CN100532335C - Method for producing ethylene and propylene by fluidized catalytic cracking - Google Patents

Abstract

The invention relates to a method of producing ethylene and propylene by fluidized bed catalytic cracking, and mainly solves the problem that when producing the ethylene and the propylene by naphtha catalytic cracking, reaction temperature is high, activity of catalyst is low when at low temperature and yield of ethylene and propylene is low. The invention adopts naphtha of C4-C10 hydrocarbon as raw material to produce the ethylene and the propylene by catalytic cracking in reaction conditions of temperature of 550 - 700 DEG C, reaction pressure of 0.001 to 0.5MPa, weight space velocity of 0.1 to 4h<-1> and weight ration of water to naphtha of 0.5 to 4:1. The catalyst technical proposal is that SiO2 or at least one of compound molecular sieves is adopted as a carrier, containing compound of which a chemical formula based on atomic ratio calculation is Mo1.0VaAbBcCdOx, wherein A is at least one of VIII, IB, IIB, VIIB, VIB, IA or IIA that are selected from periodic table of chemical elements, B is at least one of lanthanons and C is catalyst that is at least one of Bi or P, thereby properly solving the problem. The invention is used for industrial production of the ethylene and the propylene by naphtha catalytic cracking.

Description

Method for producing ethylene and propylene by fluidized catalytic cracking

technical field

The invention relates to a method for producing ethylene and propylene by fluidized bed catalytic cracking.

Background technique

With the development of society, the market demand for ethylene propylene in my country has increased sharply, the import volume of ethylene propylene and its downstream products has increased year by year, and the market share of domestic products is less than half. At present, ethylene in the world mainly uses naphtha (or ethane) as raw material and adopts steam pyrolysis technology (at a temperature of about 800°C) to produce ethylene, and its output exceeds 90% of the total output. Compared with steam thermal cracking, the reaction temperature of catalytic cracking is about 50-200℃ lower than that of standard cracking reaction, so the energy consumption is less than that of ordinary steam cracking, and the coking rate of the inner wall of cracking furnace tube will be reduced, which can prolong the operation period and increase Furnace tube life; carbon dioxide emissions will also be reduced, and the product structure can be adjusted flexibly, the total yield of ethylene and propylene can be increased, and the production cost of ethylene is greatly reduced. Therefore, finding a suitable cracking catalyst to overcome the above-mentioned shortcomings has become more and more concerned.

The patents US4620051 and US4705769 of the Phillips Corporation of the United States use manganese oxide or iron oxide as the active component, adding rare earth element La and alkaline earth metal Mg oxide catalyst to crack C ₃ and C ₄ raw materials. Mn, Mg/Al ₂ O ₃ catalyst in a laboratory fixed bed reactor, 700 ° C, the molar ratio of water and butane is 1:1, the conversion of butane can reach 80%, the selectivity of ethylene and propylene for 34% and 20%. Both patents state that naphtha and fluidized bed reactors can also be used.

U.S. Patent USP6211104 adopts a catalyst containing 10-70% by weight of clay, 5-85% by weight of inorganic oxides, and 1-50% by weight of molecular sieves. Activity of light olefins, especially ethylene. The molecular sieve used is 0-25 wt% Y zeolite with high silicon-aluminum ratio or ZSM molecular sieve with MFI structure impregnated with phosphorus/Al, Mg or Ca, but the selectivity and yield of ethylene propylene of the catalyst are not high.

The patent CN1317546A of Italian Ennichem Company relates to a steam cracking reaction catalyst with a chemical formula of 12CaO·7Al ₂ O ₃ . Naphtha can be used as the raw material, the operating temperature is 720-800°C, the contact time is 0.07-0.2 seconds under the pressure of 1.1-1.8 atmospheres, and the yield of ethylene and propylene can reach 43%.

Japan Asahi Kasei (patent CN1274342A) has announced a molecular sieve with a high silicon-aluminum ratio and a pore size between 0.5-0.65 nanometers as a catalyst to prepare ethylene propylene from light hydrocarbons containing olefins, but the yield of ethylene propylene is low.

Exxon Mobil (00816642.0) announced a zeolite with a pore size of less than 0.7 nanometers to treat naphtha-containing hydrocarbon feedstock to produce ethylene propylene at 550-600° C., and the conversion rate of the feedstock is relatively low.

The former Soviet patent USSR Pat1298240.1987 uses Zr ₂ O ₃ loaded on pumice or ceramics, the space velocity on a medium-sized device at a temperature of 660-780°C is 2-5 hours ^-1 , and the water/naphtha weight ratio is 1:1. Using normal alkanes C _7-17 , cyclohexane, and straight-run gasoline as raw materials, the yield of ethylene can reach 46%, and that of propylene can reach 8.8%.

Chinese patent CN1480255A introduces an oxide catalyst, using naphtha as a raw material, catalytic cracking at 780°C to produce ethylene and propylene, and the yield of ethylene plus propylene can reach 47%.

To sum up, the existing catalytic cracking technology for producing ethylene and propylene has relatively high reaction temperature, but the yield of ethylene and propylene does not increase significantly.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the problems of high reaction temperature, low activity and poor selectivity of the catalyst used in the existing catalytic cracking technology, and provide a new method for producing ethylene and propylene by fluidized bed catalytic cracking , using this method to catalytically crack naphtha to produce ethylene propylene has the advantages of lowering the catalytic cracking temperature and maintaining a high yield of ethylene propylene.

In order to solve the above-mentioned technical problems, the technical scheme adopted in the present invention is as follows: a method for producing ethylene and propylene by fluidized bed catalytic cracking, using naphtha whose components are C ₄ ~C ₁₀ hydrocarbons as raw material, at a reaction temperature of 550 ~700°C, reaction pressure 0.001~0.5MPa, weight space velocity 0.1~4h ^-1 , water/naphtha weight ratio 0.5~4:1, the catalytic cracking reaction produces ethylene propylene, wherein Described catalyzer is selected from _SiO at least one in or composite molecular sieve is carrier, contains the following composition of chemical formula in terms of atomic ratio:

Mo _1.0 V _a A _b B _c C _d O _x

In the formula, A is selected from at least one element in Group VIII, Group IB, Group IIB, Group VIIB, Group VIB, Group IA or Group IIA of the Periodic Table of Elements;

B is selected from at least one of the rare earth elements;

C is selected from at least one of Bi or P;

The value range of a is 0.01~0.5;

The value range of b is 0.01~0.5;

The value range of c is 0.01~0.5;

The value range of d is 0.01～0.5;

X is the total number of oxygen atoms required to satisfy the valence of each element in the catalyst;

The composite molecular sieve is a composite grown together by at least two molecular sieves selected from ZSM-5, Y, β or mordenite;

Wherein the catalyst carrier consumption is 20～80% of catalyst weight in percent by weight; The preferred version of the VIII group element is at least one selected from Fe, Co or Ni; The preferred version of the IB group element is selected from Cu or Ag. At least one; The preferred version of the IIB group element is selected from Zn; the VIIB group element is selected from at least one of Mn or Re; the VIB group element is selected from at least one of Cr, Mo or W; the preferred version of the IA group element is At least one selected from Li, Na or K; the preferred version of the IIA element is at least one selected from Ca, Mg, Sr or Ba; the preferred version of the rare earth element is at least one selected from La or Ce. .

In the above technical solution, the preferred range of a is 0.01-0.3; the preferred range of b is 0.01-0.3; the preferred range of c is 0.01-0.3; the preferred range of d is 0.01-0.3. When Cr is contained in the catalyst composition, the atomic ratio of Mo:Cr is 1:0.01-0.5. A preferred solution of the catalyst carrier is that the composite molecule is selected from at least one of ZSM-5/mordenite, ZSM-5/Y zeolite or ZSM-5/beta zeolite. The SiO ₂ /Al ₂ O ₃ molar ratio of the composite molecular sieve is preferably 10-500, more preferably 20-300. The catalyst carrier is preferably used in an amount of 30-50% by weight of the catalyst weight.

The catalyst preparation method involved in the present invention is as follows: what raw material Mo used was ammonium molybdate or phosphomolybdic acid; what V used was ammonium metavanadate or vanadium pentoxide; what Bi used was bismuth nitrate; what the A type element used was The corresponding nitrates, oxalates, acetates, oxides or soluble halides; the corresponding nitrates, oxalates, acetates, oxides or soluble halides are used for B-type elements; the phosphorus element used Derived from phosphoric acid, triammonium phosphate, diammonium hydrogen phosphate, ammonium dihydrogen phosphate. The molding method of the catalyst is to heat and reflux the slurry added with each component element and carrier on a water bath at 70-80° C. for 5 hours, and then carry out spray drying. The obtained powder is roasted in a muffle furnace at a temperature of 600-750° C. and a roasting time of 3-10 hours.

The present invention adopts a series of transition metals and rare earth metals with low-temperature adsorption, oxidation-reduction properties and bifunctional acid-base coordination, which have strong low-temperature activity and can oxidize and catalyze raw materials. Under the relatively low temperature condition of 600-650°C, the catalyst is used in the catalytic cracking reaction of naphtha, and the yield of ethylene propylene obtained can reach 45%, and a good technical effect has been achieved.

In order to evaluate the activity of the catalyst involved in the present invention, naphtha of C ₄ -C ₁₀ hydrocarbons produced by Shanghai Gaoqiao Petrochemical Company was used as the raw material, and the physical properties of the naphtha are shown in Table 1. A fluidized bed reactor with an inner diameter of 39 mm was used for evaluation. The range of reaction temperature is 600-650°C, the weight space velocity is 0.5-2 hours ^-1 , the weight ratio of water/raw oil is 2-3:1, and the reaction pressure is 0-0.2 MPa.

Table 1 Naphtha Raw Material Indicators

project data Density (20°C) kg/m³ 704.6 Distillation Range Initial Distillation Range °C 40 Final boiling range °C 160 Saturated vapor pressure (20°C) kPa 50.2 Alkanes % (weight %) 65.18 Alkanes contained in alkanes % (weight %) >32.5 Cycloalkane % (weight %) 28.44 Olefin % (wt%) 0.17 Aromatics % (wt%) 6.21

The present invention will be further elaborated below by embodiment.

Detailed ways

【Example 1】

Get 3 grams of ammonium metavanadate, add 100 milliliters of water, drop into 2 milliliters of 80% phosphoric acid, add 3 grams of oxalic acid, heat until the ammonium metavanadate dissolves, and obtain solution (I).

Another 5.89 g of bismuth nitrate was dissolved in 10 ml of 1:1 concentrated nitric acid to obtain a yellow solution. Another 30 grams of ammonium molybdate was dissolved in 200 milliliters of water, poured into the bismuth nitrate solution, and stirred to obtain solution (II).

Take 7.86 grams of cobalt nitrate, 5.58 grams of cerium nitrate, and 6.72 grams of calcium nitrate, and dissolve the three together in 250 milliliters of water to obtain solution (III).

Mix the solutions (I), (II), and (III), heat and stir on a water bath at 70-80°C, add 26 grams of silicon dioxide weighed, reflux for 5 hours, and then dry it with a spray dryer to form. After sieving the obtained powder, place it in a muffle furnace and raise the temperature to 740° C., and burn it for 5 hours. After cooling, the catalyst was sieved again.

The obtained catalyst chemical formula is: Mo _1.0 V _0.15 Co _0.16 Ca _0.17 Ce _0.08 Bi _0.07 O _x +30.6% support

Catalyst activity evaluation was carried out under the following conditions: a fluidized bed reactor with an inner diameter of 39 mm, a reaction temperature of 650° C., and a pressure of 0.02 MPa. The water/naphtha weight ratio is 3:1, the catalyst loading is 20 grams, and the weight space velocity is 1 hour ⁻¹ . The gas products were collected and analyzed by gas chromatography. The product distribution is shown in Table 2.

Table 2 Distribution of main products of pyrolysis and yield of dienes

product Content (weight%) methane 18.32 ethane 3.54 Vinyl 33.47 propane 0.56 Propylene 13.53 C₄ 4.57 Conversion rate 87.5 Ethylene yield (weight%) 31.53 Propylene yield (weight%) 12.96 Ethylene+propylene yield (weight%) 44.49

[Example 2]

Take 284 grams of sodium metasilicate, dissolve it into solution A with 300 grams of distilled water, take 33.3 grams of aluminum sulfate, and make solution B with 100 grams of distilled water, slowly pour B solution into A solution, stir vigorously, and then add 24.4 grams of B Diamine, after stirring for 30 minutes, adjust the pH value at 11.5 with dilute sulfuric acid, control the molar ratio of the sol: Si: Al: ethylenediamine: H ₂ O = 1: 0.1: 0.4: 40, put the mixed solution into In an autoclave, heat it at 180°C for 40 hours, then take it out and wash it twice, dry it at 120°C for 4 hours, and bake it at 550°C for 3 hours to prepare the composite molecular sieve of ZSM-5 and mordenite. Use ammonium nitrate solution with a concentration of 5%, exchange twice at 70°C, and then roast at 550°C for 3 hours, repeat twice to prepare hydrogen ZSM-5/mordenite composite molecular sieve.

Prepare solution (I) with embodiment 1.

Another 30 g of ammonium molybdate, 7.61 g of iron nitrate, 5.88 g of zinc nitrate, and 5.60 g of cerium nitrate were dissolved in 250 ml of water to obtain solution (II). Dissolve 2.24 g of diammonium hydrogen phosphate in 100 ml of water, pour it into solution (II), pour solution (I) into (II), heat and stir in a water bath at 70-80°C, add the weighed silicon dioxide 15 grams and 21 grams of the above-mentioned hydrogen ZSM-5/mordenite composite molecular sieve with a SiO ₂ /Al ₂ O ₃ molar ratio of 20. Reflux for 5 hours, and then dry and shape with a spray dryer. After sieving the obtained powder, place it in a muffle furnace and raise the temperature to 740° C., and burn it for 5 hours. After cooling, the catalyst was sieved again.

The obtained catalyst chemical formula is: Mo _1.0 V _0.15 Fe _0.11 Zn _0.12 Ce _0.08 P _0.10 O _x +37.8% support

Others are the same as in Example 1, and the product distribution and diene yield obtained are shown in Table 3.

The gas phase product distribution and diene yield of table 3 embodiment 2

product Content (H₂ volume%, the rest weight%) Hydrogen (volume%) 15.06 methane 18.08 ethane 3.45 Vinyl 32.65 propane 0.45 Propylene 15.33 C₄ 6.58 other 16.42 Conversion rate 84.36 Ethylene yield (weight%) 30.91 Propylene yield (weight%) 14.52 Ethylene+propylene yield (weight%) 45.43

[Example 3]

Take 284 grams of sodium metasilicate, dissolve it into solution A with 300 grams of distilled water, take 33.3 grams of aluminum sulfate, and make solution B with 100 grams of distilled water, slowly pour B solution into A solution, stir vigorously, and then add 24.4 grams of B Diamine, after stirring for 30 minutes, adjust the pH value to about 11 with dilute sulfuric acid, add 5 grams of Y zeolite seed crystals, and control the molar ratio of the sol: Si: Al: ethylenediamine: H ₂ O = 1: 0.1: 0.4:40, put the mixed solution into an autoclave, keep it warm at 120°C for 36 hours, then take it out and wash it twice, dry it at 120°C for 4 hours, and roast it at 550°C for 3 hours to prepare a composite molecular sieve of ZSM-5 and Y zeolite . Using 5% ammonium nitrate solution, exchanging twice at 70°C, roasting at 550°C for 3 hours, and repeating twice to prepare hydrogen ZSM-5/Y zeolite composite molecular sieve.

Prepare solution (I) with embodiment 1.

Another 30 g of ammonium molybdate, 7.61 g of iron nitrate, 7.29 g of nickel nitrate, 5.60 g of lanthanum nitrate, and 5.18 g of calcium nitrate were dissolved in 250 ml of water to obtain solution (II). Dissolve 2.24 g of diammonium hydrogen phosphate in 100 ml of water, pour it into solution (II), pour solution (I) into (II), heat and stir in a water bath at 70-80°C, add the weighed silicon dioxide 15 grams and 21 grams of the above-mentioned hydrogen ZSM-5/Y composite molecular sieve with a SiO ₂ /Al ₂ O ₃ molar ratio of 20. Reflux for 5 hours, and then dry and shape with a spray dryer. After sieving the obtained powder, place it in a muffle furnace and raise the temperature to 740° C., and burn it for 5 hours. After cooling, the catalyst was sieved again.

The chemical formula of the catalyst is: Mo _1.0 V _0.15 Fe _0.11 Ni _0.15 Ca _0.13 La _0.08 P _0.10 O _x +35.2% carrier

Others are the same as in Example 1, the product yield obtained is ethylene: 27.88%, propylene: 16.54%, ethylene+propylene: 44.42%.

【Example 4】

Take 284 grams of sodium metasilicate, dissolve it into solution A with 300 grams of distilled water, take 16.7 grams of aluminum sulfate, and make solution B with 100 grams of distilled water, slowly pour B solution into A solution, stir vigorously, and then add 12.2 grams of B Diamine and 29.4 grams of tetraethylammonium hydroxide (the mixed template is denoted as M), after stirring for a period of time, adjust the pH value at 11 with dilute sulfuric acid, and control the molar ratio of the sol: Si: Al: M: H ₂ O=1:0.05:0.4:40, add 2.8 grams of zeolite beta seed crystals, put the mixed solution in an autoclave, keep it at 160°C for 40 hours, then take it out and wash it twice, dry it at 120°C for 4 hours, and bake it at 550°C After 3 hours, the ZSM-5/beta zeolite intergrowth molecular sieve was prepared. Using ammonium nitrate solution with a concentration of 5%, exchanging twice at 70°C, and then roasting at 550°C for 3 hours, after repeating twice, the hydrogen-type ZSM-5/beta zeolite symbiotic molecular sieve was prepared.

Prepare solution (I) with embodiment 1.

Prepare solution (II) with embodiment 1.

Take 7.86 grams of cobalt nitrate, 5.58 grams of cerium nitrate, and 6.76 grams of copper nitrate, and dissolve the three together in 250 milliliters of water to obtain solution (III).

Mix the solutions (I), (II), and (III), heat and stir them on a water bath at 70-80°C, add 11 grams of silicon dioxide weighed and the above-mentioned compound with a molar ratio of SiO ₂ /Al ₂ O ₃ of 20 15 grams of hydrogen-type ZSM-5/beta zeolite composite molecular sieves were refluxed for 5 hours, and then dried with a spray dryer to form. After sieving the obtained powder, place it in a muffle furnace and raise the temperature to 740° C., and burn it for 5 hours. After cooling, the catalyst was sieved again.

The obtained catalyst chemical formula is: Mo _1.0 V _0.15 Co _0.16 Cu _0.17 Ce _0.08 Bi _0.07 O _x +30.4% support

Others are the same as in Example 1, the product yield obtained is ethylene: 29.95%, propylene: 14.61%, ethylene+propylene: 44.56%.

【Example 5】

Take 284 grams of sodium metasilicate, dissolve it into solution A with 300 grams of distilled water, take 33.3 grams of aluminum sulfate, and make solution B with 100 grams of distilled water, slowly pour B solution into A solution, stir vigorously, and then add 24.4 grams of B 10 grams of tetraethylammonium hydroxide as diamine, after stirring for 30 minutes, adjust the pH value at about 12 with dilute sulfuric acid, add 5 grams of beta zeolite seed crystals, and control the molar ratio of the sol: Si: Al: ethylenediamine: H ₂ O = 1:0.1:0.4:40, put the mixed solution into an autoclave, heat it at 160°C for 40 hours, then take it out and wash it twice, dry it at 120°C for 4 hours, and bake it at 550°C for 3 hours to obtain mercerized Composite molecular sieve of zeolite and zeolite beta. Using ammonium nitrate solution with a concentration of 5%, exchanging twice at 70°C, and then roasting at 550°C for 3 hours, repeating twice to prepare hydrogen type mordenite/beta zeolite composite molecular sieve.

Prepare solution (I) with embodiment 1.

Another 30 grams of ammonium molybdate, 7.61 grams of iron nitrate, 7.29 grams of nickel nitrate, 5.44 grams of cerium nitrate, and 6.30 grams of copper nitrate were dissolved in 250 milliliters of water to obtain solution (II). Dissolve 2.24 g of diammonium hydrogen phosphate in 100 ml of water, pour it into solution (II), pour solution (I) into (II), heat and stir in a water bath at 70-80°C, add the weighed silicon dioxide 15 grams and 21 grams of the above-mentioned hydrogen-type ZSM-5/beta zeolite composite molecular sieve with a SiO ₂ /Al ₂ O ₃ molar ratio of 20. Reflux for 5 hours, and then dry and shape with a spray dryer. After sieving the obtained powder, place it in a muffle furnace and raise the temperature to 740° C., and burn it for 5 hours. After cooling, the catalyst was sieved again.

The chemical formula of the catalyst is: Mo _1.0 V _0.15 Fe _0.11 Ni _0.15 Cu _0.15 Ce _0.07 P _0.10 O _x +35.2% carrier

Others are the same as in Example 1, the product yield obtained is ethylene: 29.65%, propylene: 12.61%, ethylene+propylene: 42.26%.

[Example 6]

According to the method of Example 2, the hydrogen type ZSM-5/mordenite composite molecular sieve with SiO ₂ /Al ₂ O ₃ molar ratio of 100 was prepared by changing the ratio of raw materials, pH value and the amount of seed crystals added.

Prepare solution (I) with embodiment 1.

Another 30 g of ammonium molybdate, 5.49 g of cobalt nitrate, 5.60 g of zinc nitrate, 5.44 g of cerium nitrate, and 1.10 g of potassium nitrate were dissolved in 250 ml of water to obtain solution (II). Dissolve 2.24 g of diammonium hydrogen phosphate in 100 ml of water, pour it into solution (II), pour solution (I) into (II), heat and stir in a water bath at 70-80°C, add the weighed silicon dioxide 15 grams and 45 grams of the above-mentioned hydrogen ZSM-5/mordenite composite molecular sieve with a SiO ₂ /Al ₂ O ₃ molar ratio of 100. Reflux for 5 hours, and then dry and shape with a spray dryer. After sieving the obtained powder, place it in a muffle furnace and raise the temperature to 740° C., and burn it for 5 hours. After cooling, the catalyst was sieved again.

The obtained catalyst chemical formula is: Mo _1.0 V _0.15 Co _0.11 Zn _0.11 K _0.06 Ce _0.07 P _0.10 O _x +49.1% support

Others are the same as in Example 1, the product yield obtained is ethylene: 36.64%, propylene: 8.50%, ethylene+propylene: 45.14%.

[Example 7]

According to the method of Example 3, the hydrogen type ZSM-5/Y zeolite composite molecular sieve with SiO ₂ /Al ₂ O ₃ molar ratio of 50 was prepared by changing the ratio of raw materials, pH value and the amount of seed crystals added.

Prepare solution (I) with embodiment 1.

Another 30 grams of phosphomolybdic acid, 5.89 grams of bismuth nitrate, 5.49 grams of cobalt nitrate, 5.32 grams of nickel nitrate, 5.44 grams of cerium nitrate, and 10.81 grams of 50% manganese nitrate solution were dissolved in 250 milliliters of water to obtain solution (II). Dissolve 2.24 g of diammonium hydrogen phosphate in 100 ml of water, pour it into solution (II), pour solution (I) into (II), heat and stir in a water bath at 70-80°C, add the weighed silicon dioxide 20 grams and 40 grams of the above-mentioned hydrogen-type ZSM-5/Y composite molecular sieve with a SiO ₂ /Al ₂ O ₃ molar ratio of 50. Reflux for 5 hours, and then dry and shape with a spray dryer. After sieving the obtained powder, place it in a muffle furnace and raise the temperature to 740° C., and burn it for 5 hours. After cooling, the catalyst was sieved again.

The chemical formula of the catalyst is: Mo _1.0 V _0.13 Co _0.1 Ni _0.1 Mn _0.16 Ce _0.07 Bi _0.07 P _0.17 O _x +42% carrier

Others are the same as in Example 1, the product yield obtained is ethylene: 36.10%, propylene: 6.74%, ethylene+propylene: 42.84%.

[Embodiment 8]

According to the method of Example 4, the hydrogen type ZSM-5/beta zeolite composite molecular sieve with SiO ₂ /Al ₂ O ₃ molar ratio of 100 was prepared by changing the ratio of raw materials, pH value and the amount of seed crystals added.

According to the method of Example 7, the mixed solution (I) and the mixed solution (II) containing diammonium hydrogen phosphate were prepared, heated and stirred on a 70-80°C water bath, added and heated and stirred on a 70-80°C water bath, and added Weighed 30 grams of silicon dioxide and 35 grams of the above-mentioned hydrogen-type ZSM-5/beta zeolite composite molecular sieve with a SiO ₂ /Al ₂ O ₃ molar ratio of 100, refluxed for 5 hours, and dried with a spray dryer to shape. After sieving the obtained powder, place it in a muffle furnace and raise the temperature to 740° C., and burn it for 5 hours. After cooling, the catalyst was sieved again.

The obtained catalyst chemical formula is: Mo _1.0 V _0.13 Co _0.1 Ni _0.1 Mn _0.16 Ce _0.07 Bi _0.07 P _0.17 O _x +46.9% carrier

Others are the same as in Example 1, the product yield obtained is ethylene: 36.10%, propylene: 6.74%, ethylene+propylene: 42.84%.

[Example 9]

According to the method of Example 2, the hydrogen type ZSM-5/mordenite composite molecular sieve with SiO ₂ /Al ₂ O ₃ molar ratio of 50 was prepared by changing the ratio of raw materials, pH value and the amount of seed crystals added.

Prepare solution (I) with embodiment 1.

Another 30 g of ammonium molybdate, 7.61 g of iron nitrate, 4.69 g of silver nitrate, 0.95 g of sodium nitrate, and 5.60 g of lanthanum nitrate were dissolved in 250 ml of water to obtain solution (II). Dissolve 2.24 g of diammonium hydrogen phosphate in 100 ml of water, pour it into solution (II), pour solution (I) into (II), heat and stir in a water bath at 70-80°C, add the weighed silicon dioxide 25 grams and 55 grams of the above-mentioned hydrogen ZSM-5/mordenite composite molecular sieve with a SiO ₂ /Al ₂ O ₃ molar ratio of 50. Reflux for 5 hours, and then dry and shape with a spray dryer. After sieving the obtained powder, place it in a muffle furnace and raise the temperature to 740° C., and burn it for 5 hours. After cooling, the catalyst was sieved again.

The obtained catalyst chemical formula is: Mo _1.0 V _0.15 Fe _0.11 Ag _0.17 Na _0.06 La _0.08 P _0.10 O _x +56.3% support

Others are the same as in Example 1, the product yield obtained is ethylene: 37.15%, propylene: 7.82%, ethylene+propylene: 44.97%.

【Example 10】

According to the method of Example 3, the hydrogen type ZSM-5/Y zeolite composite molecular sieve with SiO ₂ /Al ₂ O ₃ molar ratio of 100 was prepared by changing the ratio of raw materials, pH value and the amount of seed crystals added.

Prepare solution (I) with embodiment 1.

Another 30 g of ammonium molybdate, 7.86 g of cobalt nitrate, 6.30 g of copper nitrate, 0.75 g of lithium nitrate, 7.30 g of magnesium nitrate, and 5.60 g of lanthanum nitrate were dissolved in 250 ml of water to obtain solution (II). Dissolve 2.24 g of diammonium hydrogen phosphate in 100 ml of water, pour it into solution (II), pour solution (I) into (II), heat and stir in a water bath at 70-80°C, add the weighed silicon dioxide 20 grams and 45 grams of the above-mentioned hydrogen ZSM-5/mordenite composite molecular sieve with a SiO ₂ /Al ₂ O ₃ molar ratio of 50. Reflux for 5 hours, and then dry and shape with a spray dryer. After sieving the obtained powder, place it in a muffle furnace and raise the temperature to 740° C., and burn it for 5 hours. After cooling, the catalyst was sieved again.

The chemical formula of the catalyst obtained is: Mo _1.0 V _0.15 Co _0.11 Cu _0.16 Li _0.06 Mg _0.17 La _0.08 P _0.10 O _x +51.1% The carrier is the same as Example 1, and the product yield obtained is ethylene: 36.64%, propylene: 8.50%, Ethylene+propylene: 45.14%.

[Example 11]

According to the method of Example 4, the hydrogen type ZSM-5/beta zeolite composite molecular sieve with SiO ₂ /Al ₂ O ₃ molar ratio of 50 was prepared by changing the ratio of raw materials, pH value and the amount of seed crystals added.

Prepare solution (I) with embodiment 1.

Another 30 g of ammonium molybdate, 7.29 g of nickel nitrate, 6.30 g of copper nitrate, 3.40 g of chromium nitrate, 7.55 g of barium nitrate, and 5.60 g of cerium nitrate were dissolved in 250 ml of water to obtain solution (II). Dissolve 2.24 g of diammonium hydrogen phosphate in 100 ml of water, pour it into solution (II), pour solution (I) into (II), heat and stir in a water bath at 70-80°C, add the weighed silicon dioxide 25 grams and 55 grams of the above-mentioned hydrogen-type ZSM-5/beta zeolite composite molecular sieve with a SiO ₂ /Al ₂ O ₃ molar ratio of 50. Reflux for 5 hours, and then dry and shape with a spray dryer. After sieving the obtained powder, place it in a muffle furnace and raise the temperature to 740° C., and burn it for 5 hours. After cooling, the catalyst was sieved again.

The obtained catalyst chemical formula is: Mo _1.0 V _0.15 Ni _0.15 Cu _0.17 Cr _0.05 Ba _0.17 Ce _0.08 P _0.10 O _x +56.3% support

Others are the same as in Example 1, the product yield obtained is ethylene: 37.15%, propylene: 7.82%, ethylene+propylene: 44.97%.

[Example 12]

According to the method of Example 2, the hydrogen type ZSM-5/mordenite composite molecular sieve with SiO ₂ /Al ₂ O ₃ molar ratio of 40 was prepared by changing the ratio of raw materials, pH value and the amount of seed crystals added.

According to the method of Example 3, the hydrogen type ZSM-5/Y zeolite composite molecular sieve with SiO ₂ /Al ₂ O ₃ molar ratio of 40 was prepared by changing the ratio of raw materials, pH value and the amount of seed crystals added.

The mixed solution (I) and the mixed solution (II) containing diammonium hydrogen phosphate were prepared according to the method of Example 7, heated and stirred on a water bath at 70-80°C, and 20 grams of silicon dioxide, SiO ₂ / 20 grams of the above-mentioned hydrogen-type ZSM-5/mordenite composite molecular sieve with an Al 2 O 3 molar ratio of 40 and 20 grams of the above _- mentioned hydrogen _- type ZSM-5/Y zeolite composite molecular sieve with a SiO ₂ /Al ₂ O ₃ molar ratio of 40. Reflux for 5 hours, and then dry and shape with a spray dryer. After sieving the obtained powder, place it in a muffle furnace and raise the temperature to 740° C., and burn it for 5 hours. After cooling, the catalyst was sieved again.

The obtained catalyst chemical formula is: Mo _1.0 V _0.13 Co _0.1 Ni _0.1 Mn _0.16 Ce _0.07 Bi _0.07 P _0.17 O _x +42.1% carrier

The evaluation conditions were the same as in Example 1. Among the obtained products, the yield of ethylene was 36.48%, the yield of propylene was 7.81%, and the total yield of dienes of ethylene and propylene was 44.29%.

[Example 13]

According to the method of Example 2, the hydrogen type ZSM-5/mordenite composite molecular sieve with SiO ₂ /Al ₂ O ₃ molar ratio of 30 was prepared by changing the ratio of raw materials, pH value and the amount of seed crystals added.

According to the method of Example 4, a hydrogen type ZSM-5/beta zeolite composite molecular sieve with a SiO ₂ /Al ₂ O ₃ molar ratio of 20 was prepared by changing the raw material ratio, pH value and the amount of seed crystals added.

According to the method of Example 7, the mixed solution (I) and the mixed solution (II) containing diammonium hydrogen phosphate were prepared, heated and stirred on a 70-80°C water bath, added and heated and stirred on a 70-80°C water bath, and added 10 grams of silicon dioxide weighed, 20 grams of the above-mentioned hydrogen-form ZSM-5/mordenite composite molecular sieve with a SiO ₂ /Al ₂ O ₃ molar ratio of 30, and the above-mentioned hydrogen-form ZSM-5/mordenite composite molecular sieve with a SiO ₂ /Al ₂ O ₃ molar ratio of 20 ZSM-5/beta zeolite composite molecular sieve 20 grams. Reflux for 5 hours, and then dry and shape with a spray dryer. After sieving the obtained powder, place it in a muffle furnace and raise the temperature to 740° C., and burn it for 5 hours. After cooling, the catalyst was sieved again.

The obtained catalyst chemical formula is: Mo _1.0 V _0.13 Co _0.1 Ni _0.1 Mn _0.16 Ce _0.07 Bi _0.07 P _0.17 O _x +37.6% carrier

The evaluation conditions were the same as those in Example 1. Among the obtained products, the yield of ethylene was 36.25%, the yield of propylene was 8.30%, and the total yield of dienes of ethylene and propylene was 44.55%.

[Example 14]

According to the method of Example 3, the hydrogen type ZSM-5/Y zeolite composite molecular sieve with a SiO ₂ /Al ₂ O ₃ molar ratio of 30 was prepared by changing the raw material ratio, pH value and the amount of seed crystals added.

According to the method of Example 4, a hydrogen type ZSM-5/beta zeolite composite molecular sieve with a SiO ₂ /Al ₂ O ₃ molar ratio of 30 was prepared by changing the raw material ratio, pH value and the amount of seed crystals added.

The mixed solution is obtained by the method of Example 1, adding 10 grams of silicon dioxide weighed, SiO ₂ /Al ₂ O The molar ratio of ₃₀ is 20 grams of the above-mentioned hydrogen ZSM-5/Y zeolite composite molecular sieve and SiO ₂ / 30 grams of the above-mentioned hydrogen-type ZSM-5/beta zeolite composite molecular sieve with an _Al2O3 molar ratio of 30 is used as a carrier, and the chemical formula obtained in the same way is: _{Mo 1.0 V 0.15} Co _0.16 Ca _0.17 Ce _0.08 Bi _0.07 O _x +50.4 % supported catalyst. Evaluation by the method of Example 1, in the obtained product, the yield of ethylene was 37.17%, the yield of propylene was 8.25%, and the total yield of dienes of ethylene and propylene was 45.42%.

[Example 15]

Prepare the mixed solution by the method of Example 1, add 500 grams of distilled water for dilution, add 60 grams of SiO ₂ /Al ₂ O ₃ mol ratio is the ZSM-5/mordenite composite molecular sieve of 20 hydrogen type, add 100 grams of SiO ₂ /Al ₂ O ₃ molar ratio of 200 hydrogen type ZSM-5/Y zeolite composite molecular sieve, add 40 grams of SiO ₂ /Al ₂ O ₃ molar ratio of 30 ZSM-5/β zeolite composite molecular sieve, add 22 grams of silicon dioxide According to the same method as in Example 1, a catalyst with the chemical formula of Mo _1.0 V _0.15 Co _0.16 Ca _0.17 Ce _0.08 Bi _0.07 O _x +79.2% carrier was prepared. Evaluation by the method of Example 1, the yield of ethylene was 14.35%, the yield of propylene was 31.09%, and the total yield of ethylene and propylene was 45.44%.

[Examples 16-19]

According to the catalyst prepared in Example 3, the reaction pressure is 0.02MPa, the reaction weight space velocity is 1 hour ⁻¹ , the water/naphtha weight ratio is 3: 1, and the reaction temperature is respectively 550° C.; 580° C.; 670° C. The evaluation was carried out under the conditions of ℃ and 700℃, and the results are shown in Table 4.

[Example 20-24]

According to the catalyst prepared in Example 4, the reaction temperature is 650°C, the reaction weight space velocity is 1 hour ⁻¹ , the water/naphtha weight ratio is 3: 1, and the reaction pressures are respectively 0.5MPa; 0.2MPa; 0.05 MPa; 0.03MPa and 0.01MPa were evaluated, and the results are shown in Table 4.

[Examples 25-29]

The catalyzer that makes by embodiment 6 is 650 ℃ at reaction temperature, and reaction pressure is 0.02MPa, and water/naphtha weight ratio is 3: 1, and reaction weight space velocity is respectively successively 4 hours ^-1 ; 2 hours ^-1 ; 1.2 hours ^-1 ; 0.5 hours ^-1 and 0.1 hours ^-1 under the conditions of evaluation, the results are shown in Table 4.

[Examples 30-33]

According to the catalyst prepared in Example 12, the reaction temperature is 650° C., the reaction pressure is 0.02 MPa, the reaction weight space velocity is 1 hour ⁻¹ , and the water/naphtha weight ratios are respectively 4: 1; 3.5: 1; The evaluation was carried out under the conditions of 2:1 and 1:1, and the results are shown in Table 4.

Table 4

Example Ethylene yield (weight%) Propylene yield (weight%) Ethylene+propylene yield (weight%) Example 16 25.43 15.85 41.28 Example 17 26.68 16.36 43.04 Example 18 29.05 16.22 45.27 Example 19 30.48 14.59 45.07 Example 20 28.05 12.15 40.20 Example 21 28.45 12.89 41.34 Example 22 28.68 13.65 42.33 Example 23 29.05 14.88 43.93 Example 24 30.36 14.92 45.28 Example 25 38.45 6.58 45.03 Example 26 37.84 7.15 44.99 Example 27 37.16 7.68 44.84 Example 28 36.25 8.34 44.59 Example 29 35.88 7.85 43.73 Example 30 38.45 6.84 45.29 Example 31 37.64 6.72 44.36 Example 32 36.05 7.52 43.57 Example 33 35.69 7.17 42.86

Claims (8)

1, the method for a kind of fluid catalytic cracking system ethene and propylene is C with the component ₄～C ₁₀The petroleum naphtha of hydrocarbon is a raw material, is 550～700 ℃ in temperature of reaction, and reaction pressure is 0.001～0.5MPa, and weight space velocity is 0.1～4 hour ^-1, water/petroleum naphtha weight ratio is under 0.5～4: 1 the condition, carries out catalytic cracking reaction and generates ethylene, propylene, wherein said catalyzer is to be selected from SiO ₂Or at least a in the composite molecular screen be carrier, contains with the following composition of atomic ratio measuring chemical formula:

Mo _1.0V _aA _bB _cC _dO _x

A is selected from least a element in period of element Table VIII family, IB family, IIB family, VIIB family, group vib, IA family or the IIA family in the formula;

B is selected from least a in the rare earth element;

C is selected from least a among Bi or the P;

The span of a is 0.01～0.5;

The span of b is 0.01～0.5;

The span of c is 0.01～0.5;

The span of d is 0.01～0.5;

X satisfies the required Sauerstoffatom sum of each element valence in the catalyzer;

Composite molecular screen is to be selected from the mixture that at least two kinds of molecular sieve syntrophism in ZSM-5, Y, β or the mordenite become;

Wherein the support of the catalyst consumption is 20～80% of catalyst weight by weight percentage; VIII family element is selected from least a among Fe, Co or the Ni; IB family element is selected from least a among Cu or the Ag; IIB family element is selected from Zn; VIIB family element is selected from least a among Mn or the Re; The group vib element is selected from least a among Cr, Mo or the W; IA family element is selected from least a among Li, Na or the K; The IIA element is selected from least a among Ca, Mg, Sr or the Ba; Rare earth element is selected from least a among La or the Ce.

2, according to the method for described fluid catalytic cracking system ethene of claim 1 and propylene, the span that it is characterized in that a is 0.01～0.3; The span of b is 0.01～0.3; The span of c is 0.01～0.3; The span of d is 0.01～0.3.

3,, it is characterized in that composite molecular screen described in the support of the catalyst is selected from least a in ZSM-5/ mordenite, ZSM-5/Y zeolite or the ZSM-5/ β zeolite according to the method for described fluid catalytic cracking system ethene of claim 1 and propylene.

4,, it is characterized in that the silica alumina ratio SiO of described composite molecular screen according to the method for described fluid catalytic cracking system ethene of claim 3 and propylene ₂/ Al ₂O ₃Be 10～500.

5,, it is characterized in that the silica alumina ratio SiO of described composite molecular screen according to the method for described fluid catalytic cracking system ethene of claim 4 and propylene ₂/ Al ₂O ₃Be 20～300.

6,, it is characterized in that the support of the catalyst consumption is 30～50% of catalyst weight by weight percentage according to the method for described fluid catalytic cracking system ethene of claim 1 and propylene.

7,, when it is characterized in that containing Cr in the catalyzer composition, be 1: 0.01～0.5 with atomic ratio measuring Mo: Cr according to the method for described fluid catalytic cracking system ethene of claim 1 and propylene.

8,, it is characterized in that temperature of reaction is 600～650 ℃ according to the method for described fluid catalytic cracking system ethene of claim 1 and propylene; Reaction pressure is 0.02～0.2MPa; The reaction weight space velocity is 0.5～2 hour ^-1Water/petroleum naphtha weight ratio is 2～3: 1.