CN1020369C - Cracking catalyst containing novel high silicon Y zeolite - Google Patents

Abstract

The invention discloses a fluid catalytic cracking catalyst containing novel high-silicon zeolite, wherein the novel high-silicon zeolite is prepared by alternately treating Y-type zeolite through two processes of chemical dealumination and hydrothermal treatment, and the treatment condition is slower and easier than that of singly using one of the Y-type zeolite in the prior art, and has the advantages of short time, low cost and high flexibility. The product has high crystallinity, low sodium content, good thermal and hydrothermal stability and strong selectivity, and the catalyst prepared by the method is suitable for treating various petroleum hydrocarbons including heavy oil or residual oil, and has better performance than similar comparative catalysts.

Description

The present invention relates to a fluidized catalytic cracking catalyst containing novel high-silicon Y zeolite, a method for obtaining the contained zeolite and using it to prepare the catalyst, and the application of the catalyst in the production of high-octane gasoline by fluidized catalytic cracking hydrocarbon feedstock.

Using fluidized catalytic cracking to process hydrocarbon feedstock to obtain high-yield, high-octane gasoline is an important process in the petroleum refining industry. The key is the performance of the active components of the catalyst, that is, the high-silicon Y zeolite contained in it is required to keep the crystal structure intact , has high thermal and hydrothermal stability, strong acidity and low acid density. In order to obtain the high-silica zeolite with the above-mentioned properties, the artificially synthesized NaY zeolite is usually properly processed to reduce the aluminum content in the original zeolite, reduce the unit cell constant, and increase the silicon-aluminum ratio of the zeolite framework, thereby Reduce acid density, improve thermal stability and hydrothermal stability. The treatment methods for this purpose are in the prior art: hydrothermal dealumination and chemical dealumination. The former is to roast NH ₄ Y zeolite at high temperature in the presence of water vapor to obtain high-silicon Y zeolite, which is called ultra-high silicon Y zeolite. Stabilized Y zeolite (USY) [see US, 3,293,192; 4,036,739]; the latter is the use of fluorosilicates, such as ammonium fluorosilicate or other salts containing fluorine, such as ammonium fluoride, Ammonium fluoroborate is used as a dealumination agent to remove the aluminum in the framework of NH ₄ Y or NaY zeolite, and at the same time move silicon into the vacancy after dealumination in the framework, which is called framework silicon-rich Y zeolite (FSEY) [see US, 4 , 503, 023, (1985); NPRA Annual Meeting 1986, AM-86-30]. Or use ethylenediaminetetraacetic acid as a dealumination agent to prepare a high silica zeolite, called dealuminated Y zeolite, (DAY) [see US, 3,442,795 (1969)]. Because USY reduces the acid density and inhibits the hydrogen transfer reaction, it can produce high-octane gasoline and can be used to process heavy oil. However, during its preparation, the dealumination of the zeolite framework is difficult to match with the speed of silicon migration, which makes the framework dealumination The vacancies generated in the process cannot be occupied by silicon atoms in time, thus affecting the stability of the framework, and even when there are many vacancies, the framework structure will collapse, which will damage the crystallinity and reduce the activity. In addition, the stabilization reaction during the treatment is carried out in the solid phase, and the aluminum released from the framework remains in the cage structure of the zeolite. This non-skeletal aluminum "fragment" will cause non-selective cracking reactions Increase, thereby reducing the yield of gasoline [see Pellet, RJ et al., J.Catal, 114, 71-89 (1988)]. European Patent Publication EP, 82111 (1983) and Chinese Patent Publication CN, 85108330A (1987) disclose a new method for preparing high-silica Y zeolite, and obtain a high-silica zeolite named LZ-210, which is obtained by using fluosilicic acid Ammonium solution treats NH ₄ Y or NaY zeolite, the aluminum on the zeolite framework is complexed by fluorine into the solution, and the silicon in the solution is then transferred to the vacant position left after dealumination, this kind of dealumination and In the silicon-rich process, it is easier to find conditions that match the transfer speeds of aluminum and silicon, so that the prepared LZ-210 zeolite has fewer framework defects, high crystallization retention, and does not contain framework aluminum "fragments". The silicon-aluminum ratio of the skeleton can be adjusted arbitrarily, the sodium content is also low, and its thermal and hydrothermal stability is high. Compared with similar catalysts containing USY, the catalyst prepared from it has higher activity and higher selectivity. Well, it has the ability to resist heavy metal pollution and can be used to treat heavy oil or residual oil.

The above-mentioned USY zeolite production conditions are harsh and the process is complicated. The technology for preparing high-silica zeolite from fluorosilicate also has problems in industrial production, such as strict condition control requirements, long process flow, and high production costs, which limit its wide application. In order to overcome the above-mentioned unfavorable factors, it is necessary to develop a new type of fluidized catalytic cracking catalyst. The present invention provides a method of combining the chemical dealumination process and the hydrothermal treatment process alternately, which can be prepared by using cheaper raw materials under relatively mild operating conditions. Novel high silicon Y zeolite and use it to prepare fluidized catalytic cracking catalyst.

The novel high-silica Y zeolite prepared by the present invention, as shown in formula (I) or JJ), is obtained by combining chemical dealumination process and hydrothermal treatment process and using alternately to process Y-type zeolite; Mixed with base to make fluidized catalytic cracking catalyst, which can be used to treat distillate oil or residual oil.

It is called B method, and the formula (II) method is called C method. The chemical dealumination process involved is that under the action of a complexing agent, the aluminum that is released from the skeleton can also be released from the non-skeleton aluminum. Subsequent hydrothermal treatment is carried out to migrate silicon in the solid phase, so that silicon atoms occupy the vacancies left after dealumination to achieve structural stabilization. This process is also accompanied by a certain degree of hydrothermal dealumination. As mentioned above, the depth of dealumination can be controlled by alternating chemical dealumination and hydrothermal treatment, and a high-silicon Y zeolite with the required silicon-aluminum ratio can be obtained. Because it has the characteristics of both FSEY and USY, it is called a new type of high-silicon Y zeolite. Zeolite Y (NHSY). The number of times that the two processes shown in formula (II) are used alternately depends on the requirements for high silica zeolite.

The dealumination complexing agent used in the chemical dealumination process of the present invention includes: organic acids, such as ethylenediaminetetraacetic acid, oxalic acid, sulfosalicylic acid, etc.; organic alcohol amines, such as triethanolamine, etc.; Organic and inorganic acid salts, such as ammonium oxalate, ammonium fluoride, ammonium fluorosilicate, ammonium fluoroborate, etc.; a mixture of the above complexing agents can also be used, and the same or different complexing agents can be used for each chemical dealumination. mixture. The amount of the complexing agent can be calculated stoichiometrically according to the degree of dealumination of the zeolite, and the degree of pre-dealuminum is determined according to the required silicon-aluminum ratio of the product. The dealumination conditions are based on the principle of ensuring uniform and slow dealumination of the zeolite framework. Generally, 1-20% (weight) complexing agent aqueous solution is used, preferably 5-10% solution; reaction time is 1-6 hours, preferably 2-4 hours; reaction temperature is 25-100°C, preferably 50-95°C . The condition of hydrothermal treatment is milder than that of USY and the time is shorter. The general treatment temperature is 400-700°C, preferably 500-600°C for 1-3 hours; the concentration of water in the atmosphere depends on the required depth of hydrothermal dealumination Depending on the situation, the general atmosphere contains 20-100% water (volume), or the zeolite containing 30-50% water can be vaporized by itself.

）值随产物硅铝比的提高而变小，产物的SiO₂/Al₂O₃比一般控制在6-40，最好在8-20，氧化钠含量小于1.0%，最好小于0.5%，相对结晶度大于80%，最好大于90%。The zeolite raw material used in the present invention is Y-type zeolite, its silicon-aluminum ratio (SiO ₂ /Al ₂ O ₃ ) is greater than 4.0, preferably greater than 4.5, and the obtained high-silica zeolite still has faujasite (Faujusite ) structure characteristic lines, just the interplanar spacing (d

) value becomes smaller with the increase of the silicon-aluminum ratio of the product. The SiO ₂ /Al ₂ O ₃ ratio of the product is generally controlled at 6-40, preferably 8-20, and the sodium oxide content is less than 1.0%, preferably less than 0.5%. The relative crystallinity is greater than 80%, preferably greater than 90%.

The substrate used in the preparation of the catalyst of the present invention is an inorganic oxide, for example, alumina-silica, silica gel or silicon solution, aluminum colloid or activated alumina, natural clay or a mixture thereof can be used. The mixture formed by two or more oxides must have a certain pore structure and catalytic activity. Mix the finely ground active components with the matrix to make a fluidized catalytic cracking catalyst according to a conventional method, which can contain 10-50% (weight) of active components, preferably 15-30%. In the device, it can produce high-octane gasoline by contacting with feedstock oil, including distillate oil or residual oil, under conventional operating conditions.

The main features of the high-silica zeolite obtained in the present invention are: 1. There are few aluminum vacancies in the zeolite framework structure; 2. The distribution of aluminum on the inner and outer surfaces of the zeolite is relatively uniform; 3. Non-framework aluminum "fragments" existing in the cavity of the framework structure "The amount can be controlled arbitrarily; 4. The zeolite has a developed secondary pore structure; 5. The sodium content of the zeolite is low; 6. The silicon-aluminum ratio or unit cell constant of the zeolite framework is easier to control. These characteristics make the zeolite have high thermal stability, hydrothermal stability, catalytic activity and high selectivity, and the fluid catalytic cracking catalyst prepared by using the zeolite has high activity and excellent selectivity. See Table 1-7 and Figure 1-7.

The aluminum vacancies in the zeolite framework structure described in the present invention are characterized by the defect structure factor Z, which can be measured by the method introduced in US Patent No. 4,503,023 (1985), that is, the infrared spectrum of the sample in the hydroxyl region is 3710cm ^- The background absorbance of ¹ ; the silicon-aluminum ratio on the surface of zeolite can be measured by X-ray photoelectron spectroscopy; the aluminum "fragments" in the zeolite framework cavity can be measured by ²⁷ AlMAS-NMR, and the more convenient method is to measure the 3600cm of hydroxyl region by the method of the present invention ^-1 infrared absorption band (as shown in Figure 1); the secondary pore structure of zeolite can be determined by the low-temperature nitrogen adsorption layer thickness method; the zeolite unit cell constant a. It is determined by conventional X-ray diffraction method, using silicon powder as an internal standard, and measuring the diffraction angles near 2θ equal to 54° and 58.3°; the integrity of zeolite crystals is expressed by the crystallinity relative to the starting NaY, that is, the relative crystallinity , the specific method is to measure the sample and starting NaY at (331), (511, 333), (440), (533), (642), (822, 660), (555, 751) by X-ray diffraction method The diffraction peak height at (644) and the half maximum width of (533) peak, according to the following formula to calculate the relative crystallinity (Xi);

Xi＝I _i W _i /I _R W _R

i represents the sample to be tested, R represents the starting NaY, I is the sum of the peak heights of the eight peaks, and W is the half-height width of the (533) peak. All the samples to be tested have been exchanged with sodium chloride solution. (Table 1-Table 7 see the text below)

The following examples are listed in order to illustrate the present invention more clearly, but they do not limit the scope of the present invention in any way.

Example 1

Add 30g (dry basis) NaY (SiO ₂ /Al ₂ O ₃ =5.2) to 300 ml of about 10% ammonium sulfate aqueous solution, stir, and slowly add 150 ml of 10% (weight) oxalic acid and oxalic acid at 95-100°C Ammonium (the ratio of the two is 2:3) mixture aqueous solution, continue to stir for 1 hour after the addition, filter, wash with water, and treat the wet filter cake with water vapor at 600°C for 2 hours. Repeat the above process once more. After weighting, the product was treated once with 2% ammonium fluoride aqueous solution at 95°C at a ratio of 10 ml of solution per gram of solid, filtered and washed with water, and dried at 120°C to obtain a new type of high silica Y zeolite (NHSY-C). The main analysis results are as follows:

Relative crystallization Structure collapse Specific surface

Na₂O%a ₀ ,

Na ₂ O%

Degree % Temperature ℃ m ² /g

24.423 96 0.35 1062 854

Example 2

Add 30g (dry basis) NaY (SiO ₂ /Al ₂ O ₃ =5.2) and 300 ml of about 10% ammonium sulfate aqueous solution and stir, raise the temperature to 95-100°C and slowly add 150 ml of 10% (weight) oxalic acid and oxalic acid Aqueous solution of ammonium mixture, continue to stir for 1 hour after addition, filter, wash with water, treat the wet filter cake with water vapor at 600°C for 2 hours, exchange the product with 300 ml of about 10% ammonium sulfate aqueous solution at 95°C for 1 hour, filter, wash with water, filter cake Add 300 ml of 5% ammonium acetate aqueous solution for beating, raise the temperature to 60-65°C, slowly add 42 ml of 5% ammonium fluorosilicate aqueous solution, after adding, heat up to 90°C and continue stirring for 2 hours, filter, wash with water, according to the product According to the sodium content requirements, the filter cake can be exchanged once with 5-10% ammonium sulfate according to the conventional method, or not. Finally, the filter cake is dried at 120°C to obtain a new type of high-silica Y zeolite (NHSY-B). The main analysis results are as follows:

Relative crystallization Structure collapse Specific surface

Na₂O%a.

Na ₂ O%

Degree % Temperature ℃ m ² /g

24.470 96 0.24 1065 794

Example 3

Add 650g (dry basis) NaY (SiO ₂ /Al ₂ O ₃ =5.3) to 6.5 liters of water, add 650 grams of ammonium sulfate, stir and raise the temperature to 95-100°C, slowly add 3.3 liters of 10% by weight oxalic acid and ammonium oxalate mixture After adding the aqueous solution, continue to stir for 1 hour, filter, wash with water, and bake the filter cake at 600° C. for 2 hours in the presence of water vapor. Repeat the above process once more. After weighting, the product was treated once with 2.5% ammonium fluoride aqueous solution at 95°C at a ratio of 10 ml of solution per gram of solid, filtered, washed with water, and exchanged once with ammonium sulfate aqueous solution according to the conventional method, and finally the filter cake was baked at 120°C Dry to obtain zeolite product (NHSY-C). The main analysis results are as follows:

Structural collapse

Relative Concrete Surface

Na₂O% 塌温度 Za.

Na ₂ O% collapse temperature Z

Crystallinity% ℃ m ² /g

24.415 110 0.08 1083 0.024 867

The fluidized catalytic cracking catalyst is prepared by mixing NHSY-C with the substrate, and the content of NHSY-C in the catalyst is 25% (weight). The preparation process is as follows:

After NHSY-C is ground, it is mixed with water glass (provided SiO ₂ is equivalent to 65% of the weight of the matrix) for beating, and added aluminum sulfate (provided Al ₂ O ₃ is equivalent to 25% of the weight of the matrix) to form a gel, and after aging Add sodium metaaluminate, then age, finally add aluminum sulfate to make the system pH = 3-4, add ammonia water to adjust pH = 5-6, after the gel is homogeneously milled, spray-dried, the obtained microspheres are sieved and then washed with water , remove the salt. The serial number of catalyst is FC, and its analysis result is as follows:

Na ₂ O% Al ₂ O ₃ % SiO ₂ % Specific surface pore volume

m ² /g ml/g

0.16 27.02 72.10 287 0.346

According to the same method as above, mix NHSY-B with the substrate to make a fluidized catalytic cracking catalyst, coded as F-B.

Example 4

For comparison, a fluid catalytic cracking catalyst containing FSEY was prepared as a comparative catalyst. FSEY was first prepared by dealumination of ammonium fluorosilicate.

Take 560 grams of NH ₄ Y (dry basis SiO ₂ /Al ₂ O ₃ =5.3) with an NH ⁺ ₄ exchange degree of 80%, add 6.5 liters of water, add 650 grams of NH ₄ Ac, make a slurry, and raise the temperature to 60-65°C. Slowly add 5280 ml of 5% ammonium fluorosilicate solution into the system, heat up to 80°C after about 4 hours, stir for 2 hours, then heat up to 90°C and stir for 2 hours, filter, wash with hot water, press the filter cake again The conventional method is to exchange four times with ammonium sulfate solution, and after the final filter cake is fully washed with water, it is dried at 120°C to obtain the product FSEY. The main analysis results are as follows:

Structural collapse

Relative Concrete Surface

塌温度 Z Na₂O%a.

Collapse temperature Z Na ₂ O%

Crystallinity% ℃ m ³ /g

24.471 99 1080 0.026 878 0.11

FSEY was mixed with the substrate at a ratio of 25:75 to make a fluidized catalytic cracking catalyst. The preparation procedure was the same as in Example 3, and the catalyst number was F-A. The main analysis results are as follows:

specific surface pore volume

Na ₂ O% Al ₂ O ₃ % SiO ₂ % m ² /g ml/g

0.44 26.90 71.25 403 0.393

Another comparative catalyst used in the present invention is F-O, which is a commercial fluid catalytic cracking catalyst containing USY for the cracking of residual oil to produce high-octane gasoline. The zeolite content in the catalyst is greater than 30% by weight.

Example 5

The evaluation of the catalysts of the present invention and comparative catalysts was carried out on a small fixed fluidized bed unit. Before evaluation, the catalyst was first deactivated under the conditions of 800°C and 100% steam for 10 hours. The operating temperature, weight hourly space velocity (WHSV) and ratio of catalyst to feed oil (C/O) of the evaluation device are listed in the evaluation result table. The properties of the feed oil used in the evaluation are as follows:

Viscosity ν ₁₀₀ 4.65 (centitos) Average molecular weight 331

Carbon residue 0.276 (weight %) Initial boiling point (°C) 252

Specific gravity 0.8524 Distillation 10% (℃) 306

Refractive index 1.4924 Distillation 50% (℃) 400

Flash point 149 (°C) Distillation 90% (°C) 501

Freezing point +36 (°C) Final boiling point (°C) 501

Total distillate %93

The cracking reaction product is expressed as the weight percentage (weight %) of the specific product to the feedstock, including the following hydrogen and hydrocarbons:

H ₂ hydrogen

C ₁ methane

C ₂ ethane and ethylene

C ₃ propane and propylene

C ₄ butane, isobutane and butene

Gasoline boiling point 43-220°C

Diesel boiling point 220-330℃

Heavy oil Zeolite＞330℃

Coke A precursor of coke and/or char that accumulates on a catalyst

Definition: Gasoline yield (weight %) = weight of gasoline / weight of raw materials

Conversion rate (weight%) = (weight of raw material - weight of heavy oil) / weight of raw material

Gasoline selectivity (%) = gasoline (weight %)/conversion (weight %)

Light oil selectivity (%)=[gasoline (weight %)+diesel (weight %)]/conversion rate (weight %)

Coke selectivity (%) = coke (weight %)/conversion

Rate (weight%)

Dry gas selectivity (%) = H ₂ +C ₁ +C ₂ (weight %)/conversion (weight %)

C ₃ +C ₄ hydrocarbon selectivity (%)=C ₃ +C ₄ (weight %)/conversion (weight %)

The evaluation results of catalyst FC of the present invention and FB and comparison catalyst FA and FO are listed in table 4, 5, 6, 7 respectively, according to the data in the table, the gasoline yield of each catalyst under the same reaction conditions and conversion ratio contrast figure ( Figure 2), the relationship between the gasoline selectivity, light oil selectivity, coke selectivity, dry gas selectivity and C ₃ +C ₄ hydrocarbon selectivity of each catalyst and the conversion rate are drawn as shown in Figure 3, 4, 5 , 6, and 7. It can be seen from the data in the table that the octane number levels of the catalyst of the present invention and the comparison catalyst are similar, and the octane number of the chromatographic method is above 91. Figure 2 shows that, compared with the comparison catalyst, the gasoline yield and conversion rate of the catalyst of the present invention are higher. Figure 3 and Figure 4 respectively show that the catalyst of the present invention has higher gasoline selectivity than the comparison catalyst, and the light oil selectivity is also better. Figure 5 shows that the coke selectivity of each catalyst is good and comparable to each other. Figures 6 and 7 show that the gas selectivity of the catalyst FB of the present invention is almost the same as that of the comparison catalyst, and FC is better. The above results show that the catalyst of the present invention has improved activity and selectivity, showing the superiority of the novel high-silica Y zeolites (NHSY-C and NHSY-B) prepared by the method of the present invention.

Brief description of the drawings:

Figure 1 NHSY-C with different Al "fragments" contents

Aluminum "fragments" content a>b>c

Figure 2 Catalyst activity comparison

(1) Gasoline yield on the ordinate, weight %

(2) Conversion rate on the ordinate, weight %

Reaction conditions: Reaction temperature 480°C, WHSV～16.0, C/0～3.0

Figure 3 Relationship between gasoline selectivity and conversion

Figure 4 The relationship between light oil selectivity and conversion

Figure 5 The relationship between coke selectivity and conversion

Figure 6 The relationship between dry gas selectivity and conversion

Fig. 7 Relationship between C ₃ +C ₄ hydrocarbon selectivity and conversion

Table 1 Comparison of the stability of high silica Y zeolites prepared by different methods

Before water vapor treatment After water vapor treatment

Sample preparation method NaO ₂ weight

Xi a. Structural collapse temperature Xi a.

℃ %

% %

℃%

Ammonium Fluosilicate Dealumination 0.65 92 24.45 1086 88 24.28

Method B of the present invention 0.24 97 24.48 1071 92 24.28

Method C of the present invention 0.33 92 24.44 1056 92 24.26

Hydrothermal dealumination - 93 24.45 1002 80 24.19

Note: Water vapor treatment conditions: 100% water vapor at 800°C for 3 hours

Table 2 Comparison of secondary pore structures of high silica Y zeolites prepared by different methods

Surface area m ² /g

微孔体积ml/gSample preparation method a.

Micropore volumeml/g

S _total S _medium S _large

Ammonium Fluosilicate Dealumination 24.45 727 12 27 0.251

Method B of the present invention 24.47 794 53 78 0.244

Method C of the present invention 24.44 854 133 34 0.254

Hydrothermal dealumination 24.52 759 83 7 0.253

）表面积，S_大-大孔（＞200

）表面积＊S _total -total surface area, S _medium -medium pores (40-200

) surface area, S _large - large pores (> 200

) surface area

Table 3 Comparison of surface aluminum distribution of high silica Y zeolites prepared by different methods

Si/Al（Ⅰ）^＊Si/Al（Ⅱ）Sample preparation method a.

Si/Al (I) ^* Si/Al (II)

Ammonium Fluosilicate Dealumination 24.471 5.86 22.0

The method of the present invention 24.415 6.80 11.2

Hydrothermal dealumination 24.482 4.73 1.27

＊Si/Al(I)-silicon-aluminum ratio determined by chemical analysis

Si/Al(II)-Silicon-aluminum ratio determined by X-ray photoelectron spectroscopy

Table 4 Catalyst F-A Evaluation Results

Reaction temperature, ℃ 480 490 500 510

WHSV 16.04 15.90 15.71 16.17

C/O ratio 3.00 3.41 3.77 4.03

H ₂ +C ₁ +C ₂ ,wt% 0.67 0.90 1.10 1.40

C ₃ +C ₄ , weight% 18.2 21.6 23.6 25.6

Gasoline, weight % 46.3 49.7 50.4 50.2

Diesel, wt% 15.9 14.4 13.7 11.4

Heavy oil, wt% 17.5 11.6 9.3 9.1

Coke, wt% 1.5 1.8 2.0 2.2

Conversion rate, weight % 82.5 88.3 90.7 91.1

Octane number (chromatographic method) 91.4 92.2 91.0

Gasoline selectivity, % 56.1 56.3 55.6 55.1

Light isoselectivity, % 75.4 72.04 70.7 67.1

Coke selectivity, % 1.82 2.04 2.21 2.41

Dry gas selectivity, % 0.81 1.02 1.21 1.54

C ₃ +C ₄ selectivity, % 22.1 24.5 26.0 28.1

Table 5 Catalyst F-B evaluation results

Reaction temperature, ℃ 470 480 490 500 510

WHSV 19.86 16.15 15.85 16.01 15.96

C/O ratio 3.01 3.00 3.39 3.74 4.02

H ₂ +C ₁ +C ₂ ,wt% 0.80 1.00 1.20 1.30 1.90

C ₃ +C ₄ ,wt% 18.1 20.0 24.1 25.6 28.7

Gasoline, weight % 51.1 51.9 50.1 50.3 48.8

Diesel, weight% 15.4 14.5 14.2 12.3 12.6

Heavy oil, wt% 12.6 10.4 8.5 8.4 5.3

Coke, wt% 2.0 2.1 2.3 2.2 2.9

Conversion rate, weight % 87.4 89.6 91.5 91.6 94.7

Octane number (chromatographic method) 91.3 91.3 91.6 93.8

Gasoline selectivity, % 58.5 57.9 54.8 54.9 51.5

Light oil selectivity, % 76.1 74.1 70.3 68.3 64.8

Coke selectivity, % 2.29 2.34 2.51 2.40 3.06

Dry gas selectivity, % 0.92 1.12 1.31 1.42 2.01

C ₃ +C ₄ selectivity, % 20.7 22.3 26.32 27.9 30.3

Table 6 Catalyst F-C evaluation results

Reaction temperature, ℃ 470 480 490 500 510

WHSV 21.60 16.08 15.09 15.17 16.35

C/O ratio 2.98 3.00 3.41 3.75 4.07

H ₂ +C ₁ +C ₂ ,wt% 0.8 1.0 1.3 1.5 2.0

C ₃ +C ₄ ,wt% 18.4 20.7 24.4 27.4 29.8

Gasoline, weight % 51.8 53.1 53.1 51.4 48.7

Diesel, weight % 16.2 15.0 11.9 11.2 10.5

Heavy oil, wt% 10.8 7.9 6.8 6.1 6.0

Coke, wt% 2.0 2.2 2.5 2.4 3.1

Conversion rate, weight % 89.2 92.1 93.2 93.9 94.6

Octane number (chromatographic method) 91.6 91.6 92.2

Gasoline selectivity, % 58.1 57.7 57.0 54.7 51.5

Light oil selectivity, % 76.2 73.9 69.7 66.7 62.6

Coke selectivity, % 2.24 2.39 2.68 2.56 3.28

Dry gas selectivity, % 0.90 1.09 1.39 1.60 2.11

C ₃ +C ₄ selectivity, % 20.6 22.5 26.2 29.2 31.5

Table 7 Catalyst F-O evaluation results

Reaction temperature, ℃ 480 490 500 510 520

WHSV 15.44 16.07 15.89 16.69 14.29

C/O ratio 2.99 3.39 3.75 4.05 4.50

H ₂ +C ₁ +C ₂ ,wt% 0.70 1.00 1.32 1.30 1.64

C ₃ +C ₄ ,wt% 16.7 20.2 22.9 24.2 26.9

Gasoline, weight % 48.0 51.1 49.4 49.9 47.8

Diesel, weight % 17.6 14.6 14.7 12.3 14.3

Heavy oil, wt% 15.0 10.9 9.7 9.9 7.1

Coke, wt% 1.8 2.1 2.0 2.4 2.3

Conversion rate, weight % 85.0 89.0 90.3 90.1 92.8

Octane number (chromatographic method) 91.4 91.4 92.3 92.6 93.9

Gasoline selectivity, % 56.5 57.4 54.7 55.4 51.5

Light oil selectivity, % 77.2 73.8 71.0 69.0 66.9

Coke selectivity, % 2.12 2.36 2.21 2.66 2.48

Dry gas selectivity, % 0.82 1.12 1.46 1.44 1.77

C ₃ +C ₄ selectivity, % 19.6 22.7 25.4 26.9 29.0

Claims (5)

1, a kind of fluidized catalytic cracking catalyst is characterized in that, described catalyzer is made up of new-type high silicon Y zeolite and inorganic oxide matrix, and the shared therein ratio of new-type high silicon Y zeolite is 10-50%, and sodium oxide content is less than 1.0% (weight), SiO in the zeolite ₂/ Al ₂O ₃Than being 6-40, relative crystallinity is greater than 80%; Inorganic oxide matrix can be selected from: aluminium oxide-silicon oxide, silica gel or silicon sol, aluminium glue or activated alumina, natural clay or their mixture; Described catalyzer is made by following method:

One, with SiO ₂/ Al ₂O ₃Than the NaY zeolite greater than 4.5 synthetic is raw material, and the method that adopts chemical dealuminization and two kinds of processes of hydrothermal treatment consists to combine and hocket prepares new-type high silicon Y zeolite by following graphic and condition:

Following formula represents that chemical glue aluminium and two kinds of processes of hydrothermal treatment consists can hocket arbitrarily repeatedly, and which is preparation process terminate in and depend on requirement to product property in step;

(1) chemical dealuminization: temperature is 25-100 ℃, handles Y zeolite 1-6 hour with the dealumination agent solution (its consumption calculates by required pre-dealuminzation degree) of 1-20% (weight), and dealumination agent is selected from organic acid, comprises ethylenediamine tetraacetic acid (EDTA), oxalic acid, sulphosalicylic acid; Organic and inorganic salt comprise ammonium oxalate, Neutral ammonium fluoride, ammonium silicofluoride, ammonium borofluoride, and each time chemical dealuminization process can be selected identical or different dealumination agent for use, carries out ammonium ion exchange in the time of chemical dealuminization;

(2) hydrothermal treatment consists: treatment temp 400-700 ℃, treatment time 1-3 hour, atmosphere water concentration 20-100% (volume) also can be zeolite self water vapor that contains 30-50% (weight) water;

(3) chemical dealuminization: select the condition in (1) for use;

(4) hydrothermal treatment consists: select the condition in (2) for use;

(5) chemical dealuminization: proceed the zeolite framework dealuminzation, then select the condition in (1) for use; When only taking off non-framework aluminum, then use 1-5% (weight) NH ₄F or (NH ₄) ₂C ₂O ₄Solution, consumption were handled zeolite 0.5-3 hour by every gram zeolite 5-10 ml soln under 50-100 ℃ of temperature;

Two, prepared new-type high silicon Y zeolite is levigate, mix dozen oar by its amount with water glass for the 10-50% elder generation of catalyst weight, add Tai-Ace S 150 and become glue, add sodium metaaluminate again after wearing out, aging again, add Tai-Ace S 150 at last and make system pH=3-4, add ammoniacal liquor again and transfer pH=5-6, after gel is crossed the homogeneous mill, spraying drying, wash again after thus obtained microsphere sieves and remove salinity, be drying to obtain described catalyzer again.

According to the catalyzer of claim 1, it is characterized in that 2, the sodium oxide content of wherein contained new-type high silicon Y zeolite is less than 0.5%(weight), SiO ₂/ Al ₂O ₃Than being 8-20, relative crystallinity is greater than 90%.

3, a kind of Preparation of catalysts method as claimed in claim 1 is characterized in that described method comprises:

One, with SiO ₂/ Al ₂O ₃Than the NaY zeolite greater than 4.5 synthetic is raw material, and the method that adopts chemical dealuminization and two kinds of processes of hydrothermal treatment consists to combine and hocket prepares new-type high silicon Y zeolite by following graphic and condition:

Following formula represents that chemical dealuminization and two kinds of processes of hydrothermal treatment consists can hocket arbitrarily repeatedly, and which is preparation process terminate in and depend on requirement to product property in step;

(1) chemical dealuminization: temperature is 25-100 ℃, uses 1-20%(weight) dealumination agent solution (its consumption calculates by required pre-dealuminzation degree) handled Y zeolite 1-6 hour, dealumination agent is selected from organic acid, comprises ethylenediamine tetraacetic acid (EDTA), oxalic acid, sulphosalicylic acid; Organic and inorganic salt comprise ammonium oxalate, Neutral ammonium fluoride, ammonium silicofluoride, ammonium borofluoride, and each time chemical dealuminization process can be selected identical or different dealumination agent for use, carries out ammonium ion exchange in the time of chemical dealuminization;

(2) also can be to contain 30-50%(weight hydrothermal treatment consists: treatment temp 400-700 ℃, treatment time 1-3 hour, atmosphere water concentration 20-100%(volume)) zeolite self water vapor of water;

(3) chemical dealuminization: select the condition in (1) for use;

(4) hydrothermal treatment consists: select the condition in (2) for use;

(5) chemical dealuminization: proceed the zeolite framework dealuminzation, then select the condition in (1) for use; When only taking off non-framework aluminum, then use 1-5%(weight) NH ₄F or (NH ₄) ₂C ₂O ₄Solution, consumption were handled zeolite 0.5-3 hour by every gram zeolite 5-10 ml soln under 50-100 ℃ of temperature;

Two, prepared new-type high silicon Y zeolite is levigate, mix making beating by its amount with water glass for the 10-50% elder generation of catalyst weight, add Tai-Ace S 150 and become glue, add sodium metaaluminate again after wearing out, aging again, add Tai-Ace S 150 at last and make system pH=3-4, add ammoniacal liquor again and transfer pH=5-6, after gel is crossed the homogeneous mill, spraying drying, wash again after thus obtained microsphere sieves and remove salinity, dry again that catalyzer is standby.

4, according to the method for preparing catalyst of claim 3, it is characterized in that,

One, the method for preparing new-type high silicon Y zeolite only chemical dealuminization and two kinds of processes of hydrothermal treatment consists are hocketed twice, and process condition is:

(1) chemical dealuminization: temperature is 50-100 ℃, the dealumination agent oxalic acid and/or the ammonium oxalate aqueous solution, its concentration is 2-10%(weight), its consumption calculates by pre-dealuminzation degree, and the treatment time is 2-4 hour;

(2) hydrothermal treatment consists: temperature is 400-700 ℃, and the time is 1-2 hour, and the atmosphere water concentration is the 20-80%(volume);

(3) chemical dealuminization: select the condition in (1) for use;

(4) hydrothermal treatment consists: select the condition in (2) for use;

Two, the content of new-type high silicon Y zeolite in catalyzer is 15-30%(weight).

5, according to the method for preparing catalyst of claim 3, it is characterized in that:

One, the method for preparing new-type high silicon Y zeolite is only carried out twice chemical dealuminization and a hydrothermal treatment consists, and its process condition is followed successively by:

(1) chemical dealuminization: temperature is 50-100 ℃, the dealumination agent oxalic acid and/or the ammonium oxalate aqueous solution, its concentration is 2-10%(weight), its consumption calculates by pre-dealuminzation degree, and the treatment time is 2-4 hour;

(2) hydrothermal treatment consists: temperature is 400-700 ℃, and the time is 1-2 hour, and the atmosphere water concentration is the 20-80%(volume);

(3) chemical dealuminization: temperature is 60-90 ℃, and the dealumination agent ammonium silicofluoride aqueous solution, its consumption are every gram zeolite 5%(weight) ammonium fluosilicate solution 1-4 milliliter, treatment time 2-4 hour;

Two, the content of new-type high silicon Y zeolite in catalyzer is 15-30%(weight).

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