CN100500811C - Process for modifying FCC gasoline distillation and co-producing low-carbon olefine and catalyst thereof - Google Patents

Abstract

A technology for reversion of FCC fraction of gasoline and simultaneous production of lower carbon alkene consists of preheating FCC fraction of gasoline to the reaction temperature, then entering the reactor filled with accelerating agent of modified zeolite molecular sieve to perform gasoline reversion reaction, cooling the reaction product to apply gas-liquid separation, in which the liquid product is modified gasoline and the lower carbon alkene product is obtained by separating gas product. The accelerating agent of modified zeolite molecular sieve is obtained by processing the zeolite molecular sieve at 600-850 DEG C with aqueous vapor for 1-24 hours. The invention has advantages that it can not only solve the problem of reduction of alkenes from FCC gasoline but also can substantially increase the product with a high added value including ethane and propylene, and the economic process technology is good.

Description

FCC distillate gasoline upgrading is produced the technology and the catalyzer of low-carbon alkene simultaneously

Technical field

The invention belongs to a kind of catalyzer and application method, relate in particular to catalyzer and application that a kind of FCC distillate gasoline upgrading is produced low-carbon alkene simultaneously.

Technical background

Along with the continuous reinforcement of global environmental regulation, the contradiction of automobile exhaust pollution and development automotive industry becomes increasingly conspicuous, and causes the great attention of countries in the world.It is one of key that solves this contradiction that fuel oil cleans, from the differentiation of world's gasoline standard, and boosting of octane rating, benzene is taken off in desulfurization, the restriction aromaticity content, reducing olefin(e) centent is the main task of producing clean gasoline from now on.

In China's motor spirit, FCC (fluid catalystic cracking) gasoline proportionality is up to 70～80%, volume fraction of olefins is 45%～50% in the FCC gasoline, the refinery that has is up to 70%, far above gasoline II (volume fraction of olefins ≯ 20%), the III class standard (volume fraction of olefins ≯ 10%) of world fuel standard (WFC), also exist big gap with " the motor spirit objectionable impurities control criterion " of Environmental Protection in China office promulgation in 1999 middle reformulated gasoline standard (volume fraction of olefins ≯ 35%).Therefore, the alkene technology is fallen by common concern in the FCC gasoline.The technical characterictic that FCC decreasing by gasoline olefin catalysis novel process should possess is: 1. it is big to fall the alkene amplitude; 2. loss of octane number is little; 3. high liquid is received and the low hydrogen consumption; 4. technology is simple and have concurrently and take off benzene and desulfurizing function.

Add in the FCC catalyzer that to fall the alkene auxiliary agent be important research direction at present.Domestic Luoyang Petrochemical company refinery has adopted the method that adds the LAP auxiliary agent in catalytically cracked stock, reduces the FCC gasoline olefin.The LAP auxiliary agent has good suitability to raw material.But adopt the method for auxiliary agent less to the contribution that reduces olefin(e) centent usually, account for 5% of catalyst levels～6% o'clock as the LAP auxiliary agent, olefin(e) centent only reduces by 5～8 percentage points in the catalytically cracked gasoline.Add 6%LGO-A and fall alkene auxiliary agent (Jinzhou petrochemical industry stock company and Research Institute of Petro-Chemical Engineering's cooperation research and development) in the FCC catalyzer, can make that olefin(e) centent drops to about 50% by 56.6% in the gasoline, gasoline octane rating slightly improves.

Also can reach the purpose that reduces alkene by optimizing the FCC processing condition.Foreign study shows [Harding R.H., Peters A.W., Nee J.R.D.New Developmentsin FCC Catalyst Technology, [J] .Applied Catalysis A, 2001,221:389-396], reduce riser tube temperature out, dose oil ratio, improve catalyst activity and stablize C in the control gasoline by the degree of depth ₃～C ₄Alkene lighter hydrocarbons content all helps reducing the FCC olefin content in gasoline.

Developing new FCC olefine lowering catalyst is another important research direction in this field.The GOR type FCC catalyzer of domestic petroleum chemical engineering research institute (RIPP) exploitation is used on the FCCU of Luoyang Petrochemical company and high bridge petro-chemical corporation respectively, and olefin(e) centent can reduce by 10.6% and 8.2% respectively in the gasoline.The application on 5 cover FCCU devices of the RFG type FCC catalyzer of external GRACE Davison company exploitation [Hao Daijun. reduce the measure [J] of FCC gasoline olefin. oil refining design, 2001,31 (1): 49-51], can make the FCC content of olefin in gasoline reduce 8%～12%.The advantage of this catalyzer is, reduces the gasoline fraction olefin(e) centent but do not reduce the yield of light olefins such as propylene, butylene, also do not change octane value and catalyst junction charcoal amount.

In order to reduce the FCC content of olefin in gasoline, Akzo Nobel company has proposed a kind of new catalyst technology, be referred to as TOM (Total Olefins Management) Hao Cobra[for army. reduce the measure [J] of FCC gasoline olefin. the oil refining design, 2001,31 (1): 49-51], this technology works by three mechanism: (1) comes saturation of olefins by increasing hydrogen transference; (2) alkene in the gasoline is selected to be cracked into liquefied petroleum gas (LPG) (LPG); (3) the side chain degree of increase stable hydrocarbon or alkene.They think, can realize the increase of hydrogen transference with special zeolite technology, and wherein a part is to realize by the method that increases rare earth content, has also adopted other patented technologies simultaneously.Adopt the ZSM-5 based additive can finish the selective splitting of alkene in the gasoline.This additive can become C with the olefin cracking in the gasoline ₃～C ₄Alkene also helps to recover the loss of octane number that causes because of alkene is saturated.Adopt high silica alumina ratio ADE zeolite can realize the increase of side chain degree.These influence factors are combined, and TOM Cobra can keep 11 percentage points of the constant situation decline low olefin-contents of octane value.

FCC gasoline etherification technology adopts the isomeric olefine reaction in alcohols (methyl alcohol and ethanol) and the FCC gasoline to generate corresponding ether, and making conversion of olefines is a kind of oxygen containing high octane value gasoline blending component.The gasoline etherification technology can improve gasoline octane rating when reducing alkene.The limitation of etherificate technology is, picture isopentene and C in the gasoline ₆Uncle's alkene etc. can only account for the sub-fraction of total olefin with the alkene of methyl alcohol generation etherification reaction, and therefore, structure and the composition that the alkene amplitude is subject to alkene can fall in etherification method, and amplitude is limited generally speaking.

The hydrofining technology also is the important technology that reduces the FCC content of olefin in gasoline, improves gasoline quality.The main purpose of gasoline hydrofinishing is to remove impurity such as wherein sulphur, nitrogen.But alkene may be saturated by hydrogen in unifining process, thereby have the alkene of falling effect simultaneously.SCAN fining technology [Demin R A, et al.[R] .NPRAAM200211. as ExxonMobil company] can make 33%～48% alkene saturated, but loss of octane number is bigger.In addition, the relatively more successful ISAL of Uop Inc. technology [Martine N P, et al.[R] .NPRAAM200252. in addition], it is when the processing catalytic cracking heavy oil, and the deolefination rate reaches 90%, and liquid receives 94%, 7 units of loss of octane number.Domesticly raise the Co-Mo catalyzer and Co-Mo-Ni catalyzer formation composite catalyst that sub-petro-chemical corporation selects Lanzhou Petrochemical Company research institute exploitation for use, be used for the secondary hydrogenation of cracking stock, can make part alkene saturated.

Hydrotreatment hydrogen consumption is big, and the loss of octane number of gasoline is bigger, and this is to reduce the problem that alkene need be considered carefully in the gasoline with the hydrofining method.

Utilize aromatization technology to reduce the FCC content of olefin in gasoline.UOP and BP company and MOBIL company have developed Cyclar and M-2FORMING technology [Nal Y Chen.Ind Eng ChemProcess Des Dev.1986,21:151] has obtained economic benefit.Wherein M2 reformation replacement is a kind of strong method from the reformation of paraffinic base petroleum naphtha production stop bracket gasoline blend component.The productive rate of aromatic hydrocarbons only is subjected to the restriction of hydrogen richness stoichiometric relation in raw material and the product.The key of process is a ZSM-5 type catalyzer, and the related reaction of M-2 has reactions such as cracking, oligomerisation, isomerization, hydrogen transference, cyclisation.And for C ₅～C ₇Between the aromizing research of alkene be not a lot of at home, the aromatization technology that the exploitation of research institute of Shanghai Petrochem. General Plant is arranged early [Shen Lvning. petrochemical complex, 1987,16 (8): 541], with Hydrogen ZSM-5 catalyzer, contain former powder 55%～60%, tackiness agent is γ-Al ₂O ₃, its BTX (BTX aromatics) yield is near 60%, and the one way life-span is greater than 20h.1987, Shanghai research institute of general petrochemicals factory and Danyang, Jiangsu fertilizer plant set up the 3kt/a scale the industrial experiment device [Liu Lujia. refining of petroleum, 1993,24 (1): 26], the used raw material of this reaction is a cracking light oil, and mix 5%～10% C5 fraction, and used catalyzer is the AF-5 molecular sieve catalyst, the transformation efficiency of non-aromatics reaches 90%.Xie Chaogang [Xie Chaogang. refining of petroleum and chemical industry, 1999,30 (11): 6] etc. the people adopt and to select the type zeolite catalyst, on the small stationary bed reaction device, investigated the influence of catalyzer and various condition to the reaction of FCC aromatization of gas.The result shows, at 580 ℃ of temperature of reaction, normal pressure, charging mass space velocity 2.5h ^-1, the agent oil quality than 10 and the water oil quality than under 0.25 the condition, can make the aromatic hydrocarbons massfraction of FCC gasoline bring up to 81.46% from 42.4%.

The alkene aromizing can reduce olefin content in gasoline, satisfies the existing gasoline standard of China.But, consider that China's oil product standard integrates with world's standard of fuel at last, rely on increase aromatic hydrocarbons amount to reduce olefin(e) centent and will be limited in the application in future.

Low-carbon alkene production technology aspect, the rate of growth of world's propylene far can not satisfy propylene growth of requirement speed, particularly in present production of propylene in ethylene process by-product mode, and the growth of ethylene production capacity is incited somebody to action under the main situation based on ethane cracking, and the growth of propylene is subjected to very big restriction.Aspect propylene enhancing, also carried out number of research projects both at home and abroad for this reason.

All there are very big breach in China's ethene, propylene, and the shortage with propylene serves as remarkable especially.According to the reserves and the petrochemical complex industrial structure characteristics of China's oil resource, the approach of at present the most feasible propylene enhancing should be to realize with improvement by the optimization to FCC process and related products.

The amount that conventional FCC apparatus is produced propylene accounts for 3～5% of gross product, and is mainly relevant with the FCC catalyzer with type of feed, operational condition.The propylene that FCC produces accounts for 30% of global propylene amount, and along with steam cracking is produced the minimizing of propylene supply ratio and increased, it was expected that the propylene of FCC production in 2010 will account for 50% of propylene total amount, is the best approach of the minimum benefit of investment by adopting advanced catalyzer, additive and process modification to come propylene enhancing.Therefore improve FCC catalyzer/additive and exploitation advanced technologies is the research and development emphasis of external each major oil companies and catalyst Co. always.

The core that improves FCC process productivity of propylene by catalyzer/additive optimum combination is that the high olefin gasoline fraction that the Primary Catalysts cracking is generated is cracked into propylene to greatest extent.

A FCC apparatus of/3rd is at the additive that uses propylene enhancing in the world, and consumption generally is 2～5%, and at present a lot of refineries addition has reached 10%, makes the FCC apparatus propene yield be increased to 10% from 4.5%.Catalyzer/additive scientific research and development round propylene enhancing mainly solves following three problems:

1. reduce Primary Catalysts rare earth metal content and increase the matrix activity, control hydrogen transference and other secondary reaction to greatest extent.Improve the heavy oil conversion rate, but increase cracked olefin (C ₇ ⁼);

2. research high-performance ZSM-5 or other molecular sieve reduce the diluting effect to Primary Catalysts.(generally speaking, the ZSM-5 molecular sieve of every interpolation 5%, the heavy oil conversion rate descends 1%);

3. by the modification of molecular sieve, improve C ₃In propylene content to reduce the propylene cost recovery;

The world three big FCC catalyzer supply merchant Grace Davison company, Engelhard company and Albemarle company monopolizing the share of FCC catalyzer market more than 95%, at present, this three company all is devoted to the development research of FCC process propylene catalyst with yield increase/auxiliary agent, and has formed technical characteristic separately.

Grace Davison company has developed the maximum propylene catalyst with yield increase of AFEXPMX, and its technical characterstic is:

1. novel type molecular sieve and the substrate material selected that has independent intellectual property rights;

2. be devoted to improve ZSM-5 intrinsic activity, the content of ZSM-5 reaches 25% in the nearest industrialized OlefinsMaxTM additive, has higher activity at the OlefinsUltraTM that grinds;

By novel Primary Catalysts, select the optimization of type molecular sieve and operational condition, the AFE technology of propylene enhancing is proposed.

The MPA additive of Engelhard company is based on that the DMS technology platform develops, and has high heavy oil cracking activity and selectivity.But by the production cracked straight chain of maximum or the alkene of band methyl branch, thereby realize that propene yield is the highest, gasoline loss and coke selectivity are minimum.

Three notable features of DMS technology platform are:

1. substrate material provides optimum pore distribution for the diffusion and the cracking of heavy oil molecules;

2. pre-cracking occurs in zeolite crystal outside surface-molecular sieve shape slective cracking, rather than carries out nonselective cracking on [amorphous;

3. matrix and molecular sieve combination technology make the zeolite crystal high dispersing at matrix hole surfaces externally and internally, and this special pattern makes catalyzer have high reaction activity and low coke selectivity.

Catalyzer/additive technology the characteristics of Albemarle (refined treasured) company exploitation are:

1. (B.O.O.S.T of Albemarle) will suitably improve propene yield when measuring during high reactivity ZSM-5 additive adds;

2. (Albemarle Z.O.O.M) can obtain maximum propene yield when adding maximum amount, and can the dilute catalyst activity.This additive integrates so-called AFX technology with advanced Primary Catalysts optimization, when not influencing the heavy oil conversion rate, and propylene enhancing to greatest extent.

In addition, the SCC technology is ABBLummus company exploitation high severity FCC is operated and petroleum naphtha component selective cracking and olefin metathesis technical combinations complete set technology together.The characteristics of this technology comprise: newest F CC catalyzer is used in combination with high density ZSM-5, in order to satisfy the harsh requirement of higher operation, adopted Micro-Jet feed nozzle and associated mode coupling cyclonic separator, the propene yield of this technology depends on the quantity of raw material, FCC catalyst type and used ZSM-5.Mobil company adopts the ZSM-5 zeolite to develop Maxofin technology cooperatively as the FCC additive and with Kellogg company, combine with the FCC apparatus of high-content ZSM-5 additive with the advanced person, its objective is and need not adopt harsh operational condition and improve steam consumption, just can make Minas decompression diesel oil reach 18% as the propene yield of raw material; The Petro FCC technology of Uop Inc.'s exploitation is based on the RxCat technology and reaches high cracking severity, and it transmits reactor catalyst with circular route and turns back to riser tube, has improved riser tube agent/oil quality ratio, and experiment shows that productivity of propylene can surpass 20%; Superflex technology also is the technology that can improve propene yield, have economy by the exploitation of Arco chemical company.This method can be converted into propylene with the low-quality lighter hydrocarbons based on the fluid catalytic cracking technology of having verified.It can handle C ₄～C ₈Petroleum fractions, the abundant raw material of olefin(e) centent has higher transformation efficiency and to the selectivity height of propylene, it can be ethene and propylene with 2/3rds feedstock conversion almost, also this technology and ethylene unit can be combined to improve the output capacity of total propylene, ethene.

Domestic aspect, the DCC technology of China Petroleum ﹠ Chemical Corporation, Petroleum Chemical Engineering Institute (RIPP) exploitation is considered to solve an effective way of propylene shortage of resources.This process utilizes wax oil to be raw material, produces low-molecular olefine under 538～582 ℃, 10%～30% steam condition.Difference according to catalyst system therefor is divided into maximum propylene and two kinds of schemes of maximum isomeric olefine; The FDFCC technological process is the exploitation of research institute of Luoyang Petrochemical engineering corporation, adopt the double lifting leg technical process respectively inferior heavy oil to be carried out catalytic reforming with gasoline under different processing condition, not only can increase substantially the efficient of gasoline upgrading, also avoid the operation of heavy oil catalytic cracking riser reactor is brought any disadvantageous effect.Propylene enhancing and liquefied gas that simultaneously can be relatively large, productivity of propylene can improve 3～6 percentage points.

The technology of above propylene enhancing differs from one another, and can both reach the purpose of propylene enhancing under given conditions.The subject matter that exists is:

Restrict it as the addition of additive in catalyzer 1.ZSM-5 the molecular sieve intrinsic is active, thereby restriction improves the amplitude of productivity of propylene.The ZSM-5 molecular sieve can be optionally is low-carbon alkenes such as ethene, propylene with the olefin cracking of FCC process gasoline fraction, and with the increase of ZSM-5 addition, the productive rate of low-carbon alkene improves.But, when the ZSM-5 molecular sieve adds in the FCC catalyzer as additive,, must cause the cracking catalyst activity to reduce because catalyzer is produced diluting effect because ZSM-5 molecular sieve lytic activity is low than Y zeolite.The ZSM-5 molecular sieve of common every adding 5%, the heavy oit pyrolysis transformation efficiency reduces by 1 percentage point, and the reduction of heavy oil conversion rate is the important factor that has a strong impact on the FCC Technological Economy.

2.ZSM-5 the hydrothermal stability of molecular sieve is difficult to satisfy the processing condition of FCC process harshness, has limited it as Application of Additives.The FCC process is carried out in the presence of high temperature (500～600 ℃) and water vapor, and the temperature of FCC continuous catalyst regenerating more reaches more than 800 ℃.The ZSM-5 molecular sieve is under exacting terms like this, and bad stability often occurs that lattice subsides and the problem of structure deteriorate, and thus, the hydrothermal stability that improves the ZSM-5 molecular sieve becomes the another one key that is introduced into the FCC catalyzer and realizes producing more propylene;

3. in propylene enhancing, do not take into account FCC content of olefin in gasoline problem.

In sum, existing FCC falls alkene technology and FCC process propylene enhancing technology when acquisition of technology progress separately, can solving separately problem preferably, also has defective separately.Common ground is:

1. above-mentioned technology is all directly changed the FCC process, or the adjustment of operating parameters, or change FCC catalyzer is formed, because the FCC apparatus scale is big, the operation easier height, FCC is carried out the change of processing condition and catalyzer and often will emit huge risk, therefore restricted the exploitation and the process of industrialization of new technology to a certain extent;

2. falling alkene technology and propylene enhancing technology does not have and can take into account mutually, fall the alkene technology and can not improve productivity of propylene, and the producing more propylene technology can not solve FCC content of olefin in gasoline problem.

Up to the present, also there is not a kind of technology can reach the dual purpose that reduces FCC content of olefin in gasoline and propylene enhancing simultaneously.

The content of invention

One of purpose of the present invention provides the catalyzer that a kind of FCC distillate gasoline upgrading is produced low-carbon alkene simultaneously.

Another object of the present invention provides the technology that a kind of FCC distillate gasoline upgrading is produced low-carbon alkene simultaneously, is characterized in that highly selective is produced low-carbon alkenes such as ethene and propylene when reducing content of olefin in gasoline significantly.

Novel process provided by the invention is a kind of technology of processing at FCC distillate gasoline product, does not relate to the processing parameter and the catalyst system of FCC process itself.

Fall in the experimentation of alkene auxiliary agent at research FCC catalyzer, adopt FCC gasoline light fraction to carry out the active investigation of zeolite molecular sieve auxiliary agent pyrolysis gasoline fraction alkene, find through the proper method preparation, and the molecular sieve catalyst of the suitable modification of process, in the product that when carrying out the cracking of gasoline fraction alkene, is produced, ethene, the selectivity of low-carbon alkenes such as propylene is very high, and dry gas methane, selectivity such as ethane are very low, thereby a kind of FCC distillate gasoline upgrading novel process has been proposed, adopt the catalyzer of method preparation provided by the invention to carry out FCC distillate gasoline upgrading, both can reduce the FCC content of olefin in gasoline significantly, can highly selective produce low-carbon alkene again.

Catalyzer provided by the invention is to carry out modification through zeolite molecular sieve, its method of modifying be with zeolite molecular sieve under 600～850 ℃ of conditions, with steam treatment 1～24 hour.

Aforesaid zeolite molecular sieve is the ZSM-5 molecular sieve, the ZSM-11 molecular sieve is (referring to United States Patent (USP) U.S.Pat.No.3,709,9790), the ZSM-12 molecular sieve is (referring to United States Patent (USP) U.S.Pat.No.3,832,449), the ZSM-23 molecular sieve is (referring to United States Patent (USP) U.S.Pat.No.4,076,842), the ZSM-35 molecular sieve is (referring to United States Patent (USP) U.S.Pat.No.4,016,245), the ZSM-38 molecular sieve is (referring to United States Patent (USP) U.S.Pat.No.4,046,859), the ZSM-48 molecular sieve is (referring to United States Patent (USP) U.S.Pat.No.1,375,573) etc., preferably preferred ZSM-5 molecular sieve.

The preparation method of ZSM-5 molecular sieve can be referring to Chinese invention patent ZL00109593.5: the method for directing agent method fast synthesis of ZSM-5-5 molecular sieve, ZL99124634.5: a kind of strong acid type ZSM-5 zeolite catalyst and preparation method thereof, ZL0255482.X: a kind of method of fast synthetic strong acid type ZSM-5 molecular sieve etc.

The ZSM-5 molecular sieve that catalyzer provided by the invention adopted preferably has the tiny crystal grains structure, the synthetic technology of tiny crystal grains ZSM-5 molecular sieve is referring to Chinese patent ZL98123933.1: a kind of crystal grain is less than the preparation method of the FeZSM-5 zeolite molecular sieve of 1 μ m, and this ZSM-5 molecular sieve catalyst has following basic characteristics:

(1) the atom short distance is arranged in order, belongs to crystal;

(2) the transmission performance is better, helps improving reaction preference;

(3) the plug-hole deactivation rate is slower, helps keeping high reactivity;

(4) duct is short, helps charcoal regeneration and improves utilization rate of inner surface.

Tiny crystal grains ZSM-5 molecular sieve catalyst is compared with common zeolite molecular sieve, and the micropore restricted index is less, and the shared ratio in outside surface and acid site, aperture surpasses 30% (common ZSM-5 molecular sieve only reaches 3%).This just generates low-carbon alkene for a large amount of alkene in the FCC distillate gasoline raw material and low-octane normal paraffin by scission reaction, highly selective and isoparaffin provides favourable reaction and diffusional environment.

Adopt method provided by the invention to carry out Preparation of Catalyst, at high temperature processing has following effect to zeolite molecular sieve with water vapour:

(1). remove zeolite [molecular sieve and remain in micro-acid and the fragment educt that seals in the duct, the micro pore volume of zeolite molecular sieve is improved in the blocked duct of mediation part, thereby improves the catalytic activity of molecular sieve catalyst;

(2). remove framework aluminum, weaken the acidity of molecular sieve, reduce the ratio of strong and weak acid, help the aromizing effect in the inhibited reaction process;

(3). improve the catalyzer silica alumina ratio, reduce the molecular sieve carbon distribution, strengthen the warm qualitative of catalyzer.

The concrete steps that FCC distillate gasoline upgrading provided by the invention is produced the technology of low-carbon alkene simultaneously are:

1. raw material FCC distillate gasoline is preheated to temperature of reaction;

2. the material after the preheating enters in the reactor that the modified zeolite molecular sieve catalyzer is housed, and carries out the reaction of distillate gasoline upgrading;

3. after the reaction product of coming out from reactor cools, carry out gas-liquid separation;

4. separate the liquid product that obtains and be the reformulated gasoline product;

5. the gaseous product separation obtains the low-carbon alkene product;

The raw material of process using provided by the invention is the light fraction of FCC gasoline, and preferably boiling point is less than 75 ℃ fraction, and contained component is C substantially ₇And carbon number hydro carbons still less.Alkene in the FCC gasoline mainly concentrates on this fraction section.Table 1 is that the typical case of China FCC gasoline forms.

The carbon number distribution of table 1. China typical case FCC gasoline and hydrocarbon system's composition [Zhang Jianqiu. the catalytic cracking novel material that reduces content of olefin in gasoline is explored. Beijing: Research Institute of Petro-Chemical Engineering, 2001]

Project	n-P	i-P	0	N	A	SUM/(wt％)
							C 4	0.46	0.61	3.48	0	0	4.55
C 5	0.83	5.32	10.92	0.13	0	17.20
							C 6	0.63	4.66	9.36	1.64	0.66	16.95
C 7	0.42	3.76	7.12	2.76	3.22	17.28
							C 8	0.90	3.07	4.38	2.20	7.32	17.87
C 9	0.31	2.37	1.99	1.51	9.20	15.38
							C 10	0.35	1.89	0.85	0.38	5.13	8.60
C 11	0.19	1.20	0.31	0.04	0.29	2.03
							C 12	0	0.10	0.04	0	0	0.14
TOTAL/(wt％)	4.09	22.98	38.45	8.66	25.82	100.00

In the technology provided by the invention, the liquid air speed of FCC distillate gasoline is 0.1h ^-1～6h ^-1

Technology provided by the invention is carried out under normal pressure, and for ensureing material effectively flowing in reactive system, reaction pressure can be adjusted in 0.1～1.0MPa scope.

Technology upgrading temperature of reaction provided by the invention is 450～650 ℃.

In the technology provided by the invention, gaseous product adopts conventional separation means.

FCC distillate gasoline upgrading provided by the invention is produced low-carbon alkene technology simultaneously, mainly is that the reactions such as cracking, isomery, aromizing by the FCC distillate gasoline realize.Alkane in the FCC distillate gasoline is main generation isomerization reaction in the upgrading reaction, makes the normal paraffin in the raw material be converted into isoparaffin.Scission reaction mainly takes place in the alkene in the FCC distillate gasoline, generates low-carbon alkenes such as ethene, propylene, has a spot of alkene generation aromatization to generate aromatic hydrocarbons simultaneously.

Adopt technology provided by the invention and use catalyzer provided by the invention, the olefin(e) centent of FCC distillate gasoline can reduce by 20～50 percentage points, and the alkene total content can be reduced to 5～30%.Alkane in the product gasoline is based on isomerized products.

Adopt technology provided by the invention and use catalyzer provided by the invention, the gas-phase product that FCC distillate gasoline upgrading reaction is produced is based on low-carbon alkene, wherein C ₂～C ₄Alkene accounts for the gas-phase product weight percent more than 80%, and accounting for raw material FCC distillate gasoline weight percent is 10%～30%.

In low-carbon alkene, propylene is a main products, and weight percent is 50%～65% in all low-carbon alkenes.It is 10%～20% that propylene accounts for raw material FCC distillate gasoline weight percent.

At gas phase C ₂In the product, weight ethylene per-cent is 75%～95%.

At gas phase C ₃In the product, propylene weight per-cent is 85%～95%.

At gas phase C ₄In the product, propylene weight per-cent is 60%～85%.

Dry gas (methane+ethane) accounts for the gas-phase product weight percent below 5%, accounts for FCC distillate gasoline weight percent below 1%.

LPG (propane+butane) accounts for gas-phase product weight percent 10～15%, accounts for FCC distillate gasoline weight percent below 4%.

The purpose that the present invention reduces content of olefin in gasoline be by alkene at zeolite [molecular sieve, realize as the cracking on the ZSM-5 molecular sieve catalyst and a small amount of aromatization.Can see C from the research octane number (RON) data of table 2 different hydrocarbons ₅, C ₆, C ₇Alkene has very high octane value, and the olefine reaction that falls of the present invention mainly occurs in these this cut sections, therefore, can be lost by the octane value that alkene provides.The aromatization of small amounts of olefins improves aromaticity content.Table 2 data show that aromatic hydrocarbons has very high octane value, make the octane value of product gasoline obtain the part compensation thus.The isomerization reaction of normal paraffin takes place in the FCC distillate gasoline upgrading novel process provided by the invention simultaneously, and from table 2 data as can be seen, the octane value of isoparaffin can further compensate the loss of octane value thus than the normal paraffin height of same carbon number.

Adopt the inventive method to carry out the product gasoline that FCC distillate gasoline upgrading is produced low-carbon alkene simultaneously and produced, octane value does not lose or loses very little on the whole.

The research octane number (RON) of table 2. different hydrocarbons

RON	C5	C6	C7	C8	C9	C10
							n-paraffin		25	0	17	19	41
i-paraffin	～100	73～92	42～93	22～100	～50	86～94
							Olefin	90～118	～76	～142
Aromatics		99	124	124～146	127～171	114～138

The superiority of novel process provided by the invention is:

1. novel process provided by the invention is a kind of technology of processing at the FCC gasoline products, the processing parameter and the catalyst system of FCC process itself is not changed, and is workable, easily implements;

2. gasoline upgrading technology provided by the invention has been taken into account two problems of low-carbon alkene such as FCC decreasing by gasoline olefin and producing more propylene;

3.FCC it is big that distillate gasoline alkene reduces amplitude.Olefin(e) centent can reduce by 20～50 percentage points, and the olefin(e) centent in the product gasoline can be reduced to 5～30%;

4. effective product yield height.Gasoline+low-carbon alkene mass yield is greater than 95%, and the dry gas mass yield is less than 1%;

5. ethene, propylene selectivity height in the gas-phase product help reducing separation costs;

6. process does not have the hydrogen consumption, and the cost of having avoided the hydrogen consumption to be brought increases problem;

7. can be when solving FCC decreasing by gasoline olefin problem, the product of high additive value such as increasing output of ethylene, propylene significantly, process technology good economy performance.

Embodiment

Embodiment 1

1. Preparation of Catalyst

1.1 tiny crystal grains ZSM-5 molecular sieve is synthetic

Be SiO in molar ratio at first with silicon source, sodium salt and deionized water ₂: Na ₂O: H ₂O=0.02:0.004:1 is mixed with A solution; Aluminium source, acid and deionized water are the aluminium source in molar ratio: acid: deionized water=0.0002:0.01:1 is mixed with B solution; Zirconium source, deionized water are mixed with C solution for zirconium source: deionized water=0.0004:1 in molar ratio, source of iron: deionized water=0.0004:1 is mixed with D solution.

Batching is operation in the following order: under vigorous stirring, 200ml B drips of solution is added in the 500ml A solution, stirs.Add 14.95g tetraethyl-amine bromide then, add the 200ml solution C again, then add the 200ml solution D, stir and it was mixed in 30 minutes.At last the mixture for preparing is transferred in the synthesis reactor and seals.Beginning is warming up to 100 ℃ with the temperature rise rate of 1 ℃/min, keeps constant temperature 40 hours.Continue to be warming up to 160 ℃ with the temperature rise rate of 1 ℃/min, constant temperature can be finished in 30 hours again.Cool off rapidly with frozen water, stop crystallization, the mixture in the synthesis reactor is shifted out.

Said mixture is carried out after the solid-liquid separation with deionized water wash to filtrate pH=8～9.Drying is 12 hours under 120 ℃, can obtain molecular screen primary powder, and its mean grain size is 0.52 μ m.Remove template 540 ℃ of following roastings then.Carry out ion-exchange 2 times with the hydrochloric acid soln of 0.1mol/L in 80 ℃ again, each 1 hour, at last with deionized water washing 5 times, oven dry in 120 ℃ in baking oven obtained the FeZrHZSM-5 molecular sieve in 8 hours through 540 ℃ of roastings; The pseudo-boehmite that adds 35 (wt) % then, (v) the salpeter solution of % mixes, and extruding slivering column type after the oven dry, places stoving oven in 540 ℃ of following roastings 5 hours in 100 ℃ of baking ovens then, is broken for 20-40 orders in employing 2.

1.2 molecular sieve catalyst modification

Above-mentioned molecular sieve catalyst is used steam treatment 10 hours down at 750 ℃.The physical parameter of zeolite molecular sieve sees Table 3 before and after the steam treatment.

Parameter changes before and after the table 3 embodiment 1 zeolite molecular sieve steam treatment

The zeolite molecular sieve parameter	Void volume (ml/g)	Strong acid/weak acid	Si/Al
				Before the processing	0.140	2.5	25
After the processing	0.150	2.0	35

2. upgrading raw material FCC distillate gasoline preparation

The FCC gasoline that to take from North China Oilfield factory carries out simple distillation, gets boiling point＜70 ℃ fraction as raw material.The raw material composition sees Table 4.

Table 4 FCC distillate gasoline is formed

Carbon number	Alkane	Alkene	Naphthenic hydrocarbon	Aromatic hydrocarbons	∑
						4	0.63	4.43	-	-	5.06
5	16.12	23.37	-	-	39.49
						6	21.07	10.72	0.48	-	32.27
7	8.26	5.17	-	4.13	17.56
						8	2.85	0.17	-	2.60	5.62
∑	48.93	43.86	0.48	6.73	100

3.FCC the distillate gasoline upgrading is produced low-carbon alkenes such as ethene, propylene simultaneously

The molecular sieve catalyst 5ml of above-mentioned preparation is packed in the fixed-bed reactor, bed temperature is risen to 500 ℃, under 0.1MPa, with volume pump ready raw material metering is squeezed in the reactor, control raw material air speed LHSV=1h-1, reaction product obtains the reformulated gasoline product after water-cooled, gas-liquid separation.Gas-phase product adopts the rectifying separation means to obtain low-carbon alkene products such as ethene, propylene, butylene, and dry gas (methane, ethane) and LPG (propane, butane).Reaction result sees Table 9, and the gas-phase product composition sees Table 10.

Embodiment 2

1. Preparation of Catalyst

1.1 tiny crystal grains ZSM-5 molecular sieve is synthetic

With embodiment 1, but do not add zirconium source and source of iron, obtain the HZSM-5 molecular sieve, mean grain size is 0.45 μ m.

1.2 molecular sieve catalyst modification

Above-mentioned molecular sieve catalyst is used steam treatment 24 hours down at 850 ℃.The physical parameter of zeolite molecular sieve sees Table 5 before and after the steam treatment.

Parameter changes before and after the table 5 embodiment 2 zeolite molecular sieve steam treatment

The zeolite molecular sieve parameter	Void volume (ml/g)	Strong acid/weak acid	Si/Al
				Before the processing	0.140	2.5	25
After the processing	0.175	1.0	70

2. upgrading raw material FCC distillate gasoline preparation

With embodiment 1

3.FCC the distillate gasoline upgrading is produced low-carbon alkenes such as ethene, propylene simultaneously

With embodiment 1, but temperature of reaction is when being 540 ℃, and pressure is 0.5MPa, raw material air speed LHSV=3h ^-1, the reaction result of embodiment 2 sees Table 9, and the gas-phase product composition sees Table 10.

Embodiment 3

1. Preparation of Catalyst

1.1 tiny crystal grains ZSM-5 molecular sieve is synthetic

With embodiment 1, but do not add the zirconium source, obtain the FeHZSM-molecular sieve, mean grain size is 0.48 μ m.

1.2 molecular sieve catalyst modification

Above-mentioned molecular sieve catalyst under 800 ℃, is used steam treatment 20 hours.The physical parameter of zeolite molecular sieve sees Table 6 before and after the steam treatment.

Parameter changes before and after the table 6 embodiment 3 zeolite molecular sieve steam treatment

The zeolite molecular sieve parameter	Void volume (ml/g)	Strong acid/weak acid	Si/Al
				Before the processing	0.140	2.5	25
After the processing	0.170	0.9	60

2. the preparation of upgrading raw material FCC distillate gasoline is with embodiment 1

3.FCC the distillate gasoline upgrading is produced low-carbon alkenes such as ethene, propylene simultaneously

With embodiment 1, but temperature of reaction is when being 550 ℃, and pressure is 1.0MPa, raw material air speed LHSV=1h ^-1, the reaction result of embodiment 3 sees Table 9, and the gas-phase product composition sees Table 10.

Embodiment 4

1.1 tiny crystal grains ZSM-5 molecular sieve is synthetic

With embodiment 1.

1.2 molecular sieve catalyst modification

Above-mentioned molecular sieve catalyst under 800 ℃, is used steam treatment 24 hours.The physical parameter of zeolite molecular sieve sees Table 7 before and after the steam treatment.

Parameter changes before and after the table 7 embodiment 4 zeolite molecular sieve steam treatment

The zeolite molecular sieve parameter	Void volume (ml/g)	Strong acid/weak acid	Si/Al
				Before the processing	0.140	2.5	25
After the processing	0.168	1.3	50

2. upgrading raw material FCC distillate gasoline preparation

With embodiment 1

3.FCC the distillate gasoline upgrading is produced low-carbon alkenes such as ethene, propylene simultaneously

With embodiment 1, but temperature of reaction is when being 560 ℃, and pressure is 0.3MPa, raw material air speed LHSV=1h ^-1, the reaction result of embodiment 4 sees Table 9, and the gas-phase product composition sees Table 10.

Embodiment 5

1.1 the ZSM-5 molecular sieve is synthetic

Getting commodity ZSM-5 molecular screen primary powder is the catalyzer raw material.

1.2 molecular sieve catalyst modification

Above-mentioned molecular sieve catalyst under 800 ℃, is used steam treatment 16 hours.The physical parameter of zeolite molecular sieve sees Table 8 before and after the steam treatment.

Parameter changes before and after the table 8 embodiment 5 zeolite molecular sieve steam treatment

The zeolite molecular sieve parameter	Void volume (ml/g)	Strong acid/weak acid	Si/Al
				Before the processing	0.130	3.5	50
After the processing	0.148	1.5	80

2. upgrading raw material FCC distillate gasoline preparation

With embodiment 1

3.FCC the distillate gasoline upgrading is produced low-carbon alkenes such as ethene, propylene simultaneously

With embodiment 1, but temperature of reaction is when being 540 ℃, and pressure is under the 0.1MPa, raw material air speed LHSV=1h ^-1, the reaction result of embodiment 5 sees Table 9, and the gas-phase product composition sees Table 10.

Table 9 embodiment 1～5 reaction result

The embodiment numbering	1	2	3	4	5
						Total olefin transformation efficiency (wt%)	52.38	39.47	68.36	71.69	32.25
Yield of gasoline (wt%)	76.55	82.33	69.40	67.90	85.56
						Gaseous products yield (wt%)	23.45	17.67	30.60	32.10	14.44
Overall material balance (wt%)
						Gasoline	76.55	82.33	69.40	67.90	85.56
Methane	0.92	0.08	0.39	052	0.44
						Ethene	3.71	2.80	2.45	3.98	1.66
Ethane	1.16	0.29	0.36	0.35	0.25
						Propylene	9.18	8.88	16.54	15.69	8.00
Propane	1.31	0.64	0.99	1.64	0.39
						Butylene	5.42	3.00	7.78	8.45	2.74
Butane	1.75	1.98	2.08	1.48	0.95
						Add up to	100	100	100	100	100
C2＝+C3＝(wt％)	12.89	11.68	18.99	19.66	9.66
						C2＝+C3＝+C4＝(wt％)	18.31	14.67	26.78	28.11	12.40
Dry gas (methane+ethane) (wt%)	2.08	0.37	0.75	0.87	0.69
						LPG (propane+butane) (wt%)	3.06	2.62	3.07	3.1	1.34
Product gasoline group composition (wt%)
						P	52.73	40.66	60.98	68.29	58.8
O	21.32	27.1	15.36	10.68	30.33
						A	12.59	32.33	23.66	18.03	9.15

Table 10 embodiment 1～5 gas-phase product is formed

The embodiment numbering	1	2	3	4	5
						Methane (wt%)	3.9	0.48	1.28	1.63	3.06
Ethene (wt%)	15.84	15.82	8.02	12.39	11.50
						Ethane (wt%)	4.95	1.64	1.19	1.09	1.76
Propylene (wt%)	39.13	50.27	54.05	48.87	55.42
						Propane (wt%)	558	3.64	325	5.1	2.67
Butylene (wt%)	23.11	16.95	25.43	26.31	19.00
						Butane (wt%)	7.48	11.2	6.79	4.6	6.60
C2＝+C3＝(wt％)	54.97	66.09	62.07	61.26	66.91
						C 2 ＝+C 3 ＝+C 4 ＝(wt％)	78.08	83.04	87.50	87.57	85.91
C 2 ＝/C 2	0.76	0.91	0.87	0.92	0.87
						C 3 ＝/C 3	0.88	0.93	0.94	0.91	0.95
C 4 ＝/C 4	0.76	0.60	0.79	0.85	0.74
						C 3 ＝/(C 2 ＝+C 3 ＝+C 4 ＝)	0.50	0.61	0.62	0.56	0.65
Dry gas (methane+ethane) (wt%)	8.85	2.12	2.47	272	4.81
						LPG (propane+butane) (wt%)	13.06	14.84	10.04	9.70	9.27

Claims (4)

1. the technology that FCC distillate gasoline upgrading is produced low-carbon alkene simultaneously is characterized in that comprising the steps:

(1) the raw material boiling point being preheated to temperature of reaction less than 75 ℃ FCC distillate gasoline is 450～650 ℃;

(2) material after the preheating enters in the reactor that the modified zeolite molecular sieve catalyzer is housed, and is 0.1h in the liquid air speed ^-1～6h ^-1, pressure is under the condition of normal pressure, carries out the reaction of distillate gasoline upgrading;

(3) after the reaction product of coming out from reactor cools, carry out gas-liquid separation;

(4) separate the liquid product that obtains and be the reformulated gasoline product;

(5) the gaseous product separation obtains the low-carbon alkene product;

Described modified zeolite molecular sieve is ZSM-5 molecular sieve, ZSM-11 molecular sieve, ZSM-12 molecular sieve, ZSM-23 molecular sieve, ZSM-35 molecular sieve, ZSM-38 molecular sieve or ZSM-48 molecular sieve, under 600～850 ℃ of conditions, the modified zeolite molecular sieve catalyzer that obtains after 1～24 hour with steam treatment.

2. the technology that a kind of FCC distillate gasoline upgrading as claimed in claim 1 is produced low-carbon alkene simultaneously is characterized in that described normal pressure adjusts in 0.1～1.0MPa scope.

3. the technology that a kind of FCC distillate gasoline upgrading as claimed in claim 1 is produced low-carbon alkene simultaneously is characterized in that described zeolite molecular sieve is the ZSM-5 molecular sieve.

4. the technology that a kind of FCC distillate gasoline upgrading as claimed in claim 1 is produced low-carbon alkene simultaneously is characterized in that described ZSM-5 molecular sieve is the FeZSM-5 zeolite molecular sieve of crystal grain less than 1 μ m.