CN113019406B

CN113019406B - Method for preparing hydrotreating catalyst

Info

Publication number: CN113019406B
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: 2023-11-07
Anticipated expiration: 2039-12-25
Also published as: CN113019406A

Abstract

The invention discloses a method for preparing a hydrotreating catalyst. The preparation method of the catalyst comprises the steps of impregnating a hydrotreating catalyst carrier with an impregnating solution containing active metal components and chitosan, drying and roasting to obtain the hydrotreating catalyst. The catalyst is particularly 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 heavy degree of crude oil is continuously increased, the crude oil contains nitrogen, sulfur, oxygen, metal and other impurities, and the existence of the impurities not only poisons the catalyst in the subsequent treatment process, but also discharges a large amount of sulfur oxides, nitrogen oxides and other harmful gases, thereby endangering the health of human beings and protecting the environment. The catalyst with high activity and good stability can not only alleviate the process conditions, but also reduce the hydrogen consumption, thereby achieving the effects of energy conservation and consumption reduction.

The hydrotreating process is carried out by loading refractory inorganic porous materials with oxides of metals from groups VIII and VIB of the periodic Table, typically with alumina, silica, titania, silicon carbide, boria, zirconia, and combinations thereof. The catalyst precursor is prepared through an impregnation process, and then the finished catalyst is prepared through a plurality of steps of drying and roasting procedures. The finished catalyst is presulfided prior to use, i.e., the oxidation state catalyst is converted to a sulfided catalyst in the presence of hydrogen sulfide, sulfur-containing organic compounds, or elemental sulfur.

The art has made a great deal of work in improving 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-impregnating to prepare the catalyst, kneading molybdenum oxide, titanium-containing compound, phosphorus-containing compound and alumina in the presence of nitric acid, extruding to form strips, drying, roasting to obtain an alumina formed product containing titanium, phosphorus and molybdenum, impregnating with a nickel-containing phosphoric acid solution, and drying and roasting to obtain the molybdenum-nickel hydrogenation catalyst.

CN1052501a discloses a process for preparing a hydrogenation catalyst. In order to improve the activity of the catalyst, the auxiliary agent P, F, B is added into the impregnating solution containing the Co-W-Mo trimetallic, the impregnation is carried out by adopting a sectional impregnation method, and the finished catalyst is obtained after drying and roasting. The method is characterized in that the active metal is impregnated and loaded, and then the active metal component and the carrier are subjected to high-temperature roasting, so that the acting force of 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, the dispersity of the active metal is influenced, and the activity of the catalyst is further influenced.

CN00110018.1 discloses a hydrogenation catalyst and its preparation method, the catalyst uses group VIB and group VIII metals as active components, fluorine is used as auxiliary agent, at the same time one or several of silicon, boron, magnesium, titanium and phosphorus are carried as auxiliary agent, and the core technology is that coprecipitation method is used for preparation.

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

In the prior art, the auxiliary agent is introduced by coprecipitation or is added during forming, the former can cause active metal and the auxiliary agent to enter the bulk phase in the coprecipitation process, and under the condition of the same precipitation condition, each substance cannot reach the optimal precipitation condition; and the auxiliary agent is added during molding, so that the auxiliary agent is difficult to uniformly disperse, the utilization rate of the auxiliary agent is obviously reduced, and the usability of the finished catalyst is greatly influenced.

Disclosure of Invention

Aiming at the defects existing in the prior art, the invention provides a preparation method of a hydrotreating catalyst. The catalyst prepared by the method is particularly suitable for the 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: impregnating a hydrotreating catalyst carrier with an impregnating solution containing an active metal component and chitosan, and drying and roasting to obtain the hydrotreating catalyst.

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

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

in the method of the present invention, the hydrotreating catalyst support may be an inorganic refractory oxide support, typically an alumina-based support, which means that alumina is used as a main component, and may contain no or no auxiliary component, wherein the auxiliary component may be one or a combination of several of zirconium, silicon, fluorine, phosphorus, titanium, boron, lanthanum, cerium, etc., and the content of the auxiliary in the alumina support is below 35wt%, preferably below 20wt%, and more preferably below 15 wt%. The alumina-based carrier of the present invention may further contain at least one of other conventional components such as molecular sieves, e.g., Y-type molecular sieves, beta-type molecular sieves, etc.

In the process of the present invention, the hydrotreating catalyst support may be prepared by a conventional method in the art, such as a kneading method or the like. The general process is as follows: the precursor of the hydrotreatment 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: roasting at 500-1000 deg.c for 1.0-30.0 hr, preferably 3.0-h-10.0 h at 500-700 deg.c. The alumina support may be prepared by conventional methods. The carrier may be in a shape of bar, sphere, etc., and conventional molding aids such as at least one of extrusion aid, peptizing acid, binder, etc. may be added during the molding process, for example, the extrusion aid may be sesbania powder, and the peptizing acid may be at least one of citric acid, nitric acid, etc. The binder may be a small pore alumina.

In the method of the invention, the impregnating solution containing the active metal component and chitosan is preferably added with organic acid, 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 molar ratio of the dosage of the organic acid to the atom of VIB group in the impregnating solution is 0.01: 1-2: 1, preferably 0.01:1 to 1:1.

in the process of the invention, the impregnation may be an isovolumetric impregnation or an overdose impregnation, a stepwise impregnation or a co-impregnation, preferably an isovolumetric co-impregnation. Impregnation methods are well known to those skilled in the art. The carrier is impregnated with the impregnating solution and then dried to obtain the final catalyst. Methods of catalyst preparation are well known to the skilled artisan. Impregnating solutions are prepared by using compounds containing metals of groups VIB and VIII, the concentration of which can be adjusted by the amounts of the respective compounds, in order to prepare catalysts having the indicated active component content, the preparation of which solutions is known to the person skilled in the art. In the process of the present invention, in preparing the impregnation fluid containing the active metal component, the active metal source may be prepared using conventional metal compounds, 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 process 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 0.5 to 10 hours, preferably 1 to 5 hours. 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 firing may be performed 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 of the invention can be a heavy oil hydrotreating catalyst, and is mainly used for removing sulfur, nitrogen and other impurities in heavy distillate oil, and the reaction conditions are as follows: the total reaction pressure is 3.0-18.0 MPa, and the liquid hourly space velocity is 0.2-4.0 h ^-1 Hydrogen 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 impurity removal (such as sulfur, nitrogen and the like) catalyst of heavy distillate oil, and has larger improvement range of hydrogenation denitrification activity.

2. According to the preparation method, when the hydrotreating catalyst is prepared, chitosan, especially organic acid, is added into the impregnation liquid containing the active metal component, so that on one hand, the proportion of B acid is increased under the condition that the total acid amount of the catalyst is certain, and on the other hand, when the active component impregnation liquid is impregnated, under the action of the chitosan, the active phase in an embedded state is easily formed on the surface of the catalyst, the content of octahedral molybdenum of a precursor of the active phase of the catalyst is increased, and the number of effective active bits 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 improves hydrodenitrogenation activity.

Detailed Description

The following examples and comparative examples further illustrate the operation and effect of the technical scheme of the present invention, but the present invention should not be construed as being limited to the specific examples, and the following examples and comparative examples of the present invention are all mass percentages unless otherwise specified.

In the present invention, the L-acid or B-acid is measuredThe method adopts an infrared spectrometry method, an instrument adopts an American Nicot Fourier infrared spectrometer-6700, and the measuring method is as follows: weighing 20mg of sample with granularity smaller than 200 meshes, pressing into sheet with diameter of 20mm, placing on sample rack of absorption cell, placing 200mg of sample into instrument suspension cup, connecting absorption cell and adsorption tube, vacuumizing to vacuum degree of 4X10 ^-2 And (3) heating to 500 ℃ in Pa, keeping for 1 hour to remove adsorbate on the surface of the sample, cooling to room temperature, adsorbing pyridine to saturation, continuously heating to 160 ℃ and balancing for 1 hour, and further obtaining the acid amounts of the infrared total acid, the B acid and the L acid, wherein the unit of the B acid and the L acid is mmol/L.

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

the hydrodesulphurisation activity of the catalyst was calculated on a level 1.7 and the hydrodenitrogenation activity was calculated on a level 1.

Hydrodesulfurization Activity =，

Hydrodenitrogenation Activity =，

Relative activity: the hydrodesulphurisation activity and hydrodenitrogenation activity of catalyst a served as references:

the relative desulfurization activity of catalyst B was: hydrodesulfurization Activity of catalyst B catalyst A hydrodesulfurization Activity X100%,

the relative denitrification activity of catalyst B is: hydrodenitrogenation activity of catalyst B ≡hydrodenitrogenation activity of catalyst a × 100%,

the relative desulfurization and relative denitrification activities of catalyst A at this time were noted as 100.

Example 1

(1) Preparation of hydrotreating catalyst supports

Taking 100g of macroporous aluminum hydroxide dry gel powder and 50g of microporous aluminum oxide dry gel powder, adding 6g of citric acid and sesbania powder respectively, and uniformly mixing. Then 145g of a dilute aqueous nitric acid solution, in which the nitric acid concentration is 2.5% by weight, was added uniformly. Kneading the materials for 15min, rolling for 20min, and extruding strips with clover orifice plate with diameter of 1.7 mm. Drying at 110 deg.c for 4 hr, and roasting at 550 deg.c for 3 hr. The calcined support was designated as Z1.

(2) Catalyst preparation

The carrier Z1 is impregnated with an impregnating solution containing Mo, ni, P, chitosan and citric acid in an equal volume, and the mol ratio of the chitosan to the Mo in the impregnating solution is 0.06:1, the mole ratio of citric acid to Mo in the impregnating solution is 0.02:1, drying at 110 ℃ for 4 hours, and roasting at 430 ℃ for 3 hours, wherein the finally obtained catalyst is designated as C-1. The catalyst properties are shown in Table 1.

Example 2

(1) Preparation of hydrotreating catalyst supports

The preparation method of the carrier is the same as in example 1.

(2) Catalyst preparation

The carrier Z1 is impregnated with the impregnating solution containing Mo, ni, P, chitosan and gluconic acid in an equal volume, and the molar ratio of the chitosan to the Mo content in the impregnating solution is 0.07:1, the mol ratio of the gluconic acid to the Mo content in the impregnating solution is 0.02: after drying at 1,120℃for 3 hours and calcining at 430℃for 2 hours, the finally obtained catalyst was designated as C-2. The catalyst properties are shown in Table 1.

Example 3

(1) Preparation of hydrotreating catalyst supports

The preparation method of the carrier is the same as in example 1.

(2) Catalyst preparation

The Z1 is impregnated by the impregnating solution containing Mo, ni, P, chitosan and tartaric acid in equal volume, and the mole ratio of the chitosan to the Mo content in the impregnating solution is 0.08:1, the molar ratio of tartaric acid to Mo content in the impregnating solution is 0.02: after drying at 1,120℃for 3 hours and calcining at 420℃for 2 hours, the finally obtained catalyst was designated as C-3. The catalyst properties are shown in Table 1.

Example 4

(1) Preparation of hydrotreating catalyst supports

The preparation method of the carrier is the same as in example 1.

(2) Catalyst preparation

The Z1 is impregnated by the impregnating solution containing Mo, ni, P, chitosan and malic acid in equal volume, and the mol ratio of the chitosan to the Mo content in the impregnating solution is 0.1:1, the molar ratio of malic acid to Mo content in the impregnating solution is 0.03: after drying at 1,110℃for 3 hours and calcining at 400℃for 2 hours, the final catalyst was designated C-4. The catalyst properties are shown in Table 1.

Example 5

(1) Preparation of hydrotreating catalyst supports

The preparation method of the carrier is the same as in example 1.

(2) Catalyst preparation

The carrier Z1 is impregnated with an impregnating solution containing Mo, ni, P and chitosan in an equal volume, and the mol ratio of the chitosan to the Mo in the impregnating solution is 0.05: after drying at 1,120℃for 3 hours and calcining at 400℃for 2 hours, the final catalyst was designated C-5. The catalyst properties are shown in Table 1.

Comparative example 1

The carrier preparation was as in example 1.

Z1 is impregnated with an impregnating solution containing Mo, ni and P in an equal volume, dried for 3 hours at 110 ℃, and baked for 3 hours at 430 ℃, and the finally obtained catalyst is marked as C-6. The catalyst properties are shown in Table 1.

Comparative example 2

The carrier preparation was as in example 1.

Z1 is impregnated with impregnating solution containing Mo, ni, P and glycol in equal volume, and the mol ratio of the glycol to the Mo content in the impregnating solution is 0.08: after drying at 1,110℃for 3 hours and calcining at 430℃for 3 hours, the final catalyst was designated C-7. The catalyst properties are shown in Table 1.

Comparative example 3

The carrier preparation was as in example 1.

The carrier Z1 is impregnated with an equal volume of an impregnating solution containing Mo, ni, P and citric acid, and the molar ratio of the citric acid to the Mo in the impregnating solution is 0.02: after heat treatment at 1,110℃for 4 hours and calcination at 430℃for 3 hours, the finally obtained catalyst was designated as C-8. 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
									MoO ₃ ，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
B acid content, mmol/g	0.142	0.140	0.139	0.141	0.126	0.079	0.103	0.105

Catalyst evaluation

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

TABLE 2 oil Properties of raw materials

Raw oil
		Density (20 ℃), g/cm ³	0.930
Sulfur content, wt%	1.85
		Nitrogen content, μg/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, percent	151	148	149	150	140	100	107	110

As can be seen from Table 3, the activity of both hydrodesulfurization and denitrification, especially the activity of hydrodenitrogenation, was greatly improved with the hydrotreating catalyst of the present invention as compared with the comparative catalyst.

Claims

1. A method of preparing a hydrotreating catalyst, the hydrotreating catalyst being a heavy oil hydrotreating catalyst, the method comprising: impregnating a hydrotreating catalyst carrier with an impregnating solution containing an active metal component, chitosan and an organic acid, drying and roasting to obtain a hydrotreating catalyst, wherein the organic acid is one or more of citric acid, tartaric acid, malic acid, lactic acid, sorbic acid, gluconic acid, succinic acid and benzoic acid; the active metal component comprises a VIII group metal and a VIB group metal; the VIII metal is Co and/or Ni, and the VIB metal is W and/or Mo; the drying conditions were as follows: the drying temperature is 60-220 ℃, and the drying time is 0.5-10 h; the roasting condition is that the temperature is 350-500 ℃ and the roasting time is 0.5-10 h.

2. The method according to claim 1, characterized in that: the molar ratio of chitosan to VIB group atoms is 0.01:1 to 10:1.

3. the method according to claim 1, characterized in that: the molar ratio of chitosan to VIB group atoms is 0.01:1 to 5:1.

4. the method according to claim 1 or 2, characterized in that: the hydrotreating catalyst takes the weight of the catalyst as a reference, the content of the metal in the VIII family is 1-15 wt% based on oxide, and the content of the metal in the VIB family is 10-30 wt% based on oxide.

5. The method according to claim 4, wherein: the hydrotreating catalyst takes the weight of the catalyst as a reference, the content of the metal in the VIII group is 4-10wt% based on oxide, and the content of the metal in the VIB group is 15-28wt% based on oxide.

6. The method according to claim 1, characterized in that: in the hydrotreating catalyst, the carrier is an inorganic refractory oxide carrier.

7. The method according to claim 6, wherein: the carrier is an alumina-based carrier.

8. The method according to claim 1, characterized in that: the molar ratio of the content of the organic acid to the atom of VIB group in the impregnating solution is 0.01: 1-2: 1.

9. the method according to claim 8, wherein: the molar ratio of the content of the organic acid to the atom of VIB group in the impregnating solution is 0.01:1 to 1:1.

10. the method according to claim 1, characterized in that: the impregnation adopts isovolumetric co-impregnation.

11. The method according to claim 1, characterized in that: the drying conditions were as follows: the drying temperature is 90-180 ℃ and the drying time is 1-5 h; the roasting condition is that the temperature is 380-480 ℃ and the roasting time is 1-5 h.