HFO-1234ze, HFO-1225zc and HFO-1234yf compositions and processes for producing and using the compositions
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Solution Overview
Problem
Current methods for producing HFO-1234ze and HFO-1234yf refrigerants require additional purification or separation steps to remove excess Z-isomer, increasing costs and complexity, while there is a need for a process that minimizes or eliminates these steps and achieves a composition with HFO-1225zc and HFO-1234yf in specific mole percentages.
Innovation Solution
A method involving contacting a mixture of 1,1,1,3,3-pentafluoropropane and Z-1,3,3-tetrafluoropropene in the gas phase with a catalyst like fluorinated Cr2O3 or Cr/Ni on alumina, in the presence of an oxygen-containing gas, to produce a mixture comprising Z-1,3,3-tetrafluoropropene, E-1,3,3-tetrafluoropropene, 1,1,3,3-pentafluoropropene, and 2,3,3-tetrafluoropropene without the need for purification or separation of excess 2,3,3-tetrafluoropropene.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If catalytic dehydrofluorination of HFC-245fa is performed to produce HFO-1234ze, then HFO-1234ze is obtained, but a mixture of E-isomer and Z-isomer is produced requiring additional separation steps
Solution Approach 1:
The patent changes the reaction parameters by introducing oxygen-containing gas and using specific catalysts (fluorinated Cr2O3 or Cr/Ni on alumina) to modify the dehydrofluorination process. This causes the Z-isomer to decompose selectively while the E-isomer remains stable, achieving isomer separation through chemical transformation rather than physical separation methods
Solution Approach 2:
The patent extracts or removes the problematic Z-isomer from the product mixture by causing its selective decomposition in the presence of oxygen. The Z-isomer is converted to decomposition products (CO2, H2O, HF) while the desired E-isomer is preserved, effectively extracting the harmful component from the mixture
2Manufacturing precision
If additional purification steps are added to remove excess Z-isomer, then isomer purity is improved, but manufacturing cost and process complexity increase
Solution Approach 1:
The patent converts the harmful Z-isomer, which normally requires costly separation, into a beneficial by decomposing it selectively in the presence of oxygen. The Z-isomer acts as a reactant that can be eliminated through controlled oxidation, transforming a manufacturing burden into a manageable chemical reaction
Solution Approach 2:
By changing the reaction atmosphere to include oxygen and adjusting catalyst selection, the patent modifies the dehydrofluorination process to inherently produce higher E-isomer purity. This parameter change eliminates the need for additional purification equipment and reduces manufacturing costs
3Productivity
If HFO-1225zc and HFO-1234yf are produced as byproducts, then complete conversion of HFC-245fa is achieved, but purification steps are required to meet composition specifications
Solution Approach 1:
The patent adjusts reaction parameters (oxygen presence, temperature, catalyst type) to control the dehydrofluorination process such that HFO-1225zc and HFO-1234yf are produced in controlled amounts that naturally meet the specification of greater than zero and less than about 1 mole percent each, eliminating the need for additional purification steps
Solution Approach 2:
The patent maintains continuous dehydrofluorination reaction conditions that simultaneously achieve high conversion of HFC-245fa and produce the desired composition range of byproducts. The process continuously generates HFO-1234ze(E), HFO-1225zc, and HFO-1234yf in the correct proportions without interruption or additional processing steps
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 process effectively produces a composition with HFO-1234ze, HFO-1225zc, and HFO-1234yf, reducing the need for additional purification steps and achieving the desired mole percentages, making it suitable for use as a refrigerant with low ozone depletion and global warming potential.
Implementation Method 1
contacting a mixture of 1,1,1,3,3-pentafluoropropane and Z-1,3,3-tetrafluoropropene in the gas phase with a catalyst like fluorinated Cr2O3 or Cr/Ni on alumina
Implementation Method 2
in the presence of an oxygen-containing gas
Data Source
AI summary
A fluoropropene composition comprising Z-1,3,3,3-tetrafluoropropene, E-1,3,3,3-tetrafluoropropene, 1,1,3,3,3-pentafluoropropene, 2,3,3,3-tetrafluoropropene, and optionally 1,1,1,3,3-pentafluoropropane wherein the 2,3,3,3-tetrafluoropropene being present in an amount of 0.00001 to 1.0%. A method of producing the fluoropropene, methods for using the fluoropropene and the composition formed are also disclosed.