Olefin HF-SbF5 Composition for High-Conversion Hydrofluorination
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Solution Overview
Problem
Existing methods for producing fluorinated hydrocarbons like HFO-1234yf face challenges such as incomplete conversion of 1233xf to 244bb due to equilibrium limitations and the presence of 1233xf in the starting material, leading to reduced yield and formation of undesirable by-products like trifluoropropyne and oligomers, with separation of isomers being difficult and costly.
Innovation Solution
A method involving the hydrofluorination of fluoroolefins with HF in the liquid phase using SbF5 catalyst at temperatures ranging from -30°C to 65°C, allowing for high conversion of 1233xf to 244bb with improved selectivity and yield, minimizing the need for costly purification steps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fluorinated SbCl5 catalyst is used for hydrofluorination at temperatures above 70°C, then the catalyst remains active (does not freeze), but the conversion of 1233xf to 244bb is incomplete due to equilibrium limitations
Solution Approach 1:
The patent changes the temperature parameter from above 70°C to -30°C to 65°C, and changes the catalyst from fluorinated SbCl5 to SbF5. This parameter change resolves the contradiction by enabling complete conversion while maintaining catalyst activity through the lower temperature operation and different catalyst system.
Solution Approach 2:
The patent uses SbF5 as an alternative to fluorinated SbCl5, creating a similar functional catalyst system (antimony fluoride instead of antimony chloride) that achieves the same catalytic activity at lower temperatures, thereby resolving the equilibrium limitation issue.
2Speed
If higher temperatures are used for hydrofluorination to improve conversion, then reaction rate increases, but equilibrium limitations prevent complete conversion of 1233xf to 244bb
Solution Approach 1:
The patent changes the temperature parameter to a lower range (-30°C to 65°C) combined with using SbF5 catalyst, which fundamentally alters the equilibrium position to favor complete conversion of 1233xf to 244bb, resolving the contradiction between reaction rate and conversion completeness.
3Adaptability or versatility
If 1233xf is present in the starting material, then the reaction can proceed, but the presence of 1233xf leads to reduced conversion of HCFC-244bb to HFO-1234yf and formation of undesirable by-products
Solution Approach 1:
The patent converts the harmful effect of 1233xf presence into a benefit by using SbF5 catalyst at lower temperatures to completely convert 1233xf to 244bb before it can form undesirable by-products. The same starting material that previously caused problems is now completely converted to the desired intermediate.
Solution Approach 2:
The patent ensures continuous conversion of 1233xf to 244bb through optimized reaction conditions with SbF5 catalyst, preventing the formation of by-products like trifluoropropyne and oligomers by maintaining complete conversion throughout the process.
4Manufacturing precision
If separation of 1233xf and 244bb is performed to purify the product, then product purity increases, but the separation is difficult and expensive due to similar boiling points
Solution Approach 1:
The patent converts the difficulty of separation into a benefit by using SbF5 catalyst to achieve complete conversion of 1233xf to 244bb, eliminating the need for costly separation processes. The starting material that would normally require separation is now completely converted to the desired product.
Solution Approach 2:
The patent extracts the need for separation by achieving complete conversion through optimized catalytic conditions, thereby eliminating the harmful factor of mixed products and the associated separation costs and complexities.
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 process achieves high conversion rates of 90% to 99% of 1233xf to 244bb, significantly increasing the yield of desired hydrofluoroalkanes with reduced energy consumption and avoiding the formation of undesirable by-products, thus enhancing the efficiency and cost-effectiveness of the production process.
Implementation Method 1
reacting the fluoroolefin with HF in the liquid-phase, in the presence of SbF5
Data Source
AI summary
A composition includes a mixture including HF, SbF5, and olefin selected from 1-chloro-3,3,3-trifluoropropene, a chlorotetrafluoropropene, 2,3,3,3-tetrafluoropropene, 1,3,3,3-tetrafluoropropene, 3,3,3-trifluoropropene, and RCX═CYZ. X, Y, and Z are independently the same or different and are H, F, Cl, Br, or C1-C6 alkyl which is partially or fully substituted with chloro or fluoro or bromo. At least one of X, Y, and Z is H, Cl, Br, or C1-C6 alkyl which is partially or fully substituted with chloro or fluoro or bromo. R is a C2-C6 alkyl which is partially or fully substituted with chloro or fluoro or bromo. When R is C2 alkyl which is fully substituted with fluoro, X, Y, and Z are not all H. The SbF5 is present in an amount in the range of up to about 30%, by weight of the mixture.