Chromium Oxide Catalyzed Fluorination of 2-Chloro-3,3,3-Trifluoropropene
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Solution Overview
Problem
Current methods for producing 2,3,3-tetrafluoropropene, a potential refrigerant, face challenges such as low yield, high costs, and excessive waste due to the use of expensive reagents and difficult-to-obtain starting materials, as well as low selectivity in existing production processes.
Innovation Solution
A process involving the reaction of 2-chloro-3,3,3-trifluoropropene with hydrogen fluoride in the presence of a specific catalyst, such as chromium oxide or fluorinated chromium oxide, under controlled temperature, pressure, and oxygen supply conditions to achieve high selectivity and efficiency in producing 2,3,3-tetrafluoropropene, with the by-product 1,1,1,2,2-pentafluoropropane being recycled to enhance yield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If zinc is used as reagent in ethanol to produce HFC-1234yf, then the reaction can proceed in a single step, but the cost increases significantly and large amounts of waste are produced
Solution Approach 1:
The patent replaces expensive zinc with a cheaper catalytic system using chromium oxide or fluorinated chromium oxide. The catalyst can be used in small amounts and regenerated, eliminating the need for large quantities of consumable zinc metal while reducing waste generation.
Solution Approach 2:
The patent changes the reaction conditions from using zinc in ethanol to using hydrogen fluoride with chromium oxide catalyst under controlled temperature and pressure conditions. This parameter change transforms the reaction mechanism to achieve the same product with fewer waste byproducts.
2Productivity
If existing production methods are used, then various compounds can be produced, but the selectivity of HFC-1234yf is low (40-60%)
Solution Approach 1:
The patent introduces hydrogen fluoride as an intermediary reactant that selectively reacts with 2-chloro-3,3,3-trifluoropropene in the presence of chromium oxide catalyst. This intermediary facilitates high-selectivity fluorodehydrochlorination to produce HFC-1234yf with selectivity exceeding 90%.
Solution Approach 2:
The patent uses fluorinated chromium oxide as a highly active catalyst that accelerates the selective fluorination reaction. The fluorinated surface of the chromium oxide provides strong catalytic activity that enhances reaction selectivity and rate, allowing high-selectivity production of HFC-1234yf.
3Ease of operation
If conventional catalysts are used, then the reaction can proceed, but the selectivity and efficiency are insufficient for industrial production
Solution Approach 1:
The patent employs fluorinated chromium oxide as a composite catalyst material that combines the structural framework of chromium oxide with surface fluorine atoms. This composite structure provides both the mechanical stability needed for industrial operation and the enhanced catalytic selectivity required for high-efficiency HFC-1234yf production.
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 selectivity and efficiency in producing 2,3,3-tetrafluoropropene, reducing waste and operational costs, and allows for the effective use of 1,1,1,2,2-pentafluoropropane as an intermediate, making the process more industrially viable.
Implementation Method 1
reacting 2-chloro-3,3,3-trifluoropropene with hydrogen fluoride in the presence of oxygen and a catalyst comprising chromium oxide
Data Source
Figure 1~2
AI summary
The present invention provides an effective, selective, and industrially applicable process for producing 2,3,3,3-tetrafluoropropene. Specifically, the present invention provides a process for producing 2,3,3,3-tetrafluoropropene including reacting 2-chloro-3,3,3-trifluoropropene with hydrogen fluoride in the presence of oxygen and a catalyst comprising chromium oxide represented by the composition formula: CrOm (1.5 < m <3), or fluorinated chromium oxide obtained by fluorinating the chromium oxide.