Dehydrogenation catalyst for preparing ketone from hydroxyl and preparation method thereof

Abstract

The present application provides a kind of hydroxyl dehydrogenation preparation aldehyde or ketone dehydrogenation catalyst and its preparation method.The present application reduces the acidity of catalyst by introducing Li adjuvant, reduces the generation of by-product heavy oil.By reacting Li with silicon source to generate lithium silicate, Li is fixed, and by adding condensed aluminum phosphate to fix lithium silicate, the loss of lithium silicate is inhibited.By using water vapor hydrothermal treatment of catalyst at different temperatures, the pore of catalyst can be effectively enlarged, the mass transfer effect in the reaction process is improved, and the catalyst can have better dehydrogenation activity at low temperature.The catalyst prepared by the method described in the present application can achieve high activity at a lower temperature, the production of by-products is inhibited by adding alkaline adjuvant, and the alkaline adjuvant is effectively immobilized by adding solidifying agent, to improve the operating stability of the catalyst.

Description

Technical Field

[0001] This invention belongs to the field of catalyst preparation, specifically relating to a dehydrogenation catalyst for the preparation of aldehydes or ketones by hydroxyl dehydrogenation and its preparation method. Background Technology

[0002] This invention relates to a method for using C6-C 12 Catalysts for the dehydrogenation of alcohols to prepare the corresponding aldehydes or ketones. Cyclohexanone is an organic compound with the chemical formula (CH2)5CO, a saturated cyclic ketone in which the carbonyl carbon atom is contained within a six-membered ring. It is a colorless, transparent liquid with an earthy odor; when containing trace amounts of phenol, it has a minty smell. Industrially, it is mainly used as a raw material and solvent in organic synthesis; for example, it can dissolve nitrocellulose, coatings, and paints. Major downstream products include caprolactam and adipic acid. Cyclododecanoate is an important chemical raw material intermediate. Its preparation involves trimerizing butadiene to obtain cyclododecanetriene, followed by hydrogenation and oxidation to obtain a mixture of cyclododecyl alcohol and cyclododecanoate (KA oil). The cyclododecyl alcohol is then dehydrogenated to obtain pure cyclododecanoate. Cyclododecanoate is an important raw material in the fragrance industry; for example, muscone and muscpyridine are produced from cyclododecanoate. It is also an important intermediate in the field of engineering plastics; long-chain nylon resins such as PA12 and PA1212 can be obtained from cyclododecanetriene via a cyclododecanoate process.

[0003] Currently used dehydrogenation catalysts are mainly copper-based, including copper-magnesium, copper-aluminum, copper-zinc, and copper-chromium types. The advantages of copper-based dehydrogenation catalysts include a high space velocity, resulting in a smaller reactor volume for processing the same amount of reactants. Additionally, the reaction temperature is relatively low, effectively reducing equipment investment and operating energy consumption. Furthermore, their high selectivity reduces the amount of heavy oil components during the reaction, thus significantly increasing the catalyst's lifespan. Improving the dehydrogenation conversion rate while maintaining high selectivity is the current research focus.

[0004] Kuno et al. (Bull. Chem. Soc. Jpn., 1993, (66): 1699) used trimethylchlorosilane-modified hydrated zirconium oxide as a homogeneous dehydrogenation catalyst with a conversion rate of 98% and a selectivity of 100%. The catalyst reported in this patent has high activity, but the homogeneous catalyst and reaction products are difficult to separate, and the catalyst life is short. It is only in the theoretical research stage and does not yet have industrial application value. Chinese patent CN1056067A provides an industrial catalyst with the components CuO, ZnO, MgO, CaO and trace Na2O. When the reaction temperature is 250℃, the guaranteed conversion rate is above 65% and the selectivity is 99.5-100%; when the reaction temperature is 275-310℃, the guaranteed conversion rate is above 75% and the selectivity is above 99%. Although this catalyst has good activity, in order to further improve the dehydrogenation conversion rate, a higher reaction temperature must be used, and the catalyst activity is not significantly improved.

[0005] Currently, dehydrogenation catalysts exhibit low activity. Increasing the reaction temperature to improve activity leads to an increase in heavy oil production, thus affecting catalyst lifespan. Addressing the challenges of existing production processes, there is an urgent need to develop a highly active catalyst that can enhance dehydrogenation activity at lower temperatures, reduce the formation of heavy oil as a byproduct, and extend catalyst lifespan. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a dehydrogenation catalyst for the preparation of ketones from hydroxyl dehydrogenation. To overcome the problems of insufficient activity and the easy generation of heavy oil as a byproduct in existing dehydrogenation catalysts, a catalyst with high activity at a lower reaction temperature has been developed.

[0007] To achieve the above-mentioned objectives, the technical solution adopted by the present invention is as follows:

[0008] A dehydrogenation catalyst for the preparation of aldehydes or ketones by hydroxyl dehydrogenation, the catalyst comprising the following components:

[0009] Copper oxide 30-45 wt%, preferably 30-40 wt%, more preferably 35-40 wt%;

[0010] Zinc oxide 45-60 wt%, preferably 45-55 wt%, more preferably 50-55 wt%;

[0011] 8-20 wt% silica, preferably 12-20 wt%;

[0012] Lithium silicate 1-5 wt%, preferably 1-3 wt%;

[0013] Based on the weight of the catalyst.

[0014] The catalyst described in this invention reduces its acidity and the formation of heavy oil byproduct by introducing a Li promoter. Li is fixed by reacting Li with a silicon source to form lithium silicate, and then further fixed by adding condensed aluminum phosphate, thus inhibiting lithium silicate loss. Furthermore, by using hydrothermal treatment with steam at different temperatures, the catalyst pores are effectively enlarged, improving mass transfer during the reaction and enabling the catalyst to exhibit better dehydrogenation activity at low temperatures.

[0015] Another object of the present invention is to provide a method for preparing a dehydrogenation catalyst for the preparation of hydroxyl dehydrogenation to aldehydes or ketones.

[0016] A method for preparing the above-mentioned catalyst, the method comprising the following steps:

[0017] S1: Dissolve copper and zinc salts in water to prepare a salt solution, prepare an alkaline precipitant into an aqueous solution, and add a lithium-containing compound;

[0018] S2: Add water to the reactor, and then add the salt solution, silicon source, and alkaline precipitant to the reactor to precipitate the solution.

[0019] S3: After aging, add an additive aqueous solution and continue aging;

[0020] S4: The slurry from S3 is filtered and washed to obtain a filter cake, which is then dried and calcined to obtain a catalyst;

[0021] S5: After adding a binder to the catalyst and extruding it, it is filled into the reactor, treated with steam, and then calcined to obtain the target catalyst.

[0022] In this invention, the copper salt in S1 is selected from one or more of copper nitrate, copper chloride, and copper acetate.

[0023] In this invention, the zinc salt in S1 is selected from one or more of zinc nitrate, zinc chloride, and zinc acetate.

[0024] In this invention, the silicon source in S1 is silica sol and / or sodium silicate, preferably silica sol.

[0025] In this invention, the lithium-containing compound in S1 is lithium hydroxide and / or lithium nitrate, preferably lithium hydroxide.

[0026] In this invention, the concentration of the salt solution in S1 is 0.5-1M.

[0027] In this invention, the alkaline precipitant in S1 is one or more of sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, sodium hydroxide, potassium hydroxide, ammonium carbonate, ammonium bicarbonate, and ammonia water.

[0028] In this invention, the precipitation temperature in S2 is 55-75℃, preferably 62-72℃; the pH value is 6.5-8.0, preferably 6.8-7.5.

[0029] In this invention, the aging time in S3 is 2-4 hours, and the aging temperature is 65-80℃, preferably 68-78℃.

[0030] In this invention, the additive in S3 is condensed aluminum phosphate and / or aluminum tripolyphosphate; preferably, the amount of additive added is 1-3% of the total weight of the catalyst. Preferably, the aqueous solution of the additive is added after aging for 1 hour.

[0031] In this invention, the calcination temperature of the filter cake in S4 is 260-330℃, preferably 280-320℃, and the calcination time is 3-12h, preferably 4-8h.

[0032] In this invention, the processing method described in S5 is as follows: after the catalyst is loaded into the reactor, it is purged with air at 110-130°C for 1-2 hours to dry the catalyst. Then, it is treated with steam at the same temperature for 1-2 hours, then heated to 140-170°C for 1-2 hours, then further heated to 200-230°C for 1-2 hours, and finally cooled to 100-120°C for air drying for 1-3 hours.

[0033] In this invention, the roasting described in S5 is roasting at 280-350℃ for 2-4 hours.

[0034] In the method of this invention, the hydrogenation reaction is carried out in a fixed-bed hydrogenation reactor. Preferably, the catalyst is further subjected to a reduction treatment before use. In some examples, the method is as follows: the hydrogenation catalyst is packed into the fixed-bed hydrogenation reactor, and first, the temperature is raised to 400-450°C and a mixture of hydrogen and nitrogen containing 5-10 vol% H2 is introduced for pre-reduction for 1-3 hours. Then, the proportion of hydrogen in the hydrogen and nitrogen mixture is gradually increased to 100 vol%. During this process, the hot spot temperature of the catalyst bed must be controlled not to exceed 430°C. Then, reduction is carried out in a pure hydrogen atmosphere for 2-4 hours, with a gas hourly space velocity of 300-2000 h⁻¹ during the reduction process. -1 .

[0035] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0036] 1) By introducing the alkali metal Li as an additive, the acidity of the catalyst is reduced, thereby reducing the formation of the byproduct heavy oil.

[0037] 2) In order to overcome the problem that Li additives are easily lost in the presence of water, Li is fixed by reacting Li with silicon source to generate lithium silicate, and condensed aluminum phosphate is added during the aging process after the slurry is settled to fix the lithium silicate and inhibit the loss of lithium silicate.

[0038] 3) By using water vapor to hydrothermally treat the catalyst at different temperatures, the pore distribution of the catalyst can be effectively expanded, the macropore size of the catalyst can be increased, the mass transfer effect during the reaction can be improved, and the catalyst can have better dehydrogenation activity at low temperatures. Attached Figure Description

[0039] Figure 1 The results show a comparison of the stability data of the catalysts used in Example 3 and Comparative Example 3. Detailed Implementation

[0040] The following embodiments will further illustrate the method provided by the present invention, but the present invention is not limited to the listed embodiments and should also include any other known modifications within the scope of the claims of the present invention.

[0041] Copper nitrate trihydrate, Comio reagent, AR;

[0042] Zinc nitrate hexahydrate, Comio reagent, AR;

[0043] Silica sol, Linyi Kehan ​​Silicon Products Co., Ltd., 40% alkaline silica sol;

[0044] Sodium carbonate, Shandong Haihua Co., Ltd., food grade;

[0045] Condensed aluminum phosphate, Shijiazhuang Xinsheng Chemical Co., Ltd.

[0046] Cyclododecyl alcohol, Wanhua Chemical.

[0047] Chromatographic analysis conditions: Analysis was performed using a DB-5MS column (30m × 0.25mm × 0.25μm). Specific operating conditions were as follows: hold at 50℃ for 2 minutes, increase to 100℃ at 5℃ / min, hold for 5 minutes, increase to 260℃ at 15℃ / min, hold for 5 minutes. The injector temperature was 240℃, and the detector temperature was 260℃.

[0048] Example 1

[0049] Dissolve 90.6g of copper nitrate trihydrate and 220g of zinc nitrate hexahydrate in 1100ml of water to prepare a 1M salt solution. Dissolve 130g of sodium carbonate in water to prepare a 650g 20wt% sodium carbonate aqueous solution. Add 1.87g of LiOH·H2O and mix the solutions thoroughly.

[0050] Add 100g of water to the reactor, and add the above-prepared salt solution, alkaline precipitant and 23.35g of silica sol to the reactor in parallel. Control the precipitation time to 2h, the precipitation temperature to 55℃, and the precipitation pH to 8.0.

[0051] The slurry was aged for 4 hours at a controlled aging temperature of 65°C. After aging for 1 hour, 20g of condensed aluminum phosphate aqueous solution was added. The mass content of condensed aluminum phosphate was 5%. The aging continued until the predetermined time was reached.

[0052] The aged slurry was filtered and washed to obtain a filter cake; the filter cake was dried at 80°C for 4 hours and calcined at 280°C for 4 hours to obtain a catalyst.

[0053] The obtained catalyst was added to a binder and extruded into a 3mm diameter clover catalyst to obtain a 3*2-8mm clover catalyst. The catalyst was loaded into a reactor, heated to 120℃, and purged with air for 1 hour to dry the catalyst. Then, it was treated with steam at the same temperature for 1 hour, heated to 150℃ for 1 hour, further heated to 200℃ and treated with steam for 1 hour, cooled to 120℃ and air-dried for 3 hours, and then discharged from the reactor and calcined at 280℃ for 4 hours.

[0054] The composition of catalyst #1 is 30% CuO-60% ZnO-2% Li2SiO3-8% SiO2.

[0055] Catalyst Reduction: Catalyst #1 was loaded into a fixed-bed hydrogenation reactor, with a loading volume of 50 ml. First, the reactor temperature was raised to 150°C, and a mixture of hydrogen and nitrogen (5v% H2 by volume) was introduced for pre-reduction for 1 hour. Then, the hydrogen content in the hydrogen-nitrogen mixture was gradually increased to 10v% and 50v%, controlling the catalyst bed hot spot temperature to not exceed 220°C. Reduction was carried out for 3 hours in a pure hydrogen atmosphere, followed by further reduction with pure hydrogen gas to 400°C for 1 hour. The gas hourly space velocity (VHSV) was 500 h⁻¹. -1 .

[0056] Evaluation conditions: Catalyst loading 50 ml, operation at atmospheric pressure, nitrogen as carrier gas, cyclododecyl alcohol feed space velocity = 0.5 h⁻¹ -1 The reaction temperature was 220℃, the conversion rate of cyclododecyl alcohol was 98.2%, the selectivity of cyclododecone was 99.7%, the selectivity of cyclododecene was 0.09%, and the selectivity of cyclododecane was 0.05%.

[0057] Example 2

[0058] Dissolve 105.7g of copper nitrate trihydrate and 193.9g of zinc nitrate hexahydrate in 1050ml of water to prepare a 1M salt solution. Dissolve 127g of sodium carbonate in water to prepare 850g of a 15wt% sodium carbonate aqueous solution. Add 4.67g of LiOH·H2O and mix the solutions thoroughly.

[0059] Add 100g of water to the reactor, and add the above-prepared salt solution, alkaline precipitant and 33.38g of silica sol to the reactor in parallel. Control the precipitation time to 1 hour, the precipitation temperature to 75℃, and the precipitation pH to 6.5.

[0060] The obtained slurry was aged for 3.5 hours at a controlled aging temperature of 80°C. After aging for 1 hour, 60g of condensed aluminum phosphate aqueous solution was added. The mass content of condensed aluminum phosphate was 5%. The aging continued until the predetermined time was reached.

[0061] The aged slurry was filtered and washed to obtain a filter cake; the filter cake was dried at 100°C for 3 hours and calcined at 350°C for 3 hours to obtain a catalyst.

[0062] The obtained catalyst was added to a binder and extruded into 3mm diameter clover catalyst to obtain 3*2-8mm clover catalyst. The catalyst was loaded into a reactor, heated to 110℃, and purged with air for 2 hours to dry the catalyst. Then, it was treated with steam at the same temperature for 2 hours, heated to 140℃ for 2 hours, further heated to 200℃ and treated with steam for 2 hours, cooled to 100℃ and air-dried for 2 hours, and then discharged from the reactor and calcined at 350℃ for 3 hours.

[0063] The composition of catalyst #2 is 35% CuO-50% ZnO-5% Li2SiO3-10% SiO2.

[0064] Catalyst Reduction: Catalyst #2 was loaded into a fixed-bed hydrogenation reactor at a loading volume of 50 ml. First, the reactor temperature was raised to 150°C, and a mixture of hydrogen and nitrogen (5v% H2 by volume) was introduced for pre-reduction for 1 hour. Then, the hydrogen content in the hydrogen-nitrogen mixture was gradually increased to 10v% and 50v%, controlling the catalyst bed hot spot temperature to not exceed 220°C. Reduction was carried out for 3 hours in a pure hydrogen atmosphere, followed by further reduction with pure hydrogen gas to 400°C for 1 hour. The gas hourly space velocity (VHSV) was 500 h⁻¹. -1 .

[0065] Evaluation conditions: Catalyst loading 50 ml, operation at atmospheric pressure, nitrogen as carrier gas, cyclododecyl alcohol feed space velocity = 0.5 h⁻¹ -1 The reaction temperature was 220℃, the conversion rate of cyclododecyl alcohol was 98.1%, the selectivity of cyclododecone was 99.8%, the selectivity of cyclododecene was 0.07%, and the selectivity of cyclododecane was 0.06%.

[0066] Example 3

[0067] Dissolve 120.8g of copper nitrate trihydrate and 155.1g of zinc nitrate hexahydrate in 1325ml of water to prepare a 0.75M salt solution. Dissolve 119.2g of sodium carbonate in water to prepare a 700g 17wt% sodium carbonate aqueous solution. Add 4.67g of LiOH·H2O and mix the solutions thoroughly.

[0068] Add 100g of water to the reactor, and add the above-prepared salt solution, alkaline precipitant and 45.88g of silica sol to the reactor in parallel. Control the precipitation time to 1 hour, the precipitation temperature to 75℃, and the precipitation pH to 6.5.

[0069] The slurry was aged for 3 hours at a controlled aging temperature of 80°C. After aging for 1 hour, 60g of condensed aluminum phosphate aqueous solution was added. The mass content of condensed aluminum phosphate was 5%. The aging continued until the predetermined time was reached.

[0070] The aged slurry was filtered and washed to obtain a filter cake; the filter cake was dried at 100°C for 3 hours and calcined at 350°C for 3 hours to obtain a catalyst.

[0071] The obtained catalyst was added to a binder and extruded into 3mm diameter clover catalyst to obtain 3*2-8mm clover catalyst. The catalyst was loaded into a reactor, heated to 130℃, and purged with air for 1 hour to dry the catalyst. Then, it was treated with steam at the same temperature for 1 hour, heated to 170℃ for 1 hour, further heated to 230℃ and treated with steam for 1 hour, cooled to 120℃ and air-dried for 2 hours, and then discharged from the reactor and calcined at 350℃ for 3 hours.

[0072] The composition of catalyst #3 is 40% CuO-40% ZnO-5% Li2SiO3-15% SiO2.

[0073] Catalyst Reduction: Catalyst #3 was loaded into a fixed-bed hydrogenation reactor at a loading volume of 50 ml. First, the reactor temperature was raised to 150°C, and a mixture of hydrogen and nitrogen containing 5% H2 (v / v) was introduced for pre-reduction for 1 hour. Then, the hydrogen content in the hydrogen-nitrogen mixture was gradually increased to 10% and 50% v / v, controlling the catalyst bed hot spot temperature to not exceed 220°C. Reduction was carried out for 3 hours in a pure hydrogen atmosphere, followed by further reduction with pure hydrogen gas to 400°C for 1 hour. The gas hourly space velocity (VHSV) was 500 h⁻¹. -1 .

[0074] Evaluation conditions: Catalyst loading 50 ml, operation at atmospheric pressure, nitrogen as carrier gas, cyclododecyl alcohol feed space velocity = 0.5 h⁻¹ -1 The reaction temperature was 220℃, the conversion rate of cyclododecyl alcohol was 99.1%, the selectivity of cyclododecone was 99.6%, the selectivity of cyclododecene was 0.15%, and the selectivity of cyclododecane was 0.14%.

[0075] Stability data can be found Figure 1 .

[0076] Example 4

[0077] Dissolve 135.9g of copper nitrate trihydrate and 174.5g of zinc nitrate hexahydrate in 2250ml of water to prepare a 0.5M salt solution. Dissolve 134.1g of sodium carbonate in water to prepare a 610g 22wt% sodium carbonate aqueous solution. Add 1.87g of LiOH·H2O and mix the solutions thoroughly.

[0078] Add 100g of water to the reactor, and add the above-prepared salt solution, alkaline precipitant and 23.35g of silica sol to the reactor in parallel. Control the precipitation time to 2h, the precipitation temperature to 65℃, and the precipitation pH to 7.0.

[0079] The slurry was aged for 2 hours at a controlled aging temperature of 70°C. After aging for 1 hour, 20g of condensed aluminum phosphate aqueous solution was added. The mass content of condensed aluminum phosphate was 5%. The aging continued until the predetermined time was reached.

[0080] The aged slurry was filtered and washed to obtain a filter cake; the filter cake was dried at 120°C for 2 hours and calcined at 300°C for 2 hours to obtain a catalyst.

[0081] The obtained catalyst was added to a binder and extruded into a 3mm diameter clover catalyst to obtain a 3*2-8mm clover catalyst. The catalyst was loaded into a reactor, heated to 120℃, and purged with air for 1 hour to dry the catalyst. Then, it was treated with steam at the same temperature for 2 hours, heated to 150℃ for 2 hours, further heated to 200℃ and treated with steam for 2 hours, cooled to 120℃ and air-dried for 1 hour, and then discharged from the reactor and calcined at 300℃ for 2 hours.

[0082] The composition of catalyst #4 is 45% CuO-45% ZnO-2% Li2SiO3-8% SiO2.

[0083] Catalyst Reduction: Catalyst #4 was loaded into a fixed-bed hydrogenation reactor at a loading volume of 50 ml. First, the reactor temperature was raised to 150°C, and a mixture of hydrogen and nitrogen (5v% H2 by volume) was introduced for pre-reduction for 1 hour. Then, the hydrogen content in the hydrogen-nitrogen mixture was gradually increased to 10v% and 50v%, controlling the catalyst bed hot spot temperature to not exceed 220°C. Reduction was carried out for 3 hours in a pure hydrogen atmosphere, followed by further reduction with pure hydrogen to 400°C for 1 hour. The gas hourly space velocity (VHSV) was 500 h⁻¹. -1 .

[0084] Evaluation conditions: Catalyst loading 50 ml, operation at atmospheric pressure, nitrogen as carrier gas, cyclododecyl alcohol feed space velocity = 0.5 h⁻¹-1 The reaction temperature was 220℃, the conversion rate of cyclododecyl alcohol was 97.9%, the selectivity of cyclododecone was 99.8%, the selectivity of cyclododecene was 0.10%, and the selectivity of cyclododecane was 0.05%.

[0085] Example 5

[0086] Dissolve 90.6g of copper nitrate trihydrate and 182.2g of zinc nitrate hexahydrate in 1910ml of water to prepare a 0.5M salt solution. Dissolve 115.3g of sodium carbonate in water to prepare a 460g 25wt% sodium carbonate aqueous solution. Add 2.8g of LiOH·H2O and mix the solutions thoroughly.

[0087] Add 100g of water to the reactor, and add the above-prepared salt solution, alkaline precipitant and 55.02g of silica sol to the reactor in parallel. Control the precipitation time to 3h, the precipitation temperature to 65℃, and the precipitation pH to 7.0.

[0088] The slurry was aged for 2 hours at a controlled aging temperature of 75°C. After aging for 1 hour, 40g of condensed aluminum phosphate aqueous solution was added. The mass content of condensed aluminum phosphate was 5%. The aging continued until the predetermined time was reached.

[0089] The aged slurry was filtered and washed to obtain a filter cake; the filter cake was dried at 120°C for 2 hours and calcined at 320°C for 2 hours to obtain a catalyst.

[0090] The obtained catalyst was added to a binder and extruded into 3mm diameter clover catalysts to obtain 3*2-8mm clover catalysts. The catalyst was loaded into a reactor, heated to 120℃, and purged with air for 1 hour to dry the catalyst. Then, it was treated with steam at the same temperature for 2 hours, heated to 150℃ for 2 hours, further heated to 200℃ and treated with steam for 2 hours, cooled to 110℃ and air-dried for 3 hours, and then discharged from the reactor and calcined at 320℃ for 2 hours.

[0091] The composition of catalyst #5 is 30% CuO-47% ZnO-3% Li2SiO3-20% SiO2.

[0092] Catalyst Reduction: Catalyst #4 was loaded into a fixed-bed hydrogenation reactor at a loading volume of 50 ml. First, the reactor temperature was raised to 150°C, and a mixture of hydrogen and nitrogen (5v% H2 by volume) was introduced for pre-reduction for 1 hour. Then, the hydrogen content in the hydrogen-nitrogen mixture was gradually increased to 10v% and 50v%, controlling the catalyst bed hot spot temperature to not exceed 220°C. Reduction was carried out for 3 hours in a pure hydrogen atmosphere, followed by further reduction with pure hydrogen to 400°C for 1 hour. The gas hourly space velocity (VHSV) was 500 h⁻¹. -1 .

[0093] Evaluation conditions: Catalyst loading 50 ml, operation at atmospheric pressure, nitrogen as carrier gas, cyclododecyl alcohol feed space velocity = 0.5 h⁻¹ -1 The reaction temperature was 220℃, the conversion rate of cyclododecyl alcohol was 98.5%, the selectivity of cyclododecone was 99.7%, the selectivity of cyclododecene was 0.12%, and the selectivity of cyclododecane was 0.09%.

[0094] Comparative Example 1

[0095] Compared with Example 1, the difference is that Li is not added, and only a copper-zinc-silicon system catalyst is used.

[0096] Dissolve 120.8g of copper nitrate trihydrate and 155.1g of zinc nitrate hexahydrate in 1325ml of water to prepare a 0.75M salt solution. Dissolve 119.2g of sodium carbonate in water to prepare a 700g 17wt% sodium carbonate aqueous solution.

[0097] Add 100g of water to the reactor, and add the above-prepared salt solution, alkaline precipitant and 50g of silica sol to the reactor in parallel. Control the precipitation time to 1 hour, the precipitation temperature to 75℃, and the precipitation pH to 6.5.

[0098] The obtained slurry was aged for 3 hours at a controlled aging temperature of 80°C. The aged slurry was then filtered and washed to obtain a filter cake. The filter cake was dried at 80°C for 3 hours and calcined at 350°C for 3 hours to obtain the catalyst.

[0099] The obtained catalyst was added to a binder and extruded into 3mm diameter clover catalyst to obtain 3*2-8mm clover catalyst. The catalyst was loaded into a reactor, heated to 130℃, and purged with air for 1 hour to dry the catalyst. Then, it was treated with steam at the same temperature for 1 hour, heated to 170℃ for 1 hour, further heated to 230℃ and treated with steam for 1 hour, cooled to 120℃ and air-dried for 2 hours, and then discharged from the reactor and calcined at 350℃ for 3 hours.

[0100] Catalyst #6 has a composition of 40% CuO-40% ZnO-20% SiO2.

[0101] Catalyst Reduction: Catalyst #6 was loaded into a fixed-bed hydrogenation reactor at a loading volume of 50 ml. First, the reactor temperature was raised to 150°C, and a mixture of hydrogen and nitrogen (5v% H2 by volume) was introduced for pre-reduction for 1 hour. Then, the hydrogen content in the hydrogen-nitrogen mixture was gradually increased to 10v% and 50v%, controlling the catalyst bed hotspot temperature to not exceed 220°C. Reduction was carried out for 3 hours in a pure hydrogen atmosphere, followed by further reduction with pure hydrogen gas to 400°C for 1 hour. The gas hourly space velocity (VHSV) was 500 h⁻¹. -1 .

[0102] Evaluation conditions: Catalyst loading 50 ml, operation at atmospheric pressure, nitrogen as carrier gas, cyclododecyl alcohol feed space velocity = 0.5 h⁻¹ -1 The reaction temperature was 220℃, the conversion rate of cyclododecyl alcohol was 97.7%, the selectivity of cyclododecone was 97.2%, the selectivity of cyclododecene was 1.30%, and the selectivity of cyclododecane was 0.90%.

[0103] Comparative Example 2

[0104] Compared with Example 2, the difference lies in the waterless treatment process.

[0105] Dissolve 120.8g of copper nitrate trihydrate and 155.1g of zinc nitrate hexahydrate in 1325ml of water to prepare a 0.75M salt solution. Dissolve 119.2g of sodium carbonate in water to prepare a 700g 17wt% sodium carbonate aqueous solution. Add 4.67g of LiOH·H2O and mix the solutions thoroughly.

[0106] Add 100g of water to the reactor, and add the above-prepared salt solution, alkaline precipitant and 45.88g of silica sol to the reactor in parallel. Control the precipitation time to 1 hour, the precipitation temperature to 75℃, and the precipitation pH to 6.5.

[0107] The slurry was aged for 3 hours at a controlled aging temperature of 80°C. After aging for 1 hour, 60g of condensed aluminum phosphate aqueous solution was added. The mass content of condensed aluminum phosphate was 5%. The aging continued until the predetermined time was reached.

[0108] The aged slurry was filtered and washed to obtain a filter cake; the filter cake was dried at 100℃ for 3 hours and calcined at 350℃ for 3 hours to obtain a catalyst.

[0109] The composition of catalyst #7 is 40% CuO-40% ZnO-5% Li2SiO3-15% SiO2.

[0110] Catalyst reduction: Catalyst #7 was loaded into a fixed-bed hydrogenation reactor at a loading volume of 50 ml. First, the reactor temperature was raised to 150°C, and a mixture of hydrogen and nitrogen (5v% H2 by volume) was introduced for pre-reduction for 1 hour. Then, the hydrogen content in the hydrogen-nitrogen mixture was gradually increased to 10v% and 50v%, controlling the catalyst bed hot spot temperature to not exceed 220°C. Reduction was carried out for 3 hours in a pure hydrogen atmosphere, followed by further reduction with pure hydrogen gas to 400°C for 1 hour. The gas hourly space velocity (VHSV) was 500 h⁻¹. -1 .

[0111] Evaluation conditions: Catalyst loading 50 ml, operation at atmospheric pressure, nitrogen as carrier gas, cyclododecyl alcohol feed space velocity = 0.5 h⁻¹ -1The reaction temperature was 220℃, the conversion rate of cyclododecyl alcohol was 99.1%, the selectivity of cyclododecone was 99.6%, the selectivity of cyclododecene was 0.15%, and the selectivity of cyclododecane was 0.14%.

[0112] Comparative Example 3

[0113] Compared with Example 3, the difference is that condensed aluminum phosphate is not added.

[0114] Dissolve 120.8g of copper nitrate trihydrate and 155.1g of zinc nitrate hexahydrate in 1325ml of water to prepare a 0.75M salt solution. Dissolve 119.2g of sodium carbonate in water to prepare a 700g 17wt% sodium carbonate aqueous solution. Add 4.67g of LiOH·H2O and mix the solutions thoroughly.

[0115] Add 100g of water to the reactor, and add the above-prepared salt solution, alkaline precipitant and 45.88g of silica sol to the reactor in parallel. Control the precipitation time to 1 hour, the precipitation temperature to 75℃, and the precipitation pH to 6.5.

[0116] The obtained slurry was aged for 3 hours at a controlled aging temperature of 80°C. The aged slurry was then filtered and washed to obtain a filter cake. The filter cake was dried at 80°C for 3 hours and calcined at 350°C for 3 hours to obtain the catalyst.

[0117] The obtained catalyst was added to a binder and extruded into 3mm diameter clover catalyst to obtain 3*2-8mm clover catalyst. The catalyst was loaded into a reactor, heated to 130℃, and purged with air for 1 hour to dry the catalyst. Then, it was treated with steam at the same temperature for 1 hour, heated to 170℃ for 1 hour, further heated to 230℃ and treated with steam for 1 hour, cooled to 120℃ and air-dried for 2 hours, and then discharged from the reactor and calcined at 350℃ for 3 hours.

[0118] The composition of catalyst #3 is 40% CuO-40% ZnO-5% Li2SiO3-15% SiO2.

[0119] Catalyst Reduction: Catalyst #3 was loaded into a fixed-bed hydrogenation reactor at a loading volume of 50 ml. First, the reactor temperature was raised to 150°C, and a mixture of hydrogen and nitrogen containing 5% H2 (v / v) was introduced for pre-reduction for 1 hour. Then, the hydrogen content in the hydrogen-nitrogen mixture was gradually increased to 10% and 50% v / v, controlling the catalyst bed hot spot temperature to not exceed 220°C. Reduction was carried out for 3 hours in a pure hydrogen atmosphere, followed by further reduction with pure hydrogen gas to 400°C for 1 hour. The gas hourly space velocity (VHSV) was 500 h⁻¹. -1 .

[0120] Evaluation conditions: Catalyst loading 50 ml, operation at atmospheric pressure, nitrogen as carrier gas, cyclododecyl alcohol feed space velocity = 0.5 h⁻¹ -1 The reaction temperature was 220℃, the conversion rate of cyclododecyl alcohol was 98.4%, the selectivity of cyclododecone was 99.6%, the selectivity of cyclododecene was 0.17%, and the selectivity of cyclododecane was 0.10%.

[0121] Stability data can be found Figure 1 .

Claims

1. A dehydrogenation catalyst for the production of aldehydes or ketones by hydroxydehydrogenation, characterized in that, The catalyst comprises the following components: Copper oxide 30-45wt%; Zinc oxide 45-60wt%; Silicon dioxide 8-20wt%; Lithium silicate 1-5wt%; Based on the weight of the catalyst. The preparation method of the catalyst comprises the following steps: S1: Dissolve copper salt and zinc salt in water to prepare a salt solution, prepare an aqueous solution of an alkaline precipitant, and add a lithium-containing compound; S2: Add water to a reactor, and add the salt solution, a silicon source, and the alkaline precipitant to the reactor for precipitation; S3: After aging, add an additive aqueous solution and continue aging; S4: Filter and wash the slurry of S3 to obtain a filter cake, dry and calcine to obtain the catalyst; S5: After adding a binder to the catalyst and extruding, load into a reactor, treat with steam, and calcine to obtain the target catalyst. The additive of S3 is condensed aluminum phosphate and / or aluminum dihydrogen tripolyphosphate.

2. The method of claim 1, wherein, The catalyst comprises the following components: Copper oxide 30-40wt%; Zinc oxide 45-55wt%; Silicon dioxide 12-20wt%; Lithium silicate 1-3wt%; Based on the weight of the catalyst.

3. The method of claim 2, wherein, The catalyst comprises the following components: Copper oxide 30-40wt%; Zinc oxide 45-55wt%; Silicon dioxide 12-20wt%; Lithium silicate 1-3wt%; Based on the weight of the catalyst.

4. A process for the preparation of a catalyst according to any one of claims 1 to 3, characterized in that The preparation method comprises the following steps: S1: Dissolve copper salt and zinc salt in water to prepare a salt solution, prepare an aqueous solution of an alkaline precipitant, and add a lithium-containing compound; S2: Add water to a reactor, and add the salt solution, a silicon source, and the alkaline precipitant to the reactor for precipitation; S3: After aging, add an additive aqueous solution and continue aging; S4: Filter and wash the slurry of S3 to obtain a filter cake, dry and calcine to obtain the catalyst; S5: After adding a binder to the catalyst and extruding, load into a reactor, treat with steam, and calcine to obtain the target catalyst.

5. The method of claim 4, wherein, The copper salt of S1 is selected from one or more of copper nitrate, copper chloride, and copper acetate; and / or, the zinc salt of S1 is selected from one or more of zinc nitrate, zinc chloride, and zinc acetate; and / or, the silicon source of S1 is silica sol and / or sodium silicate; and / or, the lithium-containing compound of S1 is lithium hydroxide and / or lithium nitrate; and / or, the concentration of the salt solution of S1 is 0.5-1M; and / or, the alkaline precipitant of S1 is one or more of sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, sodium hydroxide, potassium hydroxide, ammonium carbonate, ammonium bicarbonate, and ammonia.

6. The method of claim 5, wherein, The silicon source of S1 is silica sol; and / or, the lithium-containing compound of S1 is lithium hydroxide.

7. The method of claim 4, wherein, The precipitation temperature of S2 is 55-75°C, and the pH value is 6.5-8.

0.

8. The method of claim 7, wherein, The precipitation temperature of S2 is 62-72°C, and the pH value is 6.8-7.

5.

9. The method of claim 4, wherein, The aging time of S3 is 2-4h, and the aging temperature is 65-80°C; and / or, the additive of S3 is condensed aluminum phosphate and / or aluminum dihydrogen tripolyphosphate.

10. The method of claim 9, wherein, The aging temperature of S3 is 68-78°C; The addition amount of the additive of S3 is 1-3% of the total weight of the catalyst; The additive aqueous solution of S3 is added after aging for 1h.

11. The method of claim 4, wherein, The calcination temperature of the filter cake S4 is 260-330℃, and the calcination time is 3-12h.

12. The method of claim 11, wherein, The calcination temperature of the filter cake S4 is 280-320℃, and the calcination time is 4-8h.

13. The method of claim 4, wherein, The treatment mode S5 is that after the catalyst is loaded into the reactor, it is first heated to 110-130℃, air is blown for 1-2h to dry the catalyst, then the same temperature is maintained, water vapor is introduced for 1-2h, the temperature is increased to 140-170h for 1-2h, the temperature is further increased to 200-230℃, water vapor is introduced for 1-2h, and the temperature is decreased to 100-120℃, and air is dried for 1-3h. And / or, the calcination S5 is 280-350℃ calcination for 2-4h.

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