Solid catalyst reactive distillation device for producing ethyl methyl oxalate and diethyl oxalate
By designing a solid catalyst reaction distillation device, the problems of high equipment investment, high production cost and limited conversion rate selectivity in the production process of diethyl oxalate in the prior art are solved, and the process flow is simplified, reducing energy consumption and reducing production costs are achieved.
Patent Information
- Application Number
- CN202421322984.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-12
- Publication Date
- 2025-02-28
- Estimated Expiration
- 2034-06-12
AI Technical Summary
The prior art has problems such as high equipment investment, high production costs, harsh reaction conditions, and limited conversion and selectivity when producing diethyl oxalate.
A solid catalyst reaction distillation device is designed, including a dimethyl oxalate storage tank, an ethanol storage tank, a pre-reactor, a reaction distillation tower and a methyl ethyl oxalate conversion reactor. The device realizes complete conversion of dimethyl oxalate and arbitrary adjustment of the ratio of methyl oxalate to diethyl oxalate through a catalytic distillation section with a solid catalyst and a conversion reactor of methyl oxalate.
The device simplifies the process flow, reduces energy consumption and equipment investment, improves the selectivity and conversion rate of diethyl oxalate, reduces production costs, and reduces the generation of solid waste, and improves safety and environmental protection performance.
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Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of production of ethyl methyl oxalate and diethyl oxalate, in particular to a solid catalyst reaction distillation device for producing ethyl methyl oxalate and diethyl oxalate. Background Art
[0002] Ethyl methyl oxalate (diethyl ester) is an important organic chemical raw material and methyl / ethylating agent, which can react with fatty acid esters, amides or aniline compounds and many heterocyclic compounds to undergo various condensation reactions. Ethyl methyl oxalate can be used as a lithium battery electrolyte solvent as an asymmetric oxalate. It can be used in the pharmaceutical industry to synthesize the hormone thymosine, and is an intermediate for the manufacture of drugs such as phenobarbital, azathioprine, long-acting sulfonamides, sulfamethoxazole, carboxyphenyl penicillin, ampicillin, chloroquine lactate, thiabendazole, and ketone esters. Secondly, ethyl methyl oxalate (diethyl ester) can also be used to manufacture plastic accelerators, cellulose and fragrance solvents, textile auxiliaries, dye intermediates and dye-sensitized battery additives, bearing high-pressure resistant lubricants, etc. Ethyl methyl oxalate (diethyl ester) can also react with corroded carbonate matrix to form a unique oxalate surface layer to prevent further corrosion of the matrix, and directly replace oxalic acid in the wood chip papermaking industry or extract hemicellulose sugar from plant fibers. Ethyl methyl oxalate can be used to prepare oxalic acid and ethyl methyl carbonate, which have important chemical applications, through simple hydrolysis and decarbonylation reactions.
[0003] At present, the methods for industrial production of diethyl oxalate at home and abroad are mainly traditional esterification, carbon monoxide catalytic oxidative coupling and transesterification. The production process of synthesizing diethyl oxalate by traditional esterification is relatively simple. Since the esterification reaction is a reversible reaction, in order to improve the yield of diethyl oxalate, a dehydrating agent must be used to remove the crystal water in the raw material oxalic acid and the water in the reaction system, so that the reaction proceeds in the forward direction, which increases equipment investment and production costs. The preparation of diethyl oxalate by carbon monoxide catalytic oxidative coupling is to use carbon monoxide as a raw material through methyl nitrite or ethyl nitrite, and under the action of a corresponding catalyst, oxidative coupling generates dimethyl oxalate or diethyl oxalate. The reaction conditions of this method are very harsh, and it needs to be carried out under high pressure conditions. The process flow is long, the equipment investment is high, and the equipment is easily corroded and the catalyst is lost. The transesterification method produces diethyl oxalate, and the raw materials are easy to obtain, and there is no water generation in the process, which avoids the use of water-carrying agents, reduces the dehydrating agent recovery device, reduces energy consumption, and reduces environmental pollution. However, there is a thermodynamic equilibrium in this reaction, which will limit the conversion rate and selectivity.
[0004] Therefore, in view of the above problems, a solid catalyst reaction distillation device for producing ethyl methyl oxalate and diethyl oxalate is proposed, which continuously extracts methanol, makes the reaction proceed in a forward direction, and can completely convert dimethyl oxalate. At the same time, the device is also provided with a ethyl methyl oxalate conversion reactor, which can arbitrarily adjust the ratio of ethyl methyl oxalate and diethyl oxalate, and obtain the required product in a targeted manner. The device has the advantages of simple process flow, low equipment investment, and low production cost. Utility Model Content
[0005] The utility model aims to provide a solid catalyst reaction distillation device for producing ethyl methyl oxalate and diethyl oxalate, comprising a dimethyl oxalate storage tank and an ethanol storage tank, wherein the dimethyl oxalate storage tank and the ethanol storage tank are respectively connected to a raw material preheater, the raw material preheater is connected to a pre-reactor, the pre-reactor is connected to a reaction distillation tower through a pipeline, the top of the reaction distillation tower is connected to a first water-cooled heat exchanger, the bottom of the tower is connected to a reboiler and a ethyl methyl oxalate conversion reactor, and the ethyl methyl oxalate conversion reactor is connected to a second water-cooled heat exchanger.
[0006] Compared with the prior art, the beneficial effects of the utility model are as follows:
[0007] The utility model combines a pre-reactor with a reaction distillation device on the basis of fully studying the process route, reaction mechanism and catalyst, completely converts dimethyl oxalate, and further improves the selectivity of diethyl oxalate. A methyl ethyl oxalate conversion reactor is added, and the ratio of methyl ethyl oxalate and diethyl oxalate can be adjusted arbitrarily. The process flow is simple, the energy consumption is low, and the equipment investment is small, thereby reducing the production cost.
[0008] The utility model is provided with a catalytic distillation section with a solid catalyst, which can fully carry out the reaction and improve the conversion rate and selectivity. On the other hand, it is easy to separate from the product and can be recycled, reducing the generation of solid waste, reducing the safety and environmental protection problems caused by emissions and the occupational health problems of operators. BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Figure 1 It is a structural schematic diagram of the utility model.
[0010] The reference numerals and names in the figures are as follows:
[0011] 1. Dimethyl oxalate storage tank; 2. Ethanol storage tank; 3. Metering pump 1; 4. Metering pump 2; 5. Raw material preheater; 6. Prereactor; 7. Reaction distillation tower; 8. Water-cooled heat exchanger 1; 9. Bottom reboiler; 10. Bottom pump; 11. Methyl oxalate conversion reactor; 12. Water-cooled heat exchanger 2. DETAILED DESCRIPTION
[0012] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0013] As attached Figure 1 As shown, the utility model provides a solid catalyst reaction distillation device for producing ethyl methyl oxalate and diethyl oxalate, comprising a dimethyl oxalate storage tank 1 and an ethanol storage tank 2. The dimethyl oxalate storage tank 1 and the ethanol storage tank 2 are respectively connected to a raw material preheater 5, the raw material preheater 5 is connected to a pre-reactor 6, the pre-reactor 6 is connected to a reaction distillation tower 7 through a pipeline, the top of the reaction distillation tower 7 is connected to a water-cooled heat exchanger 1 8, the bottom of the tower is connected to a reboiler 9 and a ethyl methyl oxalate conversion reactor 11, and the ethyl methyl oxalate conversion reactor 11 is connected to a water-cooled heat exchanger 2 12.
[0014] Specifically, a metering pump 1 3 is connected between the dimethyl oxalate storage tank 1 and the raw material preheater 5, a metering pump 2 4 is connected between the ethanol storage tank 2 and the raw material preheating reactor 5, and a tower bottom pump 10 is connected between the tower bottom of the reaction distillation tower 7 and the methyl ethyl oxalate conversion reactor 11. In this way, the input amount and input ratio of the raw materials can be accurately controlled, which is conducive to the reaction and the generation of the product, as well as the further conversion of the intermediate product, and the yield is improved.
[0015] Specifically, the reactive distillation tower 7 includes, from top to bottom, a tower top, a distillation section, a material inlet, a catalytic distillation section with a solid catalyst, a stripping section and a tower bottom.
[0016] Specifically, the reaction distillation tower 7 is a normal pressure or pressurized distillation tower with mild reaction conditions and does not require high energy consumption. The catalyst used in the catalytic distillation section with a solid catalyst can effectively react dimethyl oxalate with ethanol, thereby improving the conversion rate and selectivity.
[0017] Working principle: The utility model is provided with a catalytic distillation section with a solid catalyst and a methyl ethyl oxalate conversion reactor. After the dimethyl oxalate storage tank 1 and the ethanol storage tank 2 are connected to the raw material preheater 5 through the metering pump 1 3 and the metering pump 2 4 respectively, they enter the pre-reactor 6 for reaction, and the reacted mixture enters the material inlet of the reaction distillation tower 7 through the pipeline. The light component methanol and part of the ethanol flow to the top of the tower through the distillation section and are extracted through the water-cooled heat exchanger 8. The heavy components methyl ethyl oxalate, diethyl oxalate, and unreacted dimethyl oxalate and ethanol pass through the catalytic distillation section with a solid catalyst, and an ester exchange reaction occurs under the action of the catalyst. The generated methanol and a small amount of unreacted ethanol continue to move upward and are extracted from the top of the tower. All the generated methyl ethyl oxalate, diethyl oxalate, and a small amount of unreacted dimethyl oxalate and ethanol flow downward through the stripping section to the bottom of the tower. A part of it passes through the tower bottom reboiler 9 and returns to the tower bottom to react again, and the other part passes through the tower bottom pump 10, enters the methyl ethyl oxalate conversion reactor 11, and is then extracted through the water-cooled heat exchanger 12. The methyl ethyl oxalate conversion reactor can completely convert dimethyl oxalate, and the ratio of methyl ethyl oxalate and diethyl oxalate can be adjusted arbitrarily, which can not only improve the conversion rate of the reaction, but also efficiently utilize the reaction heat to achieve continuous and energy-saving production.
[0018] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front section", "rear end", "two ends", "one end", "the other end" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.
[0019] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. 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 it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
Claims
1. A solid catalyst reaction distillation device for producing ethyl methyl oxalate and diethyl oxalate, comprising a dimethyl oxalate storage tank (1) and an ethanol storage tank (2), characterized in that: The dimethyl oxalate storage tank (1) and the ethanol storage tank (2) are respectively connected to a raw material preheater (5), the raw material preheater (5) is connected to a pre-reactor (6), the pre-reactor (6) is connected to a reaction distillation tower (7) through a pipeline, the top of the reaction distillation tower (7) is connected to a water-cooled heat exchanger 1 (8), the bottom of the tower is connected to a reboiler (9) and a methyl ethyl oxalate conversion reactor (11), and the methyl ethyl oxalate conversion reactor (11) is connected to a water-cooled heat exchanger 2 (12).
2. A solid catalyst reactive distillation device for producing ethyl methyl oxalate and diethyl oxalate according to claim 1, characterized in that: A metering pump (3) is connected between the dimethyl oxalate storage tank (1) and the raw material preheater (5).
3. A solid catalyst reactive distillation device for producing ethyl methyl oxalate and diethyl oxalate according to claim 1, characterized in that: A second metering pump (4) is connected between the ethanol storage tank (2) and the raw material preheater (5).
4. A solid catalyst reactive distillation device for producing ethyl methyl oxalate and diethyl oxalate according to claim 1, characterized in that: A bottom pump (10) is connected between the bottom of the reactive distillation tower (7) and the methyl ethyl oxalate conversion reactor (11).
5. A solid catalyst reactive distillation device for producing ethyl methyl oxalate and diethyl oxalate according to claim 1, characterized in that: The reactive distillation tower (7) comprises, from top to bottom, a tower top, a distillation section, a material inlet, a catalytic distillation section with a solid catalyst, a stripping section and a tower bottom.