阅读说明：本技术 一种氯乙烯生产工段乙炔气干燥脱水方法 (Acetylene gas drying and dehydrating method for vinyl chloride production section ) 是由 李国华 周翔 方文韬 于 2020-11-20 设计创作，主要内容包括：本发明公开了一种氯乙烯生产工段乙炔气干燥脱水方法,其包括：将湿乙炔气从干燥塔底部连续进入塔内,同时亲水性离子液体作为吸湿剂从干燥塔顶部连续喷淋进入塔内,控制塔内温度在-10℃～30℃之间进行气液接触,脱水后的乙炔气从塔顶连续排出,干燥塔塔底得到富水的亲水性离子液体；富水的亲水性离子液体进入闪蒸罐进行再生,再生后的亲水性离子液体回用至干燥塔塔顶继续作为吸湿剂使用。本发明工艺流程简单,易于操作,以亲水性离子液体作为吸湿剂,吸湿效果好,可以将乙炔气中的水分控制在100ppm以下。亲水性离子液体作为吸湿剂,绿色环保,具有良好的热稳定性和化学稳定性,易与其它物质分离,可以循环利用。(The invention discloses a method for drying and dehydrating acetylene gas in a chloroethylene production section, which comprises the following steps: continuously feeding wet acetylene gas into the tower from the bottom of the drying tower, continuously spraying hydrophilic ionic liquid serving as a moisture absorbent from the top of the drying tower into the tower, controlling the temperature in the tower to be between-10 and 30 ℃ for gas-liquid contact, continuously discharging the dehydrated acetylene gas from the top of the tower, and obtaining water-rich hydrophilic ionic liquid at the bottom of the drying tower; and (3) the water-rich hydrophilic ionic liquid enters a flash tank for regeneration, and the regenerated hydrophilic ionic liquid is recycled to the top of the drying tower to be continuously used as a moisture absorbent. The method has simple process flow and easy operation, takes the hydrophilic ionic liquid as the moisture absorbent, has good moisture absorption effect, and can control the moisture in the acetylene gas to be below 100 ppm. The hydrophilic ionic liquid is used as a moisture absorbent, is green and environment-friendly, has good thermal stability and chemical stability, is easy to separate from other substances, and can be recycled.)

1. A method for drying and dehydrating acetylene gas in a vinyl chloride production section comprises the following steps:

continuously feeding wet acetylene gas into the tower from the bottom of the drying tower, continuously spraying hydrophilic ionic liquid serving as a moisture absorbent from the top of the drying tower into the tower, controlling the temperature in the tower to be between-10 and 30 ℃ for gas-liquid contact, continuously discharging the dehydrated acetylene gas from the top of the tower, and obtaining water-rich hydrophilic ionic liquid at the bottom of the drying tower; and (3) the water-rich hydrophilic ionic liquid enters a flash tank for regeneration, and the regenerated hydrophilic ionic liquid is recycled to the top of the drying tower to be continuously used as a moisture absorbent.

2. The method for drying and dehydrating acetylene gas at a vinyl chloride production section according to claim 1, characterized in that: the gas-liquid contact temperature is controlled between-10 ℃ and 10 ℃.

3. The method for drying and dehydrating acetylene gas at a vinyl chloride production section according to claim 1, characterized in that: the temperature of the wet acetylene gas and the hydrophilic ionic liquid before entering the drying tower is controlled between-10 ℃ and 30 ℃.

4. The method for drying and dehydrating acetylene gas at a vinyl chloride production section according to claim 3, characterized in that: the temperature of the wet acetylene gas and the hydrophilic ionic liquid before entering the drying tower is controlled between-10 ℃ and 10 ℃.

5. The method for drying and dehydrating acetylene gas in a vinyl chloride production section according to any one of claims 1 to 4, wherein: the moisture content of the wet acetylene gas was 15000-20000 ppm.

6. The method for drying and dehydrating acetylene gas in a vinyl chloride production section according to any one of claims 1 to 4, wherein: the hydrophilic ionic liquid is at least one of 1-ethyl-3-methylimidazole acetate, 1-butyl-3-methylimidazole diethyl phosphate, 1-ethyl-3-methylimidazole dimethyl phosphate, 1-butyl-3-methylimidazole dimethyl phosphate, 1-ethyl-3-methylimidazole tetrafluoroborate and 1-ethyl-3-methylimidazole ethyl sulfate.

7. The method for drying and dehydrating acetylene gas in a vinyl chloride production section according to any one of claims 1 to 4, wherein: the gas-liquid ratio of the wet acetylene gas to the moisture absorbent is 0.2-30: 1.

8. the method for drying and dehydrating acetylene gas in a vinyl chloride production section according to any one of claims 1 to 4, wherein: the flow rate of the wet acetylene gas entering the drying tower is 30-500 ml/min.

9. The method for drying and dehydrating acetylene gas in a vinyl chloride production section according to any one of claims 1 to 4, wherein: the drying towers are more than 2 drying towers connected in series, so that acetylene gas discharged from the top of the former drying tower continuously enters from the bottom of the latter drying tower, and water-rich hydrophilic ionic liquid obtained from the bottom of each drying tower enters a flash tank for regeneration.

10. The method for drying and dehydrating acetylene gas at a vinyl chloride production section according to claim 9, characterized in that: the residence time of the wet acetylene gas in each drying tower is 30-100 s.

The technical field is as follows:

the invention is suitable for the field of acetylene gas post-treatment, and particularly relates to a method for drying and dehydrating acetylene gas in a vinyl chloride production section.

Background art:

at present, the production process of Vinyl Chloride (VCM) is quite mature, and generally comprises a calcium carbide method (natural gas acetylene method), a combination method, an oxychlorination method and a balanced oxychlorination method, wherein the production process of the calcium carbide method accounts for a quite large proportion. These methods all have high requirements for the gas-water content of the raw material. The common methods for drying acetylene gas at present are as follows: (1) acetylene gas is mixed with HCl produced by a synthesis furnace in a synthesis section, and a method of freeze drying brine at the temperature of-35 ℃ is adopted, which has the defects of poor water removal effect, graphite cooler leakage, catalyst caking, low utilization rate of a converter, corrosion of the converter and the like, and (2) a method of drying and dehydrating concentrated sulfuric acid has the defects of large occupied area, large investment, large difficulty in cleaning and overhauling during overhaul, more generated waste acid and great harm to environmental protection.

The invention content is as follows:

the technical problem to be solved by the invention is to provide the acetylene gas drying and dehydrating method for the vinyl chloride production section, which has the advantages of good water removal effect, simple process, simple operation and environmental protection, and aims at overcoming the defects of the prior art.

In order to realize the purpose, the invention adopts the following specific technical scheme:

a method for drying and dehydrating acetylene gas in a vinyl chloride production section comprises the following steps:

continuously feeding wet acetylene gas into the tower from the bottom of the drying tower, continuously spraying hydrophilic ionic liquid serving as a moisture absorbent from the top of the drying tower into the tower, controlling the temperature in the tower to be between-10 and 30 ℃ for gas-liquid contact, continuously discharging the dehydrated acetylene gas from the top of the tower, and obtaining water-rich hydrophilic ionic liquid at the bottom of the drying tower; and (3) the water-rich hydrophilic ionic liquid enters a flash tank for regeneration, and the regenerated hydrophilic ionic liquid is recycled to the top of the drying tower to be continuously used as a moisture absorbent.

In the present invention, in order to improve the water absorption effect of the ionic liquid, the gas-liquid contact temperature needs to be controlled to be between-10 ℃ and 30 ℃, preferably between-10 ℃ and 10 ℃. In order to conveniently control the temperature in the drying tower, the temperature of the wet acetylene gas and the hydrophilic ionic liquid before entering the drying tower is preferably controlled to be-10-30 ℃, for example, the wet acetylene gas can be cooled by a cooler before entering the drying tower, so that the temperature of the acetylene gas after being cooled by the cooler is-10-30 ℃ (preferably-10 ℃); for example, the hydrophilic ionic liquid after the flash tank regeneration treatment needs to be cooled to-10 ℃ to 30 ℃ (preferably-10 ℃ to 10 ℃) before entering the drying tower.

Preferably, the moisture content of the wet acetylene gas is 15000-20000 ppm.

Preferably, the hydrophilic ionic liquid is 1-ethyl-3-methylimidazole acetate (EMIMAC), 1-butyl-3-methylimidazole acetate (BMIMAC), 1-butyl-3-methylimidazole phosphate diethyl ester salt (BMIMDEP), 1-ethyl-3-methylimidazole phosphate diethyl ester salt (EMIMDEP), 1-ethyl-3-methylimidazole phosphate dimethyl ester salt (EMIMDMP), 1-butyl-3-methylimidazole phosphate dimethyl ester salt (BMIMDMP), EMBF IMDMP₄(1-Ethyl-3-methylimidazolium tetrafluoroborate), EMIMETSO₄At least one of (1-ethyl-3-methylimidazolium ethyl sulfate).

Preferably, the gas-liquid ratio of the wet acetylene gas to the moisture absorbent is 0.2-30: 1.

preferably, the flow rate of the wet acetylene gas entering the drying tower is 30-500 ml/min.

Preferably, the drying towers are more than 2 drying towers connected in series, acetylene gas discharged from the top of the former drying tower continuously enters from the bottom of the latter drying tower, and the water-rich hydrophilic ionic liquid obtained from the bottom of each drying tower enters a flash tank for regeneration.

Preferably, the residence time of the wet acetylene gas in each drying tower is 30-100 s.

Compared with the prior art, the invention has the following specific advantages:

(1) the invention takes the hydrophilic ionic liquid as the moisture absorbent, has good moisture absorption effect and can control the moisture in the acetylene gas to be less than 100 ppm.

(2) The hydrophilic ionic liquid is used as a moisture absorbent, is green and environment-friendly, has good thermal stability and chemical stability, is easy to separate from other substances, and can be recycled.

(3) The process flow is simple and easy to operate.

Description of the drawings:

fig. 1 is a schematic structural diagram of an acetylene gas drying and dehydrating device in an embodiment of the present application. Wherein: 1-freezing tower, 2-drying tower I, 3-cooler, 4-drying tower II, 5-cooler, 6-constant flow pump, 7-constant flow pump, 8-flash evaporation tank.

The specific implementation mode is as follows:

the technical solution of the present invention is further illustrated by the following specific examples, but the scope of the present invention is not limited thereto:

example 1

As shown in fig. 1, after the wet acetylene gas produced in the section of producing vinyl chloride acetylene by a calcium carbide method is cooled by a freezing tower, the wet acetylene gas with the temperature of 10 ℃ and the moisture content of 20000ppm continuously enters 2 drying towers connected in series from the bottom through a flow meter at the flow rate of 100ml/min, the retention time of the wet acetylene gas in each drying tower is 50s, meanwhile, an EMIMDEP hydrophilic ionic liquid solution with the temperature of 0 ℃ is continuously sent into the towers for spraying through a constant flow pump according to the gas-liquid ratio of 15: 1, and finally, the moisture content of the acetylene gas at the top outlets of the drying towers is reduced to 100 ppm. And (3) enabling EMIMDEP ionic liquid rich in water at the bottom of the flash tank to enter a flash tank for regeneration, cooling hydrophilic ionic liquid at the bottom of the flash tank to 0 ℃ through a cooler, and sending the hydrophilic ionic liquid to the top of the drying tower to be continuously used as a moisture absorbent.

Example 2

As shown in fig. 1, after the wet acetylene gas produced in the section of producing vinyl chloride acetylene by a calcium carbide method is cooled by a freezing tower, the temperature is 10 ℃, the wet acetylene gas with the moisture content of 20000ppm continuously enters 2 drying towers connected in series from the bottom through a flow meter at the flow rate of 100ml/min, the retention time of the wet acetylene gas in each drying tower is 90s, meanwhile, an EMIMDEP hydrophilic ionic liquid solution with the temperature of-5 ℃ is continuously sent into the towers for spraying through a constant flow pump according to the gas-liquid ratio of 15: 1, and finally, the water content of the acetylene gas at the top outlets of the drying towers is reduced to 87 ppm. And (3) enabling EMIMDEP ionic liquid rich in water at the bottom of the flash tank to enter a flash tank for regeneration, cooling the hydrophilic ionic liquid at the bottom of the flash tank to-5 ℃ through a cooler, and conveying the hydrophilic ionic liquid to the top of the drying tower to be continuously used as a moisture absorbent.

Example 3

As shown in fig. 1, after the wet acetylene gas produced in the section of producing vinyl chloride acetylene by a calcium carbide method is cooled by a freezing tower, the temperature is 10 ℃, the wet acetylene gas with the moisture content of 20000ppm continuously enters 2 drying towers connected in series from the bottom through a flow meter at the flow rate of 200ml/min, the retention time of the wet acetylene gas in each drying tower is 90s, meanwhile, an EMIMDMP hydrophilic ionic liquid solution with the temperature of 0 ℃ is continuously sent into the towers for spraying through a constant flow pump according to the gas-liquid ratio of 20 to 1, and finally, the moisture content of the acetylene gas at the top outlets of the drying towers is reduced to 76 ppm. And (3) enabling EMIMDMP ionic liquid rich in water at the bottom of the flash tank to enter a flash tank for regeneration, cooling hydrophilic ionic liquid at the bottom of the flash tank to 0 ℃ through a cooler, and sending the hydrophilic ionic liquid to the top of the drying tower to be continuously used as a moisture absorbent.

Example 4

As shown in fig. 1, after the wet acetylene gas produced in the section of producing vinyl chloride acetylene by a calcium carbide method is cooled by a freezing tower, the temperature is 10 ℃, the wet acetylene gas with the moisture content of 20000ppm continuously enters 2 drying towers connected in series from the bottom through a flow meter at the flow rate of 200ml/min, the retention time of the wet acetylene gas in each drying tower is 100s, meanwhile, an EMIMDMP hydrophilic ionic liquid solution with the temperature of-5 ℃ is continuously sent into the towers for spraying through a constant flow pump according to the gas-liquid ratio of 20: 1, and finally, the moisture content of the acetylene gas at the top outlets of the drying towers is reduced to 65 ppm. And (3) enabling EMIMDMP ionic liquid rich in water at the bottom of the flash tank to enter a flash tank for regeneration, cooling hydrophilic ionic liquid at the bottom of the flash tank to-5 ℃ through a cooler, and conveying the hydrophilic ionic liquid to the top of the drying tower to be continuously used as a moisture absorbent.

Example 5

As shown in fig. 1, after the wet acetylene gas produced in the section of producing vinyl chloride acetylene by a calcium carbide method is cooled by a freezing tower, the temperature is 10 ℃, the wet acetylene gas with the moisture content of 20000ppm continuously enters 2 drying towers connected in series from the bottom through a flow meter at the flow rate of 200ml/min, the retention time of the wet acetylene gas in each drying tower is 100s, meanwhile, an EMIMAC hydrophilic ionic liquid solution with the temperature of 0 ℃ is continuously sent into the towers for spraying through a constant flow pump according to the gas-liquid ratio of 20 to 1, and finally, the moisture content of the acetylene gas at the top outlets of the drying towers is reduced to 50 ppm. And (3) enabling EMIMAC ionic liquid rich in water at the bottom of the flash tank to enter a flash tank for regeneration, cooling hydrophilic ionic liquid at the bottom of the flash tank to 0 ℃ through a cooler, and conveying the hydrophilic ionic liquid to the top of the drying tower to be continuously used as a moisture absorbent.

Example 6

As shown in fig. 1, after the wet acetylene gas produced in the section of producing vinyl chloride acetylene by a calcium carbide method is cooled by a freezing tower, the temperature is 10 ℃, the wet acetylene gas with the moisture content of 20000ppm continuously enters 2 drying towers connected in series from the bottom through a flow meter at the flow rate of 200ml/min, the retention time of the wet acetylene gas in each drying tower is 100s, meanwhile, an EMIMAC hydrophilic ionic liquid solution with the temperature of-10 ℃ is continuously sent into the towers for spraying through a constant flow pump according to the gas-liquid ratio of 20: 1, and finally, the moisture content of the acetylene gas at the top outlets of the drying towers is reduced to 30 ppm. And (3) enabling EMIMAC ionic liquid rich in water at the bottom of the flash tank to enter a flash tank for regeneration, cooling hydrophilic ionic liquid at the bottom of the flash tank to-10 ℃ through a cooler, and conveying the hydrophilic ionic liquid to the top of the drying tower to be continuously used as a moisture absorbent.

Example 7

As shown in figure 1, after the wet acetylene gas produced in a section for producing vinyl chloride acetylene by a calcium carbide method is cooled by a freezing tower, the temperature is 10 ℃, the wet acetylene gas with the moisture content of 20000ppm continuously enters 2 drying towers connected in series from the bottom at the flow rate of 200ml/min through a flowmeter, the retention time of the wet acetylene gas in each drying tower is 100s, meanwhile, a 0 ℃ mixed hydrophilic ionic liquid (EMIMAC and EMIMDEP mass ratio is 1: 1) solution is continuously sent into the towers for spraying through a constant flow pump according to the gas-liquid ratio of 20: 1, and finally, the moisture content of the acetylene gas at the top outlet of the drying towers is reduced to 20 ppm. And the mixed ionic liquid rich in water at the bottom of the flash tank enters a flash tank for regeneration, and the hydrophilic ionic liquid at the bottom of the flash tank is cooled to-10 ℃ by a cooler and is sent to the top of the drying tower to be continuously used as a moisture absorbent.

Example 8

As shown in figure 1, after the wet acetylene gas produced in a section for producing vinyl chloride acetylene by a calcium carbide method is cooled by a freezing tower, the temperature is 10 ℃, the wet acetylene gas with the moisture content of 20000ppm continuously enters 2 drying towers which are connected in series from the bottom at the flow rate of 200ml/min through a flowmeter, the retention time of the wet acetylene gas in each drying tower is 100s, meanwhile, a mixed hydrophilic ionic liquid (EMIMAC and EMIMDEP mass ratio is 1: 1) solution at the temperature of-10 ℃ is 20: 1 according to the gas-liquid ratio, the mixed hydrophilic ionic liquid is continuously sent to the towers for spraying through a constant flow pump, and finally, the moisture content of the acetylene gas at the top outlet of the drying towers is reduced to 15 ppm. And the mixed ionic liquid rich in water at the bottom of the flash tank enters a flash tank for regeneration, and the hydrophilic ionic liquid at the bottom of the flash tank is cooled to-10 ℃ by a cooler and is sent to the top of the drying tower to be continuously used as a moisture absorbent.