Fluorochromium Oxide Catalyst Selectivity in Dehydrohalogenation
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Solution Overview
Problem
Conventional methods for producing fluorine-containing olefins through dehydrohalogenation reactions generate significant by-products with strong heat-trapping potential, which complicates global warming concerns and increases production costs due to low boiling points and reduced yield.
Innovation Solution
Employing a highly-fluorinated fluorochromium oxide catalyst with a fluorine content of at least 30% by weight in the dehydrohalogenation reaction from fluorine-containing halogenated propane to reduce by-product generation and enhance the selectivity of fluorine-containing olefins.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional dehydrohalogenation reaction is used to produce fluorine-containing olefin, then fluorine-containing olefin is generated, but a large amount of by-products are generated
Solution Approach 1:
The invention changes the chemical composition parameter of the catalyst by using fluorinated chromium oxide with specific fluorine content (20-40 wt%) instead of conventional chromium oxide catalysts. This parameter change in catalyst composition selectively promotes the dehydrohalogenation reaction while suppressing side reactions that generate by-products such as HFC-23, HFC-143a, and HFC-134, thereby resolving the contradiction between productivity and substance loss.
2Manufacturing precision
If by-products are generated in the reaction, then yield decreases, but separation and removal of by-products is difficult
Solution Approach 1:
The invention applies preliminary anti-action by using the fluorinated chromium oxide catalyst to prevent by-product formation at the source during the dehydrohalogenation reaction. By selectively catalyzing the desired reaction pathway and suppressing side reactions beforehand, the method avoids generating by-products that would require complex separation processes, thus maintaining high yield without increasing device complexity.
3Loss of substance
If by-products with low boiling points are generated, then they can be removed by distillation, but HFC-134 cannot be readily removed due to similar boiling point to target substance
Solution Approach 1:
The invention changes the reaction selectivity parameter through the use of fluorinated chromium oxide catalyst, which preferentially catalyzes the formation of the desired fluorine-containing olefin while minimizing the formation of by-products with similar boiling points like HFC-134. This parameter change in catalyst composition and selectivity eliminates the need for complex separation processes, making by-product removal easier.
4Productivity
If conventional catalyst is used for dehydrohalogenation reaction, then reaction proceeds, but selectivity of fluorine-containing olefin is low
Solution Approach 1:
The invention changes the compositional parameter of the catalyst by incorporating fluorine into chromium oxide to create fluorinated chromium oxide with specific fluorine content (20-40 wt%). This parameter change enhances the catalyst's selectivity for the dehydrohalogenation reaction, preferentially producing fluorine-containing olefin while suppressing side reactions, thus resolving the contradiction between productivity and manufacturing precision.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The use of a highly-fluorinated fluorochromium oxide catalyst effectively minimizes by-products and increases the selectivity of fluorine-containing olefins, addressing global warming concerns and reducing production costs.
Implementation Method 1
fluorochromium oxide having a fluorine content not less than 30% by weight is used as a catalyst in the reaction step
Data Source
AI summary
The present invention aims to reduce an amount of by-products generated in a reaction step for obtaining fluorine-containing olefin, and thereby to obtain fluorine-containing olefin as a target substance with a higher selectivity than that in the conventional method.In a reaction step for generating fluorine-containing olefin by a dehydrohalogenation reaction from fluorine-containing halogenated propane expressed by a general formula CF3CH(2-n)XnCH(3-m)Xm (wherein n=0, 1 or 2; m=1, 2 or 3; and n+m≦3; and X is selected from F, Cl and Br, independently), fluorochromium oxide having a fluorine content not less than 30% by weight is used as a catalyst.