Process for synthesizing vinyl chloride through micro-channel reactor
By using microchannel reactors and liquid mercury-free catalysts in vinyl chloride synthesis process, the problems of mercury pollution and high cost in traditional processes are solved, and vinyl chloride is efficiently synthesized under mild conditions, reducing side reaction risks and thermal energy use quantity.
Patent Information
- Application Number
- CN202411460182.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-18
- Publication Date
- 2025-01-03
AI Technical Summary
The mercury chloride catalyst used in the traditional vinyl chloride synthesis process causes environmental pollution, the cost of precious metal catalysts is high, and the active components of non-precious metal catalysts are severely lost, and the reaction heat is difficult to remove, surface flying temperature, local hot spots, and catalyst carbon deposits. .
Using a microchannel reactor and liquid mercury-free catalyst, acetylene and raw materials are mixed and heated through a jet mixer, and efficient reaction is carried out in the microchannel reactor, and impurities in the old liquid catalyst are treated with gas-liquid separation and reduced pressure distillation tower. gas.
Reaction under milder conditions reduces heat and substance accumulation, solves mercury pollution problems, and improves safety performance and cost-effectiveness.
Smart Images
Figure CN119236825A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of vinyl chloride synthesis, in particular to a process for synthesizing vinyl chloride through a microchannel reactor. Background Art
[0002] The industrial synthesis process of vinyl chloride is mainly divided into acetylene method and ethylene method. In China, the coal-based acetylene method is the mainstream process for vinyl chloride synthesis, but the mercuric chloride catalyst used in this process will cause serious pollution to the environment, limiting its sustainable and healthy development. Although the industry has reduced the loss and emission of mercury to a certain extent by reducing the mercury content in the catalyst and strengthening the solid mercury in recent years, it has not been able to fundamentally solve the mercury pollution problem.
[0003] The traditional acetylene process is a gas-solid phase reaction process, and the catalyst is a solid-supported catalyst. In the research of gas-solid phase mercury-free catalysts, precious metal catalysts have high catalytic activity, but the cost is high. Although non-precious metal catalysts are cheap and economical, there is a problem of large loss of active components. In addition, the traditional acetylene process has technical problems such as difficulty in removing reaction heat, surface temperature rise, local hot spots, and catalyst carbon deposition. Summary of the invention
[0004] In view of the deficiencies of the prior art, the present invention provides a process for synthesizing vinyl chloride through a microchannel reactor, which solves the problems raised by the above-mentioned background technology.
[0005] To achieve the above object, the present invention is implemented by the following technical scheme: A process for synthesizing vinyl chloride by a microchannel reactor comprises the following steps: Step 1: pressurize the raw material using a pressurizing device, and bring acetylene into the preheating device through a jet mixer; Step 2: controlling the molar ratio of the raw material to acetylene to be 1.05-1.1:1, and then heating the mixed mixture to 90-160° C. through a preheating device; Step 3, injecting the heated mixture and the liquid catalyst into a microchannel reactor, wherein the mixture reacts efficiently in the microchannel reactor under the action of the liquid catalyst to generate vinyl chloride; Step 4: inject the generated vinyl chloride and liquid catalyst into a cooling device to cool down to 130-150° C., and then separate the gas and liquid through a gas-liquid separation device, the separated liquid catalyst is recycled, and the vinyl chloride gas exits the device; Step 5: After the liquid catalyst has been used multiple times, a new liquid catalyst is replaced and the old liquid catalyst is disposed of.
[0006] Preferably, the liquid catalyst is a liquid mercury-free catalyst.
[0007] Preferably, the old liquid catalyst is treated by: Step 31, injecting the old liquid catalyst into the residual liquid storage tank, and transporting it to the vacuum distillation tower through the residual liquid pump; Step 32: Use a vacuum pump to reduce the pressure and remove the impurity gas in the old liquid catalyst from the top of the vacuum distillation tower.
[0008] Beneficial Effects The present invention provides a process for synthesizing vinyl chloride by a microchannel reactor. Compared with the prior art, it has the following beneficial effects: 1. The process of synthesizing vinyl chloride by microchannel reactor pressurizes the raw materials and then introduces acetylene into the system through a jet mixer, effectively mixing the two raw materials and increasing the pressure of the mixed raw materials, thus solving the safety problem caused by pressurizing acetylene alone.
[0009] 2. The process of synthesizing vinyl chloride by microchannel reactor can rapidly carry out the reaction under milder conditions by setting up microchannel reactor, while reducing the accumulation of heat and substances and the risk of side reactions. It has the advantages of high heat and mass transfer efficiency, precise fluid control, uniform reaction conditions and good safety performance.
[0010] 3. The process of synthesizing vinyl chloride by means of a microchannel reactor, by setting up a liquid mercury-free catalyst, not only saves costs, but also solves the mercury pollution problem in the existing vinyl chloride production. BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION
[0012] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0013] See also Figure 1 The present invention provides a technical solution: a process for synthesizing vinyl chloride by a microchannel reactor, comprising the following steps: Step 1: pressurize the raw material using a pressurizing device, and bring acetylene into the preheating device through a jet mixer; Step 2: controlling the molar ratio of the raw material to acetylene to be 1.05-1.1:1, and then heating the mixed mixture to 90-160° C. through a preheating device; Step 3, injecting the heated mixture and the liquid catalyst into a microchannel reactor, wherein the mixture reacts efficiently in the microchannel reactor under the action of the liquid catalyst to generate vinyl chloride; Step 4: inject the generated vinyl chloride and liquid catalyst into a cooling device to cool down to 130-150° C., and then separate the gas and liquid through a gas-liquid separation device, the separated liquid catalyst is recycled, and the vinyl chloride gas exits the device; Step 5: After the liquid catalyst has been used multiple times, a new liquid catalyst is replaced and the old liquid catalyst is disposed of; The raw materials are hydrogen chloride, ethylene dichloride, etc., which are not limited to the above raw materials, and different boosting equipment can be used to boost the pressure according to the different raw materials, such as hydrogen chloride using a gas compressor to boost the pressure to 0.16MPa, and ethylene dichloride using a liquid booster pump to boost the pressure to 0.6MPa. In this way, acetylene is brought into the system by passing the raw materials through a jet mixer after pressurization, effectively mixing the two raw materials, and achieving the purpose of boosting the mixed raw materials, solving the safety problem caused by pressurizing acetylene alone, and by setting a microchannel reactor, the reaction can be carried out rapidly under milder conditions, while reducing the accumulation of heat and materials, and reducing the risk of side reactions. It has the advantages of high heat and mass transfer efficiency, precise fluid control, uniformity of reaction conditions, and good safety performance.
[0014] Furthermore, the liquid catalyst is a liquid mercury-free catalyst, which not only solves the mercury pollution problem in the existing vinyl chloride production, but also saves costs.
[0015] Furthermore, the old liquid catalyst is treated by: Step 31, injecting the old liquid catalyst into the residual liquid storage tank, and transporting it to the vacuum distillation tower through the residual liquid pump; Step 32, using a vacuum pump to reduce pressure and remove impurity gases in the old liquid catalyst from the top of the vacuum distillation tower; In this way, the residual chemical components in the old liquid catalyst have different volatilities at different temperatures and pressures, and the impurity gases in the old liquid catalyst are removed in a vacuum distillation tower under the conditions of slight negative pressure and normal temperature. The conditions of slight negative pressure and normal temperature make the production safer, more stable, easier to control, and reduce the use of thermal energy.
[0016] Meanwhile, the contents not described in detail in this specification belong to the prior art known to those skilled in the art.
[0017] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions. The sentence "includes an element defined by ... does not exclude the existence of other identical elements in the process, method, article or device including the element".
[0018] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. A process for synthesizing vinyl chloride by a microchannel reactor, characterized in that: The following steps are involved: Step 1: pressurize the raw material using a pressurizing device, and bring acetylene into the preheating device through a jet mixer; Step 2: controlling the molar ratio of the raw material to acetylene to be 1.05-1.1:1, and then heating the mixed mixture to 90-160° C. through a preheating device; Step 3, injecting the heated mixture and the liquid catalyst into a microchannel reactor, wherein the mixture reacts efficiently in the microchannel reactor under the action of the liquid catalyst to generate vinyl chloride; Step 4: inject the generated vinyl chloride and liquid catalyst into a cooling device to cool down to 130-150° C., and then separate the gas and liquid through a gas-liquid separation device, the separated liquid catalyst is recycled, and the vinyl chloride gas exits the device; Step 5: After the liquid catalyst has been used multiple times, a new liquid catalyst is replaced and the old liquid catalyst is disposed of.
2. A process for synthesizing vinyl chloride by a microchannel reactor according to claim 1, characterized in that: The liquid catalyst is a liquid mercury-free catalyst.
3. A process for synthesizing vinyl chloride by a microchannel reactor according to claim 2, characterized in that: The method for treating the old liquid catalyst is as follows: Step 31, injecting the old liquid catalyst into the residual liquid storage tank, and transporting it to the vacuum distillation tower through the residual liquid pump; Step 32: Use a vacuum pump to reduce the pressure and remove the impurity gas in the old liquid catalyst from the top of the vacuum distillation tower.