1,2,3,4-Tetrachlorohexafluorobutane Production via HF Solvent Fluorination
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Solution Overview
Problem
Current processes for producing 1,2,3,4-tetrachlorohexafluorobutane face challenges such as low yield due to side reactions, excessive fluorination, and the need for high reaction temperatures, which hinder industrial efficiency and product purity.
Innovation Solution
Reacting 1,2,3,4-tetrachlorobutane with fluorine in the presence of a solvent containing hydrogen fluoride, controlling reaction conditions like temperature and pressure, and using distillation and alkaline treatment to separate and refine the product.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If 1,2,3,4-tetrachlorobutane is reacted with fluorine in a liquid phase using conventional solvents, then the reaction can proceed, but side reactions occur and yield decreases due to C—C cleavage and excessive fluorination
Solution Approach 1:
The invention changes the chemical composition parameter of the solvent system by using hydrogen fluoride-containing solvents (such as HF-BF3 complex, HF-SbF5 complex, or mixtures with perfluorinated solvents) instead of conventional solvents. This parameter change modifies the reaction environment to suppress C—C bond cleavage and excessive fluorination, thereby reducing side reactions and improving yield.
Solution Approach 2:
The invention introduces hydrogen fluoride as an intermediary substance that mediates the fluorination reaction. Hydrogen fluoride acts as a catalyst and reaction medium that facilitates the controlled introduction of fluorine atoms while preventing uncontrolled C—C bond breaking and excessive fluorination, thus improving selectivity and yield.
2Productivity
If high reaction temperature is used to maintain liquid phase reaction, then the reaction proceeds, but side reactions increase and product purity decreases
Solution Approach 1:
The invention changes the temperature parameter by conducting the reaction at lower temperatures (−50°C to +50°C, preferably −30°C to +20°C) compared to conventional high-temperature processes. This temperature reduction suppresses thermal side reactions and C—C cleavage while maintaining acceptable reaction rates through the catalytic effect of hydrogen fluoride-containing solvents.
3Ease of manufacture
If conventional solvents are used for fluorination reaction, then the reaction can proceed, but solvent separation and recovery processes are required, increasing process complexity
Solution Approach 1:
The invention applies the self-service principle by using 1,2,3,4-tetrachlorohexafluorobutane (the product itself) as the solvent for the fluorination reaction. This eliminates the need for separate solvent removal and recovery systems, as the product serves its own function as the reaction medium, thereby simplifying the overall process and reducing equipment complexity.
4Device complexity
If product is used as solvent to avoid separation, then process simplification is achieved, but reverse reaction becomes more likely due to Gibbs free energy considerations
Solution Approach 1:
The invention introduces hydrogen fluoride as a chemical intermediary that shifts the reaction equilibrium toward the product side. By using hydrogen fluoride-containing solvents, the reaction environment is modified to favor forward fluorination, suppressing the reverse reaction despite the product serving as the solvent medium.
Solution Approach 2:
The invention changes the chemical composition parameter of the reaction medium by incorporating hydrogen fluoride, which alters the thermodynamic parameters of the system. This composition change affects the Gibbs free energy landscape, making the forward reaction more favorable and suppressing reverse reactions even when the product acts as the solvent.
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
This method enhances the yield and purity of 1,2,3,4-tetrachlorohexafluorobutane, reduces side reactions, and allows for the economic and efficient production of the compound.
Implementation Method 1
reacting 1,2,3,4-tetrachlorobutane with fluorine in the presence of a solvent containing hydrogen fluoride
Implementation Method 2
a reaction liquid containing 1,2,3,4-tetrachlorohexafluorobutane produced by reacting 1,2,3,4-tetrachlorobutane with fluorine in the presence of the solvent containing hydrogen fluoride is introduced into a distillation column to separate at least a part of 1,2,3,4-tetrachlorohexafluorobutane from the reaction liquid
Implementation Method 3
the separated 1,2,3,4-tetrachlorohexafluorobutane is brought into contact with an alkaline substance and/or water
Data Source
AI summary
The production process for 1,2,3,4-tetrachlorohexafluorobutane of the present invention is characterized in that 1,2,3,4-tetrachlorobutane is reacted with fluorine in the presence of a solvent containing hydrogen fluoride. The 1,2,3,4-tetrachlorobutane may be obtained by chlorination of 3,4-dichlorobutene-1. Further, the present invention provides as well a process of refining 1,2,3,4-tetrachlorohexafluorobutane obtained in the manner described above. According to the present invention, 1,2,3,4-tetrachlorohexafluorobutane which is useful, for example, as a synthetic raw material for hexafluoro-1,3-butadiene used as an etching gas for semiconductors can industrially efficiently be produced by using 1,2,3,4-tetrachlorobutane which is a by-product of chloroprene and which has so far been disposed.