A kind of preparation method and fluorination catalyst of 1,1-difluoroethane

A technology based on fluorination catalyst and difluoroethane, applied in 1 field

Active Publication Date: 2011-12-28
ZHEJIANG QUHUA FLUOR CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This conventional method is undesirable because it produces a large amount of tar, affects the yield of the product, and is difficult to dispose of.

Method used

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  • A kind of preparation method and fluorination catalyst of 1,1-difluoroethane
  • A kind of preparation method and fluorination catalyst of 1,1-difluoroethane

Examples

Experimental program
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Effect test

Embodiment 1

[0038] After the anhydrous hydrofluoric acid and acetylene are vaporized, they are mixed into a 180ml carbon steel fixed-bed reactor capable of receiving materials, and the fluorination reaction is carried out under the action of a chromium-based catalyst, and the material ratio of anhydrous hydrofluoric acid and acetylene is controlled 8 : 1, 230°C of reaction temperature, pressure 1.0Mpa, (under standard conditions) reactor space velocity 800h -1 , sampling and analyzing the outlet material of the reactor, the conversion rate of acetylene is 78.55%, and the selectivity of HFC-152a is 95.40%.

preparation Embodiment 1

[0052] 0.5gIn(NO 3 ) 3 9H 2 O, 4g CoCl 2 ·6H 2 O and 50g Cr(NO 3 ) 3 9H 2 O was dissolved in 800g of pure water to obtain an aqueous solution containing indium, cobalt and chromium, and ammonia water was added to the solution for precipitation reaction, so that the pH value of the reaction solution was in the range of 6.5 to 10, filtered, fully washed with distilled water, and heated at 110°C Dry for 12 hours. Grind the resulting solid, mix it with graphite, press it into tablets with a tablet press, put it into a roasting furnace, and 2 Calcined at 400° C. for 4 hours in air flow to obtain a catalyst precursor. The resulting precursor was loaded into the reaction tube, and the 2 The catalyst was activated at 350°C in a diluted AHF stream, and its physical properties are listed in Table 4.

[0053] Table 4 Physical properties of fluorination catalysts

[0054] catalyst 01 02 Bulk density (g / ml) 0.88 0.90 Specific surface area (m 2 g ...

preparation Embodiment 2

[0057] Cr(NO 3 ) 3 9H 2 The O solution was mixed with ammonia water under sufficient stirring to obtain a chromium hydroxide slurry, which was filtered, the filter cake was fully washed with distilled water, and then dried at 110° C. for 12 hours. Grind the resulting solid, and slowly drop In(NO 3 ) 3 ·nH 2 O and CoCl 2 ·6H 2 Aqueous solution of O. The powder was further dried at 110°C for 12 hours, then mixed with graphite and subsequently granulated with a granulator. Then, molding, calcining and fluorination were performed in the same manner as in Catalyst Preparation Example 1. The physical properties of the catalyst are shown in Table 5.

[0058] Table 5 Physical properties of fluorination catalysts

[0059] catalyst 03 04 Bulk density (g / ml) 0.91 0.92 Specific surface area (m 2 g -1 ) 112.8 115.6 Pore ​​volume (ml·g -1 ) 0.35 0.34

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PUM

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Abstract

The invention discloses a preparation method of 1,1-difluoroethane and a fluorination catalyst used in the method, which is characterized in that under the action of the chromium-based fluorination catalyst described in the invention, acetylene and anhydrous Hydrofluoric acid is vaporized and mixed for gas-phase fluorination reaction to generate 1,1-difluoroethane HFC-152a (C 2H 4F 2 ), the reaction temperature is 140℃~380℃, the pressure is 0.3~1.8MPa, and the reactor is The space velocity is 300h -1 ~ 2200h -1 , the proportion of anhydrous hydrofluoric acid and acetylene in the reaction material is 4:1 ~ 30:1, the conversion rate of acetylene at the reactor outlet reaches more than 75%, and the selectivity of HFC-152a reaches more than 90%.

Description

technical field [0001] The present invention relates to a process for the preparation of hydrofluorocarbons (HFCs). Specifically, 1,1-difluoroethane (CH 4 CF 2 ) preparation method. Background technique [0002] HFC-152a, the molecular structure is CH 3 -CHF 2 , the chemical name is 1,1-difluoroethane, the English name is: 1,1-bifluoroethane, the molecular weight is 66, the boiling point is -24.7°C, the ozone-depleting potential value ODP=0; the global warming coefficient value GWP=0.03, which is a An excellent ODS (ozone depleting substances) substitute. Because the physical and chemical properties and thermodynamic properties of HFC-152a are very similar to CFC-12, it is the preferred substitute of CFC-12. The mixed refrigerant HFC-152a / HCFC-22 is one of the main substances used in recent years to replace CFC-12, which has a destructive effect on the atmospheric ozone layer. In my country, as an environmentally friendly and energy-saving working medium, it is widely...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C19/045C07C17/08B01J27/132
Inventor 周黎旸陈科峰张学良严孝忠苏利红柴龙华
Owner ZHEJIANG QUHUA FLUOR CHEM
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