Production device for preparing hydroxypivalaldehyde, an intermediate of neopentyl glycol

Abstract

The utility model belongs to the technical field of compound preparation, and specifically relates to a production device for preparing hydroxypivalaldehyde, an intermediate of neopentyl glycol, comprising a condensation reactor 1 and a condensation reactor 2, wherein the bottom of the condensation reactor 1 is connected to the top of the condensation reactor 2, the bottom of the condensation reactor 1 is connected to a heat exchanger 1, and the bottom of the condensation reactor 2 is connected to a heat exchanger 2; the condensation reactor 1 is connected to a methanol oxidation system, and the condensation reactor 2 is connected to a product distillation system. The utility model can realize continuous production of hydroxypivalaldehyde, improve the conversion rate of raw materials, reduce the generation of side reaction products, and reduce the emission of pollutants; the high-temperature steam generated in the production process can be recycled to reduce resource waste; the combination of the condensation reactor 1 and the condensation reactor 2 can effectively improve the yield and purity of the pivaloyl chloride product and increase the reaction rate.

Description

Technical Field

[0001] The utility model belongs to the technical field of compound preparation, and specifically relates to a production device for preparing hydroxypivalaldehyde, an intermediate of neopentyl glycol. Background Art

[0002] Neopentyl glycol is an important chemical raw material, which is widely used in polyurethane, plastics, coatings and other fields. Hydroxypivalaldehyde is an important intermediate in the production process of neopentyl glycol. In the current production process, hydroxypivalaldehyde is usually prepared by condensation method, and is produced by batch reaction device. Ordinary batch reaction device is easy to cause uneven mixing of materials and reduced reaction yield.

[0003] Chinese patent CN111620767A discloses a method for improving the selectivity of aldol condensation reaction, wherein the aqueous solution of C1-C5 aldehyde and alkaline compound participating in the reaction is introduced into a coil reactor in a cocurrent manner, the aqueous solution of the alkaline compound forms a continuous phase under turbulent conditions, and the C1-C5 aldehyde is dispersed in the continuous phase in the form of droplets. The C1-C5 aldehyde is selected from one or two of formaldehyde, acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, n-valeraldehyde, and isovaleraldehyde; the alkaline compound is selected from at least one of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, ammonia water, trimethylamine, triethylamine, and diisopropylamine. At the same time, it provides the preparation of 1,3-butanediol by condensation of acetaldehyde and inorganic alkaline compounds and the preparation of hydroxy-pivalaldehyde by condensation of formaldehyde, isobutyraldehyde and trimethylamine aqueous solution.

[0004] This patent can improve the mixing degree of materials, but there are problems such as long production cycle, easy corrosion of equipment by solution, need for separation, complex operation and low product yield. Utility Model Content

[0005] In view of the above deficiencies in the prior art, the technical problem to be solved by the utility model is to provide a production device for preparing hydroxypivalaldehyde, an intermediate of neopentyl glycol, which can realize continuous production, improve the reaction rate, and fully utilize the materials.

[0006] The technical solution adopted by the utility model to solve its technical problems is:

[0007] The production device for preparing hydroxypivalaldehyde, an intermediate of neopentyl glycol, comprises a condensation reactor 1 and a condensation reactor 2, wherein the bottom of the condensation reactor 1 is connected to the top of the condensation reactor 2, the bottom of the condensation reactor 1 is connected to a heat exchanger 1, and the bottom of the condensation reactor 2 is connected to a heat exchanger 2;

[0008] The condensation reactor 1 is connected to a methanol oxidation system, which includes an oxidation reactor, a tube cooler is connected to the oxidation reactor, a mixing reactor is connected to the upper part of the oxidation reactor, a methanol pipeline and an air pipeline are respectively arranged in the middle and lower parts of the mixing reactor, a steam pipeline and a steam recovery pipeline are arranged on the top of the tube cooler, the steam recovery pipeline is connected to the mixing reactor, an absorption tower 1 is connected to the lower part of the oxidation reactor, a lower part of the absorption tower is connected to the bottom of the condensation reactor 1, an isobutyraldehyde pipeline and a trimethylamine pipeline are respectively arranged at the bottom of the condensation reactor 1, an absorption tower 2 is connected to the upper part of the absorption tower 1, a tail gas pipeline 1 is arranged on the top of the absorption tower 2, and a desalted water pipeline is arranged on the upper part of the absorption tower 2;

[0009] The condensation reactor 2 is connected to a product distillation system, which includes a distillation tower. The top of the condensation reactor 1 and the top of the condensation reactor 2 are both connected to the upper part of the distillation tower, the bottom of the condensation reactor 2 is connected to the upper part of the distillation tower, the top of the distillation tower is connected to a top heat exchanger, the outlet of the top heat exchanger is connected to the top of the condensation reactor 1, the top of the top heat exchanger is provided with an exhaust gas pipeline 2, the bottom of the distillation tower is respectively connected to a reboiler heat exchanger and a heat exchanger 3, and the outlet of the heat exchanger 3 is connected to a storage tank.

[0010] in:

[0011] The upper part of the oxidation reactor is provided with a cooling pipe 1 connected to the inlet of the tube cooler, and the middle part of the oxidation reactor is provided with a cooling pipe 2 connected to the outlet of the tube cooler.

[0012] The lower part of the oxidation reactor is provided with an oxidation pipeline, which is connected to the lower part of the absorption tower, and the lower part of the absorption tower is connected to the condensation reactor through a discharge pipeline one.

[0013] The top of the absorption tower 1 is provided with an absorption pipe 1, which is connected to the lower inlet of the absorption tower 2. The middle of the absorption tower 1 is provided with an absorption pipe 2, which is connected to the lower outlet of the absorption tower 2. An absorption pump is arranged on the absorption pipe 2.

[0014] The discharge pipe 1 is connected to the bottom inlet of the condensation reactor 1, and a discharge pump is arranged on the discharge pipe 1.

[0015] The condensation reactor 1 is connected to the condensation reactor 2 through a transmission pipeline, the top of the condensation reactor 1 and the top of the condensation reactor 2 are both connected to the upper part of the distillation tower through a gas pipeline, and the bottom of the condensation reactor 2 is connected to the upper part of the distillation tower through a discharge pipeline 2.

[0016] A material pump 1 is arranged on the pipeline connected to the bottom outlet of the condensation reactor 1, and a material pump 2 is arranged on the pipeline connected to the bottom outlet of the condensation reactor 2.

[0017] The bottom outlet of the condensation reactor 1 is connected to the inlet of the heat exchanger 1, and the outlet of the heat exchanger 1 is connected to the bottom inlet of the condensation reactor 1; the bottom outlet of the condensation reactor 2 is connected to the inlet of the heat exchanger 2, and the outlet of the heat exchanger 2 is connected to the bottom inlet of the condensation reactor 2.

[0018] The bottom of the distillation tower is connected to the reboiling heat exchanger and the heat exchanger three through the bottom pipeline, and a material pump three is arranged on the bottom pipeline; the bottom outlet of the distillation tower is connected to the inlet of the reboiling heat exchanger, and the outlet of the reboiling heat exchanger is connected to the lower inlet of the distillation tower.

[0019] The outlet of the tower top heat exchanger is connected to the condensation reactor one through a circulation pipeline, and a material pump four is arranged on the circulation pipeline; the top outlet of the distillation tower is connected to the inlet of the tower top heat exchanger, and the outlet of the tower top heat exchanger is connected to the upper inlet of the distillation tower.

[0020] The beneficial effects of the utility model are:

[0021] The utility model can realize continuous production of hydroxypivalaldehyde, improve raw material conversion rate, reduce the generation of side reaction products, and reduce pollutant emissions; the high-temperature steam generated in the production process can be recycled to reduce resource waste; the combination of the first condensation reactor and the second condensation reactor can effectively improve the yield and purity of the pivaloyl chloride product and increase the reaction rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the structure of the utility model.

[0023] In the figure: 1, mixing reactor; 2, oxidation reactor; 3, absorption tower 1; 4, shell and tube cooler; 5, absorption tower 2; 6, discharge pump; 7, absorption pump; 8, condensation reactor 1; 9, heat exchanger 1; 10, heat exchanger 2; 11, condensation reactor 2; 12, distillation tower; 13, reboiling heat exchanger; 14, heat exchanger 3; 15, tower top heat exchanger; 16, storage tank; 17, material pump 3; 18, material pump 2; 19, material pump 1; 20, material pump 4; 101, methanol pipeline; 102, air pipeline; 10 3. Steam recovery pipeline; 201. Cooling pipeline 2; 301. Oxidation pipeline; 302. Absorption pipeline 2; 401. Cooling pipeline 1; 402. Steam pipeline; 501. Desalted water pipeline; 502. Tail gas pipeline 1; 503. Absorption pipeline 1; 801. Discharge pipeline 1; 802. Isobutyraldehyde pipeline; 803. Trimethylamine pipeline; 1101. Transmission pipeline; 1201. Gas pipeline; 1202. Discharge pipeline 2; 1301. Tower bottom pipeline; 1501. Circulation pipeline; 1502. Tail gas pipeline 2. DETAILED DESCRIPTION

[0024] The embodiments of the present utility model are further described below in conjunction with the accompanying drawings.

[0025] Example 1

[0026] like Figure 1 As shown, the production device for preparing hydroxypivalaldehyde, an intermediate of neopentyl glycol, described in the utility model comprises a condensation reactor 1 8 and a condensation reactor 2 11, the bottom of the condensation reactor 1 8 is connected to the top of the condensation reactor 2 11, the bottom of the condensation reactor 1 8 is connected to a heat exchanger 1 9, and the bottom of the condensation reactor 2 11 is connected to a heat exchanger 2 10;

[0027] The condensation reactor 8 is connected to a methanol oxidation system, which includes an oxidation reactor 2, a tube cooler 4 is connected to the oxidation reactor 2, a mixing reactor 1 is connected to the upper part of the oxidation reactor 2, a methanol pipeline 101 and an air pipeline 102 are respectively arranged in the middle and lower parts of the mixing reactor 1, a steam pipeline 402 and a steam recovery pipeline 103 are arranged on the top of the tube cooler 4, and the steam recovery pipeline 103 is connected to the mixing reactor 1, the lower part of the oxidation reactor 2 is connected to an absorption tower 3, the lower part of the absorption tower 3 is connected to the bottom of the condensation reactor 8, an isobutyraldehyde pipeline 802 and a trimethylamine pipeline 803 are respectively arranged at the bottom of the condensation reactor 8, the absorption tower 3 is connected to the absorption tower 25, a tail gas pipeline 1502 is arranged on the top of the absorption tower 25, and a desalted water pipeline 501 is arranged on the upper part of the absorption tower 25;

[0028] The condensation reactor 11 is connected to a product distillation system, which includes a distillation tower 12. The top of the condensation reactor 18 and the top of the condensation reactor 11 are both connected to the upper part of the distillation tower 12, the bottom of the condensation reactor 11 is connected to the upper part of the distillation tower 12, the top of the distillation tower 12 is connected to a top heat exchanger 15, the outlet of the top heat exchanger 15 is connected to the top of the condensation reactor 18, the top of the top heat exchanger 15 is provided with an exhaust gas pipeline 1502, the bottom of the distillation tower 12 is respectively connected to a reboiler heat exchanger 13 and a heat exchanger 3 14, and the outlet of the heat exchanger 3 14 is connected to a storage tank 16.

[0029] A portion of the steam generated inside the tube cooler 4 is transported back to the mixing reactor 1 for methanol oxidation, and the other portion is transported to the reboiler heat exchanger 13 through the steam pipe 402 for heating the material in the reboiler heat exchanger 13 .

[0030] The tail gas in tail gas pipeline 1 502 and tail gas pipeline 2 1502 is uniformly transported to the incineration process to be incinerated into CO2 and other substances, thereby reducing the emission of pollutants.

[0031] A cooling pipe 1 401 is arranged at the upper part of the oxidation reactor 2, and the cooling pipe 1 401 is connected to the inlet of the shell and tube cooler 4. A cooling pipe 201 is arranged at the middle part of the oxidation reactor 2, and the cooling pipe 201 is connected to the outlet of the shell and tube cooler 4.

[0032] An oxidation pipeline 301 is provided at the lower part of the oxidation reactor 2, and the oxidation pipeline 301 is connected to the lower part of the absorption tower 3, and the lower part of the absorption tower 3 is connected to the condensation reactor 8 through a discharge pipeline 801.

[0033] An absorption pipe 1503 is arranged at the top of absorption tower 13, and absorption pipe 1503 is connected to the lower inlet of absorption tower 25. An absorption pipe 2302 is arranged in the middle of absorption tower 13, and absorption pipe 2302 is connected to the lower outlet of absorption tower 25. An absorption pump 7 is arranged on absorption pipe 2302.

[0034] The combined use of absorption tower 1 3 and absorption tower 2 5 can increase the absorption rate of formaldehyde and reduce the loss of formaldehyde.

[0035] The discharge pipeline 801 is connected to the bottom inlet of the condensation reactor 8, and a discharge pump 6 is provided on the discharge pipeline 801.

[0036] The condensation reactor 18 is connected to the condensation reactor 2 11 through the transmission pipeline 1101, the top of the condensation reactor 18 and the top of the condensation reactor 2 11 are connected to the upper part of the distillation tower 12 through the gas pipeline 1201, and the bottom of the condensation reactor 2 11 is connected to the upper part of the distillation tower 12 through the discharge pipeline 2 1202.

[0037] The bottom inlets of the condensation reactor 1 8 and the condensation reactor 2 13 are both provided with ejectors.

[0038] A material pump 19 is provided on the pipeline connected to the bottom outlet of the condensation reactor 1 8 , and a material pump 2 18 is provided on the pipeline connected to the bottom outlet of the condensation reactor 2 11 .

[0039] The bottom outlet of condensation reactor 8 is connected to the inlet of heat exchanger 9, and the outlet of heat exchanger 9 is connected to the bottom inlet of condensation reactor 8; the bottom outlet of condensation reactor 2 11 is connected to the inlet of heat exchanger 2 10, and the outlet of heat exchanger 2 10 is connected to the bottom inlet of condensation reactor 2 11.

[0040] The cooling medium inside heat exchanger 1 9 and heat exchanger 2 10 is hot water at 50-60° C. to ensure the stability of the condensation reaction.

[0041] The bottom of the distillation tower 12 is connected to the reboiling heat exchanger 13 and the heat exchanger 14 respectively through the bottom pipeline 1301, and a material pump 17 is arranged on the bottom pipeline 1301; the bottom outlet of the distillation tower 12 is connected to the inlet of the reboiling heat exchanger 13, and the outlet of the reboiling heat exchanger 13 is connected to the lower inlet of the distillation tower 12.

[0042] The outlet of the top heat exchanger 15 is connected to the condensation reactor 8 through a circulation pipeline 1501, and a material pump 20 is arranged on the circulation pipeline 1501; the top outlet of the distillation tower 12 is connected to the inlet of the top heat exchanger 15, and the outlet of the top heat exchanger 15 is connected to the upper inlet of the distillation tower 12.

[0043] Working principle and process:

[0044] When preparing hydroxypivalaldehyde, methanol and air are transported to a mixing reactor 1 in proportion, evaporated at a temperature of 45-49° C. and a pressure of 10-15KPa, and the evaporated binary gas is mixed with water vapor to prepare a methanol-water vapor-air ternary gas. The ternary gas enters from the top of the oxidation reactor 2 and passes through the inside of the oxidation reactor 2 from top to bottom to complete the oxidation reaction to obtain formaldehyde gas, and the reaction temperature in the oxidation reactor 2 is controlled to be 630-660° C.; the formaldehyde gas enters the tube cooler 4 for cooling, and a large amount of steam is generated during cooling. The cooled formaldehyde is transported back to the oxidation reactor 2, and the formaldehyde in the oxidation reactor 2 is uniformly transported to the absorption tower 1 3 for absorption. Part of the formaldehyde will flow from the absorption tower 1 3 to the absorption tower 2 5, and desalted water is added to the top of the absorption tower 2 5 to spray and absorb the formaldehyde. The desalted water at the bottom of the absorption tower 2 5 is then transported to the absorption tower 1 3 to spray and absorb the formaldehyde to obtain a formaldehyde solution, and the unabsorbed tail gas is recovered through the tail gas pipeline 1 502 at the top of the absorption tower 2 5;

[0045] The formaldehyde solution is transported to the interior of the condensation reactor 8, and isobutylaldehyde with a purity of 99.5% and trimethylamine with a purity of 99.9% are added in corresponding proportions, and a primary condensation reaction is carried out in the condensation reactor 8; the material in the condensation reactor 8 is extracted by a material pump 19, and after cooling by a heat exchanger 9, it is recirculated into the condensation reactor 8 for sufficient reaction; the material after the primary condensation reaction is transported to the condensation reactor 2 11 through a material pump 19 for a secondary condensation reaction to generate hydroxypivalaldehyde, the material in the condensation reactor 2 11 is extracted by a material pump 2 18, and after cooling by a heat exchanger 2 10, it is recirculated into the condensation reactor 2 11 for sufficient reaction, and the gas in the condensation reactor 8 and the condensation reactor 2 11 is transported to the distillation tower 12 for distillation;

[0046] The hydroxypivalaldehyde material in the condensation reactor 11 is transported to the upper part of the distillation tower 12 for distillation. The pressure in the distillation tower 12 is 15-20KPa. The top distillate includes water, formic acid, trimethylamine, isobutylaldehyde and some side reaction products. After the distillate is cooled by the top heat exchanger 15, it is transported back to the condensation reactor 8 and the distillation tower 12 by the material pump 20 for re-reaction, and the remaining tail gas is recovered through the tail gas pipeline 1502; the material at the bottom of the distillation tower 12 is an aqueous solution with hydroxypivalaldehyde as the main substance. The material pump 3 17 can transport the material to the reboiling heat exchanger 13, and then increase the temperature and transport it back to the distillation tower 12 for distillation. The hydroxypivalaldehyde solution obtained by distillation is transported to the heat exchanger 3 14 by the material pump 3 17 for cooling, and the hydroxypivalaldehyde solution after the heat exchanger 3 14 is transported to the storage tank 16 for storage.

Claims

1. A production device for preparing hydroxypivalaldehyde as an intermediate of neopentyl glycol, comprising a condensation reactor 1 (8) and a condensation reactor 2 (11), characterized in that: The bottom of the condensation reactor 1 (8) is connected to the top of the condensation reactor 2 (11), the bottom of the condensation reactor 1 (8) is connected to the heat exchanger 1 (9), and the bottom of the condensation reactor 2 (11) is connected to the heat exchanger 2 (10); The condensation reactor (8) is connected to a methanol oxidation system, the methanol oxidation system comprising an oxidation reactor (2), the oxidation reactor (2) being connected to a tube cooler (4), the upper part of the oxidation reactor (2) being connected to a mixing reactor (1), the middle part and the lower part of the mixing reactor (1) being provided with a methanol pipeline (101) and an air pipeline (102), respectively, the top of the tube cooler (4) being provided with a steam pipeline (402) and a steam recovery pipeline (103), the steam recovery pipeline (103) being connected to the mixing reactor (1), the lower part of the oxidation reactor (2) being connected to an absorption tower (3), the lower part of the absorption tower (3) being connected to the bottom of the condensation reactor (8), the bottom of the condensation reactor (8) being provided with an isobutylaldehyde pipeline (802) and a trimethylamine pipeline (803), respectively, the upper part of the absorption tower (3) being connected to an absorption tower (5), the top of the absorption tower (5) being provided with an exhaust gas pipeline (1) (502), and the upper part of the absorption tower (5) being provided with a desalted water pipeline (501); The second condensation reactor (11) is connected to a product distillation system, which comprises a distillation tower (12). The top of the first condensation reactor (8) and the top of the second condensation reactor (11) are both connected to the upper part of the distillation tower (12). The bottom of the second condensation reactor (11) is connected to the upper part of the distillation tower (12). The top of the distillation tower (12) is connected to a tower top heat exchanger (15). The outlet of the tower top heat exchanger (15) is connected to the top of the first condensation reactor (8). The top of the tower top heat exchanger (15) is provided with a second tail gas pipeline (1502). The bottom of the distillation tower (12) is respectively connected to a reboiler heat exchanger (13) and a third heat exchanger (14). The outlet of the third heat exchanger (14) is connected to a storage tank (16).

2. The production device for preparing hydroxypivalaldehyde as an intermediate of neopentyl glycol according to claim 1, characterized in that: A cooling pipe 1 (401) is provided at the upper part of the oxidation reactor (2), and the cooling pipe 1 (401) is connected to the inlet of the shell and tube cooler (4). A cooling pipe 2 (201) is provided at the middle part of the oxidation reactor (2), and the cooling pipe 2 (201) is connected to the outlet of the shell and tube cooler (4).

3. The production device for preparing hydroxypivalaldehyde as an intermediate of neopentyl glycol according to claim 1, characterized in that: An oxidation pipeline (301) is provided at the lower part of the oxidation reactor (2), and the oxidation pipeline (301) is connected to the lower part of the absorption tower (3), and the lower part of the absorption tower (3) is connected to the condensation reactor (8) via the discharge pipeline (801).

4. The production device for preparing hydroxypivalaldehyde as an intermediate of neopentyl glycol according to claim 1, characterized in that: An absorption pipe 1 (503) is arranged at the top of the absorption tower 1 (3), and the absorption pipe 1 (503) is connected to the lower inlet of the absorption tower 2 (5). An absorption pipe 2 (302) is arranged in the middle of the absorption tower 1 (3), and the absorption pipe 2 (302) is connected to the lower outlet of the absorption tower 2 (5). An absorption pump (7) is arranged on the absorption pipe 2 (302).

5. The production device for preparing hydroxypivalaldehyde as an intermediate of neopentyl glycol according to claim 3, characterized in that: The discharge pipe 1 (801) is connected to the bottom inlet of the condensation reactor 1 (8), and a discharge pump (6) is provided on the discharge pipe 1 (801).

6. The production device for preparing hydroxypivalaldehyde as an intermediate of neopentyl glycol according to claim 1, characterized in that: The condensation reactor 1 (8) is connected to the condensation reactor 2 (11) via a transfer pipeline (1101); the top of the condensation reactor 1 (8) and the top of the condensation reactor 2 (11) are both connected to the upper part of the distillation tower (12) via a gas pipeline (1201); and the bottom of the condensation reactor 2 (11) is connected to the upper part of the distillation tower (12) via a discharge pipeline 2 (1202).

7. The production device for preparing hydroxypivalaldehyde as an intermediate of neopentyl glycol according to claim 1, characterized in that: A material pump 1 (19) is provided on the pipeline connected to the bottom outlet of the condensation reactor 1 (8), and a material pump 2 (18) is provided on the pipeline connected to the bottom outlet of the condensation reactor 2 (11).

8. The production device for preparing hydroxypivalaldehyde as an intermediate of neopentyl glycol according to claim 1, characterized in that: The bottom outlet of the condensation reactor 1 (8) is connected to the inlet of the heat exchanger 1 (9), and the outlet of the heat exchanger 1 (9) is connected to the bottom inlet of the condensation reactor 1 (8); the bottom outlet of the condensation reactor 2 (11) is connected to the inlet of the heat exchanger 2 (10), and the outlet of the heat exchanger 2 (10) is connected to the bottom inlet of the condensation reactor 2 (11).

9. The production device for preparing hydroxypivalaldehyde as an intermediate of neopentyl glycol according to claim 1, characterized in that: The bottom of the distillation tower (12) is connected to the reboiling heat exchanger (13) and the third heat exchanger (14) respectively through a bottom pipeline (1301), and a material pump (17) is arranged on the bottom pipeline (1301); the bottom outlet of the distillation tower (12) is connected to the inlet of the reboiling heat exchanger (13), and the outlet of the reboiling heat exchanger (13) is connected to the lower inlet of the distillation tower (12).

10. The production device for preparing hydroxypivalaldehyde as an intermediate of neopentyl glycol according to claim 1, characterized in that: The outlet of the tower top heat exchanger (15) is connected to the condensation reactor one (8) through a circulation pipeline (1501), and a material pump four (20) is arranged on the circulation pipeline (1501); the top outlet of the distillation tower (12) is connected to the inlet of the tower top heat exchanger (15), and the outlet of the tower top heat exchanger (15) is connected to the upper inlet of the distillation tower (12).

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