A process, apparatus and system for the production of methane chlorides

Abstract

The application provides a production method, device and system of methane chloride. The method comprises the following steps: step 1), a substitution reaction treatment is performed on a raw material system comprising chlorine and methyl chloride to obtain high-temperature reaction gas; step 2), a first-stage dust removal treatment is performed on the high-temperature reaction gas by using a first-stage washing liquid to obtain first-stage reaction gas and solid-containing slurry; step 3), a second-stage washing treatment is performed on the first-stage reaction gas by using a second-stage washing liquid to obtain gaseous methane chloride product and recovered washing liquid; a first part of the recovered washing liquid is used as the first-stage washing liquid to participate in the first-stage dust removal treatment; and step 4), a flash treatment is performed on the solid-containing slurry and a second part of the recovered washing liquid to obtain flash liquid and solid-liquid residual components; and the flash liquid is used as the second-stage washing liquid to participate in the second-stage washing treatment. The method optimizes the anti-blocking process, and can improve the operation stability and long-period continuous production capacity.

Description

Technical Field

[0001] This invention relates to the field of chemical technology, and in particular to a method, apparatus and system for producing methane chloride. Background Technology

[0002] Chlorinated methane mainly includes products such as chloromethane, dichloromethane, trichloromethane, and carbon tetrachloride. It is an important basic organochlorine raw material, widely used in refrigerants, organosilicon, pharmaceuticals, pesticides, fine chemicals, and electronic chemicals. With the development of downstream organosilicon, new energy materials, and fine chemical industries, the market has placed higher demands on the yield, quality, and operational stability of chlorinated methane products.

[0003] Currently, industrial production of methane chloride mainly employs thermal chlorination or photochlorination processes. These processes involve continuously chlorinating methane, chlorine, and recycled materials by feeding them into the reaction system. The reaction products are then separated and recovered through units such as quenching, absorption, distillation, and recycling. However, during long-term operation, impurities such as high-boiling-point substances and inorganic salt particles carried in the reaction stream tend to deposit on the inner walls of equipment, heat exchange surfaces, and dead corners of pipelines, gradually forming scale or blockages. Blockages not only increase fluid resistance, reduce heat exchange efficiency, and raise equipment pressure drop, but can also cause localized overheating, uneven material distribution, and frequent shutdowns for cleaning, severely impacting the continuous and stable operation of the plant and its economic benefits.

[0004] Therefore, how to further optimize the anti-clogging process in the production of methane chloride and improve operational stability and long-term continuous production capacity remains a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] This invention provides a method for producing methane chloride, which optimizes the anti-clogging process and improves operational stability and long-cycle continuous production capacity.

[0006] This invention provides a production apparatus for methane chloride, which optimizes anti-clogging performance and improves operational stability and long-cycle continuous production capacity.

[0007] This invention provides a production system for methane chloride that optimizes anti-clogging performance, improves operational stability, and enhances long-cycle continuous production capacity.

[0008] In a first aspect, the present invention provides a method for producing methane chloride, comprising the following steps:

[0009] Step 1): The raw material system, including chlorine and chloromethane, is subjected to a substitution reaction to obtain a high-temperature reaction gas;

[0010] Step 2): The high-temperature reaction gas is subjected to primary dust removal treatment using primary washing liquid to obtain primary reaction gas and solid slurry;

[0011] Step 3): The primary reaction gas is subjected to secondary washing treatment using secondary washing liquid to obtain gaseous methane chloride product and recovered washing liquid; the recovered washing liquid in the first part is used as the primary washing liquid in the primary dust removal treatment;

[0012] Step 4): The solid-containing slurry and the recovered washing liquid from the second part are subjected to flash evaporation to obtain flash clear liquid and solid-liquid residue components; the flash clear liquid is used as the secondary washing liquid in the secondary washing process.

[0013] In one possible embodiment, the secondary washing process includes: performing a primary washing process on the primary reaction gas using a primary washing liquid to obtain an intermediate reaction gas and a primary recovery washing liquid;

[0014] The intermediate reaction gas is subjected to deep washing treatment using a deep washing solution to obtain the gaseous methane chloride product and the deep recovery washing solution.

[0015] The secondary washing solution includes the primary washing solution and the deep washing solution, and the recycled washing solution further includes the primary recycled washing solution and the deep recycled washing solution;

[0016] The primary washing solution also includes the remaining portion of the recycled washing solution, and the deep washing solution includes the flash-evaporated clarified liquid.

[0017] In one possible embodiment, the process further includes condensing the gaseous methane chloride product to obtain a liquid methane chloride product and a non-condensable gas; returning a portion of the liquid methane chloride product as a secondary washing liquid to participate in the secondary washing process; and / or,

[0018] It also includes separating the remaining portion of the liquid-phase methane chloride product to obtain refined methane chloride product and chloromethane recovery material; the chloromethane recovery material is then returned to participate in the substitution reaction process.

[0019] In one possible embodiment, the solid-liquid residual components are further subjected to solid-liquid separation treatment to obtain a clear separation liquid and a sedimentation phase, and the clear separation liquid is used as the secondary washing liquid in the secondary washing treatment;

[0020] The separated sediment phase is concentrated to obtain a concentrated liquid phase and a concentrated solid phase. The concentrated liquid phase is used as the secondary washing liquid in the secondary washing process; and / or,

[0021] It also includes performing waste heat recovery treatment on the high-temperature reaction gas to obtain a low-temperature reaction gas, the temperature of which is below 250°C; and subjecting the low-temperature reaction gas to the primary dust removal treatment.

[0022] In one possible embodiment, the temperature of the primary reaction gas is below 180°C; and / or,

[0023] The operating pressure during the flash evaporation process is 0.005-0.5 MPaG; the operating pressure during the concentration process is 0.05-0.1 MPaG.

[0024] In a second aspect, the present invention provides a production apparatus for methane chloride, used to implement the method described in any one of the first aspects of the present invention, including a reaction device, a primary dust removal device, a secondary washing device, and a flash evaporation device;

[0025] The reaction equipment includes a raw material system inlet and a high-temperature reaction gas outlet;

[0026] The primary dust removal equipment includes a high-temperature reaction gas inlet, a primary washing liquid inlet, a primary reaction gas outlet, and a solid slurry-containing outlet;

[0027] The secondary washing equipment includes a primary reaction gas inlet, a secondary washing liquid inlet, a recovered washing liquid outlet, and a gaseous methane chloride product outlet;

[0028] The flash evaporation equipment includes a solid slurry inlet, a flash evaporation recovery washing liquid inlet, a flash evaporation clear liquid outlet, and a solid-liquid residual component outlet;

[0029] The high-temperature reaction gas outlet and the high-temperature reaction gas inlet are connected;

[0030] The primary reactant gas outlet and the primary reactant gas inlet are connected;

[0031] The recovered washing liquid outlet is connected to the primary washing liquid inlet and the flash-evaporated recovered washing liquid inlet, respectively.

[0032] The solid slurry outlet and the solid slurry inlet are connected;

[0033] The secondary washing liquid inlet and the flash-evaporated clear liquid outlet are connected.

[0034] In one possible embodiment, the secondary washing device further includes a primary washing section and a deep washing section; wherein,

[0035] The primary reaction gas inlet and the recovered washing liquid outlet are located in the primary washing section, which also includes a primary washing liquid inlet and an intermediate reaction gas outlet.

[0036] The gaseous methane chloride product outlet is located in the deep scrubbing section, which also includes a deep scrubbing liquid inlet, an intermediate reaction gas inlet, and a deep recovery scrubbing liquid outlet.

[0037] The primary washing liquid inlet and the deep recovery washing liquid outlet and the recovery washing liquid outlet are respectively connected; the intermediate reaction gas inlet and the intermediate reaction gas outlet are connected.

[0038] In one possible embodiment, it also includes a solid-liquid separation device, a concentration device, and a waste heat recovery device;

[0039] The solid-liquid separation equipment includes a solid-liquid residual component inlet, a separated clear liquid outlet, and a separated settled phase outlet;

[0040] The concentration equipment includes a separation sedimentation phase inlet, a concentrated liquid phase outlet, and a concentrated solid phase outlet;

[0041] The solid-liquid residual component outlet and the solid-liquid residual component inlet are connected;

[0042] The separated clear liquid outlet and the concentrated liquid phase outlet are respectively connected to the secondary washing liquid inlet;

[0043] The high-temperature reaction gas outlet is connected to the high-temperature reaction gas inlet via the waste heat recovery equipment.

[0044] In one possible embodiment, the device further includes a condensation unit and a separation unit, the condensation unit comprising a gaseous methane chloride product inlet, a non-condensable gas outlet, and a liquid methane chloride product outlet;

[0045] The separation equipment includes a chloromethane recovery feed outlet, a refined methane chloride product outlet, and a liquid-phase methane chloride product inlet.

[0046] The liquid-phase methane chloride product outlet is connected to both the secondary washing liquid inlet and the liquid-phase methane chloride product inlet.

[0047] The outlet of the chloromethane recovery material is connected to the inlet of the raw material system.

[0048] Thirdly, the present invention provides a production system for methane chloride, including the apparatus described in any of the second aspects of the present invention, and further including a raw material supply device and a non-condensable gas recovery device.

[0049] This invention provides a method, apparatus, and system for producing methane chloride. First, a substitution reaction generates a high-temperature reaction gas containing methane chloride. Then, a primary dust removal process ensures sufficient contact between solid particles and liquid droplets in the reaction gas, causing them to agglomerate into larger particles and initially separate from the reaction gas. Further, a secondary washing process washes, absorbs, and dissolves the target product, high-boiling-point impurities, and small particulate solids, achieving separation of methane chloride from other components. Simultaneously, the recovered washing liquid generated during the washing process is diverted for reuse; a portion is returned to the primary dust removal process, improving the washing liquid utilization efficiency. In addition, the solid-containing slurry and another portion of the recovered washing liquid are flash-distilled to obtain a clear flash-distilled liquid containing effective washing components, which is then returned as secondary washing liquid, achieving the recycling and regeneration of the washing medium. This not only reduces washing liquid consumption and wastewater discharge in traditional processes but also optimizes the anti-clogging process, contributing to improved long-term stability and resource utilization efficiency of the production process. Attached Figure Description

[0050] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0051] Figure 1 The process flow diagram provided for this invention;

[0052] Figure 2 This is a schematic diagram of the device provided by the present invention.

[0053] The accompanying drawings have illustrated specific embodiments of the invention, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the invention in any way, but rather to illustrate the concept of the invention to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0054] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0055] Chlorinated methane (including chloromethane, dichloromethane, trichloromethane, and carbon tetrachloride) are important basic chlorinated organic chemical products, widely used in the synthesis of organosilicon monomers, refrigerant intermediates, pharmaceutical and pesticide synthesis, and fine chemical processing.

[0056] In actual industrial operation, such reaction systems are highly prone to scaling and clogging. Existing anti-clogging technologies mostly employ methods such as enhanced filtration, periodic online cleaning, or localized optimization of heat exchange structures. However, since the clogging process is influenced by multiple factors simultaneously, these measures are unlikely to fundamentally break the deposition chain. They often only delay but cannot fundamentally inhibit clogging, and problems such as short operating cycles and frequent maintenance still exist.

[0057] This invention reveals that the fundamental reason for the difficulty in resolving blockages lies in the presence of a multiphase impurity system in the reaction system, including high-temperature free radical reactions, carbon black particles generated from side reactions, and high-boiling-point polychlorinated byproducts. On the one hand, carbon black and fine particles have high specific surface area and strong adsorption properties, easily forming initial deposition nuclei on the surfaces of heat exchangers, pipelines, and internal tower components. On the other hand, polychlorinated high-boiling-point substances are prone to liquid film precipitation under cooling and local concentration conditions, and synergistic adhesion with particles, forming a tar-like deposition layer with a certain degree of viscoelasticity.

[0058] To address the aforementioned problems, this invention systematically breaks down the fundamental mechanism of blockage formation and proposes a multi-stage synergistic anti-blockage path design. Its core lies in no longer treating blockage as a simple scaling problem, but rather establishing a dust collection, circulating washing, and flash evaporation dynamic discharge regeneration system. This weakens the conditions for particle adhesion in the early stages of the reaction, reduces the driving force for the elution of high-boiling components during mass transfer, and continuously breaks the accumulation path of solid and heavy components at the end of the system, thereby blocking the entire blockage formation process.

[0059] In a first aspect, the present invention provides a method for producing methane chloride, comprising the following steps:

[0060] Step 1): The raw material system, including chlorine and chloromethane, is subjected to a substitution reaction to obtain a high-temperature reaction gas;

[0061] Step 2): Use primary washing liquid to perform primary dust removal treatment on the high-temperature reaction gas to obtain primary reaction gas and solid slurry;

[0062] Step 3): The primary reaction gas is subjected to secondary washing treatment using secondary washing liquid to obtain gaseous methane chloride product and recovered washing liquid; the first part of the recovered washing liquid is used as primary washing liquid in primary dust removal treatment;

[0063] Step 4): Flash evaporate the solid slurry and the second-part recovered washing liquid to obtain flash clear liquid and solid-liquid residue components; use the flash clear liquid as secondary washing liquid in secondary washing treatment.

[0064] In this invention, firstly, in step 1), chlorine reacts with chloromethane to produce methane chloride. At the same time, due to the high reaction temperature, the resulting high-temperature reaction gas contains not only the target product, but also unreacted raw materials, chlorination byproducts, and some high-boiling condensation components.

[0065] Subsequently, in step 2), the high-temperature reaction gas is treated with primary dust removal using primary washing liquid. Through full contact between gas and liquid, solid particles and easily condensable impurities in the reaction gas are preferentially captured by the washing liquid and form a solid slurry. At the same time, the remaining solid particles are dispersed to prevent scaling or direct entry into subsequent washing equipment, thereby reducing the risk of deposition and blockage inside pipelines and equipment from the source.

[0066] Furthermore, in step 3), a secondary washing liquid is used to perform a secondary washing of the primary reaction gas to further remove residual impurities and condensable components, thereby obtaining a gaseous methane chloride product. Simultaneously, the recovered washing liquid generated from the secondary washing is used for primary dust removal and subsequent flash evaporation treatment, ensuring that the washing liquid continuously maintains its ability to carry and disperse impurities, preventing impurities from circulating and accumulating within the system.

[0067] In step 4), the solid-containing slurry generated from the primary dust removal process is flash-distilled together with a portion of the recovered washing liquid. Utilizing the differences in volatility of the different components, the volatile liquid phase components entrained in the slurry are separated from the solid impurities, yielding a clear flash-distilled liquid. This clear flash-distilled liquid is then reused as the secondary washing liquid in the washing process, ensuring its continuous circulation and renewal. Simultaneously, the concentrated solid residue is discharged, reducing the long-term accumulation of solid impurities within the system.

[0068] Through the above steps, this solution employs a staged treatment approach—front-end dust collection, mid-stage washing and purification, and rear-end flash evaporation regeneration—to effectively separate high-boiling-point substances, solid impurities, and easily condensable components before they enter critical equipment, reducing the risk of internal deposition and blockage. Simultaneously, by regulating the circulation of the washing liquid, the system's impurity-carrying capacity is maintained, preventing shortened operating cycles due to impurity accumulation. Therefore, this solution improves the anti-clogging performance of methane chloride production units, reduces the frequency of shutdowns for cleaning, and enhances the unit's long-term continuous operation capability and industrial production stability.

[0069] In one possible embodiment, the secondary washing process includes: performing a primary washing process on the primary reaction gas using a primary washing liquid to obtain an intermediate reaction gas and a primary recovery washing liquid;

[0070] The intermediate reaction gas is deeply washed with a deep washing solution to obtain gaseous methane chloride product and deep recovery washing solution.

[0071] Secondary washing solutions include primary washing solutions and deep washing solutions, and recycled washing solutions also include primary recycled washing solutions and deep recycled washing solutions;

[0072] The primary washing solution also includes the remaining recycled washing solution, and the deep washing solution includes flash-evaporated clarified liquid.

[0073] In this embodiment, since the reaction gas after primary dust removal may still contain trace amounts of high-boiling byproducts, unreacted components, and small particulate solid impurities, there may be problems such as concentrated washing load and rapid deterioration of the washing liquid. Therefore, this solution first uses a primary washing liquid to perform primary washing treatment on the primary reaction gas, which further transfers some soluble impurities, high-boiling components, and small particulate solid impurities in the reaction gas to the liquid phase, reducing the impurity load in the subsequent deep washing process, and obtaining a relatively clean intermediate reaction gas and primary recovered washing liquid. At the same time, the recovered washing liquid, including the primary recovered washing liquid and the deep recovered washing liquid, is recycled to further improve the washing liquid utilization efficiency.

[0074] Subsequently, the intermediate reaction gas is subjected to deep washing with a deep washing liquid. After primary washing, the impurity content in the gas entering the deep washing stage is reduced, and the deep washing liquid can more effectively improve the collection efficiency of the target product. In this scheme, the clarified liquid obtained from flash evaporation is used as the deep washing liquid. After front-end impurity separation, this clarified liquid has a low solid impurity content, which can meet the requirements of deep washing treatment.

[0075] This embodiment uses a gradient purification method of primary washing and deep washing, so that different washing stages can respectively undertake the functions of impurity removal and product capture, thereby achieving a reasonable distribution of washing load; at the same time, the recycling and graded utilization of primary recovered washing liquid, deep recovered washing liquid and flash evaporation clear liquid can improve efficiency.

[0076] In one possible embodiment, the gaseous methane chloride product is further condensed to obtain a liquid methane chloride product and a non-condensable gas; a portion of the liquid methane chloride product is returned as a secondary washing liquid to participate in the deep washing process.

[0077] In this embodiment, by condensing the gaseous methane chloride product and returning a portion of the liquid methane chloride product as a washing medium to participate in the washing process, product recovery and washing enhancement are coupled. The gaseous methane chloride product after washing still contains some condensable components. Condensation treatment can transform the methane chloride in the gaseous phase from a gaseous state to a liquid state, thereby separating non-condensable gases and reducing the load on subsequent product processing.

[0078] Furthermore, a portion of the condensed liquid-phase methane chloride product is returned to the washing process as a secondary washing liquid. Since the returned liquid-phase methane chloride product has undergone multi-stage separation, the content of solid impurities and high-boiling deposits is low. Using it as a washing medium can reduce the accumulation of impurities in the washing system, reduce the need to replenish fresh washing medium, and enhance the washing effect by utilizing the product's own solubility properties.

[0079] In this invention, the liquid-phase methane chloride product can participate in both primary and deep washing processes. Combined with the washing liquid recycling process of the above embodiments, using the liquid-phase methane chloride product in deep washing allows for the gradual enrichment of impurities in the washing liquid. Specifically, the impurity content increases progressively from the deep washing liquid containing the liquid-phase methane chloride product and flash distillate, to the primary washing liquid containing both primary and deep recycled washing liquid, and finally to the recycled washing liquid. This process can distribute the processing load and further improve anti-clogging performance.

[0080] In one possible embodiment, the process further includes separating the remaining liquid-phase methane chloride product to obtain purified methane chloride product and chloromethane recovery material; the chloromethane recovery material is then returned to participate in the substitution reaction process.

[0081] In this embodiment, since a certain proportion of chloromethane is usually required in the reaction system during the substitution reaction of chlorine and chloromethane to promote the reaction and improve the selectivity of the target product, the gaseous product after the reaction may still contain unreacted chloromethane components. Therefore, this method separates the remaining liquid-phase methane chloride product to effectively separate the methane chloride product components from the unreacted chloromethane components in the liquid-phase mixture, obtaining purified methane chloride product and chloromethane recovery material, thereby improving material utilization efficiency.

[0082] In one possible embodiment, the process further includes solid-liquid separation of the solid and liquid residual components to obtain a clear liquid and a sedimented phase, with the clear liquid used as a secondary washing liquid in the secondary washing process; and concentration of the sedimented phase to obtain a concentrated liquid phase and a concentrated solid phase, with the concentrated liquid phase used as a secondary washing liquid in the secondary washing process.

[0083] In this embodiment, since the solid-liquid residue obtained from flash evaporation may still contain a certain amount of liquid medium, dissolved substances and solid particulate impurities, this solution first performs solid-liquid separation treatment on the solid-liquid residue to separate the fluid liquid component from the solid sediment. The separated clear liquid still contains a certain amount of usable liquid component, which is returned as a secondary washing liquid to participate in the washing process, thereby improving the utilization efficiency of the washing liquid.

[0084] Furthermore, the separated sediment phase is concentrated to further release or enrich the remaining recoverable liquid phase components, resulting in a concentrated liquid phase and a concentrated solid phase. The concentrated liquid phase is returned as a secondary washing liquid, which can further recover the effective liquid phase components in the sediment phase and enhance the liquid phase replenishment capacity during the washing process. The concentrated solid phase is discharged as the final solid residue, achieving centralized removal of impurities and improving continuous operation capability and long-term stability.

[0085] In this invention, the separated clear liquid and concentrated liquid phase can be used as supplementary components of the secondary washing liquid for primary and deep washing processes, depending on the actual needs of the washing process. Since the separated clear liquid and concentrated liquid phase have undergone solid-liquid separation and concentration, reducing the content of solid particles and non-volatile impurities, they possess good fluidity and washing ability. Returning them to the washing process can further improve the utilization efficiency of the washing liquid.

[0086] When used for deep washing, the separated clear liquid or concentrated liquid phase with low impurity content can be used as a component of the deep washing liquid, which helps maintain the cleanliness of the deep washing liquid. When used in the primary washing stage, its ability to carry solid particles and high-boiling components can be utilized to enhance the front-end impurity removal effect. Therefore, the composition of the washing liquid can be adjusted according to the composition of the reaction gas, impurity load, and operating conditions to improve the equipment's anti-clogging performance and long-term continuous operation capability.

[0087] In one possible embodiment, the temperature of the primary reaction gas is below 180°C.

[0088] In this embodiment, controlling the temperature of the primary reaction gas helps reduce the uneven gas-liquid mass transfer caused by local overheating in the subsequent washing equipment, making it easier for solid particles and high-boiling substances to transfer with the washing liquid, and reducing the possibility of them depositing on the surface of pipes, tower internals and heat exchange components.

[0089] In one possible embodiment, the operating pressure is 0.005-0.5 MPaG during flash evaporation and 0.05-0.1 MPaG during concentration.

[0090] In this embodiment, by reducing the flash evaporation pressure, a volatility difference is created between the volatile components and non-volatile solid impurities in the recovered washing liquid and solid-containing slurry. This allows the recoverable liquid components to preferentially transfer to the flash clarified liquid, while non-volatile components such as solid particles and high-boiling residues are concentrated and separated. Using an operating pressure of 0.05-0.1 MPaG in the concentration process facilitates further removal of volatile liquid components from the concentrate, enabling the recovery of recyclable liquid components and promoting the enrichment and discharge of solid impurities.

[0091] In a second aspect, the present invention provides a production apparatus for methane chloride, used to implement the method of any one of the first aspects of the present invention, including a reaction apparatus, a primary dust removal apparatus, a secondary washing apparatus, and a flash evaporation apparatus;

[0092] The reaction equipment includes a raw material system inlet and a high-temperature reaction gas outlet;

[0093] The primary dust removal equipment includes a high-temperature reaction gas inlet, a primary washing liquid inlet, a primary reaction gas outlet, and an outlet containing solid slurry.

[0094] The secondary scrubbing equipment includes a primary reaction gas inlet, a secondary scrubbing liquid inlet, a recovered scrubbing liquid outlet, and a gaseous methane chloride product outlet;

[0095] The flash evaporation equipment includes a solid slurry inlet, a flash evaporation recovery washing liquid inlet, a flash evaporation clear liquid outlet, and a solid-liquid residual component outlet;

[0096] The high-temperature reaction gas outlet and the high-temperature reaction gas inlet are connected; the primary reaction gas outlet and the primary reaction gas inlet are connected; the recovered washing liquid outlet is connected to the primary washing liquid inlet and the flash evaporation recovered washing liquid inlet, respectively; the solid slurry outlet and the solid slurry inlet are connected; the secondary washing liquid inlet and the flash evaporation clear liquid outlet are connected.

[0097] In this invention, the raw material system enters the reaction equipment through the raw material system inlet to undergo a substitution reaction, generating a high-temperature reaction gas containing methane chloride. This gas is then discharged from the high-temperature reaction gas outlet and enters the high-temperature reaction gas inlet of the primary dust removal equipment. Simultaneously, the primary washing liquid enters the primary dust removal equipment through the primary washing liquid inlet, causing solid particles, high-boiling byproducts, and easily condensable impurities in the high-temperature reaction gas to be captured by the primary washing liquid, forming a solid-containing slurry, which is then discharged from the solid-containing slurry outlet. The primary reaction gas after impurity removal is then discharged from the primary reaction gas outlet.

[0098] The primary reaction gas enters the primary reaction gas inlet of the secondary scrubbing equipment and comes into contact with the secondary scrubbing liquid entering through the secondary scrubbing liquid inlet. Residual impurities and some condensable components are absorbed by the scrubbing liquid, simultaneously yielding gaseous methane chloride product, which is discharged through the gaseous methane chloride product outlet. The recovered scrubbing liquid generated during the secondary scrubbing process is discharged through the recovered scrubbing liquid outlet. A portion of this liquid is returned to the primary scrubbing liquid inlet for use in the primary dust removal process; the other portion enters the flash evaporation equipment through the flash evaporation recovered scrubbing liquid inlet.

[0099] Simultaneously, the solid-containing slurry generated during the primary dust removal process enters the solid-containing slurry inlet of the flash evaporator through the solid-containing slurry outlet, and undergoes flash evaporation treatment together with the recovered washing liquid entering the flash evaporator. This process separates the volatile liquid phase components from the non-volatile solid impurities, yielding recyclable flash evaporation clarified liquid and solid-liquid residue components. The flash evaporation clarified liquid is discharged through the flash evaporation clarified liquid outlet and enters the secondary washing liquid inlet of the secondary washing equipment to participate in the washing process as secondary washing liquid; the solid-liquid residue components are discharged through the solid-liquid residue component outlet, achieving centralized removal of solid impurities.

[0100] In one specific embodiment, the reaction equipment can be a reactor suitable for the gas-phase substitution reaction of methane chloride, such as a tubular reactor, a tower reactor, or a reaction device with gas mixing and temperature control structures, to achieve thorough mixing and reaction of chlorine and chloromethane.

[0101] In one specific embodiment, the primary dust removal equipment can be a gas-liquid contact dust removal device, preferably a venturi dust collector. Venturi tubes do not have packing or tray structures, so they are not easily clogged by the deposition of high-boiling substances and solid particles. Through the high-speed shearing action of the airflow on the droplets and the inertial collision between the particles and the droplets, solid particles, high-boiling byproducts and easily condensable components are captured by the droplets and enter the liquid phase with the washing liquid to form a solid-containing slurry.

[0102] In one specific embodiment, the secondary scrubbing equipment can be a single-stage or multi-stage gas-liquid scrubbing equipment, such as a spray tower, packed tower, plate scrubbing tower or absorption tower arranged in vertical series, to achieve purification of the reaction gas and efficient capture of methane chloride components.

[0103] In one specific embodiment, the flash evaporation equipment can be a flash tank, a falling film flash evaporator, a vacuum flash evaporation equipment, or a reduced pressure evaporation equipment. By adjusting the operating pressure and temperature, the volatile components in the recovered washing liquid are separated from the solid residues.

[0104] In one possible embodiment, the secondary washing equipment further includes a primary washing section and a deep washing section; wherein,

[0105] The primary reaction gas inlet and the recovered washing liquid outlet are located in the primary washing section, which also includes a primary washing liquid inlet and an intermediate reaction gas outlet.

[0106] The gaseous methane chloride product outlet is located in the deep scrubbing section, which also includes a deep scrubbing liquid inlet, an intermediate reaction gas inlet, and a deep recovery scrubbing liquid outlet.

[0107] The primary washing liquid inlet and the deep recovery washing liquid outlet and the recovered washing liquid outlet are connected respectively; the intermediate reaction gas inlet and the intermediate reaction gas outlet are connected.

[0108] In this embodiment, the primary reactant gas enters the primary washing section of the secondary washing equipment through the primary reactant gas inlet, while the primary washing liquid enters the primary washing section through the primary washing liquid inlet. The primary reactant gas and primary washing liquid come into full contact within the primary washing section. Through gas-liquid mass transfer, residual solid particles, high-boiling byproducts, and some condensable components in the primary reactant gas are absorbed and carried away by the primary washing liquid, reducing the impurity load entering subsequent washing stages, resulting in intermediate reactant gas and primary recovered washing liquid. The primary recovered washing liquid is discharged through the recovered washing liquid outlet and can be returned as primary washing liquid for recycling.

[0109] The intermediate reaction gas, after primary washing, exits through the intermediate reaction gas outlet and enters the deep washing section through the intermediate reaction gas inlet. Simultaneously, the deep washing liquid enters the deep washing section through the deep washing liquid inlet, further contacting the intermediate reaction gas. This enhances gas-liquid mass transfer, improving the capture efficiency of the methane chloride component, and yielding a gaseous methane chloride product, which is then exited through the gaseous methane chloride product outlet. The deep recovery washing liquid generated during the deep washing process exits through the deep recovery washing liquid outlet and, after merging with the recovered washing liquid, can be returned to the primary washing section as a supplement to the primary washing liquid.

[0110] In one possible embodiment, it further includes a solid-liquid separation device, a concentration device, and a waste heat recovery device; the solid-liquid separation device includes a solid-liquid residual component inlet, a separated clear liquid outlet, and a separated precipitate outlet; the concentration device includes a separated precipitate inlet, a concentrated liquid phase outlet, and a concentrated solid phase outlet;

[0111] The solid-liquid residual component outlet and the solid-liquid residual component inlet are connected; the separated clear liquid outlet and the concentrated liquid phase outlet are respectively connected to the secondary washing liquid inlet; the high-temperature reaction gas outlet is connected to the high-temperature reaction gas inlet via the waste heat recovery equipment.

[0112] In this embodiment, after the high-temperature reaction gas is discharged from the high-temperature reaction gas outlet of the reaction equipment, it first enters the waste heat recovery equipment to reduce the temperature of the high-temperature reaction gas and reduce the heat load in the subsequent primary dust removal process.

[0113] The solid-liquid residues generated by the flash evaporator enter the solid-liquid residue inlet of the solid-liquid separation unit through the solid-liquid residue outlet. Inside the solid-liquid separation unit, the solid-liquid residues separate to form a clear separation liquid and a sedimentation phase. The clear separation liquid still contains a certain amount of usable liquid washing components, which are discharged through the clear separation liquid outlet and enter the secondary washing liquid inlet of the secondary washing unit, where they participate in the gas-liquid washing process as the secondary washing liquid.

[0114] The separated sediment phase obtained from the solid-liquid separation equipment enters the separated sediment phase inlet of the concentration equipment. Within the concentration equipment, residual volatile or flowable liquid phase components are further removed, resulting in a further enrichment of the effective liquid phase components, yielding a concentrated liquid phase and a concentrated solid phase. The concentrated liquid phase is discharged through the concentrated liquid phase outlet and enters the secondary washing liquid inlet of the secondary washing equipment, continuing to participate in the washing process as a washing medium. The concentrated solid phase is discharged as a solid residue that is difficult to recycle, achieving centralized treatment of solid impurities.

[0115] In one specific embodiment, waste heat recovery equipment can be implemented using heat exchangers, such as shell-and-tube heat exchangers, plate heat exchangers, or waste heat boilers. Solid-liquid separation equipment can be implemented using sedimentation separation equipment, filtration separation equipment, or centrifugal separation equipment, such as settling tanks, hydrocyclones, filters, plate and frame filter presses, and horizontal centrifuges. Concentration equipment can be implemented using evaporation concentration equipment, vacuum concentration equipment, or thin-film evaporation equipment, such as flash evaporators, falling film evaporators, scraped evaporators, or vacuum concentration devices.

[0116] In one possible embodiment, the device further includes a condensation unit and a separation unit, the condensation unit including a gaseous methane chloride product inlet, a non-condensable gas outlet, and a liquid methane chloride product outlet;

[0117] The separation equipment includes a chloromethane recovery feed outlet, a refined methane chloride product outlet, and a liquid-phase methane chloride product inlet;

[0118] The outlet of the liquid-phase methane chloride product is connected to the inlet of the secondary washing liquid and the inlet of the liquid-phase methane chloride product; the outlet of the monochloromethane recovery material is connected to the inlet of the raw material system.

[0119] In this embodiment, the gaseous methane chloride product is discharged from the gaseous methane chloride product outlet of the secondary scrubbing equipment and enters the gaseous methane chloride product inlet of the condensing equipment. Inside the condensing equipment, it transforms from a gaseous state to a liquid state, yielding a liquid methane chloride product. Simultaneously, non-condensable gas, which is difficult to condense, is separated and discharged through the non-condensable gas outlet.

[0120] The liquid methane chloride product obtained from condensation is discharged from the liquid methane chloride product outlet, and a portion of it is returned to the secondary washing liquid inlet of the secondary washing equipment to participate in the subsequent gas-liquid contact process as a washing medium, reducing the need for replenishment of external washing media.

[0121] Another portion of the liquid-phase methane chloride product enters the separation unit through the liquid-phase methane chloride product inlet. Inside the separation unit, the methane chloride product component is separated from the monochloromethane component, yielding purified methane chloride product and monochloromethane recovery feed. The purified methane chloride product is discharged through the purified methane chloride product outlet and collected as the final product; the monochloromethane recovery feed is discharged through the monochloromethane recovery feed outlet and returned to the feed system inlet of the reaction unit to participate in the substitution reaction.

[0122] Thirdly, the present invention provides a production system for methane chloride, comprising the apparatus of any of the second aspects of the present invention.

[0123] In one specific embodiment, the condensation equipment can be implemented using a gas condenser or a heat exchange condensation device, such as a shell-and-tube condenser, a plate condenser, a tube-and-tube condenser, a spray condenser, or a cryogenic condensation device. The separation equipment can be implemented using distillation equipment suitable for separating organic chloride components, such as a distillation column, a continuous distillation column, a wall-distillation column, or a multi-stage distillation separation device.

[0124] Furthermore, the device can also be equipped with a circulating pump, a transfer pump, a storage tank, a filter assembly, and a flow control assembly to achieve stable material circulation and transportation.

[0125] Thirdly, the present invention provides a production system for methane chloride, including the apparatus of any one of the second aspects of the present invention, and further including a raw material supply device and a non-condensable gas recovery device.

[0126] In this invention, the raw material supply device is used to supply reaction raw materials such as chlorine and chloromethane to the reaction equipment, and may include a raw material storage tank, a metering pump, a compressor, a flow control valve, and a mixing device. The raw material supply device is connected to the raw material system inlet of the reaction equipment, and by controlling the delivery ratio and flow rate of different raw materials, the reaction system maintains stable composition conditions.

[0127] The non-condensable gas generated in this invention mainly includes effective components such as hydrogen chloride and chloromethane. It can be sent to a non-condensable gas recovery device for resource utilization according to the overall production layout of the system, rather than being directly sent to the tail gas treatment device as waste gas.

[0128] In one specific embodiment, non-condensable hydrogen chloride can be compressed, purified, or buffered and stabilized before being transported to a hydrochloric acid production unit, where it is absorbed by water or dilute hydrochloric acid in an absorption tower to produce hydrochloric acid products; it can also be used as a chlorine source supplement for other chlorination reaction units, and added to the reaction system after being regulated by equipment such as a gas mixer and a metering control system.

[0129] In one specific embodiment, the small amount of monochloromethane contained in the non-condensable gas can be pressurized by a compressor, condensed and recovered by a condenser, or separated by a gas-liquid separator. In addition to being returned to the methane chloride production system as a reaction raw material for recycling, it can also be transported to the organosilicon monomer production unit as a raw material for the synthesis of methylchlorosilane. After being mixed with other reaction raw materials through a feed buffer tank, flow control valve and mixer, it enters the subsequent utilization unit.

[0130] In the production system, the core process units consist of the reaction equipment, primary dust removal equipment, secondary scrubbing equipment, and flash evaporation equipment. The reaction equipment is used to generate methane chloride; the primary dust removal equipment prioritizes the removal of solid particles and high-boiling, easily condensable components from the high-temperature reaction gas; the secondary scrubbing equipment further purifies the reaction gas and recovers the methane chloride product; and the flash evaporation equipment regenerates the solid-containing slurry and recovered scrubbing liquid, achieving effective liquid phase component recovery and centralized discharge of solid impurities.

[0131] Compared to traditional production systems that only involve reaction and product separation, this invention, by incorporating a staged impurity removal, washing circulation, and flash regeneration coupled structure at the reaction end, effectively controls impurities prone to deposition and clogging before they enter subsequent critical equipment, and maintains the continuous purification capability of the washing medium, fundamentally reducing the risk of impurity accumulation and equipment clogging within the system. Therefore, the apparatus provided in the second aspect of this invention is the core component for improving the anti-clogging performance and long-term continuous operation capability of methane chloride production systems.

[0132] The present invention will be described below through specific embodiments.

[0133] Example

[0134] This embodiment describes how a methane chloride production plant modified its existing production equipment using the production system and method provided by this invention. For example... Figure 1 The diagram shown is a process flow chart provided in this embodiment. Figure 2 The diagram shown is a schematic of the apparatus provided in this embodiment. High-temperature, high-pressure solid-containing gaseous material from the chlorination reactor enters the waste heat recovery equipment through the reaction gas outlet and indirectly exchanges heat with the boiler feedwater. This vaporizes the boiler feedwater to generate 0.5 MPaG saturated steam, while simultaneously reducing the temperature of the solid-containing gaseous material from the reaction temperature to approximately 180°C, thus achieving waste heat recovery and temperature regulation before subsequent dust removal treatment.

[0135] The cooled reaction gas enters the venturi dust collector, the primary dust removal equipment, through a conveying pipeline. Simultaneously, recovered washing liquid from the secondary washing equipment is injected into the throat of the venturi tube through a liquid inlet. Under the action of the high-speed airflow in the throat, the washing liquid is broken into numerous fine droplets, which mix with the solid-containing reaction gas in a high-speed turbulent flow. This causes solid particles, high-boiling-point heavy components, and easily condensable substances to be transferred to the liquid phase through inertial collisions and absorption. The temperature of the reaction gas is further reduced to approximately 150°C, where about 90% of the carbon black particles and heavy components are captured by the washing liquid, forming a solid-containing washing liquid.

[0136] The primary reaction gas, after being treated by the Venturi scrubber, enters the secondary scrubbing unit. In the primary scrubbing section of the secondary scrubbing system, the reaction gas comes into countercurrent contact with the recycled scrubbing liquid from the reboiler and the concentrated liquid phase from the solids-containing concentrate unit, further removing residual solid particles, high-boiling byproducts, and easily condensable components, reducing the impurity load entering subsequent scrubbing zones. Subsequently, the reaction gas after primary scrubbing enters the deep scrubbing section, where it comes into countercurrent contact with the liquid-phase methane chloride product from the condenser and the flash distillate from the flash evaporator, further removing fine impurities.

[0137] The purified reaction gas, after being treated by the secondary scrubbing unit, enters the condenser. Through condensation and heat exchange, the gaseous methane chloride is converted into a liquid methane chloride product, and non-condensable gas is separated. A portion of the liquid methane chloride product is returned to the secondary scrubbing unit as a deep scrubbing liquid, while the remaining liquid methane chloride product enters the separation unit for refining. The recovered scrubbing liquid from the secondary scrubbing unit is pressurized by a circulating pump and then split. One stream returns to the secondary scrubbing system to maintain the scrubbing cycle, another stream enters the venturi dust collector as scrubbing liquid, and the third stream enters the flash evaporator for regeneration.

[0138] The solid-containing washing liquid discharged from the Venturi scrubber and the solid-containing circulating liquid discharged from the secondary washing system are combined and then enter the flash evaporator. Flash evaporation is performed at an operating pressure of 0.05 MPaG, preferentially vaporizing liquid-phase methane chloride and recyclable components, separating them from solid impurities. The gaseous material generated by flash evaporation is condensed and enters the clear liquid tank to form flash condensate. The solid and liquid materials enter the settling tank for further solid-liquid separation. The separated clear liquid obtained at the top of the settling tank is filtered to further remove residual fine solid particles before entering the clear liquid tank, where it is mixed with the flash condensate and pumped by a circulating pump to the deep washing section for use as washing liquid. The solid and liquid residues formed at the bottom of the settling tank enter the concentration equipment for further processing.

[0139] In the concentration equipment, the recoverable methane chloride component is further volatilized through vacuum concentration. After being condensed by the dry gas condenser, the concentrated liquid phase is returned to the middle of the secondary washing equipment for use as washing liquid. The concentrated solid phase is treated in accordance with the requirements for hazardous waste.

[0140] Before the upgrade, the production unit required a shutdown for cleaning every three months due to the deposition of solid particles and high-boiling components in the reaction gas, with each shutdown lasting approximately five days. After the system upgrade using this invention, the unit operated continuously for 24 months without significant blockage. Inspection revealed no significant scaling in the throat of the venturi dust collector, and the trays and liquid distribution structure of the secondary scrubbing system remained unblocked. Simultaneously, the waste heat recovery system generates approximately 24,000 tons of steam annually, reducing steam consumption costs by approximately 2 million yuan per year and equipment maintenance costs by approximately 70%, significantly improving the long-term continuous operation capability of the methane chloride production unit.

[0141] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A method for producing methane chloride, characterized in that, Includes the following steps: Step 1): The raw material system, including chlorine and chloromethane, is subjected to a substitution reaction to obtain a high-temperature reaction gas; Step 2): The high-temperature reaction gas is subjected to primary dust removal treatment using primary washing liquid to obtain primary reaction gas and solid slurry; Step 3): The primary reaction gas is subjected to secondary washing treatment using secondary washing liquid to obtain gaseous methane chloride product and recovered washing liquid; the recovered washing liquid in the first part is used as the primary washing liquid in the primary dust removal treatment; Step 4): The solid-containing slurry and the recovered washing liquid from the second part are subjected to flash evaporation to obtain flash clear liquid and solid-liquid residue components; the flash clear liquid is used as the secondary washing liquid in the secondary washing process.

2. The method according to claim 1, characterized in that, The secondary washing process includes: using a primary washing liquid to perform a primary washing process on the primary reaction gas to obtain an intermediate reaction gas and a primary recovery washing liquid; The intermediate reaction gas is subjected to deep washing treatment using a deep washing solution to obtain the gaseous methane chloride product and the deep recovery washing solution. The secondary washing solution includes the primary washing solution and the deep washing solution, and the recycled washing solution further includes the primary recycled washing solution and the deep recycled washing solution; The primary washing solution also includes the remaining portion of the recycled washing solution, and the deep washing solution includes the flash-evaporated clarified liquid.

3. The method according to claim 2, characterized in that, It also includes condensing the gaseous methane chloride product to obtain a liquid methane chloride product and non-condensable gas; and returning a portion of the liquid methane chloride product as a secondary washing liquid to participate in the secondary washing process; And / or, It also includes separating the remaining portion of the liquid-phase methane chloride product to obtain refined methane chloride product and chloromethane recovery material; the chloromethane recovery material is then returned to participate in the substitution reaction process.

4. The method according to any one of claims 1-3, characterized in that, It also includes performing solid-liquid separation treatment on the solid-liquid residual components to obtain a clear separation liquid and a sedimentation phase, and using the clear separation liquid as the secondary washing liquid in the secondary washing treatment; The separated sediment phase is concentrated to obtain a concentrated liquid phase and a concentrated solid phase. The concentrated liquid phase is used as the secondary washing liquid in the secondary washing process. And / or, It also includes performing waste heat recovery treatment on the high-temperature reaction gas to obtain a low-temperature reaction gas, the temperature of which is below 250°C; and subjecting the low-temperature reaction gas to the primary dust removal treatment.

5. The method according to claim 4, characterized in that, The temperature of the primary reaction gas is below 180°C; and / or, The operating pressure during the flash evaporation process is 0.005-0.5 MPaG; the operating pressure during the concentration process is 0.05-0.1 MPaG.

6. An apparatus for producing methane chloride, used to implement the method according to any one of claims 1-5, characterized in that, This includes reaction equipment, primary dust removal equipment, secondary washing equipment, and flash evaporation equipment; The reaction equipment includes a raw material system inlet and a high-temperature reaction gas outlet; The primary dust removal equipment includes a high-temperature reaction gas inlet, a primary washing liquid inlet, a primary reaction gas outlet, and a solid slurry-containing outlet; The secondary washing equipment includes a primary reaction gas inlet, a secondary washing liquid inlet, a recovered washing liquid outlet, and a gaseous methane chloride product outlet; The flash evaporation equipment includes a solid slurry inlet, a flash evaporation recovery washing liquid inlet, a flash evaporation clear liquid outlet, and a solid-liquid residual component outlet; The high-temperature reaction gas outlet and the high-temperature reaction gas inlet are connected; The primary reactant gas outlet and the primary reactant gas inlet are connected; The recovered washing liquid outlet is connected to the primary washing liquid inlet and the flash-evaporated recovered washing liquid inlet, respectively. The solid slurry outlet and the solid slurry inlet are connected; The secondary washing liquid inlet and the flash-evaporated clear liquid outlet are connected.

7. The apparatus according to claim 6, characterized in that, The secondary washing equipment further includes a primary washing section and a deep washing section; wherein... The primary reaction gas inlet and the recovered washing liquid outlet are located in the primary washing section, which also includes a primary washing liquid inlet and an intermediate reaction gas outlet. The gaseous methane chloride product outlet is located in the deep scrubbing section, which also includes a deep scrubbing liquid inlet, an intermediate reaction gas inlet, and a deep recovery scrubbing liquid outlet. The primary washing liquid inlet and the deep recovery washing liquid outlet and the recovery washing liquid outlet are respectively connected; the intermediate reaction gas inlet and the intermediate reaction gas outlet are connected.

8. The apparatus according to claim 6 or 7, characterized in that, It also includes solid-liquid separation equipment, concentration equipment, and waste heat recovery equipment; The solid-liquid separation equipment includes a solid-liquid residual component inlet, a separated clear liquid outlet, and a separated settled phase outlet; The concentration equipment includes a separation sedimentation phase inlet, a concentrated liquid phase outlet, and a concentrated solid phase outlet; The solid-liquid residual component outlet and the solid-liquid residual component inlet are connected; The separated clear liquid outlet and the concentrated liquid phase outlet are respectively connected to the secondary washing liquid inlet; The high-temperature reaction gas outlet is connected to the high-temperature reaction gas inlet via the waste heat recovery equipment.

9. The apparatus according to any one of claims 6-8, characterized in that, It also includes condensation equipment and separation equipment, wherein the condensation equipment includes a gaseous methane chloride product inlet, a non-condensable gas outlet, and a liquid methane chloride product outlet; The separation equipment includes a chloromethane recovery feed outlet, a refined methane chloride product outlet, and a liquid-phase methane chloride product inlet. The liquid-phase methane chloride product outlet is connected to both the secondary washing liquid inlet and the liquid-phase methane chloride product inlet. The outlet of the chloromethane recovery material is connected to the inlet of the raw material system.

10. A system for producing methane chloride, characterized in that, The apparatus includes the device according to any one of claims 6-9, and further includes a raw material supply device and a non-condensable gas recovery device.

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