CN102851068B

CN102851068B - Gasoline desulfurization method

Info

Publication number: CN102851068B
Application number: CN201110184549.7A
Authority: CN
Inventors: 潘光成; 李涛; 吴明清; 陶志平; 张小云
Original assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Current assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Priority date: 2011-06-29
Filing date: 2011-06-29
Publication date: 2015-02-25
Anticipated expiration: 2031-06-29
Also published as: CN102851068A

Abstract

The inventive gasoline desulfurization method includes performing cutting distillation on gasoline to obtain heavy fraction with high boiling range and light fraction having low boiling range; under selective hydrogenation desulfurization condition, contacting the heavy fraction and hydrogen gas with hydrogenation desulfurization catalyst to perform selective hydrogenation desulfurization, to obtain desulfurized heavy fraction; contacting the light fraction with alkali solution, to obtain sulfide-absorbed alkali solution and desulfurized light fraction; contacting the sulfide-absorbed alkali solution and oxidant with oxidation catalyst, to obtain regenerated alkali solution; contacting the regenerated alkali solution with a part of the desulfurized heavy fraction to perform alkali solution desulfurization, and then performing phase separation to obtain disulfide-absorbed heavy fraction and desulfurized alkali solution; and returning at least part of the disulfide-absorbed heavy fraction to the heavy fraction after cutting distillation, to perform selective hydrogenation desulfurization. The inventive method can obtain higher desulfurization rate and lower octane number loss.

Description

A kind of method of gasoline desulfur

Technical field

The present invention relates to a kind of method of gasoline desulfur.

Background technology

As everyone knows, in vehicle exhaust, the discharge of hazardous and noxious substances drastically influence Air quality, and for this reason, countries in the world all define more and more stricter standard to the oil quality as motor spirit.On April 27th, 2005, State Environmental Protection Administration discloses Chinese Light-duty automobile III, No. IV emission standard.Wherein, light-duty vehicle No. III emission standard enforcement from 1 day July in 2007, No. IV emission standard enforcement from 1 day July in 2010.Country's No. III, No. IV emission standard respectively provides sulphur content in motor spirit and is not more than 150 μ g/g, 50 μ g/g.Estimate that in following country No. V emission standard regulation motor spirit, sulphur content is not more than 10 μ g/g.

As everyone knows, the sulphur in gasoline mainly comes from catalytic cracking (FCC) gasoline.Along with the raw material of FCC processing is to heaviness future development, increase causing the sulphur content of FCC gasoline further.Therefore, the sulphur content reducing FCC gasoline reduces the key point of finished product content of sulfur in gasoline.

Sulphur in gasoline comprises thio-alcohol, thioether class, disulfide class and thiophene-based (comprising thiophene and thiophene derivant) etc.As in the gasoline standard of fuel, its mercaptan sulfur content and total sulfur content have been prescribed most ceiling value.Mercaptan removal or desulfuration purification must be carried out to gasoline when mercaptan sulfur content exceeds standard or total sulfur content exceeds standard.

The method that gasoline desulfur usually adopts hydrogenation to combine with non-hydrotreatment, as, one method is light, heavy two portions by complete for gasoline cut fractionation, lighting end removes mercaptan by caustic extraction, last running carries out desulfurization process by hydrogenation, another kind method is that mercaptan is converted into higher boiling sulfur compound, is concentrated in last running by most of sulfide by fractionation.

In mercaptan removal, caustic extraction is a kind of traditional method of refining hydrocarbon material, be widely used in the process of the hydrocarbon materials such as liquefied petroleum gas (LPG), gasoline, diesel oil, petroleum naphtha, alkane, alkene, its method is contacted with alkali lye by hydrocarbon fluid, and the mercaptan in hydrocarbon stream removes from oil product by generating thiolate with alkaline reaction.And alkali lye containing thiolate if directly discharge is both uneconomical does not also meet environmental requirement.The method of usual use oxidation makes mercaptides become disulphide thus the alkali lye containing thiolate is regenerated.By injecting air and oxide catalyst in used alkali lye, the thiolate be dissolved in alkali lye is oxidized to disulphide, make alkali liquid regeneration thus, alkali lye after regeneration, by continuing to use after disulphide in settlement separate or varsol extracting regeneration alkali lye, thus substantially reduces the discharge of salkali waste.

Described caustic extraction generally comprises following continuous print basic step: (1) extracting, and (2) are oxidized, and (3) are separated.At extraction system, alkali lye contacts with hydrocarbon stream, absorbs out from hydrocarbon stream by mercaptan, and mercaptan and alkaline reaction generate thiolate; In oxidation system, the alkali lye containing thiolate from extraction system mixes mutually with injected air and oxide catalyst, and the thiolate in alkali lye is oxidized to disulphide; In phase-separation system, by sedimentation, regeneration alkali lye and disulphide are separated from the regeneration alkali lye of oxidation system and the mixture of disulphide to come, or sedimentation makes regeneration alkali lye separate with the solvent phase containing disulphide after being mixed with organic hydrocarbon flux by this mixture, usually the surplus air from oxidation system discharges at this, and returns extraction system with the regeneration alkali lye that disulphide is separated and continue to use.

In the prior art, it is pointed out that in the oxidation system of caustic extraction, in order to make the alkali liquid regeneration containing thiolate complete, usually will inject excessive air, and excess air flows into phase-separation system usually together with alkali lye, discharge in phase-separation system.Be made with two shortcomings like this: one is flow into solvent phase settlement separate that the air of phase-separation system easily forms aeration regeneration alkali lye and disulphide phase or contain disulphide in alkali lye, make to regenerate in alkali lye and be still entrained with disulphide or the solvent containing disulphide, return when extraction system recycles can disulphide back suction be mentioned in gasoline stocks at regeneration alkali lye, be difficult to reach the object of carrying out desulfurization with base extraction gasoline; Two is that regeneration alkali lye or the air contained by the fresh alkali lye of oxidation system injection are difficult to remove completely, regenerate alkali lye return extraction system recycle time, generate disulphide under the air of mercaptan at least partially in hydrocarbon stream in alkali lye and the effect with the oxide catalyst of alkali lye circulation still to stay in hydrocarbon stream and be not but absorbed in alkali lye, sweetening effectiveness like this is also not obvious.And when adopting extraction process process lighting end, the disulphide produced in alkali liquid regeneration process removes with reformed naphtha extracting usually, and extracting has the reformed naphtha of disulphide to need carrying device to arrive reformer process outward.

CN101275085A discloses a kind of combined method of gasoline desulfur, the method comprises and is cut into gently by gasoline, heavy two portions cut, last running is divided into again greatly, little two portions fluid, lighting end is contacted with alkali lye, mercaptan in lighting end is entered in alkali lye to generate thiolate by extracting, and make the mercaptides in alkali lye become disulphide, make alkali liquid regeneration, obtain the mixture regenerating alkali lye and disulphide, and above-mentioned small portion last running is absorbed as back suction extraction solvent the disulphide generated in lighting end caustic extraction process, and the small portion last running this being contained disulphide carries out selective hydrogenation process after mixing with above-mentioned most of last running.

The shortcoming of the method be used as back suction extraction solvent last running because containing surfactant and the metallocyclic compounds easily forming colloid as phenol, thiophenol, aniline etc., time settlement separate with regeneration alkali lye, emulsification is serious, more alkali lye is carried in last running after so making back suction carry, regeneration alkali lye after being carried by back suction carries more last running secretly, the efficiency making back suction carry disulphide on the one hand reduces, lighting end is declined by the mercaptan removal rate after caustic extraction and desulfurization degree, when last running after on the other hand back suction being carried flows into follow-up coalescer process, coalescence efficiency declines, the life cycle of coalescer shortens, and have influence on selective hydrogenation catalyst active reduction because of the more deposition of alkali.Especially, the selective hydrogenation catalyst adopted in described method is desulphurizing activated is not very high, is difficult to the product that acquisition sulphur content is not more than 50 μ g/g.

Summary of the invention

The object of the invention is to overcome above-mentioned defect of the prior art, a kind of method of new gasoline desulfur is provided, adopt method provided by the invention can carry out effective desulfurization to gasoline stocks, in addition, while effectively reducing sulfur content in gasoline, effectively can avoid the loss of octane value, obtain the gasoline of high-quality.

The invention provides a kind of method of gasoline desulfur, wherein, the method comprises the steps:

(1) gasoline is cut fractionation at the cut point temperature of 30-120 DEG C, obtain the relatively high last running of boiling range low lighting end relative to boiling range;

(2) under selective hydrodesulfurization condition, last running step (1) obtained and hydrogen contact with Hydrobon catalyst and carry out selective hydrodesulfurization, obtain the last running after desulfurization;

(3) lighting end step (1) obtained contacts with alkali lye carries out lighting end desulfurization, the condition of contact makes the sulfide in lighting end be entered in alkali lye to generate the salt of sulfide by extracting, the lighting end be absorbed after the alkali lye of sulfide and desulfurization of then carrying out being separated;

(4) under oxidative conditions, the alkali lye absorbing sulfide described in step (3) being obtained and oxygenant contact with oxide catalyst and carry out alkali liquid regeneration, the salt of the sulfide in alkali lye is oxidized to disulphide, obtains the alkali lye after regenerating, and tail gas is discharged;

(5) last running after desulfurization described in the part that the alkali lye after described regeneration step (4) obtained and step (2) obtain contacts carries out alkali lye desulfurization, the condition of contact makes the disulphide in alkali lye be entered in the last running after described desulfurization by extracting, and then carry out being separated the alkali lye be absorbed after the last running of disulphide and desulfurization;

(6) step (5) is obtained at least partially described in absorb disulphide last running turn back in step (2) and carry out described selective hydrodesulfurization or be recycled and reused in step (5) mixing with the last running after desulfurization described in the part obtained from step (2), after repeating alkali lye desulfurization, then return in step (2);

(7) lighting end after the described desulfurization that the last running after described desulfurization step (2) obtained and step (3) obtain is mixed to get product.

The method of gasoline desulfur provided by the invention is the combination process that hydrogenation combines with non-hydrotreatment, after the hydrogenation that the present invention adopts, last running easilier than non-hydrogenation last running to be separated (as the last running of back suction extraction solvent because containing surfactant and easily the metallocyclic compounds of formation colloid is as phenol with alkali lye, thiophenol, aniline etc., therefore, when the last running not carrying out hydrotreatment is settlement separate with regeneration alkali lye, emulsion is serious), be used for extracting with the last running after a part of described desulfurization simultaneously and remove disulphide in the alkali lye after regeneration and the remaining oxygen-containing gas of alkali lye entrained with after discharging tail gas, so can effectively avoid the oxidation of the alkali lye of the mercaptan in lighting end after extraction system is returned to the desulfurization in caustic extraction step (alkali lye after desulfurization preferably returns caustic extraction step) entrained with oxygen still to stay in lighting end with the form of disulphide but to fail to be absorbed in alkali lye with the form of the salt of sulfide, ensure that effectively carrying out of lighting end desulfurization, mercaptan in farthest raising lighting end is by the effect of caustic extraction, and adopt the last running after desulfurization to carry out the disulphide in extracting absorption alkali lye to the alkali lye after regeneration, and be blended in hydrogenation system with the last running from fractionating system and carry out selective hydrodesulfurization process, on the one hand need not as in alkali liquid regeneration process of the prior art with reformed naphtha extracting remove produce disulphide time need outside carrying device, as sent into reformer process, but be blended in hydrogenation system with the last running from fractionating system and carry out selective hydrodesulfurization process, on the other hand, because surfactant contained by the last running after desulfurization is substantially by hydrogenation and removing, be separated so easier after absorbing the disulphide in alkali lye with alkali lye, the alkali lye that may carry is less, also just can effectively avoid when being mixed into hydrogenation system process thus with the last running from fractionating system the selective hydrogenation catalyst in the present invention because of the larger deposition of alkali inactivation.

Other features and advantages of the present invention are described in detail in embodiment part subsequently.

Accompanying drawing explanation

Accompanying drawing is used to provide a further understanding of the present invention, and forms a part for specification sheets, is used from explanation the present invention, but is not construed as limiting the invention with embodiment one below.In the accompanying drawings:

Fig. 1 is the process flow sheet of the method for gasoline desulfur provided by the invention.

Embodiment

Below in conjunction with accompanying drawing, the specific embodiment of the present invention is described in detail.Should be understood that, embodiment described herein, only for instruction and explanation of the present invention, is not limited to the present invention.

The method of gasoline desulfur provided by the invention comprises the steps:

(1) by gasoline at 30-120 DEG C, cut fractionation under being preferably the cut point temperature of 40-80 DEG C, obtain the relatively high last running of boiling range low lighting end relative to boiling range;

According to the present invention, in step (1), by gasoline at 30-120 DEG C, the cutting technique that the method cutting into lighting end and last running under being preferably the cut point temperature of 40-80 DEG C can use for this area routine, such as, cut by separation column, wherein, most of mercaptan in gasoline and alkene have been concentrated in lighting end, and last running has concentrated other sulfide of the major part in gasoline and containing a small amount of mercaptan.

Wherein, described gasoline stocks can be the various gasoline stocks carrying out desulfurization that needs, such as, can be selected from catalytic cracking (FCC) gasoline, catalytic cracking gasoline, straight-run spirit, coker gasoline, pyrolysis gasoline and pressure gasoline one or more.

According to the present invention, the yield cutting lighting end and the last running obtained at described cut point temperature is respectively 10-60 % by weight and the 40-90 % by weight of gasoline stocks.

According to the present invention, in step (2), under selective hydrodesulfurization condition, last running step (1) obtained and hydrogen contact the condition of carrying out selective hydrodesulfurization with Hydrobon catalyst can be the selective hydrodesulfurization condition of this area routine, and can suitably adjust required desulfurization condition according to the degree of desulfurization.Such as, it can be 0.1-4MPa that the condition of described selective hydrodesulfurization comprises hydrogen dividing potential drop, is preferably 1-3.2MPa; Temperature of reaction can be 100-450 DEG C, is preferably 200-350 DEG C; Liquid hourly space velocity can be 1-10h ^-1, be preferably 2-6h ^-1, hydrogen to oil volume ratio can be 200-1000Nm ³/ m ³, be preferably 200-600Nm ³/ m ³.

According to the present invention, in step (2), described Hydrobon catalyst can may be used for removing the Hydrobon catalyst of other sulfide of major part in last running and a small amount of mercaptan for this area routine various.Such as, described Hydrobon catalyst is generally containing carrier and the hydrodesulfurization activity component of load on carrier, and with the gross weight of described catalyzer for benchmark, the content of described carrier is 60-99%, with oxide basis, the content of described hydrodesulfurization activity component is 1-40%.

Wherein, described hydrodesulfurization activity component generally can be selected from VI B race metal and VIII race's base metal one or more, under preferable case, described hydrodesulfurization activity component is molybdenum and/or tungsten and nickel and/or cobalt.

Described carrier can be the conventional various carriers used, the various heat-resisting porous material that this area is commonly used can be thought, particularly, described heat-resisting porous material can be heat-resisting inorganic oxide and/or silicate, preferably, described carrier is one or more in aluminum oxide, silicon oxide, titanium oxide, magnesium oxide, zirconium white, Thorotrast, beryllium oxide, clay and molecular sieve.More preferably, described carrier is one or more in aluminum oxide, silicon oxide and macropore or mesopore zeolite molecular sieve.

Under preferable case, with described total catalyst weight for benchmark, the content of described carrier is 69-97.8 % by weight, and with oxide basis, the content of described molybdenum and/or tungsten can be 2-25 % by weight, and the content of nickel and/or cobalt can be 0.2-6 % by weight.

In the present invention, the content of described molybdenum and/or tungsten (nickel and/or cobalt) refers to the total content of molybdenum and tungsten (or nickel and cobalt), namely, when described hydrodesulfurization activity component is simultaneously containing molybdenum and tungsten (or nickel and cobalt), this content represents the total content of molybdenum and tungsten (or nickel and cobalt); When described hydrodesulfurization activity component contain molybdenum and containing tungsten time (or containing nickel and containing cobalt time), this content represents the content of molybdenum (or nickel); When described hydrodesulfurization activity component contain tungsten and containing molybdenum time (or containing cobalt and containing nickel time), this content represents the content of tungsten (or cobalt).

Hydrobon catalyst described in the present invention can be prepared with reference to the various methods of prior art, such as can adopt conventional pickling process preparation, such as dry impregnation method (i.e. equi-volume impregnating), described dry impregnation method can be carried out as follows: will be selected from one or more the metal salt solution in VI B race metal and VIII race's base metal, be preferably molybdenum salt and/or tungsten salt and nickel salt and/or cobalt salt solution (as deionized water solution) and carrier contact, make in the final Hydrobon catalyst formed, with oxide basis, the content being selected from one or more the metal in VI B race metal and VIII race's base metal can be 1-40 % by weight, under preferable case, with oxide basis, make the content of molybdenum and/or tungsten can be 2-25 % by weight, the content of nickel and/or cobalt can be 0.2-6 % by weight.Then dry, roasting can obtain Hydrobon catalyst of the present invention.

Wherein, one or more metal salt solution in VI B race metal and VIII race's base metal will be selected from, be preferably molybdenum salt and/or tungsten salt and nickel salt and/or cobalt salt solution (as deionized water solution) to be undertaken by the following two kinds method with the method for carrier contact: one or more the metal-salt that (1) can will be selected from VI B race metal and VIII race's base metal, be preferably after molybdenum salt and/or tungsten salt and nickel salt and/or cobalt salt form a kind of mixed aqueous solution and again carrier be immersed; (2) one or more the metal that also can will be selected from VI B race metal and VIII race's base metal, be preferably molybdenum salt and/or tungsten salt and nickel salt and/or cobalt salt and be made into the aqueous solution separately, then carrier is contacted with selected salts solution (order of contact is selected arbitrarily) successively.

According to the present invention, one or more the metal-salt be selected from VI B race metal and VIII race's base metal is its water-soluble salt, wherein, described molybdenum salt can be various water-soluble molybdenum salt, as can be in various water-soluble molybdenum salt that Ammonium Heptamolybdate, ammonium tetramolybdate, ammonium dimolybdate etc. are conventional in one or more; Described tungsten salt can be various water-soluble tungsten salt, as being one or more in various water-soluble tungsten salt that ammonium tungstate, ammonium metawolframate, ethyl ammonium metawolframate, sulfo-ammonium tungstate, metatungstic acid nickel etc. are conventional; Described nickel salt is various water soluble nickel salt, as being one or more in various water soluble nickel salt that nickelous nitrate, nickelous chloride, single nickel salt, basic nickel carbonate etc. are conventional; Described cobalt salt is various water soluble cobaltous salts, as being one or more in various water soluble cobaltous salts that Jing Ti/Bao Pian COBALT NITRATE CRYSTALS/FLAKES, cobalt chloride, cobaltous dihydroxycarbonate etc. are conventional.

The present invention, can carry out with reference to the method for this area routine and condition without particular requirement the method for described drying, roasting and condition.Such as, dry temperature can be 80-200 DEG C, and the dry time can be 1-10 hour.The temperature of roasting can be 300-800 DEG C, is preferably 400-700 DEG C; The time of roasting can be 1-8 hour, is preferably 2-6 hour.

Under preferable case, last running and hydrogen contact the selective hydrodesulfurization carried out reaction with Hydrobon catalyst can comprise two step of reaction, first step of reaction is low temperature hydrogenation, for removing the diolefine in gasoline, prevent the polymerization coking that diolefine causes, the temperature of described first step of reaction is preferably 150-300 DEG C, and hydrogen dividing potential drop is preferably 1-3.2MPa, and liquid hourly space velocity is preferably 2-6h ^-1, hydrogen to oil volume ratio is preferably 200-600Nm ³/ m ³; Second step of reaction is selective hydrodesulfurization, and the temperature of the second step of reaction is preferably 250-350 DEG C, and hydrogen dividing potential drop is preferably 1-3.2MPa, and liquid hourly space velocity is preferably 2-6h ^-1, hydrogen to oil volume ratio is preferably 200-600Nm ³/ m ³.

In addition, can be the same or different in the kind of the Hydrobon catalyst of the first step of reaction and the second step of reaction, under preferable case, in order to reach better hydrogenating desulfurization effect further, adopt the Hydrobon catalyst of different activities in the first step of reaction and the second step of reaction, as the first step of reaction adopts low activity hydrogenation catalyst, hydrodesulfurization activity component is molybdenum and/or tungsten, subordinate phase adopts high-activity hydrogenation catalyst, and hydrodesulfurization activity component is nickel and/or cobalt.

According to the present invention, in step (3), lighting end step (1) obtained contacts with alkali lye carries out lighting end desulfurization, as long as the condition of contact ensures to make the sulfide in lighting end be entered in alkali lye to generate the salt of sulfide by extracting, and can suitably adjust required contact conditions according to extracting degree.Such as, the condition of described contact can comprise the temperature and pressure of contact, and wherein, the selectable range of the temperature and pressure of described contact is wider, and such as, the temperature of described contact can be subzero 10 DEG C to 100 DEG C, is preferably 0-50 DEG C; Pressure can be 0.1-2MPa, is preferably 0.1-1MPa.

In the present invention, as long as the concentration of described alkali lye and consumption guarantee fully to enter in alkali lye by the mercaptan extracting in lighting end, under preferable case, the volume ratio of described lighting end and alkali lye can be 1: 0.01-10, be preferably 1: 0.05-1, more preferably 1: 0.1-0.5.

Wherein, in step (3), described alkali lye can have extracting sulfide from gasoline for the various known of this area routine, the mainly alkaline reagents of the ability of mercaptan, such as, described alkali lye can be selected from the aqueous solution of ammoniacal liquor and alkali-metal oxyhydroxide one or more, wherein, described alkali-metal oxyhydroxide can be one or more in sodium hydroxide, potassium hydroxide and lithium hydroxide.Wherein, the concentration of ammoniacal liquor can be 1-30 % by weight, is preferably 5-25 % by weight; The concentration of the aqueous solution of alkali-metal oxyhydroxide can be 1-50 % by weight, is preferably 5-25 % by weight.In addition, in described alkali lye, auxiliary agent can also be contained, to promote the mercaptan in lighting end by alkali liquor absorption, to reach the object effectively improving lighting end desulfurization; Wherein, described auxiliary agent can be low-carbon alcohol (such as, methyl alcohol, ethanol and Virahol etc.), nitrogenous, phosphorus, oxygen, sulphur, arsenic, antimony compounds and various basic nitrogen compounds etc. routine use auxiliary agent in one or more, with the gross weight of alkali lye for benchmark, the content of described auxiliary agent is no more than 1000 μ g/g usually, preferably more than 500 μ g/g.

According to the present invention, in step (3), the phase disengagement method that the method that carrying out is separated has been absorbed the lighting end after the alkali lye of sulfide and desulfurization can be known to the skilled person, such as, settlement separate etc.

According to the present invention, under preferable case, the alkali lye in step (3) contains the alkali lye after the desulfurization obtained from step (5).Namely, for the ease of the circulation operate continuously of system, described lighting end desulfurization is carried out in turning back at least partially in step (3) of alkali lye after the described desulfurization that step (5) can be obtained, to be cycled to used in the sulfide in extracting lighting end.

According to the present invention, in step (4), under oxidative conditions, the alkali lye absorbing sulfide described in step (3) being obtained and oxygenant contact with oxide catalyst and carry out alkali liquid regeneration, make the contact conditions salt of the sulfide in alkali lye (mainly thiolate) being oxidized to disulphide can be the condition of this area routine, such as, the condition of described contact can comprise the temperature and pressure of contact, the temperature of described contact can be 0-100 DEG C, is preferably 0-80 DEG C; Pressure can be 0.1-2MPa, is preferably 0.1-1MPa.Under preferable case, described in step (4), pressure generally contacts lower than lighting end in step (3) pressure carrying out lighting end desulfurization with alkali lye.

According to the present invention, in step (4), described oxide catalyst can may be used for for the various of this area routine the oxide catalyst salt of the sulfide in the alkali lye of the salt (thiolate) containing sulfide being oxidized to disulphide.Under preferable case, the active ingredient of described oxide catalyst is metal phthalocyanine compound.

According to the present invention, in step (4), as long as the content of described oxide catalyst can play the effect that the salt of catalytic oxidant to alkali lye medium sulphide content is oxidized to disulphide.

Wherein, the use-pattern of described oxide catalyst can adopt any means well known in the art, such as, can be used by the form described metal phthalocyanine compound being dissolved in alkali lye or described metal phthalocyanine compound and alkali lye are mixed to get stable milk sap, also can pass through described metal phthalocyanine compound load on carrier, use with the form of loading type oxide catalyst.

Such as, when described metal phthalocyanine compound is by be dissolved in alkali lye or to use with the form that alkali lye is mixed to get stable milk sap, the content of described metal phthalocyanine compound in alkali lye can be 5-1000 μ g/g, preferred 10-400 μ g/g.

Such as, described metal phthalocyanine compound is when using with the form of loading type oxide catalyst, described loading type oxide catalyst contains carrier and the active ingredient of load on carrier, described carrier can be the porous material of the oxide catalyst of various this areas routine, and described active ingredient is metal phthalocyanine compound; With the gross weight of catalyzer for benchmark, the content of described carrier can be 90-99.9 % by weight, is preferably 95-99.9 % by weight; The content of described metal phthalocyanine compound can be 0.1-10 % by weight, is preferably 0.1-5 % by weight.

According to the present invention, in step (4), the oxygen-containing gas salt of sulfide being oxidized to disulphide can be various oxygen-containing gas, and the oxygen level of described oxygen-containing gas is at least 1 volume %, be preferably 10 more than volume %, be more preferably 10-50 volume %.Described oxygen-containing gas can be air (comprising oxygen-denuded air, oxygen-rich air) or oxygen.The amount of described oxygen-containing gas at least equals to make the salt of institute's sulfur compound in alkali lye to be oxidized to stoichiometric quantity needed for disulphide, is generally the 2-4 of required stoichiometric quantity doubly.After oxide treatment, the salt of the sulfide in alkali lye changes into disulphide, and therefore alkali lye regenerated.

In step (4), tail gas discharge after the alkali lye of salt containing sulfide step (3) obtained contact with oxide catalyst with oxygen-containing gas, can effectively avoid entrained air bubbles in alkali lye and affect the sweetening effectiveness of alkali lye and the sweetening effectiveness of lighting end after the desulfurization of following cycle use.

According to the present invention, continuous circulation for the ease of system operates, in described step (5), for the last running after desulfurization described in the part that double distilled after the desulfurization of the disulphide in the alkali lye after extracting regeneration is divided into step (2) to obtain, concrete consumption for last running after the desulfurization of the disulphide in the alkali lye after extracting regeneration can be determined according to the content of the actual amount of the alkali lye after regeneration and disulphide wherein, as long as the disulphide in the alkali lye after regenerating can be made to be entered in the last running after described desulfurization by extracting, under preferable case, after the amount of last running after the desulfurization obtained for a part of step (2) of disulphide in the alkali lye after extracting regeneration in described step (5) and whole desulfurization, the weight ratio of last running is 1: 10-500, be preferably 1: 50-200.

According to the present invention, the alkali lye after the described regeneration obtain step (4) makes the disulphide in the alkali lye after regenerating be entered in the last running after described partial desulfurization by extracting with step (2) as long as the condition that the last running after a part of desulfurization obtained contacts meets.Under preferable case, in step (5), the condition of described contact comprises temperature and pressure, and the adjustable extent of described Contact Temperature and pressure is wider, and temperature is higher, pressure is more conducive to more greatly the extracting of disulphide, but too high temperature and pressure is not obvious to the improvement of extraction rate was acquired, therefore, under preferable case, described temperature can be 0-100 DEG C, is preferably 0-80 DEG C; Pressure can be 0.1-2MPa, is preferably 0.1-1MPa.

According to the present invention, the mode that last running after a part of desulfurization that alkali lye after the described regeneration obtain step (4) and step (2) obtain contacts can adopt known various modes, as also stream contact mixing, counter current contact mixing etc., such as, the mode of described contact can adopt the static mixing mode without medium, or with orifice plate, granular filler is (as porcelain ball, nickel ring etc.), the way of contact that steel fiber or non-metallic fibers (thread or pencil) are medium, and with the way of contact that loading type oxide catalyst is medium, wherein, loading type oxide catalyst can for as described above by metal phthalocyanine compound be with the form of loading type oxide catalyst use loading type oxide catalyst.

In the present invention, the ratio of the last running after the desulfurization that the alkali lye after the regeneration that step (4) obtains and a part of step (2) obtain is not particularly limited, the consumption of the last running after the desulfurization that this part steps (2) obtains can be determined according to the amount of the disulphide in regeneration alkali lye, as long as can guarantee fully the disulphide extracting in the alkali lye after regeneration to be entered in described last running, under preferable case, after the desulfurization that alkali lye after the regeneration that step (4) obtains and this part steps (2) obtain, last running volume ratio is 1-500: 1, be more preferably 5-200: 1, more preferably 10-50: 1.

According to the present invention, in step (5), described in the method that the is separated method that can use for this area routine, as long as the alkali lye after the last running of the disulphide that can guarantee to be absorbed and desulfurization, such as, gravity settling separation.

In step (5), in the last running after making the disulphide in alkali lye be entered described desulfurization by extracting and when being separated, fluid liquid is divided into two-layer up and down, upper strata is the oil phase of the last running containing disulphide, and lower floor is the alkali lye phase after desulfurization.That is, in extracting and phase separation, disulphide separate out from alkali lye back suction propose the desulfurization on upper strata after last running in, and after separation of the phases, obtain the last running being substantially free of the alkali lye after the desulfurization of oxygen He absorbing disulphide.

When being separated, usually in phase-separation system, as carried out in settling separation system, usual use as fillers such as steel wire, sand, glass, coke as coalescing agent to promote disulphide coalescent in last running, as long as described contact, extracting can ensure abundant extracting with the residence time realizing being separated, can be preferably 0.5-2 hour, with fully carrying out of promoting further to be separated.In addition, when carrying out being separated (settlement separate), the oxygen-containing gas of the remnants carried in alkali lye can also be made further to be discharged.

According to the present invention, in order to the last running absorbing disulphide step (5) obtained recycles, and the productive rate of gasoline after ensureing desulfurization, therefore, the method also comprise step (5) is obtained at least partially described in absorb disulphide last running turn back in step (2) the last running mixing after carrying out described selective hydrodesulfurization or being recycled and reused for desulfurization described in the part that obtains from step (2) in step (5), after repeating alkali liquid regeneration, namely, again for the disulphide in extracting alkali lye, then return again in step (2).

Described step (5) obtain at least partially described in absorb the last running of disulphide amount be not particularly limited, can determine according to practical situation, such as, according to the content absorbing the disulphide in the last running of disulphide that the amount of disulphide or step (5) in the alkali lye after regeneration obtain, extracting ability when namely again carrying out extracting according to it and determining.

According to the present invention, under preferable case, in order to more be beneficial to the selective hydrodesulfurization process of last running, after step (5), before step (6), coalescent process is carried out in the last running absorbing disulphide that the method also comprises step (5) obtains, to remove wherein contained micro-alkali lye and other mechanical impurity.The coalescent treatment process that the method for described coalescent process can be known to the skilled person, such as, the described last running absorbing disulphide is contacted with coalescing agent (usually using if the fillers such as steel wire, sand, glass, coke are as coalescing agent), to promote that micro-alkali lye and other mechanical impurity are adsorbed on coalescing agent, and the residence time of described contact can be 0.1-2 hour.

According to the present invention, under preferable case, the method also comprises the last running part that step (5) obtains being absorbed disulphide and contacts with the tail gas that step (4) produces, to absorb the sulfur-bearing lighter hydrocarbons in tail gas, and this is absorbed disulphide, the last running of sulfur-bearing lighter hydrocarbons turns back in step (2) and carries out described selective hydrodesulfurization.The tail gas obtained can be passed through through light ends unit, for reclaiming in alkali lye with the micro-lighter hydrocarbons (such as, adopting heavy-hydrocarbon oil as the withdrawing can etc. of recovery catalyst) that air flows out.

Under preferable case, in order to by describedly absorbing disulphide, the last running of sulfur-bearing lighter hydrocarbons recycles, therefore, this is absorbed disulphide, the last running of sulfur-bearing lighter hydrocarbons turns back in step (2) and carry out described selective hydrodesulfurization.

According to the present invention, after employing method of the present invention carries out desulfurization process to gasoline, mercaptan sulfur content after the desulfurization obtained in last running is lower, usually between 1-50 μ g/g, under preferable case, according to needs of production, the product of 10 μ g/g is not more than in order to obtain mercaptan sulfur content further, before lighting end after the described desulfurization that last running after the method also comprises described desulfurization step (2) obtained and step (3) obtain is mixed to get product, the mixture of the lighting end after the described desulfurization that the last running after the described desulfurization obtain step (2) and step (3) obtain carries out deodorization process, or the lighting end after the described desulfurization obtained with step (3) again after deodorization process is carried out in the last running after the described desulfurization obtain step (2) is mixed to get product, the mercaptan sulfur content of the product obtained is made to be not more than 10 μ g/g.Wherein, the object of described deodorization adopts the mode of catalyzed oxidation to remove last running in hydrogenation process, have little time that carry out hydrogenation and newly-generated mercaptan, guarantees that in treated gasoline product, mercaptan sulfur content is not more than 10 μ g/g further.

According to the present invention, after employing method of the present invention carries out desulfurization process to gasoline, the gasoline products that total sulfur content reduces can be obtained equally, such as, the sulphur content of the gasoline products obtained can meet country's No. III emission standard and specify in motor spirit that sulphur content is not more than 150 μ g/g and meets country's No. IV emission standard and specify that in motor spirit, sulphur content is not more than the requirement of 50 μ g/g, under preferable case, the sulphur content of the gasoline products obtained meets estimates that following country No. V emission standard specifies that in motor spirit, sulphur content is not more than the requirement of 10 μ g/g.

According to the present invention, when productive target sulphur content is not more than the gasoline products of 10 μ g/g, to require that the weight of the lighting end total sulfur after desulfurization is at least not more than 10 μ g/g, and require that the weight of the last running total sulfur after desulfurization is at least also not more than 10 μ g/g, for this reason light by flexible, the cut point temperature of last running, the lighting end weight that sulfur-bearing (comprising mercaptan sulfur) is measured after desulfurization is made to be not more than 10 μ g/g, and make the last running weight that sulfur-bearing (comprising mercaptan sulfur) is measured after selective hydrogenation process also be not more than 10 μ g/g, lighting end after desulfurization and the last running after desulfurization are after step (7) mixes, obtain the product that sulphur and mercaptan sulfur content are not more than 10 μ g/g, the regulation of 10 μ g/g is not more than according to existing gasoline products mercaptan sulfur index, therefore the low-sulphur oil product that sulphur content is not more than 10 μ g/g directly need not be become after the last running after selective hydrogenation process mixes with the lighting end after mercaptan removal again through catalyzed oxidation deodorizing and refining.

In addition, lighting end after the described desulfurization that last running after the described desulfurization that step (2) obtains and step (3) obtain is mixed to get product, refers to that the two sulphur content weight is added the mogas production being directly mixed to get when being not more than 10 μ g/g and meeting expection state No. V emission standard sulphur content and specify.If, the two sulphur content weight is added and is greater than 10 μ g/g (such as producing the gasoline products meeting state III or state No. IV emission standard), and the two mercaptan sulfur content weight is added when being not more than 10 μ g/g, can without deodorization process, directly be mixed to get product, otherwise through deodorization process, need ensure that product mercaptan sulfur content is not more than 10 μ g/g.

The method that the method for described deodorization can adopt those skilled in the art to know altogether is carried out, and such as, the mode of liquid-liquid catalyzed oxidation can be adopted to carry out, the mode of fixed bed catalytic oxidation also can be adopted to carry out.

According to the mode of liquid-liquid catalyzed oxidation, oxide catalyst is the metal phthalocyanine compound being dissolved in alkali lye or being formed in alkali lye stable milk sap, the content of described metal phthalocyanine compound in alkali lye can be 5-1000 μ g/g, is preferably 10-500 μ g/g.Oxygenant is oxygen-containing gas, described oxygen-containing gas as foregoing teachings of the present invention define, preferably purify air, have little time that carry out hydrogenation and newly-generated mercaptan oxidation after the amount of air at least equals to make hydrogenation in last running and become stoichiometric quantity needed for disulphide, be preferably mercaptan oxidation is become the stoichiometric quantity needed for disulphide 2-4 doubly; Described oxygenant also can be selected or coordinate to select has the inorganic of oxidisability or organic oxygen-containing compound, as hydrogen peroxide etc.

According to the mode of fixed bed catalytic oxidation, then fixed bed deodorization catalyst is the metal phthalocyanine compound of load on porous material, under preferable case, adopts the mode of fixed bed catalytic oxidation to carry out.Described fixed bed deodorizing system is oxygenant (oxygenant is preferably oxygen-containing gas), and preferably under the existence of alkaline reagents, the mixture of the lighting end that last running and step (3) obtain after the desulfurization that step (2) is obtained, or after the desulfurization that step (2) obtains, last running and catalytic amount is that the metal phthalocyanine compound of carrier contacts with porous material, carries out deodorization reaction.

Wherein, the pressure of described fixed bed deodorizing system can be 0.1-2MPa, is preferably 0.2-0.8MPa.The temperature of fixed bed deodorizing system can be subzero 10 DEG C to 100 DEG C, and be preferably 0-80 DEG C, the liquid hourly space velocity after selective hydrogenation process can be 0.1-10h ^-1, be preferably 0.5-5h ^-1.

In described fixed bed deodorization catalyst, described carrier can be the porous material of the oxide catalyst of various this areas routine, and described active ingredient is metal phthalocyanine compound; With the gross weight of catalyzer for benchmark, the content of described carrier can be 90-99.9 % by weight, is preferably 95-99.9 % by weight; The content of described metal phthalocyanine compound can be 0.1-10 % by weight, is preferably 0.1-5 % by weight.

Described alkaline reagents can be selected from the alkaline reagents that any routine well known in the art uses, such as, the aqueous solution of inorganic alkali lye and/or alkaline organic compound, desirable inorganic alkali lye is generally the aqueous solution and/or the ammoniacal liquor of the oxyhydroxide of basic metal and/or alkaline-earth metal, such as, the oxyhydroxide of described alkali and alkaline earth metal ions can be selected from one or more in sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium hydroxide and hydrated barta.Alkaline organic compound in the aqueous solution of described alkaline organic compound can be one or more in organic amine compound, alkaloid compound and quaternary ammonium base, is preferably quaternary ammonium base.The amount of the aqueous solution neutral and alkali organic compound of described alkaline organic compound can be 0.1-1000 μ g/g, is preferably 0.5-100 μ g/g.

According to the present invention, when carrying out deodorization, no matter be liquid-liquid catalyzed oxidation mode or fixed bed catalytic oxidation mode, preferably catalyst aid (i.e. activator) exist under carry out, described catalyst aid can be polar compound and/or compounds, described polar compound can be selected from the basic nitrogen compound of low-carbon alcohol, alkyl amine basic nitrogen compound and the hydroxyalkyl amines such as water, methyl alcohol, ethanol, Virahol one or more.Described compounds can be quaternary ammonium compounds, compounds, compounds, antimony compounds, oxygen compounds and sulfonium one or more in compounds are N, P, As, Sb, O and S etc. as cationic atom respectively, are preferably quaternary ammonium salt and/or quaternary ammonium hydroxide.Be benchmark with the weight of pending oil product (such as, the last running of step (7) and the mixture of lighting end, or last running), the amount of described catalyst aid can be 0.1-1000 μ g/g, is preferably 0.5-500 μ g/g.

Described alkaline reagents and described catalyst aid can mix with pending gasoline after uses, also can pre-soaked or adsorb use together with metal phthalocyanine on a catalyst support.When described alkaline reagents is pre-soaked or adsorb on a catalyst support, its effective weight (quality of the solute in alkaline reagents) can account for the 0.1-40 % by weight of total catalyst weight, is preferably 0.1-20 % by weight.

In the present invention, described metal phthalocyanine compound, comprise the oxidation step of step (4) and step (7) or the metal phthalocyanine in the metal phthalocyanine compound used in deodorising step all can be selected from magnesium phthalocyanine, titanium phthalocyanines, hafnium phthalocyanine, vanadyl phthalocyanine, tantalum phthalocyanine, molybdenum phthalocyanine, manganese phthalocyanine, iron-phthalocyanine, cobalt phthalocyanine, platinum phthalocyanine, palladium phthalocyanine, copper phthalocyanine, silver-colored phthalocyanine, ZnPc and tin phthalocyanine one or more, be preferably cobalt phthalocyanine and/or vanadyl phthalocyanine.Described metal phthalocyanine compound can be selected from the sulfonate of metal phthalocyanine, carboxylate salt, quaternary ammonium salt and its compounds etc.

In the present invention, the metal phthalocyanine that deodorizing system uses is preferably negative ions to shaped metal phthalocyanine, is made up of with the metal phthalocyanine with negative ion group the metal phthalocyanine with positive ion group.The described metal phthalocyanine with positive ion group is selected from sulfonate, the carboxylate salt of metal phthalocyanine, the sulfonate of preferred cobalt phthalocyanine, comprises one in the tetrasulfonate (four sulfonated phthalocyanine cobalts) of the monosulfonate (single sulfonated phthalocyanine cobalt) of cobalt phthalocyanine, the disulfonate (two sulfonated phthalocyanine cobalt) of cobalt phthalocyanine, the trisulfonate (three sulfonated phthalocyanine cobalts) of cobalt phthalocyanine, cobalt phthalocyanine or wherein any mixture.The described metal phthalocyanine with negative ion group be selected from metal phthalocyanine quaternary ammonium salt, compounds, the quaternary ammonium salt of preferred cobalt phthalocyanine, its general formula is CoPc [N (R ₁r ₂r ₃) A] _a, wherein Pc is the symbol of general expression phthalocyanine basic structure, R ₁, R ₂, R ₃for the identical or different alkyl with 1-3 carbon atom, A is halide anion, and most preferred is I ^-, a is quaternized degree, and its value is 1-4.

The carrier of the fixed bed catalyst used in the deodorising step of the described oxidation step as step (2) and step (7) can be selected from the porous material containing aluminium, silicon, alkaline-earth metal, transition metal, rare earth metal and carbonaceous, as aluminum oxide, silicon oxide, silico-aluminate, calcium oxide, magnesium oxide, titanium oxide, natural and artificial clay, natural and permutite, carbonaceous material etc. from mineral material (as coal and oil etc.), vegetable material (as wood chip, shell fruit stone etc.) and synthetic resins etc., be preferably activated carbon.The specific surface of porous carrier can be generally 10-1500m ²/ g, is preferably 100-1200m ²/ g.

According to a preferred embodiment of the present invention, as shown in Figure 1:

Described Fig. 1 only represents preferred schema, and do not provide the details such as operating device of relevant vessel, well heater, water cooler, pump, compressor, mixing tank, valve, technological process, namely only indicating concerning people familiar with the art understand the present invention is basic or non-obvious equipment situation.

Feed gasoline enters fractionating system 2 through pipeline 1, gasoline lighting end is flowed out through pipeline 4, gasoline last running flows out laggard selectable hydrodesulfurizationsystem system 24 from pipeline 3, under the effect of low activity hydrogenation catalyst, carry out the first selective hydrogenation through the first hydroconversion reaction zone, and under high-activity hydrogenation catalyst effect, carry out the second selective hydrogenation through the second hydroconversion reaction zone.

Gasoline lighting end from fractionating system 2 enters extraction system 5 through pipeline 4.The alkali lye (from alkali lye (being drawn by pipeline 16) after the desulfurization of settling separation system 15) of fresh alkali lye or containing metal phthalocyanine catalyst enters extraction system 5 through pipeline 8, lighting end and alkali lye counter current contact in extraction system 5, sulfide (mercaptan) in lighting end is entered in alkali lye by extracting, generate the salt (thiolate) of sulfide, the lighting end after desulfurization leaves extraction system 5 by pipeline 7.

The alkali lye absorbing sulfide flows into oxidation and anti-extraction system 11 through pipeline 7, and and through pipeline 9 enter oxidation mix with the oxygenant (oxygen-containing gas) of anti-extraction system 11, carry out alkali liquid regeneration, the salt of the sulfide in alkali lye is oxidized to disulphide, obtain the alkali lye after regenerating.Usually, during as needs, fresh alkali lye and catalyzer can input through pipeline 8 or 10, and unnecessary oxygenant (being preferably oxygen-containing gas) discharges from oxidation and anti-extraction system 11 top through pipeline 12.

Mixture from the alkali lye after the regeneration of oxidation system 11 and remaining oxygen agent (oxygen-containing gas) mixes with from last running after a part of hydrogenating desulfurization of selective hydrodesulfurization system 24 (drawing through pipeline 26) settling separation system 15 flowing into phase-separation system through pipeline 13, the disulphide in the alkali lye after regenerating is made to be entered in the last running after described desulfurization by extracting, then be separated, the alkali lye after the last running of the disulphide that has been absorbed and desulfurization; And from settling separation system 15 top through pipeline 14 oxygen-containing gas that release is remaining further.

After settlement separate, alkali lye after desulfurization flows out from pipeline 16 and returns extraction system 5 through pipeline 8 and recycles, and the double distilled phase-splitting that absorb disulphide mutually unmixed with the alkali lye after desulfurization is flowed out through pipeline 17 substantially, can continue to mix by the alkali lye in pipeline 18 inflow line 27 after the regeneration from oxidation system 11, flow into settling separation system 15 settlement separate, carry continuously the disulphide in alkali lye for back suction, also can flow directly into through pipeline 19 and coalescently remove system 20.

The described last running oil phase absorbing disulphide flows out through pipeline 22 and coalescently removes system 20 (to remove the micro-alkali lye that may carry and to be discharged through pipeline 21 by impurity), and mix with the last running from fractionating system 2 from pipeline 3, then flow into hydrogenation system 24 and carry out selective hydrodesulfurization together with the hydrogen from pipeline 23.

Described last running and hydrogen carry out selective hydrodesulfurization reaction at low activity hydrogenation catalyst with contacting under the effect of high-activity hydrogenation catalyst, remove after hydrogen sulfide flow out hydrogenation system 24 through air lift.

Describedly be divided into two portions from last running after the hydrogenation after air lift of hydrogenation system 24 through pipeline 25, wherein after sub-fraction hydrogenation, last running is flowed out through pipeline 26-1, and mixed through pipeline 13 with the regeneration alkali lye from oxidation system 11 by pipeline 27, the disulphide in the alkali lye after regeneration is carried for back suction, and last running mixes with the lighting end that the extracting from pipeline 6 removes sulfide (mercaptan) mutually through pipeline 26-2 after remaining most of hydrogenation, and and the oxygen-containing gas from pipeline 28 and the activator from pipeline 29 (if possible, also activator can not be added) enter fixed bed deodorizing system 31 through pipeline 30 and carry out deodorization after mixing, to remove last running sulfide newly-generated in hydrogenation process (as mercaptan), final refining rear product is through pipeline 32 or flow out after sedimentation.

Below the preferred embodiment of the present invention is described in detail by reference to the accompanying drawings; but; the present invention is not limited to the detail in above-mentioned embodiment; within the scope of technical conceive of the present invention; can carry out multiple simple variant to technical scheme of the present invention, these simple variant all belong to protection scope of the present invention.

It should be noted that in addition, each concrete technical characteristic described in above-mentioned embodiment, in reconcilable situation, can be combined by any suitable mode, in order to avoid unnecessary repetition, the present invention illustrates no longer separately to various possible array mode.

In addition, also can carry out arbitrary combination between various different embodiment of the present invention, as long as it is without prejudice to thought of the present invention, it should be considered as content disclosed in this invention equally.

To be further described in detail the present invention by specific embodiment below.

The two kinds of catalyst for selectively hydrodesulfurizing used in following embodiment are provided by catalyzer branch office of Sinopec Group Chang Ling catalyst plant, and trade names are respectively RSDS-01 (low activity hydrogenation catalyst) and RSDS-02 (high-activity hydrogenation catalyst).

In following embodiment, the measuring method of described sulphur content is microcoulomb method known in those skilled in the art.

Embodiment 1

The present embodiment is for illustration of the sulfur method of gasoline provided by the invention.

In the present embodiment, the raw material catalytic cracking gasoline A process in the flow process his-and-hers watches 1 shown in accompanying drawing 1 is adopted.

(1) the cutting cut point of gasoline A is 75 DEG C, obtains the relatively high last running of boiling range low lighting end relative to boiling range, and after cutting, the yield of lighting end B and last running C is respectively 38 % by weight, 62 % by weight.

(2) in selective hydrogenation system, selective hydrogenation process is carried out in last running, the condition of the first selective hydrogenation comprises: reactive hydrogen dividing potential drop is 1.6MPa, temperature of reaction 240 DEG C, liquid hourly space velocity 3.0h ^-1, hydrogen to oil volume ratio 300Nm ³/ m ³.The condition of the second selective hydrogenation comprises: reactive hydrogen dividing potential drop is 1.6MPa, temperature of reaction 290 DEG C, liquid hourly space velocity 3.0h ^-1, hydrogen to oil volume ratio 300Nm ³/ m ³.Last running after hydrogenation is divided into two portions, and after sub-fraction desulfurization, after last running D and most desulfurization, the part by weight of last running E is 1: 75.

(3) in extraction system, the volume ratio of alkali lye and lighting end B is 0.5: 1, and temperature is 20 DEG C, and pressure is 0.5MPa.

(4) in oxidation system, in alkali lye, the content of sulfonated phthalocyanine cobalt (having Fine Chemical Works greatly purchased from Guangzhou) is 100 μ g/g, be 1: 4.5 as the injection rate of the oxygen-containing gas of oxygenant and alkali lye volume ratio, the pressure of oxidation system is 0.34MPa, and temperature is 50 DEG C.Wherein, described alkali lye to be mass percent concentration be 15% aqueous sodium hydroxide solution; Described oxygen-containing gas is air (oxygen volume content is 21%).

(5) in anti-extraction system, be 1: 25 for last running D after the sub-fraction desulfurization of the disulphide in the alkali lye after absorption and regeneration and the volume ratio of regeneration alkali lye, the pressure of anti-extraction system is 0.34MPa, and temperature is 50 DEG C.

The temperature of the settling separation system in phase-separation system and coarse separation system (filled media is polypropylene fibre material) is natural temperature 25 DEG C, pressure is natural pressure 0.1MPa, the alkali lye after the small portion hydrogenation of the disulphide that has been absorbed after being separated after last running D and desulfurization; And last running D mixes laggard selectable hydrogenation system and carries out hydrotreatment after this being absorbed the small portion hydrogenation of disulphide with last running C.

(6) after most of desulfurization, last running E mixes with the lighting end B from extraction system, then flows into fixed bed deodorizing system and carries out mercaptan removal process.Wherein, described fixed bed mercaptan removal system used catalyst is the sulfonated phthalocyanine cobalt (having Fine Chemical Works greatly purchased from Guangzhou) being carried on 1 on gac % by weight, and temperature of reaction is 40 DEG C, and pressure is 0.3MPa, and liquid hourly space velocity is 2.0h ^-1.

The essential property of raw material A is as shown in table 1, and raw material A is after above-mentioned process, and result respectively as shown in Table 1 and Table 2.

Comparative example 1

This comparative example is for illustration of the sulfur method of the gasoline of prior art.

Adopt the stock oil A identical with embodiment 1 and carry out gasoline desulfur according to the combination sulfur removal technology identical with embodiment 1, identical processing parameter, unlike, last running D after being used for back suction in embodiment 1 and proposing the sub-fraction desulfurization of disulphide in the alkali lye after regeneration is replaced with by the last running obtained after fractionation of feed gasoline being cut of step (1), in addition, in the selective hydrodesulfurization system of step (2), single RSDS-01 catalyzer is only adopted.And, describedly carry the identical with the consumption of last running D after sub-fraction desulfurization used in embodiment 1 by consumption feed gasoline being cut the last running obtained after fractionation of step (1) of disulphide in the alkali lye after regeneration for back suction, and mix with all the other the most of last running from fractionating system through coalescent process after disulphide in the alkali lye after back suction proposes regeneration, flow into hydrogenation system and carry out hydrogenating desulfurization process.Raw material A is after above-mentioned process, and result respectively as shown in Table 1 and Table 2.

Table 1

Result as can be seen from upper table 1, after method process provided by the invention, the desulfurization degree of raw material A is up to 95.3%, and product sulphur content is 40 μ g/g, meets the requirement that country's No. IV emission standard gasoline products sulphur content is not more than 50 μ g/g, olefin saturated rate only has 21.4%, RON loss only has 1.5 units, and the desulfurization degree of comparative example 1 is only 93.8%, and product sulphur content is 55 μ g/g, olefin saturated rate is that 30.0%, RON loss reaches 2.7 units.It can thus be appreciated that compared with comparative example 1, the method for the embodiment of the present invention 1 has better sweetening effectiveness and lower loss of octane number.

Table 2

Table 2 gives the determination data of sodium mercaptides content in the regeneration alkali lye after desulfurization, and adopts 90-120 DEG C of sherwood oil (without sulphur) to mix with alkali lye after desulfurization (after the desulfurization of embodiment 1, alkali lye refers to and flows out by alkali lye after the desulfurization of last running extracting disulphide after hydrogenation from Fig. 1 pipeline 18) equal-volume and sulphur content (sulphur content after desulfurization in alkali lye equals the sulphur content in measured sherwood oil) after desulfurization measured by after being separated in alkali lye.Sodium mercaptides content after desulfurization in alkali lye is more, when reuse, more unfavorable to lighting end extraction desulfurization, moreover, sulphur content after desulfurization in alkali lye is larger, after explanation desulfurization, in alkali lye, remaining sodium mercaptides content may be more on the one hand, and the last running on the other hand after explanation desulfurization entrained by alkali lye may be more, means that the separating effect of alkali lye and last running in phase-separation system is poor.

As can be seen from the data in upper table 1 and upper table 2, after small portion desulfurization, last running D by the complete extracting of disulphide in the alkali lye after regeneration, can adopt the better effects if of the non-desulfurization last running of small portion than comparative example 1.

Compared with remaining sulphur content in alkali lye after the desulfurization obtained after the disulphide last running extracting obtained after feed gasoline fractionation being removed in the alkali lye after regeneration adopted with comparative example 1, the sulphur content that alkali lye after the desulfurization obtained after disulphide in alkali lye after adopting the last running extracting after desulfurization to remove regeneration in the embodiment of the present invention 1 is remaining is much smaller, and the sodium mercaptides be essentially in alkali lye is transformed, illustrate that the last running after desulfurization is separated more complete with the alkali lye after desulfurization in phase-separation system, on the contrary, but a small amount of last running has been mixed in alkali lye in comparative example 1 after desulfurization, show as the increase of the content of sulphur remaining in the alkali lye after desulfurization, namely last running is relative poor at the separating effect of phase-separation system with the alkali lye after desulfurization, this part last running of so carrying micro-alkali lye secretly may cause disadvantageous effect to follow-up hydrogenation system.

Embodiment 2

In the present embodiment, the raw material catalytic cracking gasoline F process in the flow process his-and-hers watches 3 shown in accompanying drawing 1 is adopted.

(1) the cutting cut point of gasoline F is 60 DEG C, obtains the relatively high last running of boiling range low lighting end relative to boiling range, and after cutting, the yield of lighting end G and last running H is respectively 35 % by weight, 65 % by weight.

(2) in selective hydrogenation system, the temperature of reaction of the first selective hydrogenation is 290 DEG C, and the temperature of reaction of the second selective hydrogenation is 310 DEG C, and reaction hydrogen to oil volume ratio is 350Nm ³/ m ³, other conditions are all identical with the step (2) of embodiment 1.Last running after hydrogenation is divided into two portions, and after small portion hydrogenation, after last running M and most of hydrogenation, the part by weight of last running N is about 1: 150.

(3) in extraction system, the volume ratio of alkali lye and lighting end G is 0.1: 1, and temperature is 35 DEG C, and pressure is 0.2MPa.

(4) in oxidation system, in alkali lye, the content of sulfonated phthalocyanine cobalt (having Fine Chemical Works greatly purchased from Guangzhou) is 80 μ g/g, and the injection rate of oxygen-containing gas and alkali lye volume ratio are 1: 4.5, and the pressure of oxidation system is 0.6MPa, and temperature is 70 DEG C.Wherein, described alkali lye to be mass percent concentration be 15% aqueous sodium hydroxide solution; Described oxygen-containing gas is air (oxygen volume content is 21%).

(5) in anti-extraction system, be 1: 10 for last running M after the sub-fraction desulfurization of the disulphide in the alkali lye after absorption and regeneration and the volume ratio of regeneration alkali lye.The pressure of anti-extraction system is 0.6MPa, and temperature is 70 DEG C.

The temperature of the settling separation system in phase-separation system and coarse separation system (filled media is polypropylene fibre material) is natural temperature 25 DEG C, pressure is natural pressure 0.1MPa, the alkali lye after the small portion hydrogenation of the disulphide that has been absorbed after being separated after last running M and desulfurization; And last running M mixes laggard selectable hydrogenation system and carries out hydrotreatment after this being absorbed the small portion hydrogenation of disulphide with last running H.

In addition, deodorizing system (because of last running remix after the lighting end after mercaptan removal and hydrogenation, its sulphur content is not more than 10 μ g/g, and mercaptan sulfur content is also not more than 10 μ g/g) is closed.The essential property of raw material F and raw material F are after above-mentioned process, and result is as shown in table 3.

Table 3

Result as can be seen from table 3, after method process of the present invention, the desulfurization degree of raw material F all reaches more than 98.2%, product sulphur content is only 7 μ g/g, meet sulphur content in following country No. V emission standard gasoline products and be not more than the regulation of 10 μ g/g, and olefin saturated rate only has 9.8%, RON loss to only have 0.4 unit, it can thus be appreciated that the method for the embodiment of the present invention 2 has better sweetening effectiveness and lower loss of octane number.

Claims

1. a method for gasoline desulfur, is characterized in that, the method comprises the steps:

(2) under selective hydrodesulfurization condition, after the fractionation obtain step (1), last running and hydrogen contact with Hydrobon catalyst and carry out selective hydrodesulfurization, obtain the last running after desulfurization;

(3) after fractionation step (1) obtained, lighting end contacts with alkali lye and carries out lighting end desulfurization, the condition of contact makes the sulfide in lighting end be entered in alkali lye to generate the salt of sulfide by extracting, the lighting end be absorbed after the alkali lye of sulfide and desulfurization of then carrying out being separated;

(7) lighting end after the described desulfurization that the last running after described desulfurization step (2) obtained and step (3) obtain is mixed to get product;

Last running and hydrogen contact the selective hydrodesulfurization carried out reaction with Hydrobon catalyst comprises two step of reaction, and the temperature of the first step of reaction is 150-300 DEG C, and hydrogen dividing potential drop is 1-3.2MPa, and liquid hourly space velocity is 2-6h ^-1, hydrogen to oil volume ratio is 200-600Nm ³/ m ³, the hydrodesulfurization activity component of Hydrobon catalyst is molybdenum and/or tungsten; The temperature of the second step of reaction is 250-350 DEG C, and hydrogen dividing potential drop is 1-3.2MPa, and liquid hourly space velocity is 2-6h ^-1, hydrogen to oil volume ratio is 200-600Nm ³/ m ³, the hydrodesulfurization activity component of Hydrobon catalyst is nickel and/or cobalt.

2. method according to claim 1, wherein, in step (1), the cutting cut point of gasoline is 40-80 DEG C.

3. method according to claim 1, wherein, in step (1), the yield of lighting end and last running is respectively 10-60 % by weight and the 40-90 % by weight of gasoline.

4. method according to claim 1, wherein, in step (3), the temperature that the condition of contact comprises contact is subzero 10 DEG C to 100 DEG C, and pressure is 0.1-2MPa, and the volume ratio of described lighting end and alkali lye is 1:0.01-10.

5. method according to claim 1, wherein, the alkali lye in step (3) contains the alkali lye after the desulfurization obtained from step (5).

6. method according to claim 1, wherein, in step (4), the activeconstituents of described oxide catalyst is metal phthalocyanine compound.

7. method according to claim 1, wherein, in step (4), described oxygenant is oxygen-containing gas, and the amount of described oxygen-containing gas at least equals to make mercaptan salt in alkali lye be oxidized to the stoichiometric quantity needed for disulphide; The oxygen level of described oxygen-containing gas is at least 1 volume %.

8. method according to claim 1, wherein, in step (4), it is 0-100 DEG C that the alkali lye of the salt containing sulfide that described step (3) obtains comprises temperature with the condition that oxygenant contacts with oxide catalyst, and pressure is 0.1-2MPa.

9. method according to claim 1, wherein, in step (5), after whole desulfurization that the last running after desulfurization described in the part that described step (2) obtains and step (2) obtain, the weight ratio of last running is 1:10-500.

10. method according to claim 9, wherein, in step (5), after whole desulfurization that the last running after desulfurization described in the part that described step (2) obtains and step (2) obtain, the weight ratio of last running is 1:50-200.

11. methods according to claim 9, wherein, in step (5), it is 0-100 DEG C that the condition of contact comprises temperature, and pressure is 0.1-2MPa; The volume ratio of the last running after desulfurization described in the part that the alkali lye after step (4) obtains regeneration and step (2) obtain is 1-500:1.

12. methods according to claim 11, wherein, the volume ratio of the last running after desulfurization described in the part that the alkali lye after step (4) obtains regeneration and step (2) obtain is 5-200:1.

13. methods according to claim 1, wherein, the method also comprises the last running absorbing disulphide described in the part that step (5) obtained and contacts with the tail gas that step (4) produces, absorb the sulfur-bearing lighter hydrocarbons in tail gas, and this is absorbed disulphide, the last running of sulfur-bearing lighter hydrocarbons turns back in step (2) and carries out described selective hydrodesulfurization.

14. methods according to claim 1, wherein, in step (7), before lighting end after the described desulfurization that last running after the method also comprises described desulfurization step (2) obtained and step (3) obtain is mixed to get product, the mixture of the lighting end after the described desulfurization that the last running after the described desulfurization obtain step (2) and step (3) obtain carries out deodorization process; Or the lighting end after the described desulfurization obtained with step (3) again after deodorization process is carried out in the last running after the described desulfurization obtain step (2) is mixed to get product, the mercaptan sulfur content of the product obtained is made to be not more than 10 μ g/g.

15. methods according to claim 1, wherein, in step (7), the mercaptan sulfur content of the product obtained is not more than 10 μ g/g.

16. methods according to claim 1,14 or 15, wherein, the method also comprises the last running after desulfurization described in a part that the product that obtains by step (7) replaces the described step (2) contacted with the alkali lye of regeneration in step (5) to obtain.

17. methods according to claim 1, wherein, described gasoline be selected from catalytically cracked gasoline, catalytic cracking gasoline, straight-run spirit, coker gasoline, pyrolysis gasoline and pressure gasoline one or more.