CN1556082A - Preparation method of 1,1-difluoro ethane and its production equipment - Google Patents
Preparation method of 1,1-difluoro ethane and its production equipment Download PDFInfo
- Publication number
- CN1556082A CN1556082A CNA2004100156622A CN200410015662A CN1556082A CN 1556082 A CN1556082 A CN 1556082A CN A2004100156622 A CNA2004100156622 A CN A2004100156622A CN 200410015662 A CN200410015662 A CN 200410015662A CN 1556082 A CN1556082 A CN 1556082A
- Authority
- CN
- China
- Prior art keywords
- reaction
- valve
- reaction kettle
- catalyst
- difluoroethane
- 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
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 17
- NPNPZTNLOVBDOC-UHFFFAOYSA-N 1,1-difluoroethane Chemical compound CC(F)F NPNPZTNLOVBDOC-UHFFFAOYSA-N 0.000 title claims description 17
- 238000002360 preparation method Methods 0.000 title claims description 7
- 229940051271 1,1-difluoroethane Drugs 0.000 title description 3
- 238000006243 chemical reaction Methods 0.000 claims abstract description 99
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 claims abstract description 48
- 239000003054 catalyst Substances 0.000 claims abstract description 39
- HSFWRNGVRCDJHI-UHFFFAOYSA-N alpha-acetylene Natural products C#C HSFWRNGVRCDJHI-UHFFFAOYSA-N 0.000 claims abstract description 15
- 125000002534 ethynyl group Chemical group [H]C#C* 0.000 claims abstract description 15
- 239000007788 liquid Substances 0.000 claims description 21
- UQSQSQZYBQSBJZ-UHFFFAOYSA-N fluorosulfonic acid Chemical group OS(F)(=O)=O UQSQSQZYBQSBJZ-UHFFFAOYSA-N 0.000 claims description 10
- 238000007599 discharging Methods 0.000 claims description 6
- 238000000034 method Methods 0.000 claims description 6
- 238000003860 storage Methods 0.000 claims description 4
- 239000002994 raw material Substances 0.000 abstract description 7
- 238000009835 boiling Methods 0.000 description 6
- 239000000463 material Substances 0.000 description 6
- 230000009286 beneficial effect Effects 0.000 description 4
- 238000006555 catalytic reaction Methods 0.000 description 4
- 230000005484 gravity Effects 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- 229910021630 Antimony pentafluoride Inorganic materials 0.000 description 3
- VBVBHWZYQGJZLR-UHFFFAOYSA-I antimony pentafluoride Chemical compound F[Sb](F)(F)(F)F VBVBHWZYQGJZLR-UHFFFAOYSA-I 0.000 description 3
- 239000007791 liquid phase Substances 0.000 description 3
- 230000036632 reaction speed Effects 0.000 description 3
- 230000035484 reaction time Effects 0.000 description 3
- WTEOIRVLGSZEPR-UHFFFAOYSA-N boron trifluoride Chemical compound FB(F)F WTEOIRVLGSZEPR-UHFFFAOYSA-N 0.000 description 2
- 239000006227 byproduct Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 239000003507 refrigerant Substances 0.000 description 2
- 238000005406 washing Methods 0.000 description 2
- 229910015900 BF3 Inorganic materials 0.000 description 1
- KRHYYFGTRYWZRS-UHFFFAOYSA-M Fluoride anion Chemical compound [F-] KRHYYFGTRYWZRS-UHFFFAOYSA-M 0.000 description 1
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 description 1
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 239000012267 brine Substances 0.000 description 1
- 238000004587 chromatography analysis Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000006471 dimerization reaction Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 229910052731 fluorine Inorganic materials 0.000 description 1
- 239000011737 fluorine Substances 0.000 description 1
- 229920002313 fluoropolymer Polymers 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 150000002894 organic compounds Chemical class 0.000 description 1
- 239000012071 phase Substances 0.000 description 1
- 238000006116 polymerization reaction Methods 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- HPALAKNZSZLMCH-UHFFFAOYSA-M sodium;chloride;hydrate Chemical compound O.[Na+].[Cl-] HPALAKNZSZLMCH-UHFFFAOYSA-M 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 238000005829 trimerization reaction Methods 0.000 description 1
- 238000013022 venting Methods 0.000 description 1
- 238000010792 warming Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
A process for preparing 1,1-bifluoroethane features that the initial lever of hydrofluoric acid is 60-70% of reactor's volume, the weight of catalyst is 30-40% of the weight of hydrofluoric acid, the feeding speed of acetylene is 0.08-0.12 kg/h for each kg of hydrofluoric acid, and the reaction temp and presure are 22-32 deg.C and 0.03-0.3 MPa. Its productive equipment is also disclosed, which features small ratio of length to diameter, full reaction, and less consumption of raw material.
Description
Technical Field
The invention relates to a preparation method of 1.1 difluoroethane and production equipment thereof. Is suitable for the refrigerant production industry.
Background
1.1 Difluoroethane (CH)3CHF2) Currently, HFC-152a, the international common name of which is fluorine-containing organic compound, is widely used as a raw material for refrigerants, sprays and fluoroplastics production, and particularly, its Ozone Depletion Potential (ODP) is 0 and Global Warming Potential (GWP) is 0.02, so that it is receiving more and more attention as a substitute for CFC. 1.1 conventional Process for the production of difluoroethane is advantageousUsing the B block as a raw material, and reacting in a catalyst such as: reacting boron trifluoride, fluorosulfonic acid and antimony pentafluoride with hydrofluoric acid to obtain the compound, wherein the reaction formula is as follows:
the process flow is that acetylene after purification and drying treatment is sent into a reaction kettle filled with catalyst (such as fluorosulfonic acid) and hydrofluoric acid, and reacts under certain pressure (0.03-3 mpa) and temperature (20-40 ℃) to generate 1.1 difluoroethane, and after water washing, alkali washing and deacidification, gas-phase materials are compressed into liquid-phase materials, and then the liquid-phase materials are fractionated and purified to obtain the catalyst.
The reaction is semi-continuous, liquid hydrofluoric acid is added into the reactor, and gas acetylene is continuously introduced into the reactor until the conversion rate is lower than 60% (conversion rate in the first reactor during the second reaction), the reaction is stopped, the remainder (usually called residual liquid) in the reactor is discharged, the catalyst and hydrofluoric acid are added again, and the reaction is started again.
In order to increase the conversion rate of the reaction as much as possible and ensure sufficient contact time between acetylene and hydrofluoric acid, the length-diameter ratio (L/D, L is the height of the reactor, and D is the diameter of the reactor) of the reactor is often more than or equal to 4.
During operation, the temperature is controlled by cold-hot brine through a pneumatic valve, the pressure is controlled by the feeding amount of acetylene through the pneumatic valve, and the hydrofluoric acid liquid level in the reactor is intermittently replenished according to the indication of a liquid level meter.
The production process has the following defects: 1) in order to increase the conversion of the reaction as much as possible, the length-to-diameter ratio of the reactor is often greater than 4, and the reactor is of a long and narrow type. The specific gravity of the fluorosulfonic acid and antimony pentafluoride used as catalysts is much larger than that of hydrofluoric acid, the specific gravity of the hydrofluoric acid is 1.15, the specific gravity of the fluorosulfonic acid is 1.74, the specific gravity of the antimony pentafluoride is 2.34, the catalysts are usually sunk at the bottom of a reactor and can only play a role of catalysis in a small range, and the conversion rate of direct reaction of acetylene and the hydrofluoric acid is low (about 30-40%), so that the utilization rate of the catalysts in the production process is low, the reaction period is short, the unit consumption is high, and the discharge amount of residual liquid is large. 2) The reaction of acetylene and hydrofluoric acid is an exothermic reaction under the influence of temperature, the heat released along with the change of the reaction speed is also changed, and the heat released in the early stage of the reaction is large, so that the reaction does not need to be heated, but needs to be cooled; the reaction requires heating at the latter stage, so that temperature control is difficult. If the reaction temperature is lower, the reaction speed is slow, the production capacity of the device is reduced, if the temperature is higher, the catalyst is quick to lose efficacy, high-boiling byproducts are increased, the consumption of raw materials is increased, and the reaction and the high-boiling byproducts are not beneficial to production. 3) The block B is a substance with extremely strong chemical activity and can generate self-polymerization under certain conditions, when the pressure in the reactor is high, the density of acetylene is relatively increased, dimerization, trimerization and corresponding fluoride (high-boiling-point substance) can be possibly generated, the unit consumption is increased, the viscosity of materials in the reactor is increased, and the reaction is unfavorable; if the reaction pressure is too low, the reaction speed is affected, and the productivity of the device is reduced. 4) The liquid level is influenced by the fact that the reaction is continuous, the hydrofluoric acid is supplemented, the second block is continuously added, the product is continuously removed from the top, the liquid level in the reactor is correspondingly reduced, the density of the second block in the liquid phase is increased (other conditions are not changed), and therefore, high-boiling substances are increased, and the production is not good. 5) In the whole reaction, the catalyst is not convenient to be supplemented, the residual liquid is inconvenient to be discharged, the reaction process cannot be adjusted, and the residue in the reactor is discharged from the bottom once when the reaction is finished.
Disclosure of Invention
The technical problem to be solved by the invention is as follows: the preparation method and the production equipment of the 1.1 difluoroethane are provided, the length-diameter ratio of the equipment reactor is small, and the structure is more reasonable; the catalyst can be recycled, is uniformly distributed and fully plays a role in catalysis; partially deactivated or low-efficiency catalyst and high-boiling residual liquid in the reactor can be discharged at any time according to the requirement in the reaction process; replenishing the catalyst in time; the system reaction can be continuously carried out, and the unit consumption of raw materials is reduced; and the system is beneficial to improving and upgrading.
The technical scheme adopted by the invention is as follows: the production equipment for preparing 1.1 difluoroethane is provided with a reaction kettle, the top of which is provided with a feeding pipe, and is characterized in that the reaction kettle is connected with an external circulation system, the system is provided with an external circulation pump, the circulation pump is communicated with the bottom of the reaction kettle through a lower connecting pipe and a valve I, the circulation pump is communicated with the middle part of the reaction kettle through an upper connecting pipe and a valve IV, a liquid discharge pipe and a valve III are connected between the external circulation pump and the valve IV, the lower connecting pipe between the external circulation pump and the valve I is connected with a valve II and a replenishing tank, and the top of the replenishing tank is connected with a valve V and a.
The lower connecting pipe is arranged at a position 100 mm away from the bottom of the reaction kettle.
The upper connecting pipe is arranged at the upper 2/3 position of the reaction kettle.
A preparation method of 1, 1 difluoroethane comprises the following steps:
1) the initial liquid level of hydrofluoric acid in the reaction kettle is 60-70% of the volume of the reaction kettle;
2) the catalyst is fluorosulfonic acid, and the addition amount is 30-40% of the weight of hydrofluoric acid;
3) the feeding speed of acetylene is 0.08-0.12 kg/h for each kg of hydrofluoric acid;
4) the liquid level change in the reaction kettle is less than or equal to 100 mm;
5) when the conversion is lower than 60%, discharging 30-40% by weight of catalyst, and adding an equal amount of new catalyst, which can be repeated for many times;
6) the reaction temperature is 22-32 ℃;
7) the reaction pressure is 0.03-0.3 MPa.
The reaction temperature is preferably 26 to 28 ℃.
The reaction pressure is preferably 0.05 to 0.1 MPa.
The invention has the beneficial effects that: 1) the length-diameter ratio of the reaction kettle can be reduced, because the conversion rate of the reaction of the second block and hydrofluoric acid is lower (30-40%), the meaning of simply amplifying the length-diameter ratio is not large, and the length-diameter ratio can be reduced, and the consumption of equipment materials is reduced; 2) after the external circulation system is started, the catalyst settled at the bottom can be conveyed to the upper surface of the reaction kettle, so that the catalyst is uniformly distributed in the whole reaction kettle and fully plays a role of catalysis; 3) the catalyst and the high-boiling residual liquid which are ineffective or ineffective in the reaction kettle can be discharged at propertime; 4) the catalyst in the catalyst replenishing tank can be added into the reaction kettle at a proper time; 5) the system reaction is continuously carried out, so that the unit consumption of raw materials and catalysts is effectively reduced; 6) the device is beneficial to upgrading and improving equipment, manual control is improved into microcomputer control, parameters such as reaction temperature, pressure, liquid level and the like are measured by a measuring instrument and converted into electronic signals, the electronic signals are transmitted to an electric control instrument, and adjustment is carried out according to instructions of a computer, so that temperature fluctuation is controlled to be about 2 ℃, pressure is controlled to be about 0.002 MPa, and liquid level fluctuation is within 50 mm, and the reaction is effectively ensured to be carried out under the optimal condition.
Drawings
FIG. 1 is a system block diagram of the present invention.
Detailed Description
FIG. 1 shows a system structure diagram of the present invention, which comprises a reaction kettle 1, a feed pipe 2, a discharge pipe 3, a replenishing tank 3, an external circulation pump 4, a lower connection pipe 5, an upper connection pipe 6, a catalyst storage tank 7, a liquid discharge pipe 8, a valve I (11), a valve II (12), a valve III (13), a valve IV (14) and a valve V (15).
The diameter of a reaction kettle 1 is 600mm, the height of the reaction kettle is 2000mm, the top of the reaction kettle is provided with a feeding pipe 2 and a discharging pipe 3, one side of the reaction kettle is provided with an external circulating system, the system is provided with an external circulating pump 4, the circulating pump is communicated with the bottom of the reaction kettle through a lower connecting pipe 5 and a valve I (11), and the lower connecting pipe is connected at a position 100 mm away from the bottom of the reaction kettle; the circulating pump is communicated with the middle part of the reaction kettle through an upper connecting pipe 6 and a valve IV (14), and the upper connecting pipe is connected with the upper 2/3 part of the reaction kettle. A liquid discharge pipe 8 and a valve III (13) are connected between the external circulation pump 4 and the valve IV (14). A valve II (12) and a replenishing tank 3 are connected to a lower connecting pipe 5 between an external circulating pump 4 and a valve I (11), and the top of the replenishing tank is connected with a valve V (15) and a catalyst storage tank (7).
The steps of starting the external circulation system are as follows:
1) the external circulation pump 4 is started, the valves I (11) and IV (14) are opened, and the catalyst settled at the bottom can be sent to the upper part of the reaction kettle, so that the catalyst is uniformly distributed in the whole reaction kettle and fully plays a role of catalysis.
2) Valves II (12) and IV (14) are closed and valves I (11) and III (13) are opened to allow the venting of partially spent or inefficient catalyst and high boiling raffinate from the reactor.
3) The valves I (11), III (13), II (12) and IV (14) are closed, the valve V (15) is opened, the catalyst in the catalyst storage tank 7 is put into the replenishing tank 3, the valve V (15) is closed, the valve II (12) and the valve IV (14) are opened, and the catalyst in the catalyst replenishing tank 3 can be added into the reaction kettle 1.
4) By adopting the switching operation of the steps 2 and 3, the system reaction can be continuously carried out, and the unit consumption of hydrofluoric acid and fluorosulfonic acid is reduced.
Example one, catalyst life comparison:
a reaction device: the diameter of the reaction kettle is 600mm, the height is 2000mm, and the external circulation system is started in the embodiment.
Reaction conditions are as follows: the temperature is 22-32 ℃, the pressure is 0.03-0.3mpa in the example, 0.05mpa (both manual controls) is selected in the example, the initial liquid level of hydrofluoric acid in the feeding amount is 60-70% of the volume of the reaction kettle, 60% is selected in the example, the feeding speed of acetylene is 0.08-0.12 kg/h of acetylene per kg of hydrofluoric acid, the volume is converted into 10M of acetylene in the example3The reaction should be continued for a period of time/hour, and stopped when the conversion (chromatographic analysis) has dropped to 60%, as shown in Table 1:
TABLE 1
| Reaction temperature (. degree.C.) | Pressure (mpa) | Fluorosulfonic acid dosage (Kg) | Reaction time (h) | |
| Original device | 28 | 0.05 | 150 | 196 |
| The invention | 28 | 0.05 | 150 | 372 |
Example two, comparison of material consumption per unit:
a reaction device: the same as the first embodiment;
reaction conditions are as follows: the same as the first embodiment;
it was concluded that table 2 shows:
TABLE 2
| Reaction temperature (. degree.C.) | Pressure (mpa) | Fluorosulfonic acid dosage (Kg) | HF unit consumption | Unit consumption of acetylene | |
| Original device | 28 | 0.05 | 150 | 0.77 | 1.78 |
| The invention | 28 | 0.05 | 150 | 0.71 | 1.65 |
Example three, catalyst replenishment comparative experiment:
a reaction device: the same as the first embodiment;
reaction conditions are as follows: the same as the first embodiment;
the first set of reactions was conducted without discharging raffinate and without adding additional catalyst, and the second set of reactions was conducted with discharging 1/3 raffinate (indicated by a level gauge) in the reactor at a conversion of 60% and with adding an equal amount of catalyst, the results of which are shown in Table 3:
TABLE 3
| Reaction temperature (. degree.C.) | Pressure (mpa) | Fluorosulfonic acid dosage (Kg) | Acetylene charge (M)3/h) | Reaction time | |
| First group | 28 | 0.05 | 150 | 10 | 363 |
| Second group | 28 | 0.05 | 150 | 10 | 358 |
| Is supplemented with 50 | 512 |
From the above experiments, it can be obtained that the invention has the advantages of reducing the raw material unit consumption, prolonging the reaction time and improving the reaction efficiency compared with the existing device and process.
Claims (6)
1. The utility model provides a prepare production facility of 1.1 difluoroethane, has reation kettle (1), its top has inlet pipe (2) and discharging pipe (3), its characterized in that: the reaction kettle (1) is connected with an external circulation system, the system is provided with an external circulation pump (4), the circulation pump is communicated with the bottom of the reaction kettle through a lower connecting pipe (5) and a valve I (11), the circulation pump is communicated with the middle of the reaction kettle through an upper connecting pipe (6) and a valve IV (14), a liquid discharge pipe (8) and a valve III (13) are connected between the external circulation pump (4) and the valve IV (14), a lower connecting pipe (5) between the external circulation pump (4) and the valve I (11) is connected with a valve II (12) and a replenishing tank (3), and the top of the replenishing tank is connected with a valve V (15) and a catalyst storage tank (7).
2. The production apparatus for producing 1.1 difluoroethane as claimed in claim 1, wherein: the lower connecting pipe (5) is arranged at a position 100 mm away from the bottom of the reaction kettle (1).
3. The production apparatus for producing 1.1 difluoroethane as claimed in claim 1, wherein: the upper connecting pipe (6) is arranged at the upper 2/3 position of the reaction kettle (1).
4. A preparation method of 1.1 difluoroethane is characterized in that:
1) the initial liquid level of hydrofluoric acid in the reaction kettle is 60-70% of the volume of the reaction kettle;
2) the catalyst is fluorosulfonic acid, and the addition amount is 30-40% of the weight of hydrofluoric acid;
3) the feeding speed of acetylene is 0.08-0.12 kg/h for each kg of hydrofluoric acid;
4) the liquid level change in the reaction kettle is less than or equal to 100 mm;
5) when the conversion is lower than 60%, discharging 30-40% by weight of catalyst, and adding an equal amount of new catalyst, which can be repeated for many times;
6) the reaction temperature is 22-32 ℃;
7) the reaction pressure is 0.03-0.3 MPa.
5. The process for the preparation of 1.1 difluoroethane as claimed in claim 4, wherein: the reaction temperature is preferably 26 to 28 ℃.
6. The process for the preparation of 1.1 difluoroethane as claimed in claim 4, wherein: the reaction pressure is preferably 0.05 to 0.1 MPa.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200410015662 CN1273425C (en) | 2004-01-02 | 2004-01-02 | Preparation method of 1,1-difluoro ethane and its production equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200410015662 CN1273425C (en) | 2004-01-02 | 2004-01-02 | Preparation method of 1,1-difluoro ethane and its production equipment |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1556082A true CN1556082A (en) | 2004-12-22 |
| CN1273425C CN1273425C (en) | 2006-09-06 |
Family
ID=34351458
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200410015662 Expired - Lifetime CN1273425C (en) | 2004-01-02 | 2004-01-02 | Preparation method of 1,1-difluoro ethane and its production equipment |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1273425C (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110028377A (en) * | 2019-02-25 | 2019-07-19 | 内蒙古永和氟化工有限公司 | A kind of preparation process of 1,1- Difluoroethane |
-
2004
- 2004-01-02 CN CN 200410015662 patent/CN1273425C/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110028377A (en) * | 2019-02-25 | 2019-07-19 | 内蒙古永和氟化工有限公司 | A kind of preparation process of 1,1- Difluoroethane |
| CN110028377B (en) * | 2019-02-25 | 2023-07-14 | 内蒙古永和氟化工有限公司 | Preparation process of 1,1-difluoroethane |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1273425C (en) | 2006-09-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1235894C (en) | Process for epoxidation of olefins | |
| CN103803584B (en) | Ammonium bifluoride preparation method | |
| CN112645793B (en) | Process system and method for producing trans-1-chloro-3, 3-trifluoropropene | |
| CN104945221A (en) | Method for co-production of 2,3,3,3-tetrafluoropropene and 1,3,3,3-tetrafluoropropene | |
| CN111440047B (en) | Preparation method of 1,1,1,3, 3-pentachloropropane | |
| CN103570760B (en) | Hydroxy ethylene diphosphonic acid production unit and method thereof | |
| CN1556082A (en) | Preparation method of 1,1-difluoro ethane and its production equipment | |
| JP4388753B2 (en) | Method for producing acetic acid using heterogeneous catalyst | |
| KR20120024310A (en) | Preparation method of propylene glycol monomethyl ether acetate | |
| CN104692998B (en) | The preparation method of bis- fluoro- 2- chloroethanes of 1,1- | |
| CN103420777B (en) | Method for continuously synthesizing 1, 5, 9-cyclododecatriene | |
| CN102086214B (en) | Method for producing gamma-chloropropyl triethoxysilane | |
| CN209885775U (en) | Device for preparing 1,1,1, 3-tetrachloropropane | |
| CN102701920A (en) | Method for purifying vinyl isobutyl ether | |
| CN1336359A (en) | Three-phase phase-transfer catalytic synthesis process of 9,9-dimethoxyl methyl) fluorene | |
| CN111659322A (en) | Device and process for preparing 1,1,1, 3-tetrachloropropane | |
| CN105481625B (en) | A kind of production method of ENB | |
| CN1331066A (en) | Method for preparing perfluoroethyl | |
| CN1245369C (en) | Process for the preparation of 2-ethylhexanal | |
| CN115417744B (en) | Method for preparing 1-chloro-1, 1-difluoroethane | |
| JP4048549B1 (en) | Method for producing tertiary butanol | |
| CN1158252C (en) | Process for preparing biurea | |
| CN111054402B (en) | TiOF 2 Catalyst, preparation method and application thereof | |
| CN113511954B (en) | Continuous flow preparation method of 1,2, 3-trichloropropane | |
| EP0213215B1 (en) | Chlorosilane disproportionation catalyst and method for producing a silane compound by means of the catalyst |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CX01 | Expiry of patent term |
Granted publication date: 20060906 |
|
| CX01 | Expiry of patent term |