CN1119390C - Process for preparing cracking catalyst of petroleum hydrocarbons - Google Patents

Abstract

The present invention provides a cracking catalyst preparing method which is characterized in that molecular sieve and/or aluminum colloidal sol are/is added before clay and inorganic acid, and the inorganic acid is added after the aluminium colloidal sol, preferably the inorganic acid is added after the aluminium colloidal sol and the quasi-thin diaspore, and the sequence of adding the rest materials has no specific limit. Moreover, catalyst slurry contains a viscosity reductant, wherein the viscosity reductant is ammonium dihydrogen or diammonium hydrogen phosphate or ammonium dihydrogen phosphate or the mixture thereof. The addition of the viscosity reductant is 0.1 to 2% of the weight of a dry basis of the catalyst. Compared with the method of the prior art, the method provided by the present invention can greatly improve the solid content of the catalyst slurry before a spray-drying step is carried out, and can shorten the sol forming time. Thereby, the production efficiency of the catalyst is improved, and the energy consumption and the production cost are reduced.

Description

A kind of preparation method of petroleum hydrocarbon cracking catalyst

The invention relates to a method for preparing a catalytic cracking catalyst used in petroleum processing.

Due to the heavy and inferior quality of raw oil, most of the current heavy oil fluid catalytic cracking (FCC) catalysts use semi-synthetic catalysts with high molecular sieve content (above 30% by weight). In order to ensure the anti-wear strength of the catalyst and improve its reaction selectivity, it is necessary to select a suitable binder. Adhesives used in the prior art mainly include pseudo-boehmite adhesives, composite silica-alumina adhesives, or composite aluminum-based adhesives composed of aluminum sol and pseudo-boehmite.

CN1098130A proposes a cracking catalyst and a preparation method thereof, wherein a composite aluminum-based adhesive composed of aluminum sol and pseudo-boehmite is used. Since the composite aluminum-based binder combines the characteristics of strong cracking ability of pseudo-boehmite macromolecules, good bonding performance of aluminum sol and good coke selectivity, most of the domestic heavy oil FCC catalysts currently use this composite aluminum-based binder. Binder. The preparation method of the cracking catalyst described in this patent is to firstly mix clay and deionized water for beating, add hydrochloric acid to acidify, then add pseudo-boehmite, then age the obtained slurry at 50-80°C for 0.5-2 hours, and after cooling , then add aluminum sol and molecular sieve slurry, mix evenly and spray dry. The disadvantages of this method are that due to the need for heating and aging, the preparation time is long, the energy consumption is large, and the solid content of the catalyst slurry before spray drying is low, generally less than 25% by weight, resulting in high energy consumption, low production efficiency and high production cost. If the solid content of the slurry is increased, it will not be able to be transported due to the high viscosity.

The cracking catalyst proposed in USP5,547,564 and its preparation method are to replace pseudo-boehmite with Bayerite and/or η-alumina, which can improve the heavy metal resistance and coke selectivity of the catalyst.

Increasing the solid content of the FCC catalyst slurry before spray drying can improve the production efficiency of the catalyst, reduce the energy consumption of spray drying, reduce the exhaust gas emission caused by fuel combustion, and reduce the amount of deionized water, thereby reducing the production cost of the catalyst. Improve product competitiveness.

U.S. Patent No. 4,476,239 and USP4,443,553 report a preparation method for cracking catalysts, which is characterized in that a viscosity reducer aluminum hydroxychloride or aluminum hydroxynitrate is added to the catalyst slurry to reduce the viscosity of the catalyst slurry and then increase the solid content of the catalyst slurry . According to the description therein, for the catalyst slurry containing aluminum-based binder, clay, silicon source and molecular sieve, the maximum solid content of the catalyst slurry is 20 to 25% by weight when no viscosity reducer is added. After adding the viscosity reducer, the maximum solid content of the catalyst slurry is The solids content can be up to 30% by weight. The preparation process is: ①water→②pseudoboehmite→③acid→④kaolin→⑤molecular sieve→⑥polyammonium silicate→⑦viscosity reducer Al ₂ (OH)5NO ₃ or Al ₂ (OH) ₅ Cl , the product is obtained by spray drying, washing and drying.

For the FCC catalyst that adopts pseudo-boehmite and aluminum sol composite aluminum-based binder, the production process reported by domestic and foreign patents all adopts the process of adding the aluminum sol after adding acid to peptize the pseudo-boehmite (such as CN1098130A, and Example 5) in USP5,547,564, the catalyst slurry has high viscosity and low solid content. Even if a viscosity reducer is added, the solid content of the slurry before spray drying is generally below 30% by weight.

The purpose of the present invention is to provide a method for preparing a cracking catalyst, which can greatly increase the solid content of the catalyst slurry before spray drying, thereby improving the production efficiency of the catalyst and reducing energy consumption and production costs.

The preparation method of the cracking catalyst provided by the present invention comprises mixing the molecular sieve slurry, aluminum sol, pseudo-boehmite, clay and inorganic acid to form a catalyst slurry, and then spray drying; it is characterized in that the molecular sieve and/or aluminum sol The clay and the inorganic acid are added before, the inorganic acid is added after the aluminum sol, preferably the inorganic acid is added after the aluminum sol and pseudo-boehmite, the order of adding the rest of the materials is not particularly limited, and the catalyst slurry contains a A kind of viscosity reducing agent; Wherein said viscosity reducing agent is ammonium phosphate, diammonium hydrogen phosphate or ammonium dihydrogen phosphate, or their mixture, and the addition amount of viscosity reducing agent is 0.1～2% of catalyst dry basis weight, preferably 0.3 ~1.5%; the weight ratio of the inorganic acid to Al ₂ O ₃ in the pseudo-boehmite is 0.02-0.25; the solid content of the catalyst slurry is 30-55% by weight.

In the preparation method of the cracking catalyst provided by the present invention, it is preferred to firstly mix the molecular sieve slurry, aluminum sol and pseudo-boehmite in any order and beat and mix evenly; then add clay, inorganic acid and reducing The viscous agent is beaten and mixed evenly; then the obtained catalyst slurry is spray-dried.

The preparation method of the cracking catalyst provided by the present invention is characterized in that the order of adding each raw material and adding a special viscosity reducer, and the composition of the catalyst slurry can be determined according to the formula of the specific catalyst, and the present invention has no special limits.

In the preparation method of the cracking catalyst provided by the present invention, the content (by weight on a dry basis) of each component in said catalyst slurry is preferably 10-50% of molecular sieve, 15-70% of clay, pseudoboehmite and aluminum sol ( Calculated by Al ₂ O ₃ ) 10-35%; wherein the weight ratio of pseudo-boehmite to aluminum sol Al ₂ O ₃ is (6:1)-(1:10), inorganic acid and pseudo-boehmite The weight ratio of Al ₂ O ₃ in the slurry is 0.02-0.25, and the solid content of the slurry is 30-55% by weight.

Said slurry in the method provided by the invention may also contain 0 to 10% by weight of one or more oxides selected from rare earth oxide, silicon oxide, magnesium oxide, titanium oxide, phosphorus oxide, aluminum oxide-silicon oxide or Precursors thereof; among them, rare earth oxides or silicon oxides or their precursors are preferred.

Said molecular sieve in the method provided by the present invention is Y-type zeolite or the mixture of Y-type zeolite and ZSM-5 zeolite, Omega zeolite, beta zeolite; Wherein preferred is Y-type zeolite or Y-type zeolite and ZSM-5 A mixture of zeolites.

Said clay in the method provided by the invention is kaolin, halloysite, sepiolite, cumulated clay, montmorillonite or their mixture; wherein preferably kaolin, halloysite, sepiolite or their mixture ; Most preferred is kaolin.

The pseudo-boehmite mentioned in the method provided by the invention can be replaced by boehmite, gibbsite, bayerite or η-alumina.

Said inorganic acid in the method provided by the invention is hydrochloric acid or sulfuric acid; Wherein preferred is hydrochloric acid.

The concentration of the molecular sieve slurry in the method provided by the invention is 250-550 g/liter.

The method provided by the present invention may also include the step of roasting or washing the catalyst obtained after spray drying.

In the preparation method of the petroleum cracking catalyst provided by the present invention, there may also be other schemes in accordance with the present invention other than the above-mentioned schemes.

Fig. 1 is the relationship between the viscosity of the catalyst slurry and the amount of diammonium hydrogen phosphate added (accounting for the percentage of the total weight of the catalyst dry basis) when the solid content of the catalyst slurry is about 50%.

The viscosity of the catalyst slurry depends on the solid content of the catalyst slurry, the composition of the catalyst slurry and the existing state of each component. For the FCC catalyst using a composite aluminum-based binder, the two most important factors affecting the viscosity of the catalyst slurry are the solid content of the catalyst slurry and the existence of pseudo-boehmite.

In the case of high catalyst slurry solid content, the most effective means to keep the catalyst slurry viscosity moderate is to control the existence state of pseudo-boehmite.

The technical key of the present invention is that the molecular sieve slurry and/or the aluminum sol are added before the clay, and the aluminum sol is added before the acid is added. Adding the molecular sieve slurry and/or aluminum sol first can make full use of the water in the molecular sieve slurry and/or aluminum sol to beat the clay so as to ensure that the catalyst slurry has a higher solid content. If the clay is beaten first, a large amount of water must be added. The water that must be contained in the molecular sieve slurry and aluminum sol added later will make it difficult to increase the solid content of the catalyst slurry; the buffering effect of the aluminum sol on the pH can be used to ensure that the addition of acid will not make the pH of the slurry too high. Low so as not to destroy the molecular sieve, can change the existence state of the pseudo-boehmite after peptization, and change the interaction between the colloidal particles, so that the viscosity of the slurry is greatly reduced; The gelling time is greatly shortened, and the viscosity of the slurry can be further reduced simultaneously; on the other hand, since the catalyst slurry in the method of the present invention also contains an ammonium phosphate viscosity reducer, the viscosity of the slurry can be further reduced, and the solid content of the slurry can be improved, while the ammonium phosphate The viscosity-reducing performance of the slurry is also a new discovery of the present invention; the solid content of the catalyst slurry can be as high as about 50% by weight by using the method of the present invention, which is beyond the reach of the prior art. In addition, the anti-wear strength and reaction performance of the catalyst obtained by the method of the present invention are not lowered compared with other methods in the prior art. Therefore, compared with the method in the prior art, the method provided by the invention can greatly improve the production efficiency of the catalyst, and reduce energy consumption and production cost.

The following examples will further illustrate the present invention, but the protection scope of the present invention is not limited by these examples.

In each embodiment and comparative example, Cole Parmer 98936 drum viscometer is used to measure slurry viscosity, and the given viscosity is the result of using R4 rotating shaft to measure under the rotating speed of 2.5rpm; Reactivity was measured according to RIPP28-90, RIPP29-90 and RIPP92-90 standard methods in "Petrochemical Analysis Methods (RIPP Test Method)" (edited by Yang Cuiding et al., Science Press, published in 1990).

Example 1-5

In the reactor, add the SRCY molecular sieve (commercial product of Changling _Oil Refinery and Chemical Plant Catalyst Factory, which is a rare earth HY type molecular sieve, _RE2O3 content of 13 wt. %, the same below) 11.2 kg of slurry and 14.2 kg of aluminum sol (commercial product obtained from the Changling Refinery and Chemical Catalyst Plant, with an alumina content of 21% by weight, the same below), after stirring evenly, add 7.6 One kilogram of pseudo-boehmite (commercial product of Shandong Aluminum Works, alumina content is 60% by weight, the same below), after beating and stirring for 30 minutes, add 25.4 kg of kaolin (commercial product of Suzhou Kaolin Company, 29% by weight, same below). ), after beating and stirring for 45 minutes, add diammonium hydrogen phosphate, the addition of diammonium hydrogen phosphate is 0.2% of the total weight of the catalyst on a dry basis, after stirring for 10 minutes, adding 0.3 kilograms of concentration is 30% by weight of hydrochloric acid, and beating again After stirring for 30 minutes, the viscosity of the catalyst slurry was measured, the obtained catalyst slurry was spray-dried, and the spray-dried product was roasted at 600°C for 20 minutes to obtain catalyst A. At this point, the catalyst slurry was relatively viscous.

According to the same formula and preparation steps as above, only the addition of diammonium hydrogen phosphate is changed to 0.5%, 0.8%, 1.0% and 1.2% of the total weight of the catalyst on a dry basis, respectively, to prepare catalysts B, C, D and E . Now the viscosity of the catalyst slurry significantly decreases with the increase of the diammonium hydrogen phosphate add-on, and the relationship between the viscosity of the catalyst slurry and the diammonium hydrogen phosphate add-on (accounting for the percentage of the total weight of the catalyst dry basis) is shown in Fig. 1 .

When the amount of diammonium hydrogen phosphate added was 0.3 kg (accounting for 1.0% of the total weight of the catalyst on a dry basis), the solid content of the obtained catalyst slurry was 50.9% by weight, and the viscosity of the slurry was 4900 centipoise; the wear index of the obtained catalyst was 1.9.

Example 6

In the reaction kettle, add the SRY molecular sieve (commercial product of Changling Oil Refinery and Chemical Plant Catalyst Factory with a concentration of 24.8% by weight, reduced by 2.6% by weight, which is an ultra-stable Y-type molecular sieve, with a particle diameter of less than 10 microns and a concentration of 24.8% by weight, which is an ultra-stable Y-type molecular sieve. Constant 2.455 nanometers, the same below) 14.1 kilograms of slurry and 2.9 kilograms of aluminum sol, after stirring evenly, add 4.0 kilograms of pseudo-boehmite therein under stirring, beating and stirring for 20 minutes, then add 1.01 kilograms of hydrochloric acid with a concentration of 21.5% by weight , and then add 4.9 kg of kaolin, beat and stir for 45 minutes, add 0.1 kg of ammonium dihydrogen phosphate, stir for 10 minutes, and then spray-dry the obtained catalyst slurry. The product obtained by spray drying was washed with water and air-dried to obtain catalyst F.

The solid content of the slurry before catalyst F spray drying is 37% by weight, the viscosity is 2300 centipoise, the obtained catalyst wear index is 1.8, the water drop method pore volume is 0.35 ml/g, and the micro-reaction activity is 72 (after aging at 800° C./4 hours) .

Example 7

Get 1.05 kilograms of ZRP-1 molecular sieves (the product of Zhoucun Catalyst Factory of Qilu Petrochemical Company, 5.0% by weight, ZSM-5 type molecular sieve, the same below) and 1.54 kilograms of DASY molecular sieves (commercial product of Zhoucun Catalyst Factory of Qilu Petrochemical Company, ignited 2.6% by weight, which is an ultra-stable Y-type molecular sieve with a unit cell constant of 2.452 nanometers, the same below), add 5.22 kg of deionized water, grind it with a colloid mill until the particle diameter is less than 10 microns, then add it to the reactor, and then add 2.9 kilograms of aluminum sol (the commercial product that obtains from Zhoucun Catalyst Factory of Qilu Petrochemical Company, aluminum oxide content is 21% by weight, the same below), stir evenly, then add 3.5 kilograms of pseudoboehmite (Shandong Aluminum Co., Ltd. factory commercial product, aluminum oxide content is 60% by weight, the same below), after stirring for 15 to 30 minutes, add 6.8 kilograms of kaolin (commercial product of Suzhou Kaolin Co., burning 29% by weight, same below) and 0.1 kilogram of diammonium hydrogen phosphate, After stirring for 45 minutes, add 0.85 kg of 21.5% by weight hydrochloric acid, beat for 30 minutes, spray dry, and roast the spray-dried product at 600° C. for 20 minutes to obtain catalyst G.

The solid content of the slurry before catalyst G spray drying is 45.7% by weight, the viscosity is 3500 centipoise, the obtained catalyst wear index is 1.5, the water drop method pore volume is 0.33 ml/g, and the microreactive activity is 62 (after aging at 800° C./4 hours) .

Comparative example 1

This comparative example illustrates the effect of preparing the catalyst according to the method of CN1098130A.

Add 21.8 kilograms of water in the reactor, then add 6.8 kilograms of kaolin and stir and beat for 90 minutes, then add 3.5 kilograms of pseudo-boehmite, add 0.64 kilograms of 27.8% by weight hydrochloric acid after stirring for 10 minutes, and heat up to Aging at 65°C for 2 hours, after the temperature drops below 50°C, add 2.9 kg of aluminum sol, beat for 25 minutes, then add the colloid-milled molecular sieve slurry (the molecular sieve slurry is made of 1.05 kg of ZRP-1 molecular sieve and 1.54 kg of DASY molecular sieve) 5.22 kg of deionized water), spray-dried after beating for 30 minutes, and the spray-dried product was roasted at 600° C. for 20 minutes to obtain catalyst H.

The solid content of the slurry before the catalyst H was spray-dried was 23% by weight, the viscosity was 17920 centipoise, the wear index of the obtained catalyst was 1.9, the pore volume of the water drop method was 0.27 ml/g, and the microreaction activity was 60 (after aging at 800° C./4 hours) .

Comparative example 2

Add 11.6 kg of water to the reaction kettle, then add 6.8 kg of kaolin and beat for 90 minutes, then add 3.5 kg of pseudo-boehmite, stir for 10 minutes, add 0.64 kg of 27.8% by weight hydrochloric acid, beat for 30 minutes and then heat up to 65°C Aging for 2 hours, after the temperature drops below 50°C, add 2.9 kg of aluminum sol, and after beating for 25 minutes, add the colloid-milled molecular sieve slurry (the molecular sieve slurry is composed of 1.05 kg of ZRP-1 molecular sieve and 1.54 kg of DASY molecular sieve plus 5.22 kg deionized water), beating for 30 minutes to obtain the slurry of catalyst I, the viscosity of this slurry was 84750 centipoise, and it could not be spray-dried because the viscosity was too large.

Catalyst I has a slurry solids content of 30% by weight

Example 8

Take 14.1 kg of ground SRY molecular sieve slurry with a concentration of 24.8% by weight and add it to the gelling reaction kettle, add 3.0 kg of pseudoboehmite under stirring, stir for 20 minutes, add 5.7 kg of aluminum sol, and stir for another 15 minutes Add 5.1 kilograms of halloysite (commercial product obtained from Changling Refinery and Chemical Plant Catalyst Factory) and 0.15 kilograms of diammonium hydrogen phosphate, stir after 45 minutes and add 0.670 kilograms of hydrochloric acid of 21.5 percent by weight, beating for 30 minutes Minutes later, it was spray-dried, and the spray-dried product was washed with water and air-dried to obtain Catalyst J.

The solid content of the slurry before catalyst J spray drying is 35% by weight, the viscosity is 2150 centipoise, the wear index of the obtained catalyst is 1.3, the pore volume of the water drop method is 0.39 ml/g, and the microreaction activity is 70 (after aging at 800°C/4 hours) .

Example 9

Add 14.1 kg of SRY molecular sieve slurry and 2.9 kg of aluminum sol with a concentration of 24.8% by weight and ground into the reaction kettle, add 4.0 kg of pseudoboehmite and 0.09 kg of ammonium dihydrogen phosphate to it under stirring, and after stirring for 20 minutes, Add 1.01 kg of 21.5% by weight hydrochloric acid, stir for 20 minutes, add 4.9 kg of kaolin, and stir for 45 minutes, then add 1.2 kg of silica sol (commercial product of Beijing Changhong Chemical Factory, _SiO2 content is 25% by weight), stir evenly and spray After drying, the spray-dried product was washed with water and air-dried to obtain catalyst K.

The solid content of the slurry before catalyst K spray drying is 37% by weight, the viscosity is 7530 centipoise, the obtained catalyst wear index is 1.9, the water drop method pore volume is 0.36 ml/g, and the microreaction activity is 71 (after aging at 800°C/4 hours) .

Example 10

In reactor, add 7.1 kilograms of aluminum sols (the commercial product that obtains from Changling Oil Refinery Chemical Plant Catalyst Factory, alumina content is 21 weight %) and 3.2 kilograms of water, add 2.5 kilograms of pseudoboehmite (Shandong Aluminum factory commercial product, aluminum oxide content is 60% by weight), after beating for 20 minutes, add 4.7 kilograms of kaolin (commercial product of Suzhou Kaolin Company, loss of 29% by weight) and 0.12 kilogram of diammonium hydrogen phosphate, add after stirring and beating for 45 minutes 0.55 kilograms of hydrochloric acid with a concentration of 22%, after beating for 30 minutes, add 0.158 kilograms of ZRP-5 molecular sieves that have been ground to a particle diameter of less than 10 microns with colloidal grinding (commercial products from the Catalyst Factory of Changling Oil Refinery and Chemical Plant, ignition reduction 5.1 % by weight, is a molecular sieve of ZSM-5 structure type), 1.80 kg of SRY molecular sieve (commercial product of Changling Petroleum Refinery and Chemical Plant Catalyst Factory, burning 2.6% by weight, is an ultra-stable Y-type molecular sieve, unit cell parameter 2.455 nanometers) and 1.79 kg of REUSY Molecular sieve (Changling Petroleum Refinery Chemical Plant Catalyst Factory commodity, 2.5% by weight, rare earth ultra-stable Y-type molecular sieve, rare earth oxide content is 7% by weight) and molecular sieve slurry composed of 6.68 kg of water, spray-dried after 30 minutes of beating, Catalyst L was obtained by roasting the spray-dried product at 600° C. for 20 minutes.

The solid content of the slurry before the catalyst L was spray-dried was 35%, and the slurry viscosity was 9500 centipoise; the wear index of the obtained catalyst was 1.7, the pore volume of the water drop method was 0.36ml/g, and the microreaction activity was 75 (after aging at 800° C./4 hours) .

Claims (15)

1. A preparation method for a cracking catalyst, the method comprising mixing molecular sieve slurry, aluminum sol, pseudo-boehmite, clay and inorganic acid beating uniformly to make catalyst slurry, and then spray drying; it is characterized in that molecular sieve and/or aluminum The sol is added before the clay and the inorganic acid, and the inorganic acid is added after the aluminum sol, and the order of addition of the remaining materials is not particularly limited, and the catalyst slurry contains a viscosity reducer; wherein the viscosity reducer is ammonium phosphate, Diammonium hydrogen phosphate or _ammonium dihydrogen phosphate, or their mixture, the addition of viscosity reducer is 0.1～2% of catalyst dry basis weight; said inorganic acid and _Al2O3 in pseudo-boehmite The weight ratio is 0.02-0.25; the solid content of the catalyst slurry is 30-55% by weight. 2. According to the preparation method of claim 1, it is characterized in that the inorganic acid is added after the alumina sol and pseudo-boehmite. 3. according to the preparation method of claim 1, it is characterized in that the method comprises first molecular sieve slurry, aluminum sol and pseudo-boehmite are mixed in any order and beating and mixed uniformly; then add clay, inorganic acid wherein in any order and viscosity reducer and beating and mixing evenly; then the obtained catalyst slurry is spray-dried. 4. according to the preparation method of claim 1, the content of molecular sieve, aluminum sol, pseudo-boehmite and clay by dry basis weight in said catalyst slurry is respectively molecular sieve 10～50%, clay 15～70%, 10-35% of pseudo-boehmite and aluminum sol based on the dry weight of _Al2O3 ; wherein the weight ratio of pseudo _- boehmite to _{aluminum sol} is 6:1-1:10. 5. According to the preparation method of claim 1, 2, 3 or 4, wherein said slurry also contains 0 to 10% by weight of rare earth oxide, silicon oxide, magnesium oxide, titanium oxide, phosphorus oxide, aluminum oxide-oxidized One or more oxides of silicon or their precursors. 6. The preparation method according to claim 5, wherein said slurry further contains 0 to 10% by weight of rare earth oxide or silicon oxide or their precursors. 7. The preparation method according to claim 1, wherein said molecular sieve is Y-type zeolite or a mixture of Y-type zeolite and one of ZSM-5 zeolite, Omega zeolite and beta zeolite. 8. The preparation method according to claim 7, wherein said molecular sieve is Y-type zeolite or a mixture of Y-type zeolite and ZSM-5 zeolite. 9. The preparation method according to claim 1, wherein said clay is kaolin, halloysite, sepiolite, cumulated clay, montmorillonite or a mixture thereof. 10. The preparation method according to claim 9, wherein said clay is kaolin, halloysite, sepiolite or a mixture thereof. 11. The preparation method according to claim 10, wherein said clay is kaolin. 12. The preparation method according to claim 1, wherein said pseudo-boehmite is replaced with boehmite, gibbsite, bayerite or η-alumina. 13. The production method according to claim 1, wherein said inorganic acid is hydrochloric acid or sulfuric acid. 14. The production method according to claim 13, wherein said inorganic acid is hydrochloric acid. 15. The preparation method according to claim 1, wherein the concentration of said molecular sieve slurry is 250-550 g/liter.

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