexane and pentane can use also.Yet acetone tends to make the organic tin compound precipitation.

In one embodiment, can use the tin coating that contains 20%Tin Ten-Cen (the ioxynil stannous octoate in sad), tin protoxide, metallic tin powder and Virahol formation.

This tin coating can be used in many ways.For example the boiler tube of reactor assembly can apply seriatim, or applies with kit form.According to the present invention, the reforming reactor system can comprise proper width, length and height (the boiler tube assembly (for example about 24 boiler tube assemblies) that for example about 10 feet long approximately are 4 inches wide and about 40 feet high) quantity does not wait.General each assembly will comprise two heads that diameter is suitable, and preferably diameter is about 2 feet, and these assemblies are with the U type pipe coupling of about 4 to 10 suitable lengths (for example about 42 feet long).Therefore, the total area that preparation applies in assembly can in very large range change.For example, in one embodiment, the total area can be about 16500 square feet.

Applicator assembly rather than apply pipe seriatim superiority is arranged aspect four at least: (i) applicator assembly and do not apply the heat collapse that pipe can be avoided tin coating when the moiety of assembly is carried out common thermal treatment in process of production under high temperature seriatim; (ii) applicator assembly is that pipe is faster, cost is lower than applying seriatim equally, and (iii) applicator assembly will be more effective in production process; And (iv) applicator assembly can make solder joint also coated.

Yet, complete applicator assembly can not make the coating effect of pipe resemble one by one to apply.If apply insufficiently, pipe can apply one by one again.

This coating preferably sprays on pipe and the head.Should spray fully so that pipe and well heater are fully coated.After having sprayed an assembly, should its dry about 24 hours, pass to slowly the hydrogen stream of heat (for example under 150 temperature ventilation about 24 hours) then.Then, preferably carry out second time paint spay-coating and in addition dry according to the above program.After applying coating, assembly preferably remains under the lower nitrogen pressure, and before installing, does not allow them stand to surpass about 200 temperature, removes outside the process of measuring moisture, also should not allow them run into water.

The iron content reactive coating also can be used for the present invention.A kind of iron content reactive coating so preferably contains various tin compounds, the quantity that adds iron in the tin compound can reach 1: 3 at most (Fe: Sn, by weight).

For example, can be with Fe ₂O ₃Form add iron.Iron joined have significant advantage, particularly (i) in the stanniferous coating this can make the easier reaction of coating, form the stannide of iron, thereby play fusing assistant; (ii) this can dilute the concentration of nickel in the stannide layer, thereby better anti-coking provide protection is provided; And (iii) this can form a kind of coating, even this coating also can provide the anti-coking provide protection of the stannide of iron under the situation that bottom surface can not react well.

Also have another kind ofly to be used for preventing the method that carburizing, coking and metal-powder come off at the low-sulfur reactor assembly, it is on the rich chromium steel that a kind of metallic coating or covering are added in reactor assembly to be comprised.These metallic coatings or covering may comprise tin, antimony, bismuth or arsenic.Tin is the most desirable.These coatings or covering can adopt following certain methods to apply, and these methods comprise plating, steam deposition and rich chromium steel is flooded in molten metal trough.

It has been found that, in those reforming reactors that are subjected to the serious puzzlement of problems such as carburizing, coking and metal-powder come off, apply rich chromium, contain nickel steel and in fact formed a kind of double shielding layer with one deck tin.Formed the inner rich chromium layer of one deck there, this one deck can impervious carbon, anti-coking and anti-metal-powder come off, and the tin layer of one deck outside, and this one deck also can impervious carbon, anti-coking and anti-metal-powder come off.This phenomenon is to be exposed on common reforming temperature owing to work as the rich chromium steel that applies with tin, and in for example about 1200 following times, it and the reaction of this steel form iron nickel stannide.Thereby nickel is preferentially separated out from the surface of steel, stays after the rich chromium steel layer.In some cases, may need iron nickel stannide layer is removed to expose rich chromium steel layer from stainless steel.

For example, it is found that when the coating layer with tin is added on No. 304 stainless steels and at about 1200 °F down during heating, a kind of rich chromium steel layer can occurs, this one deck contains chromium about 17% and is substantially free of nickel, can compare with No. 430 stainless steels.

When metallic tin being applied or be coated on the rich Chromium Stainless Steel, may need to change the thickness of washing layer or coating layer to obtain the performance that the impervious carbon of ideal, anti-coking and anti-metal-powder come off.For example, this can realize by adjusting the dipping time of rich chromium steel in molten tin bath.This also will influence the thickness of formed rich chromium steel layer.May need to change service temperature, or change the composition of coated rich Chromium Stainless Steel, to control the content of chromium in the rich chromium steel of being produced.

In addition, people have found that the steel that is coated with tin can further be protected the influence that not come off by carburizing, coking and metal-powder by aftertreatment technology.Described aftertreatment technology relates to and coats a thin oxide coating (preferably chromic oxide, for example Cr ₂O ₃) coating.This coating will be very thin, be thinned to and have only several microns.Use so a kind of chromic oxide will under the low-sulfur reforming condition, make aluminising, and the steel (for example Alonized steel) that is coated with tin is protected.

Chromium oxide layer can utilize the whole bag of tricks coating, and these methods comprise chromium-coating hydrochlorate or dichromate coating, subsequently reduces processing; Carry out vapour cure with organo-chromium compound; Perhaps plate layer of metal chromium, the formed chromium plated steel of subsequent oxidation.

The examination of the steel of the eleetrotinplate of one-period low-sulfur reforming condition shows to living through roughly, when forming chromium oxide layer at the stannide laminar surface or under the tin layer, this chromium oxide layer can't destroy the stannide layer, but makes steel further have the performance that impervious carbon, anti-coking and anti-metal-powder come off.Therefore, chromium oxide layer is coated in the steel of being made on steel tin coating or coated with aluminum and has the performance that further impervious carbon, anti-coking and anti-metal-powder come off under the low-sulfur reforming condition.This aftertreatment technology has special using value for handling those through the eligible for repair steel that is coated with tin or aluminising of long-term exposure under the low-sulfur reforming condition.

People also further find, under present low-sulfur reforming condition, have anti-carburizing can Aluminium Coated Steel, " Alonized " steel for example by with tin coating it being carried out aftertreatment, can make it further to show the anti-carburizing energy.This has just formed a kind of steel, because from aluminium coat and the two anti-carburizing that is obtained energy cumulative of coated with tin result, this steel has stronger anti-carburizing energy.This aftertreatment provides extra benefit, and it can make aluminum coating up, as defective or the crackle in " Alonized " coating.In addition, such aftertreatment also will make cost reduce, and prepare to carry out on the surface of steel of aftertreatment with the tin overlay because can be coated with the back with thin aluminium overlay.In addition, this aftertreatment will protect because the bottom steel that bending exposed of Aluminium Coated Steel, and this bending may crack and make steel to be subjected to the harm of the carburetion that produced under the condition of reorganization on the aluminium lamination.In addition, this aftertreatment technology can also prevent to form coking on the surface of processed steel, and prevents from plating aluminium but further be not coated with the coking that the bottom of the crackle that occurs on the steel of tin forms.

The sample that it is found that " Alonized " that apply with tin in a side demonstrates under the low-sulfur reforming condition only has black coke deposition in a untreated side.The coke that forms at aluminium plated surface is because the optimum coking that the cracking on the acidic alumina position causes.This can not cause further coke deposition.Therefore, this aftertreatment at the coat that adds tin on the aluminized steel can further reduce problems such as the carburizing, coking and the metal-powder that occur in the reactor assembly that moves come off under the condition of reorganization of the present invention.

Under the situation of not wishing bound by theory, it is believed that for the present invention, the suitability of various materials can be selected and according to them the reaction of carburizing environment be classified.For example, iron, cobalt and nickel form the carbide of rather unstable, and and then these carbide carburizing, coking and metal-powder will occur and come off.Resemble the such element of chromium, niobium, vanadium, tungsten, molybdenum, tantalum and zirconium and will form stable carbide, these carbide have the performance that stronger impervious carbon, anti-coking and anti-metal-powder come off.Resemble tin, antimony and bismuth and do not form carbide or coke.And these compounds can form stable compound with many metals (for example iron, nickel and copper) under the condition of reorganization.The compound of stannide, stibnide and bismuthide and lead, mercury, arsenic, germanium, indium, tellurium, selenium, thallium, sulphur and oxygen also has resistance.A last class material comprises and resembles silver, copper, gold, the such element of platinum, and resembles silicon oxide and the such refractory material of aluminum oxide.These materials have anti-carburizing and do not form carbide in carburizing environment under the condition of reorganization, or different other metal reactions.

As discussed above, select to have the come off suitable metal of performance and be a kind of method of preventing that carburizing and the metal-powder problem that comes off from occurring of being used to as the coating material of metallic surface in reactor assembly of impervious carbon and anti-metal-powder to them.Yet it is ubiquitous that carburizing and metal-powder come off in miscellaneous metal; And impervious carbon material is compared with the higher or more difficult acquisition of cost employed traditional material (for example soft steel) in the structure of reforming reactor system.Therefore, may need to use stupalith in reactor assembly of the present invention, this material does not form carbide under common the condition of reorganization, and therefore is not subjected to the influence of carburetion yet, is like this for a part of metallic surface in the reactor assembly at least.For example, at least a portion boiler tube or furnace lining or the two are made with stupalith possibly.

When selecting to be used for stupalith of the present invention, this stupalith preferably has and is equivalent to or is higher than the heat conductivity of employed those materials in the structure of reforming reactor system usually.In addition, these stupaliths also should have enough structural strengths under the temperature that occurs among the reforming reactor system.These stupaliths are the further thermal shocking that occurs in the reactor assembly operation process of ability and temperature cycle repeatedly also.When stupalith was used for making furnace lining, this stupalith should have the hot expansibility that is equivalent to the outer metallic surface that directly contacts with furnace lining.The too big stress at tieing place in this temperature cycle process of just having avoided in driving and docking process, occurring.In addition, ceramic surface is difficult for taking place aging in the hydro carbons environment or in the well-oxygenated environment that occurs in catalyst regeneration process.Also should be unable to the induce reaction degraded of the hydro carbons in the device system of selected stupalith.

The stupalith that is suitable for includes, but is not limited to the material of silicon carbide, silicon oxide, silicon nitride and aluminium nitride and so on.In the middle of these materials, silicon carbide and silicon nitride are the most desirable, because they can provide comprehensive protection to reactor assembly under the low-sulfur reforming condition.

At least a part of metallic surface in the reactor assembly also can silicon-coating or silicon oxide film.Particularly the metallic surface that can apply includes, but is not limited to wall of reactor, boiler tube and furnace lining.Yet, in reactor assembly, under the low-sulfur reforming condition, demonstrate the come off metallic surface Anywhere of sign of carburizing and metal-powder and all can have benefited from coating film silicon fiml or silicon oxide film.

Can use traditional method that silicon or silicon oxide film are coated on the metallic surface.Silicon or silicon oxide can utilize electrochemical plating and in the steam carrier gas chemical Vapor deposition process of organoalkoxysilane apply.Silicon or silicon oxide film preferably have and its much the same thermal expansivity in coated metallic surface.In addition, silicon or silicon oxide film also should be able to tolerate the thermal shocking that occurs and temperature cycle repeatedly in reforming process.This has just been avoided the cracking of silicon or silicon oxide film and has peeled off, and has avoided the underlying metal surface is exposed to the potential possibility of the hydro carbons environment that causes carburetion.Silicon or silicon oxide film also should have the heat conductivity that is equivalent to or surpasses the metal that is generally used for the reforming reactor system, so that keep sufficient amount of heat transfer.Silicon or silicon oxide film should be not aging in the reformation environment or in the well-oxygenated environment relevant with catalyst regeneration yet; It also should not cause the degraded of hydro carbons self.

Because zones (for example different zone in the stove) different in the reactor assembly of the present invention may be exposed in the very wide temperature range, also in addition classification of the selection of material so, so as with those can provide better anti-carburizing can material be used for system those stand the zone of top temperature.

Selection about material it is found that, the 8th oxidized family's metallic surface (for example surface of iron, nickel and cobalt) is not having oxidized metallic surface to have stronger activity than corresponding aspect coking and the carburizing.For example, it is found that it is high that a kind of sample of the more inoxidized same steel of activity of No. 347 stainless steel samples of process air roasting is wanted significantly.It is believed that this is because oxidized restoring of steel produced superfine short grained metallic iron and/or nickel.Such metal is especially responsive for carburizing and coking.Therefore, in reclaiming process (for example normally used those technologies in the catalytic reforming) process of oxidisability, to avoid using these materials as much as possible.Yet people have found that 300 series stainless steels through air roasting that are coated with tin also can have and same similar impervious carbon of the unfired sample that covers tin 300 series stainless steels and anti-coking performance.

In addition, people will appreciate that, in that irrelevant and sulphur is to be used to make in those systems of metal surface passivation to the susceptibility of sulphur with catalyzer, oxidation also will be a problem.If the amount of sulphur is in a single day insufficient in more such systems, any metallic sulfide that forms in the metallic surface all is reduced to metallic particles in small, broken bits after oxidation and reduction.This metal can have the coking and the carburizing activity of height.This might cause catastrophic accident in metallurgy aspect or great coking incident.

As mentioned above, when the demethanizing reaction of the heat release among the coke grain causes local hot spots, on catalytic bed ultrahigh-temperature may appear.These focuses also can throw into question in traditional reforming reactor system (and other chemical technologies and petrochemical processes field).

For example, the pipe core of having observed reformer sieves local damage and produces hole; Cause catalyst loss the most at last.In traditional reforming process, the suitable height of temperature in formation and combustion processes between coke grain is enough to offset the ability that sulphur inhibition coking, carburizing and powder come off in the technological process.Therefore, carburizing and more responsive to the damage that is caused owing to intercrystalline oxygenizement (a kind of form of corrosion) in the regenerative process will take place in metallic screen.Sieve aperture enlarges, and hole has also been expanded.

Therefore, instruction of the present invention can be applicable to traditional reforming process, also can be applicable to the other field of chemical technology and petrochemical processes.For example, foregoing plating, coating and coating can be used for manufacturing center's pipe sieve, with the undue expansion of avoiding sieve aperture and the loss of catalyzer.In addition, this instruction can also be used to be subjected to the boiler tube arbitrarily of the harm that carburizing, coking and metal-powder come off, for example boiler tube in the coking furnace.

They in addition,, those technology described here come off, so also can be used for the pyrolyzer that moves under about 1400 to 1700 temperature because can being used for being controlled under the ultra high temp carburizing, coking and the metal-powder that occur.For example, can be controlled at the damage of the steel that occurs in the pyrolyzer that moves under those temperature by applying various metallic paint.These metallic paint can adopt the mode of fusion, plating and coating to use.Application pattern is particularly desirable.

For example, antimony plating material is coated to the influence that can protect these steel not come off by carburizing, coking and metal-powder on the iron content steel under described cracking condition.In fact, be coated in the provide protection that the antimony coating on the iron content steel will provide impervious carbon, anti-coking and anti-metal-powder to come off under 1600 temperature.

The bismuth coating that is coated onto on the rich nickel steel alloy (for example Inconel 600) can protect those steel to avoid the harm that carburizing under cracking condition, coking and metal-powder come off.This confirms under up to 1600 temperature.

The provide protection that provides impervious carbon, anti-coking and anti-metal-powder to come off on the iron content steel and under cracking condition also can be provided bismuth coating.In addition, can also use the metallic paint of forming by bismuth, antimony and/or tin.

Again have a look at the low-sulfur reforming process again, the problem that also can use some other technology to solve to be found according to the present invention.They can use with the suitable material of selecting for this reactor assembly, perhaps also can use separately.The selected best approach is impervious carbon and the anti-coking reagent that adds non-sulphur in reforming process in these additional technology.These reagent can be in technological process add continuously, and match with those surfaces of the reactor assembly that contacts hydro carbons and to work, and perhaps they can be coated onto on the reactor assembly in pretreated mode.

Under the situation of not wishing to be bound by theory, it is believed that these reagent by decompose and the surface chemistry etch and with the surface interaction of reactor assembly, form the intermetallic compound of iron and/or nickel, for example stannide, stibnide, bismuthide, leadization thing, arsenide etc.These intermetallic compounds have the performance that impervious carbon, anti-coking and anti-metal-powder come off and can protect underlying metal.

People believe that also these intermetallic compounds are more stable than formed metallic sulfide in the system that uses the hydrogen sulfide passive metal.These compounds can not be by hydrogen reduction as metallic sulfide.As a result, they are littler than possibility that metallic sulfide breaks away from this system.Therefore, the carburizing inhibitor that adds continuously together with raw material can be minimized.

Comparatively desirable impervious carbon of non-sulphur and anti-coking reagent comprise organometallic compound, for example organo-tin compound, organo-antimony compound, bismuth organic compound, organoarsenium compound and organo-lead compound.The organo-lead compound that is fit to comprises tetraethyllead and tetramethyl plumbane.Organo-tin compound, for example tetrabutyl tin and tin trimethyl hydride are particularly desirable.

Other specific organometallic compounds comprise neodecanoic acid bismuth, sad chromium, copper naphthenate, manganese carboxylate, neodecanoic acid palladium, neodecanoic acid silver, tetrabutyl germanium, tributyl antimony, antimony triphenyl, arsenic triphenyl and zirconium caprylate.

These reagent are added reactor assembly how and when not strict, depends primarily on concrete technological design characteristic.For example, they can add continuously or add discontinuously with material.

Yet it is worthless that this reagent is added in the material, because they may accumulate in the part that reactor assembly begins, like this may not can provide sufficient provide protection to other parts of reactor assembly.

This reagent preferably before making, drive before or at the scene (promptly in existing systems) provide with the form of coating.If add at the scene, should behind catalyst regeneration, carry out at once.Can be coated with extremely thin coating.For example, it is believed that when using organic tin compound, the stannide that approaches the iron that reaches 0.1 micron is still very effective.

In existing or new reactor surface, or on the surface new or existing boiler tube the coating this reagent a kind of comparatively desirable way a kind of organometallic compound is decomposed in hydrogen environment under about 900 °F.For example, for organo-tin compound, so just on the surface of pipe, generate reactive metal tin.Tin will be further and the metal reaction on surface under such temperature, makes its passivation.

If it is the mixture that the ideal words depend on compound that best application temperature will depend on concrete organometallic compound or alloy.Usually, excessive organo-metallic coating reagent can be imported in the pipe, so that coating reagent is passed system with the form of aerosol with pulse mode under the high hydrogen flow rate.Then, can reduce flow velocity, so that the paint metal mist is coated on boiler tube or the reactor surface and reaction with it.In other words, this compound can be introduced with the steam form, and this steam can decompose in the reductibility environment and react with the hot wall of pipe or reactor.

As discussed above like that, carburizing, metal-powder are come off and the reforming reactor system of coking sensitivity can be by being handled to this reactor assembly the decomposable applying coating that contains decomposable organo-metallic tin compound to those the most responsive regional modes of carburetion.A kind of method is like this worked well especially in the stove of having controlled temperature.

Yet such control does not always exist.In reactor assembly, particularly in boiler tube, " focus " appears.At these focuses, organometallic compound can decompose and form settling.Therefore, another aspect of the present invention is a kind of technology, and this technology has avoided not having strictness to control and demonstrate such deposition in the reforming reactor system of high temperature hotspot in temperature.

A kind of technology like this comprises with hot hydrogen stream carries out preheating to the whole reactor system, and temperature reaches 750 °F to 1150 °F, is preferably 900 °F to 1000 °F, is preferably about 1050 °F.After the preheating, contain the organo-tin compound of gasification and the colder air-flow of hydrogen is 400 °F to 800 °F in temperature with one, be preferably 500 °F to 700 °F, be preferably the reactor assembly of sending under about 550 condition through preheating.This gaseous mixture is introduced into the upstream and a kind of decomposition " ripple " can be provided, and the whole reactor system is spread all in this decomposition " ripple ".

In fact this technology is because hot hydrogen has produced by the surface of even heating, and this surface will make colder organic metal gas decompose when it spreads all over the whole reactor system with the form of ripple.The colder gas that contains the organo-metallic tin compound will decompose on the hot surface and be coated on this surface.The steam of organo-metallic tin will move with the form of ripple continuously so that handle the surface of heat in the downstream of this reactor assembly.So the whole reactor system just can have the uniform coating of organo-metallic tin compound.Do so also may be ideal: these cold one hot temperature cycle are carried out several times apply the organo-metallic tin compound to guarantee that the whole reactor system is coated with equably.

In the operational process of reforming reactor according to the present invention system, petroleum naphtha will be examined into aromatic hydrocarbons by reformation.Feed naphtha is a kind of light hydrocarbon, and its boiling point distribution range is preferably about 70 °F to 450 °F, more preferably about 100 °F to 350 °F.Feed naphtha will include hydro carbons aliphatic or that alkane belongs to.These aliphatic hydrocarbons have at least a part to be converted into aromatic hydrocarbons in the reforming reaction district.

In " low-sulfur " of the present invention system, material preferably contains the sulphur that is less than 100ppb, is more preferably the sulphur that is less than 50ppb.If necessary, can utilize a kind of sulphur adsorption layer unit to remove a small amount of excessive sulphur.

Desirable reforming process condition comprises that temperature is 700 to 1050 °F, more preferably 850 to 1025 °F; Pressure is 0 to 400 pound/square inch, more preferably 15 to 150 pounds/square inch; It is 0.1 to 20 that the flow velocity of recycle hydrogen is enough to make hydrogen and the hydrocarbon polymer mol ratio of sending into the reforming reaction district, more preferably 0.5 to 10; And the liquid space velocity in per hour of the hydrocarbon material by reforming catalyst is 0.1 to 10, is preferably 0.5 to 5.

In order to obtain suitable reforming temperature, boiler tube must be heated to high temperature usually.The distribution range of this temperature can be 600 to 800 °F usually, and more common is 850 to 1250 °F, more commonly 900 to 1200 °F.

As previously discussed, have found that, carburizing in the low-sulfur system, coking and the metal-powder problem that comes off is relevant with the local too high technological temperature of reactor assembly, and causes harm especially in the boiler tube of this system, in these boiler tubes temperature high especially be its distinctive feature.Generally reach as high as 1175 °F when the temperature on boiler tube surface is at end of run in the high traditional reforming process technology of sulfur-bearing.Yet undue carburizing, coking and metal-powder obscission have not been observed.Yet, in the low-sulfur system, it has been found that intensive to have occurred and carburizing rapidly, coking and metal-powder come off, occur in for the above-mentioned phenomenon of CrMo steel to be higher than under 956 temperature, occur in for stainless steel and be higher than under 1025 the temperature.

Therefore, another aspect of the present invention is that temperature with the metallic surface in boiler tube, line of pipes and/or the reactor of this reforming system is reduced to noted earlier below horizontal.For example, can utilize attached to the thermopair of different sites in this reactor assembly and controlled.In boiler tube, thermopair can outer wall attached to them on, preferably the hottest point of stove the outlet of stove (usually near).In case of necessity, can in technological process, regulate, keep temperature to be in the ideal level.

The surface that also has some other technology also to can be used to reduce system is exposed under the disadvantageous high temperature.For example, heat transfer area can be used resistant to elevated temperatures (also being that cost is higher usually) pipeline in the highest final section of its typical temperature.

In addition, can between each reactor of reforming system, charge into superheated hydrogen.Also can adopt bigger loaded catalyst.And catalyzer can be regenerated more frequently.About catalyst regeneration, preferably utilize moving bed process to finish, in moving bed process, catalyzer takes out from last bed, and regeneration is inserted first then.

In low-sulfur reforming reactor assembly of the present invention, also can utilize the equipment configuration of certain other novelty and processing condition that carburizing and metal-powder are come off and be reduced to bottom line.For example, reactor assembly can be made of fractionated well heater and/or pipeline.In other words, in reactor assembly, bear the well heater of the harshest temperature condition and pipe can with anti-carburizing can employed material property be higher in the structure of reforming reactor system usually the material manufacturing, these materials are just as previously discussed.Those well heaters and the pipe that do not bear the severe temperature condition can continue with traditional material manufacturing.

By in reactor assembly, utilizing so a kind of fractionated design, might reduce the resulting cost (generally the material than traditional is expensive because of impervious carbon material) of this system and still can obtain a kind of come off reactor assembly of performance of enough impervious carbon and anti-metal-powder that under the low-sulfur reforming condition, has.In addition, this will reequip existing reforming reactor system at an easy rate so that they can have the performance that impervious carbon and anti-metal-powder come off under the low-sulfur operational condition, because this reactor assembly has only fewer part need utilize grading design to replace or improve.

This reactor assembly can also utilize at least two temperature ranges (interval that at least one temperature is higher and the interval that temperature is lower) to operate.This treating method is based on a kind of like this observation, and promptly metal-powder comes off and has temperature maximum value and minimum value, and metal-powder comes off and can be reduced to minimum level when being higher than maximum value and being lower than minimum value.Therefore, " higher " temperature refers to temperature and is higher than in the reforming reactor system normally used temperature and is higher than and the metal-powder the most serious temperature that comes off occurs." lower " temperature refer to temperature or be approximately the common temperature that adopts of reforming process and be lower than and metal-powder occurs and come off and become the temperature of a problem.

Make the some parts of reactor assembly will reduce metal-powder and come off, because have only less reactor assembly to be in the temperature that causes that metal-powder comes off in different temperature range work.In addition, a kind of so some other advantage of design comprises owing to the some parts that makes reactor assembly is worked under higher temperature and improved heat transfer efficiencies and reduced equipment size.Yet the some parts that makes reactor assembly is being lower than and is being higher than that causing works under the temperature that metal-powder comes off can only be reduced to bottom line the temperature range that metal-powder comes off occurring, but can not avoid fully.Why this can not be avoided is owing to temperature fluctuation will occur in one day another day operational process of reforming reactor system, the particularly temperature fluctuation that in this system shutdown or startup procedure, is occurred, the temperature fluctuation that in working cycle, is occurred and the temperature fluctuation that when process fluid heats in reactor assembly, will occur.

Metal-powder come off reduce to MIN another kind of way and relate to and utilize superheated raw material (for example hydrogen), so just can be reduced to bottom line to demand by the furnace wall heated hydrocarbon to system's heat supply.

In addition, a kind of former reforming reactor system with big caliber and/or higher pipe flow speed that pre-exists that provides is provided another kind of technological design mode.Utilize big caliber and/or higher pipe flow speed will be exposed to the heating surface of reactor assembly the chance reduction of hydro carbons, to bottom line.

As mentioned above, catalytic reforming is well-known in petroleum industry, and it relates to by the mode that produces aromatic hydrocarbons handles the petroleum naphtha fraction to improve its octane value.The important hydrocarbon reaction that occurs in the resurfacing operation process comprises that cyclohexane dehydrogenation is that aromatic hydrocarbons, alkyl cyclopentane dehydroisomerization turn to aromatic hydrocarbons and acyclic hydro carbons dehydrocyclization is an aromatic hydrocarbons.In addition, the other reaction also appears, comprise that alkylbenzene takes off alkyl, isomerization of paraffinic hydrocarbons and some hydrocracking reactions, hydrocracking reaction produces some light, gasiform hydro carbons, for example methane, ethane, propane and butane, and hydrocracking reaction should be minimized in reforming process, because they have reduced the yield of gasoline ebullient product and hydrogen.Therefore, employed here " reformation " refers to by the reaction that utilizes one or more generation aromatic hydrocarbons and comes the handle hydrocarbon raw material, so that a kind of product (being the product that a kind of aromaticity content is higher than raw material) that is rich in aromatic hydrocarbons is provided.

And the present invention relates generally to catalytic reforming, and it is often used in utilizing under the low-sulfur condition various hydrocarbon raw materials to produce aromatic hydrocarbons.In other words, catalytic reforming is meant that generally petroleum naphtha transforms, and other raw material also can be handled the product that perfume compound is rich in generation.Therefore, when transforming petroleum naphtha as a preferred embodiment, the present invention is very useful for making various feedstock conversion or aromatization aspect, and these raw materials are paraffinic hydrocarbons, alkene, alkynes, cycloalkanes, cycloolefin and their mixture for example, particularly saturated hydro carbons.

The example of paraffinic hydrocarbons is those hydrocarbon with 6 to 10 carbon atoms, for example normal hexane, methylpentane, normal heptane, methyl hexane, dimethylpentane and octanes.The example of alkynes is those hydrocarbon with 6 to 10 carbon atoms, for example hexin, heptane and octynes.The example of naphthenic hydrocarbon is the hydrocarbon of those 6 to 10 carbon atoms, for example methylcyclopentane, hexanaphthene, methylcyclohexane and dimethyl cyclohexane.The typical example of cycloolefin is that those have 6 to 10 carbon atoms, for example methyl cyclopentene, tetrahydrobenzene, tetrahydrotoluene and dimethyl tetrahydrobenzene.

The present invention also is of great use for utilizing various reforming catalyst to reform under the low-sulfur condition.Such catalyzer comprises (but being not limited to) attached to the 8th family's precious metal on the high-temperature inorganic oxide, for example the platinum on the silica, the Pt/SN on the silica and the Pt/Re on the silica; The 8th family's precious metal on the zeolite, for example Pt on the zeolite, Pt/SN and Pt/Re, zeolite is L-zeolite, ZSM-5 for example, silication type and β type; With the 8th family's precious metal on the L-zeolite of basic metal and alkaline-earth metal exchange.

A preferred embodiment of the present invention relates to uses the macroporous zeolite catalyst that includes a kind of basic metal or alkaline-earth metal and be filled with one or more the 8th family metals.The most desirable embodiment is the embodiment that therein a kind of like this catalyzer is used for the reformed naphtha raw material.

The zeolite that the general expression of " macrovoid " this speech has the active porosity size of 6 to 15 dusts.Be used for comparatively desirable macrovoid crystal zeolite of the present invention and comprise zeolite L, X type zeolite, y-type zeolite and faujusite.These zeolites have the apparent pore dimension of 7 to the 9 dust orders of magnitude.The most desirable zeolite is a zeolite L.

Can be with following formulate with the composition of the zeolite L of the formal representation of oxide mol ratio:

(0.9-1.3) M ₂/ _nO: Al ₂O ₃(5.2-6.9) SiO ₂: yH ₂O is in above formula, and M represents positively charged ion, and n represents the valency of M, and y can be 0 to about 9 arbitrary value.Zeolite L, its X-ray diffraction figure, its performance and its preparation method for example are described in detail in United States Patent (USP) 3216789, and its content is here quoted as a reference.Existing formula can be changed under the prerequisite that does not change crystalline structure.For example, the mol ratio of silicon and aluminium (Si/Al) can change to 3.5 by 1.0.

Chemical formula with the y-type zeolite of the formal representation of the mol ratio of oxide compound can be write:

(0.7-1.1) Na ₂O: Al ₂O ₃: xSiO ₂: yH ₂O in above formula, X be one greater than 3, be about 6 value to the maximum.Y is one and is about 9 value to the maximum.Y-type zeolite has distinctive X-ray powder diffraction figure, and this figure can be used for differentiating according to above formula.Y-type zeolite has more detailed record in United States Patent (USP) 3130007, its content here is cited as a reference.

X type zeolite is a kind of crystal zeolite molecular sieve of synthetic, and it can use following formulate:

(0.7-1.1) M ₂/ _nO: Al ₂O ₃: (2.0-3.0) SiO ₂: yH ₂O is in above formula, and M represents a kind of metal, is a kind of basic metal or alkaline-earth metal specifically, and n is the valency of M, and Y is up to 8 arbitrary value, and this depends on the person's character of M and the hydration levels of this crystal zeolite.X type zeolite, its X-ray diffraction figure, its character with and preparation method thereof detailed record is arranged in United States Patent (USP) 2882244, its content here is cited as a reference.

In the macrovoid zeolite, preferably contain basic metal or alkaline-earth metal.The sort of alkaline-earth metal can be barium, strontium or calcium, preferably barium.Can adopt synthetic method, pickling process or ion exchange method that alkaline-earth metal is mixed in the zeolite.Barium is why more desirable than other alkaline-earth metal to be because it can form a kind of slightly tart catalyzer.Strongly-acid is worthless in catalyzer, because it promotes cracking, selectivity is reduced.

In another embodiment, have at least part basic metal can utilize known zeolite ion exchange technique to be exchanged with barium.This comprises makes zeolite and contains excessive B _a ⁺⁺Ion solution contacts.In this embodiment, the content of barium is preferably by 0.1% to 35% (by the weight of zeolite).

Macrovoid zeolite catalyst used in the present invention is filled with one or more the 8th family metal, for example nickel, calcium, rhodium, palladium, iridium or platinum.The 8th comparatively desirable family's metal is an iridium, particularly platinum.These metals have the selectivity of stronger dehydrocyclization and more stable under the dehydrocyclization reaction conditions than other the 8th family's metal.If you are using, platinum preferable weight percent content in catalyzer is 0.1% to 5%.

The 8th family's metal mixed to adopt synthesis method, pickling process in the macrovoid zeolite or in the aqueous solution of suitable salt, exchange.When needs mixed zeolite with two kind of the 8th family's metal, operation can be carried out simultaneously, also can carry out in proper order.

More fully to understand purpose of the present invention in order reaching, to provide following example some aspect of the present invention is described.Yet, should be realized that, in any case the present invention is not limited to listed concrete details here.

Example 1

Do the influence of some test open fires and silicon to the carburizing in the reformation reactor assembly.

In these trials, some eight inches copper pipes long, 1/4 inch external diameter are used as carburizing and the embrittlement of reactor to study No. 347 Stainless Steel Wires.These diameters are to have in the three velamen tubular stingers in 0.035 inch the Stainless Steel Wire, and pipe has 4 inches long parts to be remained on by a stove under 1250 the uniform temperature.The pressure of system remains 50 pounds/square inch.With the flow velocity of hexane with 25 microlitres/minute (1.5 milliliters/hour), hydrogen is introduced reactor with the flow velocity of 25 ml/min (hydrogen is 5: 1 with the ratio of hydrocarbon) simultaneously.Measure methane the existing in the product gas flow with definite heat release methane reaction.

What utilization contained the sulphur that is lower than 0.2ppm is that pure hexane carries out controlled trial basically.Only just find after three hours that pipe has been full of carbon fully.This not only makes the flow disruption of hydrogen and hexane material, and the carbon that generates does pipe to have split unexpectedly, and has produced projection in reactor.The content of the methane in product stream before stopping up near 60-80% weight.

Another test is to carry out in substantially the same condition, the different sulphur that has just added 10ppm.This test was interrupted before checking steel wire at it and has continued 50 hours.Do not find that in process of the test methane content increases.It is stable that the thermo-cracking methane content keeps, and was approximately for 16% (by weight).Do not find the coke tamper, do not observe the carburizing phenomenon of steel wire yet.

Carry out another identical test, the different sulphur that has just only added 1ppm (be previous test 1/10th).This test shows had a small amount of methane to generate, or slight obstruction is arranged after 48 hours.Inspection to steel wire shows that a small amount of surface carbon is arranged, but does not have large-scale carbon to produce.

Carry out another test, just in hexane, added the water of 1000ppm (0.1%) with the form of formic acid.Test has been carried out 16 hours, does not occur stopping up in reactor.Yet, when pipe is done to split, find to have 50% pipe to be full of carbon.But the accumulation of carbon is so serious far away from controlled trial.

Example 2

Carry out some tests to determine to be fit to be applied to the material of low-sulfur reforming reactor assembly, these materials should have than being generally used for the better anti-carburizing energy of low-sulfur reforming processes soft steel.

In these trials, used a kind of device, this device comprises a Lindberg alumina tube furnace, with a thermopair that is placed on tube exterior in the hot-zone, temperature is controlled in the scope of 1 degree.The internal diameter of boiler tube is 5/8 inch.Test several times at the thermopair that is suspended in under 1200 the given temperature among the pipe hot-zone (about 2 inches).This internal heat galvanic couple is measured temperature with keeping, and measured temperature records low 0 to 10 °F than external heat galvanic couple.

Simulation under the condition of exposing material under the low-sulfur reforming condition to the test 24 hours under 1100,1150 and 1200 temperature of soft steel (C steel and 2 1/4Cr steel) sample and 300 series stainless steels, and 1100 tests 90 hours down.The sample of various materials all is placed on the opening quartz boat that is arranged among the boiler tube hot-zone.1 inch of quartz boat is long, and 1/2 inch wide, is placed in well among 2 inches hot-zones of pipe.Quartz boat is put at every turn and is taken out all and joins with quartz glass bar.In the time of in quartz boat is placed on pipe, do not use the internal heat galvanic couple.

Before on-test, pipe nitrogen purging several minutes.The commercially available bottled hydrogen mixture carburetted gas that contains 7% propane at room temperature poured into the bottle that contains toluene by 1 liter contain 1% the toluene of having an appointment in the material gas mixture so that make.Keeping air-flow in this device is 25 to 30 ml/min, and pressure is barometric point.Sample rises to service temperature with 144/minute speed.

Material is being exposed under desired temperature after carburizing gas reaches required time, device is with being added in stove air outside air-flow chilling.When device fully after the cooling, with the nitrogen purging hydrocarbon gas and take out quartz boat and check and analyze.

Before beginning, test materials is cut into the size and dimension of with the naked eye identifying easily.In pre-treatment arbitrarily, for example after cleaning or the roasting, with samples weighing.Most of samples are less than 300 milligrams.Generally test at every turn and all in quartz boat, put 3 to 5 samples.Each test all has 347 stainless steel samples as interior mark.

After finishing test each time, the situation that all will carefully observe quartz boat and each material.Generally take a picture to quartz boat.Then, the weight of each material of weighing is preserved all coke settlings with suitable substrate material simultaneously carefully so that measure variation.After rectifying, sample is fixed on the Resins, epoxy, grinding and buffing is prepared for petrographic analysis and scanning electron microscope analysis, and each material comes off to coking, metal-powder and the reaction of carburizing to measure.

As required, the residence time of employed carburetted gas is longer than the general industrial operation in these trials.Therefore, it is believed that test conditions is stricter than industrial condition possibly.Some underproof material is in fact industrial still reliable in these trials.Yet these tests provide the reliable indication of the ability that the relative anti-coking to these materials, impervious carbon and anti-metal-powder come off.

The results are shown in the following form.

Table *

1200 of carbon weightening finish weight % powder dropping structures; 24 hours

C steel 86 is serious

2 1/4Cr 61 are serious

304 seldom do not have 18Cr10Ni

347 seldom do not have 18Cr10Ni1150 °F; 24 hours

C steel 63 is serious

2 1/4Cr 80 are serious

304 1 do not have

347 1 do not have 1100 °F; 24 hours

C steel chip is faint, the part

2 1/4C 0 do not have

304 0 do not have

347 0 do not have 1100 °F; 90 hours

C steel 52 is serious

2 1/4C 62 are serious

304 5 do not have

347 1 no * 15%C ₇H ₈+ 50%C ₃H ₈+ H ₂(by weight).

Certainly, above result is qualitatively, and depends on the roughness on surface, the i.e. microtexture of metal.The autocatalytic surperficial coking of carbon weightening finish representative.

Example 3

More than employed identical technology be used under 1200 temperature multiple material carried out 16 hours extensive screening once more.Below the results are shown in.Each group is illustrated in the quartz boat equality contrast under the same conditions.

Table (1)

Carbon weightening finish % by weight powder come off composition I group Inconel 600 57 serious 15Cr75Ni347 oxidations (2) 21 slight 347 fresh 4 without 18Cr75Ni II group Inconel 600 40 serious 15,Cr7,5Ni,310 8 medium 25Cr20NiIncoloy 800 5 slight 21,Cr3,2Ni,347 1 trace III organize Incoloy 825＜1 slight Haynes 230 2 medium 22Cr64NiAlonized 347 3 traces 347＜1 trace IV organize Ni (pure) 656 serious 100NiCu (pure) 0 without 100CuSn (melting) 100Sn 0 without Tin Can Sn+C steel 0 nothing (1) 15%C₇H ₈+ 50%C ₃H ₈+ H ₂(by weight) (2) under 1000C roasting 2 hours to produce the oxide thin layer thing

Example 4

Utilize other material (in addition explanation except) of engineering test described in the example 2 again.

446 stainless steels and 347 stainless steel samples are put in the example boat and in test 2 weeks altogether in described cementing plant equally under 1100.446 stainless steels have very thin one deck coke, but do not detect other controversial phenomenon.And on the other hand, coke and metal-powder have been filled up in the hole that 347 stainless steels but have a large amount of local coke settlings and the degree of depth to reach 4 mils in these holes, and all projection has been come.

Test is sieved sample with the galvanized carbon steel of tin, silver, copper and chromium.Sample has the coating of about 0.5 mil thick.After having carried out 16 hours carburizing shaker tests under 1200 °F, on zinc-plated and chromium plating sieve, do not form coke.On silver-plated and copper-plated sieve, formed coke, but just in place that coating comes off.To there not being galvanized carbon steel sieve to test as galvanized sieve, the result serious coking, carburizing and metal-powder occur and comes off.

Test the sample of 304 stainless steel sifts; Each sample is with a kind of plating the among tin, silver, copper and the chromium.Sample has the coating of about 0.5 mil thick.After having carried out 16 hours carburizing shaker test under 1200 temperature, any one does not all form coke through on the galvanized sieve, just the part coking occurs in the place of coating foaming decortication on the copper facing sieve.Carrying out having observed the thin layer coke on the not galvanized 304 stainless steel samples of the test identical with the clad sieve of electricity.

Test the sample of 304 stainless steel sifts, each sample is with a kind of plating the among tin and the chromium.These samples carry out cementation test with 446 stainless steel samples under 1100 °F.Sample 5 weeks that were exposed.Once in a week sample is cooled to the room temperature file of observing and take a picture, then they is reheated to 1100 °F.Tinned sieve does not have coke; Chromed sieve does not have coke yet, just coking occurs in the local part that chromium coating comes off; And 446 stainless steel samples are coated with the last layer coke equably.

Under 1200 temperature, the Inconel 600 (75%Ni) of not plating and the sample of zinc-plated (plating) Inconel 600 (75%Ni) are carried out test in 16 hours.Coking and metal-powder obscission appear in zinc-plated sample, just do not reach the sort of degree of not galvanized sample.

Example 5

Carry out following test so that the heat release methanation reaction that occurs in the formation of coke grain and the combustion processes in the reforming process of research under low-sulfur bar ox.In addition, to also being studied as a kind of tin that reduces the additive of methane formation.

In the low-sulfur reforming reactor assembly, have been found that the coke settling of the iron particle that contains fusing, the phenomenon that forms smelting iron in this reforming process under 900 to 1000 temperature it is believed that it is the utmost point strong exothermic reaction that occurs owing in reforming process.It is believed that the approach that has only the high like this temperature of a kind of generation, that is exactly the reaction that generates methane by the heat release intensive.This high temperature makes us feeling surprised especially, generally absorbs heat because reform with regard to its character, and in fact it trend towards making the reactor assembly cooling.High temperature may be created in heat insulation good coke grain inside, and this is to be diffused into the inner iron powder position that katalysis is arranged by hydrogen, and they play katalysis to forming methane by coke and hydrogen at these positions.

In this test, in a micro-test device, utilize steel fiber to study the formation of methane.Restrain steel fiber with 0.14 and fill one 1/4 inch stainless steel tube, and it is placed in the stove at 1175 at a place.Make hexane and hydrogen carry out raw material and product analysis by iron and to effluent.Steel fiber carried out 20 hours pre-treatment with hydrogen before feeding hexane.Then with hexane with 25 microlitres/minute speed feed reactor, the flow velocity of hydrogen is approximately 25 ml/min simultaneously.

Originally, it is very slow that methane forms, but when test goes on, and subsequently just accelerated, and methane content reaches 4.5% at last.Then, the flow of feed gas through purifying of the front of 0.1 milliliter of tetrabutyl tin injection iron in 2 milliliters of hexanes will be dissolved in.The generation of methane be reduced to about 1% and afterwards 3 hours in continue to keep 1%.Data are summarized in the following table.

Table hour methane ethane propane hexane 19.2 0.0 0.5 0.3 98.620.7 1.06 2.08 1.74 93.421.2 2.62 4.55 3.92 85.321.5 3.43 4.23 3.83 84.621.9 4.45 4.50 4.32 82.022 add tetrabutyltin 22.6 1.16 3.81 4.12 86.223.0 1.16 3.96 4.24 85.922.3 1.0 4.56 3.77 87.524.3 0.97 3.60 3.76 87.625.3 1.0 4.47 3.57 88.0

As can be seen from the above results, tin is joined the accelerator that has just stoped generation methane in the steel fiber, and make it in product, to be reduced to an acceptable level.

Example 6

Utilize the steel fiber that scribbles tetrabutyl tin in advance to carry out the other test.Be exactly as in example 5 specifically, three such dosage that will be dissolved with 0.1 milliliter of tetrabutyl tin in 2 milliliters of hexanes are expelled in the 1/4 inch stainless steel tube that contains 0.15 gram steel fiber.Make solution in 900 hydrogen stream, pass through steel fiber.

Then hydrogen gas rate be approximately under the situation of 25 ml/min with 25 microlitres/minute the hydro carbons flow rate under 1175 temperature, feed hydrocarbon raw material.Analyze the methane of effluent and kept 24 hours being lower than under 1% the level.Then reactor is closed, and cut reactor tube open inspection.Extremely weak carburizing phenomenon only appears on steel fiber.

Do pre-treatment without tetrabutyl tin, do the contrast test and compare.Diel is carried out in test under the condition identical with the above.After 24 hours, detect less than hydrogen or raw material in the outlet of pipe, intake pressure rises to 300 pounds by original 50 pounds.When reactor is broken away inspection, find that coke is fully with the pipe plug plug.

Therefore, as can be seen, organo-tin compound can prevent the carburizing of steel fiber under the condition of reorganization.

Example 7

Be similar to another test of example 1 controlled trial, study car-burization condition and be coated with the influence of the Stainless Steel Wire of tin with vapor method in the gold-plated reactor tube being placed on.The difference unique with controlled trial just has been to use the higher like this hydrogen flow rate of 100 ml/min.

Controlled trial has been carried out 8 hours, excessive methane do not occur stopping up or forming.When pipe being cut open analysis, do not observe and stop up or a large amount of carbon.The striped that the carbon of a black only occurs at a steel wire.This may be because improper the causing of coating.

This test shows that tin can protect stainless steel not to be subjected to the influence of carburizing in a kind of mode of similar sulphur.Yet different with sulphur, it does not need continuously to be injected in the material.Sulphur continuously injecting material so that in this system, make the dividing potential drop of hydrogen sulfide remain on a level that is enough on steel, maintain a sulfide surface.As long as from raw material, remove desulfuration, from reactor assembly, be removed the appearance that the back just will cause the carburizing phenomenon at sulphur.This normally occurs within 10 hours after breaking off sulphur.

Above according to these through preferred embodiments when the present invention will be described, people will be appreciated that those skilled in the art will appreciate that in this area, can adopt many change types and improvement project.For example, the several portions of reactor assembly can be coated nickel, zirconium, SiO 2-ceramic, tungsten or chromium (chromium plating), may be very difficult although these technology are done or used, or price is too high.Perhaps, also can be using heat exchanger that the operation that hydro carbons is heated to temperature of reaction is minimized.Heat can provide by crossing hot hydrogen.Perhaps by using big caliber and higher pipe flow speed can reduce the exposure of heating surface to hydro carbons.Thus, many change type and improvement projects at above preferred embodiment are arranged in fact, these are conspicuous for these professional those skilled in the art, and they are being included in the scope of the present invention like that following claims limited.

Claims (37)

1. one kind is used for hydrocarbon material is carried out the method that catalytic reforming is produced aromatic hydrocarbons, it can be operated in long-time and can not cause the obstruction of reactor assembly, this method is used a kind of reforming catalyst to sulfur sensitive that is filled with one or more the 8th family metals, and this method comprises:

I) by the sulphur content in the hydrocarbon material is reduced to the sulphur that is lower than 50ppb, reaching has acceptable stability and activity to reforming catalyst, thereby a kind of low-sulfur hydrocarbon-bearing material is provided;

Ii) provide a kind of when the material that uses sulphur content to be lower than 50ppb is reformed, has the come off reactor assembly of performance of improved impervious carbon and metal-powder, said system comprises that at least one is used to heat the stove of above-mentioned material to the catalytic reforming temperature, described stove comprises with above-mentioned material and contacting, and have come off a plurality of boiler tubes of performance of impervious carbon suitable and metal-powder at least with 347 stainless steels, and

Above-mentioned low-sulfur hydrocarbon-bearing material is contacted by above-mentioned reactor assembly and with above-mentioned reforming catalyst to produce aromatic hydrocarbons, and wherein reforming reaction is carried out at 372-566 ℃ (700-1050 °F).

2. according to the method for claim 1, it is characterized in that:

(a) described boiler tube is by 347 stainless steels or have the impervious carbon suitable with 347 stainless steels and the come off steel of performance of metal-powder is made; Or

(b) described boiler tube comprises plating with a kind of, coats, and japanning or coating treat that the method on the boiler tube surface that contacts with material handled, with the performance that provides improved impervious carbon and metal-powder to come off, or

(c) described boiler tube comprises that randomly furnace lining is made of stupalith.

3. according to the method for claim 1 or 2, it is characterized in that described reforming catalyst is the macrovoid zeolite catalyst.

4. according to the method for claim 3, it is characterized in that described catalyzer is a platinum L-zeolite catalyst.

5. according to the method for claim 2, it is characterized in that described boiler tube is formed from steel, and on the steel surface for the treatment of to contact, applied a kind of electrolytic coating, coating layer, doped envelope or overlay with the material that heats.

6. according to the method for claim 2, the surface portion that it is characterized in that described boiler tube is to make by suitable steel by having at least with 347 stainless anti-carburizings.

7. according to the method for claim 6, it is characterized in that having applied electrolytic coating in the part of the described steel for the treatment of to contact, coating layer, doped envelope or overlay with the material that heats.

8. according to the method for reforming hydrocarbon material of being used to of claim 1, it is characterized in that described hydro carbons contacts with catalyzer under low water condition.

9. according to the method for reforming hydrocarbon material of being used to of claim 1, be included under the condition of low-sulfur and low water, reform in a reactor assembly, at least a portion of this reactor assembly has the anti-carburizing energy bigger than Aluminium Coated Steel.

10. according to the method for reforming hydrocarbon material of being used to of claim 1, it is characterized in that the reactor assembly that at least a portion contacts with material is a kind of not nickeliferous substantially alloy.

11. the method for reforming hydrocarbon material of being used to according to claim 1 is characterized in that the reactor wall of the reactor assembly that at least a portion contacts with material has suitable with 347 stainless steels at least anti-carburizing energy.

12. the method for reforming hydrocarbon material of being used to according to claim 1 is characterized in that the reactor assembly that at least a portion contacts with material is to be selected from by copper, tin, arsenic, antimony, brass, lead, bismuth, chromium, the material in the group of their intermetallic compound and their alloy composition.

13. the method that hydrocarbon material is reformed that is used for according to claim 12 is characterized in that the reactor assembly that at least a portion contacts with hydro carbons is Cu-Sn alloy or Cu-Sb alloy.

14. the method that hydrocarbon material is reformed that is used for according to claim 12 is characterized in that described material is a kind of tin that is selected from, the material of its intermetallic compound or its alloy.

15. the method that hydrocarbon material is reformed that is used for according to claim 12 is characterized in that described material still can effectively keep its anti-carburizing energy after oxidation.

16. the method for the reformation hydrocarbon material of a claim 1, being included in the low-sulfur condition makes material contact with reforming catalyst, and add the impervious carbon and the anti-coking reagent of at least a non-sulphur, so that reactor assembly has greater than 347 stainless anti-carburizing energy.

17. method of reforming hydrocarbon material of being used to according to claim 16, comprise and add a kind of being selected from by organo-tin compound, organo-antimony compound, bismuth organic compound, a kind of impervious carbon and anti-coking reagent in the group that organoarsenium compound and organo-lead compound are formed.

18. the method for reforming hydrocarbon material of being used to according to claim 17 is characterized in that adding a kind of impervious carbon and anti-coking reagent organotin of non-sulphur.

19. the method according to the reformation hydrocarbon material of claim 1 or 2 is characterized in that the described reactor assembly of at least a portion is with having tin, antimony, and the rich chromium steel of the metallic coating of bismuth or arsenic is made.

20. the method for reforming hydrocarbon material of being used to according to claim 19 is characterized in that the described reactor assembly of at least a portion is to make with the rich chromium steel of the metallic coating with tin.

21. the method according to the reformation hydrocarbon material of claim 1 or 2, the surface that it is characterized in that at least a portion steel in the described reactor assembly is coated with and applies thin chromium oxide coating earlier with aluminium or tin coating.

22. method according to the reformation hydrocarbon material of claim 1 or 2, it is characterized in that in described reactor assembly, having at least the surface of a part of steel to be coated with the coating that one deck is made of aluminium earlier, carry out aftertreatment technology then, described aftertreatment technology comprises that coating comprises the metallic coating of tin.

23. method according to the reformation hydrocarbon material of claim 1 or 2, it is characterized in that this reactor assembly has the hydrogen stream preheating of a part with the temperature that is heated to about 399-621 ℃ (750-1150) at least, then described reactor is preheated part and is exposed to the colder air-flow that temperature is approximately 204-427 ℃ (400 to 800), this air-flow comprises hydrogen and a kind of organo-metallic tin compound.

24. the method according to the reformation hydrocarbon material of claim 1 is characterized in that a part of metallic surface scribbles aluminium in this reactor assembly, aluminum oxide, and chromium or chromium oxide film, or by aluminized or chromed material manufacturing.

25. the method according to claim 1 or 2 is characterized in that described reactor assembly to small part is made of stupalith.

26. the method according to claim 1 is characterized in that, this reactor assembly has at least a part of metallic surface to scribble thin silicon-dioxide or silicon fiml.

27. method according to claim 1, it is characterized in that, when under the condition that is lower than 50ppb sulphur, reforming, the temperature of the part that is made of soft steel in the reactor assembly is no more than 510 ℃ (950 °F), and the temperature of the part that is made of stainless steel in the reactor assembly is no more than 552 ℃ (1025 °F).

28. method according to claim 1, it is characterized in that, a kind of decomposable, that have reactive behavior, stanniferous coating of coating at least a portion steel of reforming reactor system, described coating is reduced to a kind of tin with reactive behavior, when heating under reductive condition, its that part of reforming reactor system of described tin and coating forms tin iron.

29., it is characterized in that said coating comprises the tin compound that (i) can be decomposed by hydrogen, (ii) a kind of solvent systems, (iii) a kind of metallic tin in small, broken bits, and (iv) a kind of stannic oxide according to the method for claim 28.

30., it is characterized in that the described tin compound that can be decomposed by hydrogen is a stannous octoate according to the method for claim 29.

31., it is characterized in that the particle size of described tin in small, broken bits is approximately the 1-5 micron according to the method for claim 29 or 30.

32. according to the method for claim 29, it is characterized in that described solvent systems contains to be selected from Virahol hexane and pentane at least a.

33., it is characterized in that described solvent systems contains Virahol according to the method for claim 32.

34. according to the method for claim 29, it is characterized in that it does not contain reactionless active material, this material will stop that part that will apply coating in active tin and the reactor assembly to react.

35., it is characterized in that described coating comprises according to the method for claim 5 or 7:

(I) one or more sn-containing compounds, and

(ii) one or more iron cpds, and Fe/Sn weight ratio is no more than 1: 3.

36., it is characterized in that described iron cpd is Fe according to the method for claim 35 ₂O ₃

37. method according to claim 1, it is characterized in that, when being exposed in a kind of carbonization gas under 593-649 ℃ of (1100-1200) temperature, and when recently estimating with the weight percent of obtained carbon, its impervious carbon and the metal-powder performance that comes off is suitable with 347 stainless steels at least.

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