CN111013612A - Preparation method of solid fluorination catalyst - Google Patents
Preparation method of solid fluorination catalyst Download PDFInfo
- Publication number
- CN111013612A CN111013612A CN201911325891.7A CN201911325891A CN111013612A CN 111013612 A CN111013612 A CN 111013612A CN 201911325891 A CN201911325891 A CN 201911325891A CN 111013612 A CN111013612 A CN 111013612A
- Authority
- CN
- China
- Prior art keywords
- catalyst
- chromium
- fluorination
- fluorination catalyst
- preparing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000003054 catalyst Substances 0.000 title claims abstract description 94
- 238000003682 fluorination reaction Methods 0.000 title claims abstract description 55
- 239000007787 solid Substances 0.000 title claims abstract description 26
- 238000002360 preparation method Methods 0.000 title claims abstract description 18
- PHFQLYPOURZARY-UHFFFAOYSA-N chromium trinitrate Chemical compound [Cr+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O PHFQLYPOURZARY-UHFFFAOYSA-N 0.000 claims abstract description 46
- XPDWGBQVDMORPB-UHFFFAOYSA-N Fluoroform Chemical compound FC(F)F XPDWGBQVDMORPB-UHFFFAOYSA-N 0.000 claims abstract description 30
- 238000000034 method Methods 0.000 claims abstract description 19
- 239000012018 catalyst precursor Substances 0.000 claims abstract description 18
- 229910021555 Chromium Chloride Inorganic materials 0.000 claims abstract description 14
- QSWDMMVNRMROPK-UHFFFAOYSA-K chromium(3+) trichloride Chemical compound [Cl-].[Cl-].[Cl-].[Cr+3] QSWDMMVNRMROPK-UHFFFAOYSA-K 0.000 claims abstract description 14
- 239000002244 precipitate Substances 0.000 claims abstract description 14
- 238000001035 drying Methods 0.000 claims abstract description 13
- 239000012266 salt solution Substances 0.000 claims abstract description 13
- 239000000243 solution Substances 0.000 claims abstract description 9
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 7
- 239000012752 auxiliary agent Substances 0.000 claims abstract description 4
- 239000008367 deionised water Substances 0.000 claims abstract description 3
- 229910021641 deionized water Inorganic materials 0.000 claims abstract description 3
- 239000000203 mixture Substances 0.000 claims abstract description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 28
- 239000007789 gas Substances 0.000 claims description 16
- 229910052757 nitrogen Inorganic materials 0.000 claims description 13
- ONDPHDOFVYQSGI-UHFFFAOYSA-N zinc nitrate Chemical compound [Zn+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O ONDPHDOFVYQSGI-UHFFFAOYSA-N 0.000 claims description 8
- 238000001354 calcination Methods 0.000 claims description 5
- 239000012299 nitrogen atmosphere Substances 0.000 claims description 5
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 claims description 4
- 238000001816 cooling Methods 0.000 claims description 4
- QGZKDVFQNNGYKY-UHFFFAOYSA-N ammonia Natural products N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims 1
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 abstract description 25
- 230000000694 effects Effects 0.000 abstract description 16
- 229910052804 chromium Inorganic materials 0.000 abstract description 14
- 239000011651 chromium Substances 0.000 abstract description 14
- 239000003153 chemical reaction reagent Substances 0.000 abstract description 8
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 abstract description 7
- 229910000040 hydrogen fluoride Inorganic materials 0.000 abstract description 6
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 abstract description 3
- -1 heat release is high Substances 0.000 abstract description 3
- 239000001301 oxygen Substances 0.000 abstract description 3
- 229910052760 oxygen Inorganic materials 0.000 abstract description 3
- 238000005245 sintering Methods 0.000 abstract description 3
- 229910002651 NO3 Inorganic materials 0.000 abstract description 2
- NHNBFGGVMKEFGY-UHFFFAOYSA-N nitrate group Chemical group [N+](=O)([O-])[O-] NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 abstract description 2
- MWUXSHHQAYIFBG-UHFFFAOYSA-N Nitric oxide Chemical compound O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 abstract 3
- 238000000354 decomposition reaction Methods 0.000 abstract 1
- 238000006243 chemical reaction Methods 0.000 description 14
- 238000004334 fluoridation Methods 0.000 description 6
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 description 5
- 230000001276 controlling effect Effects 0.000 description 5
- 239000011737 fluorine Substances 0.000 description 5
- 229910052731 fluorine Inorganic materials 0.000 description 5
- 239000012716 precipitator Substances 0.000 description 5
- 230000003197 catalytic effect Effects 0.000 description 4
- 239000000047 product Substances 0.000 description 4
- WGLPBDUCMAPZCE-UHFFFAOYSA-N Trioxochromium Chemical compound O=[Cr](=O)=O WGLPBDUCMAPZCE-UHFFFAOYSA-N 0.000 description 3
- 235000011114 ammonium hydroxide Nutrition 0.000 description 3
- 239000000460 chlorine Substances 0.000 description 3
- 229910000423 chromium oxide Inorganic materials 0.000 description 3
- JOPOVCBBYLSVDA-UHFFFAOYSA-N chromium(6+) Chemical compound [Cr+6] JOPOVCBBYLSVDA-UHFFFAOYSA-N 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 230000003647 oxidation Effects 0.000 description 3
- 238000007254 oxidation reaction Methods 0.000 description 3
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 2
- 230000003213 activating effect Effects 0.000 description 2
- 239000003513 alkali Substances 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 2
- 239000012298 atmosphere Substances 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 239000007795 chemical reaction product Substances 0.000 description 2
- 229910052801 chlorine Inorganic materials 0.000 description 2
- KYKAJFCTULSVSH-UHFFFAOYSA-N chloro(fluoro)methane Chemical group F[C]Cl KYKAJFCTULSVSH-UHFFFAOYSA-N 0.000 description 2
- 238000004587 chromatography analysis Methods 0.000 description 2
- 229910021563 chromium fluoride Inorganic materials 0.000 description 2
- VQWFNAGFNGABOH-UHFFFAOYSA-K chromium(iii) hydroxide Chemical compound [OH-].[OH-].[OH-].[Cr+3] VQWFNAGFNGABOH-UHFFFAOYSA-K 0.000 description 2
- RWRIWBAIICGTTQ-UHFFFAOYSA-N difluoromethane Chemical compound FCF RWRIWBAIICGTTQ-UHFFFAOYSA-N 0.000 description 2
- 229910001873 dinitrogen Inorganic materials 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- LVGUZGTVOIAKKC-UHFFFAOYSA-N 1,1,1,2-tetrafluoroethane Chemical compound FCC(F)(F)F LVGUZGTVOIAKKC-UHFFFAOYSA-N 0.000 description 1
- PGJHURKAWUJHLJ-UHFFFAOYSA-N 1,1,2,3-tetrafluoroprop-1-ene Chemical compound FCC(F)=C(F)F PGJHURKAWUJHLJ-UHFFFAOYSA-N 0.000 description 1
- TWRXJAOTZQYOKJ-UHFFFAOYSA-L Magnesium chloride Chemical compound [Mg+2].[Cl-].[Cl-] TWRXJAOTZQYOKJ-UHFFFAOYSA-L 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 229910001430 chromium ion Inorganic materials 0.000 description 1
- QCMJBECJXQJLIL-UHFFFAOYSA-L chromium(6+);oxygen(2-);difluoride Chemical compound [O-2].[O-2].[F-].[F-].[Cr+6] QCMJBECJXQJLIL-UHFFFAOYSA-L 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- GTLACDSXYULKMZ-UHFFFAOYSA-N pentafluoroethane Chemical compound FC(F)C(F)(F)F GTLACDSXYULKMZ-UHFFFAOYSA-N 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 239000002341 toxic gas Substances 0.000 description 1
- FTBATIJJKIIOTP-UHFFFAOYSA-K trifluorochromium Chemical compound F[Cr](F)F FTBATIJJKIIOTP-UHFFFAOYSA-K 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- 239000011701 zinc Substances 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
- B01J37/22—Halogenating
- B01J37/26—Fluorinating
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J27/00—Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
- B01J27/06—Halogens; Compounds thereof
- B01J27/132—Halogens; Compounds thereof with chromium, molybdenum, tungsten or polonium
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
- B01J37/02—Impregnation, coating or precipitation
- B01J37/03—Precipitation; Co-precipitation
- B01J37/031—Precipitation
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
- B01J37/08—Heat treatment
- B01J37/082—Decomposition and pyrolysis
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
- B01J37/12—Oxidising
- B01J37/14—Oxidising with gases containing free oxygen
-
- 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
- C07C17/20—Preparation of halogenated hydrocarbons by replacement by halogens of halogen atoms by other halogen atoms
- C07C17/202—Preparation of halogenated hydrocarbons by replacement by halogens of halogen atoms by other halogen atoms two or more compounds being involved in the reaction
- C07C17/206—Preparation of halogenated hydrocarbons by replacement by halogens of halogen atoms by other halogen atoms two or more compounds being involved in the reaction the other compound being HX
Abstract
The invention provides a preparation method of a solid fluorination catalyst, which comprises the following steps: dissolving a mixture of chromium chloride and chromium nitrate and an auxiliary agent in deionized water to obtain a mixed salt solution; adding the obtained mixed salt solution into a precipitant solution, controlling the pH of the system to precipitate the salt solution, collecting and drying the precipitate, and roasting in different atmospheres in sections to obtain a catalyst precursor; and tabletting and forming the obtained catalyst precursor, and then fluorinating the catalyst precursor by using trifluoromethane to obtain the fluorination catalyst. According to the method, nitrogen oxide generated by decomposition of nitrate during roasting and oxygen in air are utilized to oxidize trivalent chromium to a certain extent, the valence of chromium can be improved, and meanwhile, trifluoromethane is used as a fluorination reagent, so that the problems that hydrogen fluoride reacts violently as a common fluorination reagent, heat release is high, and catalyst sintering is easily caused can be effectively avoided. The catalyst prepared by the method is used for preparing R134a and R125, and has the advantage of high activity.
Description
Technical Field
The invention relates to a preparation method of a solid fluorination catalyst, in particular to a catalyst for producing difluoromethane, tetrafluoroethane, pentafluoroethane and tetrafluoropropene products, belonging to the technical field of catalyst preparation.
Background
The chlorofluorocarbon exchange reaction is a key reaction step in the preparation of chlorofluorocarbons. The existing chlorofluorocarbon products mainly depend on solid gas phase fluorination catalysts, and the catalysts used at the present stage are generally chromium-based catalysts taking chromium element as a main active component, and certain catalyst performance is improved by adding auxiliary metals. For example, EP0502605 discloses a method of increasing the catalyst activity by adding an auxiliary metal such as Co, Ni, Zn, or the like.
In the case of fluorination catalysts, the activity of the catalyst is closely related to the structure formed by fluorination of the catalyst and the valence of chromium in the catalyst. Patent document US6433233 teaches that the valence of chromium is between 3.5 and 5.0, which contributes to the increase in catalyst activity. It is also disclosed in US5849658 that the catalytic activity of the catalyst has a considerable relationship with its surface area, with a higher specific surface area contributing to an increase in the activity of the catalyst.
Many studies show that trivalent chromium fluoride has a small effect on the exchange reaction of fluorine and chlorine, while hexavalent chromium fluoride runs off too fast, and the service life of the catalyst is short. Therefore, in order to ensure the catalytic activity of the chromium-based catalyst, the valence state of the chromium element needs to be strictly regulated and controlled. In the prior art, chlorine or oxygen and the like are generally used for oxidizing the chromium-based catalyst, but the oxidation effect is not ideal, and the activity of the obtained catalyst is low. Therefore, in order to obtain a high valence state chromium-based catalyst, there is a patent report on activating the catalyst with fluorine gas. For example: chinese patent document CN106824232A provides a high-valence chromium-based catalyst, a preparation method and use thereof, the high-valence chromium-based catalyst is composed of high-valence chromium ions and an auxiliary agent, the method is to prepare the high-valence chromium-based catalyst by calcining a catalyst precursor and activating in fluorine gas. However, fluorine gas is a highly dangerous and highly toxic gas, and huge potential safety hazards exist in the transportation, storage and use processes of the fluorine gas. Simultaneously, hydrogen fluoride is chooseed for use to current fluorination reaction reagent, and hydrogen fluoride is difficult to control, and the reaction is violent, causes the catalyst sintering because the reaction is too violent exothermic easily to make the catalyst have the risk that the activity reduces, and hydrogen fluoride has stronger corrosivity, and is great to equipment damage, easily causes the corruption to reveal, and the security is lower.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a preparation method of a solid fluorination catalyst. The preparation method can effectively realize that the chromium element in the chromium-based catalyst has higher valence, simultaneously avoids the problem that the catalyst is easy to sinter in the hydrofluoride fluorination process, and the fluorination catalyst obtained by the invention has higher activity.
The technical scheme of the invention is as follows:
a preparation method of a solid fluorination catalyst comprises the following steps:
(1) dissolving a mixture of chromium chloride and chromium nitrate and an auxiliary agent in deionized water to obtain a mixed salt solution;
(2) adding the mixed salt solution obtained in the step (1) into a precipitant solution, controlling the pH value of the system to precipitate the salt solution, collecting and drying the precipitate, and roasting the precipitate in different atmospheres in sections to obtain a catalyst precursor;
(3) and (3) tabletting and forming the catalyst precursor obtained in the step (2), and then fluorinating the catalyst precursor by using trifluoromethane to obtain the fluorination catalyst.
According to the present invention, it is preferable that the mass ratio of the chromium nitrate to the chromium chloride in the step (1) is 0.1 to 12: 1, more preferably 3 to 10: 1. the ratio of the chromium nitrate to the chromium chloride is controlled within the range, so that the valence state of chromium can be ensured to be 3-6, and if the content of the chromium nitrate is too high or the chromium nitrate is completely chromium nitrate, the chromium element is over oxidized, the hexavalent chromium is excessive, the loss of the catalyst is easy to cause, and the service life of the catalyst is shortened; meanwhile, if the content of the chromium nitrate is too low, the oxidation degree of the chromium element is low, and the activity of the obtained catalyst is low.
According to the invention, preferably, the assistant in the step (1) is zinc nitrate, and the addition amount of the assistant is 10% of the total mass of the chromium chloride and the chromium nitrate.
According to the invention, preferably, the precipitant solution in step (2) is 5-15% ammonia water by mass;
preferably, the pH value of the system is controlled to be 7-9.
According to the present invention, it is preferable that the drying temperature in the step (2) is 90 to 110 ℃ and the drying time is 5 to 8 hours.
According to the present invention, preferably, the step of the staged firing in the step (2) is: firstly, roasting the dried precipitate for 5-7h at the temperature of 250-450 ℃ in nitrogen, and then roasting for 5-7h at the temperature of 300-450 ℃ in mixed gas of air and nitrogen;
further preferably, the volume ratio of air to nitrogen in the mixed gas is 2-10: 1.
according to the present invention, preferably, the fluorination step in step (3) is: drying the catalyst precursor subjected to tabletting molding in a nitrogen atmosphere at 300 ℃ for 20-30h, introducing trifluoromethane, fluorinating at 300 ℃ for 80-120h, and naturally cooling to room temperature to obtain a fluorination catalyst;
further preferably, the flow rate of the trifluoromethane is 100-800mL/min, and more preferably 200-500 mL/min;
more preferably, the fluorination time is 100 h.
The invention has the following technical characteristics and beneficial effects:
1. the preparation method of the invention adds chromium nitrate into chromium chloride to react with precipitator to obtain hydrogenNitrate ions exist in the chromium oxide precipitate, the obtained chromium hydroxide precipitate is firstly roasted in a nitrogen atmosphere, the chromium hydroxide precipitate is fully pyrolyzed to obtain chromium oxide, meanwhile, nitrate is decomposed at high temperature to generate oxynitride, the generated oxynitride has certain oxidizability, and the chromium oxide is oxidized to a certain degree; and the subsequent calcination is carried out in the mixed gas of air and nitrogen, and the oxygen further oxidizes the chromium element, so that the chromium element in the catalyst has higher valence. By H in FIG. 12The TPR curve shows that the catalyst has an obvious low-temperature reduction peak, which indicates that the chromium element in the catalyst has higher valence, thereby improving the catalytic activity of the catalyst.
2. In the preparation method, the proportion of the chromium nitrate and the chromium chloride is strictly controlled, the valence state of the chromium is ensured to be 3-6, and if the content of the chromium nitrate is too high or the chromium nitrate is completely chromium nitrate, the chromium element is over oxidized, the hexavalent chromium is excessive, the loss of the catalyst is easy to cause, and the service life of the catalyst is shortened; if the content of chromium nitrate is too low, the oxidation degree of chromium element is low, and the activity of the obtained catalyst is low.
3. According to the preparation method, trifluoromethane is adopted to replace a traditional fluoridation reagent HF in the fluoridation process, so that the problem that catalyst sintering is possibly caused by violent heat release due to fluoridation is avoided, the chromium oxyfluoride fluoridation catalyst with a certain high valence state is prepared, and the obtained fluoridation catalyst has high catalytic activity; meanwhile, the hydrogen fluoride has strong corrosivity, great damage is caused to equipment, corrosion leakage is easily caused, and the safety is high because the traditional fluoridation reagent HF is replaced by the trifluoromethane.
Drawings
FIG. 1 is H of the solid fluorination catalyst obtained in example 12-TPR curve.
Detailed Description
The present invention is further illustrated by, but is not limited to, the following specific examples.
Meanwhile, the experimental methods described in the following examples are all conventional methods unless otherwise specified; the reagents and materials are commercially available, unless otherwise specified.
Example 1
A preparation method of a solid fluorination catalyst comprises the following steps:
dissolving 15g of chromium chloride and 75g of chromium nitrate in 1L of water, adding 9g of zinc nitrate, continuously and uniformly stirring to prepare a mixed salt solution, preparing 170g of ammonia water with the mass fraction of 10% as a precipitator solution, uniformly adding the mixed salt solution into the precipitator solution, controlling the pH value of the system to be 8, filtering and collecting precipitates, and drying at 100 ℃ for 6 hours. The dried precipitate was placed in a tubular muffle furnace at N2Roasting for 6h at 300 ℃ in the atmosphere, then roasting for 6h at 300 ℃ in a mixed gas of air and nitrogen, wherein the volume ratio of the air to the nitrogen in the mixed gas is 5:1, obtaining a catalyst precursor, tabletting and forming the catalyst precursor, then putting the catalyst precursor into a reaction tube for fluorination, drying for 24h in the nitrogen atmosphere at 300 ℃, then introducing trifluoromethane (R23) according to the flow of 300mL/min, fluorinating for 100h at 300 ℃, and naturally cooling to room temperature, thus obtaining the fluorination catalyst A.
H of the solid fluorination catalyst prepared in this example2The TPR curve is shown in figure 1, and as can be seen from figure 1, the catalyst has a distinct low-temperature reduction peak, which indicates that the chromium element in the catalyst has a higher valence.
Example 2
A solid fluorination catalyst was prepared as described in example 1, except that 75g of chromium chloride and 15g of chromium nitrate were used to obtain fluorination catalyst B.
Example 3
A method of making a solid fluorination catalyst, as in example 1, except that the volume ratio of air to nitrogen in the mixed gas was 3:1 during calcination, gave fluorination catalyst C.
Example 4
A method of making a solid fluorination catalyst was conducted as described in example 1, except that trifluoromethane was controlled to flow 500mL/min to provide fluorination catalyst D.
Example 5
A method of preparing a solid fluorination catalyst, as described in example 2, except that the volume ratio of air to nitrogen in the mixed gas during calcination was 3:1, the fluorination catalyst E was obtained.
Example 6
A method of making a solid fluorination catalyst, as described in example 2, except that trifluoromethane was controlled at 500mL/min, gave fluorination catalyst F.
Comparative example 1
A preparation method of a solid fluorination catalyst comprises the following steps:
dissolving 90g of chromium chloride in 1L of water, adding 9g of zinc nitrate, continuously and uniformly stirring to prepare a mixed salt solution, preparing 185g of ammonia water with the mass fraction of 10% as a precipitator solution, uniformly adding the mixed salt solution into the precipitator solution, controlling the pH value of the system to be 8, filtering, collecting precipitates and drying at 100 ℃ for 6 hours. The dried precipitate was placed in a tubular muffle furnace at N2Roasting for 6h at 300 ℃ in the atmosphere, then roasting for 6h at 300 ℃ in a mixed gas of air and nitrogen, wherein the volume ratio of the air to the nitrogen in the mixed gas is 5:1, obtaining a catalyst precursor, tabletting and forming the catalyst precursor, then putting the catalyst precursor into a reaction tube for fluorination, drying for 24h in the nitrogen atmosphere at 300 ℃, then introducing trifluoromethane (R23) according to the flow of 300mL/min, fluorinating for 100h at 300 ℃, and then naturally cooling to room temperature, thus obtaining the fluorination catalyst G.
Test example 1
100mL of the catalysts prepared in examples 1 to 6 and comparative example 1 were charged in a stainless steel tube of 316L material, 1 meter long DN25, respectively, and the catalysts were fixed in the middle, purged with nitrogen gas at 300 ℃ for 4 hours, respectively, and then HF and R133a (CF) were introduced, respectively3CH2Cl), controlling the molar ratio of HF to R133a to be 8:1, controlling the reaction temperature to be 350 ℃, carrying out certain reaction under the conditions, washing the reaction product by water and alkali to remove HCl and HF, and carrying out product component analysis by chromatography, wherein the results are shown in Table 1.
TABLE 1 preparation of R134a (CF) for different catalyst pairs3CH2F) Influence of (2)
| Numbering | Conversion (%) -R133 a | R134a Selectivity (%) |
| A | 33.78 | 98.21 |
| B | 26.72 | 96.32 |
| C | 28.54 | 97.21 |
| D | 33.21 | 98.23 |
| E | 27.35 | 96.24 |
| F | 29.32 | 97.51 |
| G | 24.37 | 98.41 |
Test example 2
Examples 1 to 6 and pairs100mL of the catalyst prepared in the ratio 1 was loaded in a material 316L, 1 m long DN25 stainless steel tube, respectively. The catalyst was fixed in the middle, purged with nitrogen gas at 300 ℃ for 4 hours, and then HF and R124 (C) were introduced separately2HClF4) The reaction is carried out under the conditions that the molar ratio of HF to R124 is controlled to be 8:1 and the reaction temperature is 350 ℃, the reaction product is washed by water and alkali to remove HCl and HF, and then the product component analysis is carried out by chromatography, and the result is shown in Table 2.
TABLE 2 preparation of R125 (CHF) with different catalyst pairs2CF3) Influence of (2)
As can be seen from tables 1 and 2, the catalyst prepared by adding chromium nitrate to chromium chloride has higher activity, particularly, when the chromium nitrate content is higher, the fluorination catalyst has higher activity, while the catalyst prepared by not adding chromium nitrate in comparative example 1 has lower activity. According to thermodynamic calculation, the conversion rate of R134a prepared by catalyzing R133a by the fluorination catalyst is not more than 35% theoretically, and the catalyst prepared by the method has the similar conversion rate and higher activity.
The method uses the trifluoromethane as the fluorination reagent, can effectively avoid the problems that the hydrogen fluoride reacts violently as the common fluorination reagent, and the heat release is high, so that the catalyst is easy to sinter, and is beneficial to improving the stability of the catalyst.
Claims (10)
1. A preparation method of a solid fluorination catalyst comprises the following steps:
(1) dissolving a mixture of chromium chloride and chromium nitrate and an auxiliary agent in deionized water to obtain a mixed salt solution;
(2) adding the mixed salt solution obtained in the step (1) into a precipitant solution, controlling the pH value of the system to precipitate the salt solution, collecting and drying the precipitate, and roasting the precipitate in different atmospheres in sections to obtain a catalyst precursor;
(3) and (3) tabletting and forming the catalyst precursor obtained in the step (2), and then fluorinating the catalyst precursor by using trifluoromethane to obtain the fluorination catalyst.
2. The method for preparing a solid fluorination catalyst according to claim 1, wherein the mass ratio of the chromium nitrate to the chromium chloride in step (1) is from 0.1 to 12: 1, preferably 3 to 10: 1.
3. the method for preparing a solid fluorination catalyst according to claim 1, wherein the auxiliary in step (1) is zinc nitrate, and the addition amount of the auxiliary is 10% of the total mass of the chromium chloride and the chromium nitrate.
4. The method for preparing a solid fluorination catalyst according to claim 1, wherein the precipitant solution in the step (2) is 5 to 15% by mass of aqueous ammonia.
5. The method for preparing a solid fluorination catalyst according to claim 1, wherein the pH of the system is controlled to 7 to 9 in the step (2).
6. The method for preparing a solid fluorination catalyst according to claim 1, wherein the drying temperature in the step (2) is 90 to 110 ℃ and the drying time is 5 to 8 hours.
7. The method for preparing a solid fluorination catalyst according to claim 1, wherein the step of calcining in stages (2) is: firstly, the dried precipitate is roasted for 5-7h at the temperature of 250-450 ℃ in nitrogen, and then is roasted for 5-7h at the temperature of 300-450 ℃ in mixed gas of air and nitrogen.
8. The method for preparing a solid fluorination catalyst according to claim 7, wherein the volume ratio of air to nitrogen in the mixed gas is 2-10: 1.
9. the method for preparing a solid fluorination catalyst according to claim 1, wherein the fluorination step in the step (3) is: drying the catalyst precursor after tabletting and forming in a nitrogen atmosphere at 300 ℃ for 20-30h, introducing trifluoromethane, fluorinating at 300 ℃ for 80-120h, and naturally cooling to room temperature to obtain the fluorination catalyst.
10. The method for preparing a solid fluorination catalyst as claimed in claim 9, wherein the flow rate of the trifluoromethane is 100-800mL/min, preferably 200-500 mL/min; the fluorination time is 100 h.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911325891.7A CN111013612B (en) | 2019-12-20 | 2019-12-20 | Preparation method of solid fluorination catalyst |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911325891.7A CN111013612B (en) | 2019-12-20 | 2019-12-20 | Preparation method of solid fluorination catalyst |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111013612A true CN111013612A (en) | 2020-04-17 |
| CN111013612B CN111013612B (en) | 2022-12-06 |
Family
ID=70212224
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911325891.7A Active CN111013612B (en) | 2019-12-20 | 2019-12-20 | Preparation method of solid fluorination catalyst |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111013612B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115518632A (en) * | 2022-11-28 | 2022-12-27 | 山东东岳化工有限公司 | Process for preparing hexafluoroethane from pentafluoro-chloroethane and catalyst used in process |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1098332A (en) * | 1993-06-18 | 1995-02-08 | 昭和电工株式会社 | Fluorination catalyst and fluorination process |
| CN1105951A (en) * | 1993-09-07 | 1995-08-02 | 昭和电工株式会社 | Chromium-based fluorination catalyst, process for producing the catalyst, and fluorination process using the catalyst |
| CN101175564A (en) * | 2005-04-08 | 2008-05-07 | 英尼奥斯弗罗控股有限公司 | Chromia based fluorination catalyst |
| US20080207963A1 (en) * | 2007-02-23 | 2008-08-28 | Velliyur Nott Mallikarjuna Rao | Preparation of composition containing chromium, oxygen, and either silver or palladium, and their use as catalysts and catalyst precursors |
| CN103143344A (en) * | 2011-12-06 | 2013-06-12 | 中化蓝天集团有限公司 | Chromium-based fluorination catalyst with high specific surface, and preparation method thereof |
| CN104826638A (en) * | 2015-04-22 | 2015-08-12 | 浙江师范大学 | Preparation method of catalyst for gas phase fluorination reaction |
| CN109261142A (en) * | 2018-09-18 | 2019-01-25 | 山东东岳化工有限公司 | A kind of catalyst and preparation method thereof preparing tetrafluoroethene and hexafluoropropene for fluoroform catalytic pyrolysis |
-
2019
- 2019-12-20 CN CN201911325891.7A patent/CN111013612B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1098332A (en) * | 1993-06-18 | 1995-02-08 | 昭和电工株式会社 | Fluorination catalyst and fluorination process |
| CN1105951A (en) * | 1993-09-07 | 1995-08-02 | 昭和电工株式会社 | Chromium-based fluorination catalyst, process for producing the catalyst, and fluorination process using the catalyst |
| CN101175564A (en) * | 2005-04-08 | 2008-05-07 | 英尼奥斯弗罗控股有限公司 | Chromia based fluorination catalyst |
| US20080207963A1 (en) * | 2007-02-23 | 2008-08-28 | Velliyur Nott Mallikarjuna Rao | Preparation of composition containing chromium, oxygen, and either silver or palladium, and their use as catalysts and catalyst precursors |
| CN103143344A (en) * | 2011-12-06 | 2013-06-12 | 中化蓝天集团有限公司 | Chromium-based fluorination catalyst with high specific surface, and preparation method thereof |
| CN104826638A (en) * | 2015-04-22 | 2015-08-12 | 浙江师范大学 | Preparation method of catalyst for gas phase fluorination reaction |
| CN109261142A (en) * | 2018-09-18 | 2019-01-25 | 山东东岳化工有限公司 | A kind of catalyst and preparation method thereof preparing tetrafluoroethene and hexafluoropropene for fluoroform catalytic pyrolysis |
Non-Patent Citations (2)
| Title |
|---|
| HAN WENFENG ET AL.: ""Catalytic hydrolysis of trifluoromethane over alumina"", 《GHG》 * |
| 钟光祥: "气固相氟化催化剂的研究进展", 《有机氟工业》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115518632A (en) * | 2022-11-28 | 2022-12-27 | 山东东岳化工有限公司 | Process for preparing hexafluoroethane from pentafluoro-chloroethane and catalyst used in process |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111013612B (en) | 2022-12-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109999788B (en) | High-valence metal fluorination catalyst, preparation method and application | |
| TWI341748B (en) | Method for regenerating catalyst for the production of methacrylic acid and process for preparing methacrylic acid | |
| JPH09220469A (en) | Catalyst using chromium oxide as base, its production and application for fluorination of halogenated hydrocarbon | |
| CN104475080B (en) | A kind of mesoporous chromium oxide-based catalyst for de-hydrogen halide | |
| TW201004704A (en) | Method for regenerating catalyst for the production of methacrylic acid and process for preparing methacrylic acid | |
| WO2016078226A1 (en) | Magnesium fluoride-based catalyst and use therefor | |
| CN106588563A (en) | Preparation method of 1,1-difluoroethylene | |
| CN102836722B (en) | Catalyst used in preparation of fluorine-containing olefin through dehydrohalogenation of halohydrofluoroalkane and preparation method of catalyst | |
| CN100372607C (en) | Florination catalyst, its manufacturing method and use | |
| CN111013612B (en) | Preparation method of solid fluorination catalyst | |
| CN100586564C (en) | Chromium base fluorating catalyst and preparation thereof | |
| TW200950882A (en) | Method for regenerating catalyst for the production of methacrylic acid and process for preparing methacrylic acid | |
| CN107570181B (en) | A kind of preparation method of fluorination catalyst | |
| JP5761710B2 (en) | Ammonia decomposition method and method for regenerating catalyst for ammonia decomposition | |
| WO2010149286A1 (en) | Catalyst for chlorine production comprising a copper aluminate of the spinel type | |
| JP2023505582A (en) | Method for Improving Catalyst Stability in HFC-23 Recycling | |
| CN110756201A (en) | Preparation method of carbon structure limited domain metal fluoride | |
| CN109499589B (en) | Chromium-free environment-friendly catalyst for gas-phase fluorination synthesis of 1,1,1,3,3, 3-hexafluoro-2-butene | |
| CN111217669B (en) | Method for preparing vinylidene fluoride through resource conversion of trifluoromethane | |
| CN109718813B (en) | Chromium-free environment-friendly catalyst for gas-phase fluorination synthesis of 3,3, 3-trifluoropropene | |
| CN111635291B (en) | Preparation process of monochlorodifluoromethane | |
| CN110975855B (en) | Catalyst for preparing tetrafluoroethylene and hexafluoropropylene by catalytic pyrolysis of difluoro-chloromethane, preparation method and application thereof | |
| CN111036225B (en) | Method for preparing high-activity pentafluoroethane chromium-based catalyst through sectional roasting and sectional fluorination | |
| KR20180121730A (en) | Acid-resistant catalyst for decomposing perfluorinated compounds having increased forming strength and use thereof | |
| CN111558386B (en) | Ferric fluoride-based catalyst for synthesizing hydro-fluoroolefin by gas phase fluorination, preparation method and application thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20240111 Address after: 1399 Gongye Road, Tangshan Town, Huantai County, Zibo City, Shandong Province, 256400 Patentee after: Shandong Dongyue Green Cold Technology Co.,Ltd. Address before: 256401 Tangshan Town, Huantai County, Zibo City, Shandong Province Patentee before: SHANDONG DONGYUE CHEMICAL Co.,Ltd. |
|
| TR01 | Transfer of patent right |