CN1274788C - Molecular sieve containing catalyst for deep hydrogenation of middle distillate and its preparing method - Google Patents

Abstract

A catalyst containing molecular sieves for advanced hydrotreating of middle distillate oil and its preparation method, the catalyst is mainly suitable for the advanced hydrotreating process of middle distillate oil, especially suitable for low-quality diesel oil (for example: high-sulfur naphthenic straight-run Diesel oil, coked diesel oil, catalytic cracking diesel oil or a mixture of the above diesel oils) is deeply hydrotreated, and the treated diesel oil can be used as a blending component of high-quality diesel oil. The hydrotreating catalyst of the present invention is a domestic macroporous and mesopore gibbsite made by aluminum sulfate through carbon dioxide precipitation method, mixed with cation-exchanged zeolite and then calcined at a high temperature as a carrier, phosphorus and nickel, molybdenum active Component composition.

Description

Molecular sieve-containing catalyst for advanced hydrotreating of middle distillate oil and preparation method thereof

technical field

The invention relates to a molecular sieve-containing catalyst for deep hydrotreating of middle distillates and its preparation technology. It is a middle distillate containing nickel, molybdenum and phosphorus, which is supported by alumina and cation-exchanged zeolite. The hydrogenation treatment catalyst, more specifically relates to a catalyst for the advanced hydrogenation treatment of diesel fractions containing nickel, molybdenum and phosphorus, which is supported by alumina and cation-exchanged zeolite, and a preparation method thereof.

Background technique

Middle distillate hydrotreating catalysts are generally composed of metals or metal oxides with hydrogenation function and supports and additives with certain acidic functions. The commonly used metal components are cobalt-molybdenum, nickel-molybdenum or nickel-tungsten. Recently, there are more and more hydrogenation catalysts using nickel-molybdenum and nickel-tungsten as active components. Inferior diesel oil, especially in China’s inferior diesel fraction, has a high content of nitrogen and aromatics. Therefore, the hydrotreating catalyst with nickel-molybdenum and nickel-tungsten as active components is more suitable for the deep hydrotreating and hydrogenation of China’s inferior diesel fraction. Upgrading. The development direction of this type of catalyst is to improve the activity and selectivity of the catalyst by optimizing the preparation process and changing the properties of the carrier, making it more suitable for deep hydrotreating and hydroupgrading of inferior diesel fractions, and reducing the metal content in the catalyst. content to reduce costs. According to the bibliographical reports in the prior art, 1. US4,188,281 introduced a kind of hydrogenation treatment with VIB, VIIB, VIII group metals as active components and faujasite (adding a small amount of alumina as binder) as carrier Catalyst, the catalyst can be used in the heavy oil hydrotreating process, the tail oil after hydrotreating is used as the raw material for steam cracking to produce ethylene, and the ethylene yield has been greatly improved, but because the catalyst uses zeolite as the main component of the carrier , is that the catalyst has a strong cracking performance, which leads to a low tail oil yield in the hydrogenation process, and at the same time, will inevitably lead to a decrease in the final ethylene production. In addition, since the price of zeolite is higher than that of alumina, the catalyst is relatively expensive compared with catalysts made of alumina as the main carrier. ② In US3,779,903, alumina sol is dried and calcined to obtain a carrier with a pore volume of 0.15-0.45ml/g, then impregnated with nickel and tungsten, dried and calcined to obtain 10-18% by weight nickel oxide and 25% tungsten oxide. ～40% by weight and 1～9% by weight of fluorine, although the catalyst has high activity in hydrodesulfurization, denitrogenation and aromatics saturation, the cost of the catalyst is too high due to the high metal content, especially nickel content. ③US4,330,395 discloses a kind of middle distillate hydrotreating oil prepared by using tungsten compound and aluminum compound as raw material, by evaporating to dryness, roasting, impregnating with nickel compound, and then vulcanizing and fluorinating with sulfur compound and fluorine compound Catalyst, this catalyst also has the shortcoming that the metal content is too high, and its preparation method is also relatively complicated. ④CN85,104,438B adopts high-purity gibbsite prepared by the hydrolysis method of alkoxy aluminum or alkyl aluminum as the precursor of the catalyst carrier, and prepares a kind of nickel oxide containing 1-5 wt%, tungsten oxide 12-35 wt%. %, 1-9 wt% fluorine hydrotreating catalyst, the catalyst has lower metal content and higher hydrogenation activity, but the cracking activity is lower and cannot meet the requirements of hydrotreating process. ⑤CN1,105,053 discloses a catalyst suitable for heavy distillate oil hydrotreating, the catalyst is composed of nickel oxide 1-5% by weight, tungsten oxide 15-38% by weight, fluorine 1-9% by weight, and its carrier is A modified alumina obtained by treating with air and water vapor at high temperature. The pore distribution of the modified alumina is concentrated in the range of 6-20nm. Due to the high-temperature treatment of air and water vapor, this method obviously exists The disadvantages of complex process and high energy consumption. 6. CN1,169,336A discloses a catalyst for the hydrotreating of distillate oil. The catalyst is composed of 1-5% by weight of nickel oxide, 15-38% by weight of tungsten oxide, 1-9% by weight of fluorine, and the rest is alumina. The alumina carrier is composed of one or more small-pore aluminas and one or more macro-porous aluminas in a weight ratio of 75:25 to 50:50, and the micropore diameter of the small-pore aluminas is less than 8nm Alumina whose pore volume accounts for more than 95% of the total pore volume, and macroporous alumina whose micropore diameter is 6-60nm and whose pore volume accounts for more than 70% of the total pore volume. The hydrogenation activity of the catalyst is high, but since more than two kinds of alumina carriers with different pore diameters are used, and different alumina ratios need to be selected according to different processing raw materials, this method obviously has the disadvantage of complicated preparation process. ⑦ Zhao 57--204231 introduced a catalyst made of VIB and VIII group metals as active components, alumina produced by sodium metaaluminate-sulfuric acid method and a small amount of zeolite as a carrier, and fluorine additives. When the catalyst is used in the hydrotreating of distillate oil, its aromatic hydrocarbon saturation performance and cracking performance are greatly improved, but because the alumina produced by sodium metaaluminate-sulfuric acid method has poor physical and chemical properties such as impurity content and crystal phase purity. It is inferior to alumina produced by hydrolysis of aluminum sulfate, so the cracking activity, aromatics saturation performance and refining performance of the catalyst are limited to a certain extent.

Contents of the invention

The object of the present invention is to avoid the disadvantages of the above-mentioned prior art and provide a molecular sieve-containing catalyst for advanced hydrotreating of middle distillates and a preparation method thereof. It is a catalyst for advanced hydrotreating of diesel fraction containing nickel, molybdenum and phosphorus, which is supported by alumina and cation-exchanged zeolite, and a preparation method thereof. Its main technical feature is that the hydrotreating catalyst is a domestically produced large-pore and medium-pore gibbsite made by aluminum sulfate through carbon dioxide precipitation, mixed with cation-exchanged zeolite and then calcined at a high temperature as a carrier, phosphorus, nickel, Composed of molybdenum active components, the content of each component (based on the catalyst, weight%) is: nickel oxide 2.5-8.0%, molybdenum oxide 10-30%, phosphorus 0.2-4.0%, and the rest is carrier, about 60-85% . .

In order to better achieve the above purpose, the carrier is obtained by mixing domestic macroporous and mesopore gibbsite and cation-exchanged zeolite, which is made by aluminum sulfate through carbon dioxide precipitation, and then calcined at high temperature, wherein the weight ratio of zeolite to the carrier is 5 ~35% by weight. The specific surface area of the mesoporous alumina used is more than 270m ² /g, the pore volume is more than 0.7ml/g, the average pore diameter is 7-12nm, and the pore volume of pores with a pore diameter greater than 3nm accounts for more than 95% of the total pore volume; The macroporous alumina has a specific surface area of more than 320m ² /g, a pore volume of more than 0.9ml/g, an average pore diameter of 9-13nm, and the pore volume of pores with a pore diameter greater than 3nm accounts for more than 97% of the total pore volume. The cation-exchanged zeolite used may be Y or Ultrastable Y zeolite having a silica/alumina molar ratio of 4.5 to 7.5. The cations used for ion exchange can be ammonium ions or hydrogen ions.

The preparation method of the molecular sieve-containing catalyst of the present invention is to impregnate with the aqueous solution of precursors of nickel, molybdenum and phosphorus successively after it is carrier molding and roasting, and needs to be dried and roasted after each impregnation, and the specific implementation is through the following Process realized:

1. Preparation of the carrier: The carrier is made of domestic macroporous and mesopore gibbsite made by aluminum sulfate by carbon dioxide precipitation method, mixed with cation-exchanged zeolite, pore expander, extrusion aid and binder, and then extruded It is obtained by drying and roasting at high temperature, and the zeolite in it accounts for 5-35% of the weight of the carrier; the drying temperature is 100-130°C, and the time is 8-24 hours; the roasting temperature is 400-650°C, The time is 2 to 24 hours;

2. Preparation of an aqueous solution containing nickel, molybdenum and phosphorus for impregnation: molybdenum trioxide and basic nickel carbonate are added to the boiled concentrated phosphoric acid solution, and then continue to heat and reflux until fully dissolved to become a dark green clear solution; and The amount of phosphoric acid is controlled so that the weight ratio of P/ _MoO3 is 0.3 to 1.0; the time of reflux is 0.5 to 4.0 hours; and the molybdenum trioxide is prepared by heating and decomposing ammonium molybdate or ammonium paramolybdate, and the heating and roasting temperature is 400～600℃, the time is 2～12 hours;

3. Impregnation of the catalyst: The impregnation method is the equal volume impregnation method. The impregnation cannot be completed at one time, and the impregnation method can be used multiple times. After each impregnation, drying and roasting are required; the drying temperature is 100-130 ° C, and the time is 8 ～24 hours; the calcination temperature is 400～650 ℃, and the time is 2～24 hours.

Detailed ways

The technical characteristics of the present invention will be described in detail below in conjunction with specific embodiments.

1. Examples 1-2 describe the ion exchange process of the zeolites provided by the present invention.

Embodiment 1: take by weighing 150 grams of dealuminated ultra-stable Y-type zeolite DASY (SiO ₂ /Al ₂ O ₃ ratio is 5.7, crystallinity is 72%) produced by Zhoucun Catalyst Factory, and then adding 800 milliliters of concentration is 1.0M Ammonium nitrate (product of Beijing Chemical Plant, analytically pure) aqueous solution, stirred at room temperature for 2 to 3 hours, left to stand for 2 hours, poured off the supernatant, centrifuged, washed repeatedly with distilled water until there was no nitrate ion, and the wet DASY molecular sieves are baked under infrared lamps until dry; put the preliminary dried molecular sieves in an oven at 110-120°C, continue to dry for 3 hours, and then bake at 500°C for 4 hours; repeat the exchange twice with the above method, a total of The ion-exchanged zeolite A can be obtained three times, and its sodium oxide content is less than 0.1% by weight.

Example 2: Weigh 150 grams of ultra-stable Y-type molecular sieve USY _{produced by Zhoucun Catalyst Factory (SiO2/Al2O3 ratio is} 4.8, crystallinity is 68%), and then add 750 milliliters of ammonium nitrate with a concentration of 1.0M (product of Beijing Chemical Plant, analytically pure) aqueous solution, after stirring at room temperature for 2 to 3 hours, let it stand for 2 hours, pour off the supernatant, centrifuge, wash repeatedly with distilled water until there is no nitrate ion, and wet USY molecular sieve Put it under an infrared lamp and bake until dry; put the initially dried molecular sieve into an oven at 110-120°C, continue drying for 3 hours, and then bake at 500°C for 4 hours; repeat the exchange twice with the above method, and exchange three times in total The ion-exchanged zeolite B can be obtained, and its sodium oxide content is less than 0.1% by weight.

2. Examples 3-7 describe the preparation process of the catalyst carrier provided by the present invention.

Embodiment 3: take by weighing 180 grams (by weight on a dry basis) of macroporous hydrated alumina (trade name HF-3111, Shandong Aluminum Company product, wherein the content of gibbsite is 80 wt. %), and 20 grams (by weight on a dry basis) of the zeolite A prepared by Example 1, mix homogeneously, add 5.0 grams of extrusion aid (Vascinia powder), 3.0 milliliters of adhesive (nitric acid (chemically pure)) and 250 ml of water milliliter, extruded into a cylindrical strip with an outer diameter of 1.6 mm, dried at 120°C, and calcined at 500°C for 4 hours to obtain the catalyst carrier Z1.

Embodiment 4: take by weighing 170 grams (by weight on a dry basis) of macroporous hydrated alumina (trade name HF-3111, product of Shandong Aluminum Industry Company) prepared by the aluminum sulfate-carbon dioxide precipitation method, wherein the content of gibbsite is 80 wt. %), and 30 grams (by weight on a dry basis) of the zeolite A prepared by Example 1, mix homogeneously, add 5.0 grams of extrusion aid (Vascinia powder), 3.0 milliliters of adhesive (nitric acid (chemically pure)) and 250 ml of water milliliters, extruded into a cylindrical strip with an outer diameter of 1.6 mm, dried at 120° C., and calcined at 500° C. for 4 hours to obtain the catalyst carrier Z2.

Embodiment 5: Take by weighing 360 grams (by weight on a dry basis) of mesoporous hydrated alumina (trade name HF-1122, product of Shandong Aluminum Industry Co., Ltd., wherein the content of gibbsite is 80 wt. %), and 40 grams (by weight on a dry basis) of the zeolite B prepared by Example 1, mix homogeneously, add 8.0 grams of extrusion aid (Vascinia powder), 5.0 milliliters of adhesive (nitric acid (chemically pure)) and 400 ml of water respectively milliliters, extruded into a cylindrical strip with an outer diameter of 1.6 mm, dried at 120° C., and calcined at 500° C. for 4 hours to obtain the catalyst carrier Z3.

Example 6: Weigh 150 grams of catalyst carrier Z3 and 25 grams of ammonium fluoride, dissolve ammonium fluoride in 150 ml of water, impregnate catalyst carrier Z3 with an equal volume method, dry at 120°C for 3-12 hours, and roast at 500°C for 4 hours , namely the catalyst carrier Z4.

Embodiment 7: Take by weighing 180 grams (by weight on a dry basis) of macroporous hydrated alumina (trade name HF-3111, product of Shandong Aluminum Industry Company) prepared by aluminum sulfate-carbon dioxide precipitation method, wherein the content of gibbsite is 80 wt. %), and 20 grams (by weight on a dry basis) of the zeolite B prepared by Example 1, mix homogeneously, add 5.0 grams of extrusion aid (Vascinia powder), 3.0 milliliters of adhesive (nitric acid (chemically pure)) and 250 ml of water milliliter, extruded into a cylindrical strip with an outer diameter of 1.6 mm, dried at 120°C, and calcined at 500°C for 4 hours to obtain the catalyst carrier Z5.

3. Examples 8-14 describe the preparation steps of the catalyst provided by the present invention.

Embodiment 8: Preparation of molybdenum trioxide used for catalyst preparation provided by the present invention. A certain amount of ammonium molybdate (chemically pure) was weighed and calcined at 450° C. for 4 hours to obtain molybdenum trioxide.

Example 9: Preparation of the molybdenum-nickel-phosphorous mixed aqueous solution containing the impregnated catalyst provided by the present invention. A certain amount of water and concentrated phosphoric acid (chemically pure) are added in the there-necked flask, heated and boiled, a certain amount of basic nickel carbonate (chemically pure) and the molybdenum trioxide prepared by Example 8 are gradually added in the phosphoric acid solution boiled, and then continue Heat to reflux for 1 hour until completely dissolved and become a dark green clear solution to obtain an aqueous solution containing molybdenum-nickel-phosphorus. Table 2 shows the amount of each raw material used.

Examples 10-14: Weigh a certain amount of carriers Z1-Z5 prepared in Examples 3-7 respectively, impregnate the carrier with an equal volume of the mixed aqueous solution containing molybdenum-nickel-phosphorus prepared in Example 9, and dry at 120°C 3-12 hours, 500 ℃ roasting 4 hours, obtain catalyst T1～T5, table 1 has provided the dosage of each raw material, table 2 has provided the composition of the prepared catalyst, table 3 has provided the prepared catalyst and comparative catalyst basic characteristics. Wherein the determination method of NiO and _MoO content is referring to "Petrochemical Analysis Method" (RIPP test method), P360～361, Science Press (1990), the determination method of phosphorus is referring to P376～379 pages of the same book.

The comparative catalyst D1 is a foreign company's commercial diesel hydrotreating catalyst, and the comparative catalyst D2 is a distillate hydrotreating catalyst with excellent activity in China. The basic characteristics of the comparative catalysts are shown in Table 3.

Table 1 Impregnation of molybdenum-nickel-phosphorus Example number carrier number Carrier dosage in grams Impregnation of molybdenum-nickel-phosphorus MoO ₃ g basic nickel carbonate Phosphoric acid mL water ml 1011121314 Z1Z2Z3Z4Z5 100100100100100 31.031.131.033.631.1 9.59.49.510.39.5 3.603.613.603.903.62 1001008080100

Table 2 Catalyst Composition Example number Catalyst number Active component content in the catalyst, weight % MoO ₃ NiO P 1011121314 T1T2T3T4T5 22.121.821.922.322.2 3.94.04.13.94.1 1.361.411.401.381.39

Table 3 The basic characteristics of the catalyst catalyst composition Average pore size/nm Pore volume/cm ³ /g Specific surface area/m ² /g Bulk density/g/cm ³ T1 Mo-Ni-P/Al ₂ O ₃ -HDASY 8.6 0.49 214.2 0.64 T2 Mo-Ni-P/Al ₂ O ₃ -HDASY 8.8 0.48 216.3 0.58 T3 Mo-Ni-P/Al ₂ O ₃ -HUSY 11.2 0.40 122.9 0.80 T4 Mo-Ni-P/F-Al ₂ O ₃ -HUSY 11.7 0.30 102.4 1.01 T5 Mo-Ni-P/Al ₂ O ₃ -HUSY 10.8 0.40 130.5 0.84 D1 - 7.2 0.32 167.6 1.02 D2 W-Mo-Ni-P/Al ₂ O ₃ 9.4 0.31 132.4 1.00

Invention effect

Because the invention adopts a unique carrier treatment method and an active component impregnation solution preparation method, the catalyst provided by the invention has higher catalytic activity than the prior art. Comparative studies have shown that the cost of diesel hydrogenation catalysts and foreign catalysts whose catalytic activity exceeds the domestic best level is significantly reduced due to the use of domestic carriers and modifiers. It is especially suitable for the hydrotreating of petroleum fractions with a process flow of 180-550°C, especially for the advanced hydrotreating of low-quality diesel fractions with high sulfur, high nitrogen, and high aromatics. The catalyst provided by the invention is used in conjunction with the hydrorefining catalyst Then it can be used in hydro-upgrading of petroleum fractions, especially in the process of hydro-upgrading in medium pressure.

Claims (3)

1. molecular sieve catalyst that contains that is used for the intermediate oil Deep Hydrotreating, it mainly is to process by nickel oxide, molybdenum oxide, phosphorus and by macroporous aluminium oxide, mesoporous aluminas and the complex carrier made through the zeolite molecular sieve of cationic exchange, it is characterized in that the weight ratio of each component:

Nickel oxide: 2.5～8.0%,

Molybdenum oxide: 10～30%,

Phosphorus: 0.2～4.0%,

Complex carrier: 60～85%;

Wherein to account for the vehicle weight ratio be 5～35% to zeolite molecular sieve.

2. according to the described molecular sieve catalyst that contains that is used for the intermediate oil Deep Hydrotreating of claim 1, it is characterized in that described complex carrier is to be obtained with roasting after zeolite molecular sieve through cationic exchange mixes through macropore that the carbonic acid gas precipitator method are made and mesopore one diaspore by Tai-Ace S 150.

3. described preparation method who contains molecular sieve catalyst who is used for the intermediate oil Deep Hydrotreating of claim 1 is characterized in that preparation technology realizes by following operation:

1. the preparation of carrier: carrier be by Tai-Ace S 150 through domestic macroporous that the carbonic acid gas precipitator method are made and mesopore one diaspore with after zeolite, expanding agent, extrusion aid and binding agent through cationic exchange mixes, through extruded moulding, drying and high-temperature roasting obtain again, and make zeolite wherein account for 5～35% of vehicle weight; Its drying temperature is 100～130 ℃, and the time is 8～24 hours; Maturing temperature is 400～650 ℃, and the time is 2～24 hours;

2. the preparation that is used for flooding: be that molybdic oxide and basic nickel carbonate are added the concentrated phosphoric acid that boils, continue reflux then and become the deep green settled solution up to dissolving fully with the aqueous solution of nickeliferous, molybdenum and phosphorus; And the consumption of phosphoric acid is controlled at P/MoO ₃Weight ratio be 0.3～1.0; The time of refluxing is 0.5～4.0 hour; And this molybdic oxide is to adopt ammonium molybdate or the preparation of ammonium paramolybdate thermal degradation, and the heating maturing temperature is 400～600 ℃, and the time is 2～12 hours;

3. the dipping of catalyzer: dipping method is to adopt equi-volume impregnating, and single-steeping is intact, can adopt multiple maceration, all need carry out drying, roasting behind each dipping; Its drying temperature is 100～130 ℃, and the time is 8～24 hours; Maturing temperature is 400～650 ℃, and the time is 2～24 hours.