Hydrofluorocarbon Dehydration by Condensation and Water Freezing
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Solution Overview
Problem
The existing dehydration processes for hydrofluorocarbons or hydrochlorofluorocarbons, such as 1,3,3-tetrafluoropropene, require large-scale equipment and are inefficient in removing water vapor, leading to difficulties in distillation and purification due to the formation of azeotropic mixtures and the need for zeolite-packed columns.
Innovation Solution
A dehydration process involving cooling the hydrofluorocarbon or hydrochlorofluorocarbon using a heat exchanger to condense and freeze water vapor, allowing for simultaneous removal of water and condensation of the hydrofluorocarbon, thereby simplifying equipment requirements and improving efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional dehydration processes using zeolite-packed columns are used, then water removal is achieved, but equipment size becomes large and complexity increases
Solution Approach 1:
The patent employs phase transition of water from vapor to liquid through condensation at elevated temperatures (40-100°C), eliminating the need for zeolite-packed columns. The water vapor in the hydrofluorocarbon stream is condensed into liquid water that can be easily separated, achieving effective dehydration with simple equipment rather than complex adsorption systems.
Solution Approach 2:
The patent changes the temperature parameter from conventional low-temperature dehydration to elevated temperature operation (40-100°C). This parameter change enables water condensation while maintaining hydrofluorocarbon vapor phase, allowing simple phase separation without requiring large-scale zeolite columns or complex equipment systems.
2Quantity of substance
If conventional dehydration processes are used, then water is removed, but the process becomes inefficient and requires large-scale equipment
Solution Approach 1:
By utilizing phase transition of water from vapor to liquid through controlled condensation at elevated temperatures, the patent achieves highly efficient dehydration. The liquid water formed can be easily separated from the hydrofluorocarbon vapor, providing rapid and effective water removal without the inefficiencies of conventional adsorption methods requiring large equipment.
3Manufacturing precision
If distillation is performed on crude hydrofluorocarbon containing water, then purification is attempted, but azeotropic mixture formation causes difficulties
Solution Approach 1:
The patent performs preliminary dehydration by condensing water vapor from the crude hydrofluorocarbon stream before distillation. This preliminary action removes the majority of water content, preventing azeotropic mixture formation during subsequent distillation and simplifying the purification process. The hydrofluorocarbon is dried to low water content prior to distillation, eliminating the need for complex azeotropic separation systems.
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 effectively reduces water content to near zero, simplifies dehydration operations, and reduces the load on subsequent distillation processes, enabling continuous and efficient production of 1,3,3-tetrafluoropropene without the need for large-scale equipment.
Implementation Method 1
cooling the hydrofluorocarbon or hydrochlorofluorocarbon in gaseous form containing at least water by a heat exchanger, thereby condensing and liquefying the hydrofluorocarbon or hydrochlorofluorocarbon
Implementation Method 2
freezing and solidifying the water
Data Source
AI summary
A process for dehydrating a hydrofluorocarbon or hydrochlorofluorocarbon, which can be done by simple equipment, and a continuous process of producing 1,3,3,3-tetrafluoropropene using the dehydration process. The dehydration process includes cooling the hydrofluorocarbon or hydrochlorofluorocarbon in gaseous form containing water with a heat exchanger, thereby condensing and liquefying the hydrofluorocarbon or hydrochlorofluorocarbon while freezing and solidifying the water. The 1,3,3,3-tetrafluoropropene production method includes a first step for fluorinating 1-chloro-3,3,3-trifluoropropene with hydrogen fluoride to obtain a mixture of 1,3,3,3-tetrafluoropropene, unreacted 1-chloro-3,3,3-trifluoropropene, hydrogen fluoride, hydrogen chloride and by-products, or dehydrofluorinating 1,1,1,3,3-pentafluoropropane to obtain a mixture of 1,3,3,3-tetrafluoropropene, unreacted 1,1,1,3,3-pentafluoropropane and by-products, a second step for removing acidic components, a third step for dehydrating the 1,3,3,3-tetrafluoropropene by the above dehydration process, and a fourth step for purifying the 1,3,3,3-tetrafluoropropene by distillation.