CN108014781B

CN108014781B - Hydrogenation catalyst, preparation method and application thereof

Info

Publication number: CN108014781B
Application number: CN201610931671.9A
Authority: CN
Inventors: 刘锋; 褚阳; 李明丰; 李会峰; 习远兵
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: 2016-10-31
Filing date: 2016-10-31
Publication date: 2021-03-12
Anticipated expiration: 2036-10-31
Also published as: CN108014781A

Abstract

The invention relates to the field of hydrorefining and discloses a hydrogenation catalyst, a preparation method and application thereof, wherein the preparation method comprises the following steps: (1) impregnating the carrier with a solution containing a group VIB metal compound; (2) carrying out first vulcanization on the solid material obtained in the step (1) to obtain a semi-finished catalyst; (3) impregnating the semi-finished catalyst with a solution containing a group VIII metal compound; (4) and (4) carrying out second vulcanization on the solid material obtained in the step (3). The hydrogenation catalyst prepared by the method can realize effective removal of mercaptan under the condition of low octane number loss even at low reaction temperature and reaction pressure, and is very suitable for removal of mercaptan in gasoline.

Description

Hydrogenation catalyst, preparation method and application thereof

Technical Field

The invention relates to the field of hydrofining, in particular to a preparation method of a hydrogenation catalyst, the hydrogenation catalyst prepared by the preparation method and application of the hydrogenation catalyst in gasoline hydrogenation sweetening.

Background

At present, air pollution causes more and more serious environmental problems, and tail gas emitted by automobile engines becomes a main source of urban air pollution. SO is generated after sulfur in gasoline is combusted_xCausing serious pollution to air and sulfur content in gasoline in all countries of the worldStrict limitation is proposed, the step of limiting the sulfur content in gasoline in China is also gradually accelerated, the national standard of clean gasoline similar to the Euro IV emission standard is implemented in 2014, the national standard of clean gasoline similar to the Euro V emission standard is implemented in 2017, the sulfur content in the gasoline is required to be not higher than 10 mu g/g, and researchers develop clean gasoline production technologies in succession under the background to meet market requirements.

In China, the proportion of the catalytic cracking gasoline in a gasoline pool is relatively high, and the sulfur content of the catalytic cracking gasoline is high, so that the removal of sulfur in the catalytic cracking gasoline is the most urgent problem. The most difficult sulfur in the catalytically cracked gasoline is thiophene sulfide, and the sulfur can be removed by improving the hydrogenation reaction conditions in the prior art, but the catalytically cracked gasoline contains a large amount of olefins which are high-octane components in the gasoline, and the severe hydrogenation reaction conditions easily cause olefin saturation and octane number loss, so that the olefin saturation is reduced to the maximum extent while the sulfide in the catalytically cracked gasoline is removed.

Researchers find that the remaining sulfides which are not completely removed are mainly thiol compounds in the process of producing clean gasoline with the sulfur content of less than 10 mug/g, the thiol compounds are generated by addition reaction of hydrogen sulfide generated after thiophene hydrodesulfurization and olefin in gasoline, the reaction is a reversible reaction which is difficult to remove due to thermodynamic equilibrium, and if the conventional hydrodesulfurization catalyst is used for removing the thiol, very harsh reaction conditions are required, which inevitably causes great loss of the octane number of gasoline products.

Therefore, it is necessary to develop a novel mercaptan removal method and a catalyst.

In the development of a mercaptan removal method, U.S. Pat. No. 3, 6231754, 1 discloses a mercaptan removal method for removing mercaptans from naphtha by carrying out mercaptan decomposition reaction at a high reaction temperature by using a partially deactivated catalyst (with the activity of 2-40% of the new catalyst), wherein the partially deactivated catalyst can exert the activity of the catalyst at the high reaction temperature (305-455 ℃) without causing hydrogenation saturation of olefins, and has better mercaptan removal selectivity. US6387249B1 discloses a process for removing mercaptans from naphtha by decomposing mercaptans from naphtha using a CoMo catalyst under conditions of high reaction temperature and low reaction pressure, the high reaction temperature being thermodynamically favorable for removal of mercaptans and suppression of the regeneration reaction of mercaptans, and the low reaction pressure being favorable for suppression of the regeneration reaction of mercaptans. The disadvantages of the above-described processes are high reaction temperatures and high investment and energy consumption of the apparatus.

Regarding the development aspect of the catalyst, the traditional preparation technology mainly adopts an impregnation means to introduce an oxidized precursor of an active component into a carrier pore channel, and then the catalyst is aged, dried and roasted to obtain the hydrogenation catalyst. Wherein the Co, Ni, Mo and W active components are present in the form of oxides. However, in actual use, the active components of the hydrogenation catalyst exist in the form of sulfides of Co, Ni, Mo and W, so that the hydrogenation catalyst is subjected to sulfidation activation, namely presulfiding, before use. Although the traditional preparation technology is applied to large-scale industry due to the advantages of simple operation, low cost and the like, the traditional preparation technology still has a series of problems. On the one hand, when the oxidized active component is used as a precursor, the oxidized active component reacts with Al in the impregnation aging process or the drying roasting process₂O₃The surface often has strong interaction, which not only easily causes uneven dispersion of active components on the surface of the carrier, but also causes excessive generation of Al-O-Mo chemical bonds, and then leads to difficulty in completely forming excessive low-activity I-type active phases during vulcanization of the active components, and the utilization rate of active metals is low. In addition, taking Mo-based catalyst preparation as an example, the commonly used precursor ion Mo₇O₂₄ ^6-Tends to induce Al₂O₃Surface dissociation to produce Al³⁺Subsequently reacted therewith to form the Anderson type heteropolyanion Al (OH)₆Mo₆O₁₈ ^3-The large-grain MoO which is difficult to be fully vulcanized and is not beneficial to improving the catalytic activity is generated through roasting₃And Al₂(MoO₄)₃Therefore, it is difficult to achieve both high active component dispersion degree and high sulfidation degree of the hydrogenation catalyst by using the traditional impregnation technology, so that the catalytic activity and selectivity are not ideal. On the other hand, in the vulcanization process of the oxidation type catalyst, the auxiliary agent Co and/or Ni is/are more main agent metalMo and/or W is easier to be vulcanized to form sulfides of Co and/or Ni, and the main metal Mo and/or W is not completely vulcanized at the moment, and the Co and/or Ni can not well play the role of an auxiliary agent, so that the catalytic activity and the selectivity are not ideal.

In recent years, in order to further improve the hydrorefining performance of the catalyst and solve the problem of poor activity caused by excessively strong interaction between an active component and a carrier in a conventional impregnation method, some researches introduce an organic complexing agent while introducing a multi-element active metal component, the obtained catalyst does not need to be calcined, and the developed technology is generally called as a complexing impregnation technology.

CN102909027A discloses a preparation method of an ultra-low sulfur hydrofining catalyst, which is A1₂O₃-SiO₂-ZrO₂The ternary composite oxide is used as a carrier, W-Mo-Ni-Co quaternary metal is used as an active metal component, P is used as an auxiliary agent, an active metal Co-immersion liquid is prepared by adopting a complexing method, and the W-Mo-Ni-Co quaternary active metal component and the P auxiliary agent are loaded on the carrier by adopting a step-by-step saturated immersion technology, so that the prepared catalyst has better low-temperature reaction activity, and can produce the ultra-low sulfur diesel oil with the sulfur content of less than 10 mu g/g under the lower reaction severity compared with the similar catalyst.

CN100469440C, CN102909027A disclose that Ni-W-Mo ternary metal hydrogenation catalysts are prepared by introducing organic dispersing agents or complexing agents (such as ethylene glycol, oxalic acid, citric acid, ethylene diamine tetraacetic acid, nitrilotriacetic acid, etc.) into the carrier during the preparation process. Compared with the catalyst provided by the existing method, the obtained catalyst has better hydrofining performance.

Although the above method of adding complexing agent can improve the hydrorefining performance of the catalyst to some extent, further research shows that the activity and selectivity of the catalyst for removing mercaptan prepared by the above method still need to be further improved.

In summary, although the prior art method improves the mercaptan removal activity and selectivity of the hydrogenation catalyst to a certain extent, the improvement degree is limited, and the reaction conditions are harsh. Therefore, there is a need to develop a hydrogenation catalyst with higher mercaptan removal activity and better selectivity under mild reaction conditions.

Disclosure of Invention

Aiming at the defects of low mercaptan removal activity, poor selectivity and harsh reaction conditions of the hydrogenation catalyst in the prior art, the invention provides a novel preparation method of the hydrogenation catalyst, the hydrogenation catalyst prepared by the preparation method and the application of the catalyst in the hydrogenation and mercaptan removal of gasoline.

The invention provides a preparation method of a hydrogenation catalyst, which comprises the following steps:

(1) impregnating the carrier with a solution containing a group VIB metal compound;

(2) carrying out first vulcanization on the solid material obtained in the step (1) to obtain a semi-finished catalyst;

(3) impregnating the semi-finished catalyst with a solution containing a group VIII metal compound;

(4) and (4) carrying out second vulcanization on the solid material obtained in the step (3).

The invention also provides a hydrogenation catalyst prepared by the preparation method and application thereof in gasoline hydrogenation sweetening.

The inventor of the invention discovers through research that in the preparation process of the catalyst, VIB group metals are firstly introduced into a carrier, then first-step vulcanization is carried out to obtain a semi-finished catalyst, then VIII group metals are introduced, and the catalyst obtained by re-vulcanization also has higher hydrogenation sweetening activity and selectivity under a milder condition. The reason for this is presumably that the inventors found that the catalytic activity sites required for the reaction of hydrogen sulfide with olefins to form mercaptans are different from the catalyst activity sites required for the mercaptan removal reaction, and that under milder reaction conditions and in the presence of a large amount of hydrogen sulfide in the reaction atmosphere, the catalyst is required to have higher mercaptan removal activity and lower mercaptan formation activity, i.e., higher mercaptan removal/formation selectivity₂Higher, mercaptan removal/formation separationThe selectivity is high, but if one-step sulfurization is used, excessive VIII group metals are first sulfurized to generate independent crystals, and the independent crystals do not generate a synergistic effect with VIB group metals, so that the mercaptan removal/generation selectivity of the catalyst is reduced, and the two-step sulfurization method plays a positive role. On one hand, the VIB group metal forms corresponding sulfide after first vulcanization, then the VIII group metal is introduced, in the second vulcanization process, the VIB group metal is mostly vulcanized, in the process that the VIII group metal is vulcanized, enough VIB group metal sulfide receives VIII group metal sulfide, the vulcanized VIII group metal atom easily occupies the corner position of the vulcanized VIB group metal crystal phase, and more VIB group metal sulfide modified by the VIII group metal is generated, therefore, the Co (Ni) -Mo (W) -S active phase is more favorably formed, and the Co (Ni) -Mo (W) -S active phase is more favorably improved in hydrogenation sweetening activity and selectivity of the catalyst; on the other hand, in the second sulfurizing process, the VIB group metal can be further sulfurized, and with the deepening of the sulfurization reaction of the VIII group metal, the VIII group metal and the VIB group metal are finally simultaneously sulfurized, so that the utilization rate of the active metal is effectively improved, and the hydrodesulfurizing activity and selectivity of the catalyst are further improved.

In a preferable case, the first sulfidation in the method provided by the present invention is dry (gas phase) sulfidation, which is more favorable for preparing a cleaner semi-finished catalyst, so that the surface of the metal sulfide in the semi-finished catalyst does not contain impurities, and is more favorable for the subsequent sulfidation of the group VIII metal and the formation of co (ni) -mo (w) -S, on the other hand, the dry sulfidation provides a more stable hydrogen sulfide source, and is more favorable for the subsequent formation of more complete co (ni) -mo (w) -S, thereby improving the hydrodethiolation activity and selectivity of the catalyst.

In another preferred aspect, the process of the present invention provides a method wherein the sulfidation degree of the group VIB metal in the semifinished catalyst obtained by the first sulfidation is limited to above 50%, more preferably 55-75%, and even more preferably 60-70%. The inventor of the present invention found in the research process that when the sulfidation degree of the group VIB metal in the semi-finished catalyst is 60-70%, the hydrodethiolation activity and selectivity of the catalyst are better, and the reason may be that when the sulfidation degree of the group VIB metal is lower, in the second sulfidation process, there is not enough group VIB metal sulfide to accept when more group VIII metal is exposed after sulfidation, more independent group VIII metal sulfide is easily formed, and the effect of modifying group VIB metal sulfide is not achieved, i.e., the group VIII metal delayed sulfidation effect is weaker, and is not easy to form co (ni) -mo (w) -S active phase, while when the sulfidation degree of the group VIB metal in the semi-finished catalyst is higher, it is indicated that more complete group VIB metal sulfide has been formed, and a group VIB metal sulfide with a larger crystal size and is more stable is formed, even if VIII group metal is introduced subsequently, the effect of the auxiliary agent is low, and the effect of two-step vulcanization cannot be fully reflected.

The hydrogenation catalyst prepared by the preparation method of the hydrogenation catalyst provided by the invention can realize effective removal of mercaptan under the condition of low octane number loss even at low reaction temperature and reaction pressure, and is very suitable for removal of mercaptan in gasoline, especially for selective removal of mercaptan in a reaction environment with hydrogen sulfide.

Additional features and advantages of the invention will be set forth in the detailed description which follows.

Detailed Description

The following describes in detail specific embodiments of the present invention. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.

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 the present invention, preferably, the group VIB metal is molybdenum and/or tungsten, and the group VIII metal is cobalt and/or nickel.

In the present invention, there is no particular limitation on the group VIB metal compound and the group VIII metal compound, for example, the group VIB metal compound may be one or more selected from water-soluble molybdates, paramolybdates, tungstates, metatungstates and ethyl metatungstates, and the group VIII metal compound may be one or more selected from water-soluble nitrates, carbonates, chlorides, sulfates and acetates of cobalt and/or nickel.

The carrier is not particularly limited in the present invention, and may be any of various carriers commonly used in the art, and may be commercially available or may be prepared by any of the methods known in the art, and in order to further improve the desulfurization activity and selectivity of the hydrogenation catalyst, it is preferable that the carrier is a heat-resistant inorganic oxide.

Preferably, the heat-resistant inorganic oxide is selected from one or more of alumina, silica, titania, magnesia, silica-alumina, silica-magnesia, alumina-zirconia, silica-thoria, silica-beryllia, silica-titania, silica-zirconia, titania-zirconia, silica-alumina-thoria, silica-alumina-titania, silica-alumina-magnesia, silica-alumina-zirconia, most preferably alumina.

In the present invention, the concentration of the group VIB metal compound in the group VIB metal compound-containing solution is selected from a wide range, and may be, for example, from 0.05 to 1.5mol/L, more preferably from 0.12 to 1.12mol/L, and still more preferably from 0.12 to 0.9 mol/L.

The impregnation conditions in the step (1) are not particularly limited in the present invention, and may be, for example, 4 to 8 hours at room temperature.

The relative amounts of the carrier and the solution containing the group VIB metal compound are not particularly limited in the present invention, and can be determined by a person skilled in the art by conventional technical means, for example, the amount of the solution containing the group VIB metal compound can be determined according to the water absorption of the carrier.

In the present invention, the solid material of step (2) can be obtained by drying and optionally calcining the mixed material obtained by the impregnation of step (1), and the manner of drying and calcining is not particularly limited and can be performed in a conventional manner in the art. Preferably, the solid material in the step (2) is obtained by roasting. The roasting conditions are preferably as follows: the roasting temperature is 350-600 ℃, preferably 400-500 ℃, and the roasting time is 2-10 hours, preferably 2-6 hours.

In the invention, as long as the VIB group metal and the VIII group metal are impregnated and vulcanized step by step, the hydrogenation catalyst has higher hydrogenation and mercaptan removal activity and selectivity under a milder condition, so that the first vulcanization and the second vulcanization are not particularly limited.

Preferably, the first sulfidation in step (2) is such that the group VIB metal in the green catalyst has a degree of sulfidation above 50%, preferably in the range 55 to 75%, more preferably in the range 60 to 70%, as measured by X-ray photoelectron spectroscopy. When the sulfidation degree of the semi-finished catalyst is too low after the first sulfidation, the delayed sulfidation effect of the VIII group metal is weak in the second sulfidation process, and the formation of the Co (Ni) -Mo (W) -S active phase is not easy to occur, and when the sulfidation degree of the semi-finished catalyst is higher after the first sulfidation, it is indicated that a more stable sulfide of the VIB group metal is formed, and the auxiliary effect is lower even if the VIII group metal is introduced subsequently. The catalyst has better activity and selectivity in hydrodemercaptan removal by adopting the preferred mode.

In the present invention, unless otherwise specified, the sulfidation degree of the group VIB metal refers to the percentage of the total amount of the positive tetravalent group VIB metal element and the group VIB metal element, and the total amount of the positive tetravalent group VIB metal element and the group VIB metal element can be calculated according to the X-ray photoelectron spectroscopy analysis result, specifically referring to the qiume article (X-ray photoelectron spectroscopy method for studying the chemical state of the active element in the hydrodesulfurization catalyst [ J-J]And petroleum science and newspaper: petroleum processing, 2011, 27 (4): 638-642). For example, for cobalt molybdenum catalysts, the degree of molybdenum sulfidation is defined as Mo⁴⁺As a percentage of the total Mo.

In the present invention, the first vulcanization mode is not particularly limited, and may be dry (gas phase) vulcanization or wet (liquid phase) vulcanization, and when wet vulcanization is employed, it is preferable to obtain a semi-finished catalyst by drying the product obtained after the first vulcanization.

According to the invention, preferably, the first vulcanization is a dry (gas phase) vulcanization. The adoption of the preferred embodiment is more beneficial to preparing a cleaner semi-finished catalyst, so that the semi-finished catalyst does not contain impurities, and is more beneficial to the subsequent vulcanization of the VIII group metal and the formation of the Co (Ni) -Mo (W) -S active phase, on the other hand, the dry vulcanization provides a more stable hydrogen sulfide source, and is more beneficial to the subsequent formation of a more complete Co (Ni) -Mo (W) -S active phase, and further the hydrogenation sweetening activity and the selectivity of the catalyst are improved.

According to a preferred embodiment of the invention, said first vulcanization embodiment comprises: carrying out a first contact reaction on a sulfur-containing medium and the solid material obtained in the step (1).

According to a preferred embodiment of the present invention, the sulfur-containing medium is a mixed gas containing hydrogen and hydrogen sulfide, preferably, the mixed gas has a hydrogen sulfide content of 0.1 to 10 vol%, a hydrogen content of 90 to 99.9 vol%, further preferably, a hydrogen sulfide content of 1 to 5 vol%, a hydrogen content of 95 to 99 vol%, more preferably, a hydrogen sulfide content of 1 to 3 vol%, and a hydrogen content of 97 to 99 vol%.

In the present invention, the mixed gas may further contain an inert gas, and preferably, the mixed gas contains 0.1 to 10 vol% of hydrogen sulfide, 10 to 30 vol% of hydrogen, and 60 to 89.9 vol% of an inert gas, and further preferably, contains 1 to 3 vol% of hydrogen sulfide, 20 to 30 vol% of hydrogen, and 67 to 79 vol% of an inert gas.

In the present invention, the inert gas may be one or more selected from nitrogen, argon, helium, carbon dioxide and water vapor, preferably one or more selected from nitrogen, argon and helium, and more preferably nitrogen.

The first contact reaction of the present invention is widely selected, and preferably, the conditions of the first contact reaction include: the temperature is 200-^-1(ii) a Further preferably, the temperature is 230-^-1(ii) a More preferably, the temperature is 250-350 ℃, the pressure is 0.1-4.0MPa, the time is 5-10h, and the volume space velocity of the mixed gas is 500-1000h^-1。

In the present invention, the volume space velocity of the mixed gas represents the ratio of the flow rate (in mL/h) of the mixed gas to the volume (in mL) of the catalyst in a standard state.

According to the method provided by the present invention, preferably, the method further comprises: before the step (3), passivating the semi-finished catalyst, wherein a layer of oxygen is adsorbed on the surface of the metal sulfide of the passivated catalyst, so that the catalyst can complete the impregnation step and the drying step of the VIII group metal in the air atmosphere, and in the second step of sulfurization in the step (4), the oxygen on the surface of the metal sulfide can be removed at a lower temperature and changed into sulfide again in the presence of hydrogen and sulfide.

According to a preferred embodiment of the invention, the passivation is carried out by contacting the semifinished catalyst with a gas mixture comprising an inert gas and oxygen, preferably the oxygen content of the gas mixture comprising inert gas and oxygen is 0.05 to 30% by volume, preferably 0.1 to 21% by volume. The inert gas is preferably nitrogen.

The semi-finished catalyst is contacted with the mixed gas containing inert gas and oxygen (i.e. passivated) under the conditions of room temperature to 100 ℃, 1 to 48 hours of time, 0.1 to 10MPa of pressure and 50 to 2000 hours of volume space velocity of the mixed gas^-1(ii) a The preferred passivation temperature is 30-70 ℃, the pressure is 0.1-5MPa, the time is 1-12 hours, and the volume space velocity of the mixed gas is 100-^-1。

In the present invention, the volume space velocity of the mixed gas in the passivation step means the ratio of the flow rate of the mixed gas (in mL/h) to the volume of the catalyst (in mL) in the standard state.

According to a preferred embodiment of the present invention, the group VIII metal compound is added in step (3) in such an amount that the molar ratio of said group VIII metal compound to said group VIB metal compound, calculated as metal elements, is from 0.4 to 1.2: 1, more preferably 0.5 to 1: 1.

the impregnation conditions in the step (3) are not particularly limited in the present invention, and may be, for example, impregnation at room temperature for 4 to 8 hours.

In order to further improve the mercaptan removal activity and selectivity of the catalyst, it is preferable that the solution containing the group VIII metal compound in step (3) further contains an organic complexing agent. The presence of the organic complexing agent enables the size of the metal active phase to be controlled to some extent and promotes the group VIII metal to exert an adjuvant effect.

In the present invention, the molar ratio of the organic complexing agent to the group VIB metal compound calculated as the metal element may be from 0.5 to 1.5: 1, preferably 0.6 to 1.2: 1.

the type of the organic complexing agent is not particularly limited in the present invention, and may be various organic complexing agents used in the preparation process of the hydrogenation catalyst, and for example, the organic complexing agent may be at least one selected from the group consisting of citric acid, ethylenediaminetetraacetic acid (EDTA), ethylene glycol, glycerol, and nitrilotriacetic acid.

In the present invention, the second sulfurization mode is not particularly limited, and may be dry (gas phase) sulfurization or wet (liquid phase) sulfurization, preferably wet sulfurization, and the size of the metal active phase can be effectively controlled by this preferred embodiment, thereby further improving the activity and selectivity of the catalyst.

According to a preferred embodiment of the present invention, it is preferred that the second vulcanization embodiment comprises: and (3) carrying out second contact reaction on the vulcanized oil containing the vulcanizing agent and the solid material obtained in the step (3) in the presence of hydrogen.

In the present invention, the vulcanizing agent is selected from a wide range, and may be, for example, at least one of elemental sulfur, inorganic sulfur compounds, mercaptans, sulfides, disulfides and polysulfides, which are generally used in the art. The present invention is not particularly limited as long as sufficient vulcanization of the metal is satisfied, and for example, carbon disulfide, dimethyl disulfide (DMDS), or the like can be used.

The content of the vulcanizing agent in the present invention is not particularly limited as long as sufficient vulcanization of the catalyst is satisfied, and the content of the vulcanizing agent is preferably 2 to 10 parts by weight, and more preferably 2 to 5 parts by weight, relative to 100 parts by weight of the vulcanizing oil containing the vulcanizing agent.

In the present invention, the selection range of the vulcanized oil is wide, and for example, the vulcanized oil can be selected from at least one of gasoline distillate, aviation kerosene distillate and diesel oil distillate, preferably selected from at least one of straight-run gasoline distillate, straight-run aviation kerosene distillate and straight-run diesel oil distillate, and more preferably selected from straight-run gasoline distillate; the vulcanized oil can also be selected from at least one of organic hydrocarbon substances with carbon number of 5-18, preferably from at least one of organic hydrocarbon substances with carbon number of 6-12, and more preferably cyclohexane and/or n-heptane.

According to a preferred embodiment of the present invention, the conditions of the second contact reaction include: the temperature is 200-^-1The volume ratio of hydrogen to oil is 10-1000; further preferably, the temperature is 300-^-1The volume ratio of hydrogen to oil is 50-1000; even more preferably, warmThe temperature is 300-^-1The volume ratio of hydrogen to oil is 200-900.

The hydrogenation catalyst prepared by the preparation method has excellent activity and selectivity for removing mercaptan, so the invention also provides the hydrogenation catalyst prepared by the preparation method.

The hydrogenation catalyst according to the present invention has a carrier content of 70 to 97 wt%, preferably 79 to 97 wt%, based on the total amount of the catalyst; the group VIII metal is present in an amount of 1 to 10 wt.%, preferably 1 to 6 wt.%, and the group VIB metal in an amount of 2 to 20 wt.%, preferably 2 to 15 wt.%, calculated on the respective oxide.

The invention also provides the application of the hydrogenation catalyst prepared by the preparation method in the hydrogenation and mercaptan removal of gasoline.

The hydrogenation catalyst prepared by the preparation method is applied to the process of gasoline hydrogenation sweetening, and can effectively remove the mercaptan in the gasoline under the condition of less octane number loss.

The following detailed description is provided for the purpose of illustrating the embodiments and the advantageous effects thereof, and is intended to help the reader to clearly understand the spirit of the present invention, but not to limit the scope of the present invention.

In the following examples, the metal content of the catalyst was measured by X-ray fluorescence spectroscopy (XRF) using a ZSX-100e X-ray fluorescence spectrometer at a current of 50mA and a voltage of 50kV using an Rh target.

The degree of sulfidation of the main agent Mo (or W) in the catalyst is determined by X-ray photoelectron spectroscopy (XPS), wherein, the degree of sulfidation is obtained by XPS data processing, and the specific processing method can be seen in literature X-ray photoelectron spectroscopy to research the chemical state [ J ] of the active element in the hydrodesulfurization catalyst, and the petro report: petroleum processing, 2011, 27 (4): 638-642. Among them, X-ray photoelectron spectroscopy (XPS) was performed on an ESCA Lab 250 type X-ray photoelectron spectrometer (VG, england) obtained under the conditions of Al K α as a radiation source, 0.5eV as a resolution, and C1s binding energy (Eb =285.0eV) with carbon contamination as an internal standard.

In the following examples, the support was a clover type alumina strip support having a circumscribed circle diameter of 1.4 mm, available from Changling catalyst division.

Example 1

(1) Weighing 17.4g of ammonium heptamolybdate, adding deionized water to prepare 110mL of aqueous solution, soaking 100g of carrier by using the aqueous solution for 6h, then drying at 120 ℃ for 4h, and roasting at 420 ℃ for 4h to obtain Mo/Al₂O₃；

(2) For Mo/Al₂O₃Carrying out dry vulcanization, wherein the specific conditions comprise: by means of H₂S and H₂Mixed gas (H) of (2)₂S volume content of 1%) as a sulfur-containing medium, with Mo/Al₂O₃The reaction is carried out for 6h at 300 ℃ and 1.6MPa, and the volume space velocity of the mixed gas is 1000h^-1To obtain a semi-finished catalyst B-1;

(3) passivating the semi-finished product catalyst B-1, specifically: using 5 vol% O₂+95 vol% N₂Blowing the semi-finished catalyst for 6h at 50 ℃ and 0.6MPa, wherein the volume space velocity of air is 100h^-1；

(4) Weighing 11.8g of cobalt nitrate and 21.55g of EDTA, adding deionized water to prepare 80mL of aqueous solution, dipping the passivated solid product in the step (3), and drying at 120 ℃ for 4 hours;

(5) and (3) carrying out wet vulcanization on the solid product obtained by drying in the step (4), specifically: in the presence of hydrogen, the solid product obtained by drying in the step (4) is in contact reaction with cyclohexane containing 5 weight percent of carbon disulfide at 300 ℃ and 1.6MPa for 6h, and the volume space velocity of the hydrogen is 9000h^-1And when the volume ratio of hydrogen to oil is 900, cooling the reaction temperature to room temperature to obtain the hydrogenation catalyst S-1.

The results of analyzing the contents of the components of the hydrogenation catalyst S-1 are shown in Table 1.

The semi-finished catalyst B-1 was prepared by repeating the steps (1) and (2), and the semi-finished catalyst B-1 was subjected to XPS analysis, the analysis results of which are shown in Table 1.

Example 2

(1) 24.5g of ammonium metatungstate was weighed,adding deionized water to prepare 110mL of aqueous solution, soaking 100g of carrier with the aqueous solution for 4h, drying at 120 ℃ for 4h, and roasting at 420 ℃ for 4h to obtain W/Al₂O₃；

(2) For W/Al₂O₃Carrying out dry vulcanization, wherein the specific conditions comprise: by means of H₂S、H₂And N₂Mixed gas (H) of (2)₂S content 1% by volume, H₂20% by volume) as a sulfur-containing medium, with W/Al₂O₃The reaction is carried out for 10 hours at 320 ℃ and 2MPa, and the volume space velocity of the mixed gas is 800 hours^-1To obtain a semi-finished catalyst B-2;

(3) passivating the semi-finished product catalyst B-2, specifically: blowing the semi-finished catalyst with air at 30 ℃ and 2.5MPa for 3h, 5 vol% O₂+95 vol% N₂The volume space velocity of the reactor is 900h^-1；

(4) Weighing 11.7g of nickel nitrate and 14.09g of nitrilotriacetic acid, adding deionized water to prepare 78mL of aqueous solution, dipping the passivated solid product obtained in the step (3), and drying at 120 ℃ for 4 hours;

(5) and (3) carrying out wet vulcanization on the solid product obtained by drying in the step (4), specifically: in the presence of hydrogen, the solid product obtained by drying in the step (4) is in contact reaction with straight-run gasoline distillate oil containing 3 weight percent of carbon disulfide for 10 hours at 320 ℃ and 2MPa, and the volume space velocity of the hydrogen is 5000 hours^-1And when the volume ratio of the hydrogen to the oil is 400, cooling the reaction temperature to room temperature to obtain the hydrogenation catalyst S-2.

The results of analyzing the contents of the components of the hydrogenation catalyst S-2 are shown in Table 1.

The semi-finished catalyst B-2 was prepared by repeating the steps (1) and (2), and the semi-finished catalyst B-2 was subjected to XPS analysis, the analysis results of which are shown in Table 1.

Example 3

(1) Weighing 17.4g of ammonium heptamolybdate, adding deionized water to prepare 110mL of aqueous solution, soaking 100g of carrier with the aqueous solution for 4h, drying at 120 ℃ for 4h, and roasting at 420 ℃ for 4h to obtain Mo/Al₂O₃；

(2) For Mo/Al₂O₃Carrying out dry vulcanization, in particularThe conditions include: by means of H₂S and H₂Mixed gas (H) of (2)₂S volume content of 3%) as a sulfur-containing medium, with Mo/Al₂O₃The reaction is carried out for 4 hours at 350 ℃ and 2MPa, and the volume space velocity of the mixed gas is 500 hours^-1To obtain a semi-finished catalyst B-3;

(3) passivating the semi-finished product catalyst B-3, specifically: with 2.5 vol.% O₂+97.5 vol% N₂Purging the semi-finished catalyst at 70 deg.C and 1MPa for 10h, 2.5 vol% O₂+97.5 vol% N₂The volume space velocity of is 400h^-1；

(4) Weighing 11.7g of nickel nitrate and 14.09g of nitrilotriacetic acid, adding deionized water to prepare 80mL of aqueous solution, dipping the passivated solid product obtained in the step (3), and drying at 120 ℃ for 4 hours;

(5) and (3) carrying out wet vulcanization on the solid product obtained by drying in the step (4), specifically: in the presence of hydrogen, the solid product obtained by drying in the step (4) is in contact reaction with straight-run gasoline distillate containing 2 weight percent of dimethyl disulfide (DMDS) at 350 ℃ and 3MPa for 5h, and the volume space velocity of hydrogen is 3000h^-1And when the volume ratio of hydrogen to oil is 500, cooling the reaction temperature to room temperature to obtain the hydrogenation catalyst S-3.

The results of analyzing the contents of the components of the hydrogenation catalyst S-3 are shown in Table 1.

The semi-finished catalyst B-3 was prepared by repeating the steps (1) and (2), and the semi-finished catalyst B-3 was subjected to XPS analysis, the analysis results of which are shown in Table 1.

Example 4

The process of example 1 is followed, except that step (5) employs the same dry vulcanization as step (2), specifically:

(2) For Mo/Al₂O₃Carrying out dry vulcanization, wherein the specific conditions comprise: by means of H₂S and H₂Mixed gas (H) of (2)₂S content 1%) asSulfur-containing media, with Mo/Al₂O₃The reaction is carried out for 6h at 300 ℃ and 1.6MPa, and the volume space velocity of the mixed gas is 1000h^-1To obtain a semi-finished catalyst B-1;

(3) passivating the semi-finished product catalyst B-1, specifically: blowing the semi-finished catalyst for 6h at 50 ℃ and 0.6MPa by using air, wherein the volume space velocity of the air is 100h^-1；

(5) carrying out dry vulcanization on the solid product obtained by drying in the step (4), and specifically: drying the solid product obtained in the step (4) and H₂S and H₂Mixed gas (H) of (2)₂S volume content of 1%) at 300 deg.C and 1.6MPa for 6h, and the volume space velocity of mixed gas is 1000h^-1And when the reaction temperature is reduced to room temperature, obtaining the hydrogenation catalyst S-4.

The results of analyzing the contents of the components of the hydrogenation catalyst S-4 are shown in Table 1.

Example 5

The process of example 1 is followed, except that step (2) is carried out using the same wet vulcanization as step (5), in particular:

(2) For Mo/Al₂O₃Carrying out wet vulcanization, wherein the specific conditions comprise: in the presence of hydrogen, Mo/Al₂O₃Reacting with cyclohexane containing 5 wt% of carbon disulfide at 300 ℃ and 1.6MPa for 6h, wherein the volume space velocity of hydrogen is 9000h^-1The volume ratio of hydrogen to oil is 900 to obtain a semi-finished catalyst B-5;

(3) passivating the semi-finished product catalyst B-5, specifically: blowing the semi-finished catalyst for 6h at 50 ℃ and 0.6MPa by using air, wherein the volume space velocity of the air is 100h^-1；

(5) and (3) carrying out wet vulcanization on the solid product obtained by drying in the step (4), specifically: in the presence of hydrogen, the solid product obtained by drying in the step (4) is in contact reaction with cyclohexane containing 5 weight percent of carbon disulfide at 300 ℃ and 1.6MPa for 6h, and the volume space velocity of the hydrogen is 9000h^-1And when the volume ratio of hydrogen to oil is 900, cooling the reaction temperature to room temperature to obtain the hydrogenation catalyst S-5.

The results of analyzing the contents of the components of the hydrogenation catalyst S-5 are shown in Table 1.

The semi-finished catalyst B-5 was prepared by repeating the steps (1) and (2), and the semi-finished catalyst B-5 was subjected to XPS analysis, the analysis results of which are shown in Table 1.

Example 6

The process of example 1 was followed except that the specific conditions for the dry vulcanization of step (2) included: by means of H₂S and H₂Mixed gas (H) of (2)₂S volume content of 1%) as a sulfur-containing medium, with Mo/Al₂O₃The reaction is carried out for 4 hours at 250 ℃ and 1.6MPa, and the volume space velocity of the mixed gas is 1000 hours^-1To obtain the hydrogenation catalyst S-6.

The results of analyzing the contents of the components of the hydrogenation catalyst S-6 are shown in Table 1.

And (3) repeating the step (1) and the step (2) to obtain a semi-finished catalyst B-6, and performing XPS analysis on the semi-finished catalyst B-6, wherein the analysis results are shown in Table 1.

Example 7

The process described in example 1 was followed except that calcination at 420 ℃ for 4 hours was not included in step (1). The semi-finished catalyst B-7 and the hydrogenation catalyst S-7 were obtained, and the results of XPS analysis of the semi-finished catalyst B-7 and analysis of the content of the components of the hydrogenation catalyst S-7 are shown in Table 1.

Comparative example 1

(1) 17.4g of ammonium heptamolybdate, 11.8g of cobalt nitrate and 21.55g of EDTA were weighed, deionized water was added to prepare 110mL of an aqueous solution, 100g of the support was impregnated with the aqueous solution for 6 hours, and then the mixture was heated at 120 ℃ to obtain a solutionDrying for 4h, and roasting at 420 ℃ for 4h to obtain CoMo/Al₂O₃；

(2) For CoMo/Al₂O₃Carrying out dry vulcanization, wherein the specific conditions comprise: by means of H₂S and H₂Mixed gas (H) of (2)₂S volume content of 1%) as a sulfur-containing medium, with CoMo/Al₂O₃The reaction is carried out for 6h at 300 ℃ and 1.6MPa, and the volume space velocity of the mixed gas is 1000h^-1To obtain the hydrogenation catalyst D-1.

The results of analyzing the contents of the components of the hydrogenation catalyst D-1 are shown in Table 1.

Comparative example 2

(1) Weighing 17.4g of ammonium heptamolybdate and 11.8g of cobalt nitrate, adding deionized water to prepare 110mL of aqueous solution, soaking 100g of carrier by using the aqueous solution for 6h, then drying at 120 ℃ for 4h, and roasting at 420 ℃ for 4h to obtain CoMo/Al₂O₃；

(2) For CoMo/Al₂O₃Carrying out wet vulcanization, wherein the specific conditions comprise: in the presence of hydrogen, CoMo/Al₂O₃Reacting with cyclohexane containing 5 wt% of carbon disulfide at 300 ℃ and 1.6MPa for 6h, wherein the volume space velocity of hydrogen is 9000h^-1And the volume ratio of hydrogen to oil is 900 to obtain the hydrogenation catalyst D-2.

The results of analyzing the contents of the components of the hydrogenation catalyst D-2 are shown in Table 1.

TABLE 1 analysis of the component contents of the hydrogenation catalyst and the degree of sulfidation of the semi-finished catalyst

Test examples

In this test example, the mercaptan removal activity and selectivity of the hydrogenation catalyst provided in the inventive example and the hydrogenation catalyst provided in the comparative example were evaluated in accordance with the following methods, and the results are shown.

Evaluation of catalyst on a Small fixed bed hydrogenation reactor Using a solution containing 1-hexene, octane, and 100. mu.g/g 1-heptanethiol (volume ratio of 1-hexene to octane: 20: 80) as the starting MaterialPerformance of the catalyst. The reaction conditions are as follows: 1.6MPa, 260 ℃, 400 of hydrogen-oil volume ratio and 8h of mass space velocity^-1. After the reaction is stable for 3h, sampling and analyzing after the reaction is carried out for 4 h. The samples were analyzed by GC-MASS and the results are shown in Table 2. Wherein, the olefin saturation rate HYD, the removal rate X of heptamercaptan (for explaining the mercaptan removal activity), the sulfur concentration Y of hexanethiol and the formation factor S of hexanethiol (for explaining the mercaptan removal selectivity, the lower the S, the better the mercaptan removal selectivity) of the reaction are calculated according to the following formula:

HYD ═ 100%

X ═ raw heptanethiol concentration-product heptanethiol concentration)/raw heptanethiol concentration X100%

Y = hexanethiol percent concentration in product X0.2712X 10000

S=Y/（100-HYD）

TABLE 2

Examples	HYD/%	X/%	Y/（μg/g）	S
					Example 1	75.37	100	7.1	0.288
Example 2	75	100	12.3	0.492
					Example 3	74.36	100	11.2	0.437
Example 4	76.5	98	13.0	0.553
					Example 5	76.3	99	15.2	0.641
Example 6	77.5	99	18.3	0.813
					Example 7	76	100	12.3	0.513
Example 8	75.9	100	13.5	0.560
					Comparative example 1	79	96	21.5	1.024
Comparative example 2	78.5	97	20.4	0.949

The results in tables 1 and 2 show that, compared with the hydrogenation catalyst prepared by the conventional method, the hydrogenation catalyst provided by the invention can realize effective removal of mercaptan even if the hydrogenation catalyst has similar metal composition under milder reaction conditions, and has low olefin saturation rate and low mercaptan generation factor S, which indicates that the hydrogenation catalyst prepared by the method provided by the invention has high mercaptan removal activity and good selectivity, and the preparation method provided by the invention has incomparable superiority compared with the conventional impregnation method. As can be seen from a comparison of example 1 with examples 4-6, the performance of the hydrogenation catalyst can be further improved by employing the preferred mode of sulfidation of the present invention.

The preferred embodiments of the present invention have been described in detail, however, the present invention is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications are within the protective scope of the present invention.

It should be noted that the various features described in the above embodiments may be combined in any suitable manner without departing from the scope of the invention. The invention is not described in detail in order to avoid unnecessary repetition.

In addition, any combination of the various embodiments of the present invention is also possible, and the same should be considered as the disclosure of the present invention as long as it does not depart from the spirit of the present invention.

Claims

1. A preparation method of a hydrogenation catalyst is characterized by comprising the following steps:

(4) performing second vulcanization on the solid material obtained in the step (3);

wherein, in the step (2), the first sulfurization is carried out to ensure that the sulfurization degree of the VIB group metal in the semi-finished catalyst is 55-75%, and the sulfurization degree is measured by X-ray photoelectron spectroscopy; wherein the second disulfide embodiment comprises: in the presence of hydrogen, carrying out a second contact reaction on vulcanized oil containing a vulcanizing agent and the solid material obtained in the step (3);

embodiments of the first cure include: carrying out a first contact reaction on a sulfur-containing medium and the solid material obtained in the step (1); the sulfur-containing medium is a mixed gas containing hydrogen and hydrogen sulfide;

the preparation method also comprises the following steps: before the step (3), passivating the semi-finished catalyst in a manner of contacting the semi-finished catalyst with a mixed gas containing inert gas and oxygen;

the degree of sulfidation refers to the percentage of positive tetravalent group VIB metal elements to the total of group VIB metal elements.

2. The preparation method according to claim 1, wherein in the step (1), the concentration of the group VIB metal compound in the solution is 0.05-1.5 mol/L.

3. The production method according to claim 1 or 2, wherein the mixed gas has a hydrogen sulfide content of 0.1 to 10 vol% and a hydrogen content of 90 to 99.9 vol%.

4. The production method according to claim 1 or 2, wherein the mixed gas contains an inert gas; in the mixed gas, the content of hydrogen sulfide is 0.1-10 vol%, the content of hydrogen is 10-30 vol%, and the content of inert gas is 60-89.9 vol%.

5. The production method according to claim 1 or 2, wherein the conditions of the first contact reaction include: the temperature is 200-^-1。

6. The production method according to claim 1 or 2, wherein the content of oxygen in the mixed gas containing an inert gas and oxygen is 0.05 to 30% by volume.

7. The production method according to claim 6, wherein the content of oxygen in the mixed gas containing an inert gas and oxygen is 0.1 to 21% by volume.

8. The preparation method of claim 6, wherein the passivation temperature is between room temperature and 100 ℃, the pressure is between 0.1 and 10MPa, the time is between 1 and 48 hours, and the volume space velocity of the mixed gas is between 50 and 2000h^-1。

9. The preparation method as claimed in claim 6, wherein the passivation temperature is 30-70 ℃, the pressure is 0.1-5MPa, the time is 1-12 h, and the volume space velocity of the mixed gas is 100-^-1。

10. The preparation method according to claim 1, wherein the molar ratio of the group VIII metal compound to the group VIB metal compound is 0.4-1.2: 1.

11. the preparation method according to claim 10, wherein the solution containing the group VIII metal compound in step (3) further contains an organic complexing agent, and the molar ratio of the organic complexing agent to the group VIB metal compound calculated by the metal elements is 0.5-1.5: 1.

12. the production method according to claim 11, wherein the organic complexing agent is selected from at least one of citric acid, ethylenediaminetetraacetic acid, ethylene glycol, glycerol, and nitrilotriacetic acid.

13. The production method according to claim 1, wherein the vulcanizing agent is selected from at least one of elemental sulfur, inorganic sulfur compounds, mercaptans, sulfides, disulfides, and polysulfides; the vulcanized oil is at least one of gasoline distillate, aviation kerosene distillate and diesel oil distillate.

14. The production method according to claim 13, wherein the vulcanizing agent is contained in an amount of 2 to 10 parts by weight relative to 100 parts by weight of the vulcanizing oil containing a vulcanizing agent.

15. The production method according to claim 13, wherein the vulcanizing agent is contained in an amount of 2 to 5 parts by weight relative to 100 parts by weight of the vulcanizing oil containing a vulcanizing agent.

16. The production method according to claim 1, wherein the conditions of the second contact reaction include: the temperature is 200-^-1The volume ratio of hydrogen to oil is 10-1000.

17. The preparation method according to claim 1 or 2, wherein the support is a refractory inorganic oxide, the group VIB metal is molybdenum and/or tungsten; the group VIII metal is cobalt and/or nickel.

18. A hydrogenation catalyst produced by the production method according to any one of claims 1 to 17.

19. The hydrogenation catalyst according to claim 18, wherein the carrier is present in an amount of 70 to 97 wt.%, based on the total amount of the catalyst; the content of group VIII metal is 1-10 wt.% and the content of group VIB metal is 2-20 wt.% calculated on the respective oxides.

20. The hydrogenation catalyst according to claim 18, wherein the carrier is present in an amount of 79 to 97 wt.%, based on the total amount of the catalyst; the content of group VIII metal is 1-6 wt.% and the content of group VIB metal is 2-15 wt.% calculated on the respective oxides.

21. Use of a hydrogenation catalyst according to claim 18 or 19 or 20 for the hydrodesulphurisation of gasoline.