CN113019406A

CN113019406A - Method for preparing hydrotreating catalyst

Info

Publication number: CN113019406A
Application number: CN201911354030.1A
Authority: CN
Inventors: 樊宏飞; 唐兆吉; 王继锋; 杜艳泽
Original assignee: China Petroleum and Chemical Corp; Sinopec Dalian Research Institute of Petroleum and Petrochemicals
Current assignee: Sinopec Dalian Petrochemical Research Institute Co ltd; China Petroleum and Chemical Corp
Priority date: 2019-12-25
Filing date: 2019-12-25
Publication date: 2021-06-25
Anticipated expiration: 2039-12-25
Also published as: CN113019406B

Abstract

The invention discloses a method for preparing a hydrotreating catalyst. The preparation method of the catalyst comprises the steps of dipping a hydrotreating catalyst carrier by using dipping liquid containing active metal components and chitosan, and drying and roasting to obtain the hydrotreating catalyst. The catalyst is especially suitable for the heavy distillate oil hydrotreating process, and can obviously improve the hydrodenitrogenation activity.

Description

Method for preparing hydrotreating catalyst

Technical Field

The invention relates to a preparation method of a hydrotreating catalyst, in particular to a preparation method of a hydrotreating catalyst suitable for heavy distillate oil.

Background

The crude oil has an increasing degree of heaviness, and the crude oil contains nitrogen, sulfur, oxygen, metal and other impurities, and the impurities not only poison the catalyst in the subsequent treatment process, but also discharge a large amount of harmful gases such as sulfur oxides and nitrogen oxides, thereby endangering the health of human beings and protecting the environment. The catalyst with high activity and good stability is used, so that the process conditions are mild, the hydrogen consumption can be reduced, and the effects of saving energy and reducing consumption are achieved.

The hydrotreating process is to load metal oxide containing VIII and VIB groups in the periodic table into refractory inorganic porous material, and alumina, silica, titania, silicon carbide, boron oxide, zirconia and their combined composite carrier are used. The catalyst precursor is prepared through an impregnation process, and the finished catalyst is prepared through a plurality of drying and roasting processes. The finished catalyst is presulfided before use, i.e., the oxidized catalyst is converted to a sulfided catalyst in the presence of hydrogen sulfide, sulfur-containing organic compounds, or elemental sulfur.

Much work has been done in the art to improve the activity of hydrogenation catalysts, and many documents have been reported.

CN101590416A discloses a method for preparing a molybdenum-nickel hydrogenation catalyst, which comprises the steps of kneading and impregnating to prepare the catalyst, firstly, in the presence of nitric acid, kneading molybdenum oxide, a titanium-containing compound, a phosphorus-containing compound and aluminum oxide, extruding to form strips, drying and roasting to obtain an aluminum oxide forming material containing titanium, phosphorus and molybdenum, then impregnating a nickel-containing phosphoric acid solution, drying and roasting to obtain the molybdenum-nickel hydrogenation catalyst.

CN1052501A discloses a preparation method of a hydrogenation catalyst. In order to improve the activity of the catalyst, the method comprises the steps of adding an auxiliary agent P, F, B into an impregnation liquid containing three metals of Co-W-Mo, impregnating by adopting a segmented impregnation method, drying and roasting to obtain the finished catalyst. The method is characterized in that after the impregnation and loading of the active metal, the active metal component is roasted at high temperature, the acting force between the active metal component and the carrier is strong, the vulcanization effect of the catalyst is influenced, and part of the active metal component is aggregated to influence the dispersion degree of the active metal, so that the activity of the catalyst is influenced.

CN00110018.1 discloses a hydrogenation catalyst and a preparation method thereof, the catalyst takes VIB group and VIII group metals as active components, adopts fluorine as an auxiliary agent, simultaneously carries one or a mixture of a plurality of silicon, boron, magnesium, titanium and phosphorus as the auxiliary agent, and adopts a coprecipitation method as a core technology for preparation.

CN200910236166.2 discloses a preparation method of a paraffin hydrofining catalyst. The method mainly comprises the following steps: adding 6-17% of silicon-containing compound and 2-20% of phosphorus-containing compound solution into pseudo-boehmite dry glue powder, rolling, extruding, drying and roasting to obtain the silicon-and-phosphorus-containing alumina carrier.

In the prior art, the introduction of the auxiliary agent is coprecipitation or is added during forming, the former may cause the active metal and the auxiliary agent to enter a bulk phase in the coprecipitation process, and under the condition of the same precipitation condition, each substance cannot reach the optimal precipitation condition; the latter adds in the assistant during molding, the assistant is difficult to disperse uniformly, the utilization rate of the assistant is reduced obviously, and the use performance of the finished catalyst is greatly influenced.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a preparation method of a hydrotreating catalyst. The catalyst prepared by the method is particularly suitable for a heavy distillate oil hydrotreating process, and can obviously improve the hydrodenitrogenation activity.

The invention provides a preparation method of a hydrotreating catalyst, which comprises the following steps: dipping the hydrotreating catalyst carrier in dipping liquid containing active metal components and chitosan, drying and roasting to obtain the hydrotreating catalyst.

In the method of the invention, the active metal component comprises a metal of the VIII family and a metal of the VIB family. The group VIII metal is Co and/or Ni, and the group VIB metal is W and/or Mo. The hydrotreating catalyst is characterized in that the content of the VIII family metal in terms of oxide is 1-15 wt%, preferably 4-10 wt%, and the content of the VIB family metal in terms of oxide is 10-30 wt%, preferably 15-28 wt%, based on the weight of the catalyst.

In the method, the mole ratio of the chitosan to the VIB group atoms in the impregnating solution is 0.01: 1-10: 1, preferably 0.01: 1-5: 1.

in the method of the present invention, the hydrotreating catalyst carrier may be an inorganic refractory oxide carrier, which is generally an alumina-based carrier, where the alumina-based carrier refers to an alumina-based carrier, which is a main component and may contain no or an auxiliary component, where the auxiliary component may be one or a combination of several of zirconium, silicon, fluorine, phosphorus, titanium, boron, lanthanum, cerium, and the like, and the content of the auxiliary in the alumina carrier is 35wt% or less, preferably 20wt% or less, and more preferably 15wt% or less. The alumina-based carrier of the present invention may further contain other conventional components such as a molecular sieve, for example, at least one of a Y-type molecular sieve, a Beta molecular sieve, and the like.

In the process of the present invention, the hydrotreating catalyst support may be prepared by a conventional method in the art, such as kneading. The general process is as follows: the precursor of the hydrogenation catalyst carrier, such as aluminum hydroxide, an auxiliary agent component and the like, is kneaded and molded, and then dried and roasted to obtain the alumina-based carrier. The roasting conditions can be as follows: the temperature is 500-1000 ℃ for 1.0-30.0 h, preferably 500-700 ℃ for 3.0-10.0 h. The alumina carrier can be prepared by adopting a conventional method. The shape of the carrier can be in a suitable shape such as a strip shape, a spherical shape, and the like, and a conventional forming aid, such as at least one of an extrusion aid, a peptizing acid, a binder, and the like, can be added in the forming process, for example, the extrusion aid can be sesbania powder, and the peptizing acid can be at least one of citric acid, nitric acid, and the like. The binder may be a small pore alumina.

In the method of the invention, organic acid is preferably added into the steeping liquor containing the active metal component and the chitosan, and the organic acid is preferably one or more of citric acid, tartaric acid, malic acid, lactic acid, sorbic acid, gluconic acid, succinic acid and benzoic acid. The mole ratio of the organic acid to the VIB group atoms in the impregnating solution is 0.01: 1-2: 1, preferably 0.01: 1-1: 1.

in the method of the present invention, the impregnation may be an equal-volume impregnation, an excess impregnation, a stepwise impregnation, a co-impregnation, and preferably an equal-volume co-impregnation. Impregnation methods are well known to those skilled in the art. And impregnating the carrier with the impregnating solution, and drying to prepare the final catalyst. Methods for preparing catalysts are well known to the skilled worker. The impregnation solution is prepared by using compounds containing metals of groups VIB and VIII, the concentration of the solution being adjustable by the amount of each compound used, so as to prepare the catalyst with the specified content of active components, the preparation method of the solution being well known to those skilled in the art. In the process of the present invention, the active metal source may be prepared from conventional metal compounds in the preparation of the impregnation solution containing the active metal component, such as: the Co source can be at least one of cobalt nitrate and cobalt chloride, the Ni source can be at least one of nickel sulfate, nickel nitrate, nickel chloride and basic nickel carbonate, the W source can be ammonium metatungstate, and the Mo source can be ammonium heptamolybdate or molybdenum oxide.

In the method of the present invention, the drying conditions are conventional drying, for example, the drying temperature is 60 ℃ to 220 ℃, preferably 90 ℃ to 180 ℃, and the drying time is 0.5h to 10h, preferably 1h to 5 h. The roasting condition is that the temperature is 350-500 ℃, preferably 380-480 ℃, and the roasting time is 0.5-10 h, preferably 1-5 h. The drying and calcination may be carried out in an oxygen-containing atmosphere, and the oxygen concentration is not particularly limited, such as an air atmosphere or the like.

The hydrotreating catalyst prepared by the method can be heavy oil hydrotreating catalyst, is mainly used for removing impurities such as sulfur, nitrogen and the like in heavy distillate oil, and has the following reaction conditions: the total reaction pressure is 3.0-18.0 MPa, and the liquid hourly space velocity is 0.2-4.0 h^-1Hydrogen-oil volume ratio 200: 1-2000: 1, the reaction temperature is 230-430 ℃.

Compared with the prior art, the invention has the following advantages:

1. the catalyst of the invention is especially suitable for hydrogenation and impurity removal (such as sulfur, nitrogen and the like) catalysts of heavy distillate oil, and has large improvement range of hydrogenation and denitrification activity.

2. When the hydrogenation catalyst is prepared, chitosan, especially organic acid, is added into the impregnation liquid containing the active metal component, so that on one hand, the acid content of B is increased under the condition that the total acid content of the catalyst is certain, and on the other hand, when the impregnation liquid containing the active metal component is impregnated, under the action of the chitosan, an active phase in a mosaic state is easily formed on the surface of the catalyst, the content of molybdenum in a precursor of the active phase of the catalyst is increased, and the number of effective active sites is increased. In conclusion, the comprehensive performance of the catalyst is improved, and the catalyst is particularly beneficial to hydrogenolysis of C-N bonds and greatly improving the hydrodenitrogenation activity.

Detailed Description

The effects and effects of the technical solution of the present invention are further illustrated by the following examples and comparative examples, but the present invention should not be construed as being limited to these specific examples, and the following examples and comparative examples of the present invention are mass fractions unless otherwise specified.

In the invention, the determination of the L acid or the B acid adopts an infrared spectroscopy, an instrument adopts an American Nicot Fourier infrared spectrometer-6700, and the determination method comprises the following steps: weighing 20mg of sample with granularity less than 200 meshes, pressing into sheet with diameter of 20mm, placing on sample rack of absorption cell, placing 200mg of sample in cup of instrument, connecting absorption cell and adsorption tube, vacuumizing until vacuum degree reaches 4 × 10^-2And Pa, heating to 500 ℃, keeping for 1 hour to remove adsorbates on the surface of the sample, cooling to room temperature, adsorbing pyridine to saturation, continuously heating to 160 ℃, balancing for 1 hour, and desorbing the physically adsorbed pyridine to obtain the acid content of infrared total acid, B acid and L acid, wherein the unit of the B acid and the L acid is mmol/L.

In the invention, the relative desulfurization activity and the relative denitrification activity are calculated as follows:

the hydrodesulfurization activity of the catalyst was calculated on the 1.7 scale, and the hydrodenitrogenation activity was calculated on the 1 scale.

Hydrodesulfurization activity =

，

Hydrodenitrogenation activity =

，

Relative activity: the hydrodesulfurization activity and hydrodenitrogenation activity of catalyst a were used as references:

the relative desulfurization activity of catalyst B was: hydrodesulfurization activity of catalyst B ÷ hydrodesulfurization activity of catalyst A × 100%,

the relative denitrification activity of catalyst B was: the hydrodenitrogenation activity of catalyst B is multiplied by the hydrodenitrogenation activity of catalyst A by 100%,

the relative desulfurization and denitrification activity of catalyst A at this time was recorded as 100.

Example 1

(1) Preparation of hydrotreating catalyst support

Taking 100g of macroporous aluminum hydroxide dry rubber powder and 50g of small-pore alumina dry rubber powder, adding 6g of citric acid and sesbania powder respectively, and uniformly mixing. Then, 145g of a dilute aqueous nitric acid solution was uniformly added thereto, wherein the nitric acid concentration was 2.5 wt%. Kneading the materials for 15min, grinding for 20min, and extruding with 1.7 mm-diameter clover orifice plate. Drying at 110 deg.C for 4 hr, and calcining at 550 deg.C for 3 hr. The calcined support was designated as Z1.

(2) Catalyst preparation

Impregnating the carrier Z1 with impregnating solution containing Mo, Ni, P, chitosan and citric acid in equal volume, wherein the molar ratio of the chitosan to the Mo in the impregnating solution is 0.06: 1, the molar ratio of citric acid to Mo in the impregnation liquid is 0.02: 1, drying at 110 ℃ for 4h, and roasting at 430 ℃ for 3h to finally obtain the catalyst C-1. The catalyst properties are shown in table 1.

Example 2

(1) Preparation of hydrotreating catalyst support

The support was prepared as in example 1.

(2) Catalyst preparation

Soaking the carrier Z1 in a soaking solution containing Mo, Ni, P, chitosan and gluconic acid in equal volume, wherein the molar ratio of the chitosan to the Mo content in the soaking solution is 0.07: 1, the molar ratio of the gluconic acid to the Mo content in the impregnation liquid is 0.02: drying at 1,120 ℃ for 3h, and calcining at 430 ℃ for 2h to finally obtain the catalyst which is marked as C-2. The catalyst properties are shown in table 1.

Example 3

(1) Preparation of hydrotreating catalyst support

The support was prepared as in example 1.

(2) Catalyst preparation

Soaking Z1 in a soaking solution containing Mo, Ni, P, chitosan and tartaric acid in equal volume, wherein the molar ratio of the chitosan to the Mo content in the soaking solution is 0.08: 1, the molar ratio of tartaric acid to the Mo content in the impregnation liquid is 0.02: the catalyst finally obtained is marked as C-3 after drying at 1,120 ℃ for 3h and calcining at 420 ℃ for 2 h. The catalyst properties are shown in table 1.

Example 4

(1) Preparation of hydrotreating catalyst support

The support was prepared as in example 1.

(2) Catalyst preparation

Soaking Z1 in a soaking solution containing Mo, Ni, P, chitosan and malic acid in equal volume, wherein the molar ratio of the chitosan to the Mo content in the soaking solution is 0.1: 1, the molar ratio of the malic acid to the Mo content in the impregnation liquid is 0.03: the catalyst finally obtained is marked as C-4 after drying at 1,110 ℃ for 3h and roasting at 400 ℃ for 2 h. The catalyst properties are shown in table 1.

Example 5

(1) Preparation of hydrotreating catalyst support

The support was prepared as in example 1.

(2) Catalyst preparation

Soaking the carrier Z1 in a soaking solution containing Mo, Ni, P and chitosan in equal volume, wherein the molar ratio of the chitosan to the Mo in the soaking solution is 0.05: the catalyst finally obtained is marked as C-5 after drying at 1,120 ℃ for 3h and roasting at 400 ℃ for 2 h. The catalyst properties are shown in table 1.

Comparative example 1

The support preparation was the same as in example 1.

Soaking Z1 in soaking solution containing Mo, Ni and P in the same volume, drying at 110 ℃ for 3h, and roasting at 430 ℃ for 3h to obtain the final catalyst C-6. The catalyst properties are shown in table 1.

Comparative example 2

The support preparation was the same as in example 1.

Soaking Z1 in a soaking solution containing Mo, Ni, P and ethylene glycol in equal volume, wherein the molar ratio of the ethylene glycol to the Mo content in the soaking solution is 0.08: the catalyst finally obtained is marked as C-7 after drying at 1,110 ℃ for 3h and roasting at 430 ℃ for 3 h. The catalyst properties are shown in table 1.

Comparative example 3

The support preparation was the same as in example 1.

Impregnating the carrier Z1 with an impregnating solution containing Mo, Ni, P and citric acid in equal volume, wherein the molar ratio of the citric acid to the Mo in the impregnating solution is 0.02: the catalyst finally obtained is marked as C-8 after heat treatment for 4h at 1,110 ℃ and roasting for 3h at 430 ℃. The catalyst properties are shown in table 1.

TABLE 1 composition and Properties of the catalysts

Catalyst numbering	C-1	C-2	C-3	C-4	C-5	C-6	C-7	C-8
									MoO₃，wt%	23.0	23.2	23.1	23.4	23.5	23.1	23.5	23.6
NiO，wt%	3.99	3.89	3.92	3.85	3.89	3.93	3.95	3.90
									P，wt%	1.20	1.19	1.22	1.23	1.22	1.25	1.23	1.23
Acid content B, mmol/g	0.142	0.140	0.139	0.141	0.126	0.079	0.103	0.105

Catalyst evaluation

The catalyst activity evaluation experiment was performed on a 100mL small scale hydrogenation unit, and the catalyst was presulfided prior to evaluation. The evaluation conditions of the catalyst are that the total reaction pressure is 14.5MPa, and the liquid hourly volume space velocity is 1.2 h^-1Hydrogen-oil volume ratio 950: 1, the reaction temperature is 377 ℃. Properties of the raw oil for the activity evaluation test are shown in Table 2, and the results of the activity evaluation are shown in Table 3.

TABLE 2 Properties of the feed oils

Raw oil
		Density (20 ℃ C.), g/cm³	0.930
Sulfur content, wt.%	1.85
		Nitrogen content,. mu.g/g	1960

TABLE 3 evaluation results of catalyst Activity

Catalyst numbering	C-1	C-2	C-3	C-4	C-5	C-6	C-7	C-8
									Relative denitrification activity,%	182	179	181	178	169	100	113	115
Relative desulfurization activity of%	151	148	149	150	140	100	107	110

As can be seen from Table 3, the hydrodesulfurization and denitrification activities, particularly the hydrodenitrogenation activities, were greatly improved with the hydrotreating catalyst of the present invention as compared with the comparative catalyst.

Claims

1. A method of preparing a hydroprocessing catalyst, comprising: dipping the hydrotreating catalyst carrier in dipping liquid containing active metal components and chitosan, drying and roasting to obtain the hydrotreating catalyst.

2. The method of claim 1, wherein: the active metal component comprises a metal in a VIII family and a metal in a VIB family, the molar ratio of chitosan to atoms in the VIB family is 0.01: 1-10: 1, preferably 0.01: 1-5: 1.

3. the method of claim 2, wherein: the metal in the VIII family is Co and/or Ni, and the metal in the VIB family is W and/or Mo.

4. A method according to claim 2 or 3, characterized in that: the hydrotreating catalyst is characterized in that the content of the VIII family metal in terms of oxide is 1-15 wt%, preferably 4-10 wt%, and the content of the VIB family metal in terms of oxide is 10-30 wt%, preferably 15-28 wt%, based on the weight of the catalyst.

5. The method of claim 1, wherein: in the hydrotreating catalyst, the carrier is an inorganic refractory oxide carrier, and preferably an alumina-based carrier.

6. The catalyst according to claim 1 or 4, characterized in that: the hydrotreating catalyst is a heavy oil hydrotreating catalyst.

7. The method of claim 1, wherein: adding organic acid into the steeping liquor containing the active metal component and the chitosan, wherein the organic acid is preferably one or more of citric acid, tartaric acid, malic acid, lactic acid, sorbic acid, gluconic acid, succinic acid and benzoic acid.

8. The method of claim 7, wherein: the content of the organic acid and the mole ratio of the VIB-group atoms in the impregnating solution are respectively 0.01: 1-2: 1, preferably 0.01: 1-1: 1.

9. the method of claim 1, wherein: the impregnation is carried out by co-impregnation with equal volume.

10. The method of claim 1, wherein: the drying conditions were as follows: the drying temperature is 60-220 ℃, preferably 90-180 ℃, and the drying time is 0.5-10 h, preferably 1-5 h; the roasting condition is that the temperature is 350-500 ℃, preferably 380-480 ℃, and the roasting time is 0.5-10 h, preferably 1-5 h.