214 results about "Chloroethane" patented technology

The invention relates to the technical field of aluminum alloy materials, in particular to a high-temperature-resistant and high-strength aluminum alloy material and a preparation method thereof. The problems that an existing aluminum alloy material is insufficient in mechanical property and poor in high temperature resistance are solved. A plurality of strengthening elements with synergistic effects, including copper, magnesium, scandium, zirconium, nickel, manganese and titanium, are introduced into an aluminum alloy matrix, meanwhile, multiple layers of graphene nanosheets are added for step-by-step smelting, and under argon protection, hexachloroethane refining and lithium salt complexing agent grain refinement are performed to prepare a smelted alloy; and by combining the multi-stage refined smelting, the staged heat treatment process, the three-stage aging treatment and the surface modification process, the microstructure is optimized, and meanwhile the surface performance is improved. According to the prepared aluminum alloy material, through multi-element cooperation and multi-process optimization, the mechanical property, the high temperature resistance and the surface oxidation resistance of aluminum alloy are remarkably improved, and the aluminum alloy material is suitable for the field of aerospace.

The invention relates to the technical field of preparation of aluminum alloy conductor materials, and particularly discloses a preparation method of an Al-Mg-Si-RE-based aluminum alloy conductor for a 10-35kV middle and low voltage cable, which comprises the following steps: adding a microalloyed intermediate alloy into an aluminum melt by adopting an addition method, stirring, smelting, refining, and casting to form, thereby obtaining the Al-Mg-Si-RE-based aluminum alloy conductor for the 10-35kV middle and low voltage cable. And performing annealing, rolling, wire drawing and aging heat treatment to obtain a final product. Wherein in the smelting stage, raw materials are completely melted at 700-750 DEG C; hexachloroethane is used as a refining agent for refining; annealing at 330-350 DEG C and preserving heat for 4-8 hours; and aging at 300 DEG C for 10 hours after deformation. In the preparation of a wire of a 10-35kV medium and low voltage power cable, the aluminum alloy wire has high conductivity of 62.1-62.5% IACS (International Annealed Copper Standard) and tensile strength of 101-117MPa by simplifying the process steps and optimizing the element ratio on the premise of ensuring the controllable raw material cost, and the mechanical property and electrical property requirements of the medium and low voltage wire are balanced.

The present invention provides a polymer with a polar group or a heterocyclic-bridged phthalazinone structure and a preparation method thereof, which relates to the technical field of synthesis of polymer materials. The polymer with a polar group or a heterocyclic-bridged phthalazinone structure mainly has more excellent heat resistance and good solubility by introducing a polar group or a heterocyclic-bridged phthalazinone structure. Its glass transition temperature can reach up to 405 °C and it can be dissolved in polar aprotic organic solvents such as N-methylpyrrolidone and 1,1,2,2-tetrachloroethane. In addition, the present invention can also regulate the heat resistance and solubility of such polymers by adjusting the structure and proportion of the structural unit with a polar group or a heterocyclic-bridged phthalazinone structure and other structural units, so that it can meet the needs of more different application scenarios. The present invention also provides a preparation method of the above polymer.

The invention relates to a preparation method of a lithium difluoro bis (oxalate) phosphate concentrated solution, and belongs to the technical field of lithium battery electrolyte additives. Adding lithium oxalate into a solvent, stirring and dissolving to obtain a lithium oxalate solution; the method comprises the following steps: adding a modified fluorine ion chelating agent into a lithium oxalate solution, stirring, filtering, putting into a reactor, and slowly introducing phosphorus pentafluoride gas; after the introduction is finished, heating and stirring for reaction; after the reaction is finished, filtering reaction liquid to remove unreacted solid impurities, so as to obtain a lithium difluoro bis (oxalate) phosphate concentrated solution; the modified fluorine ion chelating agent is prepared from D301 ion exchange resin, dichloroethane, propylene-1-base boronic acid pinacol ester, mercaptoethyl guanidine dihydro bromide and sodium tert-butoxide. The lithium difluoro bis (oxalate) phosphate prepared by the method is high in purity and high in yield, and meets the use requirements of lithium ion battery electrolyte on lithium salt.

The invention discloses a resource utilization method of 1, 1, 2-trichloroethane waste liquid, which comprises the following steps: 1) feeding the 1, 1, 2-trichloroethane waste liquid into a scraper device to remove heavy components, and extracting gas-phase light components from the top; (2) condensing the gas-phase light component, feeding into a chlorination reactor, and carrying out chlorination reaction; and 3) carrying out reactive distillation on the material at the outlet of the chlorination reactor to remove light components and heavy components to obtain 1, 1, 2-trichloroethane. According to the method, on one hand, impurities which influence the purity of 1, 1, 2-trichloroethane and are difficult to separate react with chlorine under specific conditions to generate heavier components, and on the other hand, it is ensured that light components cannot be chlorinated into the impurities which are difficult to separate, and 1, 1, 2-trichloroethane with the purity being 99% or above can be recycled; on the other hand, 5-20 wt% of 1, 1, 2-trichloroethane is additionally generated in the reactive distillation process, waste liquid recycling is achieved, and the method has the advantages of being simple in technological process, low in energy consumption and high in product yield.

The invention discloses high-toughness weather-resistant high-temperature-resistant chlorinated polyvinyl chloride and a production method thereof, and belongs to the technical field of chlorinated polyvinyl chloride, the production method comprises pretreatment, reaction and post-treatment; the reaction comprises the following steps: sealing a reaction device, replacing air in the reaction device with nitrogen, adding pretreated polyvinyl chloride, Tween 80, styrene, 1, 2-dichloroethane and deionized water into the reaction device, stirring at 75-80 DEG C, adding azodiisobutyronitrile, fumed silica, a polyvinyl alcohol aqueous solution and methacrylic acid, then irradiating with ultraviolet light, and reacting at the temperature of 75-80 DEG C, so as to obtain the polyvinyl chloride resin. The preparation method comprises the following steps of: adding sodium hydroxide into a reaction kettle, simultaneously introducing chlorine gas, stirring, adding lime milk to adjust the pH value to 6-6.5, heating to 85-90 DEG C, adding azodiisobutyronitrile, 2-dodecyl acrylate and vinyl stearate, and stirring; the chlorinated polyvinyl chloride prepared by the invention has the advantages of high toughness, good weather resistance and high temperature resistance, and also has excellent mechanical strength, machinability and appearance.

The invention discloses a method for preparing vinyl chloride by electrocatalytic dechlorination of 1, 2-dichloroethane, a working electrode of the method takes a metal oxide as a catalyst, and the metal oxide is selected from at least one of the following metal oxides: Pd, Mn, Fe, Co, Ni, Cu, Ru and Mo. According to the invention, the metal oxide powder is used as the electrocatalyst, the catalyst is coated on the electrode material to prepare the working electrode, the working electrode is applied to electrocatalytic dechlorination reaction of 1, 2-dichloroethane, vinyl chloride can be generated at high selectivity at room temperature, a new way is opened up for production of vinyl chloride by electrocatalytic dechlorination, and the method has wide application prospect. And a green and low-cost solution is provided for efficient synthesis of vinyl chloride.

The present application relates to the field of non-woven fabric technology, and specifically discloses a biodegradable non-woven fabric and its preparation method. The non-woven fabric is mainly made of the following raw materials in parts by weight: 100 parts of polypropylene, 1-2 parts of biodegradable masterbatch, 6-8 parts of modified chitosan, 3-5 parts of maleic anhydride grafted polypropylene, and 1-2 parts of antioxidant; the modified chitosan is obtained by treating chitosan with sodium hydroxide, 1-chlorododecane, and 4-(2-chloroethane acylamino) ethyl benzoate. The biodegradable non-woven fabric has the advantages of high breaking strength and good degradability, expands the scope of application, can solve the environmental pollution problem caused by the difficulty of degradation of traditional polypropylene non-woven fabrics, and meets market demand.

The invention provides a method for detecting chloroethane in hexyl aminolevulinate hydrochloride and application, the method comprises the following steps: preparing a reference solution and a test solution, the reference solution is a standard chloroethane solution, and the test solution is a hexyl aminolevulinate hydrochloride solution containing chloroethane; respectively injecting the reference solution and the test solution into a GC-MS (Gas Chromatography-Mass Spectrometer) by adopting a headspace sampling mode, and recording chromatograms; calculating the content of chloroethane in the test sample according to a peak area by an external standard method; the used gas chromatographic column is DB-FFAP, and the adopted gas chromatographic determination conditions are as follows: the flow of the chromatographic column is 1-10ml / min; the initial temperature of the column temperature is 25-50 DEG C, the initial temperature is maintained for 1-10 minutes, and the initial temperature is increased to 150-250 DEG C at the rate of 10-50 DEG C / min and maintained for 1-10 minutes; the temperature of a sample inlet is 150-30 DEG C; the sample size is 0.5 to 5 ml; the mass spectrum conditions are as follows: the operation time is 5-20 minutes; and the mass-to-charge ratio of chloroethane is 64 and 66. The method can be used for accurately and quickly detecting the content of chloroethane in hexyl aminolevulinate hydrochloride.

The utility model relates to a low-acidity high-purity difluorochloroethane alkali washing system, which is characterized in that two stages of alkali washing towers are respectively matched with an alkali washing tank, a first alkali washing tower is connected with a first alkali washing tank, the first alkali washing tank is divided into three paths after passing through a first alkali washing pump and a first cooler, and the three paths are respectively connected with the first alkali washing tank, a sodium hypochlorite storage tank and a first condenser and then are connected with the upper part of the first alkali washing tower; a cooling liquid inlet pipe of the first cooler is connected with a flow regulating valve, the bottom of a second alkaline washing tower connected with the top of the first alkaline washing tower, the structures of the second alkaline washing tower and the second alkaline washing tank are the same as those of the first alkaline washing tower and the first alkaline washing tank, and the top of the second alkaline washing tower is connected with an alkaline washing separator buffer. The controller is used for collecting the temperature of alkali liquor sent out of the alkali washing tank and the cooler and entering the alkali washing tower, so that the opening degree of the flow regulating valve is controlled to enable the alkali liquor to be sent into the alkali washing tower within a certain range, and alkali washing efficiency is improved.

The invention discloses a method for synthesizing 2-aminopyridine, comprising using polystyrene resin beads as a carrier, a mixed solvent consisting of 1,2-dichloroethane and anhydrous ethanol as a porogen, adding the polystyrene resin beads and the mixed solvent to a flask for swelling; adding N,N-dimethylaniline to the flask, and performing a stirring reflux reaction; repeatedly washing the mixed solution in the flask with anhydrous ethanol and filtering it with suction, and finally vacuum drying it at room temperature. The method for synthesizing 2-aminopyridine utilizes polymer resin beads as a carrier, grafts a preferred highly active phase transfer catalyst molecule - N,N-dimethylaniline, and synthesizes a solid-supported phase transfer catalyst to achieve efficient recycling and regeneration of the phase transfer catalyst, and ensures the yield of the pyridine amination product by the solid-supported phase transfer catalyst, which is conducive to ensuring the efficient resource utilization of basic nitrogen heterocyclic compounds in coal tar.

The application discloses a high-beta-crystal-phase polyvinylidene fluoride fiber piezoelectric film and a preparation method thereof, wherein the preparation method comprises the following steps: step one: polyvinylidene fluoride resin with a weight average molecular weight of 500,000-800,000, a long branched chain content of 1.2‰-5‰, and a 7% mass fraction NMP solution rotary viscosity of 5000-8000 mpa.s at 25 DEG C is prepared by emulsion polymerization of polyvinylidene fluoride monomer and difluoro-monochloroethane; and step two: the polyvinylidene fluoride resin obtained in step one is made into an electrostatic spinning precursor solution, and the electrostatic spinning precursor solution is spun and film-formed by an electrostatic spinning method. The polyvinylidene fluoride nanofiber film with finer and higher beta-crystal-phase content can be prepared by adjusting the content of the long branched chain and the viscosity of the electrostatic spinning solution.

A process is disclosed for producing ethylene dichloride from monoethylene glycol and hydrogen chloride in the presence of water, thereby forming an ethylene dichloride-rich liquid phase that can be readily separated from a coexisting aqueous phase. The reaction is carried out under conditions that limit both 2-chloroethanol and ethylene dichloride in the vapor phase, facilitating high conversion efficiencies and minimizing ethylene dichloride losses. The process includes a reaction step in which monoethylene glycol is converted to 2-chloroethanol and subsequently to ethylene dichloride, generating water that aids in separating by-products from the ethylene dichloride-rich phase. A phase-separation system is employed to decant the heavier, ethylene dichloride phase from an aqueous phase containing residual reactants and by-products. Additional purification steps, such as washing with substantially anhydrous monoethylene glycol, further remove water, acids, and 2-chloroethanol, producing high-purity ethylene dichloride. Recycling unconverted monoethylene glycol and 2-chloroethanol to the reactor increases overall conversion and enhances process economics.

The utility model relates to the technical field of hexachloroethane raw material storage, in particular to a hexachloroethane raw material storage device with a protective structure, which comprises a storage tank, a cover, a first protective shell, a protective cover and a mounting plate. Two sets of mounting plates are fixedly connected into the first protective shell, one set of mounting plates comprises four mounting plates, and a storage tank is arranged between the two sets of mounting plates. A double-layer protection structure is formed by the storage tank and the first protection shell, materials are prevented from making direct contact with the external environment when the inner shell leaks, when the inner shell is damaged, the outer layer can still prevent hexachloroethane from leaking out, and the double-layer protection structure can better protect hexachloroethane in the storage tank.

The invention provides a method for preparing ethyl alkyl ethyl phosphinate through catalysis, which comprises the following steps of: after replacing air in a reaction kettle with inert gas, adding dialkyl alkyl phosphinate, halothane and a supported ruthenium chloride catalyst; and stirring and reacting at a certain temperature for a certain time to prepare alkyl ethyl phosphinic acid ethyl ester, and filtering to obtain the product. Compared with catalysts iodoethane and chloroethane, the chloroethane has the characteristics of low cost, easiness in obtaining and low toxicity, the reaction out-of-control risk is low due to low catalytic activity, and the reaction temperature can be reduced by combining the catalyst with the supported ruthenium chloride.

The application discloses a preparation method of acetic acid 2,2-difluoroethyl ester and belongs to the technical field of battery electrolyte additives. The application takes alkali metal acetate and 2,2-difluoro-1-chloroethane as reaction raw materials, prepares acetic acid 2,2-difluoroethyl ester in dimethyl sulfoxide, and then adopts a post-treatment process of extracting the reaction liquid first and then distilling, so that the problem that the interaction between dimethyl sulfoxide and the product is difficult to distill is effectively avoided, and problems, such as the decomposition of dimethyl sulfoxide at high temperature to reduce the purity of the product and the combination of the decomposition product and the product, are also avoided. Meanwhile, the reaction condition of the application is mild, the operation is simple, a complex catalytic system is not needed, and the application does not depend on specific reaction equipment, so the application has a good large-scale industrial production prospect.

The filter device comprises a fixed barrel, a delivery pump and a filter cartridge, the input end of the delivery pump is fixedly installed at one end of a connecting pipe, the other end of the connecting pipe is fixedly installed in one side of the fixed barrel, and the output end of the delivery pump is fixedly installed at one end of a delivery pipe. And the other end of the conveying pipe is fixedly mounted in one side of the purifying tower. By arranging the filter cartridge, impurities in a liquid mixture can be effectively filtered before the liquid mixture enters the purifying tower, the rectification effect is prevented from being influenced, and the filter cartridge is provided with the notch, the rubber gasket, the fixed block, the limiting clamping groove, the connecting block, the sliding groove, the spring, the sliding block, the limiting clamping block, the shifting block, the handle and the like; the sealing cover can be installed and fixed through the connection of the sealing cover, the rubber gasket and the notch and the connection of the limiting clamping block and the limiting clamping groove, the sealing cover is convenient to disassemble and assemble through the arrangement of a handle, a shifting block and the like, and the operation is more labor-saving compared with the operation of screwing the sealing cover.

The invention relates to the field of toluene recovery, and discloses a device and a method for recovering and washing toluene. The device comprises a filter and a rectifying tower, the filter comprises a filter screen cylinder and two carbon steel steel pipes which are positioned in the center of the filter screen cylinder and are provided with magnets at the tail ends; the rectifying tower comprises a feeding port and side line discharging ports located in the different sides of the feeding port. The feeding port is located above the side line discharging port. By arranging the filter, the device can be prevented from being blocked by solid particles and rust in materials, the online densimeters are arranged at the feed port of the rectifying tower above the side line discharge port and at different sides and on the side wall of the reflux tank at the top of the tower, volatile substances are intermittently extracted from the top of the rectifying tower, and methylbenzene is continuously extracted from the side line of the rectifying tower; according to the process, impurities such as hexane and chloroethane can be effectively removed, the content of toluene in tower top distillate is reduced, and waste caused by discharge is reduced.

The invention discloses a preparation method of tris (2-cyanoethyl) phosphate, which comprises the following steps of: 1, adding 3-hydroxypropionitrile, an organic alkali acid-binding agent and a reaction organic solvent which is one of dichloromethane and dichloroethane into a reaction container, and reacting at the temperature of between 20 and 30 DEG C for 1 to 3 hours; controlling the temperature not to exceed 20 DEG C, dropwise adding a mixture formed by phosphorus trichloride and a reaction organic solvent, after dropwise adding is completed, performing heating reflux reaction, and after the reaction is completed, performing suction filtration to remove generated organic alkali hydrochloride so as to obtain filtrate; and 2, controlling the temperature of the filtrate obtained in the step 1 at 30-40 DEG C, introducing oxygen for reaction until the reaction is finished, and removing the reaction organic solvent to obtain the final product tris (2-cyanoethyl) phosphate. The method has the advantages of simplicity in operation, mild and controllable reaction, high product purity and suitability for industrial popularization.

The invention relates to the technical field of medical analysis, and particularly provides a method for determining the content of 1, 2-dichloroethane in a residual solvent of 4-cyano-2-methoxybenzaldehyde. The method comprises the following steps: 1) preparing a reference solution and a test solution; 2) setting headspace sampling conditions; 3) setting gas chromatographic analysis conditions, and separating 1, 2-dichloroethane from other impurities by using a capillary chromatographic column of 6% cyanopropyl phenyl-94% dimethyl polysiloxane and a carrier gas of nitrogen by using a heating program; and 3) respectively sucking the reference substance solution and the test solution, injecting into a gas chromatograph, and recording a chromatogram. The method disclosed by the invention can be used for rapidly, effectively, accurately and reliably detecting the content of the residual solvent 1, 2-dichloroethane of the 4-cyano-2-methoxybenzaldehyde so as to meet the requirements of drug quality control.

The utility model relates to the technical field of chloroethane recovery, and discloses a chloroethane recovery condenser which comprises a condensation tank, an air inlet pipe, a flange, a first control valve, a sealing piece, a valve handle, a liquid outlet pipe, a runner plate, a heat transfer plate, a pressure sensor, a temperature sensor, a water pump, a control panel, a refrigerating machine and an exhaust valve. The design of the flange and the first control valve provides good system sealing performance and flow control capability, the liquid storage tank on the left side of the condensation tank and the equipment box body provide necessary auxiliary functions such as storage and refrigeration for the condensation process, the arrangement of the exhaust valve provides a safe exhaust way for the system, and the safety of the operation environment is guaranteed. According to the chloroethane recovery condenser, through the design that the heat transfer plate and the runner plate are arranged, the condenser can greatly improve the heat exchange efficiency between chloroethane and a cooling medium, the condensation process is accelerated, and therefore the recovery efficiency of the chloroethane is improved.

The invention relates to a device and a method for producing partially chlorinated alkanes by means of a direct chlorination of alkenes. In particular, the invention relates to a device and a method for producing 1,2-dichloroethane by means of a direct chlorination of ethene (synonym: ethylene). The invention is characterized in that a loop reactor is used for the direct chlorination, wherein the outlet for the produced partially chlorinated alkane is provided on a vertical position of the loop reactor (in the operating state) on a lateral wall of the loop reactor, the vertical position being situated below half the height of the loop reactor.

The application provides a synthesis method of 9,10-dibromoanthracene, by introducing HBr generated by a solvent water adsorption reaction, using an industrial sodium hypochlorite solution to react the HBr into bromine, ensuring high concentration of bromine, introducing a solvent dichloroethane to uniformly disperse raw materials, keeping the concentration of bromine stable in the reaction, greatly promoting the reaction speed, greatly shortening the reaction time, and converting the sodium hypochlorite into a sodium chloride aqueous solution after the reaction is completed. The purity of the prepared 9,10-dibromoanthracene is more than 99%, and the by-products generated in the reaction are environment-friendly and non-polluting.

The application discloses a preparation method and application of a catalyst for cracking 1,2-dichloroethane to produce vinyl chloride, and comprises the following steps: 1) a neodymium ore is leached with hydrochloric acid, and after filtering a leaching solution, potassium chloride is added to form a doped precursor K2[NdCl3]; 2) an active metal oxide is dissolved in hydrochloric acid, and then added into the doped precursor K2[NdCl3] solution, and co-precipitation is carried out by adding alkali to obtain an emulsion of a doped active component; the active metal oxide is at least one of oxides of vanadium, manganese, titanium and scandium; 3) the emulsion of the doped active component is mixed with a liquid carrier to obtain the catalyst; the liquid carrier is one or more of chloroform, carbon tetrachloride, 1,1,2-trichloroethane and chlorobenzene.

The invention discloses a dapagliflozin intermediate synthesis method and application, and the dapagliflozin intermediate synthesis method comprises the following steps: heating 2-chloro-5-bromobenzoic acid, 1, 2-dichloroethane, bis (trichloromethyl) carbonate and a catalyst for reflux reaction, and cooling to obtain a 2-chloro-5-bromobenzoyl chloride solution; the preparation method comprises the following steps: mixing phenetole, 1, 2-dichloroethane and aluminum trichloride, stirring, and dropwise adding a 2-chloro-5-bromobenzoyl chloride solution to obtain 2-chloro-5-bromo-4 '-ethoxybenzophenone; and synthesizing the 4-bromine-2-chloro-2-(4-ethoxybenzyl) benzene. According to the method, the cheap BTC is used as an acylating chlorination reagent, so that the reagent cost is greatly reduced, the dosage of NaBH4 and AlCl3 in carbonyl reduction is reduced, the reagent cost and the amount of three wastes in the industry are further reduced, a foundation is laid for industrial production of the dapagliflozin intermediate, the yield is relatively high after each step of reaction, and the production cost of an enterprise is reduced.

A kettle cover is arranged at the top end of a kettle body, a plurality of second connecting plates are arranged on the periphery of the kettle cover, the second connecting plates correspond to first connecting plates of the kettle body in a one-to-one mode and are connected with the first connecting plates of the kettle body in a fastening mode, and an inwards-concave surrounding plate is arranged at the bottom of the kettle cover and connected with the inner wall of the kettle body. An annular groove is formed in the outer edge of the inwards-concave surrounding plate, a sealing ring is arranged in the annular groove formed in the inwards-concave surrounding plate, the sealing ring is pressed on the inner wall of the kettle body and the inner wall of the kettle cover, a plurality of first reinforcing plates are evenly arranged on the sealing ring in the radial direction, the bottoms of the first reinforcing plates are connected with the inner wall of the inwards-concave surrounding plate, and a stirring paddle is arranged in the kettle body. Meanwhile, a plurality of first reinforcing plates are arranged in the kettle cover, and the bottoms of the first reinforcing plates are supported on the concave coaming, so that the supporting performance of the kettle cover and the concave coaming is greatly improved, leakage caused by deformation of the kettle cover or the concave coaming in the long-term use process is avoided, and the service life is prolonged.

The invention relates to a method for preparing 5-fluoro-2-bromobenzotrifluoride through bromination, and relates to the technical field of organic synthesis.The method comprises the following steps that fluorobenzotrifluoride, an acid medium and a catalyst are added into a solvent, bromine is added at the temperature of-10 DEG C to 60 DEG C, the dropwise adding time is 1-6 h, heat preservation is conducted, a bromination reaction is conducted for 2-24 h, and reaction liquid is obtained; the acid medium comprises chlorosulfonic acid; the solvent comprises any one or two of dichloromethane, dichloroethane, trichloromethane and tetrachloromethane; the catalyst comprises any one or two of sulfur, sodium sulfide and potassium sulfide; filtering the reaction liquid, and standing and separating the filtrate to obtain an organic phase; the filter cake is a catalyst and can be repeatedly used; distilling and concentrating the organic phase to obtain a concentrated solution; and carrying out rectification separation on the concentrated solution to obtain the 5-fluoro-2-bromobenzotrifluoride. The method has the advantages of few reaction steps, simplicity in operation and environmental friendliness, and the product has high yield and high purity.

The utility model discloses a dichloroethane dehydration system and belongs to the technical field of rectification and purification. According to the technical scheme, the dichloroethane dehydration system comprises a refined dichloroethane cooler, a dehydration tower feeding / discharging heat exchanger, a dehydration tower, a dehydration tower top condenser, a mixer, a dehydration tower top reflux tank and a controller, an inlet of the dehydrating tower feeding / discharging heat exchanger is connected with a wet dichloroethane feeding pipeline, the wet dichloroethane feeding pipeline is provided with a first flow transmitter and a first flow adjusting valve, an outlet of the dehydrating tower feeding / discharging heat exchanger is connected with the dehydrating tower through a pipeline, and the bottom of the dehydrating tower is connected with a dehydrating tower bottom reboiler. The bottom of the dehydrating tower is also connected with a refined dichloroethane discharging pipeline; and the refined dichloroethane discharging pipeline is provided with a dehydrating tower bottom discharging pump, a refined dichloroethane cooler, a discharging regulating valve, a flow transmitter II and a water analyzer. The device has the advantages of high separation effect, continuous, stable and reliable operation and obvious economic effect.

The application discloses a synthesis method of 2,2-difluoroethylamine, which comprises the following steps: mixing a solvent, a copper-based catalyst and an ammonia source in a sealed container, wherein the ammonia source is gaseous, liquid or supercritical ammonia; heating the mixed system to 80-120 DEG C; adding 2,2-difluoro-1-chloroethane; keeping the reaction for a certain time; filtering the reaction liquid; and distilling the filtrate to obtain 2,2-difluoroethylamine. The reaction selectivity and reaction yield of the method are obviously improved compared with the prior art. The insoluble copper salt and organic ligand are adopted in the form of the catalyst, so that the catalyst recovery is simple and convenient, the ammonia excess ratio can be reduced in the reaction process, the energy consumption for ammonia recovery is greatly saved, the reaction yield is high, the amount of three wastes is small, and large-scale industrial production can be easily realized.

The application relates to a method for preparing graphene by solid-liquid in-situ reaction and graphene prepared by the method. The method comprises the following steps: heating and melting magnesium or a magnesium alloy in a crucible to obtain a melt; adding solid hexachloroethane into the melt at a speed of 1 g / min to 20 g / min and performing mechanical stirring, and then standing to obtain a mixture containing graphene above the melt; the mass amount of the solid hexachloroethane is 2% to 5% of the mass of the melt; separating the obtained mixture containing graphene from the melt; and performing post-treatment on the mixture containing graphene separated from the melt to obtain graphene. The application provides a method for preparing graphene in large quantities at low cost, with high production efficiency and high quality; the method has the advantages of simple operation, simple production equipment, low production cost, high yield, high graphene quality, fewer defects and impurities, excellent product performance and the like.