Chlorine-Containing Fluorocarbon Synthesis via Catalyst-Free HF
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Solution Overview
Problem
Current methods for preparing chlorine-containing propane and propene compounds with 1 or 2 fluorine atoms face challenges such as low yield, difficult handling of starting materials, and inefficient waste treatment, as well as difficulties in achieving monofluorination or difluorination due to excessive trifluorination during fluorination processes.
Innovation Solution
A process involving the contact of chlorine-containing compounds like 1,1,1,2,3-pentachloropropane, 1,1,2,3-tetrachloropropene, and 2,3,3-tetrachloropropene with anhydrous hydrogen fluoride in the absence of a catalyst, either in a gas or liquid phase, at specific temperature ranges to produce chlorine-containing fluorocarbon compounds with high selectivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If fluorination is conducted using SbF3 and SbCl5 as fluorinating agents, then fluorinated products can be obtained, but the yield is low (HCFC-241db: 18%, HCFC-242dc: 28%) and waste treatment is problematic
Solution Approach 1:
The patent changes the fluorinating agent from SbF3/SbCl5 to HF (hydrogen fluoride), fundamentally altering the chemical parameters of the reaction system. This substitution eliminates the need for waste treatment associated with antimony-based agents while achieving high yields (HCFC-241db: 94%, HCFC-242dc: 96%), thereby resolving both the productivity and harmful factors contradictions
Solution Approach 2:
The patent employs HF as a disposable fluorinating agent that can be easily handled and does not require complex waste treatment infrastructure. The simplicity of HF disposal compared to antimony-containing waste streams resolves the waste treatment issue while maintaining high productivity
2Manufacturing precision
If fluorination is conducted in gas phase using chromium-based catalyst, then fluorinated products can be obtained, but fluorination advances too easily to result in trifluorinated product and it is extremely difficult to obtain monofluorinated or difluorinated product
Solution Approach 1:
The patent changes the reaction phase from gas phase to liquid phase, and replaces chromium-based catalyst with HF as fluorinating agent. This parameter change provides superior control over fluorination extent, enabling high selectivity for monofluorinated (94%) and difluorinated (96%) products while preventing over-fluorination to trifluorinated compounds
Solution Approach 2:
The patent uses HF as an intermediary fluorinating agent that provides controlled fluorine transfer to the substrate. This intermediary approach allows precise control over the number of fluorine atoms incorporated, achieving high manufacturing precision for monofluorinated and difluorinated products
3Manufacturing precision
If fluorination is conducted using halogenated antimony catalyst in liquid phase, then fluorinated products can be obtained, but fluorination advances too easily and it is extremely difficult to obtain monofluorinated or difluorinated product
Solution Approach 1:
The patent changes the catalyst system from halogenated antimony to HF, fundamentally altering the reaction mechanism. This change provides excellent selectivity for monofluorinated and difluorinated products while simplifying the device complexity by eliminating the need for specialized catalyst handling and disposal systems
Solution Approach 2:
The patent employs HF as a simple, disposable fluorinating agent that does not require complex catalyst recovery or disposal infrastructure. This approach reduces device complexity while maintaining high selectivity for the desired fluorinated products
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 achieves high yield and selectivity for chlorine-containing fluoropropane and fluoropropene compounds, overcoming the limitations of existing processes by allowing for efficient production on an industrial scale with improved waste management and reduced reaction complexity.
Implementation Method 1
contacting at least one chlorine-containing compound selected from the group consisting of 1,1,1,2,3-pentachloropropane, 1,1,2,3-tetrachloropropene, and 2,3,3-tetrachloropropene with hydrogen fluoride in the absence of a catalyst
Data Source
AI summary
The present invention provides a process for preparing at least one chlorine-containing fluorocarbon compound selected from the group consisting of chlorine-containing fluoropropane compounds represented by Formula (1): CFnCl3-nCHClCH2Cl, wherein n is 1 or 2, and chlorine-containing fluoropropene compounds represented by Formula (2): CFnCl3-nCCl═CH2, wherein n is 1 or 2, wherein the process includes the step of contacting at least one chlorine-containing compound selected from the group consisting of 1,1,1,2,3-pentachloropropane, 1,1,2,3-tetrachloropropene, and 2,3,3,3-tetrachloropropene with hydrogen fluoride in the absence of a catalyst while heating. According to the present invention, the chlorine-containing propane and propene compounds having 1 or 2 fluorine atoms can be prepared by an industrially applicable, simple and effective process.