CN1353165A - Cocatalyst for cracking hydrocarbons - Google Patents

Abstract

A catalyst for catalytic cracking of hydrocarbons, containing 20-80% by weight of clay matrix, 10-40% by weight of inorganic oxide binder, 0-30% by weight of Y-type zeolite and 10-50% by weight of beta zeolite ; It is characterized in that wherein said zeolite beta contains 1 to 8% by weight of alkali metals or alkaline earth metals in terms of oxides based on the zeolite beta. The catalyst can maintain coke and dry gas selectivity while reducing oil slurry yield and increasing light oil yield.

Description

A kind of hydrocarbon cracking co-catalyst

The present invention relates to a cocatalyst for catalytic cracking of hydrocarbons, in particular to a cocatalyst for catalytic cracking of hydrocarbons containing beta zeolite.

Increasing the yield of light oil and reducing the yield of oil slurry is the long-term goal of the oil refining industry, especially the fluid catalytic cracking (FCC) unit. There are a number of ways to achieve this to varying degrees. Over the years, many improvements or developments in the catalytic cracking process have been carried out around this purpose. Although the process modification can greatly increase the yield of light oil and reduce oil slurry, it requires a lot of investment. However, measures taken in catalytic cracking catalysts, especially additives, have the characteristics of less investment and quick results, and are very suitable for use in existing catalytic devices. Such as USP5,961,817 by introducing gibbsite (gibbsite) and silica sol binder in the catalyst matrix to make the catalyst produce a large number of 3-30nm mesopores, thereby improving the oil slurry cracking ability of the catalyst and reducing coke, but the magnitude is small . WO97/12011 reported a bottom oil cracking aid (BCA) and its preparation method, which is actually a SiO ₂ modified with Al ₂ O ₃ , acid-dispersed Al ₂ O ₃ and undispersed Al ₂ O The amorphous silicon-aluminum compound composed of O ₃ has the characteristics of high acidity and large pore size. According to J.Oil & Gas, 96 (2), 54, 1998, when the addition of BCA is 3% by weight, it can Improve light recovery by 2% by weight, and reduce SOx emissions in flue gas at the same time. However, the characteristics of high aluminum content and high acidity will inevitably lead to an increase in the amount of coke and gas (Petroleum Refining and Chemical Industry, 27(11), 68, 1996), which is unacceptable for industrial units, especially those limited by coke .

Hydrocarbon catalytic cracking catalysts containing beta zeolite have been reported. For example, USP4,898,846 proposes a cracking catalyst containing large-pore zeolite such as beta zeolite and ZSM-20 zeolite. Using this catalyst can increase the octane number of product gasoline; USP4,985,384 proposes an FCC catalyst containing zeolite beta, wherein the zeolite beta contains 0.1-15% by weight of gallium, zinc or a mixture thereof, the use of this catalyst can improve the aromatics selectivity of product gasoline. USP4,985,384 discloses a catalytic cracking catalyst containing zeolite beta modified by Zn, Ga or their mixture, which is introduced into zeolite beta by ion exchange, impregnation, deposition and other methods by 1 to 2% by weight, no more than 15% by weight. The weight percent of Zn and Ga makes the catalyst have good aromatics selectivity in the catalytic cracking reaction, and further improves the gasoline octane number. However, there is no report on the use of alkali metals or alkaline earth metals to modify β zeolite and use it in catalytic cracking to reduce oil slurry and increase light oil yield.

The purpose of the present invention is to provide a hydrocarbon catalytic cracking co-catalyst, which can maintain the selectivity of coke and dry gas while reducing the yield of oil slurry and increasing the yield of light oil.

The hydrocarbon catalytic cracking co-catalyst provided by the present invention contains 20-80, preferably 30-70 wt % of clay matrix, 10-40, preferably 15-30 wt % of inorganic oxide binder, 0-30, preferably 0 ~15% by weight of Y-type zeolite and 10-50, preferably 15-35% by weight, of zeolite beta; characterized in that said zeolite beta contains 1-8% by weight, preferably 1.5-6% by weight, based on the zeolite beta An alkali or alkaline earth metal (on an oxide basis).

The clay matrix mentioned in the catalytic cracking cocatalyst provided by the present invention is a clay matrix commonly used in cracking catalysts, and the present invention has no special limitation to it, and may be kaolin, halloysite, montmorillonite, sepiolite, etc.

Said inorganic oxide binding agent in the catalytic cracking cocatalyst provided by the present invention is the commonly used inorganic oxide binding agent in the cracking catalyst, and the present invention has no special limitation to it, and commonly used binding agent comprises silica sol, Alumina sol, acid-peptized pseudo-boehmite, silica-alumina colloid, and mixtures thereof; among them, alumina sol, acidified pseudo-boehmite, silica sol, and mixtures thereof are preferred.

The Y-type zeolite mentioned in the catalytic cracking co-catalyst provided by the present invention is a variety of Y-type zeolites commonly used in cracking catalysts, and the present invention has no special limitation to it, such as REY, REHY, REUSY, USY and the like.

The beta zeolite in the catalytic cracking cocatalyst provided by the present invention is not particularly limited, and its molar ratio of silicon to aluminum may be 20-200, preferably 25-80.

The alkali metal in the catalytic cracking cocatalyst provided by the present invention includes Li, Na, K, Rb, Cs, preferably K or Rb; the alkaline earth metal includes Be, Mg, Ca, Sr, Ba, preferably Mg or Ca.

The preparation method of said beta zeolite containing alkali metals or alkaline earth metals in the catalytic cracking cocatalyst provided by the present invention can be: the Naβ zeolite synthesized is ammonium exchanged two to three times according to a conventional method, so that the Na on the zeolite _O The content is less than 2% by weight, preferably less than 1% by weight; the β zeolite after the above-mentioned ammonium exchange is placed in a muffle furnace and roasted at 400-650°C for 0.5-6 hours to convert it into a hydrogen form; then the roasted Add the final product into an aqueous solution of alkali metal salt or alkaline earth metal salt, stir and exchange at 65-110°C for 0.5-4 hours, filter while it is hot, or perform an ion exchange of alkali metal or alkaline earth metal under the same conditions; wash and dry ; and then hydrothermally treated at 500-850° C. for 0.5-6 hours under a steam atmosphere.

The preparation method of the catalytic cracking co-catalyst provided by the present invention can be: mixing the inorganic oxide binder and clay for beating, and then adding the beta zeolite slurry containing alkali metal or alkaline earth metal, or beta zeolite containing alkali metal or alkaline earth metal The mixed slurry with Y-type zeolite is beaten and mixed evenly, then spray-dried to shape, then slurried and washed with hot deionized water for two to three times, and dried to obtain the co-catalyst provided by the present invention.

The catalytic cracking co-catalyst provided by the invention can not only reduce the yield of oil slurry and increase the yield of light oil, but also maintain good coke and dry gas selectivity when used in hydrocarbon catalytic cracking reactions.

The following examples will further illustrate the present invention.

The chemical composition of the product zeolite in each example and comparative example was determined by X-ray fluorescence spectrometry. Surface area and pore volume were determined by Micromeritics ASAP2400 low-temperature nitrogen adsorption instrument (BET method). The fluidized wear rate of the cocatalyst was measured by the Jersey index method (J.I.), and the apparent heap ratio was analyzed by conventional methods. The gasoline octane number is analyzed by chromatography.

Example 1

This example illustrates the preparation of metal-containing zeolite beta.

117.6g Naβ zeolite former powder (85% by weight on a dry basis, produced by Changling Oil Refining and Chemical Co., Ltd. Catalyst Factory, silicon-alumina ratio 28) was added to 2000ml 5% by weight of ammonium sulfate aqueous solution at 95°C and stirred and exchanged for one hour. After filtration, the same method is used to exchange twice, and the resulting filter cake is dried at 110-130°C, and then put into a box-type muffle furnace and roasted at 540°C for 2 hours to obtain hydrogen-type zeolite beta.

Take 10g (dry basis) of the above-mentioned hydrogen-type beta zeolite, add in 200ml of 3% by weight potassium chloride aqueous solution, ion exchange at 90°C for 2 hours under stirring, filter, and add 200ml of 2.5% by weight of potassium chloride aqueous solution to the filter cake, Ion exchange at 90°C for 2 hours with stirring, filter, wash with deionized water at 65°C for 3 times, and dry in an oven at 110-130°C.

The above-mentioned potassium-containing zeolite after drying is placed in a tubular muffle furnace and roasted for 2 hours at 650°C with water vapor (space velocity 3.0 hours ⁻¹ ) to obtain K-containing β zeolite, which is denoted as Kβ zeolite, and its physical and chemical properties are listed in in Table 1.

Example 2

Get 10g (dry basis) of the hydrogen-type zeolite beta prepared in Example 1, add 2% by weight of rubidium chloride aqueous solution 200ml, and ion-exchange at 90°C for 2 hours under stirring, filter, and add 8% by weight of zeolite to the filter cake. Rubidium chloride aqueous solution 200ml, ion exchange at 90°C for 2 hours with stirring, filter, wash with deionized water at 65°C for 3 times, and dry in an oven at 110-130°C.

The above-mentioned rubidium-containing zeolite after drying was placed in a tubular muffle furnace and calcined for 2 hours at 650°C with water vapor (space velocity 3.0 hours ^-1 ) to obtain Rb-containing β zeolite, which was denoted as Rbβ zeolite, and its physical and chemical properties were listed in in Table 1.

Example 3

Take 10g (dry basis) of the hydrogen-type beta zeolite prepared in Example 1, add 6% by weight of magnesium chloride aqueous solution to 200ml, ion exchange at 90°C for 2 hours under stirring, filter, and add 4% by weight of magnesium chloride aqueous solution to the filter cake 200ml, ion-exchange at 90°C for 2 hours with stirring, filter, wash with deionized water at 65°C for 3 times, and dry in an oven at 110-130°C.

The dried above-mentioned magnesia-containing zeolite is placed in a tubular muffle furnace and roasted for 2 hours at 650°C with water vapor (space velocity 3.0 hours ^-1 ), to obtain Mg-containing zeolite beta, which is denoted as Mgbeta zeolite, and its physical and chemical properties are listed in in Table 1.

Example 4

Get 10g (dry basis) of the hydrogen-type zeolite beta prepared in Example 1, add 8% by weight of calcium chloride aqueous solution 200ml, ion exchange at 90°C for 2 hours under stirring, filter, and add 6% by weight of zeolite to the filter cake. Calcium chloride aqueous solution 200ml, ion exchange at 90°C for 2 hours with stirring, filter, wash with deionized water at 65°C for 3 times, and dry in an oven at 110-130°C.

The above-mentioned calcium-containing zeolite after drying was placed in a tubular muffle furnace and calcined for 2 hours at 650°C with water vapor (space velocity 3.0 hours ⁻¹ ), to obtain Ca-containing β zeolite, which was denoted as Caβ zeolite, and its physical and chemical properties were listed in in Table 1.

Comparative example 1

This comparative example illustrates the preparation of zeolite beta free of alkali metals or alkaline earth metals.

Get 10g (dry basis) of the hydrogen-type zeolite beta prepared in Example 1 and place it in a tubular muffle furnace at 650°C for steam (space velocity 3.0 hours ⁻¹ ) to roast for 2 hours to obtain steam-treated hydrogen Type β zeolite, denoted as Hβ zeolite, its physical and chemical properties are listed in Table 1.

Table 1 sample Kβ Rbβ Mgβ Caβ Hβ Composition analysis (weight %) Na ₂ OAl ₂ O ₃ M _n O ^* 0.045.044.96 0.064.985.53 0.054.824.86 0.074.784.36 0.075.11-- XRD crystal retention (%) (compared with the sample before water baking) 95 96 95 94 95 ^* For Group IA, n=2; For Group IIA, n=1

Example 5

This example illustrates the results of heavy oil micro-reaction evaluation of zeolite beta modified by different metal ions.

The obtained Kβ, Rbβ, Mgβ, Caβ and Hβ zeolites of Examples 1 to 4 and Comparative Example 1 are respectively represented by β zeolite: Y-type zeolite (produced by the Catalyst Factory of Changling Oil Refining and Chemical Co., Ltd., the trade mark is PSRY): kaolin: aluminum Sol (Al ₂ O ₃ concentration 21.1% by weight, produced by Hunan Jianchang Petrochemical Co., Ltd.) (calculated as Al ₂ O ₃ )=4: 36: 40: 20 (weight) ratio mixed uniformly, then spray-dried and formed, and then Slurry and wash 3 times at 65°C with deionized water 20 times the weight of the catalyst on a dry basis. After drying, aging treatment at 800°C and 100% water vapor atmosphere for 4 hours, and then react on the heavy oil micro-reactor evaluate.

The conditions for heavy oil micro-reaction evaluation are: Changling Luning Pipeline Vacuum Gas Oil (VGO) as raw material, catalyst loading 4.0 g, catalyst-oil ratio 3.0, space velocity 16 hours ^-1 , reaction temperature 482 °C. The reaction evaluation results of the five catalyst samples are listed in Table 2. The results in the table show that the beta zeolite provided by the present invention has better heavy oil cracking ability compared with unmodified beta zeolite, and the gasoline octane number is comparable , and has good coke and dry gas selectivity.

Table 2 Molecular Sieve Number Kβ Rbβ Mgβ Caβ Hβ Product Distribution Weight % Dry gas Liquefied gas Gasoline Diesel Heavy oil Coke 1.3512.2957.2116.899.702.54 1.3312.1657.0716.969.972.51 1.3012.0856.7517.1410.252.48 1.2811.9556.6217.2610.432.46 1.2911.1055.6417.0712.532.48 Conversion rate, weight % 73.39 73.07 72.61 72.31 70.39 Coke/Conversion, % Dry Gas/Conversion, % Gasoline Octane RONMON 3.461.8488.979.8 3.441.8288.879.5 3.421.7988.779.6 3.401.7788.779.6 3.521.8388.879.6

Example 6

Get 482g kaolin (83% by weight on a dry basis, produced by Suzhou China Kaolin Company) and add it to 952g metal aluminum sol ( _Al2O3 concentration _21.1 % by weight, produced by Hunan Jianchang Petrochemical Co., Ltd.) under stirring, after stirring for 30 minutes Add 1143g of Kβ zeolite (prepared by Example 1) slurry with a solid content of 35% by weight, mix uniformly, homogeneously, spray dry, and the molded catalyst is washed and dried to obtain the co-catalyst of the present invention. Its physicochemical properties are listed in in Table 3.

Example 7

Get 361g kaolin (83% by weight on a dry basis, produced by China Kaolin Company in Suzhou) and join in 3750g silica sol (SiO ₂ concentration 8.0% by weight) under vigorous stirring, adding solid content after 30 minutes is 35% by weight of Kβ zeolite (made by Embodiment 1 preparation) slurry 1143g, mix homogeneously, homogeneous, spray dry, shape catalyst is through washing again, dry, obtain the said co-catalyst of the present invention, its physicochemical properties are listed in table 3.

Example 8

Get 361g kaolin (83% by weight on a dry basis, produced by Suzhou China Kaolin Co., Ltd.) and add it to 1143g of Kβ zeolite (prepared by Example 1) slurry with a solid content of 35% by weight under stirring, and add 154g pseudoboehmite after stirring for 30 minutes Limestone (65% by weight on a dry basis, produced by Shandong Aluminum Plant), after stirring evenly, slowly add 32g of industrial hydrochloric acid with a concentration of 31% by weight, so that the pH value of the slurry reaches 3.0±0.2, and then add 474g of metal aluminum sol (Al ₂ O ₃ Concentration 21.1% by weight, produced by Hunan Jianchang Petrochemical Co., Ltd.), mixed uniformly, homogeneously, spray-dried, and the molded catalyst was washed and dried to obtain the cocatalyst of the present invention, and its physicochemical properties are listed in Table 3.

Example 9

Get 361g kaolin (83% by weight on a dry basis, produced by Suzhou China Kaolin Company) and join 1143g of Kβ zeolite (prepared by Example 1) slurry with a solid content of 35% by weight under stirring, add 154g pseudo-thin water after stirring for 30 minutes Bauxite (dry basis 65% by weight, produced by Shandong Aluminum Factory), after stirring evenly, slowly add 32g of industrial hydrochloric acid with a concentration of 31% by weight to make the pH value of the slurry reach 3.0 ± 0.2, then add 1250g of silica sol (SiO Concentration _8.0 % by weight), mixed uniformly, homogeneously, spray-dried, and the molded catalyst was washed and dried to obtain the cocatalyst of the present invention, and its physicochemical properties are listed in Table 3.

Example 10

Get 482g kaolin (83% by weight on a dry basis, produced by Suzhou China Kaolin Company) and add it to 952g metal aluminum sol ( _Al2O3 concentration _21.1 % by weight, produced by Hunan Jianchang Petrochemical Co., Ltd.) under stirring, after stirring for 30 minutes Adding the mixed slurry (Kβ:PSRY=3:1) of Kβ zeolite (prepared by embodiment 1) and ultra-stable Y zeolite (produced by Changling Oil Refining and Chemical Co., Ltd. Catalyst Factory, trade mark PSRY) with a solid content of 35% by weight 1143g, mixed uniformly, homogeneously, spray-dried, and the molded catalyst was washed and dried to obtain the cocatalyst of the present invention, and its physicochemical properties are listed in Table 3.

Example 11

Get 482g kaolin (83% by weight on a dry basis, produced by Suzhou China Kaolin Company) and add it to 952g metal aluminum sol ( _Al2O3 concentration _21.1 % by weight, produced by Hunan Jianchang Petrochemical Co., Ltd.) under stirring, after stirring for 30 minutes Add 1143g of Mgβ zeolite (prepared by Example 3) slurry with a solid content of 35% by weight, mix uniformly, homogeneously, spray dry, and the molded catalyst is washed and dried to obtain the cocatalyst of the present invention. Its physicochemical properties are listed in in Table 3.

Comparative example 2

Get 482g kaolin (83% by weight on a dry basis, produced by Suzhou China Kaolin Company) and add it to 952g metal aluminum sol ( _Al2O3 concentration _21.1 % by weight, produced by Hunan Jianchang Petrochemical Co., Ltd.) under stirring, after stirring for 30 minutes Add 1143g of Hβ zeolite (prepared by comparative example 1) slurry with a solid content of 35% by weight, mix uniformly, homogeneously, spray dry, and the molded catalyst is washed and dried to obtain a cocatalyst for comparison, and its physicochemical properties are listed in Table 3.

Comparative example 3

This comparative example provides a kind of bottom oil cracking aid (prepared according to the method described in WO97/12011) that is produced by the brand name BCA-105 produced by the U.S. INTERCAT company, and is used as a contrast agent of the present invention, and its physicochemical properties are listed in Table 3.

table 3 sample Example 6 Example 7 Example 8 Example 9 Example 10 Example 11 Comparative example 2 Comparative example 3 Composition analysis (weight %) Na ₂ OAl ₂ O ₃ K ₂ O 0.1039.51.95 0.2515.81.98 0.1244.71.89 0.1835.52.01 0.0840.32.16 0.0839.21.75 ^* 0.1141.6/ 0.2763.1/ Surface area, m ² /g pore volume, ml/g apparent bulk ratio, g/ml wear index (JI), h ^-1 % 2250.180.681.8 1980.160.722.8 2360.200.691.9 2610.230.672.0 2190.190.692.1 2180.170.702.0 2110.170.702.3 1070.350.783.8 ^* MgO content

Example 12

This example illustrates the heavy oil cracking performance of the co-catalyst provided by the present invention in the catalytic cracking reaction.

After the cocatalysts of Examples 6, 9, 11 and Comparative Examples 2 and 3 were aged at 800° C. and 100% steam for 17 hours, the reaction was evaluated in a small fixed fluidized bed device. The evaluation method is to mix the CHZ-4 balancer (taken from the second set of heavy oil catalytic unit of Changling Oil Refining and Chemical Co., Ltd.) with the above-mentioned additives according to the weight ratio of balancer: additive = 90:10 to evaluate . The evaluation conditions are: reaction temperature 500°C, agent-oil ratio 5.0, space velocity 10 hours ^-1 , raw material oil is Changling-Lunning pipeline vacuum residue oil: vacuum wax oil = 20:80 mixed oil, see Table 4; Evaluation results are shown in Table 5. As can be seen from the data in Table 5, the auxiliary agent provided by the present invention is compared with the unmodified β zeolite auxiliary agent and the existing tower bottom oil cracking auxiliary agent BCA-105, and the heavy oil conversion capacity is greatly improved, and the coke And dry gas selectivity is better, and gasoline octane number is equal or improved.

Table 4

Raw oil properties:

Initial boiling point: 226°C 50v% Distillation point: 466°C

Density (20°C): 0.9015g/cm ³ Viscosity (80°C): 21.5 centipoise

Carbon residue: 2.86% by weight

Heavy metal (ppm): Fe Ni Cu V Na

                                                                     

table 5 sample CHZ-4 Balancer Balancer+Example 6 Balancer + Example 9 Balancer+Example 11 Balancer + comparative example 2 Balancer+BCA-105 Product Distribution Weight % Dry gas Liquefied gas Gasoline Diesel Heavy oil Coke 1.9311.7650.1519.5611.774.85 1.9314.0851.1518.328.935.61 1.9014.1551.3318.208.965.45 1.9013.7150.8318.599.485.50 1.8913.1749.3219.2411.105.29 2.5713.0449.3518.459.866.73 Conversion rate, weight % 68.68 72.76 72.83 71.94 69.66 71.69 Coke/Conversion, % Coking Factor ^* Dry Gas/Conversion, % Gasoline Octane RONMON 7.062.212.8180.490.1 7.712.102.6581.591.9 7.482.032.6181.492.3 7.652.152.6481.391.8 7.592.302.7181.091.4 9.392.853.5880.590.1 ^* Coking factor=coke/K, K=conversion rate/(1-conversion rate)

Claims (9)

1. A cocatalyst for catalytic cracking of hydrocarbons, containing 20-80% by weight of clay matrix, 10-40% by weight of inorganic oxide binder, 0-30% by weight of Y-type zeolite and 10-50% by weight of Beta zeolite; characterized in that said beta zeolite contains 1 to 8% by weight of alkali metals or alkaline earth metals in terms of oxides based on the beta zeolite. 2. The co-catalyst according to claim 1, which catalyst contains 30-70% by weight of clay matrix, 15-30% by weight of inorganic oxide binder, 0-15% by weight of Y-type zeolite and 15-35% by weight beta zeolite. 3. The cocatalyst according to claim 1, wherein said zeolite beta contains 1.5 to 6% by weight of alkali metal or alkaline earth metal in terms of oxide, based on the zeolite beta. 4. A cocatalyst according to claim 1, wherein said clay matrix is kaolin, halloysite, montmorillonite or sepiolite. 5. The cocatalyst according to claim 1, wherein said inorganic oxide binder is silica sol, alumina sol, acid peptized pseudo-boehmite, silica-alumina colloid or mixtures thereof. 6. The cocatalyst according to claim 5, wherein said inorganic oxide binder is alumina sol, acidified pseudoboehmite, silica sol or mixtures thereof. 7. The cocatalyst according to claim 1, wherein said Y-type zeolite is REY, REHY, REUSY or USY. 8. The cocatalyst according to claim 1, wherein said zeolite beta has a silicon-aluminum molar ratio of 20-200. 9. The cocatalyst according to claim 1, wherein said alkali metal is K or Rb; said alkaline earth metal is Mg or Ca.