Preparation method and device of methyl monoethanolamine and methyldiethanolamine or dimethylethanolamine

Abstract

The invention provides a preparation method and device of methyl monoethanolamine and methyldiethanolamine or dimethylethanolamine, and the preparation method comprises the following steps: ethylene oxide and raw materials react in a reactor, and one part of a material discharged from the top of the reactor enters the middle part of a downstream deamination tower; a stabilizer A and a stabilizer B are introduced into the lower part of the deamination tower, a material obtained at the bottom of the deamination tower sequentially enters the middle part of a stabilizer A removal tower, a material obtained at the bottom of the stabilizer A removal tower enters the middle part of a product light component removal tower, and the top of the product light component removal tower is subjected to condensation treatment to obtain a first product; or materials obtained at the bottom of the product light component removal tower enter a product refining tower, and a second product is obtained at the top of the product refining tower. The raw material conversion rate is increased from about 95% to 99.9% or above, the processing cost is reduced by about 10,000,000 yuan every year by taking 20,000 tons / year productivity as an example, and the economic benefit is increased.

Description

Technical Field

[0001] The invention belongs to the field of organic synthesis, and in particular relates to a preparation method and a device for methyl monoethanolamine and methyl diethanolamine or dimethylethanolamine. Background Art

[0002] The methylethanolamine series products mainly include N-methylmonoethanolamine (MMEA), N-methyldiethanolamine (MDEA) and N,N-dimethylethanolamine (DMEA).

[0003] Methylethanolamine series products are a new type of solvent with excellent performance for selective desulfurization and decarbonization, with the advantages of high selectivity, low solvent consumption, significant energy saving effect, and non-degradable. It is widely used in desulfurization and purification emulsifiers for oilfield gas and coal gas, acid gas absorbents, acid-base control agents, and polyurethane foam catalysts. It can remove carbon dioxide from synthetic ammonia with the participation of activators, so it has been gradually promoted in the absorption of carbon dioxide in flue gas in recent years. In addition, MDEA can also be used as a semi-finished product of pesticides, emulsifiers, fabric auxiliaries, intermediates of anti-tumor drug hydrochloric acid mustard, catalysts for carbamate coatings, fiber auxiliaries, etc. At the same time, it is also a drying accelerator for paints.

[0004] At present, methylethanolamine series products are all prepared by amination reaction of methylamine (monomethylamine or dimethylamine) and ethylene oxide. The current production method has problems such as backward intermittent reaction, untimely heat removal of reaction heat, poor product distillation process, etc., resulting in low raw material conversion rate, low product yield, high energy consumption and poor product stability, which affects economic benefits and product competitiveness.

[0005] How to take effective measures to solve the problems existing in the current production methods, and improve the raw material conversion rate, product yield, product stability and reduce energy consumption are the key contents of this technical solution. Invention content In view of this, the present invention aims to provide a method and device for preparing methyl monoethanolamine and methyl diethanolamine or dimethylethanolamine, so as to solve at least one technical problem in the background technology.

[0007] To achieve the above object, the technical solution created by the present invention is implemented as follows: A method for preparing methyl monoethanolamine and methyl diethanolamine or dimethylethanolamine comprises the following steps: Ethylene oxide and raw materials react in the reactor, and part of the discharge from the top of the reactor enters the middle of the downstream deamine tower; the other part of the discharge from the top of the reactor or the material drawn out from the side line is cooled and circulated back to the bottom of the reactor; Stabilizer A and stabilizer B are introduced below the deamine tower, the material obtained at the bottom of the deamine tower is sequentially introduced into the middle of the destabilizer A tower, the material obtained at the bottom of the destabilizer A tower is introduced into the middle of the product light-removing tower, and the top of the product light-removing tower is condensed to obtain the first product; If the raw material is monomethylamine, the first product is methyl monoethanolamine, the material obtained at the bottom of the product light removal tower enters the product refining tower, and the second product is methyl diethanolamine at the top of the product refining tower; If the raw material is dimethylamine, the first product is dimethylethanolamine.

[0008] Furthermore, a plurality of feed ports are provided below and at the bottom of the reactor; ethylene oxide and raw materials enter the reactor through the feed ports; Preferably, 1 to 15 feed inlets are provided below the reactor, and 1 feed inlet is provided at the bottom of the reactor; And / or, a plurality of discharge ports are provided below and at the bottom of the reactor; Preferably, 1 to 10 discharge ports are provided in the middle and upper part of the reactor, and 1 discharge port is provided at the top of the reactor. The reactor type is one of a fixed bed reactor, a tubular reactor or a microchannel reactor.

[0009] The present application uses multi-point feeding to, on the one hand, fully distribute the raw materials ethylene oxide and methylamine inside the reactor, and on the other hand, reduce the possibility of suppressing the reaction conversion rate due to excessive local concentration caused by single-point feeding of raw materials, thereby achieving the purpose of improving the raw material conversion rate.

[0010] The reactor is provided with material extraction ports at the middle upper part and the top part. The middle upper part extraction port or the top extraction port can be opened by judging the reaction conversion rate, and the operation is flexible.

[0011] Furthermore, the operating pressure of the reactor is 3.0~5.5MPaG, and the operating temperature is 100~200°C.

[0012] Furthermore, the reaction circulation ratio of the material circulation amount of the other part of the top discharge of the reactor or the material extracted from the side line after cooling to the sum of ethylene oxide and the raw material is 50-500.

[0013] Furthermore, the operating pressure of the deamine tower is 0.3~0.6MPaG, and the operating temperature is 130~150°C; And / or, stabilizer A includes one or more of water, n-hexane, isohexane, cyclohexane, n-heptane, isoheptane, n-octane or isooctane, and the injection amount of stabilizer A is 1.0% to 50.0% of the product output. If the raw material is monomethylamine, the product output is the sum of the outputs of methyl monoethanolamine and methyl diethanolamine. If the raw material is dimethylamine, the product output is the output of dimethylethanolamine.

[0014] And / or, stabilizer B includes one or more of monoethanolamine, diethanolamine, triethanolamine, monoethylhydroxylamine, diethylhydroxylamine, and triethylhydroxylamine, and the injection amount of stabilizer B is 0.001% to 1.0% of the product output.

[0015] Furthermore, the top material of the deamine tower is condensed and then circulated back to the interior of the deamine tower or enters the reactor as a raw material; And / or, the material obtained at the bottom of the deamine tower enters the middle of the destabilizer A tower, and the material at the top of the tower is cooled to obtain stabilizer A or enter the destabilizer A tower.

[0016] And / or, the operating temperature of the destabilizer tower A is 42~150°C, and the operating pressure is 5~20KPaA.

[0017] And / or, the material obtained at the bottom of the destabilizer A tower enters the middle of the product light-removal tower, stabilizer B is introduced to the bottom of the product light-removal tower, and the top material of the product light-removal tower enters the condensation to obtain the product or refluxes into the product light-removal tower; The operating temperature of the product lightness removal tower is 55~180℃, and the operating pressure is 2~20KPaA.

[0018] And / or, the operating temperature of the product refining tower is 100~180℃, and the operating pressure is 2~10KPaA.

[0019] And / or, if the raw material is monomethylamine, the material obtained at the bottom of the product light-removing tower enters the middle part of the product refining tower, the top material of the product refining tower is condensed to obtain the product or refluxes into the refining tower, most of the material distilled from the top of the condensation tower, and the non-condensable gas enters the vacuum system, and the bottom material of the product light-removing tower is the heavy component.

[0020] And / or, if the raw material is dimethylamine, the heavy components are output from the bottom of the product lightness removal tower.

[0021] The device used in the above-mentioned method for preparing methyl monoethanolamine and methyl diethanolamine or dimethylethanolamine comprises a reactor, an amine removal tower, a stabilizer removal tower A, a product light removal tower, and a product refining tower; A raw material inlet pipe is provided at the bottom or below of the reactor; An ethylene oxide inlet pipe is provided at the bottom or below of the reactor; The top of the reactor is connected to the middle of the deamine tower, the bottom of the deamine tower is connected to the destabilizer A tower, and the bottom of the destabilizer A tower is connected to the middle of the product light-removal tower; If the raw material is monomethylamine, the top output material of the product light-removing tower is cooled and then output as the first product, and the bottom of the product light-removing tower is connected to the middle of the product refining tower; the top output material of the product refining tower is cooled and then output as the second product.

[0022] If the raw material is dimethylamine, the material output from the top of the product light-removal tower is cooled and then output as the first product, and the heavy component is output from the bottom of the product light-removal tower.

[0023] Furthermore, a first valve is provided on both the raw material inlet pipe and the ethylene oxide inlet pipe; And / or, the top of the reactor is connected to the middle of the deamine tower through a pipeline, and the top of the reactor is connected to the first branch pipe and the second branch pipe respectively through a reflux pipeline; the first branch pipe is connected to the upper part of the reactor; the second branch pipe is connected to the bottom of the reactor; And / or, a second valve is provided on the return pipe; And / or, a third valve is provided on the first branch pipe; And / or, a reaction circulation heat collector and a reaction circulation pump are sequentially arranged on the second branch pipe.

[0024] The present application relates to an amination reaction, which is a highly exothermic reaction. During the reaction, heat must be removed in a timely manner, otherwise excessive local heat release will occur, causing equipment overheating and the risk of equipment container rupture.

[0025] The reactor of the present application is provided with a material extraction port in the upper middle part and the top, and the high-temperature material is sent to the reaction cycle heat collector, and the heat is used to generate low-pressure steam inside the reaction cycle heat collector, thereby withdrawing the reaction heat. The present application can generate low-pressure steam by setting a reaction cycle heat collector, and the steam can be used for heating the reboiler of the distillation system, thereby achieving the purpose of reducing production energy consumption.

[0026] Furthermore, the top of the deamine tower is connected to the first reflux tank through a pipeline, and a first condenser is provided on the pipeline between the first reflux tank and the deamine tower; the bottom of the first reflux tank is connected to the upper part of the deamine tower through a pipeline, and the bottom of the first reflux tank is connected to the raw material inlet pipe through a pipeline; A stabilizer inlet A pipeline and a first stabilizer inlet B pipeline are respectively provided below the deamine tower; And / or, the bottom of the deamine tower is connected to the middle of the destabilizer A tower through a pipeline; the bottom of the deamine tower is connected to the bottom of the deamine tower through a pipeline, and a first heat exchanger is provided on the pipeline connecting the bottom of the deamine tower and the bottom of the deamine tower; And / or, the top of the destabilizer tower A is connected to the second reflux tank through a pipeline; a second condenser is provided on the pipeline between the deamine tower and the second reflux tank; the bottom of the destabilizer tower A is connected to the middle of the product light removal tower through a pipeline; And / or, the bottom of the second reflux tank is connected to the top of the destabilizer A tower through a pipeline, the bottom of the second reflux tank outputs stabilizer A through a pipeline, the bottom of the destabilizer A tower is connected to the bottom of the destabilizer A tower through a pipeline, and a second heat exchanger is provided on the pipeline between the bottom of the destabilizer A tower and the bottom of the destabilizer A tower.

[0027] Furthermore, a second stabilizer B inlet pipeline is provided below the product lightness removal tower; And / or, a third condenser is provided on the pipeline between the product light removal tower and the third reflux tank, the bottom of the third reflux tank is connected to the upper part of the product light removal tower through a pipeline, the bottom of the third reflux tank outputs the first product, and the upper part of the third reflux tank is connected to the vacuum system; And / or, the bottom of the product light-removal tower is connected to the middle of the product light-removal tower through a pipeline, and the bottom of the product light-removal tower is connected to the bottom of the product light-removal tower through a pipeline; a third heat exchanger is provided on the pipeline between the bottom of the product light-removal tower and the bottom of the product light-removal tower; And / or, a fourth condenser is provided on the pipeline between the product refining tower and the fourth reflux tank; the bottom of the fourth reflux tank is connected to the upper part of the product refining tower through a pipeline, the bottom of the fourth reflux tank outputs the second product, and the upper part of the fourth reflux tank is connected to the vacuum system; And / or, the bottom of the product refining tower is connected to the bottom of the product refining tower through a pipeline, and a fourth heat exchanger is provided on the pipeline between the bottom of the product refining tower and the bottom of the product refining tower; And / or, if the product is monomethylamine, a first heavy component output pipeline is provided at the bottom of the product refining tower; If the product is dimethylamine, a second heavy component output pipeline is provided at the bottom of the product light component removal tower.

[0028] Compared with the prior art, the method and device for preparing methylmonoethanolamine and methyldiethanolamine or dimethylethanolamine created by the present invention have the following advantages: 1. This application solves the problem of low raw material reaction conversion rate by setting up multi-point feeding of the reactor. Through this process technology, the raw material conversion rate is increased from about 95% to more than 99.9%. Taking 20,000 tons / year production capacity as an example, the annual processing cost is reduced by about 10 million yuan, which improves the economic benefits.

[0029] 2. This application is equipped with an external circulation heat extraction system for the reactor, which solves the problem of production energy consumption. Taking a production capacity of 20,000 tons / year as an example, through this process technology, steam consumption is reduced by about 3.0 t / h, and annual processing costs are reduced by about 6.8 million yuan.

[0030] 3. This application solves the problem of low product yield by providing an injection method of stabilizer A. Through this process technology, the product yield is increased from about 92% to more than 99%. Taking a production capacity of 20,000 tons / year as an example, the annual economic benefit increases by about 20 million yuan. In addition, the problem of poor product stability is solved by providing an injection method of stabilizer B. Through this process technology, the color of the product can be stably maintained below 20, and basically no over-standard situation will occur. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The drawings constituting part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments and descriptions of the present invention are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:

[0032] Figure 1 A schematic diagram of a device used in the method for preparing methyl monoethanolamine or methyl diethanolamine described in Example 1 of the present invention; Figure 2 A schematic diagram of the device used in the method for preparing dimethylethanolamine described in Example 7 of the present invention.

[0033] Description of reference numerals: 1. Reactor; 2. Reaction cycle heat collector; 3. Reaction circulation pump; 4. Deamine tower; 5. Destabilizer A tower; 6. Product lightness removal tower; 7. Product refining tower; 8. Third reflux tank; 9. Fourth reflux tank; 10. First valve; 11. Second valve; 12. Third valve; 13. First condenser; 14. First reflux tank; 15. First heat exchanger; 16. Second reflux tank; 17. Second condenser; 18. Second heat exchanger; 19. Fourth heat exchanger; 20. Third condenser; 21. Third heat exchanger; 22. Fourth condenser. DETAILED DESCRIPTION

[0034] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0035] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0036] Implementation Case 1: A methyl monoethanolamine and methyl diethanolamine preparation device comprises a reactor 1, an amine removal tower 4, a destabilizer A tower 5, a product light-removing tower 6, and a product refining tower 7; a raw material inlet pipe is provided at the bottom or below of the reactor 1; an ethylene oxide inlet pipe is provided at the bottom or below of the reactor 1; the top of the reactor 1 is connected with the middle of the amine removal tower 4, the bottom of the amine removal tower 4 is connected with the destabilizer A tower 5, and the bottom of the destabilizer A tower 5 is connected with the middle of the product light-removing tower 6; if the raw material is monomethylamine, the top output material of the product light-removing tower 6 is cooled and then output as a first product; the bottom of the product light-removing tower 6 is connected with the middle of the product refining tower 7; the top output material of the product refining tower 7 is cooled and then output as a second product.

[0037] A first valve 10 is provided on both the raw material inlet pipe and the ethylene oxide inlet pipe; the top of the reactor 1 is connected to the middle of the deamine tower 4 through a pipeline, and the top of the reactor 1 is connected to the first branch pipe and the second branch pipe respectively through a reflux pipeline; the first branch pipe is connected to the upper part of the reactor 1; the second branch pipe is connected to the bottom of the reactor 1, a second valve 11 is provided on the reflux pipeline, and a third valve 12 is provided on the first branch pipe; a reaction cycle heat collector 2 and a reaction cycle pump 3 are provided on the second branch pipe in sequence.

[0038] The top of the deamine tower 4 is connected to the first reflux tank 14 through a pipeline, and a first condenser 13 is provided on the pipeline between the first reflux tank 14 and the deamine tower 4; the bottom of the first reflux tank 14 is connected to the upper part of the deamine tower 4 through a pipeline, and the bottom of the first reflux tank 14 is connected to the raw material inlet pipe through a pipeline; the lower part of the deamine tower 4 is provided with a stabilizer A inlet pipeline and a first stabilizer B inlet pipeline; The bottom of the deamine tower 4 is connected to the middle of the destabilizer A tower 5 through a pipeline; the bottom of the deamine tower 4 is connected to the bottom of the deamine tower 4 through a pipeline, and a first heat exchanger 15 is provided on the pipeline connecting the bottom of the deamine tower 4 and the bottom of the deamine tower 4; The top of the destabilizer A tower 5 is connected to the second reflux tank 16 through a pipeline; a second condenser 17 is provided on the pipeline between the deamine tower 4 and the second reflux tank 16; the bottom of the destabilizer A tower 5 is connected to the middle part of the product light removal tower 6 through a pipeline, the bottom of the second reflux tank 16 is connected to the top of the destabilizer A tower 5 through a pipeline, and the bottom of the second reflux tank 16 outputs stabilizer A through a pipeline; the bottom of the destabilizer A tower 5 is connected to the bottom of the destabilizer A tower 5 through a pipeline, and a second heat exchanger 18 is provided on the pipeline between the bottom of the destabilizer A tower 5 and the bottom of the destabilizer A tower 5.

[0039] A second stabilizer B inlet pipeline is provided below the product light-removing tower 6; A third condenser 20 is provided on the pipeline between the product light removal tower 6 and the third reflux tank 8, the bottom of the third reflux tank 8 is connected to the upper part of the product light removal tower 6 through a pipeline, the bottom of the third reflux tank 8 outputs the first product, and the upper part of the third reflux tank 8 is connected to the vacuum system; the bottom of the product light removal tower 6 is connected to the lower part of the product light removal tower 6 through a pipeline; a third heat exchanger 21 is provided on the pipeline between the bottom of the product light removal tower 6 and the lower part of the product light removal tower 6; a fourth condenser 22 is provided on the pipeline between the product refining tower 7 and the fourth reflux tank 9; the bottom of the fourth reflux tank 9 is connected to the upper part of the product refining tower 7 through a pipeline, the bottom of the fourth reflux tank 9 outputs the second product, and the upper part of the fourth reflux tank 9 is connected to the vacuum system; The bottom of the product refining tower 7 is connected to the bottom of the product refining tower 7 through a pipeline. A fourth heat exchanger 19 is provided on the pipeline between the bottom of the product refining tower 7 and the bottom of the product refining tower 7. The bottom of the product refining tower 7 is provided with a first heavy component output pipeline.

[0040] Reaction process: Ethylene oxide and monomethylamine enter the reaction process after mixing, and amination reaction occurs in the reactor 1. The reaction product enters the deamination process 4 from the top of the reactor, and part of the circulating material enters the reaction circulation heat collector 2. After cooling, the material enters the reaction circulation pump 3, and is sent back to the reactor after being pressurized by the reaction circulation pump.

[0041] There are two feed inlets below the reactor and one feed inlet at the bottom of the reactor; The operating pressure of the reactor is 4 MPaG and the operating temperature is 140°C; Two discharge ports are arranged at the middle and upper part of the reactor, and one discharge port is arranged at the top of the reactor.

[0042] The ratio of the material circulation amount of the other part of the top discharge of the reactor or the material drawn out from the side line after cooling to the reaction circulation amount of ethylene oxide and raw materials is 80.

[0043] Deamination process: the reaction product enters the deamination process 4, the material at the top of the deamination tower enters the first condenser 13 at the top of the tower, and enters the first reflux tank 14 after cooling. The material at the bottom of the tank is used to recover methylamine and is reused as a raw material to the reactor 1.

[0044] The operating pressure of the deamine tower is 0.4MPaG and the operating temperature is 140℃; Stabilizer A is water, and the injection rate is 500 kg / h.

[0045] Stabilizer B is monoethanolamine, and the injection rate is 5 kg / h.

[0046] Destabilizer A process: the reaction product enters the destabilizer A tower 5, the material at the top of the tower enters the second condenser 17 at the top of the tower, and after cooling, enters the second reflux tank 16. The bottom part of the material is stabilizer A and can be recycled.

[0047] The operating temperature of the destabilizer tower A is 45~135℃, and the operating pressure is 8~15KPaA.

[0048] Product light removal process: after demethylamine removal, the material enters the product light removal tower 6, the material at the top of the product light removal tower enters the third condenser 20 at the top of the tower, and after cooling, enters the third reflux tank 8, and part of the material at the bottom of the tank is sent out of the entire production unit as MMEA product (first product).

[0049] Stabilizer A enters the bottom of the deamine tower 4 after being accurately measured from the metering pump, and enters the subsequent destabilizer A process along with the reaction product.

[0050] Industrial verification has shown that the product of this project begins to thermally decompose at 130-140°C. The thermal decomposition rate is not high within 180°C, generally 1-5%. The thermal decomposition rate gradually increases around 200°C, and can be as high as 8-10%, causing serious product losses.

[0051] The operating pressure of the deamination process is 0.3~0.6MPaG, and reduced pressure operation cannot be used. Under this condition, the maximum operating temperature of the deamination process is 210℃. In order to reduce the operating temperature, the process technology of injecting stabilizer A is adopted, and the operating temperature can be reduced to within 150℃, thereby achieving the purpose of increasing the product yield.

[0052] Stabilizer B enters the bottom of the deamine tower 4 after being accurately measured from the metering pump, and then enters into the product and is sold together with the product.

[0053] The product of the present application is prone to problems such as excessive chromaticity. After industrial application, the addition of stabilizer B can effectively prevent the product chromaticity from exceeding the standard, thereby achieving the purpose of improving product stability.

[0054] The operating temperature of the product lightness removal tower 6 is 55~170℃, and the operating pressure is 3~14KPaA.

[0055] Product refining process: the material produced by the product light removal process enters the product refining tower 7, the material at the top of the product refining tower 7 enters the fourth condenser at the top of the tower, and enters the fourth reflux tank 9 after cooling. The material at the bottom of the tank is sent out of the entire production unit as the MDEA product (the second product), and the material at the bottom of the tower is sent out of the entire production unit as the heavy component.

[0056] The operating temperature of the product refining tower 7 is 130~170℃, and the operating pressure is 3~7KPaA.

[0057] The product of the lightness removal tower is methyl monoethanolamine (MMEA), and the parameters are shown in Table 1.

[0058] Table 1 Main process operating parameters Serial number Process Device Name Operation parameters 1 Reaction process Reactor 1 2 feeding ports 2 Reaction process Reaction cycle heat exchanger 2 Circulation ratio 80 3 Deamination process Deamine tower 4 Stabilizer A (water) injection rate 500 kg / h Stabilizer B (monoethanolamine) injection rate 5 kg / h According to the process flow of Implementation Case 1 and the operating parameters of Table 1, taking a 20,000 tons / year methylethanolamine unit as an example, the raw material conversion rate of the reaction process is 97%, and the annual processing cost is reduced by about 2 million yuan.

[0059] The reaction process produces 1.8t / h of low-pressure steam, reducing annual processing costs by approximately RMB 4 million.

[0060] The product yield of the deamination process has increased to about 96%. Taking a production capacity of 20,000 tons / year as an example, the annual economic benefit has increased by about 10 million yuan.

[0061] The present application sets up a multi-point feed of the reactor, and allows the raw materials ethylene oxide and methylamine to enter the reactor through multiple positions, so as to achieve the purpose of uniform distribution of raw materials and avoid local accumulation of raw materials, thereby improving the raw material conversion rate.

[0062] A heat extractor is set outside the reactor to remove the reaction heat in time to avoid reaction risks. The removed heat can be used to generate low-pressure steam, which can be used as heating steam for the reboiler of the distillation tower, saving the consumption of utility steam and achieving the purpose of reducing energy consumption.

[0063] The present application provides a means of injecting stabilizer A, which reduces the operating temperature of the deamination process from 210° C. to about 150° C., greatly reducing the decomposition rate of the product and achieving the purpose of increasing the product yield.

[0064] The present application provides a means of injecting stabilizer B, which can keep the chromaticity of the product continuously stable, thereby achieving the purpose of improving product stability.

[0065] Implementation Case 2: Compared with Implementation Case 1, the process flow of Implementation Case 2 does not change, only the operating parameters are changed, see Table 2.

[0066] Table 2 Main process operating parameters Serial number Process Device Name Operation parameters 1 Reaction process Reactor 1 4 feeding ports 2 Reaction process Reaction cycle heat exchanger 2 Circulation ratio 150 3 Deamination process Deamine tower 4 Stabilizer A (water) injection rate 700 kg / h Stabilizer B (monoethanolamine) injection rate 15 kg / h According to the process flow of Implementation Case 1 and the operating parameters of Table 2, taking a 20,000 tons / year methylethanolamine unit as an example, the raw material conversion rate of the reaction process is 98%, and the annual processing cost is reduced by about 3 million yuan.

[0067] The reaction process produces 2.3t / h of low-pressure steam, reducing annual processing costs by approximately RMB 5 million.

[0068] The product yield of the deamination process has increased to about 98%. Taking a production capacity of 20,000 tons / year as an example, the annual economic benefit has increased by about 16 million yuan.

[0069] Implementation Case 3: Compared with Implementation Case 1, the process flow of Implementation Case 3 does not change, only the operating parameters are changed, see Table 3.

[0070] Table 3 Main process operating parameters Serial number Process Device Name Operation parameters 1 Reaction process Reactor 1 5 feeding ports 2 Reaction process Reaction cycle heat exchanger 2 Circulation ratio 200 3 Deamination process Deamine tower 4 Stabilizer A (water) injection rate 900 kg / h Stabilizer B (monoethanolamine) injection rate 20 kg / h According to the process flow of Implementation Case 1 and the operating parameters of Table 3, taking a 20,000 tons / year methylethanolamine unit as an example, the raw material conversion rate of the reaction process is 99.9%, reducing the processing cost by approximately RMB 10 million per year.

[0071] The reaction process produces 2.7t / h of low-pressure steam, reducing annual processing costs by approximately RMB 6 million.

[0072] The product yield of the deamination process has increased to about 99%. Taking a production capacity of 20,000 tons / year as an example, the annual economic benefit has increased by about 20 million yuan.

[0073] Implementation Case 4: Compared with Implementation Case 1, the process flow of Implementation Case 4 does not change, and only the specific types of stabilizer A and stabilizer B are specified as n-hexane and monoethanolamine, respectively, as shown in Table 4.

[0074] Table 4 Main process operating parameters Serial number Process Device Name Operation parameters 1 Reaction process Reactor 1 2 feeding ports 2 Reaction process Reaction cycle heat exchanger 2 Circulation ratio 80 3 Deamination process Deamine tower 4 Stabilizer A (n-hexane) injection rate 500 kg / h Stabilizer B (monoethanolamine) injection rate 5 kg / h According to the process flow of Implementation Case 1 and the operating parameters of Table 4, taking a 20,000 tons / year methylethanolamine unit as an example, the product yield of the deamination process is increased to about 97.5%. Taking a 20,000 tons / year production capacity as an example, the annual economic benefit increases by about 13.3 million yuan.

[0075] Implementation Case 5: Compared with Implementation Case 4, the process flow of Implementation Case 5 does not change. Only the specific types of stabilizer A and stabilizer B are changed, namely water and diethanolamine, respectively, and the injection amount does not change, see Table 5.

[0076] Table 5 Main process operating parameters Serial number Process Device Name Operation parameters 1 Reaction process Reactor 1 2 feeding ports 2 Reaction process Reaction cycle heat exchanger 2 Circulation ratio 80 3 Deamination process Deamine tower 4 Stabilizer A (water) injection rate 500 kg / h Stabilizer B (diethanolamine) injection rate 5 kg / h According to the process flow of Implementation Case 4 and the operating parameters of Table 5, taking a 20,000 tons / year methylethanolamine unit as an example, the product yield of the deamination process is increased to about 97.9%. Taking a 20,000 tons / year production capacity as an example, the annual economic benefit increases by about 15 million yuan.

[0077] Implementation Case 6: Compared with Implementation Case 5, the process flow of Implementation Case 6 does not change, only the specific type of stabilizer B is changed, the type of stabilizer A does not change, and the injection amount does not change, see Table 6.

[0078] Table 6 Main process operating parameters Serial number Process Device Name Operation parameters 1 Reaction process Reactor 1 2 feeding ports 2 Reaction process Reaction cycle heat exchanger 2 Circulation ratio 80 3 Deamination process Deamine tower 4 Stabilizer A (water) injection rate 500kg / h Stabilizer B (triethanolamine) injection rate 5kg / h According to the process flow of Implementation Case 4 and the operating parameters of Table 6, taking the 20,000 tons / year methylethanolamine unit as an example, the product yield of the deamination process is increased to about 98.3%. Taking the 20,000 tons / year production capacity as an example, the annual economic benefit increases by about 17.2 million yuan.

[0079] Implementation Case 7: A device for preparing dimethylethanolamine comprises a reactor 1, an amine removal tower 4, a destabilizer A tower 5, a product light-removing tower 6, and a product refining tower 7; a raw material inlet pipe is provided at the bottom or below of the reactor 1; an ethylene oxide inlet pipe is provided at the bottom or below of the reactor 1; the top of the reactor 1 is connected with the middle of the amine removal tower 4, the bottom of the amine removal tower 4 is connected with the destabilizer A tower 5, and the bottom of the destabilizer A tower 5 is connected with the middle of the product light-removing tower 6; if the raw material is dimethylamine, the first product is dimethylethanolamine.

[0080] A first valve 10 is provided on both the raw material inlet pipe and the ethylene oxide inlet pipe; the top of the reactor 1 is connected to the middle of the deamine tower 4 through a pipeline, and the top of the reactor 1 is connected to the first branch pipe and the second branch pipe respectively through a reflux pipeline; the first branch pipe is connected to the upper part of the reactor 1; the second branch pipe is connected to the bottom of the reactor 1, a second valve 11 is provided on the reflux pipeline, and a third valve 12 is provided on the first branch pipe; a reaction cycle heat collector 2 and a reaction cycle pump 3 are provided on the second branch pipe in sequence.

[0081] The top of the deamine tower 4 is connected to the first reflux tank 14 through a pipeline, and a first condenser 13 is provided on the pipeline between the first reflux tank 14 and the deamine tower 4; the bottom of the first reflux tank 14 is connected to the upper part of the deamine tower 4 through a pipeline, and the bottom of the first reflux tank 14 is connected to the raw material inlet pipe through a pipeline; the lower part of the deamine tower 4 is provided with a stabilizer A inlet pipeline and a first stabilizer B inlet pipeline; The bottom of the deamine tower 4 is connected to the middle of the destabilizer A tower 5 through a pipeline; the bottom of the deamine tower 4 is connected to the bottom of the deamine tower 4 through a pipeline, and a first heat exchanger 15 is provided on the pipeline connecting the bottom of the deamine tower 4 and the bottom of the deamine tower 4; The top of the destabilizer A tower 5 is connected to the second reflux tank 16 through a pipeline; a second condenser 17 is provided on the pipeline between the deamine tower 4 and the second reflux tank 16; the bottom of the destabilizer A tower 5 is connected to the middle of the product light removal tower 6 through a pipeline, the bottom of the second reflux tank 16 is connected to the top of the destabilizer A tower 5 through a pipeline, and the bottom of the second reflux tank 16 outputs stabilizer A through a pipeline; the bottom of the destabilizer A tower 5 is connected to the bottom of the destabilizer A tower 5 through a pipeline, and a second heat exchanger 18 is provided on the pipeline between the bottom of the destabilizer A tower 5 and the bottom of the destabilizer A tower 5, and a second stabilizer B inlet pipeline is provided at the bottom of the product light removal tower 6.

[0082] A third condenser 20 is provided on the pipeline between the product de-lightening tower 6 and the third reflux tank 8, the bottom of the third reflux tank 8 is connected to the upper part of the product de-lightening tower 6 through a pipeline, the bottom of the third reflux tank 8 outputs the first product, and the upper part of the third reflux tank 8 is connected to the vacuum system; the bottom of the product de-lightening tower 6 is connected to the bottom of the product de-lightening tower 6 through a pipeline; a third heat exchanger 21 is provided on the pipeline between the bottom of the product de-lightening tower 6 and the bottom of the product de-lightening tower 6, and a second heavy component output pipeline is provided at the bottom of the product de-lightening tower 6.

[0083] Reaction process: Ethylene oxide and dimethylamine are mixed and then enter the reaction process. Amination reaction occurs in the reactor 1. The reaction product enters the deamination process 4 from the top of the reactor. Part of the circulating material enters the reaction circulation heat extractor 2. After cooling, the material enters the reaction circulation pump 3 and is returned to the reactor after being pressurized by the reaction circulation pump.

[0084] There are two feed inlets below the reactor and one feed inlet at the bottom of the reactor; The operating pressure of the reactor is 4 MPaG and the operating temperature is 140°C; Two discharge ports are arranged at the middle and upper part of the reactor, and one discharge port is arranged at the top of the reactor.

[0085] The ratio of the material circulation amount of the other part of the top discharge of the reactor or the material drawn out from the side line after cooling to the reaction circulation amount of ethylene oxide and raw materials is 80.

[0086] Deamination process: the reaction product enters the deamination process 4, the material at the top of the deamination tower enters the first condenser 13 at the top of the tower, and enters the first reflux tank 14 after cooling. The material at the bottom of the tank is used to recover methylamine and is reused as a raw material to the reactor 1.

[0087] The operating pressure of the deamine tower is 0.4MPaG and the operating temperature is 160℃; Stabilizer A is water, and the injection rate is 500 kg / h.

[0088] Stabilizer B is monoethanolamine, and the injection rate is 5 kg / h.

[0089] Destabilizer A process: the reaction product enters the destabilizer A tower 5, the material at the top of the tower enters the second condenser 17 at the top of the tower, and after cooling, enters the second reflux tank 16. The bottom part of the material is stabilizer A and can be recycled.

[0090] The operating temperature of the destabilizer tower A is 45~135℃, and the operating pressure is 8~15KPaA.

[0091] Product light removal process: after demethylamine removal, the material enters the product light removal tower 6, the material at the top of the product light removal tower enters the third condenser 20 at the top of the tower, and after cooling, enters the third reflux tank 8, and part of the material at the bottom of the tank is sent out of the entire production unit as DMEA product.

[0092] The operating temperature of the product lightness removal tower 6 is 60~110℃, the operating pressure is 3~7KPaA, and the operating parameters are shown in Table 7.

[0093] Table 7 Main process operating parameters Serial number Process Device Name Operation parameters 1 Reaction process Reactor 1 2 feeding ports 2 Reaction process Reaction cycle heat exchanger 2 Circulation ratio 80 3 Deamination process Deamine tower 4 Stabilizer A (water) injection rate 500 kg / h Stabilizer B (monoethanolamine) injection rate 5 kg / h According to the process flow of Implementation Case 1 and the operating parameters of Table 1, taking a 20,000 tons / year methylethanolamine unit as an example, the raw material conversion rate of the reaction process is 97%, and the annual processing cost is reduced by about 2 million yuan.

[0094] The reaction process produces 1.8t / h of low-pressure steam, reducing annual processing costs by approximately RMB 4 million.

[0095] The product yield of the deamination process has increased to about 96%. Taking a production capacity of 20,000 tons / year as an example, the annual economic benefit has increased by about 10 million yuan.

[0096] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing methyl monoethanolamine and methyl diethanolamine or dimethylethanolamine, characterized in that: The steps include: Ethylene oxide and raw materials react in the reactor, and part of the discharge from the top of the reactor enters the middle of the downstream deamine tower; the other part of the discharge from the top of the reactor or the material drawn out from the side line is cooled and circulated back to the bottom of the reactor; Stabilizer A and stabilizer B are introduced below the deamine tower, the material obtained at the bottom of the deamine tower is sequentially introduced into the middle of the destabilizer A tower, the material obtained at the bottom of the destabilizer A tower is introduced into the middle of the product light-removing tower, and the top of the product light-removing tower is condensed to obtain the first product; If the raw material is monomethylamine, the first product is methyl monoethanolamine, the material obtained at the bottom of the product light removal tower enters the product refining tower, and the second product is methyl diethanolamine at the top of the product refining tower; If the raw material is dimethylamine, the first product is dimethylethanolamine.

2. The method for preparing methyl monoethanolamine and methyl diethanolamine or dimethylethanolamine according to claim 1, characterized in that: Several feed ports are provided below and at the bottom of the reactor; ethylene oxide and raw materials enter the reactor through the feed ports; Preferably, 1 to 15 feed inlets are provided below the reactor, and 1 feed inlet is provided at the bottom of the reactor; And / or, a plurality of discharge ports are provided below and at the bottom of the reactor; Preferably, 1 to 10 discharge ports are provided in the upper middle portion of the reactor, and 1 discharge port is provided at the top of the reactor.

3. The method for preparing methyl monoethanolamine and methyl diethanolamine or dimethylethanolamine according to claim 1, characterized in that: The operating pressure of the reactor is 3.0~5.5MPaG, and the operating temperature is 100~200℃.

4. The method for preparing methyl monoethanolamine and methyl diethanolamine or dimethylethanolamine according to claim 1, characterized in that: The reaction circulation ratio of the material circulation amount of the other part of the top discharge of the reactor or the material drawn out from the side line after cooling to the sum of ethylene oxide and raw materials is 50~500.

5. The method for preparing methyl monoethanolamine and methyl diethanolamine or dimethylethanolamine according to claim 1, characterized in that: The operating pressure of the deamine tower is 0.3~0.6MPaG, and the operating temperature is 130~150℃; And / or, the stabilizer A includes one or more of water, n-hexane, isohexane, cyclohexane, n-heptane, isoheptane, n-octane or isooctane, and the injection amount of the stabilizer A is 1.0% to 50.0% of the product output; And / or, stabilizer B includes one or more of monoethanolamine, diethanolamine, triethanolamine, monoethylhydroxylamine, diethylhydroxylamine, and triethylhydroxylamine, and the injection amount of stabilizer B is 0.001% to 1.0% of the product output.

6. The method for preparing methyl monoethanolamine and methyl diethanolamine or dimethylethanolamine according to claim 1, characterized in that: The top material of the deamine tower is condensed and then circulated back to the interior of the deamine tower or enters the reactor as a raw material; And / or, the material obtained at the bottom of the deamine tower enters the middle of the destabilizer A tower, and the material at the top of the tower is cooled to obtain stabilizer A or enters the destabilizer A tower; And / or, the operating temperature of the destabilizer tower A is 42~150°C and the operating pressure is 5~20KPaA; And / or, the material obtained at the bottom of the destabilizer A tower enters the middle of the product light-removal tower, stabilizer B is introduced to the bottom of the product light-removal tower, and the top material of the product light-removal tower enters the condensation to obtain the product or refluxes into the product light-removal tower; And / or, the operating temperature of the product lightness removal tower is 55~180℃, and the operating pressure is 2~20KPaA; And / or, the operating temperature of the product refining tower is 100~180℃, and the operating pressure is 2~10KPaA; And / or, if the raw material is monomethylamine, the material obtained at the bottom of the product light removal tower enters the middle of the product refining tower, and the top material of the product refining tower is condensed to obtain the first product or refluxed into the refining tower; the bottom material of the product light removal tower is the heavy component; And / or, if the raw material is dimethylamine, the heavy components are output from the bottom of the product lightness removal tower.

7. The device used in the method for preparing methylmonoethanolamine and methyldiethanolamine or dimethylethanolamine according to any one of claims 1 to 6, characterized in that: It includes reactor, amine removal tower, stabilizer A removal tower, product light removal tower, and product refining tower; A raw material inlet pipe is provided at the bottom or below of the reactor; An ethylene oxide inlet pipe is provided at the bottom or below of the reactor; The top of the reactor is connected to the middle of the deamine tower, the bottom of the deamine tower is connected to the destabilizer A tower, and the bottom of the destabilizer A tower is connected to the middle of the product light-removal tower; If the raw material is monomethylamine, the output material from the top of the product light-removing tower is cooled and then output as the first product; the bottom of the product light-removing tower is connected to the middle of the product refining tower; the output material from the top of the product refining tower is cooled and then output as the second product; If the raw material is dimethylamine, the material output from the top of the product light-removal tower is cooled and then output as the first product, and the heavy component is output from the bottom of the product light-removal tower.

8. The device according to claim 7, characterized in that: The raw material inlet pipe and the ethylene oxide inlet pipe are both provided with a first valve; And / or, the top of the reactor is connected to the middle of the deamine tower through a pipeline, and the top of the reactor is connected to the first branch pipe and the second branch pipe respectively through a reflux pipeline; the first branch pipe is connected to the upper part of the reactor; the second branch pipe is connected to the bottom of the reactor; And / or, a second valve is provided on the return pipe; And / or, a third valve is provided on the first branch pipe; And / or, a reaction circulation heat collector and a reaction circulation pump are sequentially arranged on the second branch pipe.

9. The device according to claim 7, characterized in that: The top of the deamine tower is connected to the first reflux tank through a pipeline, and a first condenser is provided on the pipeline between the first reflux tank and the deamine tower; the bottom of the first reflux tank is connected to the upper part of the deamine tower through a pipeline, and the bottom of the first reflux tank is connected to the raw material inlet pipe through a pipeline; A stabilizer inlet A pipeline and a first stabilizer inlet B pipeline are respectively provided below the deamine tower; And / or, the bottom of the deamine tower is connected to the middle of the destabilizer A tower through a pipeline; the bottom of the deamine tower is connected to the bottom of the deamine tower through a pipeline, and a first heat exchanger is provided on the pipeline connecting the bottom of the deamine tower and the bottom of the deamine tower; And / or, the top of the destabilizer tower A is connected to the second reflux tank through a pipeline; a second condenser is provided on the pipeline between the deamine tower and the second reflux tank; the bottom of the destabilizer tower A is connected to the middle of the product light removal tower through a pipeline; And / or, the bottom of the second reflux tank is connected to the top of the destabilizer A tower through a pipeline, and the bottom of the second reflux tank outputs stabilizer A through the pipeline; And / or, the bottom of the destabilizer tower A is connected to the bottom of the destabilizer tower A through a pipeline, and a second heat exchanger is provided on the pipeline between the bottom of the destabilizer tower A and the bottom of the destabilizer tower A.

10. The device according to claim 7, characterized in that: A second stabilizer B pipeline is provided below the product lightness removal tower; And / or, a third condenser is provided on the pipeline between the product light removal tower and the third reflux tank, the bottom of the third reflux tank is connected to the upper part of the product light removal tower through a pipeline, the bottom of the third reflux tank outputs the first product, and the upper part of the third reflux tank is connected to the vacuum system; And / or, the bottom of the product lightness removal tower is connected to the bottom of the product lightness removal tower through a pipeline; a third heat exchanger is provided on the pipeline between the bottom of the product lightness removal tower and the bottom of the product lightness removal tower; And / or, a fourth condenser is provided on the pipeline between the product refining tower and the fourth reflux tank; the bottom of the fourth reflux tank is connected to the upper part of the product refining tower through a pipeline, the bottom of the fourth reflux tank outputs the second product, and the upper part of the fourth reflux tank is connected to the vacuum system; And / or, the bottom of the product refining tower is connected to the bottom of the product refining tower through a pipeline, and a fourth heat exchanger is provided on the pipeline between the bottom of the product refining tower and the bottom of the product refining tower; And / or, if the product is monomethylamine, a first heavy component output pipeline is provided at the bottom of the product refining tower; If the product is dimethylamine, a second heavy component output pipeline is provided at the bottom of the product light component removal tower.

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