Disposal method and system of by-product tail gas for production of tetrachloroethylene

Abstract

The invention provides a disposal method and system of by-product tail gas for production of tetrachloroethylene. The disposal method comprises the following steps of compressing and condensing the by-product tail gas for the production of tetrachloroethylene to obtain liquid carbon tetrachloride and mixed gas, wherein obtained carbon tetrachloride can continue to participate in preparation of tetrachloroethylene; using the obtained mixed gas as a raw material to carry out thermal chlorination reaction with methane chloride and meanwhile using obtained by-product hydrogen chloride as a raw material to be sent to a hydrochlorination reaction system. The method has the advantages that the procedures are short, ultra-low condensation temperature is not required, and the cost is low. By recycling the by-products, the consumption of the raw materials is reduced, and the production cost is decreased. The problem about how to dispose a large amount of hydrogen chloride generated in the production process of tetrachloroethylene is solved, the discharge of three kinds of waste is reduced, the tail gas is fully utilized, and the the economic value and the environmental benefits are increasedat the same time.

Description

technical field

[0001] The invention relates to a treatment method and a treatment system for by-product tail gas produced from tetrachlorethylene, belonging to the field of process tail gas treatment. Background technique

[0002] Methane chlorides (including monochloromethane, dichloromethane, chloroform and carbon tetrachloride) and tetrachloroethylene are important chemical raw materials. The existing domestic production of perchlorethylene mainly adopts C1-C3 hydrocarbon thermal chlorination process, which will produce a large amount of tail gas, which contains a large amount of hydrogen chloride gas, a small amount of chlorine gas and carbon tetrachloride. These tail gases are usually used to prepare low-value dilute hydrochloric acid, and the demand for hydrochloric acid is limited in the market, which often affects the operating load of the device due to slow sales of hydrochloric acid.

[0003] Therefore, the reasonable treatment and application of the above-mentio...

Examples

Embodiment 1

[0028] A treatment system for producing tetrachlorethylene by-product tail gas, such as figure 1 Shown, comprise: compression system 1, condensation system 2, carbon tetrachloride storage tank 3 and thermal chlorination reaction system (comprising preheater 5 and thermal chlorination reactor 6, preheater 5 and thermal chlorination reactor 6 are connected in sequence); the compression system 1, the condensation system 2, the carbon tetrachloride storage tank 3 are connected in sequence by pipelines, the carbon tetrachloride storage tank 3 is connected with the tetrachlorethylene production system 4 by the circulation device, and the tetrachloride The ethylene production system 4 is connected to the compression system 1 through pipelines; the condensing system 2 is also connected to the preheater 5 through pipelines; the thermal chlorination reactor 6 is connected to the hydrochlorination reaction system 7 through a condensing device.

[0029] The compression system 1, condensat...

Embodiment 2

[0031] Utilize the processing system described in embodiment 1 to process the method for producing tetrachlorethylene by-product tail gas, comprise main components in the production tetrachlorethylene by-product tail gas that comes out from tetrachlorethylene production system 4: hydrogen chloride 80.3%wt, chlorine and tetrachloride Carbon 10.2%wt.

[0032] The by-product tail gas W1 from the production of tetrachlorethylene enters the compression system 1, is compressed to 1.0MPa, and then enters the condensation system 2, and the condensation temperature is -10°C; after condensation, liquid carbon tetrachloride and mixed gas (carbon tetrachloride in the mixed gas content is 1wt%); liquid carbon tetrachloride enters carbon tetrachloride storage tank 3, returns to tetrachlorethylene production system 4 through circulation device and continues to participate in the preparation of tetrachlorethylene; gained mixed gas main component after condensation is: 85.3%wt Hydrogen chlorid...

Embodiment 3

[0034] Utilize the processing system described in embodiment 1 to process the method for producing tetrachlorethylene by-product tail gas, comprise main components in the production tetrachlorethylene by-product tail gas that comes out from tetrachlorethylene production system 4: hydrogen chloride 80.3%wt, chlorine and tetrachloride Carbon 10.2%wt.

[0035]The by-product tail gas W1 from the production of tetrachlorethylene enters the compression system 1, is compressed to 1.2MPa, and then enters the condensation system 2, and the condensation temperature is -5°C; after condensation, liquid carbon tetrachloride and mixed gas (carbon tetrachloride in the mixed gas content is 1.6wt%); liquid carbon tetrachloride enters the carbon tetrachloride storage tank 3, returns to the tetrachlorethylene production system 4 and continues to participate in the preparation of tetrachlorethylene through the circulation device; the main component of the mixed gas obtained after condensation is: ...

technical field

[0001] The invention relates to a treatment method and a treatment system for by-product tail gas produced from tetrachlorethylene, belonging to the field of process tail gas treatment. Background technique

[0002] Methane chlorides (including monochloromethane, dichloromethane, chloroform and carbon tetrachloride) and tetrachloroethylene are important chemical raw materials. The existing domestic production of perchlorethylene mainly adopts C1-C3 hydrocarbon thermal chlorination process, which will produce a large amount of tail gas, which contains a large amount of hydrogen chloride gas, a small amount of chlorine gas and carbon tetrachloride. These tail gases are usually used to prepare low-value dilute hydrochloric acid, and the demand for hydrochloric acid is limited in the market, which often affects the operating load of the device due to slow sales of hydrochloric acid.

[0003] Therefore, the reasonable treatment and application of the above-mentio...

Examples

Embodiment 1

[0028] A treatment system for producing tetrachlorethylene by-product tail gas, such as figure 1 Shown, comprise: compression system 1, condensation system 2, carbon tetrachloride storage tank 3 and thermal chlorination reaction system (comprising preheater 5 and thermal chlorination reactor 6, preheater 5 and thermal chlorination reactor 6 are connected in sequence); the compression system 1, the condensation system 2, the carbon tetrachloride storage tank 3 are connected in sequence by pipelines, the carbon tetrachloride storage tank 3 is connected with the tetrachlorethylene production system 4 by the circulation device, and the tetrachloride The ethylene production system 4 is connected to the compression system 1 through pipelines; the condensing system 2 is also connected to the preheater 5 through pipelines; the thermal chlorination reactor 6 is connected to the hydrochlorination reaction system 7 through a condensing device.

[0029] The compression system 1, condensat...

Embodiment 2

[0031] Utilize the processing system described in embodiment 1 to process the method for producing tetrachlorethylene by-product tail gas, comprise main components in the production tetrachlorethylene by-product tail gas that comes out from tetrachlorethylene production system 4: hydrogen chloride 80.3%wt, chlorine and tetrachloride Carbon 10.2%wt.

[0032] The by-product tail gas W1 from the production of tetrachlorethylene enters the compression system 1, is compressed to 1.0MPa, and then enters the condensation system 2, and the condensation temperature is -10°C; after condensation, liquid carbon tetrachloride and mixed gas (carbon tetrachloride in the mixed gas content is 1wt%); liquid carbon tetrachloride enters carbon tetrachloride storage tank 3, returns to tetrachlorethylene production system 4 through circulation device and continues to participate in the preparation of tetrachlorethylene; gained mixed gas main component after condensation is: 85.3%wt Hydrogen chlorid...

Embodiment 3

[0034] Utilize the processing system described in embodiment 1 to process the method for producing tetrachlorethylene by-product tail gas, comprise main components in the production tetrachlorethylene by-product tail gas that comes out from tetrachlorethylene production system 4: hydrogen chloride 80.3%wt, chlorine and tetrachloride Carbon 10.2%wt.

[0035]The by-product tail gas W1 from the production of tetrachlorethylene enters the compression system 1, is compressed to 1.2MPa, and then enters the condensation system 2, and the condensation temperature is -5°C; after condensation, liquid carbon tetrachloride and mixed gas (carbon tetrachloride in the mixed gas content is 1.6wt%); liquid carbon tetrachloride enters the carbon tetrachloride storage tank 3, returns to the tetrachlorethylene production system 4 and continues to participate in the preparation of tetrachlorethylene through the circulation device; the main component of the mixed gas obtained after condensation is: ...

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