478results about "Halogenated hydrocarbon separation/purification" patented technology

The invention provides an HCFC-22 production method with net zero emission of by-product HFC-23, a production process system integrates a conversion and utilization process system of the by-product HFC-23 in the HCFC-22 production process, the HCFC-22 production process is coupled with a conversion process of HFC-23 and CHCl3, the by-product HFC-23 generated in the HCFC-22 production process is directly converted into HCFC-22 and HCFC-21 in the system, and the HCFC-22 and CHCl3 are converted into HCFC-22 and CHCl3. Through further separation and purification and raw material index control, the HFC-23 conversion catalyst keeps good activity, selectivity and stability, HFC-23 generated in the HCFC-22 production process can be effectively converted, and zero emission of HFC-23 in a system is achieved. The method is simple in process, low in investment cost, low-carbon, environment-friendly, efficient in emission reduction and capable of realizing net zero emission of the byproduct HFC-23 of the HCFC-22 production system.

The method for producing a halogenated alkene converts a halogenated alkane having 2 to 4 carbon atoms and containing a fluorine atom into a halogenated alkene having 2 to 4 carbon atoms and containing a fluorine atom in the gas phase in the presence of silicon oxide and an alkali metal element.

A process for producing propylene and hydrogen from propane, the process comprising the steps of: a) reacting a mixture comprising propane and bromine to produce a first reaction mixture comprising bromopropane and hydrogen bromide, b) subjecting the first reaction mixture obtained in step a) to at least one separation step to obtain a bromopropane-rich composition and to obtain a hydrogen bromide-rich composition, c) subjecting the bromopropane-rich composition obtained in step b) to a catalytic reaction to produce a second reaction mixture containing propylene and hydrogen bromide, d) subjecting the second reaction mixture obtained in step c) to at least one separation step to obtain a hydrogen bromide-rich composition and to obtain propylene, and e) subjecting the hydrogen bromide-rich composition obtained in step b) and / or the hydrogen bromide-rich composition obtained in step d) to electrolysis to obtain hydrogen and a bromine-containing composition, wherein preferably at least a portion of the bromine-containing composition is recycled back to step a).

The invention relates to a dichloromethane separation technology, in particular to a dichloromethane separation system capable of replacing centrifugal washing based on a PC project, which comprises a dichloromethane separator, a high-efficiency coalescer and a pre-filtering assembly, the pre-filtering assembly comprises a main filtering tank, an auxiliary filtering tank, a main separation channel arranged on the main filtering tank, an auxiliary separation channel arranged on the auxiliary filtering tank and filters arranged in the main filtering tank and the auxiliary filtering tank; a channel conversion assembly and a driving assembly are installed on the pre-filtering assembly, the input end of the channel conversion assembly is connected with the output end of the driving assembly, and the channel conversion assembly is used for controlling opening or closing of the main separation channel and the auxiliary separation channel; the channel switching assembly and the driving assembly are matched to synchronously open and close the main separation channel and the auxiliary separation channel on the pre-filtering assembly, a pure mechanical transmission structure is adopted, switching use is more convenient, operation is more stable, and damage is not likely to happen.

The invention discloses a resourceful treatment method for mother liquor in a glycine production process. The method comprises the following steps: introducing hydrogen chloride gas into mother liquor in a glycine production process to obtain hydrolysate; centrifugally separating the hydrolysate to obtain an ammonium chloride product, and treating the primary centrifugal filtrate in the next process; adding urea into the centrifugal filtrate for reaction, and after the reaction is completed, carrying out centrifugal separation to obtain a solid product urea-formaldehyde resin and a secondary centrifugal filtrate; the secondary centrifugal filtrate is heated, methyl alcohol in the filtrate is removed, methyl chloride is recycled, then heating continues, water in the filtrate is removed, evaporation condensate water is obtained, methyl chloride can be collected to serve as a by-product to be sold, the evaporation condensate water is reused for glycine production, and evaporation residual liquid serves as organic matter fertilizer to be treated. Under the condition of low energy consumption, impurities such as urotropin, ammonium chloride and methanol ammonia in the glycine mother liquor are separated, and resources such as urotropin, ammonium chloride and methanol in the mother liquor are recycled.

The invention discloses a high-purity fluorobenzene recovery process in 1, 4-bis (4-fluorobenzoyl) benzene production, and belongs to the technical field of organic waste liquid recovery, the process comprises the following steps: 1, enabling fluorobenzene waste liquid to pass through a tubular reactor filled with anhydrous aluminum chloride particles to react to obtain dewatered fluorobenzene waste liquid, the reaction temperature is 5-40 DEG C, the retention time is 60-200min, and the flow velocity of the fluorobenzene waste liquid is 0.1-0.4 m / min; 2, the water-removed fluorobenzene waste liquid is filtered through a micron filter and then enters a fluorobenzene rectifying tower to be rectified, organic steam on the tower top is compressed through a compressor, subjected to heat exchange through an MVR heat exchanger and condensed and then enters a reflux tank to be refluxed, high-purity fluorobenzene is extracted from the fluorobenzene rectifying tower, the purity of the fluorobenzene is larger than 99.99 wt%, and the mass content of water is smaller than 10 ppm. The fluorobenzene waste liquid in the production process of 1, 4-bis (4-fluorobenzoyl) benzene is used as a raw material, continuous batch production of high-purity fluorobenzene is achieved through reaction dehydration, crystalline aluminum chloride filtration and rectification, the process is simple, and energy consumption is low.

The invention relates to a method for separating octafluoropropane and hexafluoropropane, which comprises the following steps: carrying out adsorption separation on a mixed gas containing hexafluoropropane and octafluoropropane by using an adsorbent containing a metal organic framework material, the metal organic framework material comprises metal ions and an organic ligand, and the organic ligand comprises a compound as shown in formula I; the metal ions are selected from one or more of transition metal ions and alkaline earth metal ions. The metal organic framework material has good material stability, the synthesis conditions are mild and simple, and the raw materials are low in price. The metal organic framework material provided by the invention has very high adsorption separation selectivity on hexafluoropropylene and octafluoropropane, and has a good industrial application prospect. # imgabs0 #

The present invention provides a vinyl chloride monomer efficient water removal device and a method for efficient water removal thereof. In the vinyl chloride monomer efficient water removal device, a coalescing filter element made of polyphenylene sulfide or fluoropolymer is installed in a coalescer, which not only has a stable and reliable water removal effect, but also is effective even when there is a surfactant in the vinyl chloride monomer and the interfacial tension is lower than 3 dyne / cm. The device also has a large coalescing treatment capacity, a small number of coalescing filter elements, a small size of the coalescer, and small equipment investment and operating costs. Furthermore, the vinyl chloride monomer efficient water removal device of the present invention adopts an integrated skid-mounted design, has a high degree of integration, saves space, and is easy to transport and install.

The invention provides a method for preparing p-chloromethyl styrene, which comprises the following steps: (1) in the presence of a catalyst and an assistant, carrying out reaction on paraformaldehyde and hydrogen chloride to obtain a chloromethylation reagent; (2) reacting beta-halogenated ethyl benzene with the chloromethylation reagent obtained in the step (1) to obtain chloromethyl halogenated ethyl benzene; (3) adding an extracting agent into the chloromethyl halogenated ethylbenzene reaction liquid obtained in the step (2) for extraction to obtain an oil layer containing chloromethyl halogenated ethylbenzene and a water-containing acid layer, and crystallizing the oil layer to obtain purified p-chloromethyl halogenated ethylbenzene; and (4) in the presence of a solvent, carrying out elimination reaction on the purified p-chloromethyl halogenated ethyl benzene and alkali to obtain p-chloromethyl styrene.

Disclosed in the present invention is a method for producing 2,3,3,3-tetrafluoropropene from 1,1,2,3,3,3-hexafluoropropene, comprising: (a) introducing 1,1,2,3,3,3-hexafluoropropene and hydrogen into a first reactor for a catalytic reaction to obtain a first reaction product; (b) separating the first reaction product to obtain 1,1,1,2,3,3-hexafluoropropane; (c) introducing 1,1,1,2,3,3-hexafluoropropane into a second reactor for a catalytic reaction to obtain a second reaction product; (d) separating the second reaction product to obtain 1,2,3,3,3-pentafluoropropene; (e) introducing 1,2,3,3,3-pentafluoropropene and hydrogen into a third reactor for a catalytic reaction to obtain a third reaction product; (f) separating the third reaction product to obtain 1,1,1,2,3-pentafluoropropane; (g) introducing 1,1,1,2,3-pentafluoropropane into a fourth reactor for a catalytic reaction to obtain a fourth reaction product; and (h) separating the fourth reaction product to obtain a final product of 2,3,3,3-tetrafluoropropene. The present invention has the advantages of being simple in process, low in cost, high in efficiency, green, and environmentally friendly.

The invention belongs to the field of medicines, and discloses a continuous rectification process and equipment for brominated alkane. The continuous rectification equipment for brominated alkane comprises an extraction device and a rectification device, and the extraction device comprises a hydrobromic acid extraction tower, a water washing extraction tower and an alkali washing extraction tower; the rectification device is double-tower rectification equipment and comprises a light component removal tower and a refining tower; or the rectification device is single-tower separation equipment and comprises a refining tower. The invention also discloses a continuous rectification process for brominated alkane, which comprises the following steps of: performing three-stage extraction and refining to obtain a brominated alkane product. (1) compared with the traditional process, the brominated alkane rectification process adopts a combined process of three-stage extraction and two-stage refining to recover alcohol substances, the treatment capacity is large, the purity of a brominated alkane product can reach the medicine field, and the product yield is higher; according to the method, water in brominated alkane is effectively removed by adopting extraction standing oil-water separation and azeotropic light component removal, drying is not needed, and no solid waste is generated in the system.

The invention belongs to the technical field of brominated flame retardant synthesis, and particularly provides a decabromodiphenyl ethane bromine distillation process chlorination bromine removal process, which comprises the following steps: S1, adding bromine into a reaction kettle, adding a catalyst, and mixing; cooling and dropwise adding molten diphenylethane; then heating, carrying out a heat preservation reaction, and cooling to obtain a brominated crude product; s2, S201, adding the brominated crude product obtained in S1 into a bromine steaming kettle, and heating; s202, chlorine is introduced, and the total amount of bromine and chlorine is detected; carrying out segmented control on the introduced chlorine according to the total amount of bromine and chlorine; s203, when the total amount of bromine and chlorine is reduced to a threshold value, stopping introducing chlorine, standing, cooling, and introducing nitrogen; s3, filtering the feed liquid in the bromine steaming kettle, washing and purifying for three times, and finally, centrifugally dewatering to obtain a faint yellow solid; and S4, adding the faint yellow solid into a high-temperature jet mill, performing high-temperature aging to obtain white powder, and then performing jet milling on the white powder to obtain a finished product. Physical distillation is replaced by chemical replacement, so that bromine is highly separated.

The invention relates to a method for purifying a photoacid generator for photoresist, which comprises the following steps: adding an alcohol solvent into the photoacid generator, stirring and dissolving, then adding bismuth salt, and continuously stirring; filtering, concentrating filtrate, adding an organic solvent for dissolving, and then adding an adsorbent for adsorbing; the method comprises the following steps: filtering, concentrating a filtrate, dissolving with an alcohol solvent, adding into an aqueous solution containing a chelating agent, reacting, separating out a solid, filtering, washing a filter cake, and drying to obtain the purified photoacid generator, so that the removal of tungsten ions in the photoacid generator is realized, the concentration of tungsten in the purified photoacid generator is less than 5ppb through detection, and the yield of tungsten ions in the photoacid generator is more than or equal to 90%. And the product can be qualified and applied to the next section.

To provide a composition for heat transfer fluid as a novel mixture.SOLUTION: The present invention provides a composition for heat transfer fluid containing a hexafluoropropene trimer represented by C9F18, (i) CmF2m and / or CnF(2n-2) (in the formula, m is an integer from 4 to 12 other than 9. n is an integer from 4 to 12), (ii) water (the content of water is 0.0001-0.1 pt.mass relative to 100 pts.mass of the total amount of the hexafluoropropene trimer represented by C9F18), and / or (iii) fluoride ions (the content of the fluoride ions is 0.0000001 to 5 pts.mass relative to 100 pts.mass of the total amount of the hexafluoropropene trimer represented by C9F18).SELECTED DRAWING: None

The invention belongs to the field of chemical production, and particularly relates to a chloromethane cooling recovery system and a chloromethane cooling recovery method. The chloromethane cooling recovery system provided by the invention comprises a first condenser, a second condenser, a third condenser and a recovered chloromethane storage tank, a shell pass inlet of the second condenser is connected with a tube pass outlet of the third condenser, and a tube pass inlet of the third condenser is used for introducing liquid chloromethane. Chloromethane is cooled and recovered by using a liquid chloromethane vaporization heat absorption principle, so that the economical efficiency is good; in addition, due to the fact that the to-be-cooled object and the refrigerant are both methyl chloride, even if mutual leakage occurs in the heat exchange process, the quality of recycled methyl chloride cannot be affected, and raw material losses cannot be caused.

Belonging to the technical field of fine chemical product separation and purification, the invention discloses a beta-bromophenylethane rectification purification process, which comprises the steps of system negative pressure pretreatment, falling film evaporation directional separation, structured packing layer gas-liquid mass transfer, precise reflux ratio regulation and control, segmented collection (front fraction-qualified product), and residual liquid treatment and system circulation. According to the process, the negative pressure of a system is stabilized at 800-1200 Pa, the material temperature of a falling film evaporation discharging end is controlled at 125-135 DEG C, the feeding flow is stabilized at 1.8-2.2 m / h, the reflux ratio is regulated and controlled at 0.8: 1-1.2: 1, and the process realizes efficient purification of beta-bromopheny ethane through precise negative pressure control, synergistic linkage of falling film evaporation and a rectifying tower, segmented material collection and a circular treatment mechanism, so that the process is suitable for industrial production of beta-bromopheny ethane. According to the method, the purity of beta-bromopheny ethane can stably reach 99.5% or above, the material recovery rate is increased to 92% or above, energy consumption is reduced by 15-20% compared with that of a traditional process, material thermal decomposition loss is avoided, and the method is suitable for industrial large-scale production.

The invention discloses a green synthesis method of a high-purity hexafluoropropylene tripolymer, and relates to the technical field of hexafluoropropylene tripolymer preparation. The preparation method comprises the following specific steps: adding a hexafluoropropylene monomer into a reaction kettle, cooling the reaction kettle to a reaction temperature, slowly adding a high-activity catalyst, simultaneously starting stirring, and maintaining the reaction temperature and pressure; after the reaction time is up, cooling the reaction system, terminating the reaction, filtering and recovering the high-activity catalyst, and carrying out vacuum distillation to separate unreacted hexafluoropropylene monomers and byproducts, so as to obtain a hexafluoropropylene tripolymer crude product; and further purifying the hexafluoropropylene tripolymer crude product through column chromatography to obtain the high-purity hexafluoropropylene tripolymer. Due to the special structure and functional groups of the catalyst, the selectivity of a reaction product and the conversion rate of raw materials can be improved, and the high-purity hexafluoropropylene tripolymer can be prepared.

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 a preparation process of 2-bromoheptafluoropropane, which takes heptafluoropropane as a raw material to carry out bromination reaction, specifically, hydrogen on a No.2 carbon atom is substituted by bromine to generate 2-bromoheptafluoropropane, and hydrogen bromide is generated at the same time. And hydrogen bromide is absorbed by water and then is treated by liquid caustic soda to generate sodium bromide.

The invention provides a process for co-production of HFC-236ea, Z-HFO-1225ye, E-HFO-1225ye and HFO-1234yf, and the process comprises the following steps: reacting hydrogen with HFO-1225ye in the presence of a first catalyst to obtain a first reaction product flow; mixing the first reaction product flow with HFP, and reacting in the presence of a second catalyst to obtain a flow containing HFC-245eb and HFC-236ea; then, a material flow containing HFC-245eb and a material flow containing HFC-236ea are obtained through separation; carrying out a reaction on the material flow containing HFC-236ea in the presence of a third catalyst, washing with water, and extracting to obtain a Z-HFO-1225ye material flow and an E-HFO-1225ye material flow; and reacting the material flow containing HFC-245eb in the presence of a fourth catalyst, and washing and separating to obtain the material flow of HFO-1234yf.

The invention relates to the technical field of refrigerant raw material preparation, and discloses a novel energy-saving environment-friendly refrigerant raw material preparation system which comprises a raw material preparation and supply unit, a reaction and separation unit and a refining unit which are connected in sequence, the reaction and separation unit comprises a mixer, a reflux device, a reactor, a cooling separation device, a membrane type absorption device and a tail gas tower which are connected in sequence; the refining unit comprises an azeotropic tower, a rectifying tower I and a rectifying tower II which are connected in sequence, and is used for performing dehydration, deacidification and rectifying purification on the separated crude chlorinated liquid to obtain a high-purity carbon tetrachloride product; by optimizing the technological process of the raw material preparation and supply unit, the reaction and separation unit and the refining unit, efficient, environment-friendly and energy-saving production of carbon tetrachloride is realized; the problem that the production raw material carbon tetrachloride of the fourth-generation refrigerant is insufficient is solved, the production cost is reduced, and the production efficiency is improved.

The invention discloses a device for recovering monochlorodifluoromethane from a preparation system, which is characterized in that a residual liquid outlet is communicated with a recovery buffer tank (2) through a residual liquid storage tank (1), a liquid phase outlet of the residual liquid storage tank (1) is communicated with an inlet of an alkali liquor desorption tower (6) through a regulating valve (3), a material outlet of a dilute acid storage tank (5) is communicated with an inlet of the alkali liquor desorption tower (6), and a material outlet of the dilute acid storage tank (5) is communicated with a material outlet of the alkali liquor desorption tower (6). An alkali liquor outlet is communicated with a recovery buffer tank (2) through an alkali liquor desorption tower (6), a monochlorodifluoromethane outlet of the recovery buffer tank (2) is communicated with an inlet of a condensation collecting tank (9) through a compressor (8), and the condensation collecting tank (9) is communicated with a finished product storage tank (12) through a recovery pump (4), a water alkali washing system and a rectifying tower (11). The monochlorodifluoromethane stored in the recovery buffer tank (2) is conveyed to a water alkali washing system and then put into a rectifying tower (11) to be refined, and the obtained monochlorodifluoromethane finished product is stored in a finished product storage tank (12).

The invention relates to the technical field of tetrafluoroethane production, and discloses a tetrafluoroethane phase separation system which comprises a main phase separator, the main phase separator is connected with a preheater, the preheater is connected with a cooler, the cooler is connected with a circulating pump, and the circulating pump is connected with a buffer tank; the main phase separator is connected with a light phase storage tank, and the light phase storage tank is connected with a light phase delivery pump I and a light phase delivery pump II; the main phase separator is connected with a heavy phase storage tank, and the heavy phase storage tank is connected with a heavy phase delivery pump I and a heavy phase delivery pump II; and the main phase separator is also connected with an online component analyzer, and the online component analyzer can detect the component proportion of each phase of tetrafluoroethane in the phase separator in real time so as to accurately regulate and control the phase separation process according to the detection result. Through a plurality of innovative assemblies and connection modes, the phase separation device has remarkable beneficial effects in the aspects of precise regulation and control of the phase separation process, product purity improvement, impurity removal, energy recycling, heavy phase treatment and the like.

The invention provides a reactor comprising a reaction chamber having a catalytic surface in contact with reactants in said chamber; and a source for passing electrical current through said catalytic surface. The reactor can be used for dehydrohalogentation reactions, such as dehydrochlorination of HCFC-244bb to HFO-1234yf, and for reactions where zero valent metals are employed for catalysis. The invention further provides a process to prepare HFO-1234yf from HCFC-244bb using an electrically heated reaction chamber.

This invention provides a method for storing fluoro-2-butene that minimizes the progression of isomerization reactions during storage. [Solution] General formula C4H x F y Fluoro-2-butene, represented by the general formula where x is between 0 and 7, y is between 1 and 8, and x+y is 8, may or may not contain at least one of chromium, molybdenum, iron, zinc, and aluminum as a metal impurity. This fluoro-2-butene is stored in a container with the sum of the concentrations of chromium, molybdenum, iron, zinc, and aluminum (in the case where it contains these impurities) being 1000 ppb by mass or less.

The utility model discloses green low-carbon water alkaline washing equipment for preparing monochlorodifluoromethane. The green low-carbon water alkaline washing equipment comprises a water washing tower and an alkaline washing tower, the upper end of the water washing tower is communicated with a series pipe, and the other end of the series pipe is communicated with the lower end of the alkaline washing tower; a plurality of grating plates are arranged in the water washing tower and the alkaline washing tower; fillers are arranged on the grating plates; observation windows are arranged on the water washing tower and the alkaline washing tower and are higher than the filler; a heat utilization structure is arranged between the water washing tower and the alkaline washing tower; a waste liquid utilization structure is arranged. According to the utility model, gas led out from the alkaline washing tower enters the heat exchanger to be condensed into liquid, heat release occurs in the process, water in the water storage tank circulates in the heat exchanger, the heat can be utilized and absorbed, the temperature of the water is changed, and the washing effect can be improved when the water enters the water washing and alkaline washing procedure subsequently; and waste liquid flowing out of the water washing tower can be recycled.

The invention relates to a post-treatment method and system for chloromethane synthesis, and the post-treatment method comprises the following steps: cooling a chloromethane crude product prepared in a reaction stage through an economizer, and then carrying out gas-liquid separation in a gas-liquid separator, a connecting pipeline between the economizer and the gas-liquid separator is filled with a water flow which flows in a direction opposite to that of the material, so that the temperature of a gas-phase discharge hole in the top of the gas-liquid separator is controlled to be 90-120 DEG C; the separated liquid phase enters a hydrochloric acid buffer tank with a partition plate, and an oil phase and a water phase are separated out; and washing the separated gas phase with water by a water washing tower, and then drying to obtain a chloromethane product. The economizer, the gas-liquid separator with specific temperature control and the hydrochloric acid buffer tank with the partition plate are arranged between the reaction system and the water scrubber, so that three-phase separation of'oil phase silicide-water phase-gas phase 'is efficiently realized, and the oil phase silicide is separated from the chloromethane crude product and does not enter the water scrubber and other subsequent systems; therefore, the problem of pipeline blockage in a post-treatment system is solved.

The invention discloses a device and a method for treating hexafluoropropylene coarse pyrolysis gas in a hexafluoropropylene preparation process, a quench cooler (1) is sequentially communicated with a carbon powder filter (2) and an external shell I (6), a spiral guide plate I (7) in the external shell I (6) is communicated with the external shell I (6), the spiral guide plate I (7) is communicated with a deacidification treatment unit (28), and the deacidification treatment unit (28) is communicated with a deacidification treatment unit (28). The deacidification treatment unit (28) is communicated with the gas outlet I (9) through a drainage pipe I (10), the dry-type deacidification device (3) is communicated with the external shell II (11), the spiral guide plate II (13) is communicated with the external shell II (11), the spiral guide plate II (13) is communicated with the dehydration treatment unit (29), the dehydration treatment unit (29) is communicated with the gas outlet II (24) through a drainage pipe II (14), and the dry-type deacidification device (3) is communicated with the gas outlet II (24) through a drainage pipe II (14). And the outer shell II (11) is communicated with the film coating powder remover (5). According to the invention, the hexafluoropropylene crude pyrolysis gas is effectively treated and collected.

The invention relates to a method for removing cyclohexane in a low-molecular brominated polystyrene recovery solvent, which comprises the following steps: adding the recovery solvent containing cyclohexane and dichloromethane into a reaction bottle, and then adding a certain amount of fuming sulfuric acid; stirring and reacting for a period of time at a certain reaction temperature; adding water for quenching, standing for layering, washing an organic layer to be neutral, and standing for layering; and rectifying the organic layer, and collecting corresponding fractions. The used fuming sulfuric acid contains excessive sulfur trioxide, the sulfonation capacity is higher, cyclohexane is sulfonated to generate sulfonic acid group cyclohexane, then the sulfonic acid group cyclohexane is removed through water washing, the removal rate is high, the operation is convenient and fast, the cost is low, and the method is suitable for industrial production.