1233zd Purification via Phase Separation and Scrubbing
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Solution Overview
Problem
Current methods for producing 1-chloro-3,3,3-trifluoropropene (1233zd) on a commercial scale face challenges in efficiently separating and purifying the product from byproducts like HCl and HF, especially at high pressures, due to incomplete phase separation when HCl is present.
Innovation Solution
A high-pressure process involving a reactor for reacting 1,1,1,3,3-pentachloropropane (240fa) with HF, followed by distillation, phase separation, and scrubbing to remove HCl and recover HF, allowing for recycling and subsequent purification of 1233zd to meet commercial specifications, with optional catalysts like TiCl4 and SbCl5, and drying agents such as sulfuric acid or molecular sieves.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If phase separation is used to separate HF from the reaction mixture, then HF recovery is achieved, but complete separation fails when HCl is present in the mixture
Solution Approach 1:
The patent divides the separation process into distinct stages: first separating HF from the reaction mixture through phase separation, then separately removing HCl through scrubbing. This segmentation allows each separation step to be optimized independently, achieving complete removal of both HF and HCl without interference between the two separation processes.
Solution Approach 2:
The patent performs preliminary removal of HCl from the reaction mixture before attempting to separate HF. By removing HCl first through scrubbing, the subsequent phase separation of HF is not interfered with, ensuring complete and efficient HF recovery. This preliminary action eliminates the interfering substance that would otherwise prevent complete separation.
2Manufacturing precision
If multiple purification steps are implemented, then product purity is improved, but process complexity increases
Solution Approach 1:
The patent combines multiple purification functions into an integrated system where the reaction mixture is processed through phase separation and scrubbing in a coordinated sequence. The HF recovery unit and HCl removal unit work together as a unified purification system, achieving high product purity (99.5% GC) while managing process complexity through functional integration rather than completely separate independent 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 process effectively produces 1233zd with high purity (99.5% GC) and low byproduct levels, addressing the separation and purification challenges by removing HCl first, facilitating efficient recycling and recovery of HF and HCl, and achieving commercial product standards.
Implementation Method 1
the bottom stream from the second distillation column is then phase separated to recover HF
Implementation Method 2
the overhead product from the distillation column is fed to a second distillation column to remove the HCl
Implementation Method 3
the HCl in the overhead stream is scrubbed with water and recovered as an aqueous solution
Data Source
AI summary
The present invention is directed to processes for the production of 1233zd from 240fa and HF, with or without a catalyst, at a commercial scale. The 240fa and HF are fed to a reactor operating at high pressure. The resulting product stream comprising 1233zd, HCl, HF, and other byproducts is treated to one or more purification techniques including phase separation and one or more distillations to provide purified 1233zd, which meets commercial product specifications, i.e., having a GC purity of 99.5% or greater.