Anti-poisoning phosphide supported catalyst, preparation method thereof and application of anti-poisoning phosphide supported catalyst in preparation of aviation kerosene from cottonseed oil

Abstract

The invention relates to an anti-poisoning phosphide supported catalyst, a preparation method thereof and an application of the anti-poisoning phosphide supported catalyst in preparation of aviation kerosene from cottonseed oil, transition metal salt and an inorganic phosphorus source are supported on a zeolite molecular sieve, and after calcination reduction, the zeolite molecular sieve is treated by an electron regulator to obtain the anti-poisoning phosphide supported catalyst. And generating a metal oxide with an electronic regulation function on the surface of the transition metal phosphide to form the anti-poisoning phosphide supported catalyst. According to the catalyst, transition metal phosphide is adopted as an active center, so that the catalyst has relatively high catalytic activity; meanwhile, the defect that pure non-noble metal provides too many strong acid sites is avoided through the treatment method, generation of non-condensable gas is reduced, the function of resisting poisoning of phosphorus and sulfur compounds is achieved, and the service life is remarkably prolonged.

Description

Technical Field

[0001] The invention belongs to the technical field of catalysts, and in particular relates to a catalyst containing phosphorus, specifically a poison-resistant phosphide-supported catalyst, a preparation method thereof, and an application of the catalyst in preparing aviation kerosene from cottonseed oil. Background Art

[0002] Bio-jet fuel can reduce carbon dioxide emissions by 80% over its entire life cycle, and plays an important role in energy conservation and emission reduction in the aviation industry. Cotton is widely grown in my country, with large-scale production and can be collected mechanically. The cottonseed oil yield is high after the cotton fiber is removed, so it is very feasible to use cottonseed oil as a raw material for preparing bio-jet fuel.

[0003] The hydroisomerization and cracking reactions of vegetable oils are key reactions in the preparation of bio-jet fuel, and the catalysts used are mostly precious metal catalysts supported by molecular sieve carriers. This type of catalyst is a bifunctional catalyst that can simultaneously achieve isomerization and cracking reactions of alkanes under the same reaction conditions. For example, in patent CN111701623B, the molecular sieve is subjected to pore expansion and sulfonation treatment, and after being composited with alumina, it is loaded with active metals such as Pt, Pd, Ni, and Co, and a series of additives are introduced for long-chain alkane hydrocracking and isomerization, with good results; in CN118002194A, the 4A or 5A molecular sieve impregnated with Pt is encapsulated in a twelve-membered ring or fourteen-membered ring zeolite for the preparation of bio-jet fuel, with stable catalyst activity and a structure that is not prone to collapse; in patent CN 114522716 A, the synergistic effect of nickel and the second transition metal is used to prepare a bimetallic supported catalyst loaded on an acidic carrier by alkaline precipitation, which is used for the hydrodeoxygenation and cracking and isomerization of palm oil, with a bio-jet fuel yield of up to 60% and reduced carbon loss.

[0004] Transition metal phosphides have a special crystal structure and strong electron transfer ability, so they have strong redox properties. In recent years, they have been widely used in the fields of photoelectrocatalytic hydrogen production and catalytic hydrogenation. In this type of catalyst, phosphate is generally selected to introduce P into the catalyst, and P can react with transition metals to generate different phosphides. However, there are few reports on transition metal phosphide-supported catalysts in the preparation of bio-jet fuel using vegetable oil as raw material. There are two main reasons for this. First, the interaction between transition metal phosphides and carriers affects the existence form and catalytic activity of transition metal phosphides. The production of bio-jet fuel using vegetable oil as raw material requires a catalyst with strong isomerization ability and weak acidity. Zeolite molecular sieves have become the preferred catalyst carrier for this type of reaction because of their specific pore structure. However, most molecular sieves are aluminosilicates and aluminum phosphates. Taking Ni2P as an example, the common synthesis method of transition metal phosphides is: (1) Ni(NO3)2 and (NH4)2HPO4 or NH4H2PO4 are used as precursors to prepare Ni2P in a H2 atmosphere and at high temperature; (2) Hypophosphite is used as a phosphorus source, dissolved with a metal hydrochloride, dried at 60°C, placed in an inert gas environment, and reduced at 180-400°C to obtain Ni2P. When these two methods are combined with zeolite molecular sieves, they will react with the carrier to generate substances other than metal phosphides. For example, in a molecular sieve with SiO2 as the main component, Ni exists in the form of Ni-OP and P exists in the form of PO4 3- 、P2O7 4- and (PO 3- ) n In the molecular sieve containing Al2O3, due to the strong interaction between P and Al2O3, most of the P exists in the form of AlPO4, and a small part exists in the form of P x O y or PO x n-In the form of Ni, Al2O3 exists, while Ni exists in the form of Ni-O. In addition, due to the surface defects of Al2O3, Ni species may enter the surface vacancies to form a NiAl2O4 spinel phase on the surface. Therefore, more excess P is required in the precursor, and a higher temperature is required for the precursor to be fully reduced. If the catalyst carrier is an aluminum phosphate molecular sieve (SAPO-11, SAPO-34, etc.), the phase composition and catalytic activity of the synthesized transition metal phosphide become extremely unstable. Second, the phosphorus-sulfur compounds in the vegetable oil poison the transition metal phosphide, causing the phase composition of the phosphide to change and the catalyst to deactivate quickly. Compared with pure heptadecane and octadecane mixtures, actual animal and plant oils and their corresponding hydrodeoxygenation products contain phosphorus and sulfur compounds. However, even at the ppm level, they are still easily adsorbed and reacted on the surface of the transition metal phosphide under hydrogen and high temperature, resulting in changes in the phosphide phase. For example, Ni2P, which has strong catalytic activity, will generate other inactive phosphides such as NiP and NiP3 when reacting with phosphorus at high temperatures, and will generate sulfates when reacting with sulfur compounds, which greatly reduces the catalytic activity. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a poison-resistant phosphide-supported catalyst and a preparation method thereof, and application of the catalyst in preparing aviation kerosene from cottonseed oil.

[0006] The technical solution adopted by the present invention is: a method for preparing a poison-resistant phosphide-loaded catalyst, wherein a transition metal phosphide is loaded onto a molecular sieve, and after calcination and reduction, a metal oxide with an electron regulating function is generated on the surface of the transition metal phosphide to form a poison-resistant phosphide-loaded catalyst.

[0007] Preferably, the specific steps are as follows:

[0008] Step 1: Mix and stir the transition metal salt, inorganic phosphorus source and water, impregnate them onto the molecular sieve by an equal volume impregnation method, and dry them to obtain sample A;

[0009] Step 2: calcining sample A to obtain sample B;

[0010] Step 3: reducing sample B with hydrogen to obtain sample C;

[0011] Step 4: Disperse sample C in water, add it to 50-100°C, add an electronic regulator, stir the reaction, filter and dry the product to obtain a poison-resistant phosphide-supported catalyst.

[0012] Preferably, the electron modifier is one of La(NO3)3·6H2O, Ce(NO3)3·6H2O, SnCl2·2H2O;

[0013] Transition metal salts are Ni(NO3)2·6H2O, Co(NO3)2·6H2O, Fe(NO3)3·9H2O, (NH4)6Mo7O 24 4H2O, (NH4)6H2W 12 O 40 One of xH2O;

[0014] The inorganic phosphorus source is one or more of phosphoric acid, NH4H2PO4, and (NH4)2HPO4.

[0015] Preferably, the molecular sieve is a zeolite molecular sieve, and the zeolite molecular sieve is one of SAPO-11, SAPO-5, SAPO-18, SAPO-34, ZSM-48, USY, and beta.

[0016] Preferably, the silicon to aluminum molar ratio (SiO2 / Al2O3) of SAPO-11 is 0.2-0.8, the silicon to aluminum molar ratio of ZSM-48 is 50-100, the silicon to aluminum molar ratio of USY is 2-8, and the silicon to aluminum ratio of beta is 20-80.

[0017] Preferably, the mass ratio of zeolite molecular sieve to transition metal salt is 2.3-15, the mass ratio of zeolite molecular sieve to inorganic phosphorus source is 10.1-66.3, the molar ratio of transition metal salt to inorganic phosphorus source is 0.5-3; the mass ratio of electronic regulator to transition metal salt is 0.25-1.26.

[0018] Preferably, the calcination conditions in step 2 are calcination at 400-600°C for at least 2h, and a heating rate of 1-5°C / min;

[0019] In step 3, the reduction condition is that the minimum volume space velocity of hydrogen is 400h –1 , calcined at 500-800℃ for at least 3h, with a heating rate of 0.5-4℃ / min.

[0020] The invention discloses a method for preparing a poison-resistant phosphide-supported catalyst and obtains a poison-resistant phosphide-supported catalyst.

[0021] Application of poison-resistant phosphide-supported catalysts in the preparation of bio-jet fuel from vegetable oil.

[0022] Preferably, the process for hydroisomerization of cottonseed oil hydrodeoxygenation product to prepare bio-jet fuel is as follows:

[0023] Step 1: Load the catalyst into the constant temperature range of the continuous flow high pressure fixed bed reactor, and load a ceramic ring of at least 20 cm on the upper layer of the catalyst as a preheating layer;

[0024] Step 2: 40-100 wt % cottonseed oil hydrodeoxygenation (HDO) product-cyclohexane solution is pumped into the reactor by a pressure pump, wherein the liquid hourly space velocity of the mixed solution is 0.5-1.5 h –1 , the reaction temperature is 290-400℃, the hydrogen pressure is 1.5-4.0MPa, and the hydrogen-oil ratio is 400-1400; the condensed and collected product is the aviation kerosene component;

[0025] Step 3: After the reaction is completed, stop feeding first, then continue to purge with hydrogen for at least 1 hour, then cool down, and turn off the hydrogen after the temperature drops below 100°C.

[0026] The advantages and positive effects of the present invention are: using transition metal phosphides as active centers, having high catalytic activity and bio-jet fuel yield, and indicators such as freezing point, flash point, and viscosity are comparable to those of precious metal catalysts, such as platinum-based catalysts, while avoiding the disadvantage of pure non-precious metals providing more strong acid sites and reducing the generation of non-condensable gas;

[0027] By adjusting the appropriate ratio during the preparation process, the effect of the molecular sieve on the production of impurities when generating transition metal phosphides is minimized to ensure the catalytic activity of the phosphides. By grafting metal oxides on the surface of transition metal phosphides, phosphorus species in the crude oil are more difficult to combine with transition metal phosphides, achieving anti-poisoning. By adjusting the electron density of the active site, the reaction energy barrier is increased, thereby greatly extending the service life of the catalyst. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 : XPS spectrum of the 2P orbital of Ni in Example 1 (Cat-1);

[0029] Figure 2 : Example 1 life test effect diagram;

[0030] Figure 3 : Comparative Example 1 life test effect diagram. DETAILED DESCRIPTION

[0031] The embodiments of the present invention are described below with reference to the accompanying drawings.

[0032] The present invention relates to a poison-resistant phosphide supported catalyst and its preparation method and application. A transition metal salt and an inorganic phosphorus source are loaded onto a zeolite molecular sieve, and after calcination and reduction, an electronic regulator is used to generate a metal oxide with an electronic regulation function on the surface of the transition metal phosphide to form a poison-resistant phosphide supported catalyst. The catalyst uses the transition metal phosphide as an active center and can have a high catalytic activity. At the same time, the treatment method avoids the disadvantage of pure non-precious metals providing too many strong acid sites and reduces the generation of non-condensable gas.

[0033] The preparation method of the poison-resistant phosphide supported catalyst is as follows:

[0034] Step 1: After the transition metal salt, inorganic phosphorus source and water are mixed and stirred to dissolve, they are impregnated onto the zeolite molecular sieve by an equal volume impregnation method, and after thorough drying, sample A is obtained; the mass ratio of the zeolite molecular sieve to the transition metal salt is 2.3-15:1, the mass ratio of the zeolite molecular sieve to the inorganic phosphorus source is 10.1-66.3:1, and the molar ratio of the transition metal salt to the inorganic phosphorus source is 0.5-3:1; wherein the inorganic phosphorus source is one or more of phosphoric acid, NH4H2PO4, (NH4)2HPO4, and the transition metal salt is Ni(NO3)2·6H2O, Co(NO3)2·6H2O, Fe(NO3)3·9H2O, (NH4)6Mo7O 24 4H2O, (NH4)6H2W 12 O 40 · one of xH2O, the zeolite molecular sieve is one of SAPO-11, SAPO-5, SAPO-18, SAPO-34, ZSM-48, USY, beta; the silicon-aluminum molar ratio (SiO2 / Al2O3) of SAPO-11 is 0.2-0.8, the silicon-aluminum molar ratio of ZSM-48 is 50-100, the silicon-aluminum molar ratio of USY is 2-8, and the silicon-aluminum ratio of beta is 20-80;

[0035] Step 2: placing the loaded impregnated sample A in a muffle furnace, calcining at 400-600° C. for at least 2 h in an air atmosphere at a heating rate of 1-5° C. / min to obtain sample B;

[0036] Step 3: Place sample B in a tube furnace and reduce it in a hydrogen atmosphere with a minimum hydrogen volume space velocity of 400 h –1 , calcined at 500-800℃ for at least 3h, with a heating rate of 0.5-4℃ / min, and reduced to obtain sample C;

[0037] Step 4: Disperse sample C in water, ultrasonicate for at least 30 minutes, and heat the sample C dispersion to 50-100°C while stirring; then, add an aqueous solution containing an electronic regulator to the sample C dispersion, and the mass ratio of the electronic regulator to the transition metal salt is 0.25-1.26; after stirring for at least 30 minutes, filter the product and thoroughly wash and dry it with water to obtain the final catalyst, wherein the electronic regulator is one of La(NO3)3·6H2O, Ce(NO3)3·6H2O, and SnCl2·2H2O.

[0038] The anti-poisoning phosphide supported catalyst is prepared by the above method. By adjusting the synthesis conditions of the transition metal phosphide, including factors such as the heating rate, the reduction method, the ratio of the transition metal to the phosphorus source, and the loading amount, the influence of the molecular sieve on the generation of the impurity phase is minimized when the transition metal phosphide is generated, and the generation of impurity phases such as AlPO4 and NiAl2O4 is reduced, thereby ensuring the normal functioning of the catalytic activity of the phosphide. The loading amount of the transition metal phosphide will also affect the activity of the catalyst. Only a suitable loading amount can improve the catalytic activity of the catalyst. For example, when the loading amount of the transition metal phosphide is increased to 15wt%, the catalyst is inactive.

[0039] By grafting metal oxides (CeO2, SnO2, La2O3) on the surface of transition metal phosphides, the metal oxides generated on the surface have lower electronegativity than transition metal phosphides, so the charge part is transferred to the transition metal phosphides, and the original δ+ valence of the metal in the transition metal phosphides is converted into less positive charge, making it more difficult for phosphorus species in the crude oil to combine with the transition metal phosphides; using intermediate valence metal salts (Ce 3+ Sn 2+ The metal phosphide is electro-reduced in the dispersion, and the metal changes from ionic state to solid precipitation, so that the metal oxide grows only on the surface of the transition metal phosphide, rather than the entire surface of the catalyst. By adjusting the electron density of the active site, the reaction energy barrier is increased, thereby greatly extending the service life of the catalyst. The prepared anti-poisoning phosphide supported catalyst has a hydrogenation isomerization effect. On the one hand, the use of non-precious metals reduces the catalyst cost, and on the other hand, it can limit the cracking capacity and avoid excessive cracking of the raw material; and ensure that the catalyst has an anti-poisoning effect to improve the stability of the catalyst.

[0040] The catalyst can be used in the second step of the two-step method for preparing bio-jet fuel from vegetable oil. The product of vegetable oil hydrodeoxygenation is used as a raw material, and is hydroisomerized to finally obtain high-quality bio-jet fuel. The hydrodeoxygenation catalyst can generally be a bifunctional catalyst with a metal-supported carrier. The metal is mainly one or more of the precious metals Pt, Pd, Ru, Rh, etc., and the non-precious metal is mainly one or more of the transition metals such as Ni, Co, Mo, W, Fe, etc. The supported carrier is mainly a metal oxide such as alumina, titanium oxide, zirconium oxide, or a composite carrier in which two of them are combined together. Taking cottonseed oil as an example, the cottonseed oil is first hydrodeoxygenated by a hydrodeoxygenation catalyst to form an HDO product, and then hydroisomerized by an anti-poisoning phosphide-supported catalyst. The specific preparation method is as follows:

[0041] Step (1) loading the catalyst into the constant temperature range of a continuous flow high pressure fixed bed reactor, and loading a ceramic ring of at least 20 cm on the upper layer of the catalyst as a preheating layer;

[0042] Step (2) 40-100 wt % cottonseed oil hydrodeoxygenation (HDO) product-cyclohexane solution is pumped into the reactor by a pressure pump, wherein the liquid hourly space velocity of the mixed solution is 0.5-1.5 h –1 , reaction temperature is 290-400℃, hydrogen pressure is 1.5-4.0MPa, hydrogen-oil ratio is 400-1400;

[0043] Step (3) collecting the product by condensation and then performing qualitative and quantitative analysis on the product after the reaction using gas chromatography;

[0044] After the reaction in step (4) is completed, the feed is first stopped, and then hydrogen is continued to be purged for at least 1 hour, and then the temperature is lowered, and the hydrogen is turned off after the temperature drops below 100°C.

[0045] Through experiments, it was found that the freezing point of the prepared bio-jet fuel is generally lower than -50°C, which meets the national standard (<-40°C); the bio-jet fuel has a high yield, up to 71.58%, and a low proportion of non-condensable gas, that is, the degree of catalyst cracking is low, and most of it is kerosene product; the anti-poisoning phosphide loaded catalyst is relatively stable and can significantly extend its service life.

[0046] The scheme of the present invention is described below in conjunction with the accompanying drawings, wherein the experimental methods without specific operating steps are all carried out in accordance with the corresponding product instructions, and the instruments, reagents, and consumables used in the examples can all be purchased from commercial companies unless otherwise specified.

[0047] Example 1

[0048] (1) After 2.74 g of Ni(NO3)2·6H2O, 0.6229 g of (NH4)2HPO4 and water were mixed and stirred to dissolve at room temperature, the mixture was impregnated onto 13.3 g of SAPO-11 by an equal volume impregnation method, allowed to stand at room temperature for 1 hour, and then dried at 120°C for 3 hours to obtain sample A;

[0049] (2) placing sample A in a muffle furnace and calcining at 500°C for 2 h in an air atmosphere at a heating rate of 5°C / min to obtain sample B;

[0050] (3) Sample B was placed in a tube furnace and calcined at 650°C for 3 h in a hydrogen atmosphere at a hydrogen flow rate of 200 mL / min and a heating rate of 3°C / min to obtain sample C;

[0051] (4) 14 g of sample C was dispersed in 250 mL of water, ultrasonicated for 0.5 h, stirred continuously, and the suspension was heated to 80 °C. Subsequently, 1.758 g of Ce(NO3)3·6H2O was slowly added to the suspension. After stirring for 1 h, the product was filtered and thoroughly washed with water, and then dried at 80 °C for 8 h to obtain the final catalyst Cat-1.

[0052] Cat-1 was examined and the XPS spectrum of the Ni 2P orbital was detected; the results are as follows Figure 1 As shown, the XPS spectrum confirms the presence of phosphide in the catalyst. In the Ni2P orbital diagram of Cat-1, 853.5 eV is Ni δ+ This indicates that the transition metal phosphide was successfully synthesized (Ni2P in Cat-1). 0 The peak at 857.5 eV belongs to Ni 2+ . δ+ The binding energy is slightly higher than that of Ni 0 phase, but lower than Ni 2+ , indicating that Ni in Ni2P carries a partial positive charge. 2+ The peak is because the catalyst is exposed to air, Ni 0 Oxidation inevitably occurs.

[0053] Example 2

[0054] The preparation steps of Example 2 are the same as those of Example 1, except that 2.74 g Ni(NO3)2·6H2O in step (1) is replaced by 2.74 g Co(NO3)2·6H2O. The resulting catalyst is numbered Cat-2 and its composition is listed in Table 1.

[0055] Example 3

[0056] The preparation steps of Example 3 are the same as those of Example 1, except that 2.74 g Ni(NO3)2·6H2O in step (1) is replaced by 3.81 g Fe(NO3)3·9H2O. The resulting catalyst is numbered Cat-3 and its composition is listed in Table 1.

[0057] Example 4

[0058] The preparation steps of Example 4 are the same as those of Example 1, except that 2.74 g Ni(NO3)2·6H2O in step (1) is replaced by 1.66 g (NH4)6Mo7O 24 ·4H2O, the obtained catalyst is numbered Cat-4, and its composition is listed in Table 1.

[0059] Example 5

[0060] The preparation steps of Example 5 are the same as those of Example 1, except that 2.74 g Ni(NO3)2·6H2O in step (1) is replaced by 1.85 g ammonium metatungstate. The resulting catalyst is numbered Cat-5, and its composition is listed in Table 1.

[0061] Example 6

[0062] The preparation steps of Example 6 are the same as those of Example 1, except that 0.6229 g (NH4)2HPO4 in step (1) is replaced by 0.5438 g phosphoric acid. The resulting catalyst is numbered Cat-6, and its composition is listed in Table 1.

[0063] Example 7

[0064] The preparation steps of Example 7 are the same as those of Example 1, except that 0.6229 g (NH4)2HPO4 in step (1) is replaced by 0.5424 g NH4H2PO4. The resulting catalyst is numbered Cat-7, and its composition is listed in Table 1.

[0065] Example 8

[0066] The preparation steps of Example 8 are the same as those of Example 1, except that 2.74 g Ni(NO3)2·6H2O in step (1) is replaced by 3.81 g Fe(NO3)3·9H2O, and 0.6229 g (NH4)2HPO4 is replaced by 0.5424 g NH4H2PO4. The resulting catalyst is numbered Cat-8, and its composition is listed in Table 1.

[0067] Example 9

[0068] The preparation steps of Example 9 are the same as those of Example 1, except that 2.74 g Ni(NO3)2·6H2O in step (1) is replaced by Co(NO3)2·6H2O, and 0.6229 g (NH4)2HPO4 is replaced by 0.5438 g phosphoric acid. The resulting catalyst is numbered Cat-9, and its composition is listed in Table 1.

[0069] Example 10

[0070] The preparation steps of Example 10 are the same as those of Example 1, except that SAPO-11 in step (1) is replaced by ZSM-48. The resulting catalyst is numbered Cat-10, and its composition is listed in Table 1.

[0071] Embodiment 11

[0072] The preparation steps of Example 11 are the same as those of Example 1, except that SAPO-11 in step (1) is replaced by USY. The resulting catalyst is numbered Cat-11, and its composition is listed in Table 1.

[0073] Example 12

[0074] The preparation steps of Example 12 are the same as those of Example 1, except that SAPO-11 in step (1) is replaced with beta. The resulting catalyst is numbered Cat-12, and its composition is listed in Table 1.

[0075] Embodiment 13

[0076] The preparation steps of Example 13 are the same as those of Example 1, except that the muffle furnace calcination temperature in step (2) is changed to 400°C and the heating rate is changed to 3°C / min. The resulting catalyst is numbered Cat-13 and its composition is listed in Table 1.

[0077] Embodiment 14

[0078] The preparation steps of Example 14 are the same as those of Example 1, except that the hydrogen flow rate in step (3) is changed to 100 mL / min and the heating rate is changed to 3°C / min. The resulting catalyst is numbered Cat-14 and its composition is listed in Table 1.

[0079] Embodiment 15

[0080] The preparation steps of Example 15 are the same as those of Example 1, except that the hydrogen flow rate in step (1) is changed to 300 mL / min and the heating rate is changed to 3°C / min. The resulting catalyst is numbered Cat-15 and its composition is listed in Table 1.

[0081] Example 16

[0082] The preparation steps of Example 16 are the same as those of Example 1, except that the water bath temperature in step (4) is changed to 50°C. The resulting catalyst is numbered Cat-16 and its composition is listed in Table 1.

[0083] Embodiment 17

[0084] The preparation steps of Example 17 are the same as those of Example 1, except that the amount of Ni(NO3)2·6H2O added in step (1) is changed to 1.096 g, and the amount of Ce(NO3)3·H2O added in step (4) is changed to 0.7032 g. The resulting catalyst is numbered Cat-17, and its composition is listed in Table 1.

[0085] Embodiment 18

[0086] The preparation steps of Example 18 are the same as those of Example 1, except that the amount of Ni(NO3)2·6H2O added in step (1) is changed to 5.48 g, and the amount of Ce(NO3)3·6H2O added in step (4) is changed to 3.516 g. The resulting catalyst is numbered Cat-18, and its composition is listed in Table 1.

[0087] Embodiment 19

[0088] The preparation steps of Example 19 are the same as those of Example 1, except that 1.758 g Ce(NO3)3·6H2O in step (4) is replaced by 1.86 g La(NO3)3·6H2O. The resulting catalyst is numbered Cat-19 and its composition is listed in Table 1.

[0089] Embodiment 20

[0090] The preparation steps of Example 20 are the same as those of Example 1, except that 1.758 g Ce(NO3)3·6H2O in step (4) is replaced by 1.048 g SnCl2·2H2O. The resulting catalyst is numbered Cat-20, and its composition is listed in Table 1.

[0091] Comparative Example 1

[0092] The measure of removing the electron regulator is aimed at comparing with Example 1 to prove the effect of CeO2 as an electron regulator on the catalyst stability.

[0093] The preparation process is similar to that of Example 1, except that step (4) is eliminated. Sample C is the final catalyst, numbered Cat-21.

[0094] Comparative Example 2

[0095] The active metal was changed to metallic Ni in order to compare the difference between transition metal phosphides and the corresponding metal elements as active metals.

[0096] The preparation process is:

[0097] (1) After 3.4677 g of Ni(NO3)2·6H2O and water were mixed and stirred to dissolve at room temperature, the mixture was impregnated onto 13.3 g of SAPO-11 by an equal volume impregnation method, allowed to stand at room temperature for 1 h, and then dried at 120°C for 3 h to obtain sample A;

[0098] (2) placing sample A in a muffle furnace and calcining at 500°C for 2 h in an air atmosphere at a heating rate of 5°C / min to obtain sample B;

[0099] (3) Before loading the catalyst into the reactor for reaction, it was reduced at 400°C for 4 h under H2 atmosphere. This catalyst was numbered Cat-22.

[0100] Comparative Example 3

[0101] The active metal was changed to the noble metal Pt in order to compare the activity difference between the catalyst and the noble metal catalyst. The preparation process was similar to that of Comparative Example 2, except that 3.4677 g of Ni(NO3)2·6H2O in step 1 was replaced by 3.3525 g of chloroplatinic acid solution with a mass content of 0.011633 g / g. The obtained catalyst was numbered Cat-23.

[0102] Comparative Example 4

[0103] The preparation steps are the same as those in Example 1, except that the amount of Ni(NO3)2·6H2O added in step (1) is changed to 9.1978 g, and the amount of (NH4)2HPO4 added is changed to 2.0886 g. The resulting catalyst is numbered Cat-24.

[0104] Table 1

[0105]

[0106]

[0107] Example 21: Application of anti-poisoning phosphide supported catalyst in the preparation of bio-jet fuel from vegetable oil

[0108] The evaluation process and conditions of the catalyst are:

[0109] (1) 7.4305 g of Ni(NO3)2·6H2O was dissolved in a certain amount of water, and the Ni(NO3)2·6H2O solution was impregnated onto 13.5 g of γ-Al2O3 by an equal volume impregnation method. After standing for 1 hour, the mixture was dried and then calcined at 500°C for 3 hours in a muffle furnace under a flowing air atmosphere. Finally, the catalyst was reduced at 400°C for 4 hours under a hydrogen atmosphere to obtain 15% Ni / Al2O3, which is the catalyst for the hydrodeoxygenation process of cottonseed oil.

[0110] (2) 15% Ni / Al2O3 was placed in a fixed bed reactor and heated to 350°C under flowing hydrogen, where the volume space velocity of hydrogen was 200 h –1 , the hydrogen pressure was 3MPa; the reaction raw material was 60wt.% cottonseed oil-cyclohexane solution, and the volume space velocity was 1h -1 The hydrodeoxygenation product of the upper organic phase of the product is taken as the raw material for catalyst hydroisomerization. The composition of cottonseed oil and its hydrodeoxygenation product is shown in Table 2;

[0111] Table 2

[0112]

[0113]

[0114] (3) loading the poison-resistant phosphide-supported hydroisomerization catalyst into the constant temperature range of a continuous flow high-pressure fixed bed reactor, and loading a ceramic ring of at least 20 cm on the upper layer of the catalyst as a preheating layer;

[0115] (4) A 60 wt% cottonseed oil HDO product-cyclohexane solution was pumped into the reactor by a pressure pump, wherein the liquid hourly space velocity of the mixed solution was 1 h –1 , reaction temperature is 345℃, hydrogen pressure is 3MPa, hydrogen-to-oil ratio is 1000;

[0116] (5) collecting the product by condensation;

[0117] (6) After the reaction is completed, stop feeding first, then continue to purge with hydrogen for at least 1 hour, then cool down, and turn off the hydrogen after the temperature drops below 100°C.

[0118] The gas after the reaction was qualitatively and quantitatively analyzed by gas chromatography, and samples were taken every 1 hour. The product composition was analyzed by gas chromatography, and the sample was taken at the reaction point of 2 hours. The catalysts in Examples 1-20 and Comparative Examples 1-4 were evaluated by the above method, and the product composition and other data of different catalysts at 345°C are listed in Table 3. The products obtained by the reaction in the above embodiments and comparative examples were distilled by the method specified in GB / T9168, and the fractions of 150-280°C were collected. The freezing point of the fractions of 150-280°C was determined by the method specified in GB / T2430-2018, and the physical and chemical parameters of the bio-jet fuel distillation components of Cat-1 at 150-280°C are listed in Table 4.

[0119] Table 3

[0120]

[0121]

[0122] Table 4

[0123] <![CDATA[Density / (kg / m 3 )]]> 804.7 Acid value / (mgKOH / g) 0.012 Flash point / (℃) 70 Freezing point / (℃) -55 S content (μg / g) 4.1 N content (μg / g) <1

[0124] From the data results in Table 3, it can be seen that the anti-poisoning phosphide supported catalyst has a high yield of up to 71.58% for preparing bio-jet fuel from cottonseed oil HDO product, and the freezing point is generally lower than -50°C, meeting the national standard (<-40°C). At the same time, the proportion of non-condensable gas is low, that is, the degree of catalyst cracking is low, and most of the product is kerosene. Compared with Comparative Example 3 (Cat-23), the embodiment is comparable to the catalytic activity of the precious metal catalyst in terms of freezing point, yield and generation of non-condensable gas, which greatly reduces the cost of the catalyst.

[0125] By adjusting the heating rate, reduction method, ratio of transition metal to phosphorus source, loading amount and other factors of the synthesis of transition metal phosphide, the influence of the molecular sieve carrier on the generation of impurities in the synthesis of phosphide is minimized, the generation of impurities such as AlPO4 and NiAl2O4 is reduced, and the catalytic activity of the phosphide is ensured to function normally. As shown in the results of Comparative Example 4 (Cat-24), if the loading amount of the phosphide is increased to 15%, the catalyst is directly deactivated, which shows that the synthesis strategy in the present invention plays a protective role in the formation of the active center of the phosphide.

[0126] By grafting electron regulators on the surface of transition metal phosphides, the service life of transition metal phosphides can be greatly extended by preventing phosphorus and sulfur compounds in animal and plant oils from poisoning them. Figure 2 As shown in the figure, the activity of Cat-1 remained almost unchanged after continuous testing for 180 hours at a hydrogen-to-oil ratio of 1000, a space velocity of 1,3MPa H2, and 345°C. The continuous testing effect diagram of Comparative Example 1 (Cat-1) without the addition of an electronic regulator ( Figure 3 ) shows that after the cottonseed oil HDO product was introduced, the catalyst activity dropped rapidly, and the proportion of bio-jet fuel product dropped from 72.12% in 1 hour to 42.13% after 4 hours. The isomer ratio dropped from 4.12 in 1 hour to 2.18 in 4 hours. The freezing point of the jet fuel component also changed to -27°C, which no longer meets the standard requirements. Therefore, the strategy of the electronically regulated phosphide active center of the present invention can significantly extend the service life of the catalyst.

[0127] The embodiments of the present invention are described in detail above, but the contents described are only preferred embodiments of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A method for preparing a poison-resistant phosphide supported catalyst, characterized in that: The transition metal phosphide is loaded onto the molecular sieve, and after calcination and reduction, a metal oxide with an electron regulating function is generated on the surface of the transition metal phosphide to form a poison-resistant phosphide loaded catalyst.

2. The method for preparing a poison-resistant phosphide supported catalyst according to claim 1, characterized in that: The specific steps are as follows: Step 1: Mix and stir the transition metal salt, inorganic phosphorus source and water, impregnate them onto the molecular sieve by an equal volume impregnation method, and dry them to obtain sample A; Step 2: calcining sample A to obtain sample B; Step 3: reducing sample B with hydrogen to obtain sample C; Step 4: Disperse sample C in water, add it to 50-100°C, add an electronic regulator, stir the reaction, filter and dry the product to obtain a poison-resistant phosphide-supported catalyst.

3. The method for preparing a poison-resistant phosphide supported catalyst according to claim 1 or 2, characterized in that: The electron modifier is one of La(NO3)3·6H2O, Ce(NO3)3·6H2O, and SnCl2·2H2O; Transition metal salts are Ni(NO3)2·6H2O, Co(NO3)2·6H2O, Fe(NO3)3·9H2O, (NH4)6Mo7O 24 4H2O, (NH4)6H2W 12 O 40 One of xH2O; The inorganic phosphorus source is one or more of phosphoric acid, NH4H2PO4, and (NH4)2HPO4.

4. The method for preparing a poison-resistant phosphide supported catalyst according to claim 3, characterized in that: The molecular sieve is a zeolite molecular sieve, and the zeolite molecular sieve is one of SAPO-11, SAPO-5, SAPO-18, SAPO-34, ZSM-48, USY, and beta.

5. The method for preparing a poison-resistant phosphide supported catalyst according to claim 4, characterized in that: The silicon to aluminum molar ratio (SiO2 / Al2O3) of SAPO-11 is 0.2-0.8, the silicon to aluminum molar ratio of ZSM-48 is 50-100, the silicon to aluminum molar ratio of USY is 2-8, and the silicon to aluminum ratio of beta is 20-80.

6. The method for preparing a poison-resistant phosphide supported catalyst according to claim 4, characterized in that: The mass ratio of zeolite molecular sieve to transition metal salt is 2.3-15, the mass ratio of zeolite molecular sieve to inorganic phosphorus source is 10.1-66.3, the molar ratio of transition metal salt to inorganic phosphorus source is 0.5-3; the mass ratio of electronic regulator to transition metal salt is 0.25-1.

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7. The method for preparing a poison-resistant phosphide supported catalyst according to claim 1 or 2, characterized in that: In step 2, the calcination conditions are 400-600°C for at least 2h, and the heating rate is 1-5°C / min; In step 3, the reduction condition is that the minimum volume space velocity of hydrogen is 400h –1 , calcined at 500-800℃ for at least 3h, with a heating rate of 0.5-4℃ / min.

8. The poison-resistant phosphide supported catalyst prepared by the method for preparing the poison-resistant phosphide supported catalyst according to any one of claims 1 to 7.

9. Use of the anti-poisoning phosphide supported catalyst according to claim 8 in the preparation of bio-jet fuel from vegetable oil.

10. The use according to claim 9, characterized in that: The process of hydroisomerization of cottonseed oil hydrodeoxygenation product to prepare bio-jet fuel is as follows: Step 1: Load the catalyst into the constant temperature range of the continuous flow high pressure fixed bed reactor, and load a ceramic ring of at least 20 cm on the upper layer of the catalyst as a preheating layer; Step 2: 40-100 wt % cottonseed oil hydrodeoxygenation (HDO) product-cyclohexane solution is pumped into the reactor by a pressure pump, wherein the liquid hourly space velocity of the mixed solution is 0.5-1.5 h –1 , the reaction temperature is 290-400℃, the hydrogen pressure is 1.5-4.0MPa, and the hydrogen-oil ratio is 400-1400; the condensed and collected product is the aviation kerosene component; Step 3: After the reaction is completed, stop feeding first, then continue to purge with hydrogen for at least 1 hour, then cool down, and turn off the hydrogen after the temperature drops below 100°C.

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