Chromium-Nickel Catalyst for Selective Dehydrofluorination
Solution Overview
Problem
Current processes for producing fluorinated compounds like HFO 1234yf and HFO 1225ye from HFCs 245eb and 236ea respectively, face challenges in achieving high selectivity and conversion rates, leading to suboptimal yields and productivity.
Innovation Solution
A selective dehydrofluorination process using a mixed catalyst based on chromium and nickel on an aluminum-based support, optimized for temperature, contact time, and hydrogen ratio, to enhance conversion and selectivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional single-metal catalysts (chromium or nickel) are used for dehydrofluorination, then the process is simpler to implement, but conversion rates and selectivity remain suboptimal
Solution Approach 1:
The patent employs a composite catalyst comprising chromium oxide and nickel oxide supported on alumina. This composite material combines the dehydrofluorination activity of chromium oxide with the hydrogenation capability of nickel oxide, achieving synergistic effects that improve both conversion rate (>80%) and selectivity (>90%) compared to conventional single-metal catalysts.
2Productivity
If temperature is increased to improve conversion rate, then productivity increases, but selectivity decreases leading to lower yield
Solution Approach 1:
The patent optimizes the temperature parameter to a specific range of 300-400°C, where the dual-function catalyst achieves both high conversion rate (>80%) and high selectivity (>90%). The chromium oxide component ensures high conversion while the nickel oxide component maintains selectivity by suppressing side reactions, resolving the typical trade-off between conversion and selectivity.
3Productivity
If contact time is extended to improve conversion, then productivity increases, but process efficiency decreases
Solution Approach 1:
The patent achieves high conversion rates (>80%) within a short contact time of 2-20 seconds by utilizing the high activity of the chromium-nickel dual-function catalyst. The synergistic catalytic system accelerates the dehydrofluorination reaction, allowing the process to reach high conversion quickly without requiring extended contact times, thus improving overall process efficiency.
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 (>80%) and selectivity (>90%) for HFO 1234yf and HFO 1225ye, resulting in increased productivity and yield.
Implementation Method 1
A selective dehydrofluorination process using a mixed catalyst based on chromium and nickel on an aluminum-based support
Data Source
AI summary
The invention relates to a method for selective dehydrofluorination on a mixed catalyst based on chromium and nickel on a carrier based on aluminium. The invention is used for the synthesis of 2, 3, 3, 3-tetrafluoro-1-propene and 1,2,3,3,3- pentafluoro-1-propene.