Reaction device for synthesizing C8-13 alcohol benzene polyacid ester by continuous method

Abstract

The utility model relates to a reaction device for synthesizing C8-13 alcohol benzene polyacid ester by a continuous method in the field of chemical equipment. A tower body of the reaction device consists of a catalytic reaction section, a rectification dealcoholization section and a reflux section from bottom to top, a feed port and a discharge port are formed in the side wall of the catalytic reaction section, a weight removal port is formed in the bottom of the catalytic reaction section, a gas guide rising pipe is arranged in the catalytic reaction section, a gas inlet is formed below the gas guide rising pipe, and a catalyst loading tank is reserved between the side wall of the catalytic reaction section and the guide rising pipe; a plurality of tower plates are arranged in the rectification dealcoholization section; the tower plates obliquely extend inwards and downwards from the side wall of the rectification dealcoholization section; upper and lower adjacent layers of tower plates are arranged in a staggered manner; a light component removal opening is formed in the side surface of the rectification and dealcoholization section; a liquid distributor is arranged at the top in the reflux section, and a gas phase outlet is formed in the side surface of the upper part of the reflux section and is connected to the liquid distributor through a condensation reflux device and a reflux control valve. The device can be used for continuously synthesizing C8-13 alcohol benzene polyacid ester, and is short in process flow and good in product quality.

Description

Technical Field

[0001] The utility model relates to chemical equipment, in particular to an esterification reactor for C8-13 alcohol benzene polyacid esters. Background Art

[0002] C8-13 alcohol benzene polyacid esters mainly include o- / iso- / terephthalate esters, trimellitic acid esters and pyromellitic acid esters. The raw materials are C8-13 alcohol and benzene polyacid or anhydride. C8-13 alcohol includes octanol (C8 alcohol), nonanol (C9 alcohol), octanol (C810 alcohol), decanol (C10 alcohol), carbon dodecanol (C12 alcohol), carbon tridecanol (C13 alcohol), etc. Benzene polyacid or anhydride refers to dibasic and higher benzoic acid or anhydride (benzene polyacid can be divided into benzene dibasic acid or anhydride, benzene tribasic acid or anhydride, benzene tetrabasic acid or anhydride, etc.).

[0003] Ortho / iso / terephthalate esters are plasticizers and additives that can achieve modification effects. They are mainly used in polyvinyl chloride materials to make hard plastics become elastic plastics, acting as plasticizers. High molecular weight ester compounds not only have good stability and low volatility, but also have the characteristics of high viscosity, making them the preferred material for viscosity regulators and widely used in the fields of lubricants, rubber and plastics.

[0004] Trimellitate, referred to as TMT, has a molecular formula of C6H3(COOR)3, where R is an alkyl group. Industrial products are usually colorless or yellow transparent liquids. Trimellitate is obtained by esterification of trimellitic anhydride and C8-13 fatty alcohol under the action of a catalyst, followed by alkali washing, water washing, dealcoholization and purification, and finally filtration.

[0005] Trimellitate esters have the following excellent properties: viscosity gradient distribution, high flash point, low pour point, good low-temperature fluidity, wider operating temperature range, small evaporation loss, good high-temperature stability, good oxidation stability, less carbon residue, excellent lubrication performance, extremely low toxicity, environmental protection, and good biodegradability. The disadvantage is that the hydrolysis resistance is poor and the compatibility with rubber parts is average.

[0006] Application fields of trimellitic acid esters: trimellitic acid esters have excellent high and low temperature performance, low high temperature evaporation, low coking amount, and good compatibility with various additives. It is an ideal base oil for synthetic high temperature chain oil, synthetic high viscosity air compressor oil and high temperature grease. When used to prepare high viscosity and high temperature chain oil, the amount of thickener can be reduced, thereby improving the high temperature performance of the chain oil; when used to prepare synthetic high viscosity air compressor oil, thickener can be used to increase the viscosity. It is mainly used for automotive lubricants and industrial lubricants. For example, the content of various uses: high temperature chain oil 98%; air compressor oil 98%; high temperature grease 10-90%; industrial gear oil 98%; metalworking fluid 5-15%.

[0007] Pyromellitic acid esters can be obtained by direct esterification of pyromellitic acid or pyromellitic acid dianhydride with alcohol. However, it is generally a mixture of monobasic, dibasic, tribasic and tetrabasic esters. If the alcohol is excessive and the esterification conditions are strengthened, the polybasic esters are more. This mixed ester or the separated monoester can be used as a plasticizer. R1, R2, R3 and R4 of tetrabasic pyromellitic acid ester can be the same or different groups, which are alkyl, alkenyl, cycloalkyl, aromatic, preferably butyl and octyl. Pyromellitic acid esters of various structures have been tried in medical plastic products and achieved good results.

[0008] The continuous process of trioctyl trimellitate mainly includes the processes of feeding and dissolving, esterification, alkali washing and water washing, dealcoholization, adsorption filtration, wastewater treatment, etc., and finally the finished product is obtained. The process has many advantages such as clean and environmentally friendly, pollution-free, strong catalytic performance, and high product yield. In the esterification process, in order to make the reaction equilibrium proceed in the positive direction, the actual production adopts measures such as adding excessive isooctyl alcohol and timely removing the reaction product water to improve the conversion rate of partial anhydride. After the alkali washing and water washing process, the unreacted monoester and diester are removed and the catalyst is hydrolyzed; then enter the dealcoholization process, flash evaporation is used to remove most of the isooctyl alcohol; then the product is further purified by steam stripping in the dealcoholization kettle, and finally the product is obtained by adsorption filtration. In the whole process, the water washing and dealcoholization processes are also key. The reacted materials enter the dealcoholization kettle after the alkali washing and water separation, and the bottom discharge of the dealcoholization kettle ultimately determines the quality specifications of the product.

[0009] The synthesis of benzoate chemicals is mainly focused on the study of esterification reactions. For example, the invention of CN106423219B relates to trimellitic acid esters, and in particular to a method for producing trimellitic acid esters using solid acid with activated clay as a carrier as a catalyst. The invention first uses Lewis acid as an active component to impregnate activated clay to prepare solid acid with activated clay as a carrier, and then adds the solid acid with activated clay as a carrier as a catalyst to the reaction of trimellitic acid esters, and then separates and purifies the products to finally obtain trimellitic acid esters. Compared with the prior art, the advantages and positive effects of the invention are that the invention provides a solid acid with activated clay as a carrier to replace concentrated sulfuric acid as a catalyst in the synthesis process of trimellitic acid esters, thereby avoiding the adverse consequences of concentrated sulfuric acid as a catalyst. At the same time, by improving the traditional processing method of trimellitic acid esters, the obtained trimellitic acid esters have a high yield and good quality, which is suitable for large-scale promotion and use.

[0010] The invention of CN110156599A relates to a method for preparing trimellitic acid ester, comprising: in the presence of a catalyst, allowing trimellitic anhydride and / or trimellitic acid to contact and react with a monohydric fatty alcohol, while removing the water generated by the reaction; the catalyst is a bulk catalyst containing silicon, tin and oxygen and containing Sn-O-Si bonds. The method of the invention has high conversion rate and selectivity, and the catalyst is easy to separate from the reaction product and can be reused many times.

[0011] CN114471410A adopts a reaction device that simultaneously completes the esterification and polycondensation of phthalates, namely, an intermittent esterification kettle. Patent CN111960943A describes a semi-continuous process for producing dioctyl terephthalate, which first performs an intermittent esterification reaction, and then continuously neutralizes, washes, de-alcoholizes, strips, decolorizes and filters the esterified mixture to obtain dioctyl terephthalate.

[0012] The intermittent / semi-continuous synthesis process currently used in industry mainly has the following problems:

[0013] (1) The control of the intermittent synthesis process is relatively complex, including multiple control variables such as temperature and liquid level, and strict requirements on the synthesis conditions. The esterification liquid has poor mixing uniformity and the catalytic reaction is not sufficient.

[0014] (2) The intermittent synthesis cycle is long, the energy consumption is high, and the equipment utilization efficiency is low.

[0015] (3) The intermittent method is only suitable for small-scale synthesis and the product stability is low.

[0016] (4) The reaction of benzene polyacid esters of mixed alcohols is difficult and requires high equipment.

[0017] (5) C8-13 alcohol benzene polyacid ester has poor fluidity and high production cost.

[0018] (6) Semi-continuous synthesis. However, the continuous synthesis process involved is relatively complicated, including multiple processes such as esterification, dealcoholization, neutralization and water washing, stripping, adsorption filtration, and wastewater treatment. It uses a large number of equipment, has low equipment utilization, and consumes a lot of energy. Utility Model Content

[0019] The purpose of the utility model is to provide a reaction device for continuously synthesizing C8-13 alcohol benzene polyacid esters, so that it can overcome the defects of the prior art, so that in the reaction process, not only can the esterification liquid be mixed more evenly, but also can effectively avoid the problem of insufficient catalytic reaction caused by material fluidity problems, thereby realizing continuous synthesis of C8-13 alcohol benzene polyacid esters, shortening the process flow and improving product quality.

[0020] The purpose of the utility model is achieved as follows: a reaction device for synthesizing C8-13 alcohol benzene polyacid ester by continuous method, comprising a tower body of a rotary structure arranged vertically, the tower body being composed of a catalytic reaction section, a distillation dealcoholization section and a reflux section from bottom to top; a feed inlet is arranged at the upper part of the side wall of the catalytic reaction section, a discharge outlet is arranged at the lower part of the side wall of the catalytic reaction section, a de-heavy port is arranged at the bottom of the catalytic reaction section, a gas riser is arranged in the catalytic reaction section, an air inlet is arranged below the gas riser, and a catalyst loading pool is left between the side wall of the catalytic reaction section and the riser; a plurality of tower plates are arranged in the distillation dealcoholization section; the tower plates extend inwardly and downwardly from the side wall of the distillation dealcoholization section; the tower plates of the upper and lower adjacent layers are arranged in an alternating manner, and a de-light port is arranged on the side of the distillation dealcoholization section; a liquid distributor is arranged at the top of the reflux section, a gas phase outlet is arranged on the upper side of the reflux section, and the gas phase outlet is connected to the liquid distributor through a condensation reflux device and a reflux control valve arranged outside the tower body.

[0021] The device is used for continuously synthesizing C8-13 alcohol benzene polyacid esters, which uses benzene polyacid or anhydride and C8-13 alcohol as raw materials. The esterification reaction process is as follows: C8-13 alcohol and benzene polyacid or anhydride uniformly mixed in proportion are injected into the upper end of the catalytic reaction section through the feed port. After the materials fill the catalytic reaction section, air is introduced through the air inlet and the temperature is increased for esterification. After the raw materials boil in the kettle, the reflux control valve is opened for full reflux. The light components are refluxed to the liquid distributor and sprayed onto the tower plate. After the reaction is stable, the rising light components are vaporized and discharged through the light removal port, and part of them continue to reflux from the gas phase outlet after condensation, so as to achieve efficient separation and recovery of C8-C13 alcohol. The esterified liquid is continuously discharged through the discharge port and then enriched and processed.

[0022] Compared with the prior art, the beneficial effects of the utility model are:

[0023] 1. The gas riser promotes the circulation and tumbling of gas and liquid. The gas and liquid bubble up and fall on the upper part of the catalyst. The material is fully in contact with the catalyst, making the reaction uniform and efficient. It can also effectively avoid the problem of insufficient catalytic reaction due to material fluidity problems.

[0024] 2. The liquid is sprayed onto the tower plate and volatilized again by heating, which can promote the phase separation of light components and heavy components, thereby achieving the purpose of efficient separation and recovery of C8-C13 alcohols.

[0025] 3. Compared with the existing intermittent or semi-continuous processes at home and abroad, this process has improved the degree of automation, shortened the process flow, and improved product quality.

[0026] Furthermore, the angle between the tower plate and the side wall of the distillation dealcoholization section is 60° to 75°.

[0027] Furthermore, the distillation dealcoholization section includes at least two units, and the light removal port is arranged on the side of each unit to facilitate graded recovery.

[0028] Furthermore, the tower plate is provided with a plurality of through-flow holes, which makes gas-liquid separation more convenient.

[0029] Furthermore, the air inlet is connected to the lower part of the gas riser via an air distribution pipe.

[0030] Furthermore, the catalyst loading pool is loaded with spherical catalysts. This structure allows certain porosity between the catalysts, and the flow resistance to the reaction materials is relatively small.

[0031] In order to further facilitate the circulation of materials, a liquid convection cavity is left below the catalyst loading pool.

[0032] Furthermore, a heating jacket is provided on the periphery of the catalytic reaction section to facilitate heating of materials by heat-conducting oil. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the structure of the utility model.

[0034] In the figure, 1 is a liquid distributor; 2 is a distillation unit; 3 is a tower plate; 4 is a catalyst loading pool; 5 is a gas riser; 6 is a condensation reflux device; 7 is a reflux control valve; 8 is a liquid convection cavity; 9 is a gas distribution pipe; D1 is a gas phase outlet; D2 and D3 are light removal outlets; D4 is a heavy removal outlet; M1 is a feed inlet; M2 is a discharge outlet; and H1 is an air inlet. DETAILED DESCRIPTION

[0035] like Figure 1 As shown, a reaction device for synthesizing C8-13 alcohol benzene polyacid ester by continuous method comprises a vertically arranged rotating tower body, which is respectively composed of a catalytic reaction section, a distillation dealcoholization section and a reflux section from bottom to top; a feed inlet M1 is provided at the upper part of the side wall of the catalytic reaction section, a discharge outlet M2 is provided at the lower part of the side wall of the catalytic reaction section, a de-heavy port D4 is provided at the bottom of the catalytic reaction section, a gas riser 5 is provided in the catalytic reaction section, a gas inlet H1 is provided below the gas riser 5, and a catalyst loading pool 4 is left between the side wall of the catalytic reaction section and the riser; a plurality of trays 3 are provided in the distillation dealcoholization section; the trays 3 extend inwardly and downwardly from the side wall of the distillation dealcoholization section; trays 3 of upper and lower adjacent layers are arranged alternately, and a de-heavy port is provided on the side of the distillation dealcoholization section; a liquid distributor 1 is provided at the top of the reflux section, a gas phase outlet D1 is provided on the upper side of the reflux section, and the gas phase outlet D1 is connected to the liquid distributor 1 via a condensation reflux device 6 and a reflux control valve 7 provided outside the tower body.

[0036] Furthermore, the angle between the tower plate 3 and the side wall of the distillation dealcoholization section is 60° to 75°.

[0037] Furthermore, the distillation dealcoholization section includes two distillation units 2, and the light removal port is arranged on the side of each distillation unit 2, such as the light removal port D2 and the light removal port D3 in the figure, so as to facilitate graded recovery.

[0038] Furthermore, a plurality of through holes are provided on the tower plate 3, which makes it easier to separate gas and liquid.

[0039] Furthermore, the air inlet H1 is connected to the lower part of the gas riser 5 via the air distribution pipe 9 .

[0040] Furthermore, spherical catalysts are loaded in the catalyst loading pool 4. This structure allows certain porosity between the catalysts, and the flow resistance to the reaction materials is relatively small.

[0041] In order to further facilitate the circulation of materials, a liquid convection cavity 8 is left below the catalyst loading pool 4 .

[0042] Furthermore, a heating jacket is provided on the periphery of the catalytic reaction section to facilitate heating of the material by heat-conducting oil.

[0043] The device is used for continuous synthesis of C8-13 alcohol benzene polyacid esters, which uses benzene polyacid or anhydride and C8-13 alcohol as raw materials. The esterification process is as follows: C8-13 alcohol and benzene polyacid or anhydride uniformly mixed in proportion are pumped into the upper end of the catalytic reaction section through the feed port M1. After the materials fill the catalytic reaction section, air is introduced through the air inlet H1 and the temperature is raised for esterification. After the raw materials boil in the kettle, the reflux control valve 7 is opened for full reflux. The light components are refluxed to the liquid distributor 1 and sprayed onto the tower plate 3. After the reaction is stable, the rising light components are vaporized and discharged through the light removal ports D2 and D3. Part of them continue to reflux from the gas phase outlet D1 after condensation, so as to achieve efficient separation and recovery of C8-C13 alcohol. The esterified liquid is continuously discharged through the discharge port M2 and then enriched and processed. For various different reaction materials, the process parameters are as follows:

[0044] Table 1 Esterification reaction process parameters

[0045]

[0046]

[0047] Table 2 Esterification data results

[0048]

[0049] The above results show that the device can be used for the continuous synthesis of C8-13 alcohol benzene polyacid esters.

[0050] The present utility model is not limited to the above-mentioned embodiments. On the basis of the technical solution disclosed in the present utility model, technicians in this field can make some substitutions and deformations to some technical features therein according to the disclosed technical content without creative labor, and these substitutions and deformations are all within the protection scope of the present utility model.

Claims

1. A reaction device for continuously synthesizing C8-13 alcohol benzene polyacid esters, comprising a vertically arranged rotary tower body, wherein the tower body is composed of a catalytic reaction section, a distillation dealcoholization section and a reflux section from bottom to top; characterized in that: The catalytic reaction section has a feed inlet at the upper part of the side wall, a discharge outlet at the lower part of the side wall, a deweighting port at the bottom of the catalytic reaction section, a gas riser in the catalytic reaction section, an air inlet below the gas riser, and a catalyst loading pool between the side wall of the catalytic reaction section and the riser; The distillation dealcoholization section is provided with a plurality of trays; the trays extend inwardly and downwardly from the side wall of the distillation dealcoholization section; trays of upper and lower adjacent layers are arranged alternately, and a light removal port is provided on the side of the distillation dealcoholization section; A liquid distributor is arranged at the top of the reflux section, a gas phase outlet is arranged on the upper side of the reflux section, and the gas phase outlet is connected to the liquid distributor through a condensation reflux device and a reflux control valve arranged outside the tower body.

2. The reaction device for synthesizing C8-13 alcohol benzene polyacid ester by continuous method according to claim 1, characterized in that: The angle between the tower plate and the side wall of the distillation dealcoholization section is 60° to 75°.

3. The reaction device for synthesizing C8-13 alcohol benzene polyacid ester by continuous method according to claim 1, characterized in that: The distillation dealcoholization section includes at least two units, and the light removal port is arranged on the side of each unit.

4. The reaction device for synthesizing C8-13 alcohol benzene polyacid ester by continuous method according to any one of claims 1 to 3, characterized in that: A plurality of through-flow holes are arranged on the tower plate.

5. The reaction device for synthesizing C8-13 alcohol benzene polyacid ester by continuous method according to any one of claims 1 to 3, characterized in that: The air inlet is connected to the lower part of the gas riser via a gas distribution pipe.

6. The reaction device for continuously synthesizing C8-13 alcohol benzene polyacid esters according to any one of claims 1 to 3, characterized in that: The catalyst loading pool is loaded with spherical catalysts.

7. The reaction device for synthesizing C8-13 alcohol benzene polyacid ester by continuous method according to any one of claims 1 to 3, characterized in that: A liquid convection cavity is left below the catalyst loading pool.

8. The reaction device for synthesizing C8-13 alcohol benzene polyacid ester by continuous method according to any one of claims 1 to 3, characterized in that: A heating jacket is arranged on the periphery of the catalytic reaction section.

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