A method and apparatus for producing diisobutene by dehydration of tertiary butyl alcohol and applications thereof

Abstract

The application discloses a method and device for preparing high-purity dimerized isobutene from tert-butyl alcohol and application thereof. The method comprises the following steps: 1) mixing an unmodified dry base hydrogen type sulfonic acid resin with a solution containing metal chloride, impregnating, washing, suction filtering and drying to obtain a modified sulfonic acid resin catalyst; 2) performing a dehydration reaction on tert-butyl alcohol under the action of the modified sulfonic acid resin catalyst obtained in the step 1) to obtain isobutene; the isobutene contains tert-butyl alcohol, and a dimerization reaction of the isobutene is performed under the action of the modified sulfonic acid resin catalyst to obtain a dimerization product; 3) separating the dimerization product to obtain isobutene polymer; and performing separation again to obtain dimerized isobutene. The method and device can reduce a process flow and save energy consumption while producing high-purity dimerized isobutene.

Description

Technical Field

[0001] This invention relates to a method, apparatus, and application for producing high-purity diisobutylene, specifically to a method, apparatus, and application for producing diisobutylene from tert-butanol via a dehydration process. Background Technology

[0002] Diisobutylene (2,4,4-trimethyl-1-pentene and 2,4,4-trimethyl-2-pentene) can be used as an intermediate product in detergents and is also an important raw material for the production of various fine chemical products such as octylphenol and amines. It can also be used to produce isononanal via hydroformylation, followed by hydrogenation to prepare isononol, and further used to produce plasticizers and other products.

[0003] The main production methods for isobutylene dimer include sulfuric acid extraction, isobutylene dimerization, and selective C4 polymerization. Sulfuric acid extraction suffers from severe equipment corrosion and environmental pollution. While selective C4 polymerization avoids these problems, at high isobutylene conversion rates (>99%), copolymerization between isobutylene and n-butene is unavoidable, resulting in an oligomer content of approximately 10%-20% in the product, leading to low purity of the isobutylene dimer. For example, CN107652152A uses a phosphonic acid-modified resin as a catalyst for the C4 polymerization reaction. Without the addition of inhibitors, the reaction proceeds through a two-stage process: a fixed-bed reactor and a catalytic distillation column. In the fixed-bed reactor, the isobutylene conversion reaches over 75%, and the isobutylene dimerization selectivity exceeds 98%. In the catalytic distillation column, the total isobutylene conversion reaches over 99.5%, and the isobutylene dimerization selectivity exceeds 98%. However, the copolymerization of n-butene and isobutylene is still unavoidable.

[0004] Dehydration of tert-butanol is another major method for producing high-purity isobutylene besides MTBE cracking. Tert-butanol dehydration mainly employs two processes: fixed-bed distillation and reactive distillation. It has advantages such as simple process flow, few side reactions, easy separation and purification, and high product quality. Therefore, there are also reports of co-producing diisobutylene from tert-butanol dehydration. CN107457001A also uses sulfonic acid resin as a catalyst to couple tert-butanol water with isobutylene dimerization. This saves reactor energy consumption and allows for better control of the reaction temperature, thereby improving the selectivity of diisobutylene. However, it still employs a separation section between tert-butanol and isobutylene, making the reaction process relatively complex. Summary of the Invention

[0005] To address the aforementioned problems in the existing technology, this invention provides a novel method and apparatus for producing diisobutylene by dehydrating tert-butanol. The method of this invention can simplify the process and save energy while producing high-purity diisobutylene.

[0006] The first aspect of this invention provides a method for producing diisobutylene by dehydrating tert-butanol, comprising:

[0007] 1) Unmodified dry-based hydrogen sulfonic acid resin is mixed with a solution containing metal chloride, impregnated, washed, filtered, and dried to obtain a modified sulfonic acid resin catalyst.

[0008] 2) Dehydrate tert-butanol under the action of the modified sulfonic acid resin catalyst obtained in step 1) to obtain isobutylene; the isobutylene contains tert-butanol, and isobutylene dimerizes under the action of the modified sulfonic acid resin catalyst to obtain dimer product.

[0009] 3) The dimer product is separated to obtain isobutylene polymer; it is separated again to obtain dimer isobutylene.

[0010] According to some embodiments of the method described in this invention, the preparation method of the unmodified dry hydrogen sulfonic acid resin includes: washing a wet-based hydrogen sulfonic acid resin and then vacuum drying it to obtain an unmodified dry-based hydrogen sulfonic acid resin. In this invention, "wet-based" refers to resin without dried moisture. "Dry-based" refers to resin with moisture removed. Preferably, anhydrous ethanol, anhydrous methanol, or acetone is used for washing.

[0011] According to some embodiments of the method of the present invention, the hydrogen sulfonic acid resin is selected from at least one of D006 resin, D005 resin, Amberlyst-15 resin, Amberlyst-35 resin, nkc-9 resin, and amberlyst-45 resin; preferably D006 resin and / or Amberlyst-15 resin.

[0012] According to some embodiments of the method described in this invention, the metal chloride is selected from at least one of ferric chloride, zirconium oxychloride, aluminum trichloride, zinc chloride, and magnesium chloride; preferably ferric chloride and / or zirconium oxychloride; more preferably zirconium oxychloride.

[0013] According to some embodiments of the method of the present invention, in the solution containing the metal chloride, the concentration of the metal chloride is 1-10% by weight, preferably 4-7% by weight.

[0014] According to some embodiments of the method of the present invention, the method of making the isobutylene contain tert-butanol includes: adjusting the operating parameters of a catalytic distillation column.

[0015] According to some embodiments of the method described in this invention, the operating parameters of the catalytic distillation column include: a tert-butanol feed mass hourly space velocity of 1.8-2.4 h⁻¹. -1The height of the reaction section of the catalytic distillation column is 0.8-1.2m; the height of the catalytic rectification section is 0.4-0.6m; and the height of the stripping section is 1.5-2m.

[0016] According to some embodiments of the method described in this invention, the isobutylene contains tert-butanol, wherein the content of tert-butanol is controlled at 3-6% by weight, preferably 4-5% by weight, with the remainder being isobutylene, and the product is anhydrous. That is, the content of tert-butanol in the product at the top of the catalytic distillation column is controlled at 3-6% by weight, preferably 4-5% by weight, with the remainder being isobutylene, and the product is anhydrous.

[0017] According to some embodiments of the method described in this invention, the conditions for the isobutylene dimerization reaction include: a temperature of 25-35°C, a pressure of 0.4-0.8 MPa, and an isobutylene feed space velocity of 2.5-4 h⁻¹. -1 .

[0018] According to some embodiments of the method of the present invention, the dimer product is separated to obtain tert-butanol and unreacted isobutylene, and preferably the tert-butanol and unreacted isobutylene are returned to the catalytic distillation column for recycling.

[0019] According to some embodiments of the method described in this invention, the soaking time can be 4-12 hours.

[0020] According to some embodiments of the method described in this invention, washing can be performed using deionized water.

[0021] According to some embodiments of the method described in this invention, filtration can be a conventional operation in the art, and will not be described in detail here.

[0022] According to some embodiments of the method described in this invention, the drying temperature can be 100-120°C and the drying time can be 10-14 hours.

[0023] According to some specific embodiments of the method described in this invention, the method for producing diisobutylene by dehydration of tert-butanol may include, but is not limited to:

[0024] 1) Weigh a certain amount of wet-based hydrogen sulfonic acid resin, place it in an Erlenmeyer flask, and wash it three times with anhydrous ethanol. After washing, dry it under vacuum at 80°C to obtain unmodified dry-based hydrogen sulfonic acid resin.

[0025] The dried hydrogen form sulfonic acid resin was placed in a three-necked flask, and then a solution of metal chloride was added. The mixture was impregnated at room temperature for 4-12 hours. After washing with deionized water, the mixture was filtered, dried in a vacuum oven for 12 hours, and then cooled to room temperature in a desiccator to obtain the modified sulfonic acid resin catalyst.

[0026] 2) The modified sulfonic acid resin catalyst described in step 1) is packed into the reaction section of the catalytic distillation column. Fresh and recovered tert-butanol is introduced into the reaction section and undergoes a dehydration reaction under the action of the catalyst. By selecting an appropriate number of trays and feed position, and controlling the tert-butanol feed rate, a certain tert-butanol conversion rate is controlled so that the isobutylene collected from the top of the column contains a small amount of tert-butanol (the content of tert-butanol is controlled at 3-6% by weight, preferably 4-5% by weight); water is collected from the bottom of the column.

[0027] 3) The isobutylene containing tert-butanol from the top of the catalytic distillation column in step 2) is fed into the polymerization reactor, which is also filled with the modified sulfonic acid resin catalyst described in step 1), to carry out the isobutylene dimerization reaction, which can achieve high selectivity for dimerized isobutylene.

[0028] 4) After separation, the dimerized product is recycled back to the catalytic distillation column with tert-butanol and unreacted isobutylene. The isobutylene polymer is obtained from the bottom of the separation column, and after further separation, the dimerized isobutylene product is obtained.

[0029] A second aspect of the present invention provides an apparatus for producing diisobutylene by dehydrating tert-butanol, comprising: a catalytic distillation column, a polymerization reactor, a first separation column, and a second separation column connected sequentially by pipelines, wherein...

[0030] The catalytic distillation column is used for the dehydration reaction of tert-butanol under the action of a modified sulfonic acid resin catalyst to obtain isobutylene; by adjusting the operating parameters of the catalytic distillation column, the isobutylene contains tert-butanol, and the top product and bottom product of the catalytic distillation column are obtained.

[0031] The polymerization reactor is used to carry out isobutylene dimerization reaction of the top product of the catalytic distillation column under the action of modified sulfonic acid resin catalyst to obtain dimer product;

[0032] The first separation tower is used to separate the dimer products, and isobutylene polymer is obtained at the bottom of the first separation tower;

[0033] The second separation tower is used to separate isobutylene polymer to obtain dimer isobutylene.

[0034] According to some embodiments of the apparatus described in this invention, the operating parameters of the catalytic distillation column include: a tert-butanol feed mass hourly space velocity of 1.8-2.4 h⁻¹. -1 The height of the reaction section of the catalytic distillation column is 0.8-1.2m; the height of the catalytic rectification section is 0.4-0.6m; and the height of the stripping section is 1.5-2m.

[0035] According to some embodiments of the apparatus of the present invention, the isobutylene contains tert-butanol, wherein the content of tert-butanol is controlled at 3-6% by weight, preferably 4-5% by weight, with the remainder being isobutylene, and the product is anhydrous. That is, the content of tert-butanol in the product at the top of the catalytic distillation column is controlled at 3-6% by weight, preferably 4-5% by weight, with the remainder being isobutylene, and the product is anhydrous.

[0036] According to some embodiments of the apparatus of the present invention, the first separation column is used to separate the dimerization product, and tert-butanol and unreacted isobutylene are obtained at the top of the first separation column. Preferably, the tert-butanol and unreacted isobutylene are returned to the catalytic distillation column for recycling.

[0037] According to some embodiments of the apparatus of the present invention, the preparation method of the modified sulfonic acid resin catalyst includes: washing wet-based hydrogen sulfonic acid resin with anhydrous ethanol, and then vacuum drying to obtain unmodified dry-based hydrogen sulfonic acid resin; mixing the unmodified dry-based hydrogen sulfonic acid resin with a solution containing metal chloride, impregnating, washing, filtering, and drying to obtain the modified sulfonic acid resin catalyst.

[0038] The third aspect of the present invention provides the application of the above-described method and apparatus in the production of diisobutylene.

[0039] The beneficial effects of this invention are:

[0040] (1) By using the method of the present invention, since the acidity of the catalyst is adjusted and the raw material contains a small amount of tert-butanol as an inhibitor, under preferred conditions, the selectivity of dimer isobutylene in the polymerization reaction can reach more than 95% and the isobutylene conversion rate is greater than 90%.

[0041] (2) The method of the present invention can generate diisobutylene with high selectivity using tert-butanol as raw material. While simplifying the isobutylene separation process, it makes full use of the effect of a small amount of tert-butanol as an inhibitor, thereby improving the selectivity of diisobutylene. Detailed Implementation

[0042] To make the present invention easier to understand, the present invention will be described in detail below with reference to embodiments. These embodiments are for illustrative purposes only and are not limited to the scope of application of the present invention.

[0043] The testing method and equipment used in this invention are as follows:

[0044] (1)

[0045] (2)

[0046] (3)

[0047] (4) The instrument used for product content determination was a gas chromatograph, model 7890A, manufactured by Agilent.

[0048]

Example 1

[0049] 1. Catalyst Preparation

[0050] Measure 100 mL of wet-based hydrogen sulfonic acid resin (D006 resin), place it in an Erlenmeyer flask, and wash it three times with anhydrous ethanol. After washing, dry it under vacuum at 80°C to obtain unmodified dry-based hydrogen sulfonic acid resin.

[0051] The dried, unmodified dry-based hydrogen sulfonic acid resin was placed in a three-necked flask, and then a 10% by weight aqueous solution of zirconium oxychloride was added. The mixture was impregnated at room temperature for 8 hours, washed with deionized water, filtered, dried in a vacuum oven at 120°C for 12 hours, and then cooled to room temperature in a desiccator to obtain the chlorine-modified sulfonic acid resin catalyst.

[0052] 2. Reaction process

[0053] The modified sulfonic acid resin catalyst was packed into the reaction section of the catalytic distillation column and the polymerization reactor. The tert-butanol feedstock, after preheating, entered the middle of the catalyst bed in the catalytic distillation column for dehydration. The tert-butanol feed space velocity was 2.0 h⁻¹. -1 The pressure of the catalytic distillation column is 0.6 MPa. After the reaction, the conversion rate of tert-butanol is 90.2%. By adjusting the reflux ratio of the column to 1.6, the tert-butanol content in the isobutylene at the top of the column is 5.1%, and the remainder is isobutylene, which does not contain water. The water by-product generated by the reaction is separated at the bottom of the column.

[0054] The isobutylene (containing 5.1% tert-butanol) from the top of the catalytic distillation column then enters the polymerization reactor for isobutylene dimerization. The reaction temperature is 30°C, the reaction pressure is 0.6 MPa, and the isobutylene feed space velocity is 3.0 h⁻¹. -1 After passing through the polymerization reactor, the isobutylene conversion rate was 90.1%, and the selectivity of dimer isobutylene was 98.5%. After separation in the first separation tower, the tert-butanol and isobutylene at the top of the first separation tower were returned to the catalytic distillation tower for recycling, while the isobutylene polymer obtained at the bottom of the first separation tower was further separated in the second separation tower to obtain dimer isobutylene product and the by-product trimer isobutylene.

[0055]

Example 2

[0056] The reflux ratio of the tert-butanol dehydration catalytic distillation column was 1.8, and the other conditions were the same as in Example 1. After the reaction, the tert-butanol conversion rate was 90.5%, and the isobutylene product at the top of the column contained 4% tert-butanol, with the remainder being isobutylene, which was anhydrous. After passing through the polymerization reactor, the isobutylene conversion rate was 92.3%, and the selectivity for dimerized isobutylene was 91.4%.

[0057]

Example 3

[0058] The reflux ratio of the tert-butanol dehydration catalytic distillation column was 2.1, and the other conditions were the same as in Example 1. After the reaction, the tert-butanol conversion rate was 89.6%, and the isobutylene product at the top of the column contained 3% tert-butanol, with the remainder being isobutylene, which was anhydrous. After passing through the polymerization reactor, the isobutylene conversion rate was 93.5%, and the selectivity for dimerized isobutylene was 90.1%.

[0059]

Example 4

[0060] The reflux ratio of the tert-butanol dehydration catalytic distillation column was 1.4, and the other conditions were the same as in Example 1. After the reaction, the tert-butanol conversion rate was 89.8%, and the isobutylene product at the top of the column contained 6% tert-butanol, with the remainder being isobutylene, which was anhydrous. After passing through the polymerization reactor, the isobutylene conversion rate was 88.9%, and the selectivity for dimerized isobutylene was 98.9%.

[0061]

Example 5

[0062] The reflux ratio of the tert-butanol dehydration catalytic distillation column was 3.5, and the other conditions were the same as in Example 1. After the reaction, the tert-butanol conversion rate was 97.1%, and the isobutylene product at the top of the column contained 1.8% tert-butanol, with the remainder being isobutylene, which was anhydrous. After passing through the polymerization reactor, the isobutylene conversion rate was 98.7%, and the selectivity for dimerized isobutylene was 75.5%.

[0063]

Example 6

[0064] The reflux ratio of the tert-butanol dehydration catalytic distillation column was 1.2, and the other conditions were the same as in Example 1. After the reaction, the tert-butanol conversion rate was 84.7%, and the isobutylene product at the top of the column contained 8% tert-butanol, with the remainder being isobutylene, which was anhydrous. After passing through the polymerization reactor, the isobutylene conversion rate was 78.2%, and the selectivity for dimerized isobutylene was 99.0%.

[0065]

Example 7

[0066] The wet-based hydrogen sulfonic acid resin in Example 1 was replaced with Amberlyst-15 resin, while the other conditions remained the same as in Example 1. After passing through the polymerization reactor, the isobutylene conversion rate was 92.6%, and the diisobutylene selectivity was 85.7%.

[0067]

Example 8

[0068] In Example 1, the metal chloride was replaced with zirconium oxychloride at a concentration of 4% by weight instead of 10% by weight, while the other conditions remained the same as in Example 1. After passing through the polymerization reactor, the isobutylene conversion rate was 94.1%, and the diisobutylene selectivity was 86.5%.

[0069]

Example 9

[0070] In Example 1, the metal chloride was replaced with ferric chloride instead of zirconium oxychloride, while the other conditions remained the same as in Example 1. After passing through the polymerization reactor, the isobutylene conversion rate was 82.6%, and the diisobutylene selectivity was 97.4%.

[0071] Comparative Example 1

[0072] Unmodified dry-based hydrogen sulfonic acid resin was used for the isobutylene dimerization reaction (the polymerization reactor used unmodified dry-based hydrogen sulfonic acid resin), and the other conditions were the same as in Example 1. After passing through the polymerization reactor, the isobutylene conversion rate was 96.5%, and the isobutylene dimerization selectivity was 75.2%.

[0073] Comparative Example 2

[0074] Unmodified dry-based hydrogen sulfonic acid resin was used for the dehydration reaction (unmodified dry-based hydrogen sulfonic acid resin was used in the catalytic distillation column), and other conditions were the same as in Example 1. After passing through the polymerization reactor, the isobutylene conversion rate was 95.1%, and the diisobutylene selectivity was 86.3%.

[0075] The results of Examples 1-9 and Comparative Examples 1-2 demonstrate that the method of the present invention exhibits high isobutylene conversion and diisobutylene selectivity. Especially in the preferred embodiment of the present invention, the effect is significantly superior to that of the comparative examples.

[0076] The above description is merely a preferred embodiment of the present invention. It should be noted that, for those skilled in the art, based on the technical teachings provided by the present invention and as common knowledge in the field, other equivalent modifications and improvements can be made, and these should also be considered within the scope of protection of the present invention.

Claims

1. A method for producing diisobutylene by dehydrating tert-butanol, comprising: 1) Unmodified dry-based hydrogen sulfonic acid resin is mixed with a solution containing metal chloride, impregnated, washed, filtered, and dried to obtain a modified sulfonic acid resin catalyst. 2) Dehydrate tert-butanol under the action of the modified sulfonic acid resin catalyst obtained in step 1) to obtain isobutylene; such that the isobutylene contains tert-butanol, and undergoes isobutylene dimerization under the action of the modified sulfonic acid resin catalyst to obtain dimer product. 3) The dimer product is separated to obtain isobutylene polymer; it is separated again to obtain isobutylene dimer; The isobutylene contains tert-butanol, wherein the content of tert-butanol is controlled at 3-6% by weight, and the remainder is isobutylene, and it contains no water.

2. The method according to claim 1, characterized in that, The preparation method of the unmodified dry-based hydrogen sulfonic acid resin includes: washing the wet-based hydrogen sulfonic acid resin and then vacuum drying it to obtain the unmodified dry-based hydrogen sulfonic acid resin.

3. The method according to claim 2, characterized in that, Wash with anhydrous ethanol, anhydrous methanol, or acetone.

4. The method according to any one of claims 1-3, characterized in that, The hydrogen sulfonic acid resin is selected from at least one of D006 resin, D005 resin, Amberlyst-15 resin, Amberlyst-35 resin, nkc-9 resin, and amberlyst-45 resin.

5. The method according to any one of claims 1-3, characterized in that, The metal chloride is selected from at least one of ferric chloride, zirconium oxychloride, aluminum trichloride, zinc chloride, and magnesium chloride; and / or, In solutions containing metal chlorides, the concentration of the metal chloride is 1-10% by weight.

6. The method according to claim 5, characterized in that, The metal chloride is selected from ferric chloride and / or zirconium oxychloride; and / or, In solutions containing metal chlorides, the concentration of the metal chlorides is 4-7% by weight.

7. The method according to any one of claims 1-3, characterized in that, Methods for making the isobutylene contain tert-butanol include: adjusting the operating parameters of a catalytic distillation column; and / or, The isobutylene contains tert-butanol, wherein the content of tert-butanol is controlled at 4-5% by weight, and the remainder is isobutylene, and it contains no water.

8. The method according to claim 7, characterized in that, The operating parameters of the catalytic distillation column include: a tert-butanol feed mass hourly space velocity (MHSV) of 1.8-2.4 h⁻¹. -1 The height of the reaction section of the catalytic distillation column is 0.8-1.2m; the height of the catalytic rectification section is 0.4-0.6m; and the height of the stripping section is 1.5-2m.

9. The method according to any one of claims 1-3, characterized in that, The conditions for the isobutylene dimerization reaction include: a temperature of 25-35℃, a pressure of 0.4-0.8 MPa, and an isobutylene feed space velocity of 2.5-4 h⁻¹. -1 .

10. The method according to any one of claims 1-3, characterized in that, Separation of the dimer product yielded tert-butanol and unreacted isobutene.

11. The method according to claim 10, characterized in that, The separated tert-butanol and unreacted isobutene are returned to the catalytic distillation column for recycling.

12. The use of the method according to any one of claims 1-11 in the production of diisobutylene.