阅读说明：本技术 无汞触媒催化生产氯乙烯的工艺 (process for producing vinyl chloride by catalysis of mercury-free catalyst ) 是由 张国杰 马永利 鲁丽敏 吕峰 杨振东 乔丽霞 杨峰 何秀梅 王艳辉 苏砚平 卢建 于 2019-07-22 设计创作，主要内容包括：本发明公开了一种无汞触媒催化生产氯乙烯的工艺,包括：S1.触媒装填；S2.触媒活化；S3.合成氯乙烯。本发明公开的无汞触媒环境友好,避免了传统氯化汞类催化剂生产氯乙烯时,汞对环境的污染；而且,无汞触媒相对传统的氯化汞类催化剂,其价格较低,成本低廉,更适于可持续发展。本发明工艺简单,操作方便,针对性强,本发明公开的无汞触媒利用本工艺生产氯乙烯时,催化活性高,生产的氯乙烯产率高,纯度好,产率可达95％以上,纯度可达98％以上,完全可替代传统的氯化汞类催化剂,适于大规模工业生产。(The invention discloses a process for producing chloroethylene by using mercury-free catalyst catalysis, which comprises the following steps: s1, filling a catalyst; s2, activating a catalyst; and S3, synthesizing chloroethylene. The mercury-free catalyst disclosed by the invention is environment-friendly, and avoids the pollution of mercury to the environment when the traditional mercury chloride catalyst is used for producing vinyl chloride; in addition, compared with the traditional mercury chloride catalyst, the mercury-free catalyst has lower price and low cost and is more suitable for sustainable development. The mercury-free catalyst disclosed by the invention is simple in process, convenient to operate and strong in pertinence, and when the mercury-free catalyst is used for producing vinyl chloride, the catalytic activity is high, the yield of the produced vinyl chloride is high, the purity is good, the yield can reach more than 95%, the purity can reach more than 98%, the mercury-free catalyst can completely replace the traditional mercury chloride catalyst, and the mercury-free catalyst is suitable for large-scale industrial production.)

1. The process for producing vinyl chloride by using mercury-free catalyst is characterized by comprising the following steps: s1, filling a catalyst; s2, activating a catalyst; s3. Synthesis of vinyl chloride, in particular

s1, catalyst filling: adding a support net with meshes not larger than 20mm at the bottom of a tube array of the tube array type converter, and paving 30-40mm of active carbon on the support net; then filling mercury-free catalyst in the tubes on the upper part of the activated carbon; then introducing nitrogen into the tube array to carry out pressurization and leakage detection, and then introducing hot nitrogen to dry the mercury-free catalyst for 24-48 h;

S2, catalyst activation: introducing 110-120 ℃ dried acetylene and hydrogen chloride gas into the converter after the filling is finished, wherein the opening of an inlet valve is 10 percent, continuously discharging acid for 12 hours at the bottom of the converter every 2 hours;

S3, synthesizing chloroethylene: controlling the molar ratio of acetylene to hydrogen chloride to be 1: 1.05-1.07, introducing mixed gas with the preheating temperature of more than 45 ℃ into a converter, culturing for 10-30 days, adjusting the introduction amount of acetylene gas according to the cooling capacity of the converter, and controlling the temperature to be between 90 and 120 ℃;

After the culture period is finished, the introduction amount of acetylene gas is adjusted according to the cooling capacity of the reactor, and the molar ratio of acetylene to hydrogen chloride is controlled to be 1: 1.05-1.07, and the reaction temperature is 120-180 ℃ to obtain the chloroethylene product.

2. The process for producing vinyl chloride under the catalysis of the mercury-free catalyst according to claim 1, wherein in the step S1, the mercury-free catalyst is filled in the tubular converter, and then the outer edge of the tubular converter is knocked by an explosion-proof tool to be vibrated and tamped.

3. The process for producing vinyl chloride under the catalysis of the mercury-free catalyst according to claim 1, wherein in the step S1, the filling of the mercury-free catalyst is completed within 2 hours after the mercury-free catalyst is opened to prevent the mercury-free catalyst from absorbing moisture.

4. the process for the catalytic production of vinyl chloride over a mercury-free catalyst as claimed in claim 1, wherein in the s1. catalyst loading, the temperature of hot nitrogen gas introduced into the converter is 50-60 ℃.

5. The process for the catalytic production of vinyl chloride with mercury-free catalyst as claimed in claim 1, wherein in the S3. synthesis of vinyl chloride, the reaction temperature of acetylene and hydrogen chloride is 145-150 ℃ after the end of the culture period.

6. The process for producing vinyl chloride under the catalysis of the mercury-free catalyst according to any one of claims 1 to 5, wherein the mercury-free catalyst comprises the following components in parts by weight: 1 part of antimony tetrachloride, 1-2 parts of polyvinylpyrrolidone, 3-6 parts of cuprous chloride, 2-5 parts of methyl rhenium trioxide, 2-4 parts of palladium dichloride (1, 5-cyclooctadiene), 1-2 parts of dibutyltin dilaurate and the balance of a carrier to 100 parts.

7. The process for the catalytic production of vinyl chloride over a mercury-free catalyst as claimed in claim 6, wherein the carrier is activated carbon.

8. The process for the catalytic production of vinyl chloride over a mercury-free catalyst as claimed in claim 6, wherein the support is carbon nanotubes.

The technical field is as follows:

The invention relates to a process for producing chloroethylene, in particular to a process for producing chloroethylene by using mercury-free catalyst.

Background art:

Vinyl chloride (abbreviated as VC) is a monomer for synthesizing polyvinyl chloride (abbreviated as PVC). The polyvinyl chloride resin is an important plastic raw material, is one of five general synthetic resins, has good physical and mechanical properties, and is widely applied to various fields in production and life. The production of vinyl chloride monomer is an important step in the polyvinyl chloride industry.

The synthesis process of chloroethylene mainly adopts acetylene method chloroethylene synthesis method. Acetylene and hydrogen chloride gas with certain purity are used as raw materials, mixed according to a certain proportion, added into a converter containing a catalyst, heated and reacted to generate vinyl chloride, and the reaction equation is as follows:

C₂H₂+HCl→C₂H₃Cl

at present, catalysts used for synthesizing vinyl chloride by an acetylene method are all mercury chloride catalysts. The catalyst used for synthesizing the chloroethylene is prepared by adsorbing mercuric chloride on an activated carbon carrier. Pure mercuric chloride does not play a role in catalyzing the synthesis reaction, pure activated carbon has a lower catalytic effect, and the mercuric chloride has strong catalytic activity after being adsorbed on the activated carbon. Although the yield and the selectivity of the mercury chloride catalyst used at present are higher, the mercury pollution is accompanied, and the environment is not friendly; in addition, the mercury reserves in China are small, most of mercury is imported, so that the mercury chloride catalyst is expensive, and the cost for producing vinyl chloride by using the mercury chloride catalyst is high.

Furthermore, it is known in practice that, in the synthesis process of vinyl chloride, the formulation of the catalyst and the method for producing vinyl chloride using the catalyst have a large influence on the yield and purity of vinyl chloride; in other words, the filling and using parameters of the catalyst, especially the catalytic temperature of the catalyst, are one of the key factors influencing the catalytic effect of the catalyst, and therefore, it is a difficult task that the research on a non-mercury catalyst formula and the process research for producing vinyl chloride by using the formula are long processes.

The invention content is as follows:

in order to solve the technical problems, the invention aims to provide a process for producing vinyl chloride by using mercury-free catalyst.

The invention is implemented by the following technical scheme: the process for producing vinyl chloride by using mercury-free catalyst catalysis comprises the following steps: s1, filling a catalyst; s2, activating a catalyst; s3. Synthesis of vinyl chloride, in particular

S1, catalyst filling: adding a support net with meshes not larger than 20mm at the bottom of a tube array of the tube array type converter, and paving 30-40mm of active carbon on the support net; then filling mercury-free catalyst in the tubes on the upper part of the activated carbon; then introducing nitrogen into the tube array to carry out pressurization and leakage detection, and then introducing hot nitrogen to dry the mercury-free catalyst for 24-48 h;

s2, catalyst activation: introducing 110-120 ℃ dried acetylene and hydrogen chloride gas into the converter after the filling is finished, wherein the opening of an inlet valve is 10 percent, continuously discharging acid for 12 hours at the bottom of the converter every 2 hours;

S3, synthesizing chloroethylene: controlling the molar ratio of acetylene to hydrogen chloride to be 1: 1.05-1.07, introducing the mixed gas with the preheating temperature of more than 45 ℃ into a converter, culturing for 10-30 days, adjusting the introduction amount of acetylene gas according to the cooling capacity of the converter, and controlling the temperature to be between 90 and 120 ℃;

after the culture period is finished, the introduction amount of acetylene gas is adjusted according to the cooling capacity of the reactor, and the molar ratio of acetylene to hydrogen chloride is controlled to be 1: 1.05-1.07, and the reaction temperature is 120-180 ℃ to obtain the chloroethylene product.

Further, in S1, catalyst filling, after filling the mercury-free catalyst in the tubular converter, knocking the outer edge of the tubular converter by using an explosion-proof tool, vibrating and tamping the mercury-free catalyst to prevent the mercury-free catalyst from bridging short circuit, and introducing mixed gas for a short time to reduce the conversion rate.

further, in the S1. catalyst filling process, in order to prevent the mercury-free catalyst from absorbing moisture, filling of the mercury-free catalyst is completed within 2 hours after the bag is opened.

Further, in the S1. catalyst filling process, the temperature of hot nitrogen introduced into the converter is 50-60 ℃.

Further, in the S3. synthesis of vinyl chloride, the reaction temperature of acetylene and hydrogen chloride after the end of the cultivation period is 145-150 ℃.

Further, the mercury-free catalyst comprises the following components in parts by weight: 1 part of antimony tetrachloride, 1-2 parts of polyvinylpyrrolidone, 3-6 parts of cuprous chloride, 2-5 parts of methyl rhenium trioxide, 2-4 parts of palladium dichloride (1, 5-cyclooctadiene), 1-2 parts of dibutyltin dilaurate and the balance of a carrier to 100 parts.

The mercury-free catalyst can be prepared by the following preparation method: firstly, dissolving antimony tetrachloride and polyvinylpyrrolidone in water; then, methyl rhenium trioxide, (1, 5-cyclooctadiene) palladium dichloride and dibutyltin dilaurate are added under stirring to prepare a first solution; dissolving cuprous chloride in ethanol to prepare a second solution, finally immersing the carrier in the first solution, carrying out ultrasonic vibration, and dropwise adding the second solution; and finally, filtering, and calcining a filter cake at high temperature to obtain the mercury-free catalyst.

Further, the carrier is activated carbon.

Further, the carrier is a carbon nanotube.

the invention has the advantages that: the mercury-free catalyst disclosed by the invention is environment-friendly, and avoids the pollution of mercury to the environment when the traditional mercury chloride catalyst is used for producing vinyl chloride; in addition, compared with the traditional mercury chloride catalyst, the mercury-free catalyst has lower price and low cost and is more suitable for sustainable development. The mercury-free catalyst disclosed by the invention is simple in process, convenient to operate and strong in pertinence, and when the mercury-free catalyst is used for producing vinyl chloride, the catalytic activity is high, the yield of the produced vinyl chloride is high, the purity is good, the yield can reach more than 95%, the purity can reach more than 98%, the mercury-free catalyst can completely replace the traditional mercury chloride catalyst, and the mercury-free catalyst is suitable for large-scale industrial production.

The specific implementation mode is as follows:

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.