A method for producing isopropanol by hydrogenating acetone
By using nickel-based catalysts and optimizing process conditions in the acetone hydrogenation reaction, the yield and selectivity of isopropanol are improved, and the production of high-purity isopropanol is achieved through the optimization of water separation and de-weighting columns, and the solution is solved. The problem of low selectivity of isopropanol in the existing process is made.
Patent Information
- Application Number
- CN202211358385.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-11-01
- Publication Date
- 2024-12-17
- Estimated Expiration
- 2042-11-01
AI Technical Summary
The current process of hydrogenating acetone isopropanol is low in the isopropanol selectivity, and the process needs to be optimized.
The acetone hydrogenation reaction is carried out under specific temperature and pressure conditions by controlling the reaction conditions and catalyst load, combining gas-liquid separation, water separation and isopropanol de-heavy steps to improve the yield of isopropanol and Selective.
The yield of isopropanol is achieved by reaching more than 85%, and the selectivity is reached more than 96%. By optimizing the operating conditions of water separation and weight removal tower, the purity of the product is improved to more than 99.5%. At the same time, the process is simple, environmentally friendly and consumption Low energy.
Abstract
Description
Technical Field
[0001] The invention relates to the field of C07C31 / 10, and in particular to a method for producing isopropanol by hydrogenating acetone. Background Art
[0002] Since most of the acetone in industry is obtained by cumene peroxidation and co-produced with phenol, due to the increase in the demand for phenol, a large amount of acetone is co-produced, resulting in an imbalance in demand, which often leads to an excess of acetone. This makes the preparation of isopropanol by acetone hydrogenation an economically feasible route.
[0003] CN111377796A discloses a process and system for producing isopropanol by hydrogenating acetone. The isopropanol production system of the patent does not require a dehydration tower and subsequent recovery equipment for aqueous isopropanol, thereby reducing device investment, simplifying the separation process, avoiding the azeotropic separation process of isopropanol and water, not producing aqueous isopropanol, and improving the total yield of the product isopropanol.
[0004] CN102391067A discloses a method for synthesizing isopropanol by hydrogenating acetone. The patent has the advantages of high catalyst selectivity, good strength, low hydrogenation reaction pressure, mild reaction conditions, and easy removal of reaction heat.
[0005] However, the isopropyl ketone obtained in the above patent has low selectivity and the process needs to be optimized. Summary of the invention
[0006] In view of the above problems, the present invention discloses a method for producing isopropanol by hydrogenating acetone, the method comprising the following steps:
[0007] S1: acetone hydrogenation;
[0008] S2: gas-liquid separation;
[0009] S3: water separation;
[0010] S4: Isopropanol decomposition.
[0011] In one embodiment, the S1 acetone hydrogenation specifically comprises: reacting acetone with hydrogen under the action of a hydrogenation catalyst to generate a material mainly composed of isopropanol and hydrogen.
[0012] Preferably, in step S1, the acetone hydrogenation temperature is 110-160°C, the pressure is 2-4 MPa, and the acetone liquid phase volume space velocity is 0.1-2 h -1 , the catalyst loading is 10-20mL.
[0013] Further preferably, the acetone hydrogenation temperature is 120°C, the pressure is 3 MPa, and the acetone liquid phase volume space velocity is 0.5 h -1, the catalyst loading was 15 mL.
[0014] In one embodiment, in the acetone hydrogenation process, the molar feed ratio of hydrogen to acetone is (1-4):1.
[0015] Preferably, in the acetone hydrogenation process, the molar feed ratio of hydrogen to acetone is 2:1.
[0016] In one embodiment, the hydrogenation catalyst is a nickel-based catalyst.
[0017] Preferably, the Ni mass loading of the nickel-based catalyst is 5-10%.
[0018] Further preferably, the Ni mass loading of the nickel-based catalyst is 8%.
[0019] In one embodiment, the nickel-based catalyst is added with an activating promoter.
[0020] Preferably, the active auxiliary agent is selected from one or more of Zn, Fe, Cu, Mg, Co, Mn, Ca, and K.
[0021] More preferably, the active auxiliary agent is Zn.
[0022] In one embodiment, the mass loading of the active auxiliary agent is 5-10 wt %.
[0023] Preferably, the mass loading amount of the active auxiliary agent is 8 wt %.
[0024] In one embodiment, the nickel-based catalyst carrier is selected from one of activated carbon, diatomaceous earth, V2O5, Al2O3, SiO2, and TiO2.
[0025] Preferably, the nickel-based catalyst carrier is activated carbon.
[0026] In one embodiment, the nickel-based catalyst needs to be activated before use, the activation temperature is 350-450° C., and the activation time is 3-6 hours.
[0027] Preferably, the activation temperature of the nickel-based catalyst is 400° C. and the activation time is 5 hours.
[0028] The inventor creatively found through a large number of experiments that by controlling the reaction temperature and the reaction feed, and using the nickel-based catalyst of the present invention, the isopropanol yield is more than 85% and the selectivity is more than 96%. The inventor believes that the possible reason is that the by-products of acetone hydrogenation are mainly isopropyl ether and 5-methyl-2-pentanol, and the molecular diameter of the by-products is greater than that of isopropanol. Therefore, the catalyst carrier with a small pore size is selected to help suppress the side reaction, thereby improving the selectivity. The addition of Zn and nickel will not affect the size of the original pore size of the activated carbon. The larger the mass loading of Zn and nickel, the higher the isopropanol yield, but the selectivity will decline. Therefore, the inventor finds that the mass loading of Zn and nickel must be controlled to be 5-10wt%, and the selectivity can be guaranteed to be more than 96% while improving the yield more than 85%.
[0029] In one embodiment, the S2 gas-liquid separation is specifically: separation of isopropanol and hydrogen, the material enters the gas-liquid separation tank after cooling, the unreacted hydrogen is separated and sent back to the reactor inlet through the compressor for recycling, and the separated liquid enters the separation zone for further separation.
[0030] In one embodiment, the S3 water separation is specifically as follows: the liquid treated in step S2 and diisopropylamine are mixed and then enter the middle of a water separation tower for rectification and separation, and a stream containing isopropanol and components with higher boiling points is extracted from the bottom of the tower.
[0031] Preferably, the water separation tower has a theoretical plate number of 30-70, a mass reflux ratio of 2-10, operates under normal pressure, and a tower top temperature of 50-70°C.
[0032] Furthermore, the water separation tower has 65 theoretical plates, a mass reflux ratio of 5, operates under normal pressure, and a tower top temperature of 55°C.
[0033] In one embodiment, the S4 isopropanol deweighting process is as follows: the logistics from the kettle of the water separation tower enters the isopropanol deweighting tower, and the isopropanol product is extracted from the top of the tower by distillation separation.
[0034] Preferably, the deweighting tower has a pressure of 0.1-1 MPa, a theoretical plate number of 15-25, and a mass reflux ratio of 9-12.
[0035] Further preferably, the deweighting tower has a pressure of 0.5 MPa, a theoretical plate number of 18, and a mass reflux ratio of 10.
[0036] Beneficial effects:
[0037] 1. The present invention controls the reaction temperature and reaction feed and uses the nickel-based catalyst of the present invention, so that the isopropanol yield is above 85% and the selectivity is above 96%.
[0038] 2. The present invention controls the operating temperature, operating pressure, theoretical plate number and mass reflux ratio of the water separation tower and the deweighting tower to prepare isopropanol with a purity of more than 99.5%.
[0039] 3. The method of the present invention is simple to operate, environmentally friendly and has low energy consumption. DETAILED DESCRIPTION
[0040] Example 1
[0041] This embodiment 1 discloses a method for producing isopropanol by hydrogenating acetone, the steps of which are as follows:
[0042] S1 Acetone hydrogenation: Acetone reacts with hydrogen under the action of hydrogenation catalyst to generate materials mainly composed of isopropanol and hydrogen. The acetone hydrogenation temperature is 110℃, the pressure is 2Mpa, and the acetone liquid phase volume space velocity is 0.1h -1 , the catalyst loading was 10 mL.
[0043] In the acetone hydrogenation process, the molar feed ratio of hydrogen to acetone is 1.5:1.
[0044] The hydrogenation catalyst is a nickel-based catalyst.
[0045] The Ni mass loading of the nickel-based catalyst is 5 wt %.
[0046] The nickel-based catalyst is added with an active promoter.
[0047] The active auxiliary agent is Zn.
[0048] The mass loading amount of the active auxiliary agent is 5 wt %.
[0049] The nickel-based catalyst carrier is activated carbon.
[0050] The nickel-based catalyst needs to be activated before use, the activation temperature is 350° C., and the activation time is 6 hours.
[0051] S2 Gas-liquid separation: separation of isopropanol and hydrogen. The material enters the gas-liquid separation tank after cooling. The unreacted hydrogen is separated and sent back to the reactor inlet through the compressor for recycling. The separated liquid enters the separation area for further separation.
[0052] S3 Water Separation: The liquid treated in step S2 is mixed with diisopropylamine and enters the middle of the water separation tower for rectification and separation, and a stream containing isopropanol and components with higher boiling points is extracted from the bottom of the tower.
[0053] The water separation tower has 65 theoretical plates, a mass reflux ratio of 5, operates under normal pressure, and has a tower top temperature of 55°C.
[0054] S4 Isopropyl alcohol de-weighting: The material flow from the kettle of the water separation tower enters the isopropyl alcohol de-weighting tower, and the isopropyl alcohol product is extracted from the top of the tower through distillation separation.
[0055] The deweighting tower has a pressure of 0.5 MPa, a theoretical plate number of 18, and a mass reflux ratio of 10.
[0056] Example 2
[0057] This embodiment 2 discloses a method for producing isopropanol by hydrogenating acetone, the steps of which are as follows:
[0058] S1 Acetone hydrogenation: Acetone reacts with hydrogen under the action of hydrogenation catalyst to generate materials mainly composed of isopropanol and hydrogen. The acetone hydrogenation temperature is 160℃, the pressure is 4Mpa, and the acetone liquid phase volume space velocity is 2h -1 , the catalyst loading was 20 mL.
[0059] In the acetone hydrogenation process, the molar feed ratio of hydrogen to acetone is 4:1.
[0060] The hydrogenation catalyst is a nickel-based catalyst.
[0061] The Ni mass loading of the nickel-based catalyst is 10 wt %.
[0062] The nickel-based catalyst is added with an active promoter.
[0063] The active auxiliary agent is Zn.
[0064] The mass loading amount of the active auxiliary agent is 10 wt %.
[0065] The nickel-based catalyst carrier is activated carbon.
[0066] The nickel-based catalyst needs to be activated before use, the activation temperature is 450° C., and the activation time is 3 hours.
[0067] S2 Gas-liquid separation: separation of isopropanol and hydrogen. The material enters the gas-liquid separation tank after cooling. The unreacted hydrogen is separated and sent back to the reactor inlet through the compressor for recycling. The separated liquid enters the separation area for further separation.
[0068] S3 Water Separation: The liquid treated in step S2 is mixed with diisopropylamine and enters the middle of the water separation tower for rectification and separation, and a stream containing isopropanol and components with higher boiling points is extracted from the bottom of the tower.
[0069] The water separation tower has 65 theoretical plates, a mass reflux ratio of 5, operates under normal pressure, and has a tower top temperature of 55°C.
[0070] S4 Isopropyl alcohol de-weighting: The material flow from the kettle of the water separation tower enters the isopropyl alcohol de-weighting tower, and the isopropyl alcohol product is extracted from the top of the tower through distillation separation.
[0071] The deweighting tower has a pressure of 0.5 MPa, a theoretical plate number of 18, and a mass reflux ratio of 10.
[0072] Example 3
[0073] This embodiment 3 discloses a method for producing isopropanol by hydrogenating acetone, the steps of which are as follows:
[0074] S1 Acetone hydrogenation: Acetone reacts with hydrogen under the action of a hydrogenation catalyst to generate materials mainly composed of isopropanol and hydrogen. The acetone hydrogenation temperature is 120°C, the pressure is 3Mpa, and the acetone liquid phase volume space velocity is 0.5h -1 , the catalyst loading was 15 mL.
[0075] In the acetone hydrogenation process, the molar feed ratio of hydrogen to acetone is 2:1.
[0076] The hydrogenation catalyst is a nickel-based catalyst.
[0077] The Ni mass loading of the nickel-based catalyst is 8 wt %.
[0078] The nickel-based catalyst is added with an active promoter.
[0079] The active auxiliary agent is Zn.
[0080] The mass loading amount of the active auxiliary agent is 8 wt %.
[0081] The nickel-based catalyst carrier is activated carbon.
[0082] The nickel-based catalyst needs to be activated before use, the activation temperature is 400° C., and the activation time is 5 hours.
[0083] S2 Gas-liquid separation: separation of isopropanol and hydrogen. The material enters the gas-liquid separation tank after cooling. The unreacted hydrogen is separated and sent back to the reactor inlet through the compressor for recycling. The separated liquid enters the separation area for further separation.
[0084] S3 Water Separation: The liquid treated in step S2 is mixed with diisopropylamine and enters the middle of the water separation tower for rectification and separation, and a stream containing isopropanol and components with higher boiling points is extracted from the bottom of the tower.
[0085] The water separation tower has 65 theoretical plates, a mass reflux ratio of 5, operates under normal pressure, and has a tower top temperature of 55°C.
[0086] S4 Isopropyl alcohol de-weighting: The material flow from the kettle of the water separation tower enters the isopropyl alcohol de-weighting tower, and the isopropyl alcohol product is extracted from the top of the tower through distillation separation.
[0087] The deweighting tower has a pressure of 0.5 MPa, a theoretical plate number of 18, and a mass reflux ratio of 10.
[0088] Example 4
[0089] The hydrogenation catalyst is a nickel-based catalyst.
[0090] The Ni mass loading of the nickel-based catalyst is 12 wt %.
[0091] The nickel-based catalyst is added with an active promoter.
[0092] The active auxiliary agent is Zn.
[0093] The mass loading amount of the active auxiliary agent is 12 wt %.
[0094] The nickel-based catalyst carrier is activated carbon, and the rest is the same as in Example 3.
[0095] Example 5
[0096] The nickel-based catalyst needs to be activated before use, the activation temperature is 600° C., the activation time is 5 h, and the rest is the same as in Example 3.
[0097] Example 6
[0098] The acetone hydrogenation temperature is 200°C, the pressure is 3 MPa, and the acetone liquid phase volume space velocity is 1 h -1 The catalyst loading amount is 10 mL, and the rest is the same as in Example 3.
[0099] Performance Test:
[0100] After step S1, the conversion rate of acetone, the selectivity of isopropanol, and the purity of the product finally obtained through S4 were tested, and the results are shown in the table below.
[0101] Conversion rate wt% Selectivity wt% Purity wt% Example 1 86 96.2 99.6 Example 2 87 96.8 99.8 Example 3 88 97.9 99.9 Example 4 92 67.9 98.2 Example 5 43 52.1 97.3 Example 6 94 78.2 99.2
Claims
1. A method for producing isopropanol by hydrogenating acetone, characterized in that: Here are the steps: S1 Acetone hydrogenation: Acetone reacts with hydrogen under the action of a hydrogenation catalyst to generate materials mainly composed of isopropanol and hydrogen; the acetone hydrogenation temperature is 120°C, the pressure is 3Mpa, the acetone liquid phase volume space velocity is 0.5h-1, and the catalyst loading is 15mL; In the acetone hydrogenation process, the molar feed ratio of hydrogen to acetone is 2:1; The hydrogenation catalyst is a nickel-based catalyst; The Ni mass loading of the nickel-based catalyst is 8 wt%; The nickel-based catalyst is added with an active promoter; The active auxiliary agent is Zn; The mass loading amount of the active auxiliary agent is 8wt%; The nickel-based catalyst carrier is activated carbon; The nickel-based catalyst needs to be activated before use, the activation temperature is 400°C, and the activation time is 5h; S2 Gas-liquid separation: separation of isopropanol and hydrogen. After cooling, the material enters the gas-liquid separation tank. The unreacted hydrogen is separated and sent back to the reactor inlet through the compressor for recycling. The separated liquid enters the separation zone for further separation. S3 water separation: the liquid treated in step S2 is mixed with diisopropylamine and then enters the middle of the water separation tower for rectification and separation, and a stream containing isopropyl alcohol and components with higher boiling points is extracted from the bottom of the tower; The water separation tower has 65 theoretical plates, a mass reflux ratio of 5, operates at normal pressure, and a tower top temperature of 55°C; S4 Isopropyl alcohol de-weighting: The logistics from the water separation tower kettle enters the isopropyl alcohol de-weighting tower, and the isopropyl alcohol product is extracted from the top of the tower through distillation separation; The deweighting tower has a pressure of 0.5 MPa, a theoretical plate number of 18, and a mass reflux ratio of 10.