A foamy molecular sieve and a catalyst for the hydroisomerization of normal alkanes prepared therefrom

Abstract

The present invention relates to a foamy molecular sieve and a normal alkane hydroisomerization catalyst prepared therefrom. The foamy molecular sieve of the present invention is at least one of the one-dimensional mesoporous molecular sieves after fluorination treatment; obtained by mixing the molecular sieve raw powder with a fluorine source, water and an oxidant. The normal alkane hydroisomerization catalyst prepared by the foamy molecular sieve of the present invention, the main active metal component compound, the auxiliary component compound, etc., can be applied to the hydroisomerization reaction of the model compound, with high reactivity and isomer selectivity, especially the selectivity of multi-branched isomerized hydrocarbons is significantly increased (≥60%); applied to the hydroisomerization reaction of F-T wax oil, with high base oil yield and low pour point, and the product has a high viscosity index. At the same time, the preparation process of the normal alkane hydroisomerization catalyst and the foamy molecular sieve of the present invention is simple, low cost, and has excellent prospects for promotion and application.

Description

Technical Field

[0001] The invention belongs to the technical field of catalysts, and in particular relates to a foamy molecular sieve and a normal alkane hydroisomerization catalyst prepared by using the same. Background Art

[0002] As the automobile industry develops towards high speed and energy saving, and environmental regulations become increasingly stringent, higher requirements are placed on lubricants. Lubricant base oil accounts for a high proportion of lubricants. The traditional method of improving lubricant performance by simply changing additives can no longer meet the requirements, so it is necessary to improve and select high-quality lubricant base oil.

[0003] Fischer-Tropsch wax oil is sulfur-free, nitrogen-free, and low in aromatics, and has excellent oxidation stability and a high viscosity index. Using Fischer-Tropsch wax as raw material, high-quality lubricant base oil can be obtained through hydroisomerization technology, with a viscosity index of more than 130 and a pour point as low as -40°C to -60°C. Its key properties are significantly better than mineral base oils.

[0004] A typical isomerization catalyst is a bifunctional catalyst, in which the metal component provides the hydrogenation / dehydrogenation function, and the acid carrier provides the isomerization acid function. Using one-dimensional mesoporous molecular sieve materials as the main component of the acid carrier, its excellent pore shape selectivity can be used to improve the activity, selectivity and stability of the isomerization catalyst. Therefore, molecular sieves such as ZSM-23, ZSM-22, ZSM-48, Nu-10, and Theta-1 show excellent application prospects in the isomerization reaction of Fischer-Tropsch wax oil to produce lubricating oil base oil.

[0005] CN105032478A discloses a catalyst for FT synthesis of middle distillate oil and a core-shell composite molecular sieve dedicated thereto. The catalyst has an adjustable ratio of an inner core ZSM-22 molecular sieve and an outer shell mesoporous MCM-41 molecular sieve, and exhibits a high isomerization selectivity in the hydroisomerization reaction of middle distillate oil, especially a significant improvement in the selectivity of multi-branched alkanes.

[0006] CN110856819A discloses a method for preparing a surface aluminum-rich ZSM-48 molecular sieve. The obtained molecular sieve has high crystallinity and effective acid centers are concentrated on the outer surface. It has high activity and isomerization selectivity in the hydroisomerization reaction of n-hexadecane.

[0007] CN107286978B discloses an isomerization catalyst comprising at least two components, a molecular sieve and a Group VIII noble metal, and designs different loading methods in a reactor according to the flow direction of the feedstock oil, thereby achieving an increase in the yield, pour point and viscosity index of the lubricating oil base oil.

[0008] CN105749964B discloses a method for preparing a hydroisomerization / cracking catalyst and a catalyst. First, a sodium-type ZSM 23 molecular sieve containing a template is treated with an alkaline solution of a certain concentration, and then the template is removed by washing, drying, and roasting, and then a hydrogen-type ZSM 23 molecular sieve is prepared. The catalyst provided by the invention is used in the conversion process of Fischer-Tropsch wax, and has better catalytic activity and target product selectivity.

[0009] In summary, the hydroisomerization of Fischer-Tropsch wax oil is an important direction for the development of lubricant base oil production technology. In order to further improve the yield and product quality of lubricant base oil, it will still be an important development direction to obtain isomerization reaction catalysts with higher performance using one-dimensional mesoporous molecular sieves as the main component of the acid carrier. Summary of the invention

[0010] The purpose of the present invention is to provide a foam molecular sieve and a catalyst for the hydroisomerization of normal alkanes prepared therefrom, so as to solve the problems of difficulty in improving the yield of the hydroisomerization reaction of normal alkanes, harsh reaction conditions, large diffusion restriction, and the products being mainly single-branched isomerized hydrocarbons.

[0011] The first aspect of the present invention provides a foamy molecular sieve, which is at least one of the one-dimensional mesoporous molecular sieves after fluorination treatment; obtained by mixing molecular sieve raw powder with a fluorine source, water and an acidic oxidant.

[0012] Preferably, the mass ratio of the molecular sieve raw powder, fluorine source, acidic oxidant and water is 0.005-0.2: 0.05-0.8: 0.1-0.3: 1. The mass ratio of the fluorine source to water is preferably 0.1-0.8: 1, specifically 0.2: 1, 0.4: 1 and 0.5: 1. The mass ratio of the oxidant to water is preferably 0-0.2: 1, more preferably 0-0.15: 1.

[0013] Preferably, the molecular sieve raw powder is at least one of ZSM-23, ZSM-22, ZSM-48, Nu-10, and Theta-1 one-dimensional mesoporous molecular sieves; the foamy molecular sieve is selected from at least one of fluorinated ZSM-23, ZSM-22, ZSM-48, Nu-10, and Theta-1 one-dimensional mesoporous molecular sieves. The molecular sieve raw powder can be sodium molecular sieve raw powder, potassium molecular sieve raw powder, ammonia molecular sieve raw powder, and hydrogen molecular sieve raw powder. The fluorine source is at least one of hydrogen fluoride, ammonium fluoride, ammonium bifluoride, tetrabutylammonium fluoride, tetrapropylammonium fluoride, tetraethylammonium fluoride, and tetramethylammonium fluoride; the oxidant is at least one of H2O2, HClO, HNO3, HClO4, HBrO, HOI, HBrO4, and HIO4.

[0014] The present invention also provides a method for preparing the above-mentioned foamed molecular sieve, comprising the following steps: mixing the molecular sieve raw powder with a fluorine source, water and an oxidant, reacting for 10 to 200 minutes at a stirring speed of 50 to 800 rpm and a temperature of 0 to 95° C.; then performing solid-liquid separation, washing with water, and drying at 60 to 150° C. for 3 to 24 hours. Preferably, the solid-liquid separation process is vacuum filtration or centrifugal separation.

[0015] Preferably, the silicon-to-aluminum ratio of the molecular sieve raw powder can be 30, 40, 50, 55, 60, 65, 75, 80, 90, 100, 120 and 200 and any value in the range formed by any two of the above point values. Preferably, the silicon-to-aluminum ratio of the molecular sieve raw powder is 40-200.

[0016] The second aspect of the present invention provides an acidic carrier, comprising the above-mentioned foamed molecular sieve and a binder; the binder content is 10-90wt.%, preferably 10-80wt.%, more preferably 20-80wt.% of the mass of the foamed molecular sieve.

[0017] Preferably, the binder can be selected from one or more of alumina, titanium oxide, silicon oxide and clay, preferably alumina and / or silicon oxide, more preferably alumina, and its precursor can be selected from one or more of boehmite, pseudo-boehmite, diaspore and diaspore.

[0018] The present invention also provides a method for preparing the acidic carrier, comprising: mixing, kneading and molding the foamed molecular sieve and the binder, drying at 60-120°C for 6-48h, and then calcining at 450-800°C for 4-18h.

[0019] The third aspect of the present invention provides a catalyst for the hydroisomerization of normal alkanes, comprising a main active metal, an auxiliary agent and the above-mentioned acidic carrier; the main active metal and the auxiliary agent are distributed on the surface of the acidic carrier. The acidic carrier is made of a foamed molecular sieve and a binder.

[0020] Preferably, the main active metal component is at least one of Pt, Pd and Ni; the auxiliary component is at least one of Ce, La, Pr, Mg, Ca, Mo, Cu, Ga and In, more preferably Ce, La, Pr, Mg and In. The atomic ratio of the auxiliary metal to the main active metal is (0.1-20):1, preferably (0.5-15):1.

[0021] Preferably, the content of the main active metal is 0.05-5.0wt.%, preferably 0.05-3.0wt.% of the mass of the foamed molecular sieve in the acidic carrier; the content of the auxiliary agent is 0.03-20wt.%, preferably 0.03-10wt.% of the mass of the foamed molecular sieve in the acidic carrier.

[0022] The present invention also provides a method for preparing the above-mentioned normal alkane hydroisomerization catalyst, comprising the following steps:

[0023] (1) preparing a foamed molecular sieve; preferably, mixing the molecular sieve raw powder with a fluorine source, water and an oxidant to obtain a reaction mixture, treating the reaction mixture, separating the solid from the liquid, washing with water, and drying to obtain a foamed molecular sieve;

[0024] (2) preparing an acidic carrier; preferably, mixing the foamed molecular sieve and a binder, and sequentially kneading, molding, drying, and calcining to obtain a carrier;

[0025] (3) The main active metal component compound and the auxiliary component compound are loaded on the acidic carrier by impregnation method. After each impregnation, it needs to be dried and calcined. The drying temperature is 60-150°C and the time is 4-48h. The calcination temperature is 200-650°C and the time is 4-24h.

[0026] The impregnation method includes first impregnating the main active metal compound and then impregnating the auxiliary component compound, or first impregnating the auxiliary component compound and then impregnating the main active metal compound, or impregnating both at the same time. The main active metal compound and the auxiliary component compound can be loaded on the acidic carrier by one impregnation or multiple impregnations.

[0027] The main active metal compound can be any water-soluble compound containing a main active metal component, for example, it can be selected from but not limited to at least one of nitrates, sulfates and chlorides, preferably, it can be selected from at least one of tetraammineplatinum nitrate, chloroplatinic acid, ammonium chloroplatinate, ammonium chloroplatinite, tetraammoniumplatinum dichloride, platinum chloride, platinum nitrate and palladium chloride, palladium nitrate, palladium acetate, ammonium tetrachloropalladate and nickel nitrate, nickel dichloride; the auxiliary component compound can be any water-soluble compound containing an auxiliary component, for example, it can be selected from but not limited to at least one of nitrates, sulfates and chlorides of the auxiliary component.

[0028] The preparation method of the n-alkane hydroisomerization catalyst of the present invention is simple, and the auxiliary component and the main active component can be introduced step by step or in one step by an impregnation method. In addition, the introduction of the auxiliary component reduces the amount of the main active metal component while ensuring the catalytic effect (such as ensuring various indicators of the base oil of the obtained product).

[0029] According to a fourth aspect of the present invention, there is also provided the use of the above-mentioned normal alkane hydroisomerization catalyst for the hydroisomerization reaction of model compounds or Fischer-Tropsch wax oil.

[0030] The model compound is selected from at least one of n-heptane, n-decane, n-dodecane, n-tetradecane and n-hexadecane, preferably at least one of n-decane, n-dodecane, n-tetradecane and n-hexadecane.

[0031] The conditions of the hydroisomerization reaction include: reaction temperature of 200°C-430°C; hydrogen partial pressure of 0.5MPa-10MPa; volume space velocity of 0.2h -1 ~4h -1 ; The volume ratio of hydrogen to oil is (100-2000):1; Preferably, the conditions for the hydroisomerization include: temperature of 200℃-400℃; hydrogen partial pressure of 1MPa-10MPa; volume space velocity of 0.2h-1~4h-1; the volume ratio of hydrogen to oil is (100-2000):1.

[0032] The Fischer-Tropsch wax oil raw material is selected from Fischer-Tropsch wax, Fischer-Tropsch wax hydrocracking tail oil or Fischer-Tropsch wax hydrorefining tail oil.

[0033] The hydroisomerization reaction of the present invention further comprises a hydrogen reduction step before the catalyst is used, and the reduction conditions include: a temperature of 90-600° C., preferably 150-450° C.; and a time of 1-48 hours, preferably 4-24 hours.

[0034] Compared with the prior art, the present invention adopts fluorination post-treatment technology, combined with an acidic oxidant, to form a synergistic effect, optimizes the molecular sieve into a foam structure, realizes the innovative regulation of the molecular sieve structure, pores, and acidity, and obtains a foam molecular sieve with high crystallinity, exposes a large number of acid centers, has a mesoporous structure, improves diffusion restriction, and solves the core problem of narrow pores and large diffusion restriction of one-dimensional mesoporous molecular sieves. The normal alkane hydroisomerization catalyst prepared by the foam molecular sieve of the present invention has high reaction activity and isomer selectivity in the hydroisomerization reaction of the model compound, especially the selectivity of multi-branched isomerized hydrocarbons is significantly increased (≥60%), and when the conversion rate of n-hexadecane is 95.3%, the total isomer selectivity is maintained above 93%, of which the multi-branched isomer selectivity reaches 63.5%. The catalyst of the present invention can significantly improve the yield of isomerized products when the Fischer-Tropsch wax oil raw material is subjected to hydroisomerization to obtain lubricating oil base oil, and the pour point is lower. After the Fischer-Tropsch refined wax with a pour point of >40°C isomerized, the yield of the base oil fraction (>330°C) in the product is >80%, the pour point is -42°C, and the viscosity index (100°C) is 140.5 centistokes. At the same time, the preparation process of the catalyst and the foamed molecular sieve of the present invention is simple and the cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The left side is the ZSM-22 molecular sieve raw powder, and the right side is the transmission electron microscope photo of the molecular sieve after fluorination treatment in Example 1;

[0036] Figure 2 is a transmission electron microscope photograph of the molecular sieve after fluorination treatment in Example 2;

[0037] Figure 3 is a pore size distribution diagram of the molecular sieve after fluorination treatment in Example 1;

[0038] Figure 4 is a pore size distribution diagram of the molecular sieve after fluorination treatment in Example 2;

[0039] Figure 5 It is the XRD diagram of ZSM-22 molecular sieve raw powder and molecular sieve after fluorination treatment. DETAILED DESCRIPTION

[0040] To make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings, but the present invention is not limited thereto.

[0041] In the following examples, the product distribution in the model compound product was detected and analyzed by Agilent 7890A gas chromatograph. The viscosity index value of the isomerization product of the Fischer-Tropsch wax oil feedstock was measured by ASTM D2270 method; the pour point was measured by GB / T3535-2006 method.

[0042] Unless otherwise specified, the experimental methods used in the following examples are all conventional methods; the reagents, materials, etc. used in the following examples, unless otherwise specified, can be obtained from commercial channels.

[0043] Example 1

[0044] 50 g of ZSM-22 molecular sieve (silicon-aluminum ratio of 90) was added to 500 g of hydrofluoric acid aqueous solution, wherein the amount of hydrofluoric acid added was 2.5 g, and after mixing, the mixture was treated at a speed of 50 rpm and a temperature of 20°C for 20 min, and then vacuum filtered to separate the solid and liquid, and dried at 60°C for 24 h to obtain a foamed ZSM-22 molecular sieve. The morphology was observed by transmission electron microscopy as shown in the attached figure. Figure 1 As shown in Figure 2, the ZSM-22 molecular sieve changes from a rod-like morphology to a porous foam-like morphology. Figure 5 As shown, after treatment, the diffraction peak is sharp, proving that the crystallinity is improved. The obtained foam molecular sieve has high crystallinity, and the relative crystallinity can be increased to 150%.

[0045] 1) Pore size distribution such as Figure 3 As shown, a concentrated distribution occurs at pore sizes of 40-60 nm, which can be attributed to mesopores and macropores, indicating that the foamed molecular sieve obtained by treatment contains mesopores and macropores.

[0046] 2) The obtained molecular sieve was mixed with 5g pseudo-boehmite, 2.5g nitric acid and 2.5g sesbania powder, kneaded and formed, and then dried at 120°C for 24h and calcined at 500°C for 8h to obtain an acidic carrier. In this embodiment, sesbania powder has a bonding effect and is also an extrusion aid, and nitric acid is a peptizing agent to adjust the bonding property and strength.

[0047] 3) Weigh 0.57 g of chloroplatinic acid, dissolve it in deionized water to form a solution, drip the solution onto the acidic carrier, then dry it in an oven at 120° C. for 16 h, and finally calcine it at 500° C. for 6 h to obtain a catalyst precursor.

[0048] 4) Weigh 0.50 g of cerium nitrate, dissolve it in deionized water to form a solution, drip the solution into the catalyst precursor in step (2), then dry it in an oven at 120° C. for 12 h, and finally calcine it at 500° C. for 6 h. Finally, catalyst A1 is obtained, and the composition of the catalyst is shown in Table 1.

[0049] Example 2

[0050] 1) Add 50 g of ZSM-22 molecular sieve (silicon-aluminum ratio of 45) to 500 g of ammonium bifluoride and H2O2 aqueous solution, wherein the amount of ammonium bifluoride added is 5.0 g and the amount of H2O2 added is 25 g, and after mixing, the mixture is treated at a speed of 500 rpm and a temperature of 60°C for 60 min, and then the solid-liquid separation is performed by vacuum filtration, and the foamed ZSM-22 molecular sieve is obtained by drying at 100°C for 24 h. The morphology thereof is observed by transmission electron microscopy, as shown in FIG. Figure 2 The pore size distribution is shown in Figure 4 As shown, and Figure 3 In comparison, the distribution range of mesopores in this figure shifts toward macropores, indicating that the material obtained under this condition has a larger pore size and a wider distribution.

[0051] 2) The obtained molecular sieve was mixed with 20 g of pseudo-boehmite, 5.0 g of nitric acid and 2.5 g of sesbania powder and kneaded into a mixture, and then dried at 120° C. for 8 h and calcined at 550° C. for 4 h to obtain an acidic carrier.

[0052] 3) Weigh 0.48 g of chloroplatinic acid and dissolve it in deionized water to form a solution, drip the solution onto the acidic carrier, then dry it in an oven at 100° C. for 16 h, and finally calcine it at 550° C. for 8 h to obtain a catalyst precursor.

[0053] 4) Weigh 2.24 g of magnesium nitrate, dissolve it in deionized water to form a solution, drip the solution into the catalyst precursor in step (2), then dry it in an oven at 100° C. for 12 h, and finally calcine it at 550° C. for 6 h. Finally, catalyst A2 is obtained, and the composition of the catalyst is shown in Table 1.

[0054] Example 3

[0055] The catalyst was prepared by referring to the method described in Example 2, except that the molecular sieve used was ZSM-48 molecular sieve, and finally catalyst A3 was obtained. The composition of the catalyst is shown in Table 1.

[0056] Example 4

[0057] The catalyst was prepared by referring to the method described in Example 1, except that the molecular sieve used was ZSM-23 molecular sieve, and finally catalyst A4 was obtained. The composition of the catalyst is shown in Table 1.

[0058] Example 5

[0059] The catalyst was prepared by referring to the method described in Example 2, except that 1.12 g of indium nitrate trihydrate was used to replace the magnesium nitrate in Example 2 to load the catalyst precursor, and finally catalyst A5 was obtained.

[0060] Example 6

[0061] 1) 50 g of ZSM-48 molecular sieve (silicon-aluminum ratio of 120) was added to 500 g of tetraethylammonium fluoride and HClO aqueous solution, wherein the amount of tetraethylammonium fluoride added was 8.0 g and the amount of HClO added was 20 g, and after mixing, the mixture was treated at a speed of 400 rpm and a temperature of 80° C. for 10 min, and then the solid-liquid separation was performed by vacuum filtration, and the foamed ZSM-48 molecular sieve was obtained by drying at 80° C. for 24 h.

[0062] 2) The obtained molecular sieve was mixed with 20 g of pseudo-boehmite, 10.0 g of nitric acid and 5.0 g of sesbania powder, kneaded and formed, and then dried at 100° C. for 8 h and calcined at 550° C. for 4 h to obtain an acidic carrier.

[0063] 3) Weigh 1.43 g of palladium nitrate, dissolve it in deionized water to form a solution, drip the solution onto the support, then dry it in an oven at 100° C. for 8 h, and finally calcine it at 350° C. for 12 h to obtain a catalyst precursor.

[0064] 4) Weigh 1.64 g of cerium nitrate, dissolve it in deionized water to form a solution, drip the solution into the catalyst precursor in step (2), then dry it in an oven at 100° C. for 12 h, and finally calcine it at 520° C. for 6 h. Finally, catalyst A6 is obtained, and the composition of the catalyst is shown in Table 1.

[0065] Example 7

[0066] The catalyst was prepared by referring to the method described in Example 6, except that the molecular sieve used was ZSM-23 molecular sieve, and finally catalyst A7 was obtained. The composition of the catalyst is shown in Table 1.

[0067] Example 8

[0068] The catalyst was prepared by referring to the method described in Example 6, except that the amount of pseudo-boehmite added was 45 grams. Catalyst A8 was finally obtained. The composition of the catalyst is shown in Table 1.

[0069] Comparative Example 1

[0070] The catalyst was prepared by referring to the method described in Example 2, except that the molecular sieve used was a three-dimensional macroporous Beta molecular sieve. Catalyst D1 was finally obtained. The composition of the catalyst is shown in Table 1.

[0071] Comparative Example 2

[0072] 1) Add 50 g of ZSM-48 molecular sieve (silicon-aluminum ratio of 120) to 500 g of HClO aqueous solution, wherein the amount of HClO added is 20 g, and after mixing, treat at a speed of 400 rpm and a temperature of 80° C. for 10 min, then separate the solid and liquid by vacuum filtration, and dry at 80° C. for 24 h to obtain the molecular sieve.

[0073] 2) The obtained molecular sieve was mixed with 20 g of pseudo-boehmite, 10.0 g of nitric acid and 5.0 g of sesbania powder, kneaded and formed, and then dried at 100° C. for 8 h and calcined at 550° C. for 4 h to obtain an acidic carrier.

[0074] 3) Weigh 1.43 g of palladium nitrate, dissolve it in deionized water to form a solution, drip the solution onto the support, then dry it in an oven at 100° C. for 8 h, and finally calcine it at 350° C. for 12 h to obtain a catalyst precursor.

[0075] 4) Weigh 1.64 g of cerium nitrate, dissolve it in deionized water to form a solution, drip the solution into the catalyst precursor in step (2), then dry it in an oven at 100° C. for 12 h, and finally calcine it at 520° C. for 6 h. Finally, catalyst D2 is obtained, and the composition of the catalyst is shown in Table 1.

[0076] Comparative Example 3

[0077] The catalyst was prepared by referring to the method described in Example 2, except that the reaction temperature was 150° C., and finally catalyst D3 was obtained. The composition of the catalyst is shown in Table 1.

[0078] Comparative Example 4

[0079] The catalyst was prepared by referring to the method described in Example 6, except that the amount of HClO added was 40 g. Catalyst D4 was finally obtained. The composition of the catalyst is shown in Table 1.

[0080] Comparative Example 5

[0081] The fluorinated molecular sieve was prepared by referring to the method described in step 1) of Example 2, except that 225 g of ammonium bifluoride was added, and the structure of the molecular sieve was completely destroyed and amorphous.

[0082] Comparative Example 6

[0083] The fluorinated molecular sieve was prepared by referring to the method described in step 1) of Example 2, except that the amount of oxidant H2O2 added was increased to 75 g, and the structure of the molecular sieve was completely destroyed, becoming amorphous.

[0084] Example 9

[0085] Catalysts A1-A8 described in Examples 1-8 and catalysts D1-D2 described in Comparative Examples 1-2 were used, with n-hexadecane as the raw material, under the following process conditions: reaction temperature of 280-320°C, hydrogen partial pressure of 2.0 MPa, volume space velocity of 1.5 h -1 The hydroisomerization reaction was carried out at a hydrogen-to-oil volume ratio of 800, and the distribution of the products in the obtained products is shown in Tables 2 and 3.

[0086] According to the above examples and comparisons, it can be seen that compared with the untreated one-dimensional mesoporous molecular sieve catalyst, the fluorination treatment of the one-dimensional mesoporous molecular sieve can significantly improve the catalytic performance of the catalyst in the hydroisomerization reaction of the model compound and the Fischer-Tropsch wax. At the same time, the same technical means for treating the three-dimensional macroporous molecular sieve cannot obtain better catalytic performance.

[0087] Table 1 Catalyst ratios in Examples and Comparative Examples

[0088]

[0089] Table 2 Isomerization performance of catalysts in Examples and Comparative Examples for model compounds

[0090]

[0091]

[0092] Table 3 Isomerization reaction performance of catalysts of examples and comparative examples for Fischer-Tropsch synthesis wax oil

[0093]

Claims

1. A foamy molecular sieve, characterized in that: The foamy molecular sieve is at least one of the one-dimensional mesoporous molecular sieves after fluorination treatment; it is obtained by mixing molecular sieve raw powder with a fluorine source, water and an acidic oxidant; the mass ratio of the molecular sieve raw powder, the fluorine source, the acidic oxidant and water is 0.005-0.2:0.05-0.8:0.1-0.3:1; the molecular sieve raw powder is at least one of the one-dimensional mesoporous molecular sieves ZSM-23, ZSM-22, ZSM-48, Nu-10 and Theta-1; the fluorine source is at least one of hydrogen fluoride, ammonium fluoride, ammonium bifluoride, tetrabutylammonium fluoride, tetrapropylammonium fluoride, tetraethylammonium fluoride and tetramethylammonium fluoride; the acidic oxidant is at least one of H2O2, HClO, HNO3, HClO4, HBrO, HOI, HBrO4 and HIO4.

2. The method for preparing the foamed molecular sieve according to claim 1, characterized in that: The following steps are involved: The molecular sieve raw powder is mixed with a fluorine source, water and an oxidant, and the mixture is reacted for 10 to 200 minutes at a stirring speed of 50 to 800 rpm and a temperature of 0 to 95° C.; the mixture is then solid-liquid separated, fully washed with water, and dried at 60 to 150° C. for 3 to 24 hours.

3. An acidic carrier, characterized in that It comprises a binder and the foamed molecular sieve according to claim 1; the content of the binder is 10-90wt.% of the mass of the foamed molecular sieve; and / or the binder comprises one or more of aluminum oxide, titanium oxide, silicon oxide and clay.

4. The method for preparing the acidic carrier according to claim 3, characterized in that: include: The foamed molecular sieve and the binder are mixed, kneaded and formed, dried at 60-120° C. for 6-48 hours, and then calcined at 450-800° C. for 4-18 hours.

5. A catalyst for the hydroisomerization of normal alkanes, characterized in that: It comprises a main active metal, an auxiliary agent and the acidic carrier as claimed in claim 3; the main active metal is at least one of Pt, Pd and Ni; the auxiliary agent is at least one of Ce, La, Pr, Mg, Ca, Mo, Cu, Ga and In; the main active metal and the auxiliary agent are distributed on the surface of the acidic carrier.

6. The normal alkane hydroisomerization catalyst according to claim 5, characterized in that: The content of the main active metal is 0.05-5.0 wt.% of the mass of the foamed molecular sieve in the acidic carrier; the content of the auxiliary agent is 0.03-20 wt.% of the mass of the foamed molecular sieve in the acidic carrier.

7. The method for preparing a catalyst for the hydroisomerization of normal alkanes according to claim 5, characterized in that: The following steps are involved: (1) preparing a foamy molecular sieve; (2) preparing an acidic carrier; (3) The main active metal component compound and the auxiliary component compound are loaded on the acidic carrier by an impregnation method, and dried at 60-150° C. for 4-48 hours, and then calcined at 200-650° C. for 4-24 hours.

8. The use of the catalyst for the hydroisomerization of normal alkanes according to claim 5, characterized in that: Used for the hydroisomerization reaction of model compounds or Fischer-Tropsch wax oil.

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