Tail gas treatment device for methylisothiazolinone production

Abstract

The utility model belongs to the technical field of chemical production, and discloses a tail gas treatment device for methylisothiazolinone production, which comprises a spray tower, an acid absorption tower, an incinerator, a heat exchanger, an activated carbon adsorption tower, an induced draft fan and a chimney which are sequentially communicated through pipelines and valves, a gas outlet of the spray tower is communicated with a gas inlet of the acid absorption tower, a gas outlet of the acid absorption tower is communicated with a gas inlet of the incinerator, a gas outlet of the incinerator is communicated with a gas inlet of the heat exchanger, a gas outlet of the heat exchanger is communicated with a gas inlet of the activated carbon adsorption tower, and a gas outlet of the activated carbon adsorption tower is communicated with a gas inlet of the induced draft fan. An air outlet of the induced draft fan is communicated with an air inlet of the chimney; the acid absorption tower is provided with a circulating pump and a liquid storage tank, and a liquid outlet of the liquid storage tank is communicated to the methylamine recycling device through a pipeline and a valve. The device is reasonable in treatment process design, simple in structure and good in treatment effect.

Description

Technical Field

[0001] This utility model belongs to the field of chemical production technology, specifically relating to a tail gas treatment device for the production of methylisothiazolinone. Background Technology

[0002] Methylisothiazolinone is a type of isothiazolinone compound, mainly used in industrial bactericides and fungicides, crop disease control, and marine antifouling agents. Currently, methylisothiazolinones (5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one) are produced by reacting methyl acrylate with sulfides. The production process generates tail gas containing methylamine. Improper treatment or direct emission of this tail gas without treatment can seriously pollute the environment and endanger human safety. Therefore, appropriate treatment of this tail gas is necessary, but no relevant publicly available information has been found. Summary of the Invention

[0003] The technical problem to be solved by this utility model is to provide a tail gas treatment device for the production of methylisothiazolinone, which overcomes the defects in the prior art, can properly treat the tail gas generated during the production of methylisothiazolinone, and has a reasonable design, simple structure, and good treatment effect.

[0004] To solve the above-mentioned technical problems, the technical solution of this utility model is as follows:

[0005] A tail gas treatment device for the production of methylisothiazolinone includes a spray tower, an acid absorption tower, an incinerator, a heat exchanger, an activated carbon adsorption tower, an induced draft fan, and a chimney, which are connected in sequence by pipes and valves. The outlet of the spray tower is connected to the inlet of the acid absorption tower, the outlet of the acid absorption tower is connected to the inlet of the incinerator, the outlet of the incinerator is connected to the inlet of the heat exchanger, the outlet of the heat exchanger is connected to the inlet of the activated carbon adsorption tower, the outlet of the activated carbon adsorption tower is connected to the inlet of the induced draft fan, and the outlet of the induced draft fan is connected to the inlet of the chimney. The acid absorption tower is equipped with a circulating pump and a storage tank, and the outlet of the storage tank is connected to a methylamine recovery and utilization device by pipes and valves.

[0006] Preferably, the air inlet of the spray tower is equipped with an LEL detector. The alarm value of the LEL detector is ≤25% LEL. This prevents the risk of explosion caused by high methylamine concentration.

[0007] Preferably, the spray tower is equipped with a water inlet, which is connected to a spray water storage tank externally via a pipe and a spraying device internally. The spraying is used to remove particulate matter from the exhaust gas and reduce its temperature.

[0008] Preferably, the acid absorption tower is a sulfuric acid absorption tower or a hydrochloric acid absorption tower, connected to an external sulfuric acid storage tank or a hydrochloric acid storage tank; the methylamine recovery and utilization device is a methylamine sulfate recovery and utilization device or a methylamine hydrochloride recovery and utilization device.

[0009] Preferably, the acid absorption tower is equipped with an online pH monitor. This monitor is used to detect the acidity or alkalinity of the absorption solution and adjust the acidity or alkalinity of the absorption solution using appropriate devices.

[0010] Preferably, the incinerator is an RTO (Regenerative Thermal Oxidizer).

[0011] Preferably, the activated carbon adsorption tower is provided with several activated carbon adsorption layers. The activated carbon adsorption layers are filled with acid-modified activated carbon (to enhance the adsorption capacity for methylamine).

[0012] Due to the adoption of the above technical solution, the beneficial effects of this utility model are:

[0013] This invention first removes particulate matter from the exhaust gas through spraying, then removes most of the methylamine and alkaline substances from the exhaust gas through acid absorption, and then removes combustibles from the exhaust gas through oxidation combustion. After cooling, the gas is further treated by activated carbon adsorption, and the resulting gas meets emission standards and can be emitted. At the same time, the saturated methylamine sulfate solution or methylamine hydrochloride solution obtained during the acid absorption process is recycled to obtain methylamine sulfate or methylamine hydrochloride products, turning waste into treasure.

[0014] In summary, the processing method of this utility model is reasonably designed, has a simple structure, achieves good processing results, and can also increase enterprise benefits. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of this utility model;

[0016] In the diagram, 1 is a spray tower; 2 is an acid absorption tower; 3 is an incinerator; 4 is a heat exchanger; 5 is an activated carbon adsorption tower; 6 is an induced draft fan; 7 is a chimney; 8 is a storage tank; 9 is a methylamine recovery and utilization device; 10 is an LEL detector; 11 is a spray water storage tank; and 12 is a sulfuric acid storage tank. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] Example 1:

[0019] like Figure 1As shown, a tail gas treatment device for the production of methylisothiazolinone includes a spray tower 1, an acid absorption tower 2, an incinerator 3, a heat exchanger 4, an activated carbon adsorption tower 5, an induced draft fan 6, and a chimney 7, which are connected in sequence through pipes (not shown) and valves (not shown). The outlet of the spray tower 1 is connected to the inlet of the acid absorption tower 2, the outlet of the acid absorption tower 2 is connected to the inlet of the incinerator 3, the outlet of the incinerator 3 is connected to the inlet of the heat exchanger 4, the outlet of the heat exchanger 4 is connected to the inlet of the activated carbon adsorption tower 5, the outlet of the activated carbon adsorption tower 5 is connected to the inlet of the induced draft fan 6, and the outlet of the induced draft fan 6 is connected to the inlet of the chimney 7. The acid absorption tower 2 is equipped with a circulating pump (not shown) and a storage tank 8. The outlet of the storage tank 8 is connected to a methylamine recovery and utilization device 9 through pipes and valves.

[0020] The air inlet of spray tower 1 is equipped with an LEL detector 10; the water inlet of the spray tower is connected to the spray water storage tank 11 through a pipeline; the acid absorption tower 2 is connected to the sulfuric acid storage tank 12.

[0021] In actual production, the tail gas generated during the production of methylisothiazolinone is first transported to spray tower 1 through a collection device. Before entering spray tower 1, the inlet gas temperature is controlled to be less than 50°C, and the concentration of methylamine is detected by LEL detector 10. The pH value of the spray water is maintained at neutral (6-8). After the particles in the tail gas are removed by spraying, it enters acid absorption tower 2, where 5-10% dilute sulfuric acid is introduced to absorb the methylamine in the tail gas, forming methylamine sulfate. The sulfate is collected in storage tank 8, and the liquid in storage tank 8 can be circulated by a circulation pump until a saturated methylamine sulfate solution is formed. The liquid is discharged into the methylamine recovery and utilization device 9 to recover and utilize the methylamine sulfate, and then dilute sulfuric acid is reintroduced for acid absorption; after acid absorption, the methylamine removal rate can reach more than 90%; the treated tail gas enters the incinerator 3 for oxidation and combustion at 800-950℃ to further remove combustible substances in the tail gas; the gas after combustion is cooled by the heat exchanger 4 and then enters the activated carbon adsorption tower 5 to further adsorb the remaining methylamine and other impurities; the gas discharged from the activated carbon adsorption tower 5 is tested and fully meets the emission standards, and is introduced into the chimney 7 by the induced draft fan 6 (which simultaneously generates negative pressure for the equipment in the previous process) for emission.

[0022] It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

Claims

1. A tail gas treatment device for methylisothiazolinone production, characterized by: The system includes a spray tower, an acid absorption tower, an incinerator, a heat exchanger, an activated carbon adsorption tower, an induced draft fan, and a chimney, all connected sequentially via pipes and valves. The outlet of the spray tower is connected to the inlet of the acid absorption tower, the outlet of the acid absorption tower is connected to the inlet of the incinerator, the outlet of the incinerator is connected to the inlet of the heat exchanger, the outlet of the heat exchanger is connected to the inlet of the activated carbon adsorption tower, the outlet of the activated carbon adsorption tower is connected to the inlet of the induced draft fan, and the outlet of the induced draft fan is connected to the inlet of the chimney. The acid absorption tower is equipped with a circulating pump and a storage tank, and the outlet of the storage tank is connected to a methylamine recovery and utilization device via pipes and valves.

2. The exhaust gas treatment device for methylisothiazolinone production according to claim 1, characterized by: The air inlet of the spray tower is equipped with an LEL detector.

3. The tail gas treatment device for the production of methylisothiazolinone as described in claim 1, characterized in that: The spray tower is equipped with a water inlet, which is connected to a spray water storage tank via a pipe and a spray device inside.

4. The exhaust gas treatment device for methylisothiazolinone production according to claim 1, characterized by: The acid absorption tower is a sulfuric acid absorption tower or a hydrochloric acid absorption tower, and is connected to an external sulfuric acid storage tank or hydrochloric acid storage tank.

5. The exhaust gas treatment device for methylisothiazolinone production according to claim 1, characterized by: The acid absorption tower is equipped with an online pH monitor.

6. The exhaust gas treatment device for methylisothiazolinone production according to claim 1, characterized by: The incinerator is an RTO (Regenerative Thermal Oxidizer).

7. The exhaust gas treatment device for methylisothiazolinone production according to claim 1, characterized by: The activated carbon adsorption tower is equipped with several activated carbon adsorption layers.

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