A continuous process for the production of TMPO by reactive distillation condensation and tubular reactor cracking

Abstract

The utility model discloses a kind of reaction rectification condensation and tubular reactor cleavage continuous preparation 3-hydroxymethyl-3-ethyl oxetane (TMPO) device, diethyl carbonate and trimethylolpropane are transported to raw material preheater by metering pump after mixing, enter reaction rectification column catalytic rectification section and carry out condensation reaction, by-product ethanol is taken out from column top, promote reaction positive direction to carry out, six-membered ring intermediate is taken out from column bottom and is transported to tubular reactor by column bottom pump, carry out cleavage reaction, generated TMPO crude product and CO2 enter gas-liquid separator and separate, TMPO crude product enters TMPO rectification column and is purified, TMPO product is taken out from column top.The utility model reaction rectification condensation technology, combine reaction and rectification, reduce equipment investment, improve conversion rate to more than 99%.Using tubular reactor cleavage preparation TMPO process, compared with kettle type batch reactor, energy consumption is reduced, realize the efficient continuous preparation of TMPO.

Description

Technical Field

[0001] This utility model relates to the field of chemical production equipment, specifically a device for the continuous preparation of TMPO by reactive distillation condensation and tubular reactor pyrolysis. Background Technology

[0002] 3-Hydroxymethyl-3-ethyloxetane (TMPO) is an excellent UV-curable monomer material, applicable to UV inks, UV coatings, and UV adhesives. Oxetane monomers are excellent photocatalytic cationic polymers. Mixing 3-hydroxymethyl-3-ethyloxetane photoinitiator with cationic polymers in a specific ratio produces UV-curable films with excellent resistance to heat treatment and sterilization. The resulting novel oxetane-based photocurable cationic resins cure faster than epoxy resins and can be formulated into cured products with good processability, resistance to water, chemicals, and impact agents. Therefore, TMPO offers greater environmental, technological, and economic advantages compared to other materials.

[0003] Zhao Xiaoxia et al. (Zhao Xiaoxia, Wei Wenlong, Chang Honghong, Wang Zhizhong. Process study on synthesis of 3-hydroxymethyl-3-ethyloxetane from diethyl carbonate [J]. Journal of Taiyuan University of Technology, 2008, 39(1):159-161.) conducted transesterification reaction using diethyl carbonate and trimethylolpropane as raw materials under KOH catalysis. A batch reaction was used. When the molar ratio of diethyl carbonate to trimethylolpropane was 1:1, the yield of TMPO was 60.6%, and the purity of TMPO was 91.33%.

[0004] Batch reactions suffer from low reaction efficiency, numerous byproducts, and high energy consumption. In existing technologies, condensation reactors and cracking reactors are set up independently, requiring intermediate product transfer and repeated heating, which increases equipment investment and energy consumption, and makes it difficult to achieve continuous production through batch operation.

[0005] Therefore, to address the aforementioned problems, a continuous TMPO preparation apparatus combining reactive distillation condensation and tubular reactor pyrolysis is proposed. This process provides a reactive distillation condensation technology that combines reaction and distillation, reducing equipment investment and increasing the conversion rate to over 99%. Compared to batch reactors, the tubular reactor pyrolysis process for TMPO preparation reduces energy consumption, enabling efficient and continuous TMPO preparation. Utility Model Content

[0006] The purpose of this invention is to provide a device for the continuous preparation of 3-hydroxymethyl-3-ethyloxetane (TMPO) by reactive distillation condensation and tubular reactor pyrolysis. Diethyl carbonate and trimethylolpropane are mixed in a feed preheater via a metering pump and then enter the catalytic distillation section of a reactive distillation column for condensation. Ethanol, a byproduct, is collected from the top of the column to promote the forward reaction. A six-membered ring intermediate is collected from the bottom of the column and pumped to a tubular reactor for pyrolysis. The resulting crude TMPO is separated from CO2 in a gas-liquid separator. The crude TMPO is then purified in a TMPO refining column, and the TMPO product is collected from the top of the column.

[0007] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0008] This invention, based on a thorough study of the process route, reaction mechanism, and catalyst, combines reactive distillation condensation with tubular reactor pyrolysis to improve the yield and purity of TMPO.

[0009] This invention combines reaction and distillation to achieve simultaneous condensation reaction and ethanol removal, reducing equipment investment and increasing reaction conversion rate to over 99%. Furthermore, the tubular reactor pyrolysis continuous TMPO preparation process avoids intermediate cooling followed by reheating, thus reducing energy consumption. Attached Figure Description

[0010] Figure 1 This is a process flow diagram of this utility model.

[0011] The reference numerals and names in the figure are as follows:

[0012] 1. Diethyl carbonate storage tank; 2. Trimethylolpropane storage tank; 3. Metering pump one; 4. Metering pump two; 5. Raw material preheater; 6. Reactive distillation column; 7. Water-cooled heat exchanger one; 8. Bottom pump one; 9. Tubular reactor; 10. Bottom pump two; 11. Gas-liquid separator; 12. Bottom pump three; 13. TMPO purification column; 14. Water-cooled heat exchanger two. Detailed Implementation

[0013] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0014] 1. As attached Figure 1As shown, this utility model provides a continuous TMPO preparation device using reactive distillation condensation and tubular reactor pyrolysis. It includes a diethyl carbonate storage tank 1 and a trimethylolpropane storage tank 2. Its features are: the diethyl carbonate storage tank (1) and the trimethylolpropane storage tank (2) are respectively connected to a raw material preheater 5 via metering pump one (3) and metering pump two (4); the raw material preheater 5 is connected to a reactive distillation column 6 via a pipeline; the top of the reactive distillation column 6 is connected to a water-cooled heat exchanger one (7); the bottom of the column is connected to a tubular reactor 9 via a bottom pump one (8); the tubular reactor 9 is connected to a gas-liquid separator 11 via a bottom pump two (10); the gas-liquid separator 11 is connected to a TMPO purification column 13 via a bottom pump three (12); and the top of the TMPO purification column 13 is connected to a water-cooled heat exchanger two (14).

[0015] Specifically, the preheating temperature of the raw material preheater 5 is 60-80℃.

[0016] Specifically, the reactive distillation column 6 includes, from top to bottom, a column top, a rectification section, a material inlet, a catalytic rectification section with a solid base catalyst, a stripping section, and a column bottom.

[0017] Specifically, the gas-liquid separator 11 is a gravity separator or a cyclone separator.

[0018] Specifically, the reaction temperature of reactive distillation column 6 is 80-120℃, and the operating pressure is 0.1-0.5MPa.

[0019] Specifically, the tubular reactor 9 is made of 316L stainless steel with a length-to-diameter ratio of 20:1. It is equipped with an external electric heating mantle for temperature control, and the pyrolysis temperature is 160-190℃. The operating pressure is ≤1.0MPa.

[0020] Working Principle: Diethyl carbonate storage tank 1 and trimethylolpropane storage tank 2 are connected to feed preheater 5 via metering pump 3 and metering pump 4, respectively. The feed is uniformly mixed in feed preheater 5 and then fed into reactive distillation column 6 for reaction. Diethyl carbonate and trimethylolpropane undergo a condensation reaction under the action of a catalyst. The light component, ethanol, is collected from the top of reactive distillation column 6 via water-cooled heat exchanger 7. The heavy component, a six-membered ring intermediate, is fed into tubular reactor 9 via bottom pump 8 for cracking. The resulting crude TMPO and CO2 are separated by bottom pump 10 in gas-liquid separator 11. Gas-liquid separator 11 discharges CO2, and the crude TMPO is fed into TMPO refining column 13 via bottom pump 12. The TMPO product is collected from the top of TMPO refining column 13 via water-cooled heat exchanger 14. The combination of reaction and distillation reduces equipment investment and improves reaction efficiency. The continuous TMPO preparation process using tubular reactor cracking yields a high TMPO yield.

[0021] In the description of this utility model, it should be noted that the terms "upper," "lower," "inner," "outer," "front," "rear," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0022] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," and "connected," etc., should be interpreted broadly. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

Claims

1. A continuous TMPO preparation apparatus consisting of reactive distillation condensation and tubular reactor pyrolysis, comprising a diethyl carbonate storage tank (1) and a trimethylolpropane storage tank (2), characterized in that: The diethyl carbonate storage tank (1) and the trimethylolpropane storage tank (2) are connected to the raw material preheater (5) via metering pump one (3) and metering pump two (4), respectively. The raw material preheater (5) is connected to the reactive distillation column (6) via pipeline. The top of the reactive distillation column (6) is connected to the water-cooled heat exchanger one (7). The bottom of the column is connected to the tubular reactor (9) via bottom pump one (8). The tubular reactor (9) is connected to the gas-liquid separator (11) via bottom pump two (10). The gas-liquid separator (11) is connected to the TMPO purification column (13) via bottom pump three (12). The top of the TMPO purification column (13) is connected to the water-cooled heat exchanger two (14).

2. The apparatus for continuous preparation of TMPO by reactive distillation condensation and tubular reactor pyrolysis according to claim 1, characterized in that: The preheating temperature of the raw material preheater (5) is 60-80℃.

3. The apparatus for continuous preparation of TMPO by reactive distillation condensation and tubular reactor pyrolysis according to claim 1, characterized in that: The reactive distillation column (6) includes, from top to bottom, a column top, a rectification section, a catalytic rectification section with a solid base catalyst, a stripping section, and a column bottom.

4. The apparatus for continuous preparation of TMPO by reactive distillation condensation and tubular reactor pyrolysis according to claim 1, characterized in that: The gas-liquid separator (11) is a gravity separator or a cyclone separator.

5. The apparatus for continuous preparation of TMPO by reactive distillation condensation and tubular reactor pyrolysis according to claim 3, characterized in that: The reaction distillation column (6) has a reaction temperature of 80-120℃ and an operating pressure of 0.1-0.5MPa.

6. The apparatus for continuous preparation of TMPO by reactive distillation condensation and tubular reactor pyrolysis according to claim 1, characterized in that: The tubular reactor (9) is made of 316L stainless steel with a length-to-diameter ratio of 20:

1. It is equipped with an external electric heating jacket for temperature control, and the pyrolysis temperature is 160-190℃. The operating pressure is ≤1.0MPa.

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