CN114436761B - Method and system for preparing chlorine by catalyzing fluorine-containing hydrogen chloride and adding methane chloride and methane chloride into coproduction - Google Patents
Method and system for preparing chlorine by catalyzing fluorine-containing hydrogen chloride and adding methane chloride and methane chloride into coproduction Download PDFInfo
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- CN114436761B CN114436761B CN202111651233.4A CN202111651233A CN114436761B CN 114436761 B CN114436761 B CN 114436761B CN 202111651233 A CN202111651233 A CN 202111651233A CN 114436761 B CN114436761 B CN 114436761B
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- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 title claims abstract description 107
- 229910000041 hydrogen chloride Inorganic materials 0.000 title claims abstract description 93
- IXCSERBJSXMMFS-UHFFFAOYSA-N hydrogen chloride Substances Cl.Cl IXCSERBJSXMMFS-UHFFFAOYSA-N 0.000 title claims abstract description 93
- FBBDOOHMGLLEGJ-UHFFFAOYSA-N methane;hydrochloride Chemical compound C.Cl FBBDOOHMGLLEGJ-UHFFFAOYSA-N 0.000 title claims abstract description 72
- 239000000460 chlorine Substances 0.000 title claims abstract description 61
- 238000000034 method Methods 0.000 title claims abstract description 57
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 title claims abstract description 56
- 229910052801 chlorine Inorganic materials 0.000 title claims abstract description 56
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 title claims abstract description 38
- 229910052731 fluorine Inorganic materials 0.000 title claims abstract description 38
- 239000011737 fluorine Substances 0.000 title claims abstract description 38
- KRHYYFGTRYWZRS-UHFFFAOYSA-M Fluoride anion Chemical compound [F-] KRHYYFGTRYWZRS-UHFFFAOYSA-M 0.000 claims abstract description 52
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 claims abstract description 39
- 239000007789 gas Substances 0.000 claims abstract description 36
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical class C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims abstract description 28
- 238000007670 refining Methods 0.000 claims abstract description 23
- 238000007038 hydrochlorination reaction Methods 0.000 claims abstract description 22
- 238000005660 chlorination reaction Methods 0.000 claims abstract description 20
- 230000003647 oxidation Effects 0.000 claims abstract description 18
- 238000007254 oxidation reaction Methods 0.000 claims abstract description 18
- 230000003197 catalytic effect Effects 0.000 claims abstract description 17
- 238000011282 treatment Methods 0.000 claims abstract description 15
- 238000007872 degassing Methods 0.000 claims abstract description 14
- KZBUYRJDOAKODT-UHFFFAOYSA-N Chlorine Chemical compound ClCl KZBUYRJDOAKODT-UHFFFAOYSA-N 0.000 claims abstract description 11
- 238000005406 washing Methods 0.000 claims description 13
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 9
- 239000002253 acid Substances 0.000 claims description 5
- 238000001035 drying Methods 0.000 claims description 5
- 238000007906 compression Methods 0.000 claims description 3
- 230000006835 compression Effects 0.000 claims description 3
- 239000000047 product Substances 0.000 abstract description 23
- 239000006227 byproduct Substances 0.000 abstract description 16
- 238000004519 manufacturing process Methods 0.000 abstract description 11
- 238000000926 separation method Methods 0.000 abstract description 9
- 238000005265 energy consumption Methods 0.000 abstract description 7
- 238000004134 energy conservation Methods 0.000 abstract description 4
- 239000003344 environmental pollutant Substances 0.000 abstract description 4
- 231100000719 pollutant Toxicity 0.000 abstract description 4
- 238000006555 catalytic reaction Methods 0.000 abstract description 3
- 230000001737 promoting effect Effects 0.000 abstract description 3
- NEHMKBQYUWJMIP-UHFFFAOYSA-N chloromethane Chemical compound ClC NEHMKBQYUWJMIP-UHFFFAOYSA-N 0.000 description 37
- 238000006243 chemical reaction Methods 0.000 description 25
- HEDRZPFGACZZDS-UHFFFAOYSA-N Chloroform Chemical compound ClC(Cl)Cl HEDRZPFGACZZDS-UHFFFAOYSA-N 0.000 description 14
- YMWUJEATGCHHMB-UHFFFAOYSA-N Dichloromethane Chemical compound ClCCl YMWUJEATGCHHMB-UHFFFAOYSA-N 0.000 description 10
- 239000003054 catalyst Substances 0.000 description 8
- 229960001701 chloroform Drugs 0.000 description 8
- 239000007788 liquid Substances 0.000 description 8
- VZGDMQKNWNREIO-UHFFFAOYSA-N tetrachloromethane Chemical compound ClC(Cl)(Cl)Cl VZGDMQKNWNREIO-UHFFFAOYSA-N 0.000 description 8
- 239000002994 raw material Substances 0.000 description 7
- LCGLNKUTAGEVQW-UHFFFAOYSA-N Dimethyl ether Chemical compound COC LCGLNKUTAGEVQW-UHFFFAOYSA-N 0.000 description 6
- 239000003513 alkali Substances 0.000 description 6
- 238000004064 recycling Methods 0.000 description 5
- 238000009835 boiling Methods 0.000 description 4
- 238000009833 condensation Methods 0.000 description 4
- 230000005494 condensation Effects 0.000 description 4
- VOPWNXZWBYDODV-UHFFFAOYSA-N Chlorodifluoromethane Chemical compound FC(F)Cl VOPWNXZWBYDODV-UHFFFAOYSA-N 0.000 description 3
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- -1 alkaline washing Substances 0.000 description 3
- 230000008901 benefit Effects 0.000 description 3
- 229910052799 carbon Inorganic materials 0.000 description 3
- 238000012824 chemical production Methods 0.000 description 3
- 125000003963 dichloro group Chemical group Cl* 0.000 description 3
- 239000012528 membrane Substances 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- XPDWGBQVDMORPB-UHFFFAOYSA-N Fluoroform Chemical compound FC(F)F XPDWGBQVDMORPB-UHFFFAOYSA-N 0.000 description 2
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000005984 hydrogenation reaction Methods 0.000 description 2
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 238000011084 recovery Methods 0.000 description 2
- 238000001179 sorption measurement Methods 0.000 description 2
- 238000009834 vaporization Methods 0.000 description 2
- 230000008016 vaporization Effects 0.000 description 2
- YZCKVEUIGOORGS-OUBTZVSYSA-N Deuterium Chemical compound [2H] YZCKVEUIGOORGS-OUBTZVSYSA-N 0.000 description 1
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 229940059864 chlorine containing product ectoparasiticides Drugs 0.000 description 1
- NEHMKBQYUWJMIP-OUBTZVSYSA-N chloromethane Chemical group Cl[13CH3] NEHMKBQYUWJMIP-OUBTZVSYSA-N 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000006356 dehydrogenation reaction Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000003814 drug Substances 0.000 description 1
- 230000009977 dual effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000004334 fluoridation Methods 0.000 description 1
- 229910000040 hydrogen fluoride Inorganic materials 0.000 description 1
- 238000005272 metallurgy Methods 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 238000013021 overheating Methods 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-N sulfuric acid Substances OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 1
- 229920002994 synthetic fiber Polymers 0.000 description 1
- 238000005292 vacuum distillation Methods 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C17/00—Preparation of halogenated hydrocarbons
- C07C17/093—Preparation of halogenated hydrocarbons by replacement by halogens
- C07C17/16—Preparation of halogenated hydrocarbons by replacement by halogens of hydroxyl groups
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C17/00—Preparation of halogenated hydrocarbons
- C07C17/38—Separation; Purification; Stabilisation; Use of additives
- C07C17/395—Separation; Purification; Stabilisation; Use of additives by treatment giving rise to a chemical modification of at least one compound
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invention provides a method and a system for preparing chlorine gas by catalyzing fluorine-containing hydrogen chloride and feeding methane chloride and methane chloride into coproduction, which comprises the following steps: (1) Preparing a mixed gas containing chlorine by catalytic oxidation of fluorine-containing hydrogen chloride; (2) Chlorine in the mixed gas and methane chloride from a hydrochlorination reaction system enter a thermal chlorination reaction unit to generate polychlorinated methane and hydrogen chloride, the heavy component, namely the polychlorinated methane, is further refined, and the light component enters the hydrochlorination reaction unit; (3) The hydrogen chloride in the light component reacts with methanol to generate methane chloride, and the methane chloride is purified by degassing and refining to remove fluoride, thus obtaining pure methane chloride. The method solves the problem of high separation energy consumption of subsequent products of chlorine prepared by the treatment of the byproduct hydrogen chloride of the fluoride and the catalysis of the hydrogen chloride, realizes the closed cycle of chlorine in the system, does not cause secondary pollutants, and lays a foundation for promoting the energy conservation, emission reduction and clean production of the fluoride industry.
Description
Technical Field
The invention belongs to the field of chemical production, and relates to a method and a system for preparing chlorine gas by catalyzing fluorine-containing hydrogen chloride and adding methane chloride and methane chloride into the co-production.
Background
Chlorine is an important chemical basic raw material in the industries of chemistry, metallurgy, medicine, synthetic materials and the like. With the continuous increase of the demand of chlorine-containing products, the shortage of chlorine supply is not beneficial to balance the consumption of chlor-alkali simply by developing chlor-alkali industry, and searching for new sources of chlorine becomes an urgent strategy.
In many processes using chlorine as a raw material, hydrogen chloride is by-produced, and the amount of hydrogen chloride by-produced is increasingly increased while the demand for chlorine is increasingly increased. The preparation of chlorine from hydrogen chloride becomes a key to solve the balance of consumption of chlor-alkali, and the method for preparing chlorine from hydrogen chloride can be mainly divided into 3 types: electrolytic, direct and catalytic oxidation processes. The catalytic oxidation method with the advantages of strong adaptability of the hydrogen chloride raw material, low energy consumption, stable operation and the like becomes a hot spot for the development of the technology for preparing chlorine from hydrogen chloride at home and abroad. The method comprises the following steps:
2HCl+1/2O2→Cl2+H2OΔH＝-13.8kcal/mol；
the technology has developed catalytic oxidation catalyst and designed proper fluidized bed reactor for catalytic oxidation process, and the technological process of preparing chlorine through catalytic oxidation of hydrogen chloride has the technological problem of lowering the energy consumption of separating subsequent product gas. The methods commonly used at present mainly comprise a pressure swing adsorption method, a condensation method, a low-temperature rectification method, an absorption-analysis method, a membrane separation method and the like. Chinese patent document CN101128392a (CN 200680005928.2) discloses a method for preparing chlorine, which uses a method of combining condensation method and membrane separation method to recover chlorine in hydrogen chloride catalytic oxidation mixed gas, and the purity of the obtained product chlorine is greater than 95%. But the method has high energy consumption and complex process. Chinese patent document CN101663233a (CN 200880012431.2) discloses a process for the optionally catalyst-assisted oxidation of hydrogen chloride by oxygen, comprising single-stage or multistage cooling of the process gas and separation of unreacted hydrogen chloride and reaction water from the process gas, drying the gas product. However, the method also has the defects of complex equipment and high operation energy consumption. In conclusion, the purity of the product chlorine obtained by the pressure swing adsorption method is not high, and the requirement that the purity of the chlorine for chemical production is more than 99% cannot be met. Although the condensation method, the absorption method, the low-temperature distillation method, the membrane separation method and the coupling method can meet the purity requirement, the energy consumption is high, the process is complex, and the implementation of national energy conservation and emission reduction and sustainable development strategy is not facilitated.
A large amount of fluorine-containing hydrogen chloride can be generated in the fluorine chemical production process, hydrochloric acid is usually generated at present, the byproduct hydrochloric acid is resolved to be a relatively mature recovery process for solving the byproduct hydrogen chloride, hydrogen chloride in the byproduct hydrochloric acid can be recovered, the comprehensive utilization of the byproduct hydrochloric acid is realized, but the process has large investment and high operation cost. The Chinese patent document CN111499490A (202010342702.3) provides a method for producing methane chloride by using byproduct fluorine-containing hydrogen chloride, which uses byproduct hydrogen chloride with higher fluoride content as a raw material for producing methane chloride, obtains a large amount of hydrogen chloride gas reaching reaction conditions by comprehensively treating the byproduct fluorine-containing hydrogen chloride, reacts with methanol, and then obtains high-purity methane chloride through chilling separation, water washing, alkali washing, compression condensation and degassing refining. However, the patent cannot realize the recycling of chlorine element, and has the defects of high investment cost and high operation cost.
Disclosure of Invention
In order to solve the problems of high recycling cost and easy secondary pollutant generation of fluorine-containing hydrogen chloride in the prior art, the invention provides a method and a system for preparing chlorine gas into methane chloride and methane chloride by catalyzing fluorine-containing hydrogen chloride, the method solves the problem of high separation energy consumption of subsequent products of chlorine prepared by the treatment of the byproduct hydrogen chloride of the fluoride and the catalysis of the hydrogen chloride, realizes the closed cycle of chlorine in the system, does not cause secondary pollutants, and lays a foundation for promoting the energy conservation, emission reduction and clean production of the fluoride industry.
In order to achieve the above purpose, the present invention adopts the following technical scheme:
A method for preparing chlorine gas by catalyzing fluorine-containing hydrogen chloride into methane chloride and methane chloride to be coproduced comprises the following steps:
(1) Preparing a mixed gas containing chlorine by catalytic oxidation of fluorine-containing hydrogen chloride;
(2) Chlorine in the mixed gas and methane chloride from a hydrochlorination reaction system enter a thermal chlorination reaction unit to generate polychlorinated methane and hydrogen chloride, the heavy component, namely the polychlorinated methane, is further refined, and the light component enters the hydrochlorination reaction unit;
(3) The hydrogen chloride in the light component reacts with methanol to generate methane chloride, and the methane chloride is purified by degassing and refining to remove fluoride, thus obtaining pure methane chloride. The light component can also go to the step (1) to prepare chlorine.
The content of fluoride in the byproduct hydrogen chloride of the fluoridation chemical industry is generally 2-5%, for example, the preparation of the trifluoromethane (R23) by trichloromethane and HF can generate HCl and byproduct difluoro chloromethane (R22). When the fluoride is in the range, the hydrochlorination and the thermal chlorination are not affected when the fluoride enters a methane chloride and methane chloride co-production process system. When the HF content in the fluoride is too high, the activity of the catalyst in catalytic oxidation is affected to some extent.
According to the invention, the byproduct hydrogen chloride of the fluoride process contains 95-98wt% of hydrogen chloride and 2-5wt% of fluoride, wherein the fluoride is one or a combination of a plurality of R22, R32, R125, R134a, R143a and HF.
And (3) preparing chlorine by catalytic oxidation of fluorine-containing hydrogen chloride, wherein the catalyst and the process adopt the prior art.
According to a preferred embodiment of the present invention, the composition of the mixed gas in step (1): 70-85% of chlorine, 0.5-5% of fluoride and 15-25% of hydrogen chloride.
According to the invention, the reaction conditions of step (2) are preferably: the chlorine and the methane chloride react under the conditions of 395-405 ℃ and 0.55-0.65 MPa, the reaction is a strong exothermic reaction, and the mass ratio of the chlorine to the methane chloride is 2-2.5:1 in order to control the reaction temperature.
And (3) condensing and separating the mixed gas after the reaction in the step (2) by using a second stage, condensing methane chloride, methylene dichloride and the like, enabling the mixed condensate to comprise methane chloride, methylene dichloride, chloroform, carbon tetrachloride and a small amount of fluoride to enter a subsequent refining unit, enabling the mixed condensate to enter a recycling tower, a dichloro refining tower, a chloroform refining tower and a four-carbon refining tower to obtain corresponding qualified products, and enabling the recycling recovery part of the methane chloride to enter the reaction unit to participate in the reaction. The secondary condensing temperatures were 5℃and-25℃respectively.
According to the invention, the components of the light component in the step (2) are as follows: 95-99% of hydrogen chloride, 0.2-3% of fluoride and 0-2% of other components (other components are small amounts of methane chloride, nitrogen and other non-condensable gases), and the light component enters the step (3) to react with methanol to generate methane chloride. The molar ratio of the hydrogen chloride to the methanol is 1-1.2:1.
In the step (3), the chloromethane contains a small amount of water, a small amount of residual HCl and fluoride, and the chloromethane is purified by washing with water, alkaline washing, acid washing, drying, compressing, then entering a degassing and refining unit to remove the fluoride, wherein one part of the chloromethane is sold as a product, and the other part of the chloromethane is used as a raw material and enters a thermal chlorination reaction unit. The acid washing is to use concentrated sulfuric acid to absorb water, dimethyl ether and a small amount of entrained NaOH.
According to the invention, the pressure of the degassing treatment tower is 0.8-1.6 MPa, and the temperature is 30-45 ℃. The light component gas at the top of the degassing tower contains fluoride and a small amount of chloromethane component (the fluoride content is 90-98 percent); the bottom heavy component liquid contains methane chloride and a small amount of fluoride (the methane chloride content is 99%); wherein the light component gas at the top of the tower is sent to an incineration unit for treatment, and the heavy component liquid at the bottom of the tower is sent to a product refining unit.
According to the invention, the pressure of the refining rectifying tower is 0.7-1.0 MPa, the temperature is 35-45 ℃, and pure chloromethane is obtained after refining.
The invention also provides a system for preparing chlorine by catalyzing fluorine-containing hydrogen chloride, which is used for co-production of methane chloride and methane polychloride, and comprises a catalytic oxidation unit, a thermal chlorination reaction unit and a hydrochlorination reaction unit which are sequentially connected;
The light component discharge port of the thermal chlorination reaction unit is connected with the hydrochlorination reaction unit, and the heavy component discharge port is connected with the polychlorinated methane rectifying tower;
the hydrochlorination unit is connected with the light component removing tower and the chloromethane rectifying tower; and a discharge port of the methane chloride rectifying tower is connected with a thermal chlorination reaction unit.
Preferably, the thermal chlorination reaction unit is connected to a catalytic oxidation unit. The obtained fluorine-containing HCl can be recycled for preparing chlorine.
Preferably, the discharge port of the hydrogenation reaction unit is directly connected with the thermal chlorination reaction unit.
The working principle of the system of the invention is as follows: chlorine generated after the catalytic oxidation of fluorine-containing hydrogen chloride enters a thermal chlorination reaction unit and reacts with pure chloromethane from a hydrochlorination reaction system to generate polychlorinated methane and hydrogen chloride; wherein, the polychlorinated methane is refined to obtain a qualified product, the fluorine-containing hydrogen chloride is taken as a raw material to enter a hydrochlorination unit to generate fluorine-containing chloromethane with methanol, and the fluorine-containing chloromethane is subjected to light removal and refining to obtain a pure chloromethane product. The hydrogen chloride generated by the thermal chlorination reaction unit can also be connected with a catalytic oxidation unit, and the obtained fluorine-containing HCl can be recycled for preparing chlorine. The components coming out of the hydrogenation reaction unit mainly comprise chloromethane, a small amount of HCl and fluoride, and the components directly enter the thermal chlorination reaction unit, and can circulate in the system on the premise that the content of the fluoride does not influence hydrochlorination and thermal chlorination, so that the treatment cost is reduced; when the fluoride content reaches a certain degree (the fluoride content is higher than 5%), the hydrochlorination reaction and the thermal chlorination reaction are influenced, and the dehydrorefining is carried out on the hydrochlorination reaction unit product.
The invention has the technical characteristics and beneficial effects that:
1. According to the invention, the mixed gas such as chlorine obtained by catalyzing fluorine-containing hydrogen chloride is put into a methane chloride and polychlorinated methane co-production system, compared with a method for generating hydrochloric acid from fluoride in fluorine chemical industry and analyzing by-product hydrochloric acid, the process investment and the operation cost are greatly reduced.
2. According to the invention, the mixed gas such as chlorine obtained by catalyzing fluorine-containing hydrogen chloride is directly put into a methane chloride and polychlorinated methane co-production system after being compressed, so that purification and separation treatments such as subsequent liquefaction and the like of the mixed gas after catalysis are omitted; meanwhile, fluoride is removed through degassing and refining in subsequent product treatment, so that a qualified product can be obtained, and the method has economic and environmental benefits. The fluoride is removed after the fluorine-containing hydrogen chloride reacts with the methanol, but the fluoride is not removed in other working procedures, because the boiling point of the chloromethane is higher than that of other fluoride except HF, but the hydrogen fluoride is dissolved in water and is easy to remove. The products of other reaction units, namely chlorine and hydrogen chloride, have low boiling points, and fluoride is difficult to remove by dehydrogenation. In addition, the reason for choosing to remove fluoride in this step is that the unit does not generate new HCl, the HCl content in the light component is minimum, and chlorine element can be utilized to the greatest extent; if fluoride is removed in the thermal chlorination reaction unit, part of HCl is newly generated due to the thermal chlorination reaction, at this time, the HCl content in the light component is the same as that in the byproduct HCl, and the content is higher, so that resource waste is caused, and the treatment procedure is increased. If fluoride is removed after the catalytic oxidation unit, at this time, the Cl 2 content is higher, and the boiling point of chlorine is not different from that of fluoride, so that separation is not easy, and the treatment cost is increased.
3. According to the invention, the chlorine and the methane chloride generate the polychlorinated methane and the hydrogen chloride, and the generated hydrogen chloride is taken as a raw material to enter the hydrochlorination unit, so that the closed cycle of chlorine element in a system is realized by generating the methane chloride with methanol, secondary pollutants are not caused, and a foundation is laid for promoting energy conservation, emission reduction and clean production in the fluoride industry.
Drawings
FIG. 1 is a schematic diagram of a dual production process system for preparing chlorine gas by catalyzing fluorine-containing hydrogen chloride and adding methane chloride and methane chloride.
Detailed Description
The invention will now be further illustrated by, but is not limited to, the following examples in conjunction with the accompanying drawings.
Example 1
A method for preparing chlorine gas by catalyzing fluorine-containing hydrogen chloride into a methane chloride and methane polychloride coproduction process comprises the following steps:
(1) Fluorine-containing hydrogen chloride (the hydrogen chloride content is 96.5 percent and the R125 content is 3.5 percent) is catalyzed and oxidized at the reaction temperature of 400 ℃ and the reaction pressure of 0.4MPa by adopting a fixed bed reactor and adopting copper-lanthanum-potassium-oxygen/aluminum oxide as a catalyst, wherein the airspeed is 2200h -1 to obtain a mixed gas containing chlorine, and the gas component is deoxidized and dried: 73.1% of chlorine, 3.5% of R125 and 23.4% of hydrogen chloride.
(2) The mixed gas compressed to 1.0MPa is added into a thermal chlorination reaction unit to generate methylene dichloride, chloroform, carbon tetrachloride and hydrogen chloride (the fluoride content in the light component is 1.4 percent, the hydrogen chloride content is 98.1 percent, and the methane chloride content is 0.5 percent) with methane chloride from the hydrochlorination reaction unit, and the light component enters a hydrochlorination reaction system, wherein the methane chloride is the product of the hydrochlorination reaction system, so that the reaction is not influenced.
Chlorine (Cl 2) and methane chloride (CH 3 Cl) react at 400 ℃ and 0.55MPa to generate the polychlorinated methane, wherein the mass ratio of the chlorine to the methane chloride is 2.2:1.
Separating the products of the polychlorinated methane according to the boiling points of the methylene dichloride, the trichloromethane and the carbon tetrachloride, wherein the temperature of a dichloro tower is 125 ℃, the tower pressure is 0.45MPa, the temperature of a chloroform tower is 110 ℃, the tower pressure is 0.1MPa, the temperature of a four-carbon tower is 75 ℃, and the tower pressure is 0.01MPa, so that the corresponding polychlorinated methane product can be obtained.
(3) The light component (feed pressure 0.35-0.45 MPa, guaranteed to enter the reaction) in the step (2) enters a hydrochlorination reaction system, and is respectively overheated to 210 ℃ with methanol (feed pressure 0.5MPa after methanol vaporization and overheating) and then enters a reactor for reaction. The catalyst is active alumina, the reaction temperature is 230 ℃, the reaction pressure is 0.25Mpa, the product in the reactor is chloromethane, water and excessive HCl (in order to reduce byproducts and obtain better CH 3 OH conversion rate, the molar ratio of the HCl to CH 3 OH is controlled to be 1.15:1, if CH 3 OH is excessive, more dimethyl ether is produced), the gas-liquid mixture of fluoride (R125) and the like is obtained by acid washing, alkali washing, drying and compressing to 0.8MPa, and the mass content of the components in the mixed gas is as follows: 97.7% chloromethane, 2.2% R125 and 0.01% moisture; the mixed gas enters a degassing unit, the tower pressure is 1.0MPa, the temperature is 38 ℃, and the tower top light component gas contains fluoride (96.5%) and a small amount of chloromethane component (3.5%); the bottom heavy component liquid contains methane chloride (98.5%) and small amounts of fluoride; wherein the light component gas at the top of the tower is sent to an incineration unit for treatment, and the heavy component liquid at the bottom of the tower is sent to a product refining unit; the pressure of the methane chloride rectifying tower is 0.9MPa, the temperature is 40 ℃, and the methane chloride with the content of 99.9 percent is obtained after refining.
The fluorine-containing hydrogen chloride is treated according to the method of the invention, and the yield of the fluorine-containing hydrogen chloride treated by 1t is about 100 yuan/t. The existing treatment method is adopted to prepare the hydrochloric acid from the fluorine-containing hydrogen chloride, and the treatment of 1t of hydrogen chloride needs to be carried out at about 300 yuan/t. The method of the invention produces higher economic benefit.
Example 2
A method for preparing chlorine gas by catalyzing fluorine-containing hydrogen chloride into a methane chloride and methane polychloride coproduction process comprises the following steps:
(1) The fluorine-containing hydrogen chloride (the hydrogen chloride content is 95.5%, the R125 and R32 contents are 4.5%) is subjected to catalytic oxidation (the reaction temperature is 400 ℃, the reaction pressure is 0.4MPa, the reactor is a fixed bed reactor, the catalyst is copper-lanthanum-potassium-oxygen/aluminum oxide, the airspeed is 2200h -1) to obtain a mixed gas containing chlorine, and the gas components are deoxidized and dried: chlorine gas 72%, R125 and R32 content 3.6%, hydrogen chloride 24.4%.
(2) Adding the mixed gas compressed to 1.0MPa into a thermal chlorination reaction unit, generating methylene dichloride, chloroform, carbon tetrachloride and hydrogen chloride (the fluoride content is 1.6%, the hydrogen chloride is 97.9% and the methane chloride is 0.5%) with the methane chloride from the hydrochlorination reaction unit,
Chlorine (Cl 2) and methane chloride (CH 3 Cl) react at 400 ℃ and 0.55MPa to generate the polychlorinated methane, wherein the mass ratio of the chlorine to the methane chloride is 2.2:1, a step of; the temperature of the dichloro tower is 125 ℃, the tower pressure is 0.45MPa, the temperature of the chloroform tower is 110 ℃, the tower pressure is 0.1MPa, the temperature of the four-carbon tower is 75 ℃, and the tower pressure is 0.01MPa.
(3) The light component in the step (2) enters a hydrochlorination system, is respectively overheated to 210 ℃ with methanol (the pressure after vaporization is 0.5 MPa), and then enters a reactor for reaction. The catalyst is activated alumina, the reaction temperature is 220 ℃, the reaction pressure is 0.25Mpa, methane chloride is generated in the reactor, at the moment, the components in the reactor are methane chloride, water and excessive HCl (in order to reduce byproducts and obtain better CH 3 OH conversion rate, the molar ratio of the HCl to CH 3 OH is controlled to be 1.1:1, if CH 3 OH is excessive, more dimethyl ether is generated), the gas-liquid mixture of fluoride (R125 and R32) and the like is subjected to acid washing, alkali washing, drying and compression to obtain mixed gas of 0.8MPa, and the mass content of the components in the mixed gas is as follows: 97.2% chloromethane, 2.6% R125 and R32 and 0.02% moisture; the mixed gas enters a degassing unit, the tower pressure is 1.0MPa, the temperature is 38 ℃, and the tower top light component gas contains 96.5% of fluoride and a small amount of chloromethane with the content of 3.5%; the bottom heavy component liquid contains methane chloride (98.3%) and small amounts of fluoride; wherein the light component gas at the top of the tower is sent to an incineration unit for treatment, and the heavy component liquid at the bottom of the tower is sent to a product refining unit; the pressure of the methane chloride rectifying tower is 0.9MPa, the temperature is 40 ℃, and the methane chloride with the content of 99.9 percent is obtained after refining.
Comparative example 1
A method for preparing chlorine gas by catalyzing fluorine-containing hydrogen chloride into a methane chloride and methane polychloride coproduction process comprises the following steps:
Chlorine obtained by catalyzing fluorine-containing hydrogen chloride as described in example 1 was fed into a methane chloride and methane polychloride co-production system, and the difference from example 1 was that: degassing and refining are omitted; other steps and conditions were consistent with example 1, and the resulting chloromethane product was 97.5%, thereby obtaining a qualified product by the process of the present invention as compared with example 1, and also achieving recycling of chlorine.
Methane chloride which is not subjected to degassing and refining treatment can enter a thermal chlorination reaction system to prepare the methane chloride, but when the fluoride content is high, the reaction efficiency is affected, and the consumption of a refining unit is increased.
Claims (5)
1. The method for preparing chlorine gas by catalyzing fluorine-containing hydrogen chloride into methane chloride and methane polychloride for coproduction is characterized by comprising the following steps of:
(1) Preparing a chlorine-containing mixed gas by catalytic oxidation of fluorine-containing hydrogen chloride, wherein the content of fluoride in the fluorine-containing hydrogen chloride is 2-5%, and the mixed gas comprises the following components: 70-85% of chlorine, 0.5-5% of fluoride and 15-25% of hydrogen chloride;
(2) Chlorine in the mixed gas and methane chloride from a hydrochlorination reaction system enter a thermal chlorination reaction unit to generate polychlorinated methane and hydrogen chloride, the heavy component, namely polychlorinated methane, is further refined, the light component enters the hydrochlorination reaction unit, and the components of the light component are as follows: 95-99% of hydrogen chloride, 0.2-3% of fluoride and 0-2% of other fluoride; reacting chlorine and methane chloride at 395-405 ℃ and 0.55-0.65 MPa, wherein the mass ratio of the chlorine to the methane chloride is 2-2.5:1;
(3) Reacting hydrogen chloride in the light component with methanol to generate methane chloride, and removing fluoride after degassing and refining to prepare pure methane chloride; the light component goes to the step (1) to prepare chlorine; the tower pressure of the degassing treatment is 0.8-1.6 MPa, and the temperature is 30-45 ℃.
2. The method of claim 1, wherein the fluoride is a combination of one or more of R22, R32, R125, R134a, R143a, HF.
3. The method of claim 1, wherein the molar ratio of hydrogen chloride to methanol in step (3) is 1-1.2:1.
4. The method according to claim 1, wherein the methane chloride produced in step (3) is first subjected to water washing, alkaline washing, acid washing, drying, compression, and then enters a degassing and refining unit.
5. The method according to claim 1, wherein the pressure of the refining rectifying tower in the step (3) is 0.7-1.0 mpa and the temperature is 35-45 ℃.
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| CN1781888A (en) * | 2004-07-16 | 2006-06-07 | 株式会社德山 | Method for producing methyl chloride and method for producing highly chlorinated methanes |
| CN109607478A (en) * | 2018-12-25 | 2019-04-12 | 西安近代化学研究所 | A kind of technique of step oxidation chlorination hydrogen and hydrogen fluoride gaseous mixture preparing chlorine gas |
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| GB1142351A (en) * | 1965-03-23 | 1969-02-05 | Allied Chem | Process for the production of chloromethanes |
| JPS5231842B2 (en) * | 1973-10-06 | 1977-08-17 | ||
| RU2127245C1 (en) * | 1996-10-23 | 1999-03-10 | Денисов Анатолий Кузьмич | Process for preparing methanic chlorohydrocarbons |
| FR2912403B1 (en) * | 2007-02-13 | 2012-06-22 | Arkema France | PROCESS FOR THE PRODUCTION OF METHYLENE CHLORIDE |
| CN112299947B (en) * | 2020-11-02 | 2022-11-08 | 山东东岳氟硅材料有限公司 | Method for preparing methane chloride by using fluorine chemical byproduct hydrogen chloride |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN1781888A (en) * | 2004-07-16 | 2006-06-07 | 株式会社德山 | Method for producing methyl chloride and method for producing highly chlorinated methanes |
| CN109607478A (en) * | 2018-12-25 | 2019-04-12 | 西安近代化学研究所 | A kind of technique of step oxidation chlorination hydrogen and hydrogen fluoride gaseous mixture preparing chlorine gas |
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| Title |
|---|
| 甲醇法三氯甲烷装置开发设计简介;刘克强;《中国氯碱》(第05期);第30-32, 29页 * |
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