CN101745416B - Catalytic cracking catalyst and preparation method thereof - Google Patents

Abstract

The invention provides a catalytic cracking catalyst and a preparation method thereof. The preparation method of the catalyst comprises the steps of beating silica sol, zeolite and clay-containing matrix, spray-drying the obtained product, allowing the obtained product to be in contact with ammonium salt at a pH between 9 and 11 for first washing exchange and calcination and allowing the obtained product to be in contact with the ammonium salt for second washing exchange. The method can increase the pore volume of the catalyst prepared. The catalyst is used for the catalytic cracking of hydrocarbon oil and can raise conversion rate, gasoline yield and the octane number of gasoline.

Description

A kind of catalytic cracking catalyst and preparation method thereof

Technical field

The present invention relates to a kind of hydrocarbon oil catalytic cracking Catalysts and its preparation method.

Background technology

In catalytic cracking process; For satisfying different demands, obtain maximum economic benefit, adopt different catalyst to different raw materials usually; Yet; Along with crude oil heaviness and poor qualityization day by day, the import that processing heavy oil, residual oil and content of beary metal are high more of catalytic cracking needs is oily, and this is to the anti-carbon deposit demands for higher performance of Cracking catalyst.Because the Silicon-rich substrate catalyst has the gasoline selective height and coking yield is low, therefore utilizes silica-based Cracking catalyst processing heavy oil to come into one's own gradually.

U.S. Pat P3867308 has disclosed by sodium metasilicate and inorganic acid reaction and has prepared acidic silicasol; And then be the method for adhesive preparation catalytic cracking catalyst with the Ludox; Among this preparation method, catalyzer with water is washed, then exchanged rare earth; But prepared catalyst pore volume is little, is unfavorable for the catalytic cracking of heavy oil.

The mixed solution that U.S. Pat P3957689 has disclosed with sulfuric acid and aluminum sulfate prepares Ludox, and then prepares catalyst with prepared Ludox.But there is the little problem of pore volume equally in prepared catalyst.

The Ludox that U.S. Pat P3972835 has introduced dilution obtains low sodium Ludox through storng-acid cation exchange resin, and recycle silicon colloidal sol prepares the method for catalyst.The low sodium Ludox of this method preparation need be through ion-exchange, and the preparation process is complicated, and cost is higher.

U.S. Pat P5961817 discloses the method that the Ludox that utilizes two kinds of different preparation methods to obtain prepares catalyst with USP6022471; This method will be processed slurries by Ludox and clay, the molecular sieve of ion-exchange preparation earlier; To mix with molecular sieve-kaolin-Ludox slurries by the acidic silicasol of sodium metasilicate, sulfuric acid, aluminum sulfate preparation again; Earlier with deionized water and ammonium salt washing, use 50 ℃ of hot washes again behind the drying and moulding.

CN1552801A discloses a kind of catalytic cracking catalyst that contains silica sol binder and preparation method thereof; This preparation method adopts compound binding agent matrix that silica sol binder matrix or Ludox combine with part peptization boehmite and molecular sieve, clay making beating, spray-drying then, prepares with the method for sulphur ammonium washing.

CN1749364A discloses a kind of Cracking catalyst of using silicon bonding; This catalyst is the method that adopts colloidal sol and gel phase to combine; Before shaping of catalyst, keep slurries to be in dissolved colloidal state; Generate the microspheroidal gel through control spray-drying exhaust temperature, the reaming of wearing out again processing obtains.Aging reaming wherein handle be with the microspheroidal gel at 60～90 ℃, pH value is aging more than 0.5 hour in 4.0～6.0 the deionized water, and the microspheroidal gel after aging is washed in deionized water or ammonium sulfate solution, filters, and gets finished product after the drying.Microspheroidal gel after perhaps will wearing out stirs in containing aluminum water solution after in deionized water or ammonium sulfate solution, washing, and control pH value is 4.0～9.0, filters, must finished product after the drying.

Summary of the invention

The technical problem that the present invention will solve provides a kind of preparation method of silica-base catalyst, and this method can improve the pore volume of prepared catalyst.

The present invention provides a kind of preparation method of catalytic cracking catalyst, comprises the steps:

(1) Ludox is mixed with molecular sieve, clay, making beating, spray-drying makes the catalyst microballoon then.

(2) catalyst microballoon that step (1) is obtained and inorganic ammonium salt, H ₂O is according to catalyst: inorganic ammonium salt: H ₂O=1: (0.5～2): the weight ratio of (5～30) is mixed, and regulating its pH value is 9～11, stirs 30～120 minutes down in 50～95 ℃, then washing, drying;

(3) with the dried catalyst microballoon of step (2) 480～650 ℃ of following roastings 2～4 hours;

(4) according to catalyst: inorganic ammonium salt: H ₂O=1: (0.5～2): the catalyst of the weight ratio of (5～30) after with step (3) roasting mixes with inorganic ammonium salt, stirs 20～80 minutes in 60～95 ℃, then washing, drying.

The present invention also provides a kind of catalyst, and this catalyst is prepared by method for preparing catalyst provided by the invention.

The present invention further provides a kind of catalyst cracking method, is included in the step that under the condition of catalytic cracking hydrocarbon ils is contacted with catalyst, it is characterized in that said catalyst is a catalyst provided by the invention.

Compare with the existing method for preparing catalyst with Ludox, the catalyst of method for preparing catalyst preparation of the present invention has higher pore volume, and specific surface area of catalyst increases, and contains more big mesopore in the catalyst, and the heap of catalyst is than reducing; Needn't worry the low saboteur's sieve of pH value of slurries in the washing exchange process, practice thrift the consumption of acid, and the sodium oxide content in the catalyst meet the demands.The heavy oil cracking ability of catalyst of the present invention strengthens, and is used for RFCC, and conversion ratio improves, and gasoline yield is high, and can keep coke selectivity preferably, is the octane number that can improve gasoline unexpectedly.Particularly according to the catalyst of the inventive method with the same composition of alkaline silica sol preparation; Has higher pore volume; Under same condition, carry out cracking reaction; Have higher conversion ratio and the yield of gasoline of Geng Gao, and preparation the time can utilize directly the NaY molecular sieve to prepare catalyst, and not influence the washing exchange of sodium ion in the catalyst.For example, consist of 45 weight % kaolin, 30 weight % molecular sieves, 25 weight %SiO according to the inventive method with acidic silicasol preparation ₂The catalyst of binding agent, its pore volume are 0.39/ml.g ^-1, specific area is 291m ².g ^-1, heap is than being 0.66g.ml ^-1, and according to the Cracking catalyst of the same composition of existing method preparation, its pore volume is 0.35/ml.g ^-1, specific area is 276m ².g ^-1, heap is than being 0.68g.ml ^-1With the decompressed wax oil is that raw material is 7 at oil ratio, and reaction temperature is under 500 ℃ of conditions the invention described above catalyst to be used for catalytic cracking reaction, and gasoline yield is 49.6 weight %; Conversion ratio is 67.1 weight %; Octane number is 90.5, and the above-mentioned catalyst for preparing according to existing method carries out catalytic cracking reaction under similarity condition, and gasoline yield is 47.7 weight %; Conversion ratio is 64.7 weight %, and octane number is 89.7.

The specific embodiment

Among the preparation method provided by the invention; The catalyst microballoon keeps in touch a period of time with after inorganic ammonium salt, water mix in step (2) and the step (4), washs exchange; In step (2), carry out the washing exchange first time, carry out the washing exchange second time in the step (4).Catalyst in the step (2): inorganic ammonium salt: H ₂The weight ratio of O is preferably 1: (0.8～1.6): (8～25), the time of mixing the back stirring is preferably 30～80 minutes, and the temperature of exchange washing is preferably 60～90 ℃, more preferably 70～90 ℃; Catalyst in the step (4): inorganic ammonium salt: H ₂The weight ratio of O is preferably 1: (0.8～1.6): (8～25), the time of mixing the back stirring is preferably 30～80 minutes, and the temperature of exchange washing is preferably 60～90 ℃, more preferably 70～90 ℃.Said ammonium salt can be one or more in ammonium sulfate, ammonium chloride, ammonium nitrate, ammonium phosphate, ammonium hydrogen phosphate or the ammonium dihydrogen phosphate (ADP).In step (2) and (4) with the catalyst microballoon with after ammonium salt solution (mother liquor) contacts a period of time; The catalyst microballoon is separated (for example filtering) with mother liquor; With catalyst detergent, said washing is a prior art then, for example filter cake is washed with 5～15 times of deionized waters to catalyst weight.After in the step (2) catalyst, ammonium salt and water being mixed, under stirring condition, keep a period of time, and according to the situation of change of pH, using ammoniacal liquor, ammonium salt or acid to regulate its pH value is 9～11, said acid is hydrochloric acid, sulfuric acid or nitric acid for example.

Among the preparation method provided by the invention, the sintering temperature in the step (3) is preferably 520～600 ℃.

Among the preparation method provided by the invention, the described Ludox of step (1) is preferably alkaline silica sol, and the pH value of said alkaline silica sol is 10～11.5, SiO in the Ludox ₂Content be 3～20 weight %.Said alkaline colloidal sol contacts with inorganic acid through the waterglass that with modulus is 2.6～3.5, silica concentration is 3～21 weight % and obtains, and the consumption of wherein controlling waterglass and acid makes and contacts the mixture that obtains is that the pH value of Ludox is 10～11.5; The concentration of wherein said waterglass is preferably 5～20 weight %; The consumption of acid makes the pH value of Ludox be preferably 10.2～11.3, and more preferably 10.8～11.2; SiO in the Ludox ₂Concentration be preferably 5～20 weight %, 5～15 weight % more preferably.Said acid is selected from one or more in the inorganic acid commonly used, one or more in hydrochloric acid, sulfuric acid, nitric acid and the phosphoric acid for example, and the concentration of acid is 1～50 weight %, is preferably 5～30 weight %.

In the method for preparing catalyst provided by the invention; When using alkaline silica sol; Waterglass is contacted the alkaline silica sol that obtains in 0～60 ℃ temperature range, have stability preferably with acid; Can be under higher temperature stable existence, thereby can at room temperature prepare Ludox, preferred water glass is 0～45 ℃ with the temperature that acid contacts the Ludox that obtains.The present invention prepares alkaline silica sol, and preparation technology is simple, compares with the preparation acidic silicasol, can practice thrift the consumption of acid, and prepare Ludox with lower-cost waterglass and inorganic acid reaction, thereby can reduce cost, and reduces the pollution to environment; It is stable that prepared Ludox can keep in wider temperature range; And after being mixed with slurries with other component; It is little that the pH value changes, do not pay particular attention to and frequent pH value of regulating slurries, and or not strictness so to the pH value requirement of other component; Prepared slurries stability is high by the slurries stability that acidic silicasol and matrix, active component are mixed with, and is not easy gelling more.Compare with the catalyst that with the acidic silicasol is adhesive preparation, have bigger pore volume and lower bulk density, help the macromolecular cracking reaction of heavy oil.

In the method for preparing catalyst provided by the invention, the said clay of step (1) is to comprise the natural aluminium silicate clay of kaolin, galapectite, bentonite, imvite, sepiolite or a kind of, two or more the mixture in their artificial products made from extra care.

Although any molecular sieve that is applicable to catalytic cracking of hydrocarbon such as faujasite, ZSM-5 zeolite, β zeolite a kind of and their mixture all can be used for the present invention; But find that the preferred zeolite kind is X and y-type zeolite; More preferably y-type zeolite, for example a kind of, two or more the mixture among NaY, HY, REY, REHY, USY, REUSY, DASY, the REDASY.REY, REHY, REUSY and REDASY middle rare earth content are with RE ₂O ₃Count 0.5～20 weight %.

In the method for preparing catalyst provided by the invention; In the step (1) with in Ludox and molecular sieve, the clay pulping process; Also can introduce alumina host; Said alumina host is preferably one or more in hydrated alumina, the hydrated alumina with a diaspore structure with structure of similar to thin diaspore, the hydrated alumina with gibbsite structure, the hydrated alumina with bayerite structure, gama-alumina, the η-aluminium oxide, more preferably has the hydrated alumina of structure of similar to thin diaspore.Introduce alumina host, prepared catalyst heavy oil cracking activity improves, and coke selectivity is better, is used for RFCC, and gasoline yield improves.When using alkaline silica sol of the present invention, introduce alumina host in the catalyst preparation process, need alumina host not used sour peptization, can simplify the preparation process, reduce consuming.

Among the preparation method provided by the invention, in the step (1), the consumption of Ludox, clay and molecular sieve, making the weight with prepared catalyst is benchmark, contains the clay of molecular sieve, 1～70 weight % of 10～94 weight % in the said catalyst, with SiO ₂The silicon bonding of meter 5～89 weight % preferably contains 10～45 weight % molecular sieves, 10～60 weight % clays, 8～45 weight % silicon bondings; When introducing alumina host, with Al ₂O ₃Meter contains the alumina host that is no more than 40 weight % in the catalyst, and said catalyst more preferably contains the clay of molecular sieve, 20～50 weight % of 20～40 weight %, with SiO ₂The silicon bonding of meter 10～30 weight % and the alumina host of 5～15 weight %.

In the production of cracking catalyst provided by the invention, can also comprise the step of exchanged rare earth.Said exchanged rare earth carries out after step (3), for example can step (4) and catalyst after ammonium salt solution contacts be contacted with earth solution to exchange, and the catalyst elder generation exchanged rare earth that also can step (3) roasting be obtained, and then carry out step (4).Catalyst is contacted the method that exchanges be existing method with earth solution, the present invention does not have specific (special) requirements.

In the catalyst cracking method provided by the present invention; Said catalytic cracking condition is existing catalytic cracking condition commonly used; Said hydrocarbon ils is a heavy oil, for example reduced crude, decompression residuum, vacuum gas oil (VGO), AGO (atmospheric gas oil); Straight run gas oil, propane is light/in heavy deasphalted oil and the coker gas oil one or more.

Embodiment 1

Under 22 ℃ the room temperature, get concentration 25 weight % sulfuric acid solution 3.5kg, (catalyst Shandong branch company produces, and contains SiO with the 7.2kg sodium silicate ₂Concentration 20%, modulus 3.2) mixes with 7.3kg decationized Y sieve water and dilute, stir then in the above-mentioned sulfuric acid weak solution of the slow adding of the sodium silicate that will dilute down, obtain SiO ₂Concentration 8 weight %, the pH value is 1.55 Ludox.

In 3.6kg decationized Y sieve water, add 3.0kg kaolin (China Kaolin Co., Ltd produces, solid content 84 weight %), making beating obtains kaolin slurry.Kaolin slurry is mixed with the Ludox slurries, stir.

In 2.3kg decationized Y sieve water, add 2.0kg USY molecular sieve (catalyst Shandong branch company produces, solid content 84.9%), homogenizer fully disperses, and using the watery hydrochloric acid adjust pH is 3.5.

Molecular sieve pulp is joined in above-mentioned Ludox-kaolin slurry, stir, obtain the pH value and be 2.90 dissolved colloidal state catalyst slurry,, obtain the catalyst microballoon this slurries spray-drying.Catalyst consist of 45 weight % kaolin, 30 weight % molecular sieves, 25 weight %SiO ₂Binding agent.

With catalyst microballoon and ammonium sulfate and deionized water according to catalyst: (NH ₄) ₂SO ₄: H ₂The weight ratio of O=1:0.8:20 is mixed, and stirs, and using ammoniacal liquor to regulate slurry pH value is 9.2, is warming up to 70 ℃, and stirs 60 minutes, filters.Filter cake is with 10 times of deionized water drip washing, oven dry to catalyst weight.

Under 520 ℃, to gained oven dry filter cake roasting 2.5 hours.With catalyst and ammonium sulfate and water according to catalyst: (NH ₄) ₂SO ₄: H ₂The weight ratio of O=1:0.8:20 is mixed, and stirs, and is warming up to 70 ℃, stirs 60 minutes, filters.Filter cake is with 10 times of deionized water drip washing, oven dry to catalyst weight.Obtain catalyst A.Its performance is seen table 1.

Comparative Examples 1

Method according to embodiment 1 prepares the catalyst microballoon.Wherein washing for the first time the pH value of using watery hydrochloric acid to regulate slurries in the exchange process is 3.5, rather than to use its pH value of ammoniacal liquor adjusting be 9.2, and other step, condition are identical.Obtain catalyst DB-1.Its performance is seen table 1.

Table 1 is the pore volume that catalyst A and contrast medium DB-1 water droplet method record, intensity that the fluidisation abrasion method records (abrasion index) and heap ratio.Assay method is referring to " petrochemical industry analytical method " (RIPP test method), volumes such as Yang Cuiding, and Science Press, nineteen ninety publishes.

Table 1

Example number	The catalyst numbering	Specific surface/m 2.g -1	Pore volume/ml.g -1	Heap ratio/g.ml -1	Abrasion index %h -1
						Embodiment 1	A	291	0.39	0.66	2.0
Comparative Examples 1	DB-1	276	0.35	0.68	1.9

Embodiment 2

Under 34 ℃ the room temperature, (catalyst Shandong branch company of China Petrochemical Industry produces, SiO with the 17.7kg sodium silicate ₂Content 8.47 weight %, modulus 3.2) adding concentration is the sulfuric acid solution 1.14kg of 25 weight % in stirring down, obtains SiO ₂Concentration 8 weight %, the Ludox of pH value 10.81.

In 3.8kg decationized Y sieve water, add 3.2kg kaolin (China Kaolin Co., Ltd produces, solid content 84 weight %), making beating makes kaolin slurry.

In 2.5kg decationized Y sieve water, add 2.1kgUSY molecular sieve (catalyst Shandong branch company produces, solid content 84.9%), making beating obtains molecular sieve pulp.

Above-mentioned Ludox, kaolin slurry, molecular sieve pulp are mixed, stir, obtain the pH value and be 10.78 catalyst slurry, with this slurries spray-drying, obtain the catalyst microballoon then.Catalyst consist of 45 weight % kaolin, 30 weight % molecular sieves, 25 weight %SiO ₂Binding agent.

With catalyst microballoon and ammonium nitrate and deionized water according to catalyst: NH ₄NO ₃: H ₂The weight ratio of O=1:1.2:20 is mixed, and stirs, and regulating slurry pH value is 9.8, is warming up to 80 ℃, stirs 50 minutes, filters.Filter cake is with 10 times of deionized water drip washing, oven dry to catalyst weight.

Under 600 ℃, to gained oven dry filter cake roasting 2 hours, then with catalyst and ammonium nitrate and deionized water according to catalyst: NH ₄NO ₃: H ₂The weight ratio of O=1:1.2:20 is mixed, and is warming up to 80 ℃, stirs 50 minutes, filters.Filter cake is with 10 times of deionized water drip washing, oven dry to catalyst weight.Obtain catalyst B.Its performance is seen table 2.

Comparative Examples 2

Method according to embodiment 2 prepares the catalyst microballoon.Be 3.8 washing for the first time the pH value of using watery hydrochloric acid to regulate slurries in the exchange process wherein, rather than regulate its pH value with ammoniacal liquor, other step is identical with condition.Obtain catalyst DB-2.Its performance is seen table 2.

Embodiment 3

Under the room temperature, (catalyst Shandong branch company produces, SiO with the 7.8kg sodium silicate ₂Concentration 15 weight %, modulus 2.8) mix with 10.0kg decationized Y sieve water, under agitation adding concentration then is 15 weight % sulfuric acid 1.7kg, obtains SiO ₂Concentration 6 weight %, the Ludox of pH value 10.3.

In 4.1kg decationized Y sieve water, add 4.2kg imvite (southization Red Hill bentonite Co., Ltd produces, and solid content is 78.6 weight %), making beating obtains montmorillonite slurry.

In 2.6kg decationized Y sieve water, add DASY molecular sieve 1.6kg (catalyst Shandong branch company produces, solid content 91.8%), making beating obtains molecular sieve pulp.

Above-mentioned Ludox, montmorillonite slurry, molecular sieve pulp are mixed, stir, obtain the pH value and be 10.2 dissolved colloidal state catalyst slurry,, obtain the catalyst microballoon this slurries spray-drying.Catalyst consists of 55 weight % imvites, 25 weight % molecular sieves, 20 weight %SiO ₂Binding agent.

With catalyst microballoon and ammonium chloride and deionized water according to catalyst: NH ₄Cl:H ₂The making beating of the weight ratio of O=1:1:15 mixes, and the pH value of regulating slurries is 9.3, is warming up to 70 ℃, stirred 40 minutes, and filtration then, filter cake is with 8 times of deionized water drip washing, oven dry to catalyst weight.

Under 560 ℃, to dried filter cake roasting 3 hours, then with itself and ammonium chloride and deionized water according to catalyst: NH ₄Cl:H ₂The weight ratio mixing and stirring of O=1:1:15 is warming up to 70 ℃, stirs 40 minutes, filters.Filter cake obtains catalyst C with 8 times of deionized water drip washing, oven dry to catalyst weight, and its performance is seen table 2.

Embodiment 4

Under 26 ℃ the room temperature, (catalyst Shandong branch company of China Petrochemical Industry produces, SiO with the 7.2kg sodium silicate ₂Content 20 weight %, modulus 3.2) mix with 6.3kg decationized Y sieve water, adding concentration is the sulfuric acid solution 1.2kg of 20 weight % in stirring down then, obtains SiO ₂Concentration 10 weight %, the Ludox of pH value 10.88.

In 3.6kg decationized Y sieve water, add 3.0kg kaolin (China Kaolin Co., Ltd produces, solid content 84 weight %), making beating obtains kaolin slurry.

In 4.2kg decationized Y sieve water, add DASY molecular sieve 2.8kg (catalyst Shandong branch company produces, solid content 91.8%), making beating obtains molecular sieve pulp.

Above-mentioned Ludox, kaolin slurry, molecular sieve pulp are mixed, stir adding boehmite 2.2kg (Shandong Aluminum Plant produces, solid content 33%) down; Making beating; Obtain the pH value and be 10.86 dissolved colloidal state catalyst slurry,, obtain the catalyst microballoon this slurries spray-drying.Catalyst consists of 35 weight % kaolin, 35 weight % molecular sieves, 20 weight %SiO2 binding agents, 10 weight % alumina hosts.

With catalyst microballoon and ammonium phosphate and water according to catalyst: (NH ₄) ₃PO ₄: H ₂The weight ratio of O=1:1.5:20 is mixed, and stirs, and slurry pH value is 10.1, is warming up to 85 ℃, and washing exchange 60 minutes is filtered.Filter cake is with 15 times of deionized water drip washing, oven dry to catalyst weight.

With dried filter cake 550 ℃ of following roastings 2 hours, then with ammonium phosphate and water according to catalyst: (NH ₄) ₃PO ₄: H ₂The weight ratio of O=1:1.5:20 mixes, and stirs, and is warming up to 85 ℃, stirs 60 minutes, filters.Filter cake is with 10 times of deionized water drip washing, oven dry to catalyst weight.Obtain catalyst D.Its performance is seen table 2.

Embodiment 5

Under 15 ℃ the room temperature, (catalyst Shandong branch company of China Petrochemical Industry produces, SiO to get the 6.4kg sodium silicate ₂Content 28.8 weight %, modulus 3.0) mix with 4.3kg decationized Y sieve water, in stirring the hydrochloric acid solution 1.6kg that adds concentration 10 weight % down, obtain SiO then ₂Concentration 15 weight %, the Ludox of pH value 11.17.

Add 2.5kg halloysite (China Kaolin Co., Ltd produces, solid content 74.0 weight %) at above-mentioned Ludox, making beating makes kaolin slurry.

In 3.6kg decationized Y sieve water, add 3.1kg NaY molecular sieve (catalyst Shandong branch company produces, solid content 78.2%), making beating obtains molecular sieve pulp.

Above-mentioned Ludox, kaolin slurry, molecular sieve pulp are mixed, stir, obtain the pH value and be 11.12 dissolved colloidal state catalyst slurry, with this slurries spray-drying, obtain the catalyst microballoon then.Catalyst consist of 30 weight % kaolin, 40 weight % molecular sieves, 30 weight %SiO ₂Binding agent.

With catalyst microballoon and ammonium sulfate and deionized water according to catalyst: (NH ₄) ₂SO ₄: H ₂The weight ratio of O=1:1.8:25 is mixed, and stirs, and regulating slurry pH value is 10.6, is warming up to 90 ℃, and stirs 60 minutes, filters.Filter cake is with 12 times of deionized water drip washing, oven dry to catalyst weight.

Under 580 ℃, to gained filter cake roasting 2 hours.With catalyst and ammonium sulfate and water according to catalyst: (NH ₄) ₂SO ₄: H ₂The weight ratio of O=1:1.8:20 is mixed, and stirs, and is warming up to 90 ℃, stirs 60 minutes, filters.Filter cake obtains catalyst E with 15 times of deionized water drip washing, oven dry to catalyst weight, and its performance is seen table 2.

Table 2 is BET specific surface, the pore volume that the water droplet method records and the heap of catalyst ratios that embodiment 2～5 and Comparative Examples 2 prepared catalyst record with cryogenic nitrogen absorption.

Table 2

Example number	The catalyst numbering	Sodium oxide molybdena/weight %	Specific surface/m 2.g -1	Apparent bulk density/g.ml -1	Weeper volume/ml.g -1
						Embodiment 2	B	0.30	298	0.53	0.52
Comparative Examples 2	DB-2	0.29	275	0.56	0.47
						Embodiment 3	C	0.27	280	0.55	0.51
Embodiment 4	D	0.33	287	0.48	0.68
						Embodiment 5	E	0.38	309	0.52	0.53

Visible by table 1 and table 2, the catalyst of the inventive method preparation, specific area and pore volume obviously improve.Catalyst by the alkaline silica sol preparation has bigger pore volume and lower bulk density.

Embodiment 7

In order to investigate the reactivity worth of catalyst; Respectively to above-mentioned catalyst A, DB-1, B and DB-2 at 800 ℃, behind the burin-in process 8h, in ACE device (fixed fluidized bed), estimate under 100% water vapor conditions; Employed feedstock oil is decompressed wax oil, and character is seen table 3.The reactivity worth of catalyst is seen table 4.

Table 3

Table 4

Example number	Embodiment 1	Comparative Examples 1	Embodiment 2	Comparative Examples 2
					Catalyst	A	DB-1	B	DB-2
Reaction temperature	500	500	500	500
					Oil ratio, wt/wt	7.03	7.03	7.03	7.03
Gas	13.0	12.2	13.9	13.1
					Coke	4.4	4.8	4.6	5.1
Gasoline	49.6	47.7	51.9	49.9
					Diesel oil	18.9	19.3	17.5	19.1
Heavy oil	14.1	16.0	12.1	12.8
					Conversion ratio, %	67.0	64.7	70.4	68.1
Gasoline RON	90.5	89.7	89.9	88.7

Visible by table 4, the catalyst for preparing with the inventive method has higher conversion ratio and yield of gasoline, and heavy oil cracking ability strengthens, and octane number improves.

Comparative Examples 3

Method according to Comparative Examples 2 prepares catalyst, and different is, wash in the exchange process second time after roasting, and after catalyst, sulphur ammonium and water were mixed, using ammoniacal liquor to regulate its pH value was 9.The pore volume of this catalyst is 0.47.

Embodiment 8

The catalyst that embodiment 5 is obtained mixes with re chloride, catalyst in the mixture: RE ₂O ₃: water (weight ratio)=1:0.2:20, stirred 40 minutes down at 70 ℃, filter then, drying, obtain containing the Cracking catalyst of rare earth.

Claims (13)

1. the preparation method of a catalytic cracking catalyst may further comprise the steps:

(1) Ludox is mixed with molecular sieve, clay, making beating, spray-drying makes the catalyst microballoon then; Said Ludox is SiO ₂Content is that 3～20 weight %, pH value are 10～11.5 alkaline silica sol;

(2) catalyst microballoon that step (1) is obtained and inorganic ammonium salt, H ₂O is according to catalyst: inorganic ammonium salt: H ₂O=1: (0.5～2): the weight ratio of (5～30) is mixed, and regulating its pH value is 9～11, stirs 30～120 minutes down in 50～95 ℃, then washing, drying;

(3) with the dried catalyst microballoon of step (2) 480～650 ℃ of following roastings 2～4 hours;

(4) with the catalyst microballoon after step (3) roasting and inorganic ammonium salt and water according to catalyst: inorganic ammonium salt: H ₂O=1: (0.5～2): the weight ratio of (5～30) is mixed, in 60～95 ℃ of stirrings 20～80 minutes, washing, drying then.

2. according to the described method of claim 1, it is characterized in that catalyst in step (2) and/or the step (4): inorganic ammonium salt: H ₂O=1: (0.8～1.6): (8～25).

3. according to the described method of claim 1, it is characterized in that the temperature of step (2) and/or step (4) is 70～90 ℃.

4. according to the described method of claim 1, it is characterized in that the sintering temperature in the step (3) is 520～600 ℃.

5. according to the described method of claim 1, it is characterized in that described Ludox is an alkaline silica sol, its SiO ₂Content is 3～20 weight %, and the pH value is 10～11.5.

6. according to the described method of claim 5, it is characterized in that the pH value of described Ludox is 10.2～11.3.

7. according to the described method of claim 6, it is characterized in that SiO in the described Ludox ₂Content be 5～15 weight %, the pH value of Ludox is 10.8～11.2.

8. according to the described method of claim 5, it is characterized in that the temperature of Ludox is 0～60 ℃.

9. according to the described method of claim 5, it is characterized in that the preparation method of said Ludox is following: with SiO ₂Content is that 3～21 weight %, modulus are that 2.6～3.5 water glass solutions mix with inorganic acid, and it is 10～11.5 that the consumption of acid makes the pH value of the mixture that obtains.

10. according to the described method of claim 9, it is characterized in that described acid is one or more in hydrochloric acid, sulfuric acid, nitric acid and the phosphoric acid, the concentration of acid is 1～50 weight %.

11. a Cracking catalyst is characterized in that, said catalyst is by preparation method's preparation of each catalytic cracking catalyst that is provided of claim 1～10.

12., it is characterized in that according to the described Cracking catalyst of claim 11, be benchmark with the weight of catalyst, contain the clay of molecular sieve, 1～70 weight % of 10～94 weight % in the said catalyst, with SiO ₂The silicon bonding of meter 5～89 weight %.

13. a catalyst cracking method is included in the step that under the condition of catalytic cracking hydrocarbon ils is contacted with catalyst, it is characterized in that said catalyst is claim 11 or 12 described Cracking catalyst.