Catalyst for preparing 1-decene through dehydration of n-decanol and application of catalyst

Abstract

The invention discloses a catalyst for preparing 1-decene through dehydration of n-decanol, which is characterized in that the catalyst contains alumina, and the preparation step of the catalyst comprises the step of modifying the alumina by using an oxygen-containing organic matter. The invention also provides application of the catalyst in preparation of 1-decene through dehydration of n-decanol, and by using the technology provided by the invention, relatively high selectivity and yield of the target product 1-decene can be obtained.

Description

Technical Field

[0001] The present invention belongs to the technical field of catalysts, and particularly relates to a catalyst for the dehydration of n-decanol to 1-decene and its application. Background Art

[0002] 1-Decene is mainly used as a raw material for the production of fine chemicals such as polyalphaolefin synthetic lubricant base oils, comonomers, detergents, and plasticizers.

[0003] Currently, the monomer used for the production of polyalphaolefins is mainly 1-decene. After 1-decene oligomerizes and hydrogenates, it is used as a base oil and an additive for lubricants, and can be widely used as automotive lubricants, engine oils, gear oils, and transmission fluids. Compared with other synthetic lubricants, the polymer oil synthesized from 1-decene has excellent performance in terms of rubber swelling, low-temperature torque, evaporation loss, etc., and is considered to be a high-quality lubricant that can be used in a wide temperature range. The polymer oil synthesized from 1-decene has a low low-temperature viscosity as an engine oil, good stability against repeated shear, heat resistance, and anti-aging properties, which is conducive to engine starting, reduces the power consumption of the battery for operating wear, and can also be continuously used for a long time without frequent replacement of the engine oil. The polymer oil synthesized from 1-decene can be formulated into automotive multi-grade gear oils without adding any viscosity index improvers, can meet the viscosity index requirements for shear performance, and is suitable for multi-grade vehicle gear oils and military gear oils required in alpine regions. The polymer oil synthesized from 1-decene has both the best low-temperature and high-temperature performance and can extend the service life of engine oil and other special liquids. Since the 1970s, 1-decene polymer oil has been widely used in industries such as aviation, military, and automotive, and many well-known advanced lubricant base oil producers in the world use 1-decene as a basic raw material.

[0004] 1-Decene can also be used as a comonomer to produce modified polyethylene and various special-purpose resins, such as making linear low-density polyethylene (LLDPE) with better toughness and thinner thickness. In addition, 1-decene can be used as a non-conjugated monomer to produce ethylene-propylene rubber comonomers and produce random copolymer rubbers, and can be used as a comonomer to produce syndiotactic polypropylene resins.

[0005] 1-Decene can be used to produce straight-chain linear plasticizers and stabilizers for polyvinyl chloride (PVC), etc., and is suitable for low-temperature crack resistance and high-temperature volatilization degradation of PVC, such as for roof coverings, wire and cable sheaths, waterproof tarpaulins, etc.

[0006] The ester formed by the reaction of the 1,2-epoxide obtained by the epoxidation reaction of 1-decene with an organic acid can be used as a plasticizer and a lubricant, and the freezing point can reach -60°C. In addition, the reaction product of the epoxide and a polyol can be used as a smoothing agent and an antistatic agent for synthetic resins.

[0007] The product obtained from the direct esterification reaction of 1-decene with organic acids can be used in the production of diester plasticizers. This product is used as a solvent for cellulose acetate, cellulose nitrate, animal and vegetable oils, and synthetic resins, and can also be used in the preparation of plastics, leather paints, and fragrances. The phthalate plasticizers synthesized from 1-decene are far superior to dioctyl phthalate (DOP) in terms of low-temperature cracking resistance, high-temperature degradation resistance, and plasticizer volatility resistance, and are particularly suitable for use in car interior trim parts and wire and cable sleeves, etc.

[0008] 1-Decene can be used as a non-toxic biodegradable well fluid. It not only has good biodegradability but is also non-toxic to marine organisms and can meet the viscosity and pour point technical requirements for formulating oil-based muds.

[0009] 1-Decene polymers can be used as flow improvers for crude oil, etc. in oil pipeline pumping stations to reduce the wall blocking effect and improve the pipeline transportation efficiency.

[0010] The main industrial methods for producing 1-decene are wax cracking and ethylene oligomerization.

[0011] Before using the oligomerization route to produce linear α-olefins such as 1-decene, 1-decene was produced by cracking waxy hydrocarbons in crude oil. The carbon number distribution of typical saponified wax cracked α-olefins is as follows: the mass percentage of 1-hexene product is 0.02%, the 1-heptene product is 0.16%, the 1-octene product is 0.62%, the 1-nonene product is 9.81%, and the 1-decene product is 33.6%. Due to the complex product components and low 1-decene selectivity, the paraffin cracking method lacks competitiveness in terms of economy and product quality and has gradually been replaced by the ethylene oligomerization method in industrial production.

[0012] The main typical processes of ethylene oligomerization are as follows:

[0013] The device for directly oligomerizing ethylene to produce linear α-olefins such as 1-decene was first built by the US Guff Company in Texas in 1964, with a production capacity of 60,000 t / a. Later, the Chevron Company used this method for production, and the chain growth reaction and chain displacement reaction were completed in one step. The products of the Chevron Company follow a normal distribution, among which the mass fraction of 1-butene product is 13.9%, the 1-hexene product is 14.5%, the 1-octene product is 13.6%, and the 1-decene product is 11.9%.

[0014] The AIphaselect process was developed by IFP of France based on the ethylene trimerization to 1-butene (AI-Phabutol process). Through catalyst modification, the contents of components such as 1-hexene and 1-octene were increased. The mass fraction of its 1-butene product is 33% - 34%, the 1-hexene product is 30% - 32%, the 1-octene product is 17% - 21%, and the 1-decene product is 9% - 14%.

[0015] The production process developed by Saudi Basic Industries Corporation (SABIC) has a catalyst composed of a complex, a nickel compound, an activator, and silica. Using ethylene as the raw material and a slurry reactor, the ethylene conversion rate can reach 49%. Among them, the mass percentage of the 1-butene product is 31%, the 1-hexene product is 33%, the 1-octene product is 19%, and 1-decene is 13%. The purities of the 1-butene, 1-hexene, 1-octene, and 1-decene products obtained by separation are 99%, 99.2%, 98.2%, and 96.9% respectively.

[0016] The mass percentage distribution of the main products obtained by the Ethyl process is as follows: the 1-butene product is 13.0%, the 1-hexene product is 16.0%, the 1-octene product is 19.0%, and the 1-decene product is 18.0%.

[0017] The SHOP process, namely the Shell High Olefin Process, is a production process developed by Shell in 1977. It uses a nickel-based metal complex catalyst, and the process includes three steps: ethylene oligomerization, isomerization, and disproportionation. The mass percentage distribution of the main products obtained by this process is as follows: the 1-butene product is 12.0%, the 1-hexene product is 13.0%, the 1-octene product is 12.0%, and the 1-decene product is 12.0%.

[0018] The mass percentage distribution of the main products obtained by the Linde process is as follows: the 1-butene product is 6.1%, the 1-hexene product is 6.2%, the 1-octene product is 14.2%, and the 1-decene product is 15.3%.

[0019] The main components of the Sasol process products are: the 1-butene product is 16.8%, the 1-pentene product is 11.7%, the 1-hexene product is 9.3%, the 1-heptene product is 7.5%, the 1-octene product is 5.6%, the 1-nonene product is 4.2%, and the 1-decene product is 2.8%.

[0020] In 1990, Phillips Company developed a new process for the trimerization of ethylene to 1 - hexene, and made significant progress in 1996. Among its process indicators, the selectivity of ethylene oligomerization to 1 - hexene is as high as 95%, and the purity is above 99%. In addition, 1 - decene is the main by - product. Among them, the content of 1 - hexene product is 94% - 95%, and the 1 - decene product is 5%.

[0021] As can be seen from the above review, even when using the ethylene oligomerization method to produce 1 - decene, the proportion of 1 - decene in the product is very small. At present, there is no separate 1 - decene production plant in the world, and it is all produced along with the production of α - olefins such as 1 - hexene and 1 - octene, which leads to the problems of high separation cost of 1 - decene products and difficulty in manufacturing high - purity products. When using n - decanol to dehydrate to produce 1 - decene under the action of a catalyst, the product is relatively single and easy to separate and purify. Compared with the existing process technical routes described above, it can have the advantages of simple process and easy separation. Separating n - decanol from the higher - carbon alcohols produced by a coal - based Fischer - Tropsch synthesis plant can provide raw materials for the dehydration of n - decanol to produce 1 - decene under the action of a catalyst.

[0022] Higher - carbon alcohol dehydration usually uses oxide catalysts, and when using alumina as the catalyst, it generally needs to be modified with alkali metals to obtain high product selectivity. The literature (Modern Chemical Industry, 2013, 42, 275 - 277) uses Nb 2 O 5 as the catalyst, and uses the principle of fatty alcohol dehydration to produce olefins to dehydrate C10 fatty alcohol to α - C10 olefin. When the reaction temperature is 290℃, the fatty alcohol dehydration is the most complete, and the maximum conversion rate of the fatty alcohol is 94%. However, the preparation process of the Nb 2 O 5 catalyst is complex and the production cost is relatively high. Chinese Patent CN112898109 A uses alumina modified with specific alkali metals as the catalyst to dehydrate higher - carbon alcohol raw materials to produce α - higher - carbon olefins. Under optimized reaction conditions, the conversion rate of α - higher - carbon alcohol is above 99%. Summary of the Invention

[0023] The present invention discloses a catalyst for the dehydration of n - decanol to 1 - decene, and the catalyst is prepared by modifying alumina with an oxygen - containing organic compound. The present invention also discloses the application of the catalyst in the process of dehydrating n - decanol to 1 - decene, which can realize the high - conversion and high - selectivity dehydration of n - decanol to 1 - decene.

[0024] The content of the present invention is elaborated in detail below:

[0025] The present invention provides a catalyst for the dehydration of n-decanol to 1-decene. The catalyst composition contains alumina, and the catalyst preparation process includes soaking the alumina with an oxygen-containing organic compound and then performing a high-temperature heat treatment in the gas phase.

[0026] The present invention also provides a preparation method of the catalyst for the dehydration of n-decanol to 1-decene, which is characterized in that the catalyst is prepared according to the following steps:

[0027] (1) After soaking and heating the alumina in an oxygen-containing organic compound under reflux at the boiling temperature for a certain period of time, the temperature is lowered to room temperature - 80°C, and the liquid-phase oxygen-containing organic compound is removed by filtration to obtain a solid-phase catalyst precursor.

[0028] (2) The catalyst precursor prepared in step (1) is further subjected to a high-temperature heat treatment in the gas phase to obtain the catalyst.

[0029] According to the catalyst for the dehydration of n-decanol to 1-decene provided by the present invention, the alumina can be commercially available activated alumina conventionally used for preparing catalysts. Optional physical property parameters of the alumina are: specific surface area is 110 - 450 m 2 / g, average pore diameter is 2.0 - 12.0 nm, and pore volume is 0.3 - 0.8 ml / g. Preferred physical property parameters of the alumina are: specific surface area is 220 - 380 m 2 / g, average pore diameter is 4.0 - 8.0 nm, and pore volume is 0.45 - 0.65 ml / g.

[0030] According to the preparation method of the catalyst for the dehydration of n-decanol to 1-decene provided by the present invention, the oxygen-containing organic compound is one or two or three of n-hexanol, cyclohexanol or phenol; the heating reflux treatment time is 1 - 8 hours, preferably 2 - 6 hours, more preferably 2 - 4 hours; the mass ratio of the oxygen-containing organic compound to the alumina is 2:1 - 10:1, preferably 3:1 - 8:1, more preferably 4:1 - 6:1. The pressure of the treatment process is normal pressure, and the treatment temperature is the boiling temperature of the oxygen-containing organic compound used.

[0031] According to the preparation method of the catalyst for the dehydration of n-decanol to 1-decene provided by the present invention, an inert gas is used in the high-temperature heat treatment in the gas phase; the high-temperature heat treatment can be carried out in a fixed-bed reactor or a tubular furnace or a box furnace; the inert gas can be one or two or three of nitrogen, argon or helium. The treatment temperature is 200 - 1100°C, preferably 400 - 1000°C, more preferably 600 - 900°C; the treatment time is 2 - 12 hours, preferably 3 - 10 hours, more preferably 4 - 8 hours; the gas hourly space velocity under an inert atmosphere is GHSV = 100 - 20000 h -1 , preferably GHSV = 200 - 10000 h-1 , more preferably GHSV = 500 - 3000 h -1 ; the pressure of the gas-phase high-temperature heat treatment is 0.1 - 2.0 MPa, preferably 0.1 - 1.0 MPa, more preferably 0.1 - 0.5 MPa; the pressure referred to in the present invention is the absolute pressure.

[0032] The present invention also provides an application of the catalyst in the process of dehydrating n-decanol to produce 1-decene, which is characterized in that the catalyst and a continuous flow fixed bed reactor are used, and n-decanol is used as a raw material to produce 1-decene; the use temperature of the catalyst is 100 - 500 °C, preferably 200 - 420 °C, more preferably 250 - 380 °C; the use pressure is 0.01 - 2.0 MPa, preferably 0.02 - 1.0 MPa, more preferably 0.03 - 0.5 MPa; the liquid-phase feed space velocity of n-decanol is LHSV = 0.02 - 1.2 h -1 , preferably 0.05 - 0.8 h -1 , more preferably 0.1 - 0.5 h -1 .

[0033] An application of the catalyst provided by the present invention in the process of dehydrating n-decanol to produce 1-decene can use nitrogen as a carrier gas to enter the reactor together with n-decanol; when using nitrogen to enter the reactor together with n-decanol, the space velocity of the nitrogen is GHSV = 200 - 5000 h -1 , preferably 300 - 3000 h -1 , more preferably 500 - 2000 h -1 .

[0034] The beneficial effects of the present invention are:

[0035] Compared with the existing catalysts for dehydrating alcohols to produce olefins, a catalyst for dehydrating n-decanol to produce 1-decene and its application disclosed by the present invention use alumina treated in an inert atmosphere of an oxygen-containing organic compound as the catalyst. Compared with alumina not treated in an inert atmosphere of an oxygen-containing organic compound, a very high selectivity and yield of 1-decene can be obtained, and the catalyst does not need to be modified by adding other inorganic auxiliaries, and the preparation process is simple, having the prospect of industrial application. Specific Embodiments

[0036] The following examples and comparative examples are used to further illustrate the present invention, but the present invention is not limited to the following examples.

[0037] Example 1

[0038] Weigh 10 g of alumina (specific surface area is 332 m 2(per gram, with an average pore diameter of 6.3 nm and a pore volume of 0.56 - ml / g) was placed in a distillation flask, and 50 g of n-hexanol was added to soak the alumina. It was heated under reflux at atmospheric pressure and the boiling temperature of n-hexanol (approximately 156 °C) for 2 hours and then cooled to 50 °C. After cooling to 50 °C, the liquid-phase n-hexanol was removed by filtration, and the solid phase was treated in a tubular furnace at 750 °C for 6 hours under a nitrogen atmosphere, with a nitrogen space velocity of GHSV = 1000 h -1 , and the nitrogen pressure was 0.15 MPa. After the treatment, it was cooled to room temperature to obtain catalyst A.

[0039] Example 2

[0040] Weigh 10 g of alumina (specific surface area: 332 m 2 / g, average pore diameter: 6.3 nm, pore volume: 0.56 - ml / g) and place it in a distillation flask. Then add 50 g of cyclohexanol to soak the alumina. Heat it under reflux at atmospheric pressure and the boiling temperature of cyclohexanol (approximately 160 °C) for 2 hours and then cool to 50 °C. After cooling to 50 °C, the liquid-phase cyclohexanol was removed by filtration, and the solid phase was treated in a tubular furnace at 750 °C for 6 hours under a nitrogen atmosphere, with a nitrogen space velocity of GHSV = 1000 h -1 , and the nitrogen pressure was 0.15 MPa. After the treatment, it was cooled to room temperature to obtain catalyst B.

[0041] Example 3

[0042] Weigh 10 g of alumina (specific surface area: 332 m 2 / g, average pore diameter: 6.3 nm, pore volume: 0.56 - ml / g) and place it in a distillation flask. Then add 50 g of phenol to soak the alumina. Heat it under reflux at atmospheric pressure and the boiling temperature of phenol (approximately 182 °C) for 2 hours and then cool to 50 °C. After cooling to 50 °C, the liquid-phase phenol was removed by filtration at 50 °C, and the solid phase was treated in a tubular furnace at 750 °C for 6 hours under a nitrogen atmosphere, with a nitrogen space velocity of GHSV = 1000 h -1 , and the nitrogen pressure was 0.15 MPa. After the treatment, it was cooled to room temperature to obtain catalyst C.

[0043] Example 4

[0044] Weigh 10 g of alumina (specific surface area: 332 m 2 / g, average pore diameter: 6.3 nm, pore volume: 0.56 - ml / g) and place it in a distillation flask. Then add 50 g of phenol to soak the alumina. Heat it under reflux at atmospheric pressure and the boiling temperature of phenol (approximately 182 °C) for 4 hours and then cool to 50 °C. After cooling to 50 °C, the liquid-phase phenol was removed by filtration at 50 °C, and the solid phase was treated in a tubular furnace at 750 °C for 6 hours under a nitrogen atmosphere, with a nitrogen space velocity of GHSV = 1000 h -1, the nitrogen pressure is 0.15 MPa, and after the treatment is completed, it is cooled to room temperature to obtain catalyst D.

[0045] Example 5

[0046] Weigh 10 g of alumina (specific surface area is 332 m 2 / g, average pore diameter is 6.3 nm, pore volume is 0.56 - ml / g) and put it into a distillation flask. Then add 50 g of phenol to soak the alumina. Heat and reflux at atmospheric pressure and the boiling point temperature of phenol (approx. 182 °C) for 4 hours, and then cool to 50 °C. After cooling to 50 °C, filter to remove the liquid-phase phenol at 50 °C. The solid phase is treated in a tubular furnace under a nitrogen atmosphere at 850 °C for 6 hours, and the nitrogen space velocity is GHSV = 1000 h -1 , the nitrogen pressure is 0.15 MPa, and after the treatment is completed, it is cooled to room temperature to obtain catalyst E.

[0047] Example 6

[0048] Weigh 10 g of alumina (specific surface area is 332 m 2 / g, average pore diameter is 6.3 nm, pore volume is 0.56 - ml / g) and put it into a distillation flask. Then add 50 g of phenol to soak the alumina. Heat and reflux at atmospheric pressure and the boiling point temperature of phenol (approx. 182 °C) for 4 hours, and then cool to 50 °C. After cooling to 50 °C, filter to remove the liquid-phase phenol at 50 °C. The solid phase is treated in a tubular furnace under a nitrogen atmosphere at 650 °C for 12 hours, and the nitrogen space velocity is GHSV = 1000 h -1 , the nitrogen pressure is 0.15 MPa, and after the treatment is completed, it is cooled to room temperature to obtain catalyst F.

[0049] Comparative Example 1

[0050] Weigh 10 g of alumina (specific surface area is 332 m 2 / g, average pore diameter is 6.3 nm, pore volume is 0.56 - ml / g) and put it into a distillation flask. Then add 50 g of phenol to soak the alumina. Heat and reflux at atmospheric pressure and the boiling point temperature of phenol (approx. 182 °C) for 4 hours, and then cool to 50 °C. After cooling to 50 °C, filter to remove the liquid-phase phenol at 50 °C. The solid phase is treated in a tubular furnace under an air atmosphere at 750 °C for 6 hours, and the air space velocity is GHSV = 1000 h -1 , the air pressure is 0.15 MPa, and after the treatment is completed, it is cooled to room temperature to obtain catalyst G.

[0051] Comparative Example 2

[0052] Weigh 10 g of alumina (specific surface area is 332 m 2 / g, with an average pore diameter of 6.3 nm and a pore volume of 0.56 - ml / g), was treated in a tubular furnace at 750 °C for 6 hours under a nitrogen atmosphere, with a nitrogen space velocity of GHSV = 1000 h -1 , a nitrogen pressure of 0.15 MPa, and after the treatment, it was cooled to room temperature to obtain catalyst H.

[0053] The reaction evaluation experiment of the catalyst prepared according to the above scheme for the dehydration of n-decanol to 1-decene was carried out in a fixed-bed tubular reactor. The reaction conditions were as follows: the catalyst loading was 1.0 g, the reaction pressure was 0.3 MPa, the reaction temperature was 300 °C, and the liquid hourly space velocity of the n-decanol feed was 0.3 h -1 , and the gas hourly space velocity of nitrogen (as the carrier gas) was 700 h -1 . After the reaction products were cooled and collected, they were analyzed by an Alilent 8890 gas chromatograph equipped with an HP-5 capillary column.

[0054] The reaction evaluation results of the catalysts of different examples and comparative examples obtained by the above method for the dehydration of n-decanol to 1-decene are listed in Table 1.

[0055] Table 1 Reaction evaluation results of the dehydration of n-decanol to 1-decene

[0056]

[0057] As can be seen from the above comparative examples and examples, the catalyst provided by the present invention exhibits excellent activity, selectivity, and stability in the reaction of dehydrating n-decanol to 1-decene, and has good application prospects.

Claims

1. A catalyst for dehydrating n-decyl alcohol to 1-decene, characterized in that: The catalyst is prepared by the following process: firstly, aluminum oxide is soaked with oxygen-containing organic matter, and then the soaked aluminum oxide is subjected to gas phase high-temperature heat treatment to obtain the desired catalyst; the gas phase high-temperature heat treatment process is carried out in an inert atmosphere gas.

2. The catalyst according to claim 1, characterized in that The oxygen-containing organic matter is one, two or three of n-hexanol, cyclohexanol or phenol.

3. The catalyst according to claim 1, characterized in that The inert gas may be one, two or three of nitrogen, argon or helium.

4. The catalyst according to any one of claims 1 to 3, characterized in that The catalyst was prepared according to the following steps: (1) soaking aluminum oxide in the oxygen-containing organic matter at the boiling temperature of the oxygen-containing organic matter, heating and refluxing, and then filtering to remove the liquid oxygen-containing organic matter to obtain a solid phase catalyst precursor; the heating and refluxing treatment time is 1-8 hours, preferably 2-6 hours, more preferably 2-4 hours; the mass ratio of the oxygen-containing organic matter to the aluminum oxide is 2:1 to 10:1, preferably 3:1 to 8:1, more preferably 4:1 to 6:1; (2) subjecting the catalyst precursor prepared in step (1) to a gas phase high temperature heat treatment under an inert atmosphere to obtain the catalyst; the high temperature heat treatment can be carried out in a fixed bed reactor, a tube furnace or a box furnace; the treatment temperature is 200 to 1100° C., preferably 400 to 1000° C., more preferably 600 to 900° C.; the treatment time is 2 to 12 hours, preferably 3 to 10 hours, more preferably 4 to 8 hours; the gas space velocity under the inert atmosphere is GHSV=100 to 20,000 h -1 , preferably GHSV = 200 ~ 10000h -1 , more preferably GHSV=500~3000h -1 ; The pressure of the gas phase high temperature heat treatment is 0.1 to 2.0 MPa, preferably 0.1 to 1.0 MPa, and more preferably 0.1 to 0.5 MPa.

5. The catalyst according to claim 1 or 4, characterized in that The physical properties of the optional alumina are: specific surface area of ​​110 to 450 m 2 / g, average pore diameter is 2.0~12.0nm, pore volume is 0.3~0.8ml / g; The preferred physical properties of alumina are: specific surface area of ​​220 to 380 m 2 / g, the average pore diameter is 4.0~8.0nm, and the pore volume is 0.45~0.65ml / g.

6. Use of the catalyst according to any one of claims 1 to 5 in the process of catalyzing the dehydration of n-decyl alcohol to produce 1-decene.

7. Use of the catalyst according to claim 6, characterized in that: Using the catalyst and a continuous flow fixed bed reactor, 1-decene is prepared with n-decanol as a raw material; the catalyst is used at a temperature of 100 to 500° C., preferably 200 to 420° C., more preferably 250 to 380° C.; the used pressure is 0.01 to 2.0 MPa, preferably 0.02 to 1.0 MPa, more preferably 0.03 to 0.5 MPa; the liquid phase feed space velocity of n-decanol is LHSV=0.02 to 1.2 h -1 , preferably 0.05~0.8h -1 , more preferably 0.1 to 0.5h -1 .

8. Use of the catalyst according to claim 6 or 7, characterized in that: Nitrogen can also be used as a carrier gas to enter the reactor together with n-decanol; when nitrogen and n-decanol are used to enter the reactor together, the nitrogen space velocity is GHSV = 200 ~ 5000h -1 , preferably 300~3000h -1 , more preferably 500 to 2000 hours -1 .

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