阅读说明：本技术 一种石蜡加氢催化剂及其制备方法 (Paraffin hydrogenation catalyst and preparation method thereof ) 是由 倪术荣 吴显军 王刚 徐伟池 葛冬梅 孙发民 夏恩冬 于春梅 李凤铉 李瑞峰 马 于 2020-04-26 设计创作，主要内容包括：本发明公开了一种石蜡加氢精制催化剂及其制备方法,涉及加氢精制催化剂及其制备方法,石蜡加氢精制催化剂由载体和负载于载体上的活性组分组成：载体由氧化铝组成；活性组分包括Ni和/或Mo和/或W,本发明通过引入络合剂分步浸渍来减弱活性金属与载体之间的相互作用,同时改善活性金属的分散性,本发明催化剂在处理具有高芳烃含量的石蜡、微晶蜡原料时,具有突出的效果。(The invention discloses a paraffin hydrofining catalyst and a preparation method thereof, and relates to a hydrofining catalyst and a preparation method thereof, wherein the paraffin hydrofining catalyst consists of a carrier and active components loaded on the carrier: the carrier consists of alumina; the active component comprises Ni and/or Mo and/or W, the invention weakens the interaction between the active metal and the carrier by introducing the complexing agent for stepwise impregnation, and simultaneously improves the dispersibility of the active metal, and the catalyst has outstanding effect when processing paraffin and microcrystalline wax raw materials with high aromatic content.)

1. A preparation method of a paraffin hydrofining catalyst, which comprises a carrier and an active component, is characterized by comprising the following steps:

step (1): extruding and forming an alumina precursor, and then drying and roasting to obtain an alumina carrier;

step (2): adding complexing agent into strong ammonia water, stirring until the complexing agent is completely dissolved; adding ammonium molybdate tetrahydrate and/or nickel nitrate hexahydrate and/or ammonium metatungstate into the solution, and stirring the solution until the ammonium molybdate tetrahydrate and/or the nickel nitrate hexahydrate and/or the ammonium metatungstate are completely dissolved; and finally adding strong ammonia water to a constant volume to obtain a mixed impregnation liquid, wherein the substances are added according to the mass ratio of a complexing agent: concentrated ammonia water: ammonium molybdate tetrahydrate: nickel nitrate hexahydrate: ammonium metatungstate is 0-10: 0-60: 0-10: 0-20: 20-40 parts of;

and (3): and (3) adding the alumina carrier prepared in the step (1) into the mixed impregnation liquid obtained in the step (2), drying and roasting to obtain the paraffin hydrofining catalyst with nickel and/or molybdenum as active components.

2. The method for preparing a paraffin hydrofinishing catalyst according to claim 1, characterized by further comprising the steps of:

preparing ammonium metatungstate and citric acid into a mixed aqueous solution, impregnating the mixed aqueous solution with the paraffin hydrofining catalyst, drying and roasting to obtain the paraffin hydrofining catalyst containing nickel and/or molybdenum and tungsten as active components.

3. The preparation method of the paraffin hydrofining catalyst according to claim 1, wherein the complexing agent in the step (1) is nitrilotriacetic acid or sodium nitrilotriacetic acid, the drying temperature is 100-120 ℃, and the roasting temperature is 500-650 ℃;

the drying temperature in the step (3) is 100-120 ℃, and the roasting temperature is 200-400 ℃.

4. The method for preparing a paraffin hydrofining catalyst according to claim 2, wherein the drying temperature is 100 to 120 ℃ and the calcination temperature is 500 to 650 ℃.

5. The method for preparing a catalyst for hydrorefining paraffin according to claim 1, wherein the alumina is amorphous aluminum hydroxide, boehmite, pseudo-boehmite, gibbsite, metazoite or nordstrandite.

6. Paraffin hydrogenationThe refined catalyst is characterized by being prepared by the preparation method of the paraffin hydrofining catalyst according to claim 2, wherein the carrier accounts for 60-80% and the active component accounts for 20-40% in percentage by weight of the catalyst, and the mass of the oxide is NiO: MoO₃:WO₃0-10: 0-20: 20 to 40.

7. A catalyst for hydrorefining paraffin, which is produced by the process for producing a catalyst for hydrorefining paraffin according to any one of claims 1 to 5, and which has a specific surface area of 120m³/g～270m³The volume of the pores is 0.30 ml/g-1.2 ml/g, and the diameter of the pores is 5 nm-20 nm.

Technical Field

The invention relates to a method for hydrofining petroleum wax.

Background

Paraffin and microcrystalline wax are important petroleum products and important raw materials for medicine, daily chemical industry and other fine chemical industries. The raw material for hydrorefining the paraffin and the microcrystalline wax is from vacuum distillate oil or deasphalted oil, and the paraffin raw material usually contains a small amount of harmful substances, such as certain aromatic compounds harmful to human bodies, certain colored and unstable components and the like. At present, the wax material refining method is mainly a hydrofining method.

The research on the hydrogenation reaction process of paraffin and microcrystalline wax shows that the hydrofining reaction is completed by two chemical reaction processes of desulfurization and denitrification and aromatic saturation, and the desulfurization and denitrification reaction is controlled by thermodynamics and needs higher temperature. The aromatics saturation reaction is controlled by both thermodynamics and kinetics, requiring relatively low temperatures. The high-pressure petrochemical hydrogenation device adopts a single catalyst, and simultaneously considers the high-temperature desulfurization nitrogen and the low-temperature aromatic hydrocarbon saturation performance, so that the performance of the catalyst is difficult to further improve.

According to the quality requirements of paraffin products, the main purpose of paraffin hydrofining is to remove 3, 4-benzopyrene and other condensed ring aromatic hydrocarbons (food wax requirements) and S, N, O and other heterocyclic compounds influencing color and light and heat stability in paraffin raw materials on the premise of not changing main indexes (such as oil content, melting point, penetration degree, viscosity and the like) of paraffin, and the normal paraffin wax is expected not to crack as much as possible so as to improve the color, smell and stability of paraffin.

CN 100579652C introduces a paraffin hydrofining catalyst and a preparation method and application thereof. With Cr0₃-Al₂0₃Is used as a carrier, and takes nickel as a main active metal component. The method has the advantages of simple preparation process and low raw material loss, but has the defect of low activity of the catalyst.

CN 100446856C discloses a petroleum wax hydrofining catalyst and a preparation method thereof, wherein a catalyst carrier is composed of alumina and fluorine: the active component comprises Ni element and is selected from MoO₃、W0₃Two or any one of them. The interaction between the carrier and the active component is weakened through carrier modification, the dispersion state and the interaction of the metal active component are improved, the utilization efficiency of the active component is improved, and the dispersion of the metal can be further improved.

CN 102485847B discloses a method for hydrorefining petroleum wax, wherein a hydrorefining catalyst, namely alumina, is used as a carrier, and active components are NiO and MoO₃、WO₃One or two of them, and the catalyst has bimodal pore structureHowever, the catalyst still needs to be further reduced in cost.

Disclosure of Invention

The invention aims to provide a preparation method of a petroleum wax hydrofining catalyst, which weakens the interaction between active metal and a carrier by introducing a complexing agent and improves the dispersibility of the active metal at the same time.

In order to achieve the above object, the present invention provides a preparation method of a paraffin hydrorefining catalyst, the catalyst comprises a carrier and an active component, and the preparation method comprises the following steps:

step (1): extruding and forming an alumina precursor, and then drying and roasting to obtain an alumina carrier;

step (2): adding complexing agent into strong ammonia water, stirring until the complexing agent is completely dissolved; adding ammonium molybdate tetrahydrate and/or nickel nitrate hexahydrate and/or ammonium metatungstate into the solution, and stirring the solution until the ammonium molybdate tetrahydrate and/or the nickel nitrate hexahydrate and/or the ammonium metatungstate are completely dissolved; and finally adding strong ammonia water to a constant volume to obtain a mixed impregnation liquid, wherein the substances are added according to the mass ratio of a complexing agent: concentrated ammonia water: ammonium molybdate tetrahydrate: nickel nitrate hexahydrate: ammonium metatungstate is 0-10: 0-60: 0-10: 0-20: 20-40 parts of;

and (3): and (3) adding the alumina carrier prepared in the step (1) into the mixed impregnation liquid obtained in the step (2), drying and roasting to obtain the paraffin hydrofining catalyst with nickel and/or molybdenum as active components.

The preparation method of the paraffin hydrofining catalyst of the invention also comprises the following steps: preparing ammonium metatungstate and citric acid into a mixed aqueous solution, impregnating the mixed aqueous solution with a paraffin hydrofining catalyst, drying and roasting to obtain the paraffin hydrofining catalyst containing nickel and/or molybdenum and tungsten as active components.

The preparation method of the paraffin hydrofining catalyst comprises the following steps of (1) using nitrilotriacetic acid or sodium nitrilotriacetic acid as a complexing agent, drying at 100-120 ℃ and roasting at 500-650 ℃; the drying temperature in the step (3) is 100-120 ℃, and the roasting temperature is 200-400 ℃.

The preparation method of the paraffin hydrofining catalyst provided by the invention has the advantages that the drying temperature is 100-120 ℃, and the roasting temperature is 500-650 ℃.

The preparation method of the paraffin hydrofining catalyst of the invention is that the alumina can be amorphous aluminum hydroxide, boehmite, pseudoboehmite, gibbsite, surge boehmite or nordstrandite.

The invention also provides a paraffin hydrofining catalyst which is prepared by adopting the preparation method of the paraffin hydrofining catalyst, wherein the carrier accounts for 60-80% and the active component accounts for 20-40% in percentage by weight of the catalyst, and NiO: MoO₃:WO₃0-10: 0-20: 20 to 40.

The paraffin hydrofining catalyst of the invention has a specific surface area of 120m³/g～270m³The volume of the pores is 0.30 ml/g-1.2 ml/g, and the diameter of the pores is 5 nm-20 nm.

The invention can also be detailed as follows:

the catalyst for hydrorefining paraffin and microcrystalline wax uses alumina as carrier and NiO and/or MoO as active component₃And/or WO₃. The specific surface area of the catalyst was 120m³/g～270m³The volume of the pores is 0.30 ml/g-1.2 ml/g, and the diameter of the pores is 5 nm-20 nm.

The preparation method of the catalyst for hydrorefining the paraffin and the microcrystalline wax comprises the following specific steps:

(1) adding an alumina precursor into the mixture to be extruded and molded, then drying the mixture at 100-120 ℃, and roasting the dried mixture at 600 ℃ to obtain an alumina carrier;

(2) preparation of nickel and/or molybdenum containing catalysts:

(a) weighing a certain amount of nitrilotriacetic acid (NTA) and placing the nitrilotriacetic acid (NTA) into a beaker, then adding a certain amount of strong ammonia water into the beaker, and stirring until the nitrilotriacetic acid (NTA) is completely dissolved;

(b) weighing a certain amount of ammonium molybdate tetrahydrate, placing the ammonium molybdate tetrahydrate in the beaker in the step (a), and stirring until the ammonium molybdate tetrahydrate is completely dissolved;

(c) weighing a certain amount of nickel nitrate hexahydrate, placing the nickel nitrate hexahydrate in the beaker in the step (b), stirring the nickel nitrate hexahydrate until the nickel nitrate hexahydrate is completely dissolved, and finally adding concentrated ammonia water to a constant volume.

(d) Taking Al prepared in the step (1)₂O₃And (3) adding the solution prepared in the step (2) into a carrier, impregnating, drying at 110 ℃, and then roasting at 300 ℃ to obtain the nickel and/or molybdenum-containing catalyst.

(3) Preparation of nickel-and/or molybdenum-and/or tungsten-containing catalysts:

and (3) preparing a certain amount of ammonium metatungstate and citric acid into an aqueous solution, impregnating the aqueous solution with the catalyst prepared in the step (2), drying the aqueous solution at 110 ℃, and roasting the dried aqueous solution at 600 ℃ to obtain the catalyst containing nickel and/or molybdenum and/or tungsten.

The hydrofining catalyst prepared by the invention is characterized in that: the method adopts a stepwise complexing impregnation method to realize high-dispersion uniform loading of active metal components, weakens the interaction between W metal and a carrier through citric acid complexing impregnation, promotes the reduction of W species and the generation of Ni-W-O active phase precursor state, reduces the vulcanization temperature of the W species, improves the vulcanization degree of W, and promotes WS with smaller size and proper stacking₂Forming crystal grains; NiO and MoO can be improved by introducing NTA through NTA complexing and impregnation₃The dispersion degree of the species on the surface of the alumina carrier improves the utilization rate of active metal. The catalyst has high hydrogenation activity.

The hydrofining catalyst of the invention can treat inferior paraffin and microcrystalline wax raw materials, especially raw materials with high aromatic hydrocarbon content. The paraffin produced by using the catalyst can reach the food-grade paraffin standard (GB 7189-94). The microcrystalline wax produced by the method can reach the standard of food-grade microcrystalline wax (SH/T0013-1999).

Detailed Description

The following examples and comparative examples are given to further illustrate the points of the present invention, but the present invention is not limited to only the following examples.

Example 1

(1)A1₂O₃Preparation of the support

Weighing 1000g of pseudo-boehmite powder, 30g of sesbania powder, 30g of catalpic acid and 700ml of 3-5 wt% of dilute nitric acid, uniformly kneading, extruding and forming by using a plodder, drying at 110 ℃, roasting at 600 ℃ in air to obtain Al₂O₃And (3) a carrier.

(2) Preparation of ca-1-a catalyst

(a) Taking a clean beaker, weighing 7.7g NTA, placing the NTA in the beaker, adding 35ml of strong ammonia water into the beaker, and stirring until the NTA is completely dissolved;

(b) weighing 8.8g of nickel nitrate hexahydrate in a beaker in the step (a), stirring until the nickel nitrate hexahydrate is completely dissolved, and finally adding concentrated ammonia water to the volume of 50 ml.

(c) Taking Al prepared in the step (1)₂O₃And (3) adding 70g of carrier into the solution prepared in the step (2) for impregnation, drying at 110 ℃, and then roasting at 300 ℃ to obtain the catalyst ca-1-a.

(3) Preparation of ca-1-f catalyst

Preparing an aqueous solution by using a certain amount of ammonium metatungstate and citric acid, wherein the concentration of WO3 is 70g/100ml, the concentration of citric acid is 10g/100ml, taking 50ml of the solution and the catalyst ca-1-a prepared in the step (2), impregnating, drying at 110 ℃, and then roasting at 600 ℃ to obtain the catalyst ca-1-f.

Example 2

(1)A1₂O₃The preparation of the support was identical to example 1.

(2) Preparation of ca-2-a catalyst

(a) Taking a clean beaker, weighing 7.7g NTA, placing the NTA in the beaker, adding 25ml of strong ammonia water into the beaker, and stirring until the NTA is completely dissolved;

(b) weighing 10.7g of ammonium molybdate tetrahydrate, placing the ammonium molybdate tetrahydrate in a beaker in the step (a), dropwise adding concentrated ammonia water to enable the volume of the solution to be 40ml, and stirring until the ammonium molybdate tetrahydrate is completely dissolved;

(c) weighing 8.8g of nickel nitrate hexahydrate, placing the nickel nitrate hexahydrate in the beaker in the step (b), stirring the mixture until the nickel nitrate hexahydrate is completely dissolved, and finally adding strong ammonia water to the volume of 50 ml;

(d) taking Al prepared in the step (1)₂O₃And (3) adding 70g of carrier into the solution prepared in the step (2) for impregnation, drying at 110 ℃, and then roasting at 300 ℃ to obtain the catalyst ca-2-a.

(3) Preparation of ca-2-f catalyst

Preparing an aqueous solution from a certain amount of ammonium metatungstate and citric acid, wherein WO₃The concentration is 57g/100ml, the citric acid concentration is 10g/100ml, and the solution is taken50ml of the catalyst is impregnated with the catalyst ca-1-a prepared in the step (2), dried at 110 ℃, and then roasted at 600 ℃ to obtain the catalyst ca-2-f.

Comparative example 1

(1)Al₂O₃The preparation of the support was identical to example 1.

(2) Preparation of cb-1 catalyst

Preparing aqueous solution from ammonium metatungstate, nickel nitrate and citric acid, wherein WO₃Mixing the solution with 200g Al, wherein the concentration of nickel oxide is 65g/100ml, the concentration of nickel oxide is 5g/100ml, and the concentration of citric acid is 10g/100ml₂O₃The carrier is impregnated with the same volume, dried at 110 ℃, and then roasted at 600 ℃ to obtain the catalyst cb-1.

Comparative example 2

(1)A1₂O₃Preparation of the support is in accordance with example 1

(2) Preparation of cb-2 catalyst

Preparing aqueous solution from ammonium metatungstate, nickel nitrate, molybdenum oxide and citric acid, wherein WO₃The concentration is 70g/100ml, the concentration of nickel nitrate is 5g/100ml, the concentration of molybdenum oxide is 10g/100ml, the concentration of citric acid is 10g/100ml, and the solution is mixed with 200g of Al₂O₃The carrier is impregnated with the same volume, dried at 110 ℃, and then roasted at 600 ℃ to obtain the catalyst cb-2.

TABLE 1 compositions of catalysts of examples and comparative examples

TABLE 2 evaluation results of conventional wax activity of each catalyst

Item	Raw material wax	Example 1	Example 2	Comparative example 1	Comparative example 2
						Melting point of	60.2	60.3	62.4	60.3	60.3
The oil content of the oil is high,	0.37	0.35	0.36	0.38	0.37
						color, number	14	30	30	30	30
The stability of the light is high,	6	2	2	3	3
						the nature of the heat-safety signal is determined,	8	30	30	30	30
fe, number ppm	1	0	0	0	0

Note: (1) vulcanization conditions are as follows: the catalyst was first presulfided with Daqing hydrocracked kerosene containing 2 vol% of CS2 under a TC hydrogen atmosphere for 20 hours before being fed.

Reaction conditions are as follows: the reaction temperature is 250 ℃, the pressure is 7.0MPa, and the space velocity (volume) is l.Oh^-1Hydrogen to oil (by volume) ratio 300.

The results of the conventional wax activity evaluation of the catalysts of the examples are shown in table 2, and it can be seen from the table that the oil content and the light stability of the products obtained in the examples 1 and 2 after stepwise complexing impregnation are superior to those of the products obtained in the comparative examples, and the results and the catalysts of the examples improve the dispersion degree of active species on the surface of the alumina carrier through citric acid impregnation and NTA complexing impregnation in the preparation process, thereby improving the utilization rate of active metals. So that the catalyst has high hydrogenation activity.