CN103059959A - Technological method for producing low sulfur gasoline - Google Patents

Abstract

The invention discloses a technological method for producing low sulfur gasoline. The method consists of: subjecting FCC (fluid catalytic cracking) gasoline to fractionation by a hydrogenation prefractionator to obtain gasoline light fraction and heavy fraction, conducting fixed bed oxidation deodorization on the light fraction, mixing the deodorized product with thermal catalytic diesel oil, subjecting the mixture to fractionation by a fractionating tower so as to obtain light fraction and diesel oil fraction; carrying out a hydrogenation pretreatment on the gasoline heavy fraction first to remove unstable diene, then performing selective hydrodesulfurization through high activity/low activity combined catalyst, and mixing the desulfurization product with the deodorized light fraction so as to obtain a clean gasoline product. Compared with the prior art, the method disclosed in the invention can produce the clean gasoline product with a sulfur content of less than 10 micrograms/g and an octane number loss of not more than 1.5 units. At the same time, normal operation of a hydrogenation device can be prevented from being influenced by a coke precursor generated by oxidation deodorization, so that the running cycle of the device can be prolonged. The method provided in the invention has the advantages of wide raw material adaptability and flexibility, mature technology, and high reliability.

Description

A kind of processing method of producing low-sulphur oil

Technical field

The present invention relates to a kind of inferior patrol and produce the method for low-sulphur oil, specifically, the present invention relates to a kind of device coking of avoiding, prolong operating period, and the processing method of producing low-sulphur oil.

Background technology

Reduce the quantity discharged that content of sulfur in gasoline can reduce objectionable impurities in the vehicle exhaust significantly, therefore, countries in the world clean gasoline new standard has proposed more and more stricter restriction to sulphur content.The sulphur content of Europe IV class automobile exhaust emission standard (EU2005 standard) regulation gasoline after 2005 ≯ 50 μ g/g, olefin(e) centent ≯ 18v% implements sulphur content less than 10 μ g/g " sweet gasoline (ULSG) " new standard after 2009.The sulphur content of U.S.'s U.S.EPA Tier 2-II standard code U.S.'s clean gasoline after 2006 ≯ 80 μ g/g, olefin(e) centent ≯ 14v%, the sulphur content of U.S.EPA Tier 2-III standard code U.S.'s clean gasoline after 2008 ≯ 30 μ g/g; China in 2005 national gasoline on July 1 is carried out European II emission standard (sulphur content ≯ 500 μ g/g), and European III emission standard (sulphur content ≯ 150 μ g/g) is carried out in the major area; On July 1st, 2007～2008, European III emission standard was carried out in the whole nation, and European IV emission standard (sulphur content ≯ 50 μ g/g) is carried out in the major area; On July 1st, 2010～2011, European IV emission standard was carried out in the whole nation.Before and after 2013, the big city clean gasolines such as Beijing, Shanghai will be carried out Europe V standard, require sulphur content ≯ 10 μ g/g.

At present, catalytic cracking (FCC) is the important sources of gasoline, be more than 80% such as the shared ratio of FCC gasoline in the Chinese refinery gasoline product, and the FCC sulfur content in gasoline is generally 200～1000 μ g/g, and mercaptans content is generally 20～100 μ g/g.Therefore, FCC gasoline sulfur and mercaptans content are all higher, and the sulphur content and the mercaptans content that reduce FCC gasoline are to satisfy the key of stricter clean gasoline specification.

Hydrogenating desulfurization (HDS) technique is the important means of effective elimination FCC gasoline sulfur and mercaptan, still, adopts traditional catalyzer and technique, and in the FCC gasoline hydrodesulfurizationmethod, the alkene significantly saturated meeting of hydrogenation causes larger loss of octane number.In order to reduce the loss of sweet gasoline octane value, develop many selective hydrodesulfurizations (HDS) raw catalyst and technique both at home and abroad.

US6,692,635 have introduced a kind of low-sulphur oil production technique.Be characterized at first selectively removing diolefine in selective hydrogenation device (the first reactor) of full cut catalytic gasoline raw material, olefines double bond isomerizing and mercaptan are converted into higher boiling sulfur compound.Then, the fractionation in a separation column of selective hydrogenation product is lighting end and last running.Last running is the MoO in the first reaction zone of hydrogenator (the second reactor) at first ₃-CoO/Al ₂O ₃Hydrogenation on the catalyzer is converted into saturated sulfide (such as tetramethylene sulfide or mercaptan) with unsaturated sulfide (such as thiophene and alkylated substituted thiazoline fen thereof), then, and the NiO/Al in second reaction zone ₂O ₃Hydrogenation on the catalyzer is converted into H with saturated sulfide (such as thiophene and alkylated substituted thiazoline fen thereof) ₂S.The desulfurization degree of this patented method is generally 80.0%～92.0%, and the product sulphur content is generally 96 μ g/g～240 μ g/g, 1.4～3.0 units of research octane number (RON) (RON) loss.Its shortcoming is not satisfy the Technology Need that oil refining enterprise is produced clean gasoline sulphur content ≯ 10 μ g/g.

EP1031622 discloses a kind of method of full cut FCC gasoline hydrodesulfurizationmethod.The first step is saturated with unsaturated sulfide hydrogenation in the FCC gasoline, is converted into mercaptan sulfur compounds, and second step is H with saturated sulphur compound hydrodesulfurizationconversion conversion again ₂S.Its advantage is the full cut FCC gasoline of processing, does not need to carry out fractionation, and weak point is that the remaining sulphur compound major part of the finished product is mercaptan sulfur compounds, causes in the product mercaptan sulfur defective.

CN 02133136.7 has introduced a kind of catalyst for selective hydrodesulfurizationof of gasoline and technique, is characterized in being lighting end and last running with the prefractionation of FCC gasoline first, and last running is at low metal/high metal content MoO ₃-CoO/Al ₂O ₃After the hydrogenating desulfurization, mix with lighting end again on the combination catalyst.This patented method shortcoming is owing to contain H in the last running HDS product ₂The more macromolecular mercaptan that S and the rearrangement reaction of alkene secondary generate on the one hand, has reduced the degree of depth of HDS, and on the other hand, the follow-up mercaptan removal that must carry out is processed.The desulfurization degree of this patented method is generally 80.0%～90.0%, the product sulphur content is generally 50 μ g/g～200 μ g/g, ≯ 2.0 units of research octane number (RON) (RON) loss do not satisfy the Technology Need that oil refining enterprise is produced clean gasoline sulphur content ≯ 10 μ g/g.

CN 02121594.4 has introduced a kind of method of producing low-sulphur oil.The method is that gasoline stocks is cut into lighting end and last running, lighting end is through the soda finishing mercaptan removal, last running contacts with Hydrobon catalyst together with hydrogen, carry out the selective hydrodesulfurization reaction, gasoline fraction behind the hydrogenation carries out hydrogenation or non-hydro-sweetening, and light, last running after the desulfurization are mixed to get gasoline products.The method can the production sulphur content be lower than 200 μ g/g, and the anti-knock index of gasoline ((RON+MON)/2) loss is not more than 2.0 units.Its shortcoming is to satisfy the Technology Need that oil refining enterprise is produced clean gasoline sulphur content ≯ 10 μ g/g.

CN 101307255A has introduced a kind of method of producing low sulfur gasoline by using by inferior gasoline fractions.The method is first full cut bad gasoline to be fixed an oxidation deodorizing, mercaptan sulfur is converted into disulphide, then fractionation is lighting end and last running, last running is carried out selective hydrodesulfurization through high reactivity/low activity combined hydrogenation desulfurization catalyst, and desulfurization product and lighting end are mixed to get the clean gasoline product.The method can production sulphur content ≯ 10 μ g/g gasoline products.But the fixed bed oxidation deodorizing can cause gasoline component to contact with oxygen, has accelerated green coke, is unfavorable for the long-term operation of device.

In the prior art, the subject matter of FCC gasoline production low sulfur clean gasoline product is that several respects contradiction can not take into account solution simultaneously, as sulfide under the contradiction between desulfurization depth and the loss of octane number, the hydrodesulfurizationconditions conditions remove and contradiction, deodorization and the desulfurization of mercaptan between generating between contradiction etc. so that existing Technology can not obtain low-sulfur, loss of octane number is few, mercaptan is qualified clean gasoline product simultaneously.In addition, the handiness of art methods is relatively poor, and is relatively poor to the adaptability of different material, is unfavorable for the long-term operation of device.

Summary of the invention

For the deficiencies in the prior art, the present invention proposes a kind of processing method of producing low-sulphur oil, adopts the method for staging treating, obtains sulphur content ≯ 10 μ g/g clean gasolines, and loss of octane number is few simultaneously, and device is long running period.

The processing method that the present invention produces low-sulphur oil comprises the following steps:

(1) stable gasoline that comes from catalytic cracking unit enters the hydrogenation preliminary fractionator, extracts lighting end out from cat head, tells last running at the bottom of the tower, and the cutting temperature of described lighting end and last running is 40 ℃～80 ℃;

(2) lighting end in the step (1) is fixed an oxidation deodorizing, mercaptan sulfur is converted into disulphide;

(3) gained oxidation deodorizing product in the step (2) and thermocatalysis diesel oil distillate are mixed, fractionate out gasoline lighting end and diesel oil distillate through separation column, diesel oil distillate is as the diesel hydrotreating unit charging, and doing of gasoline lighting end is 40 ℃～80 ℃;

(4) step (1) gained last running mixes with hydrogen, enters hydrogenation pretreatment reaction device, selective hydrogenation and removing diolefine and mercaptan;

(5) step (4) gained pre-treatment product carries out the selective hydrodesulfurization reaction by high reactivity/low activity combined hydrogenation desulfurization catalyst bed under the hydrodesulfurization reaction condition;

(6) hydrogenation products that step (5) is obtained with the lighting end of step (3) gained gasoline is mixed to get sulphur content less than the clean gasoline product of 10 μ g/g.

The cut point temperature of the described light fractions of FCC naphtha of step (1) and last running is 40～80 ℃, is preferably 50～70 ℃.

The described fixed bed oxidation deodorizing of step (2) can adopt the common method in this area to carry out, as take sulfonation titanium cyanines cobalt as catalyzer take air as the oxidation deodorizing process of oxygenant; Perhaps can adopt the alkali-free sweetening technology to carry out mercaptan removal, the sweet gasoline mercaptan sulfur after deodorization is processed generally can reach ≯ 10 μ g/g.

The described thermocatalysis diesel oil distillate of step (3) comes from the catalytic cracking diesel oil that the catalytic cracking unit distillation tower fractionates out, and doing of catalytic diesel oil cut is generally 330～380 ℃.The cut point temperature that the described sweet gasoline of step (3) and catalytic diesel oil cut are cut into lighting end and last running is 40～80 ℃, is preferably 50～70 ℃, can adopt conventional distillation mode to carry out fractionation.

The hydrogenation pretreatment catalyst that loads in the pretreatment reaction device described in the step (4) composed as follows: take the weight of catalyzer as benchmark, cupric oxide is 20.0wt%～50.0wt%, is preferably 30.0wt%～40.0wt%; Zinc oxide is 50.0wt%～80.0wt%, is preferably 60.0wt%～70.0wt%; Cupric oxide and zinc oxide weight ratio scope are 2: 1～1: 4, and optimum range is 1: 1～1: 2; The BET specific surface area is 30～60m ²/ g, optimum range are 35～45m ²/ g; Pore volume is 0.1～0.25cm ³/ g, optimum range are 0.15～0.20cm ³/ g; Average pore diameter is 10～25nm, and optimum range is 15～20nm.

The preparation method of described pretreatment catalyst is: the co-precipitation solution of soluble copper salt and zinc salt is mixed with a kind of organic acid soln or organic acid ammonium salt solution precipitator, co-precipitation goes out the mixture of a kind of insoluble mantoquita and zinc salt, obtain filter cake through aging, filtration, drying, roasting obtain cupric oxide and zinc oxide mixture again, be pressed at last the gasoline fraction mercaptan-eliminating catalyst, catalyzer can be sheet, column, strip, spherical or other suitable shape.

Wherein said soluble copper salt and zinc salt are one or more in chlorate, vitriol, acetate, the nitrate; The organic acid coprecipitator is one or more in oxalic acid, propanedioic acid, Succinic Acid, pentanedioic acid and the ammonium salt thereof.

The pretreated condition of heavy fractioning hydrogenation described in the step (4) is: reaction pressure is 0.5MPa～4.0MPa, and hydrogen to oil volume ratio is 50: 1～500: 1, and temperature of reaction is 130 ℃～220 ℃, and volume space velocity is 0.5～10h during liquid ^-1In this step, under the effect of pretreatment catalyst, the a small amount of mercaptan that contains in the last running and diolefine be respectively by hydrogenation and removing, thereby slowed down the chance of heavy fractioning hydrogenation desulphurization reactor generation coking, prolonged the running period of downstream heavy fractioning hydrogenation desulphurization reactor.

In the described high reactivity of step (5)/low activity combined hydrogenation desulfurization catalyst, the general content of reactive metal in the change catalyzer that passes through is to regulate the activity of catalyzer, active metallic content can differ 5.0wt%～18.0wt% in oxide compound in the catalyzer, preferably differs 8.0wt%～15.0wt%.Hydrogenation active metals generally is selected from one or more among W, Mo, Ni and the Co, can contain conventional auxiliary agent, such as among K, Ca, P, Si, F, B, Ti and the Zr one or more.Metal oxide content is 8.0wt%～20.0wt% in the described high activity hydrogenation and desulphurization catalyst, is preferably 10.0wt%～18.0wt%; Auxiliary agent content is 1.0wt%～6.0wt%, particularly 1.5wt%～5.0wt%; Metal oxide content is 1.0wt%～12.0wt%, particularly 3.0wt%～10.0wt% in the SA Hydrobon catalyst, and auxiliary agent content is 1.0wt%～6.0wt%, particularly 1.5wt%～5.0wt%.Reaction mass is successively by high activity hydrogenation and desulphurization catalyst and low activity Hydrobon catalyst.

The grating mode of described high reactivity/low activity combined hydrogenation desulfurization catalyst bed is: along the Flow of Goods and Materials direction, high activated catalyst is positioned at the upstream, and low activity catalyst is positioned at the downstream.Wherein the ratio of the admission space of high activated catalyst/low activity catalyst is 20/80～80/20.

Step (4) is described to add H in the hydrogen that hydrogen pretreatment and the described hydrogenating desulfurization of step (5) use ₂S content ≯ 300 μ L/L, preferred ≯ 50 μ L/L, generally by recycle hydrogen de H ₂S realizes.The control hydrodesulfurization process is used H in the hydrogen ₂The content of S can effectively be controlled the generation of mercaptan in the hydrogenation products.CO in the hydrogen ₂And/or CO content ≯ 50 μ g/g, preferred ≯ 10 μ g/g, the control hydrodesulfurization process is used CO in the hydrogen ₂And/or the content of CO, can effectively control the hydrogenating desulfurization rate of catalyzer.

Step (3) is introduced the thermocatalysis diesel oil distillate that catalytic cracking unit fractionates out, can dissolve a small amount of coking precursor that the alkali-free sweetening unit generates, thereby can slow down the coking of heavy naphtha selective hydrogenation unit, prolong the running period of hydrodesulfurization unit.Separation column is introduced the catalytic diesel oil hot feed simultaneously, has both reduced upstream device fractionation unit cooling load, provides again this device separation column required heat, has further reduced the operation energy consumption of separation column and gasoline selective hydrogenation unit.

Total sulfur content in the gasoline lighting end that step (3) oxidation deodorizing product fractionates out can reach and be not more than (≯) 10 μ g/g; Gasoline last running is after adding hydrogen pretreatment in the step (4), total mercaptan content of product ≯ 10 μ g/g, diene content ≯ 0.2gI/100g; Total sulfur content in step (5) the last running selective hydrodesulfurization product can reach ≯ 10 μ g/g; The total sulfur content of mix products can reach ≯ 10 μ g/g, and loss of octane number can be less than 1.5 units.

In the prior art, the subject matter of FCC gasoline production low-sulphur oil product is that the conversion of mercaptan in the light boiling range petroleum naphtha, hydrodesulfurization process loss of octane number are many, hydrodesulfurization process is followed mercaptan generation etc.Sulfur compound in the light boiling range petroleum naphtha mainly is mercaptan, and the sulfur compound in the heavier boiling range naphtha stream mainly is thiophene and other heterocycle sulfocompounds, can not remove mercaptan so separate by fractionation separately.If think the clean gasoline of production sulphur content ≯ 10 μ g/g, the mercaptan in the light boiling range petroleum naphtha must be removed or transforms the sulfide of attaching most importance to.The fixed bed oxidation deodorizing method can transform the sulfide of attaching most importance to the mercaptan in the light boiling range petroleum naphtha, do not lose simultaneously octane value, but the oxidation deodorizing process can cause gasoline component to contact with oxygen simultaneously generates the coking precursor, accelerates the downstream unit green coke, is unfavorable for the long-term operation of device.

The present invention fractionates out lighting end and last running through separation column first to catalytically cracked gasoline, lighting end is fixed an oxidation deodorizing, and mix with thermocatalysis diesel oil, lower boiling mercaptan changes into high boiling disulphide and is dissolved in the thermocatalysis diesel oil in the lighting end, a small amount of coking precursor that the simultaneous oxidation deodorization generates also is dissolved in the diesel oil distillate because boiling range is heavier.Diesel oil distillate as the diesel hydrotreating unit charging, is removed the coking precursor indirectly, slowed down the coking of heavy petrol selective hydrogenation unit, prolong operating period.Under the condition of deep desulfuration, the loss of octane number of the inventive method is also very low simultaneously.

The present invention selects a kind of special diolefine and mercaptan hydrogenation catalyst simultaneously, and this catalyzer has the pure and mild diolefine selectivity of higher hydrogenating desulfurization and activity.Use this catalyst towards heavy distillation gasoline to carry out pre-treatment, the diolefine that selectively removing is active and mercaptan are avoided diolefine condensation green coke under comparatively high temps, help equally the running period of extension fixture.

Description of drawings

Fig. 1 is the schematic flow sheet of the inventive method.

Embodiment

Gasoline stocks described in the inventive method can be fluid catalytic cracking (FCC) gasoline, catalytic cracking gasoline, coker gasoline, pressure gasoline etc. or its mixture.The preferred raw material of the present invention is FCC gasoline.Described inferior patrol hydrogenating materials can be full cut FCC gasoline, and its boiling range is generally 30 ℃～220 ℃, particularly 30 ℃～180 ℃.

Fixed bed oxidation deodorizing technique described in the inventive method can adopt arbitrary form of the prior art, as adopting alkali-free sweetening treatment process etc.Fixed bed oxidation deodorizing technique illustrates in many patent documentations, such as US4033806, and US4481106, US4746494, US5741415, US5849656, US5858212, U.S.Pat.5961819, CN1028765C, CN1031854A and CN1670134A etc.Therefore, any those of ordinary skill in the art can process according to existing method.

The cut point temperature of the FCC gasoline lighting end of telling from the hydrogenation preliminary fractionator of the present invention is 40～80 ℃, is preferably 50～70 ℃, and the yield of lighting end is generally the 20.0wt%～40.0wt% of gasoline stocks.The cut point temperature that obtains lighting end from the separation column fractionation behind the oxidation deodorizing is 40～80 ℃, is preferably 50～70 ℃, the total sulfur content of the lighting end that the oxidation deodorizing aftercut obtains ≯ 10 μ g/g.The total sulfur content of catalytically cracked gasoline last running selective hydrogenation product ≯ 10 μ g/g.

The H that takes off of the present invention ₂The S recycle hydrogen is preferably controlled H ₂S content ≯ 50 μ L/L, CO ₂And/or CO content preferred ≯ 10 μ L/L.Recycle hydrogen de H ₂The S method is generally conventional hydramine method.The flow process of hydramine method technique is generally: from the H that contains of reactive system ₂S hydrogen stream and hydramine adsorption solvent (such as ethylene glycol amine) counter current contact in adsorption tower is taken off H ₂The hydrogen of S is discharged from cat head, enters reactive system after recycle compressor boosts; The hydramine adsorption solvent of discharging from the adsorption tower bottom enters into solvent regeneration tower through after the manipulation of regeneration, returns and continues in the adsorption tower to use.The above-mentioned H that takes off ₂The S method is this area general knowledge, and those skilled in the art can process according to existing method.

Dialkene removal provided by the invention and mercaptan dual-function catalyst mantoquita and zinc salt coprecipitation process are as follows:

Become co-precipitation work salts solution take soluble copper salt and zinc salt as preparation of raw material, strength of solution is 0.1M～0.8M, preferably 0.3M～0.5M; With organic acid or organic acid ammonium salt preparation precipitant solution, strength of solution is 0.1M～0.8M, best 0.3M～0.5M, and its pH value is 3～7, is preferably 4～6; Then salts solution and the precipitant solution of will working respectively is heated to 15 ℃～70 ℃, is preferably 25 ℃～45 ℃.Under insulation and agitation condition, they are mixed, obtain the coprecipitate that suspends, the step such as wear out, filter, dry and obtain the coprecipitate filter cake through being incubated again.The precipitation agent consumption for 5%～20%(of surpassing cupric ion and zine ion in the work salts solution and being precipitated out required chemical reaction metering fully by weight percentage), be preferably 10%～15%(by weight percentage).The organic acid coprecipitator is one or more in oxalic acid, propanedioic acid, Succinic Acid, pentanedioic acid and the ammonium salt thereof.

Above-mentioned co-precipitation mode can be that the work salts solution is joined in the precipitant solution, or precipitant solution is joined in the work salts solution, also can be after they are heated respectively, joins in the settling bath simultaneously.

Above-mentioned coprecipitation process can be work salt to be joined respectively in two parallel header tanks with precipitant solution be heated to 15～70 ℃, is preferably 25～45 ℃, joins simultaneously in the low level settling bath under insulation and agitation condition.

The preparation process of dialkene removal provided by the invention and mercaptan dual-function catalyst is:

Gained coprecipitate filter cake is first dry, and then again roasting mixes resulting cupric oxide and zinc oxide mixture and pressing aid agent, and compression moulding namely makes catalyzer.The pressing aid agent is 2%～5% with the ratio of above-mentioned cupric oxide and zinc oxide mixture weight; The pressing aid agent can be graphite, stearic acid etc.; Drying temperature is 80 ℃～150 ℃, is preferably 100 ℃～120 ℃, 6～10 hours time, is preferably 8～10 hours; Maturing temperature is 300 ℃～500 ℃, is preferably 340 ℃～370 ℃, and the time is 2～6 hours, is preferably 4～5 hours.

Above-mentioned cupric oxide and zinc oxide mixture through step gained such as super-dry, roastings also can be mixed together evenly with pressing aid agent and tackiness agent, are pressed into catalyzer.Tackiness agent can be aluminum oxide, zeolite, silicon carbide, silicon-dioxide, silica-alumina, silicate, aluminate and borate etc.Certainly, the dialkene removal of the present invention's use and mercaptan dual-function catalyst can also adopt other proper method preparation.

Can contain other auxiliary agent in dialkene removal and the mercaptan dual-function catalyst, to improve catalyst performance, common auxiliary agent comprises chromic oxide, manganese oxide, magnesium oxide, barium oxide, aluminum oxide etc.

Dialkene removal and mercaptan dual-function catalyst need reduce before reaction, and reduction is adopted the method for capable territory routine and carried out.A kind of concrete catalyst reduction process and condition are: in the catalyst-assembly reactor, at pure hydrogen or contain under the hydrogen and nitrogen gas, be generally 0.5MPa～4.0MPa at reacting system pressure, the hydrogen volume air speed is generally 100～500h ^-1, reduction temperature is generally 160 ℃～300 ℃, and the constant temperature reduction is generally 1～10 hour.

High reactivity of the present invention/low activity combined hydrogenation desulfurization catalyst refers to adopt a kind of highly active Hydrobon catalyst and a kind of SA Hydrobon catalyst, its volume percent is 20/80～80/20, wherein highly active Hydrobon catalyst is positioned at the upstream of SA Hydrobon catalyst, namely along logistics direction activity decreased.

Metal oxide content is 8.0wt%～20.0wt%, particularly 10.0wt%～18.0wt% in the described high activity hydrogenation and desulphurization catalyst; Auxiliary agent content is 1.0wt%～6.0wt%, particularly 1.5wt%～5.0wt%; Metal oxide content is 1.0wt%～12.0wt%, particularly 3.0wt%～10.0wt% in the SA Hydrobon catalyst, and auxiliary agent content is 1.0wt%～6.0wt%, particularly 1.5wt%～5.0wt%.Described reactive metal is preferably one or more in cobalt, molybdenum, nickel and the tungsten.Auxiliary agent is preferably one or more in phosphorus, potassium and the fluorine.High reactivity can adopt identical reactive metal with the low activity Hydrobon catalyst, also can adopt different reactive metals.This catalyzer can adopt the pickling process preparation, can adopt step impregnation method, also can adopt co-impregnation.Steeping fluid can wait the adsorptive capacity dipping, also can be the excessive dipping of steeping fluid.

The present invention adopts the selective hydrogenation desulfurization process condition to be: the hydrogen dividing potential drop is generally 0.5MPa～5.0MPa, and temperature of reaction is generally 230 ℃～330 ℃, and volume space velocity is generally 2.0h during liquid ^-1～15.0h ^-1, hydrogen to oil volume ratio is generally 200: 1～and 1000: 1; The hydrogen dividing potential drop is preferably 0.8MPa～3.0MPa, and temperature of reaction is preferably 250 ℃～280 ℃, and volume space velocity is preferably 4.0h during liquid ^-1～10.0h ^-1, hydrogen to oil volume ratio is preferably 200: 1～and 700: 1.

The inventive method can be not more than the clean gasoline that production sulphur content ≯ 10 μ g/g, mercaptan sulfur content ≯ 10 μ g/g, maleic value in the situation of (≯) 1.0 units are not more than (≯) 0.2gI/100g in research octane number (RON) (RON) loss, satisfies the Technology Need of oil refining enterprise production sulphur content ≯ 10 μ g/g clean gasolines.

Further specify the inventive method process and effect below in conjunction with drawings and Examples.Logistics and each unit operation carry out in order along the direction of arrow.

Below in conjunction with Fig. 1 the inventive method is elaborated.

Catalytically cracked gasoline 1 fractionates out lighting end gasoline 2 and last running gasoline 3 in hydrogenation preliminary fractionator A.The oxidation deodorizing unit B that enters lighting end gasoline 2 realizes that mercaptan transforms, gasoline lighting end 4 after the conversion mixes with the hot diesel oil 5 of catalytic cracking that comes from catalytic cracking fractionating tower, fractionate out refining petroleum naphtha 6 and catalytic diesel oil 7 after interchanger C heat exchange in separation column D, catalytic diesel oil 7 removes diesel hydrotreating unit 10 after interchanger C heat exchange.The refining petroleum naphtha 6 that fractionates out in the disulphide separation column D goes product to be in harmonious proportion.The catalytically cracked gasoline last running 3 that fractionates out from hydrogenation preliminary fractionator A is introduced into pretreatment reaction device E and removes diolefine and mercaptan, enter hydrofining reactor F again and carry out the selective hydrodesulfurization reaction, reaction product 8 is in harmonious proportion with refining petroleum naphtha 6 and obtains clean gasoline product 9.

Further specify the solution of the present invention and effect below by embodiment, but therefore do not limit the present invention.

Example 1

This example adopts step impregnation method to prepare a kind of high reactivity MoO ₃(13.0wt%)-CoO (4.0wt%)-P ₂O ₅(1.5wt%)-K ₂O (2.0wt%)/Al ₂O ₃Catalyzer.

Take by weighing 1000g and intend thin water-aluminum hydroxide powder (Al ₂O ₃Contents on dry basis is 78wt%), adding accounts for Al ₂O ₃The sesbania powder extrusion aid of butt 5wt%, mass concentration are 10% aqueous nitric acid 200mL, mix and roll being mixed into plastic powder, prepare the cylindrical bars that diameter is 1.5mm with banded extruder, drying is 8 hours under 120 ℃, support of the catalyst is prepared in 500 ℃ of lower roastings 5 hours.

Press P on the catalyzer ₂O ₅Content is 1.5wt%, K ₂O content is 2.0wt%, gets quantitative phosphoric acid, saltpetre, adds deionized water, is made into the 120mL steeping fluid, and then, spray is on the said catalyst carrier of 160g.120 ℃ lower dry 10 hours, P is prepared in 500 ℃ of lower roastings 5 hours ₂O ₅(1.5wt%)-K ₂O-(2.0wt%)/Al ₂O ₃Catalyst intermediate.

Press MoO on the catalyzer ₃Content is that 13.0wt%, CoO content are 4.0wt%, gets quantitative molybdenum oxide, cobaltous dihydroxycarbonate, joins ammonia content and be 8% deionized water, is made into the 60mL steeping fluid, and then, spray is on the above-mentioned catalyst intermediate of 80g.120 ℃ lower dry 8 hours, high activated catalyst is prepared in 490 ℃ of lower roastings 6 hours, is called for short HAC.Nitrogen absorption under low temperature BET method is measured specific surface area of catalyst, pore volume character sees Table 1.

Example 2

This example adopts co-impregnation to prepare a kind of low activity MoO ₃(3.0wt%)-CoO (1.0wt%)-K ₂O (2.0wt%)/Al ₂O ₃Catalyzer.

Support of the catalyst is with reference to example 1 preparation.

Press MoO on the catalyzer ₃Content is that 3.0wt%, CoO content are 1.0wt% and K ₂O content is 2.0wt%, gets quantitative ammonium molybdate, Jing Ti/Bao Pian COBALT NITRATE CRYSTALS/FLAKES and saltpetre, adds the deionized water of ammonia content 16%, is made into the 110mL steeping fluid, and then, spray is on the said catalyst carrier of 165g.120 ℃ lower dry 8 hours, low activity catalyst is prepared in 500 ℃ of lower roastings 4 hours.This catalyzer is called for short LAC, and nitrogen absorption under low temperature BET method is measured specific surface area of catalyst, pore volume character sees Table 1.

Example 3

This example prepares a kind of hydrogenation pretreatment catalyst.

95.6 gram cupric nitrates and 235 gram zinc nitrates are mixed with 2000 milliliters of work salts solutions, 170 gram oxalic acid are mixed with 3000 milliliters of precipitant solution, and its pH value is adjusted to 3.0, then join respectively in two parallel high level tanks and be heated to 20 ℃, when treating low level settling bath heating in water bath to 20 ℃, start agitator, under strong mixing, two kinds of solution and flowing in the settling bath in 30 minutes, then under weak stirring, wore out 0.5 hour, then throw out is emitted, filter, spend the night and dry, obtain the coprecipitate filter cake, 110 ℃ lower dry 8 hours, then rose to 360 ℃ by room temperature in 6 hours, 360 ℃ of lower constant temperature calcinings 4 hours, make catalyst Precursors, then add an amount of graphite, mix rear compression molding, namely get hydrogenation pretreatment catalyst of the present invention, be numbered RM-1.RM-1 catalyzer physical property is listed in table 1.

The physical property of table 1 example 1～example 3 catalyzer

Project	Example 1	Example 2	Example 2
				The catalyzer numbering	HAC	LAC	RM-1
MoO 3, wt%	13.0	3.0	—
				CoO, wt%	4.0	1.0	—
K 2O, wt%	2.0	2.0	—
				P 2O 5, wt%	1.5	—	—
CuO，wt%	—	—	34.7
				ZnO，wt%	—	—	62.3
Specific surface area, m 2/g	220	240	41.1
				Pore volume, mL/g	0.40	0.45	0.20
Tap density, g/mL	0.79	0.73	0.70

Example 4

This example provides a kind of FCC gasoline desulfur effect inferior.

(1), a kind of FCC gasoline is fractionated out＜50 ℃ of petroleum naphthas and 50 ℃ of heavy petrol of ﹥ through the hydrogenation preliminary fractionator.

(2), ℃ catalytic gasoline lighting end oxidation deodorizing＜50:

＜50 ℃ of catalytic gasoline lighting end oxidation deodorizing catalyzer adopt commodity AFS-12 catalyzer (buying from University of Petroleum), at pressure 0.5MPa, 35 ℃ of temperature, volume space velocity 2.0h ^-1, gas-oil ratio (air/petroleum naphtha) condition under carries out deodorization at 1: 1.

(3), lighting end oxidation deodorizing product prefractionation:

＜50 ℃ of catalytic gasoline lighting end oxidation deodorizing products are mixed into separation column with thermocatalysis diesel oil to fractionate out＜50 ℃ of lighting ends (doing 52 ℃).＜50 ℃ of lighting ends go product to be in harmonious proportion,〉50 ℃ of double distilleds are divided into and have dissolved the macromole sulfide that transforms and the catalytic diesel oil of green coke precursor.Table 2 listed from the hydrogenation preliminary fractionator tell＜lighting end of 50 ℃ of FCC gasoline, behind 50 ℃ of FCC gasoline last running and the oxidation deodorizing from separation column tell＜character of the lighting end of 50 ℃ of FCC gasoline and thermocatalysis diesel oil.

The character of FCC gasoline, lighting end and last running in table 2 example 4

Project	FCC gasoline	＜50 ℃ of lighting ends	50 ℃ of last running	After the deodorization＜50 ℃ of lighting ends	Fractionation after heat diesel oil distillate
						The cutting ratio, wt%	100	25.8	74.2	-	-
Density, g/mL	0.7232	0.6456	0.7550	0.6456	0.94
						Sulphur content, μ g/g	460	37	520	10	9800
Mercaptan sulfur content, μ g/g	34.2	61.9	12	7	—
						Maleic value, gI/100g	2.78	1.20	3.32	1.20	—
Olefin(e) centent, v%	25.6	35.0	16.0	35.0	—
						Research octane number (RON)	92.4	94.8	90.5	94.8	—
Boiling range, ℃	32～188	30～52	48～190	30～52	178～360

(4),〉50 ℃ of catalytic gasoline heavy fractioning hydrogenations pre-treatment:

Pack among the reactor E 30 milliliters of RM-1 catalyzer, granularity is 20～40 orders.(air speed is 400h to logical hydrogen first ^-1), hydrogen pressure is 1.0MPa, rises to 260 ℃ by room temperature in 6 hours, then constant temperature reductase 12 hour.

Be cooled to 160 ℃ after the reduction, switch 50 ℃ of catalytic gasoline last running, the gasoline volume space velocity is 2.0h ^-1, the hydrogen dividing potential drop is 1.0MPa, hydrogen to oil volume ratio is 100: 1.After oil-feed is stablized 100 hours, sampling analysis.Table 3 has been listed the main character of raw material and product.

(5),〉50 ℃ of catalytic gasoline heavy fractioning hydrogenations desulfurization:

Evaluation test is that the device at fixed-bed reactor carries out, pack in the reactor 50mL high reactivity HAC and low activity LAC catalyzer, and the HAC/LAC volume ratio is 40/60.

Airtight qualified after, at first carry out catalyst vulcanization.Vulcanized oil is straight-run spirit, and vulcanizing agent is CS ₂, CS ₂Concentration is 1.0v%; Sulfide stress is 1.6MPa, and hydrogen to oil volume ratio is 300: 1, and the vulcanized oil volume space velocity is 2.0h ^-1, be 230 ℃ of lower constant temperature 8 hours in temperature, 300 ℃ of lower constant temperature 8 hours.

After sulfuration finishes, switch 50 ℃ of double distilleds are divided into stock oil, the hydrogen dividing potential drop is 1.6MPa, uses not sulfide hydrogen and CO/CO ₂Fresh hydrogen, volume space velocity is 3.0h ^-1, in 2 hours, be cooled to 260 ℃.Steady running sampling analysis in 100 hours.

(6),〉desulfurization of 50 ℃ of gasoline heavy fractioning hydrogenations mixes with＜50 ℃ of gasoline lighting ends

50 ℃ of heavy fractioning hydrogenation desulphurization reaction things go out with prefractionation＜50 ℃ of lighting ends mix according to the cutting ratio.Table 3 has been listed raw material FCC gasoline and the character of processing rear clean gasoline product.

The character of table 3 example 4 oil products

Project	FCC gasoline	50 ℃ of last running pre-treatment products	50 ℃ of heavy fractioning hydrogenation products	Mixing oil
					Density, g/mL	0.7232	0.7551	0.7551	0.7233
Sulphur content, μ g/g	460	355.0	4.0	5.0
					Mercaptan sulfur content, μ g/g	34.2	7.0	3.0	3.8
Maleic value, gI/100g	2.78	0.20	0.0	0.3
					Olefin(e) centent, v%	25.6	15.9	11.5	22.5
Research octane number (RON)	92.4	90.5	89.0	91.5
					C 5 +Yield, wt%	?	99.8	99.8	99.9
The steady running cycle, h	?	?	10000	?

As can be seen from Table 3: method of the present invention can be reduced to 5.0 μ g/g by 460 μ g/g with the sulphur content of FCC gasoline, mercaptan sulfur content is reduced to 3.8 μ g/g by 34.2 μ g/g, olefin(e) centent is reduced to 22.5v% by 25.6v%, and research octane number (RON) RON loses 0.9 unit, C ₅ ⁺Yield of gasoline 99.9wt%; Heavy petrol maleic value after adding hydrogen pretreatment is reduced to 0.3gI/100g by 3.32gI/100g, and mercaptan sulfur content is reduced to 7.0 μ g/g by 12 μ g/g, has removed easy green coke material, makes the device steady running, and the steady running cycle reaches 10000 hours.

Comparative Examples 1

This Comparative Examples provides a kind of FCC gasoline desulfur effect inferior.

(1), stock oil oxidation deodorizing

Stock oil oxidation deodorizing catalyzer adopts commodity AFS-12 catalyzer (buying from University of Petroleum), at pressure 0.5MPa, 35 ℃ of temperature, volume space velocity 2.0h ^-1, gas-oil ratio (air/FCC gasoline) condition under carries out deodorization at 1: 1.

(2), stock oil lighting end, last running cutting

Take 50 ℃ as the FCC gasoline of cut point temperature after with deodorization be separated into＜50 ℃ of lighting ends and 50 ℃ of last running, table 4 listed FCC gasoline,＜50 ℃ of lighting ends and the character of 50 ℃ of last running.

(3),〉50 ℃ of heavy fractioning hydrogenation desulfurization

Evaluation test is that the device at fixed-bed reactor carries out, pack in the reactor 50mL high reactivity HAC and a kind of low activity LAC catalyzer, and the former with the latter volume ratio is 40/60.

Airtight qualified after, at first carry out catalyst vulcanization.Vulcanized oil is straight-run spirit, and vulcanizing agent is CS ₂, CS ₂Concentration is 1.0v%; Sulfide stress is 1.6MPa, and the circulation hydrogen to oil volume ratio is 300: 1, and the vulcanized oil volume space velocity is 2.0h ^-1, be 230 ℃ of lower constant temperature 8 hours in temperature, 300 ℃ of lower constant temperature 8 hours.

After sulfuration finishes, switch 50 ℃ of double distilleds are divided into stock oil, the hydrogen dividing potential drop is 1.6MPa, uses not hydrogen sulfide containing fresh hydrogen, volume space velocity is 3.0h ^-1, in 2 hours, be cooled to 260 ℃.Steady running sampling analysis in 100 hours.

(4),〉50 ℃ of heavy fractioning hydrogenation desulfurization mix with＜50 ℃ of lighting ends

50 ℃ of heavy fractioning hydrogenation desulphurization reaction things go out with prefractionation＜50 ℃ of lighting ends mix according to the cutting ratio.Table 5 has been listed raw material FCC gasoline and the character of processing rear clean gasoline product.

The character of FCC gasoline, lighting end and last running in table 4 Comparative Examples 1

Project	FCC gasoline	Deodorization FCC gasoline	＜50 ℃ of lighting ends	50 ℃ of last running
					The cutting ratio, wt%	100	100	25.8	74.2
Density, g/mL	0.7232	0.7232	0.6456	0.7550
					Sulphur content, μ g/g	460	455	10	590
Mercaptans content, μ g/g	34.2	8.8	7	10
					Olefin(e) centent, v%	25.6	25.6	35.0	16.0
Research octane number (RON)	92.4	92.4	94.8	90.5
					Boiling range, ℃	32～188	32～188	30～52	48～190

The character of table 5 Comparative Examples 1 oil product

Project	FCC gasoline	50 ℃ of heavy fractioning hydrogenation products	Mixing oil
				Density, g/mL	0.7232	0.7551	0.7233
Sulphur content, μ g/g	460	18.0	16.0
				Mercaptan sulfur content, μ g/g	34.2	6.0	6.2
Olefin(e) centent, v%	25.6	11.0	21.5
				Research octane number (RON) (RON)	92.4	88.5	91.2
C 5 +Yield, wt%	—	99.8	99.9
				The steady running cycle, h	—	2000	—

As can be seen from Table 5: this Comparative Examples can be reduced to 16 μ g/g by 460 μ g/g with the sulphur content of FCC gasoline, mercaptan sulfur content is reduced to 6.2 μ g/g by 34.2 μ g/g, olefin(e) centent is reduced to 21.5v% by 25.6v%, and research octane number (RON) RON loses 1.2 units, C ₅ ⁺Yield of gasoline 99.9wt%.

Can find out that compare with Comparative Examples 1, the product sulphur content of example 4 of the present invention is lower, and loss of octane number is less.Simultaneously technical process of the present invention is because only carry out oxidation deodorizing to light fractions of FCC naphtha, and the green coke precursor that simultaneously oxidation deodorizing is produced is separated, and avoids at the hydrogenation unit green coke.Simultaneously the pre-treatment of catalytic cracking last running elder generation is removed diolefine and mercaptan, avoided at high temperature condensation green coke of diolefine, the steady running cycle that can extension fixture.

Example 5

This example provides another kind of FCC gasoline desulfur effect inferior:

(1), a kind of FCC gasoline is fractionated out＜70 ℃ of petroleum naphtha＞70 ℃ heavy petrol through the hydrogenation preliminary fractionator.

(2), ℃ catalytic gasoline lighting end oxidation deodorizing＜70

＜70 ℃ of catalytic gasoline lighting end oxidation deodorizing catalyzer adopt commodity AFS-12 catalyzer (buying from University of Petroleum), at pressure 0.5MPa, 40 ℃ of temperature, volume space velocity 2.0h ^-1, gas-oil ratio (air/petroleum naphtha) condition under carries out deodorization at 1: 1.

(3), petroleum naphtha oxidation deodorizing product prefractionation

＜70 ℃ of catalytic gasoline lighting end oxidation deodorizing products are mixed into separation column with thermocatalysis diesel oil to fractionate out＜70 ℃ of lighting ends (doing 71 ℃).＜70 ℃ of lighting ends go product to be in harmonious proportion,〉70 ℃ of double distilleds are divided into and have dissolved the macromole sulfide that transforms and the catalytic diesel oil of green coke precursor.Table 6 listed from the hydrogenation preliminary fractionator tell＜lighting end of 70 ℃ of FCC gasoline, behind 70 ℃ of FCC gasoline last running and the oxidation deodorizing from separation column tell＜character of the lighting end of 70 ℃ of FCC gasoline and thermocatalysis diesel oil.

(4),〉70 ℃ of catalytic gasoline heavy fractioning hydrogenations pre-treatment

Pack among the reactor E 30 milliliters of RM-1 catalyzer, granularity is 20～40 orders.Lead to first hydrogen (air speed 400h ^-1), hydrogen pressure is 1.0MPa, rises to 260 ℃ by room temperature in 6 hours, then constant temperature reductase 12 hour.

Be cooled to 150 ℃ after the reduction, feed switched is〉70 ℃ of catalytic gasoline last running, the gasoline volume space velocity is 2.0h ^-1, the hydrogen dividing potential drop is 1.0MPa, hydrogen to oil volume ratio is 200: 1.After oil-feed is stablized 100 hours, sampling analysis.Table 7 has been listed the main character of raw material and product.

(5),〉70 ℃ of catalytic gasoline heavy fractioning hydrogenations desulfurization

Evaluation test is that the device at fixed-bed reactor carries out, pack in the reactor 50mL high reactivity HAC and a kind of low activity LAC catalyzer, and the former with the latter volume ratio is 60/40.

Airtight qualified after, at first carry out catalyst vulcanization.Vulcanized oil is straight-run spirit, and vulcanizing agent is CS ₂, CS ₂Concentration is 1.0v%; Sulfide stress is 1.6MPa, and the circulation hydrogen to oil volume ratio is 300:1, and the vulcanized oil volume space velocity is 2.0h ^-1, 230 ℃ of lower constant temperature of temperature 8 hours, 300 ℃ of lower constant temperature 8 hours.

After sulfuration finishes, switch 70 ℃ of double distilleds are divided into stock oil, the hydrogen dividing potential drop is 1.6MPa, uses not sulfide hydrogen and CO/CO ₂Fresh hydrogen, volume space velocity is 3.0h ^-1, in 2 hours, be cooled to 280 ℃.Steady running sampling analysis in 100 hours.

(6),〉70 ℃ of heavy fractioning hydrogenation desulfurization mix with＜70 ℃ of lighting ends

70 ℃ of heavy fractioning hydrogenation desulphurization reaction things obtain with step (3)＜70 ℃ of lighting ends mix according to the cutting ratio.Table 7 has been listed raw material FCC gasoline and the character of processing rear clean gasoline product.

The character of FCC gasoline, lighting end and last running in table 6 example 5

Project	FCC gasoline	＜70 ℃ of lighting ends	70 ℃ of last running	After the deodorization＜70 ℃ of lighting ends	Fractionation after heat diesel oil distillate
						The cutting ratio, wt%	100	35.2	64.8	-	-
Density, g/mL	0.7110	0.6308	0.7510	0.6308	0.94
						Sulphur content, μ g/g	660	118	900	7	9800
Mercaptan sulfur content, μ g/g	32	44.6	16	3	—
						Maleic value, gI/100g	3.25	2.20	3.85	2.20	—
Olefin(e) centent, v%	31.0	40	22	40.0	—
						Research octane number (RON)	93.3	94.0	91.0	94.0	—
Boiling range, ℃	32～178	30～71	68～179	30～71	178～360

The character of table 7 example 5 oil products

Project	FCC gasoline	70 ℃ of last running pre-treatment products	70 ℃ of heavy fractioning hydrogenation products	Mixing oil
					Density, g/mL	0.7110	0.7511	0.7511	0.7110
Sulphur content, μ g/g	660	785	6.0	5.0
					Mercaptan sulfur content, μ g/g	32.0	8.0	4.0	3.8
Maleic value, gI/100g	3.25	0.3	0.0	0.3
					Olefin(e) centent, v%	31.0	21.0	15.3	27.0
Research octane number (RON)	93.3	90.8	88.8	92.0
					C 5 +Yield, wt%	?	99.9	99.8	99.9
The steady running cycle, h	?	?	9000	?

As can be seen from Table 7: method of the present invention can be reduced to 5 μ g/g by 660 μ g/g with the sulphur content of FCC gasoline, mercaptan sulfur content is reduced to 3.8 μ g/g by 32.0 μ g/g, olefin(e) centent is reduced to 27.0v% by 31.0v%, 1.3 units of research octane number (RON) loss, C ₅ ⁺Yield of gasoline 99.9wt%; Heavy petrol maleic value after adding hydrogen pretreatment is reduced to 0.3gI/100g by 3.85gI/100g, and mercaptan sulfur content is reduced to 8.0 μ g/g by 16 μ g/g, has removed easy green coke material, makes the device steady running, and the steady running cycle reaches 9000 hours.

Claims (13)

1. a processing method of producing low-sulphur oil comprises the following steps:

(1) stable gasoline that comes from catalytic cracking unit enters the hydrogenation preliminary fractionator, extracts lighting end out from cat head, tells last running at the bottom of the tower, and the cutting temperature of described lighting end and last running is 40 ℃～80 ℃;

(2) lighting end in the step (1) is fixed an oxidation deodorizing, mercaptan sulfur is converted into disulphide;

(3) gained oxidation deodorizing product in the step (2) and thermocatalysis diesel oil distillate are mixed, fractionate out gasoline lighting end and diesel oil distillate through separation column, doing of gasoline lighting end is 40 ℃～80 ℃;

(4) last running of gained gasoline mixes with hydrogen in the step (1), enters the pretreatment reaction device, selective hydrogenation and removing diolefine and mercaptan;

(5) step (4) gained pre-treatment product carries out the selective hydrodesulfurization reaction by high reactivity/low activity combined hydrogenation desulfurization catalyst bed under the hydrodesulfurization reaction condition;

(6) hydrogenation products that step (5) is obtained with step (3) gained lighting end is mixed to get the clean gasoline product.

2. in accordance with the method for claim 1, it is characterized in that the cut point temperature of the described light fractions of FCC naphtha of step (1) and last running is 50～70 ℃.

3. in accordance with the method for claim 1, it is characterized in that the described thermocatalysis diesel oil distillate of step (3) comes from the catalytic cracking diesel oil that the catalytic cracking unit distillation tower fractionates out, doing of catalytic diesel oil cut is 330～380 ℃.

4. in accordance with the method for claim 1, it is characterized in that the endpoint control of the described gasoline lighting end of step (3) is 40～80 ℃.

5. in accordance with the method for claim 1, it is characterized in that, the pretreatment catalyst that loads in the pretreatment reaction device described in the step (4) composed as follows: take the weight of catalyzer as benchmark, cupric oxide is 20.0wt%～50.0wt%, zinc oxide is 50.0wt%～80.0wt%, and cupric oxide and zinc oxide weight ratio scope are 2: 1～1: 4; The BET specific surface area is 30～60m ²/ g, pore volume are 0.1～0.25cm ³/ g, average pore diameter is 10～25nm.

6. in accordance with the method for claim 1, it is characterized in that, in the described high reactivity of step (5)/low activity combined hydrogenation desulfurization catalyst bed, active metallic content differs 5.0wt%～18.0wt% in oxide compound in high activated catalyst and the low activity catalyst.

7. according to claim 1 or 6 described methods, it is characterized in that active metallic content is counted 8.0wt%～20.0wt% with oxide compound in the described high activity hydrogenation and desulphurization catalyst, auxiliary agent content is 1.0wt%～6.0wt%; Metal content is counted 1.0wt%～12.0wt% with oxide compound in the described low activity Hydrobon catalyst, and auxiliary agent content is 1.0wt%～6.0wt%.

8. in accordance with the method for claim 1, it is characterized in that the grating mode of the described high reactivity of step (5)/low activity combined hydrogenation desulfurization catalyst bed is: along the Flow of Goods and Materials direction, high activated catalyst is positioned at the upstream, and low activity catalyst is positioned at the downstream.

9. in accordance with the method for claim 1, it is characterized in that wherein high activated catalyst is 20/80～80/20 with the ratio of the admission space of low activity catalyst.

10. in accordance with the method for claim 1, it is characterized in that the described selective hydrogenation desulfurization process condition of step (5) is: the hydrogen dividing potential drop is 0.5MPa～5.0MPa, temperature of reaction is 230 ℃～330 ℃, and volume space velocity is 2.0h during liquid ^-1～15.0h ^-1, hydrogen to oil volume ratio is 200: 1～1000: 1.

11. in accordance with the method for claim 1, it is characterized in that the described fixed bed oxidation deodorizing of step (2) adopts take sulfonation titanium cyanines cobalt as catalyzer take air as the oxidation deodorizing process of oxygenant, perhaps adopts the alkali-free sweetening technology to carry out mercaptan removal.

12. in accordance with the method for claim 5, it is characterized in that described pretreatment catalyst need reduce before reaction, the catalyst reduction condition is: at pure hydrogen or contain under the hydrogen and nitrogen gas, reaction pressure is 0.5MPa～4.0MPa, and the hydrogen volume air speed is 100～500h ^-1, reduction temperature is 160 ℃～300 ℃, constant temperature reduction 1～10 hour.

13. in accordance with the method for claim 5, it is characterized in that, the preparation method of described pretreatment catalyst is: the co-precipitation solution of soluble copper salt and zinc salt is mixed with a kind of organic acid coprecipitator, co-precipitation goes out the mixture of a kind of insoluble mantoquita and zinc salt, obtain filter cake through aging, filtration, drying, roasting obtain cupric oxide and zinc oxide mixture again, are pressed at last the gasoline fraction mercaptan-eliminating catalyst.

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