Ethylene Oxide Catalyst Optimized Cesium Content
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional silver-based ethylene oxide catalysts suffer from low selectivity, which limits their economical feasibility and requires high operating temperatures when cesium content is excessive, affecting catalyst performance and productivity.
Innovation Solution
A silver-based catalyst with a bimodal pore size distribution and optimized cesium content up to 700 ppm, featuring a refractory support with a catalytically effective amount of silver and rhenium, enhances selectivity and activity, allowing operation under typical conditions without the need for extreme temperature conditioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If cesium content is increased to improve selectivity, then selectivity is improved, but operating temperature must be increased which negatively affects selectivity and productivity
Solution Approach 1:
The patent optimizes the cesium content parameter to a specific range (50-700 ppm) to achieve the desired selectivity without requiring excessive operating temperatures. This parameter optimization resolves the contradiction by finding the optimal balance point where selectivity is improved while maintaining reasonable operating temperature levels.
2Manufacturing precision
If cesium content is increased to improve selectivity, then selectivity is improved, but productivity is reduced due to high operating temperatures
Solution Approach 1:
By precisely controlling the cesium content within the range of 50-700 ppm, the patent achieves high selectivity while avoiding the productivity loss that would result from excessively high operating temperatures. This parameter optimization simultaneously addresses both selectivity and productivity concerns.
3Device complexity
If conventional silver-based catalysts are used, then catalyst simplicity is maintained, but selectivity is low requiring high operating temperatures
Solution Approach 1:
The patent creates a composite catalyst system by combining silver with controlled amounts of cesium (50-700 ppm) and rhenium on an alumina support. This composite approach significantly improves selectivity compared to conventional silver-based catalysts while maintaining reasonable operational complexity through precise compositional control.
4Productivity
If high operating temperatures are used to maintain productivity with high cesium content, then productivity is maintained, but selectivity is negatively affected
Solution Approach 1:
The patent resolves this contradiction by optimizing the cesium content parameter to 50-700 ppm, which enables the catalyst to achieve both high productivity and high selectivity at moderate operating temperatures, eliminating the need to choose between these conflicting performance metrics.
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 catalyst achieves high selectivity and productivity while maintaining operational efficiency at normal temperatures, reducing yearly operating costs and improving ethylene oxide production.
Implementation Method 1
The catalytic epoxidation of an olefin by use of silver-based catalysts is well known in the art
Implementation Method 2
a bimodal pore size distribution in the carrier has been found to be highly beneficial in optimizing the activity and selectivity of the catalyst
Data Source
AI summary
The invention is directed to a catalyst useful in the epoxidation of an olefin to an olefin oxide, the catalyst comprising a support having a multimodal pore size distribution comprising a first and a second distribution of pore sizes wherein each distribution of pore sizes possesses a different mean pore size and a different pore size of maximum concentration, the support having a catalytically effective amount of silver, a promoting amount of rhenium, and cesium in an amount up to, but not exceeding 700 ppm disposed thereon. The invention is also directed to methods for using the catalyst for the commercial production of an olefin oxide from olefin and oxygen-containing feed gases.