CN109513420B

CN109513420B - Metal trapping agent, preparation method thereof and catalytic cracking method

Info

Publication number: CN109513420B
Application number: CN201710847920.0A
Authority: CN
Inventors: 张杰潇; 孙敏; 张万虹; 李家兴; 严加松; 田辉平
Original assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Current assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Priority date: 2017-09-19
Filing date: 2017-09-19
Publication date: 2021-09-07
Anticipated expiration: 2037-09-19
Also published as: CN109513420A

Abstract

The invention discloses a metal trapping agent, a preparation method thereof and a catalytic cracking method. The metal collector contains magnesium oxide and aluminum oxide, wherein at least part of the magnesium oxide and at least part of the aluminum oxide form a magnesium aluminate spinel structure, and the content of the magnesium oxide is more than 38 wt% based on 100% of the total weight of the metal collector; the metal collector has a bulk density of less than 0.85g/cm³The abrasion index is below 2%/h. The metal trapping agent provided by the invention is used for high-vanadium heavy oil catalytic cracking, can slow down the damage of vanadium to a cracking catalyst, improves the yield of liquid products, and simultaneously reduces the yield of dry gas and/or coke.

Description

Metal trapping agent, preparation method thereof and catalytic cracking method

Technical Field

The invention relates to the field of catalytic cracking, in particular to a metal trapping agent, a preparation method of the metal trapping agent and a catalytic cracking method adopting the metal trapping agent.

Background

The deepening of the heavy degree of crude oil further increases the processing cost of a refinery, at present, catalytic cracking is an important means for processing heavy oil of the refinery, and in order to reduce the cost and maximize the production benefit, the deep processing of the heavy oil and the processing of inferior crude oil can be realized.

However, poor crudes generally have high heavy metal (e.g., vanadium) content. Vanadium-containing compounds in petroleum are a very complex class of metal complexes, typically in the form of vanadium porphyrins and non-vanadium porphyrins. The boiling point of metalloporphyrin is generally between 565 ℃ and 650 ℃, and the metalloporphyrin is mainly concentrated in the residual oil, but enters the catalytic cracking fraction due to the stronger volatility. The non-porphyrin vanadium metal compound may be associated with asphaltene macromolecule and have a relative molecular weight of less than 400, and the ligand may be 4N, NO₂S or 4S; when the three-dimensional structure of the asphaltene macromolecules is destroyed, these small molecules are released. The contamination of the catalytic cracking catalyst with vanadium is mainly the irreversible destruction of the catalyst by vanadium. Experiments have shown that 1000ppm vanadium deposited on the equilibrator is sufficient to cause damage to the molecular sieve, causing damage to the distribution of the catalytically cracked products.

At present, a metal vanadium replenishing agent (metal trapping agent) is generally used for trapping heavy metals so as to reduce the damage of the heavy metals (such as metal vanadium) to the cracking catalyst. Spinel is a commonly used material for metal traps, e.g. US5603823A discloses a vanadium trap consisting of (a)15-60 wt% MgO, (b)30-60 wt% Al₂O₃And (c)10-30 wt% of rare earth. The rare earth is selected from lanthanum oxide and/or neodymium oxide, wherein at least part of MgO and Al₂O₃Mg-Al spinel is formed.

CN201210420784.4 provides a metal trapping agent, a preparation method and application thereof, wherein the bulk density of the metal trapping agent is 0.85-1.2g/cm³. The invention provides a catalytic cracking method, which comprises the following steps: under the catalytic cracking condition, heavy oil raw material is contacted with a catalyst mixture containing a metal collector and a catalytic cracking catalyst, wherein the metal collector is the metal collector disclosed by the invention. CN 201310236838.6 provides a metal trapping agent and a catalytic cracking method, wherein the metal trapping agent is prepared by the following steps: (1) mixing the small-pore aluminaMixing deionized water and acid for pulping to obtain first slurry; (2) contacting the first slurry with magnesium hydroxide and/or magnesium oxide to obtain a second slurry; (3) contacting the second slurry with macroporous alumina to obtain a third slurry; (4) carrying out spray drying on the third slurry, and roasting to obtain a solid; (5) and (3) contacting the solid with a water-soluble magnesium source solution, and roasting the contacted mixture after drying or not drying.

Because crude oil is more and more seriously degraded and the heavy metal content is higher, how to improve the physical and chemical properties of the metal trapping agent and optimize the action effect of the metal trapping agent at present becomes an important direction for the development of the metal trapping agent.

Disclosure of Invention

The invention aims to overcome the problems in the prior art and provide a metal trapping agent, a preparation method thereof and a catalytic cracking method thereof, so as to improve the physical and chemical properties of the metal trapping agent and improve the synergistic effect of the metal trapping agent and a catalyst.

In the research on the metal trapping agent, the inventor of the invention finds that the abrasion index is increased along with the increase of the content of magnesium oxide in the metal trapping agent; the content of the magnesium oxide has a direct relation with the action effect of the metal trapping agent, and if the content of the magnesium oxide can be increased and the abrasion index can be reduced, the effect of the metal trapping agent can be optimized; meanwhile, the use of the metal trapping agent is generally accompanied with the use of a catalyst, and as the bulk density of the metal trapping agent increases, the sulfidation effect and the reaction performance of the catalyst are affected when the metal trapping agent is used in combination with the catalyst, which requires that the bulk density of the metal trapping agent is not excessively large.

In order to achieve the above object, in a first aspect, the present invention provides a metal collector, which contains magnesium oxide and aluminum oxide, wherein at least part of the magnesium oxide and at least part of the aluminum oxide form a magnesium aluminate spinel structure, and the content of the magnesium oxide is more than 38 wt% based on 100% of the total weight of the metal collector; the metal collector has a bulk density of less than 0.85g/cm³The abrasion index is below 2%/h.

In a second aspect, the present invention provides a method for producing a metal trapping agent, the method comprising: mixing a first aluminum source, magnesium-aluminum sol, a magnesium source, optional clay, optional acid and optional solvent to prepare slurry, drying and roasting to obtain the metal trapping agent; wherein, Mg in the magnesium aluminum sol: the molar ratio of Al is (1.5-6): (1-2), preferably (4-6): 1, and the ratio of Al in the magnesium aluminum sol: the mol ratio of Cl is (1-1.5): 1.

in a third aspect, the present invention provides a metal trapping agent obtained by the production method according to the present invention.

In a fourth aspect, the present invention provides a use of a metal trap according to the present invention in catalytic cracking.

In a fifth aspect, the present invention provides a catalytic cracking process comprising: contacting a heavy oil feedstock with a mixture comprising a metal collector and a catalytic cracking catalyst under catalytic cracking conditions, wherein the metal collector is a metal collector according to the present invention.

By applying the metal trapping agent, the preparation method thereof and the catalytic cracking method, the metal trapping agent is prepared by adding the specific magnesium-aluminum sol, the physicochemical property of the metal trapping agent can be optimized under the conditions that the content of magnesium oxide is relatively increased and the stacking density is relatively reduced, and the abrasion index is particularly reduced and is enabled to be below 2%/h.

Meanwhile, the metal trapping agent provided by the invention has a good metal trapping effect, for example, when the metal trapping agent provided by the invention is used for high-vanadium heavy oil catalytic cracking, the damage of vanadium to a cracking catalyst can be relieved, the yield of liquid products is improved, and the yield of dry gas and/or coke is reduced. Specifically, compared with the single use of the industrial cracking catalyst, when the weight ratio of the metal trapping agent provided by the invention to the industrial cracking catalyst is 3: 97, the heavy oil yield is preferably reduced from 12.45 wt% to 9.21 wt%, the total liquid product yield is increased from 68.76 wt% to 75.35 wt%, the coke selectivity is reduced from 15.11% to 12.28%, and the dry gas selectivity is reduced from 4.83% to 3.00% when the catalyst mixture has a Ni content of about 4000ppm and a vanadium content of 5000 ppm. It can be seen that the metal collector provided by the invention can more effectively convert heavy oil into high-value products.

And compared with the prior art, compared with the conventional metal collector (the bulk density is usually more than 0.85 g/cm)³) Compared with the prior art, the collector of the technology provided by the invention has relatively reduced bulk density, which is beneficial to relatively reducing the production cost of the metal collector.

Drawings

FIG. 1 is an Al nuclear magnetic comparison of a magnesium aluminum sol used in accordance with the present invention with a magnesium aluminum sol of CN 1445167A;

fig. 2 is an XRD comparison spectrum of the metal trap according to example 1 of the present invention and that prepared according to comparative example 1.

Detailed Description

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

In a first aspect, the invention provides a metal trapping agent, which comprises magnesium oxide and aluminum oxide, wherein at least part of the magnesium oxide and at least part of the aluminum oxide form a magnesium-aluminum spinel structure, and the content of the magnesium oxide is more than 38 wt% based on 100% of the total weight of the metal trapping agent; the metal collector has a bulk density of less than 0.85g/cm³The abrasion index is below 2%/h.

The metal trapping agent according to the present invention, preferably, the content of the magnesium oxide is 40 to 60% by weight based on 100% by weight of the total weight of the metal trapping agent; the bulk density of the metal trapping agent is 0.75-0.84g/cm³The abrasion index is 0.8 to 1.5%/h, preferably the abrasion index is 1.6%/h or less.

In the present invention, the bulk density is measured by the RIPP standard method (see "analytical methods in petrochemical industry (RIPP methods of experiments)", ed. Yang Cui et al, ed. by scientific Press, 1990).

The metal collector according to the present invention may contain only magnesia and alumina, and may further contain a third component according to the use requirement, and in this case, it is preferable that the magnesia content satisfies the above requirements and the alumina content is 20 to 60% by weight based on 100% by weight of the total weight of the metal collector.

According to the metal collector of the present invention, in order to optimize the action and effect of the metal collector, it is preferable that the metal collector further comprises phosphorus pentoxide (as a third component), and the content of phosphorus pentoxide is preferably 0.001 to 30% by weight, preferably 1 to 10% by weight, based on 100% by weight of the total weight of the metal collector.

According to the metal trapping agent of the present invention, in order to optimize the action effect of the metal trapping agent, it is preferable that the metal trapping agent further comprises a rare earth oxide (as a third component), preferably, the content of the rare earth oxide is 0.001 to 1 wt% based on 100% of the total weight of the metal trapping agent, and preferably, the rare earth element in the rare earth oxide is one or more selected from La, Ce, Sc, Pr and Nd. The rare earth oxide is attached to the magnesium-aluminum sol introduced in the process of preparing the metal trapping agent, and the addition of the rare earth oxide in the magnesium-aluminum sol is favorable for forming ultrafine rare earth colloidal composite precipitate which has certain reaction activity and equivalent bonding property.

In order to further reduce the wear index of the metal collector, it is preferable that the metal collector further comprises clay (as a third component), preferably the clay is contained in an amount of 0.001 to 30% by weight, preferably 5 to 20% by weight, based on 100% by weight of the total weight of the metal collector.

According to the present invention, wherein the clay used is a clay raw material well known to those skilled in the art, commonly used clay species may be used in the present invention, and for the present invention, it is preferable that the clay is one or more of kaolin, halloysite, montmorillonite, diatomaceous earth, halloysite, pseudohalloysite, saponite, rectorite, sepiolite, attapulgite, hydrotalcite and bentonite. Wherein, the sepiolite is a magnesium-rich fibrous silicate clay mineral, and in the structural unit, silicon-oxygen tetrahedron and magnesium-oxygen octahedron are mutually alternated, and have the transitional structural characteristics of layer shape and chain shape. The acid modified sepiolite is used as the FCC catalyst substrate, so that the specific surface area, the pore volume and the mesopore pore volume of the catalyst can be effectively improved, and the heavy metal resistant effect of the catalyst can be enhanced. The kaolinite and the quasi-halloysite have the properties which are relatively similar to each other, the halloysite has the characteristics of large specific surface area, large pore volume, small pore size distribution, few macropores and more mesopores, and the halloysite also has the characteristics of large surface acidity, high micro-activity index, good pore structure stability and the like. For the present invention, preferably the clay is one or more of sepiolite, kaolin and halloysite.

The method for producing the metal trapping agent of the present invention can be produced by various methods, and the inventors of the present invention have found that the metal trapping agent having a bulk density within the range of the present invention produced by the production method of the present invention described below has a better metal trapping effect than the metal trapping agent having the bulk density within the range of the present invention produced by other production methods.

In a second aspect, the present invention also provides a method for producing a metal trapping agent, the method comprising: mixing a first aluminum source, magnesium-aluminum sol, a magnesium source, optional clay, optional acid and an optional solvent to prepare mixed slurry, drying and roasting to obtain the metal trapping agent; wherein, Mg in the magnesium aluminum sol: the molar ratio of Al is (1.5-6): (1-2), preferably (4-6): 1, and the ratio of Al in the magnesium aluminum sol: the mol ratio of Cl is (1-1.5): 1.

the metal collector prepared by the preparation method provided by the invention has the advantages that the content of magnesium oxide, the bulk density and the abrasion index are in the ranges, and the metal collector has high liquid product yield and reduced dry gas and/or coke yield when being used for heavy oil catalytic cracking with high metal (such as vanadium).

According to the present invention, it is preferable that the method for producing the metal trapping agent comprises the steps of: s1, mixing a first aluminum source, optionally clay, optionally acid, and a solvent to prepare a first slurry; s2, mixing the first slurry and the magnesium-aluminum sol to prepare a second slurry; and S3, mixing the second slurry and a magnesium source to prepare the mixed slurry.

According to the present invention, preferably, the magnesium oxide is present in an amount of more than 38 wt%, preferably 40 to 60 wt%, preferably 20 to 60 wt%, preferably 0.001 to 30 wt%, more preferably 5 to 20 wt%, based on 100 wt% of the third slurry on a dry basis (dry weight without solvent).

According to the invention, in the step S1, acid is reasonably added according to the selection of the first aluminum source, so as to achieve an acidification effect on the first aluminum source and achieve a certain binding property; this treatment tends to make the slurry more acidic, and if a basic magnesium source is added directly to the first slurry, it may cause a violent reaction, which is not favorable for the formation of spinel components, and may cause coagulation due to an excessively high reaction rate; according to the method, preferably, before the magnesium source is added, the magnesium-aluminum sol is added, so that certain acidity of the first slurry is favorably neutralized, the difference of the pH value between the magnesium source and the first slurry is reduced, the reaction speed is slowed down, the production of a spinel component is promoted, the possibility of occurrence of a condensation phenomenon is reduced, the viscosity of the whole colloid is reduced under the condition of increasing the bonding performance of the binder, the fluidity of the colloid is increased, and the forming of the metal collector is favorably realized.

According to the invention, the purpose of the invention can be achieved according to the technical scheme, the selectable range of the conditions of the mixed pulping in the steps S1, S2 and S3 is wide, for example, the reaction time of the steps S1 and S2 can be more than 15min, preferably 15-60min under the condition that the temperature is 0-50 ℃, preferably 15-40 ℃; for example, the reaction temperature in S3 may be 0 to 50 ℃, preferably 15 to 35 ℃; the reaction time is 15min or more, preferably 15 to 60 min.

According to the invention, the object of the invention can be achieved according to the technical scheme, and the first aluminum source and the magnesium-aluminum sol (see the subsequent definition) have wide selectable range. Preferably, the weight ratio of the magnesium aluminum sol to the aluminum source is (0.5-2.5): 1.

according to the invention, the object of the invention can be achieved according to the technical scheme, and the first aluminum source and the magnesium-aluminum sol (see the subsequent definition) have wide selectable range. Preferably, the weight ratio of the magnesium source in terms of magnesium oxide to the magnesium aluminum sol in terms of aluminum oxide is (0.15-2): 1.

according to the present invention, the variety of the magnesium source can be widely selected, and any water-soluble magnesium source conventionally used in the art can be used in the present invention, and preferably, the magnesium source is one or more selected from magnesium oxide, magnesium nitrate, magnesium sulfate and magnesium phosphate; preferably, the magnesium source is light magnesium oxide, the particle size D50 of the light magnesium oxide is less than or equal to 4 mu m, and the particle size D90 of the light magnesium oxide is less than or equal to 10 mu m; in the present invention, D50 and D90 are both mass-weighted average particle diameters.

According to the present invention, the first aluminum source may be selected from a wide variety of types, and the first aluminum source that is conventionally used in the art and is peptized by an acid may be used in the present invention, and preferably, the first aluminum source is one or more selected from gibbsite, surge, nordstrandite, diaspore, boehmite, pseudo-boehmite, rho-alumina, chi-alumina, eta-alumina, gamma-alumina, kappa-alumina, delta-alumina, and theta-alumina, wherein the first aluminum source is preferably pseudo-boehmite.

The clay is one or more selected from kaolin, halloysite, montmorillonite, diatomite, halloysite, pseudohalloysite, saponite, rectorite, sepiolite, attapulgite, hydrotalcite and bentonite;

the acid is one or more selected from hydrochloric acid, sulfuric acid, phosphoric acid and oxalic acid;

the solvent is selected from deionized water and/or decationized water.

According to the present invention, the metal collector prepared further contains phosphorus pentoxide, and in this case, in S3 of the preparation method, after the second slurry and the magnesium source are mixed, the method further comprises the step of adding an alkaline or neutral phosphorus salt to the slurry, preferably in an amount of 0.001 to 30% by weight, more preferably 1 to 10% by weight, based on 100% by weight of the second slurry on a dry basis, based on the phosphorus pentoxide;

according to the present invention, the basic or neutral phosphorus salt is not particularly limited as long as it can be dissolved in a solvent and the PH of the solution after dissolution is basic or neutral. The additional alkaline or neutral phosphorus salt which can be selected in the invention is one or more selected from potassium phosphate, sodium phosphate, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, ammonium phosphate and urea containing phosphorus.

According to the present invention, the object of the present invention can be achieved according to the above technical solution, in the step of adding alkaline or neutral phosphorus salt to the slurry and mixing in S3, the mixing conditions are widely selected and may be conventional mixing conditions, and preferably, the mixing conditions in this step include: 10-50 deg.C for 2-20 min.

According to the invention, the magnesium-aluminum sol is preferably obtained by mixing a magnesium-containing compound and an aluminum sol; the pH value of the magnesium-aluminum sol is 2.5-4.5;

according to the present invention, the magnesium aluminum sol may preferably further contain phosphorus pentoxide and/or rare earth oxide. In a preferred embodiment of the present invention, the rare earth oxide is RE in the magnesium-aluminum sol₂O₃Metering Al in the magnesium aluminum sol₂O₃(0.01-1.5): 1; preferably, the weight ratio is (0.01-0.8): 1. preferably, the rare earth oxide may be an oxide of at least one of La, Ce, Sc, Pr, and Nd. In a preferred embodiment of the present invention, P is in the magnesium-aluminum sol₂O₅With Al in the magnesium-aluminum sol₂O₃In a weight ratio of＝(0.01～1)：1。

According to the invention, preferably, the magnesium-aluminum sol is prepared by stirring a magnesium-containing compound and aluminum sol at 50-90 ℃ for 2-4 h for (once) mixing; wherein the feeding molar ratio of the magnesium-containing compound (Mg) to the aluminum sol (Al) is (1-2): (2-5), wherein the molar ratio of the total amount of Cl contained in the magnesium-containing compound and the aluminum sol to Al in the aluminum sol is 1: (1-1.5).

According to the invention, the preparation method of the magnesium aluminum sol preferably further comprises the following steps: mixing (secondarily) a mixed product (i.e., a primary mixed product) of a magnesium-containing compound and an alumina sol with a phosphorus compound and/or a rare earth compound; preferably, the temperature of the (secondary) mixing is 30-60 ℃ and the time is 0.5-2 h.

In the method for preparing the magnesium-aluminum sol, stirring is carried out during the primary mixing and the secondary mixing, and the stirring is stopped, namely the first mixing and the second mixing are finished. The time of the primary mixing and the secondary mixing described below is a time when stirring is continued.

In the preparation method of the magnesium-aluminum sol, preferably, the product obtained by the primary mixing is kept still for 0.5-1.5 hours at normal temperature before the secondary mixing. The standing refers to a state in which a product obtained by the primary mixing is left without stirring after the stirring accompanying the primary mixing is stopped.

Wherein the rare earth compound is represented by RE₂O₃Counting the product obtained by the first mixing as Al₂O₃The weight ratio is (0.01-1.5): 1; more preferably RE₂O₃：Al₂O₃(0.01-0.8): 1; the rare earth element in the rare earth compound is cerium or a mixture of cerium and other rare earth elements; preferably, the other rare earth elements are one or more selected from lanthanide series and series rare earth elements, preferably La and at least one of Sc, Pr and Nd.

In the preparation method of the magnesium aluminum sol, the phosphorus compound is selected from one or more of phosphorus pentoxide, phosphoric acid and phosphate; said phosphatingCompound P₂O₅Counting the product obtained by the first mixing as Al₂O₃The weight ratio is (0.01-1): 1.

according to the present invention, preferably, the magnesium-containing compound is a magnesium salt or magnesium oxide. The magnesium salt may be an inorganic salt of magnesium, such as at least one of magnesium chloride, magnesium sulfate, magnesium nitrate, and magnesium phosphate. The magnesium oxide is preferably light magnesium oxide, i.e. has an MgO content of more than 96% by weight, SiO₂Magnesium oxide with a content of less than 0.5% by weight and a content of CaO of less than 1% by weight.

According to a preferred embodiment of the invention, the selected aluminum sol has the advantages of less free chloride ions, optimized structure, high viscosity, low corrosion rate, high pH value and the like. Preferably, the molar ratio of aluminum to chlorine in the aluminum sol is (1-1.5): 1, corrosion rate is not more than 1.5g/m²H, a pH of 2.8 or more and a viscosity of 500 mPas or more.

According to the invention, the aluminum-chlorine molar ratio of the aluminum sol is preferably (1.35-1.5): 1.

according to the invention, the aluminum sol preferably contains 11.5-13% of aluminum element by weight.

According to the invention, the aluminium sol preferably has a density of 1.31g/cm³～1.35g/cm³。

According to the invention, the viscosity of the aluminium sol is preferably between 500 and 10000 mPas.

According to the present invention, it is preferable that the viscosity of the alumina sol provided by the present invention at 20 ℃ is 500 mPas or more, for example, 500 mPas to 10000 mPas, and the density is 1.31g/cm³～1.35g/cm³。

According to the invention, the corrosion rate of the aluminium sol is preferably 1g/m²·h～1.5g/m²·h。

According to the present invention, the pH of the alumina sol is preferably 2.8 to 3.5.

In the invention, free chloride ions in the aluminum sol can be measured by a sedimentation method, for example, ammonia water is used for adjusting the pH value of the aluminum sol to be 5-6, the aluminum sol is flocculent and precipitated, the precipitate is separated, the content of chloride ions in supernatant liquid is measured, and the content of free chloride ions in the aluminum sol is determined.

In the present invention, the density of the aluminum sol is a density at 20 ℃ and is measured by a glass densitometer.

In the present invention, the viscosity of the aluminum sol is a viscosity at 20 ℃ and is measured by a rotational viscometer.

In the invention, the corrosion rate of the aluminum sol can be measured by a method of a hanging piece experiment.

In the invention, the element content in the aluminum sol is measured by an XRF fluorescence method.

In the present invention, the reaction can be carried out by using an aluminum sol²⁷And (4) observing the structure optimization of the aluminum sol by using an Al nuclear magnetic spectrum. Preparation of the aluminum Sol of the invention (preparation example 1) described below²⁷In an Al nuclear magnetic spectrum, as shown in FIG. 1 (marked as A1), the peak height and the peak area of a signal peak appearing at a chemical shift of 0-3 are small, which indicates that the quantity of the monomeric aluminum is small; the peak height and the peak area of a signal peak appearing at the chemical shift of 60-63 are large, which indicates that the high polymeric aluminum is much.²⁷The result of Al nuclear magnetic spectrum shows that the aluminum sol of the invention is a structure mainly comprising high-polymerization aluminum. The alumina sol obtained in the prior art (example method of CN 1445167A) (marked as DA1 in fig. 1) was measured in the same manner, but the peak height and peak area of the signal peak with chemical shift of 0 to 3 were large, and the peak height and peak area of the signal peak with chemical shift of 60 to 63 were small, indicating that the alumina sol in the prior art is mainly composed of monomeric aluminum.

Preferably, the aluminum sol is prepared by²⁷In the Al nuclear magnetic spectrogram, the ratio of the peak area with chemical shift of 60-63 to the peak area with chemical shift of 0-3 is more than 1; preferably, the ratio of the peak area with a chemical shift of 60 to 63 to the peak area with a chemical shift of 0 to 3 is 1 to 1.6, for example 1.1, 1.2, 1.3, 1.4 or 1.5. Therefore, the content ratio of the high polymeric aluminum to the mono-polyaluminium in the alumina sol indirectly embodies the invention is more than 1, and the preferable ratio is 1-1.5.

According to the present invention, preferably, the preparation of the aluminum sol comprises: (1) first contacting metallic aluminum with hydrochloric acid; (2) carrying out second contact on the mixture after the first contact and a second aluminum source; the temperature of the first contact is 20-30 ℃ higher than that of the second contact.

The method for preparing the aluminum sol used for preparing the magnesium aluminum sol has simple working procedures and easily controlled conditions, can prepare the aluminum sol at a lower temperature, and the prepared aluminum sol has the advantages of less free chloride ions, optimized structure, large viscosity, small corrosion rate, high pH value and the like.

The method for preparing the aluminum sol reduces the use amount of hydrochloric acid, reduces the addition amount of chloride ions, reduces the damage of free acid to the properties of the aluminum sol, improves the activity of the aluminum sol, and avoids the defects that the pH value of the aluminum sol is too low, so that a molecular sieve is damaged, and the activity of a catalyst is influenced due to excessive hydrochloric acid. Meanwhile, the method for preparing the aluminum sol can use the inorganic aluminum compound to replace part of metallic aluminum, thereby obviously reducing the production cost of the aluminum sol.

In the method for producing an aluminum sol of the present invention, stirring is carried out while the first contact and the second contact are carried out, and the stirring is stopped, that is, the first contact and the second contact are completed. The time of the first contact and the second contact described below is a time when stirring is continued.

According to the present invention, in the method for preparing the aluminum sol, the temperature of the first contact is preferably 50 to 80 ℃.

According to the present invention, in the method for preparing the aluminum sol, the temperature of the second contact is preferably 20 to 50 ℃.

According to the present invention, in the method for preparing an aluminum sol, the molar ratio of the amount of the metallic aluminum in the step (1) to the amount of the second aluminum source in the step (2) is preferably (5-10): 1, calculated as Al.

According to a preferred embodiment of the present invention, the method of preparing an aluminum sol further comprises: and (3) before the step (2), standing the mixture after the first contact at normal temperature for 1-30 h, preferably standing for 2-6 h. The standing means that the mixture after the first contact is left without stirring after the stirring accompanying the first contact is stopped.

The method for preparing the aluminum sol according to the invention has a normal temperature of, for example, 0 to 40 ℃.

According to a preferred embodiment of the present invention for preparing the aluminum sol, the conditions of the first contacting further comprise: the amount of the metallic aluminum is 0.8mol to 1.3mol relative to 1mol of hydrochloric acid.

According to a preferred embodiment of the present invention for preparing the aluminum sol, the conditions of the first contacting further comprise: the first contact time is 2-5 h.

According to a preferred embodiment of the present invention for preparing the aluminum sol, the conditions of the first contacting further comprise: the concentration of hydrochloric acid is 31 to 36 wt%.

According to a preferred embodiment of the present invention for preparing the aluminum sol, the second contacting conditions further comprise: the second contact time is 3-4 h.

According to a preferred embodiment of the present invention for preparing the aluminium sol, said second aluminium source in the second contacting is preferably metallic aluminium and/or an inorganic aluminium compound.

In the preparation process of the alumina sol of the present invention, the optional range of the kind of the inorganic aluminum compound is wide, and for the present invention, it is preferable that the inorganic aluminum compound is one or more of aluminum chloride, aluminum oxide, aluminum hydroxide and soft aluminum; more preferably, the inorganic aluminum compound is Al₂O₃More preferably gamma-Al₂O₃And/or eta-Al₂O₃。

According to the present invention, the phosphorus pentoxide and/or the rare earth oxide contained in the magnesium-aluminum sol may be added during the preparation of the magnesium-aluminum sol or may be added during the preparation of the aluminum sol. In a preferred mode, the method for preparing the aluminum sol further comprises a third contact of the mixture obtained by the second contact with a phosphorus compound and/or a rare earth compound.

In the method for producing the aluminum sol according to the present invention, the conditions for contacting the mixture obtained by the second contacting with the rare earth compound are wide in selectable ranges, and for the present invention, it is preferable to include: the third contact temperature is 10-50 ℃, and the third contact time is more than 10min preferably; preferably, the third contact time is 10 to 60 min.

According to the present invention, in the method for preparing the alumina sol, the kinds of the rare earth compounds can be selected widely, and the kinds of the rare earth compounds well known in the art can be used in the present invention, and for the present invention, cerium or a mixture of cerium and other rare earth elements is preferred; preferably, the other rare earth elements are one or more selected from lanthanide series and series rare earth elements, preferably lanthanum or a mixture of lanthanide series rare earth elements (including La and at least one of Sc, Pr and Nd) with lanthanum content of more than 50 wt%.

In the preparation of the alumina sol according to the present invention, preferably, the rare earth compound is RE₂O₃The mixture obtained by the second contact is counted as Al₂O₃The weight ratio is (0.01-1.5): 1; more preferably, the weight ratio is (0.01 to 0.8): 1.

according to a preferred embodiment of the preparation of the aluminium sol according to the present invention, the phosphorus compound may be a starting material well known to the person skilled in the art, and for the purposes of the present invention, it is preferably selected from one or more of phosphorus pentoxide, phosphoric acid and a phosphate salt, more preferably the phosphorus compound is present as P₂O₅The mixture obtained by the second contact is counted as Al₂O₃The weight ratio is (0.01-1): 1.

the method for preparing the aluminum sol in the present invention can be continuously performed.

According to the present invention, the second slurry formed is preferably dried by means of spray drying under conditions conventional in the art, such as an inlet temperature of 650 ℃ and an outlet temperature of 180 ℃; in addition, the obtained particles are preferably subjected to roasting treatment after spray drying, wherein the roasting temperature is 200-650 ℃, and the roasting time is 0.5-2 h.

According to the invention, the technical collectors are the equipment commonly used by the person skilled in the art in the preparation, gelling, spray drying, washing, pneumatic drying and the like.

The invention provides a metal trapping agent prepared according to the preparation method of the invention.The metal collector prepared by the preparation method provided by the invention has the advantages of relatively increased content of magnesium oxide, relatively reduced bulk density, lower ball milling index and the like, and preferably, the metal collector prepared by the preparation method provided by the invention contains magnesium oxide and aluminum oxide, at least part of the magnesium oxide and at least part of the aluminum oxide form a magnesium aluminate spinel structure, and the content of the magnesium oxide is more than 38 wt% based on 100% of the total weight of the metal collector; the metal collector has a bulk density of less than 0.85g/cm³The abrasion index is below 2%/h.

The invention provides application of the metal collector in catalytic cracking.

The metal collector of the present invention is suitably used in catalytic cracking reactors such as fluidized beds, fixed beds, transport beds, and slurry beds, and preferably used in fluidized beds.

The metal trapping agent provided by the invention has the same wear index and particle size distribution with a catalytic cracking catalyst, and preferably has the bulk density slightly higher than that of the catalytic cracking catalyst.

The metal trapping agent provided by the invention has a good metal trapping effect, for example, when the metal trapping agent provided by the invention is used for high-vanadium heavy oil catalytic cracking, the damage of vanadium to a cracking catalyst can be relieved, the yield of liquid products is improved, and the yield of dry gas and/or coke is reduced. Specifically, compared with the single use of the industrial cracking catalyst, when the weight ratio of the metal trapping agent provided by the invention to the industrial cracking catalyst is 3: 97 combined, the heavy oil yield decreased from 12.45 wt% to 9.21 wt%, the total liquid product yield increased from 68.76 wt% to 75.35 wt%, the coke selectivity decreased from 15.11% to 12.28%, and the dry gas selectivity decreased from 4.83% to 3.00% when the Ni content on the catalyst mixture was about 4000ppm and the vanadium content was 5000 ppm. It can be seen that the metal collector provided by the invention can more effectively convert heavy oil into high-value products.

The invention provides a catalytic cracking method, which comprises the following steps: under the catalytic cracking condition, heavy oil raw material is contacted with a catalyst mixture containing a metal collector and a catalytic cracking catalyst, wherein the metal collector is the metal collector disclosed by the invention.

According to the catalytic cracking method of the present invention, the weight ratio of the metal collector to the catalytic cracking catalyst in the catalyst mixture is preferably 1: 10-99, preferably 1: 30-99, more preferably 1: 50 to 99, particularly preferably 1: 70 to 99, particularly preferably 1: 90 to 99, particularly preferably 1: 95-99.

According to the catalytic cracking process of the present invention, it is preferred that the bulk density of the metal collector is higher than that of the catalytic cracking catalyst, and it is more preferred that the difference between the bulk densities of the metal collector and the catalytic cracking catalyst is 0.03 to 0.15g/cm³Preferably 0.05 to 0.1g/cm³. It is presumed that when the bulk density of the metal collector is larger than that of the catalytic cracking catalyst, the metal collector and the catalytic cracking catalyst from the regenerator can be brought into contact with the raw oil (e.g., vanadium-containing raw oil) preferentially to the catalytic cracking catalyst during use, thereby facilitating collection of metal compounds, and thus the metal collecting ability can be improved.

According to the catalytic cracking process of the present invention, preferably the contacting is carried out in a fluidized bed reactor and/or a transport bed reactor for catalytic cracking reactions, and the heavy oil feedstock is fed from the bottom of the reactor. Thus, the high bulk density metal collector of the present invention can be preferably brought into contact with the heavy oil feedstock, thereby improving the metal collecting effect.

More preferably, according to the catalytic cracking process of the present invention, the catalytic cracking reactor is a fluidized bed reactor.

According to the catalytic cracking process of the present invention, the catalytic cracking conditions may be those commonly used in the art, and the present invention does not require any particular requirement and will not be described in detail herein. The following preparation examples, examples and application examples further illustrate the features of the present invention, but the contents of the present invention are not limited by the examples.

Preparation example:

for illustrating the aluminum sol, magnesium aluminum sol and the preparation method thereof employed in the present invention:

the test items and test methods referred to in the following preparation examples are as follows:

and (3) measuring the content of free chloride ions in the aluminum sol by a sedimentation method, adjusting the pH value of the aluminum sol to 5-6 by using ammonia water, separating out precipitates when the aluminum sol is flocculent, and measuring the content of the chloride ions in the supernatant.

The density of the alumina sol was measured by a glass densitometer (Shenzhen Shenxin Yi Experimental facilities, Ltd.).

The viscosity of the aluminum sol was measured by a rotary viscometer (Shanghai Provisions scientific instruments Co., Ltd., model NDJ-1 rotary viscometer).

The content of elements in the alumina sol was measured by XRF fluorescence analysis (RIPP 117-90 standard method (compiled by "petrochemical analysis method" (RIPP test method) Yangcui et al, published by scientific Press, 1990)).

The corrosion rate of the aluminum sol can be measured by a method of a hanging piece experiment:

experimental equipment: adopting a 20# carbon steel test piece (silver white) as a hanging piece (the size is 50mm multiplied by 25mm multiplied by 2mm), a constant-temperature water bath, a magnetic stirrer, a blower and absorbent cotton;

experimental drugs: anhydrous ethanol, hydrochloric acid (10 wt%), hexamethylenetetramine (0.5 wt%), 5N sodium hydroxide;

the experimental steps are as follows: firstly, cleaning a sample by using absolute ethyl alcohol to remove grease on the surface of the sample; then soaking in anhydrous ethanol for 5min, further defatting and dehydrating. And after the above work is finished, taking out the sample, placing the sample on filter paper, drying the sample by cold air, wrapping the sample by the filter paper, placing the sample in a drier for storage, weighing the sample after 24 hours, and recording the weight of the obtained scraping blade as W1. Suspending the hanging piece into 1L of alumina sol contained in a container, standing for 24 hours at 0-30 ℃, and then placing the container containing the hanging piece and the alumina sol in a constant-temperature water bath at the temperatureThe reaction time is 6h at 80 ℃. After the reaction is finished, cleaning and removing black corrosion products on the hanging piece by using a mixture of 10 weight percent hydrochloric acid and 0.5 weight percent hexamethylene tetramine (a preparation method of the mixture is that 10 weight percent hydrochloric acid and 0.5 weight percent hexamethylene tetramine are mixed to prepare a solution with the pH value of 5-7) until the black corrosion products are completely cleaned, the hanging piece is silvery white, and immediately immersing the cleaned hanging piece into a 5N sodium hydroxide solution for passivation for 1 min; taking out, soaking in clean absolute ethyl alcohol for 1min, wiping with filter paper, drying with cold air, wrapping with filter paper, storing in a dryer, weighing after 24h, and recording the obtained weight as W2; calculating the corrosion rate as the following formula, wherein the corrosion rate is delta W/(T multiplied by A); in the formula: weighing W1 before hanging the delta W-hanging piece-weighing W2 after taking out the hanging piece; t is the hanging time (6h) of the hanging piece; a is the area of the hanging piece (0.28 dm)²)。

Aluminium sol²⁷Nuclear magnetic measurement of Al: adding decationized water to dilute the aluminum sol to 1 wt% (Al)₂O₃Content) to prepare a solution sample; measured by means of a superconducting nuclear magnetic resonance apparatus of the type INOVA500, manufactured by Varian corporation, under test conditions comprising: resonance frequency 130 MHz: (²⁷Al), pulse program s2pul, spectral width 90090Hz, number of accumulations 800, delay time 1.0s, sampling time 0.5s, solvent D₂O, external standard NaAlO₂。

The specifications of the raw materials involved in the following preparation examples are as follows:

concentration of the rare earth oxide solution: 328.46g/L, containing La and Ce (La: Ce molar ratio is 1: 1), produced by Qilu division of China petrochemical catalyst, Inc.;

phosphorus compound: phosphoric acid at a concentration of 75% by weight, from the company Qilu, petrochemical catalyst, Inc., China;

light magnesium oxide: from Hebei Chenchen Taiding magnesium chemical Limited company, industrial grade, containing more than 98% by weight of magnesium oxide, with a particle size D50 of 4nm and D90 of 15 nm;

magnesium sulfate heptahydrate: from Hebei Chenchen Taiding Mg chemical Co., Ltd, the product is of industrial grade and contains 99 wt% of magnesium sulfate heptahydrate.

Preparation example 1

This preparation example illustrates the method for producing an aluminum sol of the present invention.

(1) Carrying out first contact on 1mol of metal aluminum (China aluminum industry Co.) and 1mol of (HCl) hydrochloric acid, controlling the temperature of the first contact process to be 50 ℃, controlling the first contact time to be 3h, and controlling the initial concentration of the used hydrochloric acid to be 32 wt%;

(2) standing the mixture after the first contact at the normal temperature of 20 ℃ for 6h, and then reacting with gamma-Al₂O₃(Shandong aluminum works) and eta-Al₂O₃(Shandong aluminum works) at a second contact temperature of 30 ℃ for 4h, based on aluminum, of gamma-Al₂O₃eta-Al calculated as aluminum₂O₃The molar ratio of the aluminum metal to the metal aluminum in the step (1) is 0.05: 0.05: 1. the physicochemical properties of the aluminum sol are shown in Table 1.

The aluminum sol (denoted as A1) was subjected to²⁷Performing Al nuclear magnetic measurement, wherein a spectrogram is shown in figure 1, wherein the peak height and the peak area of a signal peak with chemical shift of 0-3 are small, and the number of the monomeric aluminum is small; the signal peak with the chemical shift of 60-63 has high peak height and large peak area, which indicates that the high polymeric aluminum is much. The result shows that the aluminum sol is a structure mainly containing high-polymerization aluminum. And calculating the ratio of the peak area with the chemical shift of 60-63 to the peak area with the chemical shift of 0-3 to be 1.3.

Preparation example 2

(1) Carrying out first contact on 1.1mol of metal aluminum and 1mol of (HCl) hydrochloric acid, controlling the temperature of the first contact process to be 80 ℃ and the time to be 2h, wherein the concentration of the hydrochloric acid is 36 weight percent;

(2) standing the mixture after the first contact at the normal temperature of 30 ℃ for 2h, and then reacting with gamma-Al₂O₃And eta-Al₂O₃Carrying out second contact at 50 deg.C for 3 hr of gamma-Al₂O₃eta-Al calculated as aluminum₂O₃The molar ratio of the aluminum metal to the metal aluminum in the step (1) is 0.1: 0.06: 1. the physicochemical properties of the aluminum sol are shown in Table 1.

And calculating the ratio of the peak area with the chemical shift of 60-63 to the peak area with the chemical shift of 0-3 to be 1.1.

Preparation example 3

(1) Carrying out first contact on 1.1mol of metal aluminum and 1mol of (HCl) hydrochloric acid, controlling the temperature of the first contact process to be 60 ℃ and the time to be 5h, wherein the concentration of the hydrochloric acid is 31 weight percent;

(2) standing the mixture after the first contact at normal temperature of 10 ℃ for 4h, and then reacting with gamma-Al₂O₃、η-Al₂O₃Carrying out second contact at 35 deg.C for 3.5h, calculated as Al, of gamma-Al₂O₃eta-Al calculated as aluminum₂O₃The molar ratio of the aluminum metal to the metal aluminum in the step (1) is 0.12: 0.08: 1. the physicochemical properties of the aluminum sol are shown in Table 1.

And calculating the ratio of the peak area with the chemical shift of 60-63 to the peak area with the chemical shift of 0-3 to be 1.2.

Preparation example 4

An alumina sol was prepared according to the method of example 3, except that gamma-Al was used alone₂O₃As the aluminum source in the step (2), gamma-Al in terms of aluminum₂O₃The molar ratio to metallic aluminum was 0.2: 1.

the physicochemical properties of the aluminum sol are shown in Table 1.

Preparation example 5

An alumina sol was prepared as in example 4, except that metallic aluminum was used instead of γ -Al₂O₃As the aluminum source of step (2), the molar ratio of Al introduced in step (2) to Al introduced in step (1) was 0.2: 1.

the physicochemical properties of the aluminum sol are shown in Table 1.

Preparation example 6

An alumina sol was prepared as in example 3, except that the temperature of the first contact was 90 ℃ and the temperature of the second contact was 60 ℃.

The physicochemical properties of the aluminum sol are shown in Table 1.

Preparation example 7

The alumina sol prepared in example 1 (as Al)₂O₃Calculated as RE) and rare earth oxide solution₂O₃Sum of La and Ce), RE₂O₃：Al₂O₃0.8: 1, adding phosphoric acid solution (with P)₂O₅Meter), P)₂O₅：Al₂O₃0.8: 1, stirring for 0.5h at 40 ℃ for third contact, mixing and filtering to obtain a stable aluminum sol product.

The physicochemical properties of the aluminum sol are shown in Table 1.

And calculating the ratio of the peak area with the chemical shift of 60-63 to the peak area with the chemical shift of 0-3 to be 1.5.

Comparative preparation example 1

The alumina sol was prepared according to the example method of CN 1445167A.

Aluminum oxide and hydrochloric acid are mixed according to the molar ratio of Al₂O₃Putting HCl into a reaction kettle in a ratio of 1:3, controlling the reaction temperature to be 140 ℃, keeping the reaction temperature for 2 hours, preparing an aluminum chloride solution, continuously adding a dilute sulfuric acid solution in the reaction process, then adding supplemented metal aluminum into the reaction kettle for 4 times according to the content of aluminum in the needed aluminum sol, keeping the reaction at 1 atmosphere and the temperature of 80 ℃ for 40 hours, continuously stirring in the reaction process to obtain the aluminum sol, and obtaining the physicochemical property of the aluminum solThe properties are shown in Table 1.

The alumina sol (designated as DA1) was subjected to²⁷And (3) performing Al nuclear magnetic measurement, wherein a spectrogram is shown in a figure 1, wherein the peak height and the peak area of a signal peak with a chemical shift of 0-3 are large, which indicates that the quantity of the monomeric aluminum is small, and the peak height and the peak area of a signal peak with a chemical shift of 60-63 are small, which indicates that the amount of the monomeric aluminum is large. The result shows that the aluminum sol is mainly of single poly aluminum.

And calculating the ratio of the peak area with the chemical shift of 60-63 to the peak area with the chemical shift of 0-3 to be 0.6.

Comparative preparation example 2

To the alumina sol (as Al) prepared in comparative preparation example 1₂O₃Calculated by RE) is added into the rare earth oxide solution₂O₃Sum of La and Ce), RE₂O₃：Al₂O₃0.8: 1, stirring for 0.5h, mixing and filtering to obtain a stable aluminum sol product, wherein the physicochemical properties of the aluminum sol are shown in table 1.

And calculating the ratio of the peak area with the chemical shift of 60-63 to the peak area with the chemical shift of 0-3 to be 0.7.

Comparative preparation example 3

An aluminum sol was prepared according to CN1743267A, example 1.

Taking 6.5g of Al₂(OH)_2.9Cl_3.1The polyaluminum chloride of (1), which contains 29.0% by weight of Al₂O₃31.8% by weight of Cl was dissolved in 10mL of water, 1.3g of metallic aluminum having a purity of 99.5% by weight was added, and the mixture was reacted at 50 ℃ under 0.1MPa with stirring for 7.5 hours and then filtered to obtain 16.71g of an alumina sol.

The physicochemical properties of the aluminum sol are shown in Table 1.

And calculating the ratio of the peak area with the chemical shift of 60-63 to the peak area with the chemical shift of 0-3 to be 0.4.

Comparative preparation example 4

To the alumina sol prepared in comparative preparation example 3 (as Al)₂O₃Calculated by RE) is added into the rare earth oxide solution₂O₃Sum of La and Ce), RE₂O₃：Al₂O₃0.8: 1, stirring for 0.5h, mixing and filtering to obtain a stable aluminum sol product, wherein the physicochemical properties of the aluminum sol are shown in table 1.

And calculating the ratio of the peak area with the chemical shift of 60-63 to the peak area with the chemical shift of 0-3 to be 0.5.

TABLE 1 physicochemical Properties of the aluminum Sol

When the free chloride ion contents of the aluminum sols obtained in preparation examples 1 to 3 and comparative preparation examples 1 and 3 were measured, it was found that the free chloride ions of the aluminum sol prepared in example 1 were small, and the experimental results are shown in Table 2.

TABLE 2 Properties of the supernatant of the settled Aluminosol

Preparation example 8

This preparation example illustrates the method for producing the magnesium-aluminum sol of the present invention.

First mixing 46.08kg of the aluminum sol of preparation example 1 with 46.30kg of light magnesium oxide by stirring at 25 ℃ for 1 hour; obtaining the magnesium-aluminum sol.

Wherein, the content of magnesium oxide in the magnesium-aluminum sol is 49.1 weight percent, Mg: the molar ratio of Al is 6: 1, Al: the molar ratio of Cl is 1.35: 1, pH 4.12.

Preparation example 9

First mixing 46.08kg of the aluminum sol of preparation example 1 with 46.30kg of a magnesium sulfate heptahydrate solution at 25 ℃ for 1 hour with stirring;

the resulting first mixed product was mixed with 10.72kg of a phosphorus compound at 10 ℃ for 1 hour for a second mixing to obtain a magnesium aluminum sol.

Wherein, Mg in the magnesium-aluminum sol: the molar ratio of Al is 6: 1, Al:the molar ratio of Cl is 1.35: 1, P₂O₅：Al₂O₃The weight ratio of (1) to (0.8): 1, pH 3.69.

Preparation example 10

First mixing 46.08kg of the aluminum sol of preparation example 1 with 46.30kg of light magnesium oxide at 25 ℃ for 1 hour with stirring;

the obtained first mixed product is stirred with 8.03kg of rare earth oxide solution and 10.72kg of phosphorus compound for 1 hour at 10 ℃ for second mixing to obtain the magnesium-aluminum sol.

Wherein, Mg in the magnesium-aluminum sol: the molar ratio of Al is 6: 1, Al: the molar ratio of Cl is 1.35: 1, RE₂O₃：Al₂O₃The weight ratio of (1) to (0.8): 1, P₂O₅：Al₂O₃The weight ratio of (1) to (0.8): 1, pH 2.99.

Preparation example 11

First mixing 46.08kg of the aluminum sol of preparation example 7 with 50.16kg of light magnesium oxide at 25 ℃ for 1 hour under stirring to obtain a magnesium aluminum sol.

Wherein, the content of magnesium oxide in the magnesium-aluminum sol is 51.1 weight percent, Mg: the molar ratio of Al is 6: 1, Al: the molar ratio of Cl is 1.39: 1, pH 2.56.

Comparative preparation example 5

The procedure of preparation example 8 was followed except that "46.08 kg of the aluminum sol of comparative preparation example 1 was" substituted "for" 46.08kg of the aluminum sol of example 1 ".

The magnesium-aluminum sol obtained had a magnesium oxide content of 49.1 wt%, Mg: molar ratio of Al 5.64: 1, Al: the molar ratio of Cl is 1.25: 1, RE₂O₃：Al₂O₃The weight ratio of (1) to (0.8): 1, pH 2.31.

Comparative preparation example 6

The procedure of preparation example 8 was followed except that "46.08 kg of the aluminum sol of comparative preparation example 2 was" substituted "for" 46.08kg of the aluminum sol of example 1 ".

The magnesium-aluminum sol obtained had a magnesium oxide content of 49.1 wt%, Mg: the molar ratio of Al is 5.90: 1, Al: the molar ratio of Cl is 1.26: 1, RE₂O₃：Al₂O₃The weight ratio of (1) to (0.8): 1, pH 2.15.

Examples

To illustrate the technical collector of the present invention and the method for producing the same.

In the present invention, the weight on a dry basis means the weight after baking at about 800 ℃ for 1 hour.

In the invention, the solid content of the material refers to the weight ratio of the material after high-temperature roasting to the weight of the material before roasting, namely the solid content of the material is 100 percent to the water content of the material.

In the present invention, the catalyst-to-oil ratio refers to the mass ratio of the catalyst to the feedstock oil.

In the present invention, ppm is ppm by weight unless otherwise specified.

The following examples were subjected to X-ray powder diffraction phase composition analysis (XRD).

X-ray powder diffraction method: an experimental instrument: x-ray diffractometer model D5005, Siemens, germany; the experimental conditions are as follows: cu target, Ka radiation, solid detector, tube voltage 40kV, tube current 40 mA. Step scanning, step width of 0.02 degrees, preset time of 2s and scanning range of 5-70 degrees.

The raw materials and manufacturers used in the following examples are as follows:

light magnesium oxide: from Hebei chenchenchen Taiding magnesium chemical Limited company, industrial grade, containing 98% by weight of magnesium oxide;

pseudo-boehmite: industrial grade, solid content 68.47% by weight;

kaolin: the solid content was 85.34% by weight, as obtained from Suzhou Kaolin Clay Co.

Aluminum sol: industrial agents, manufactured by the Qilu division of the Chinese petrochemical catalyst Co., Ltd., solid content of 22 wt%;

magnesium chloride hexahydrate: the Shandong Weifang Huayu magnesium chloride factory product is industrial grade, and the solid content is more than 99.6 percent;

potassium phosphate: the product of Hubei ferry chemical company Limited, industrial grade, purity is 99.5%;

the chemical reagents used in the comparative examples and examples are not specifically noted, and are specified to be chemically pure.

Example 1

For illustrating the metal trapping agent of the present invention and the preparation method thereof:

adding 120 Kg of decationized water into a stirring kettle, adding 9.61Kg of Suzhou kaolin under stirring, stirring for 60min, adding 31.7 Kg of pseudo-boehmite, stirring for 30min, adding 7.5 Kg of hydrochloric acid aqueous solution with the concentration of 31 weight percent, uniformly stirring for 30min, continuously adding 104 Kg of magnesium-aluminum sol obtained in the preparation example 8 and 39.7 Kg of decationized water, pulping, stirring for 40min, continuously adding 8.26Kg of light magnesium oxide, pulping, stirring for 30min, continuously adding 9.38Kg of potassium phosphate, pulping, and stirring for 30min to obtain slurry with the solid content of 31 weight percent. The obtained slurry was spray-dried at an inlet temperature of 650 ℃ and a tail gas temperature of 180 ℃ and then calcined at 650 ℃ for 2 hours to obtain the desired metal collector S1.

As shown in FIG. 2, the XRD comparison spectra of the metal trapping agent S1 and the industrial metal vanadium supplement agent B1 (the product prepared by the method provided by the patent CN 201210420784.4) are shown in FIG. 2, and from FIG. 2, the magnesium aluminate spinel structure is formed in both the metal trapping agent S1 prepared in the invention and the industrial metal vanadium supplement agent, while the XRD diffraction peak value of the metal trapping agent S1 in the invention at 2 theta angles of 42 degrees and 62 degrees is higher, so that the magnesium aluminate spinel content formed in the metal trapping agent prepared in the invention is higher.

Examples 2 to 6 and comparative example 1

Illustrative and comparative illustrations the metal traps of the present invention and their preparation:

metal traps were prepared by the method of example 1 except that the amounts of each component were as shown in Table 3 on a dry basis of 100% by weight of the slurry, and the prepared metal traps were respectively designated as S2-S6 and D1.

Table 3.

Example 7

a metal trapping agent S-7 was prepared by the method of example 1 except that the magnesium aluminum sol prepared in preparation example 11 was used in place of the magnesium aluminum sol prepared in preparation example 8.

Example 8

a metal trapping agent S-8 was prepared by the method in example 1 except that the magnesium aluminum sol prepared in comparative preparation example 5 was used in place of the magnesium aluminum sol prepared in preparation example 8.

Example 9

a metal trapping agent S-9 was prepared by the method in example 1 except that the magnesium aluminum sol prepared in comparative preparation example 6 was used in place of the magnesium aluminum sol prepared in preparation example 8.

Comparative example 2

the metal collector was prepared by the method of example 1, except that the feeding order of the light magnesium oxide and the magnesium aluminum sol was changed, and the prepared metal collector was designated as S-9.

The physicochemical parameters of the metal collectors prepared in examples 1 to 9 and comparative examples 1 and 2 were tested:

(1) the composition contents of the metal capturing agents described in examples 1 to 9 and comparative examples 1 and 2 were measured according to the RIPP 117-90 standard method (compiled by "analytical methods in petrochemical industry" (RIPP test method) Yankee et al, published by scientific Press, 1990), and the measurement results are shown in Table 4.

(2) The total pore volume of the metal trapping agent was measured according to the RIPP151-90 standard method (see "analytical methods for petrochemical industry" (RIPP test method), Ed. Yang Cui, science publishers, 1990), and the measurement results are shown in Table 4.

(3) The apparent bulk density of the metal trapping agent was measured according to the RIPP151-90 standard method (see "analytical methods for petrochemical industry" (RIPP test method), Ed. Yang Cui, science publishers, 1990), and the measurement results are shown in Table 4.

(4) The specific surface area of the metal collector was measured according to the method of GB/T5816-1995 using an Autosorb-1 nitrogen desorption apparatus from Congta, USA, and the sample was degassed at 300 ℃ for 6 hours before the test, and the measurement results are shown in Table 4.

(5) The bulk density of the metal capturing agent was measured according to the RIPP standard method (see "analytical methods in petrochemical industry (RIPP test method)", eds., Yanggui, et al, published by scientific Press, 1990), and the measurement results are shown in Table 4.

Table 4.

As can be seen from Table 4, the metal trapping agent prepared by the method has a better abrasion index under the conditions of relatively high content of magnesium oxide and relatively low bulk density; the gel content is higher in the gelling process of preparing the metal trapping agent, thereby being beneficial to spray forming of the catalyst and reducing the cost.

Application examples 1 to 10

This application example is intended to illustrate the heavy metal contamination method in which the metal scavenger according to the present invention (the aforementioned S1-S10) is used in combination with an industrial cracking catalyst and the catalytic cracking performance of the metal scavenger of the present invention for catalytic cracking.

(1) In the following application examples, the catalytic cracking raw oil is Wu-MIG three-raw oil, and the properties of the catalytic cracking raw oil are shown in the following table:

wu-mix three-raw-material oil	Materialized data	Wu-mix three-raw-material oil	Materialized data
				Density (20 ℃ C.), g/cm³	0.9044	Distillation range, deg.C
Dioptric light (20 ℃ C.)	1.5217	Initial boiling point	-
				Viscosity (100 ℃ C.), mm²/s	9.96	5％	243
Freezing point, DEG C	40	10％	294
				Aniline point, deg.C	95.8	30％	316
C, weight%	85.98	50％	395
				H, weight%	12.86	70％	429
S, wt.%	0.55	90％	473
				N, weight%	0.18	Carbon residue, m%	3.0

(2) In the following application example, the industrial cracking catalyst involved is an industrial catalyst B (industrial brand RICC-5, bulk density of 0.76 g/cm) provided by Qilu Branch of China petrochemical catalyst, Inc³)；

(3) In the following application examples, the metal trap according to the invention (previously described S1-S10) was mixed with a commercial cracking catalyst B in proportions by dry weight to form a catalyst mixture and the formulated catalyst mixture was subjected to cyclic fouling (to deposit Ni and V) on a cyclic aging unit, the Ni, V content on the cyclically fouled catalyst mixture being shown in tables 5 and 6,

the step of circulating pollution comprises the following steps: after the catalyst mixture was introduced with heavy metals (Ni and V) by the michel impregnation method, the catalyst material after introduction of heavy metals was loaded into a D-100 apparatus (small fixed fluidized bed) and treated on the D-100 apparatus as follows:

(a) heating to 600 ℃ at a heating rate of 20 ℃/min in a nitrogen atmosphere;

(b) heating to 780 ℃ at the heating rate of 1.5 ℃/min, keeping the temperature at 780 ℃, and changing the treatment atmosphere according to the following steps in the constant temperature process;

(i) the mixture was treated in an atmosphere containing 40% by volume of nitrogen (containing 5% by volume of propylene) and 60% by volume of water vapor for 10 minutes,

(ii) treated in an atmosphere containing 40% by volume of nitrogen (pure nitrogen, no propylene), 60% by volume of water vapor for 10 minutes,

(iii) to contain 40% by volume of air (containing 4000ppm SO)₂) An atmosphere of 60% by volume of water vapor was treated for 10 minutes,

(iv) treating for 10 minutes in an atmosphere containing 40 vol% nitrogen and 60 vol% water vapor; then repeating the steps (i) - (iv) once more in the aforementioned order, and then repeating the step (i) to finish the cyclic contamination step;

then, the aging step is carried out: aging the circularly contaminated catalyst mixture at 800 ℃ for 8 hours in an atmosphere containing 100 vol% of water vapor;

the catalytic performance of the catalyst mixture after cyclic fouling-aging was then examined on an ACE unit, where the feedstock oil entered the reactor bottom in contact with the catalyst mixture, and the specific evaluation conditions and results are shown in tables 5 and 6.

Comparative application examples 1 to 4

The comparative application examples are intended to illustrate the heavy metal contamination process of the comparative catalyst mixtures and the catalytic cracking performance of the comparative metal collectors for catalytic cracking.

Metal contamination and catalytic cracking were carried out by the method of the foregoing application example except that the catalyst mixture used was industrial catalyst B alone, and industrial metal vanadium replenishing agent B1, metal capturing agent D1 provided in comparative example 1 or metal capturing agent D2 provided in comparative example 2, the catalyst mixture after physical mixing with industrial catalyst B in the weight ratio, the Ni, V contents on the contaminated catalyst mixture were shown in Table 5 or Table 6, and the evaluation conditions and results were shown in Table 5 or Table 6.

Among them, the preparation method of the industrial metal trapping agent B1 (see example 1 in patent CN 201210420784.4) is as follows:

(1) 280g of pseudo-boehmite (as Al)₂O₃Metering), adding hydrochloric acid after uniform dispersion into deionized water, and contacting for 30 minutes to obtain first slurry, wherein the solid content of the first slurry is 15 wt%, and the pH value is 1.2;

(2) adding deionized water dispersed MgO slurry (containing MgO640g), controlling the temperature at 55 ℃, and contacting for 60 minutes to obtain a second slurry, wherein the solid content of the second slurry is 28 weight percent, and the pH value is 9.8; carrying out spray drying molding on the second slurry to obtain solid microspheres, wherein the microspheres with the particle size of 0-149 micrometers account for 92 volume percent, the microspheres with the particle size of 0-40 micrometers account for 20 volume percent, and the Average Particle Size (APS) of the microspheres is 70 micrometers;

(3) at normal temperature (10-40 ℃), 920g of the solid microspheres are mixed with 0.35L of water-soluble magnesium source solution (MgCl)₂228g/L) for 10min, drying the contacted mixture at 120 ℃ for 4 hours, and then roasting at the roasting condition of 600 ℃/2 hours to obtain the metal collector B1. The bulk density of the industrial metal vanadium supplement B1 is tested to be 0.91g/cm³The abrasion index was 2.8%/h.

Table 5.

Table 6.

Wherein, the conversion rate is gasoline yield, liquefied gas yield, dry gas yield and coke yield

Total liquid yield is liquefied gas yield, gasoline yield and diesel oil yield

Coke selectivity-coke yield/conversion

Dry gas selectivity-dry gas yield/conversion

As can be seen from the data in tables 5 and 6, the addition of a small amount (3 wt%) of the metal trap provided by the present invention to the catalytic cracking catalyst can slow the destruction of the catalytic cracking catalyst by vanadium, increase the overall liquid product yield, and improve the selectivity to dry gas and/or coke.

The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.

Claims

1. The metal collector is characterized by comprising magnesium oxide and aluminum oxide, wherein at least part of the magnesium oxide and at least part of the aluminum oxide form a magnesium-aluminum spinel structure, and the content of the magnesium oxide is 40-60 wt% based on 100% of the total weight of the metal collector; the bulk density of the metal trapping agent is 0.75-0.84g/cm³The abrasion index is below 2%/h.

2. The metal trap of claim 1, wherein the alumina is present in an amount of 20 to 60 wt%, based on 100 wt% of the total weight of the metal trap.

3. The metal collector of claim 1, further comprising from 0.001 to 30 wt% of phosphorus pentoxide, based on 100% of the total weight of the metal collector.

4. The metal trapping agent according to claim 3, further comprising 1 to 10% by weight of phosphorus pentoxide, based on 100% by weight of the total metal trapping agent.

5. The metal trapping agent according to claim 1, further comprising 0.001 to 1% by weight of a rare earth oxide, based on 100% by weight of the total metal trapping agent.

6. The metal collector of claim 5, wherein the rare earth element in the rare earth oxide is selected from one or more of La, Ce, Sc, Pr and Nd.

7. The metal collector of claim 1, further comprising 0.001 to 30 wt% of a clay, based on 100 wt% of the total weight of the metal collector.

8. The metal trap of claim 7, further comprising 5 to 20 wt% clay, based on 100% of the total weight of the metal trap.

9. A method for producing a metal trapping agent, comprising: mixing an aluminum source, magnesium-aluminum sol, a magnesium source, optional clay, optional acid and a solvent to prepare mixed slurry, drying and roasting to obtain the metal trapping agent; wherein, Mg in the magnesium aluminum sol: the molar ratio of Al is (1.5-6): (1-2), wherein Al in the magnesium-aluminum sol: the mol ratio of Cl is (1-1.5): 1;

the content of magnesium oxide is 40-60 wt% based on 100 wt% of the mixed slurry on a dry basis.

10. The method of claim 9, wherein the ratio of Mg: the molar ratio of Al is (4-6): 1.

11. the method for preparing according to claim 9, wherein the step of formulating the mixed slurry comprises:

s1, mixing a first aluminum source, optionally clay, optionally acid, and a solvent to prepare a first slurry;

s2, mixing the first slurry and the magnesium-aluminum sol to prepare a second slurry;

and S3, mixing the second slurry and a magnesium source to prepare the mixed slurry.

12. The production method according to any one of claims 9 to 11, wherein the content of alumina is 20 to 60% by weight based on 100% by weight of the mixed slurry on a dry basis.

13. The production method according to any one of claims 9 to 11, wherein the clay is contained in an amount of 0.001 to 30% by weight based on 100% by weight on a dry basis of the mixed slurry.

14. The method according to claim 13, wherein the clay is contained in an amount of 5 to 20 wt% based on 100 wt% on a dry basis of the mixed slurry.

15. The production method according to any one of claims 9 to 11, wherein the weight ratio of the magnesium aluminum sol to the aluminum source based on the magnesium oxide is (0.5 to 2.5): 1.

16. the production method according to any one of claims 9 to 11, wherein the weight ratio of the magnesium source in terms of magnesium oxide to the magnesium aluminum sol in terms of aluminum oxide is (0.15-2): 1.

17. the method according to claim 11, wherein in the S3, after the second slurry and the magnesium source are mixed, the method further comprises a step of adding an alkaline or neutral phosphorus salt to the slurry.

18. The production method according to claim 17, wherein the basic or neutral phosphorus salt is used in an amount of 0.001 to 30% by weight in terms of phosphorus pentoxide based on 100% by weight on a dry basis of the mixed slurry.

19. The method of claim 18, wherein the alkaline or neutral phosphorus salt is present in an amount of 1 to 10 wt.% as phosphorus pentoxide, based on 100 wt.% on a dry basis of the mixed slurry.

20. The method of claim 17, wherein the alkaline or neutral phosphorus salt is selected from one or more of potassium phosphate, sodium phosphate, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, ammonium phosphate, and urea containing phosphorus.

21. The method according to any one of claims 9 to 11, wherein the magnesium-aluminum sol is obtained by mixing a magnesium-containing compound with an aluminum sol, and the pH of the magnesium-aluminum sol is 2.5 to 4.5.

22. The method according to claim 21, wherein the magnesium-aluminum sol is prepared by mixing the magnesium-containing compound and the aluminum sol at 50 to 90 ℃ for 2 to 4 hours under stirring.

23. The preparation method of claim 21, wherein the aluminum-chlorine molar ratio in the aluminum sol is (1-1.5): 1, corrosion rate is not more than 1.5g/m²H, a pH of 2.8 or more and a viscosity of 500 mPas or more.

24. The preparation method according to claim 23, wherein the aluminum sol contains 11.5 to 13% by weight of aluminum element; the corrosion rate of the aluminum sol is 1g/m²·h～1.5 g/m²H, pH value of 2.8-3.5, density of 1.31g/cm³～1.35 g/cm³The viscosity is 500 to 10000 mPas.

25. The method of claim 23, wherein the aluminum sol is prepared²⁷In the Al nuclear magnetic spectrogram, the ratio of the peak area with chemical shift of 60-63 to the peak area with chemical shift of 0-3 is more than 1.

26. The method of claim 25, wherein the aluminum sol is prepared²⁷In the Al nuclear magnetic spectrogram, the peak area with the chemical shift of 60-63 peaks and the chemical shift of 0-3 peaksThe ratio of peak areas of the peaks is 1-1.6.

27. The production method according to claim 21, wherein the production of the aluminum sol comprises: (1) first contacting metallic aluminum with hydrochloric acid; (2) carrying out second contact on the mixture after the first contact and a second aluminum source; the temperature of the first contact is 20-30 ℃ higher than that of the second contact.

28. The method of claim 27, wherein the first contacting temperature is 50 to 80 ℃; the temperature of the second contact is 20-50 ℃.

29. The method of claim 27, wherein the first contacting conditions further comprise: the dosage of the metal aluminum is 0.8-1.3 mol relative to 1mol of hydrochloric acid calculated by HCl, the first contact time is 2-5 h, and the concentration of the hydrochloric acid is 31-36 wt%.

30. The method of claim 27, wherein the second contacting conditions further comprise: the second contact time is 3-4 h, the second aluminum source is metallic aluminum and/or an inorganic aluminum compound, and the inorganic aluminum compound is one or more of aluminum chloride, aluminum oxide, aluminum hydroxide and soft aluminum.

31. The production method according to claim 30, wherein the inorganic aluminum compound is Al₂O₃。

32. The method of claim 31, wherein the inorganic aluminum compound is γ -Al₂O₃And/or eta-Al₂O₃。

33. The preparation method of claim 27, wherein the molar ratio of the amount of the metallic aluminum in the step (1) to the amount of the second aluminum source in the step (2) is (5-10): 1.

34. the method of preparing according to claim 27, wherein the method of preparing the aluminum sol further comprises: and (3) before the step (2), standing the mixture after the first contact at normal temperature for 1-30 h.

35. The method of preparing according to claim 34, wherein the method of preparing the aluminum sol further comprises: and (3) before the step (2), standing the mixture after the first contact at normal temperature for 2-6 h.

36. The method according to any one of claims 9 to 11, wherein the magnesium-aluminum sol further contains phosphorus pentoxide and/or a rare earth oxide.

37. The method of claim 36, wherein the rare earth oxide is RE in the magnesium aluminum sol₂O₃Metering Al in the magnesium aluminum sol₂O₃The weight ratio of = (0.01 to 1.5): 1; p₂O₅With Al in the magnesium-aluminum sol₂O₃The weight ratio of = (0.01 to 1): 1.

38. the method of claim 37, wherein the rare earth oxide is RE in the magnesium aluminum sol₂O₃Metering Al in the magnesium aluminum sol₂O₃The weight ratio of = (0.01 to 0.8): 1.

39. the production method according to claim 11, wherein,

the magnesium source is one or more selected from magnesium oxide, magnesium nitrate, magnesium sulfate and magnesium phosphate;

the first aluminum source is one or more selected from gibbsite, surge dawsonite, nordstrandite, diaspore, boehmite, pseudo-boehmite, rho-alumina, chi-alumina, eta-alumina, gamma-alumina, kappa-alumina, delta-alumina and theta-alumina;

the solvent is selected from deionized water and/or decationized water.

40. The production method according to claim 39, wherein the magnesium source is light magnesium oxide having a particle size D50 ≤ 4 μm and a particle size D90 ≤ 10 μm.

41. A metal trapping agent obtained by the production method according to any one of claims 9 to 40.

42. Use of a metal trap according to any one of claims 1 to 8 and 41 in catalytic cracking.

43. A catalytic cracking process, characterized in that the process comprises: contacting a heavy oil feedstock under catalytic cracking conditions with a mixture comprising a metal trap agent and a catalytic cracking catalyst, wherein the metal trap agent is as defined in any one of claims 1 to 8 and 41.

44. The catalytic cracking process of claim 43 wherein the weight ratio of the metal collector to the catalytic cracking catalyst is 1: 10-99.

45. The catalytic cracking process of claim 44 wherein the weight ratio of the metal trap to the catalytic cracking catalyst is 1: 30-99.

46. The catalytic cracking process of claim 45 wherein the weight ratio of the metal trap to the catalytic cracking catalyst is 1: 50-99.

47. The catalytic cracking process of claim 46 wherein the weight ratio of the metal trap to the catalytic cracking catalyst is 1: 70-99.

48. The catalytic cracking process of claim 47 wherein the weight ratio of the metal trap to the catalytic cracking catalyst is 1: 90-99.

49. The catalytic cracking process of claim 48 wherein the weight ratio of the metal trap to the catalytic cracking catalyst is 1: 95-99.