Modified FER Zeolite Catalyst for Alcohol Dehydration
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Solution Overview
Problem
Conventional catalysts for alcohol dehydration to produce olefins suffer from rapid deactivation and limited regenerability, leading to inefficient production of linear olefins and increased downstream separation costs.
Innovation Solution
A modified crystalline aluminosilicate catalyst with a Si/Al framework molar ratio greater than 20 and a strong to weak acid site ratio below 1.0, prepared without steaming, using an organic acidic medium and selective poisoning to reduce extra framework aluminum content, enhancing regenerability and selectivity towards linear olefins.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional dehydration catalysts are used, then alcohol conversion to olefins is achieved, but catalyst deactivation occurs rapidly and regenerability is limited
Solution Approach 1:
The patent modifies the crystalline aluminosilicate catalyst by changing the Si/Al framework molar ratio to greater than 20 and controlling the strong to weak acid site ratio to below 1.0. This parameter optimization resolves the contradiction by creating a catalyst that maintains high alcohol conversion efficiency while significantly improving resistance to deactivation and enhancing regenerability through reduced coke formation.
Solution Approach 2:
The patent selectively removes extra framework aluminum from the catalyst structure through controlled treatment processes. This extraction of harmful aluminum species reduces the strong acid site density that promotes coke formation, thereby extending catalyst lifespan and improving regenerability while maintaining sufficient catalytic activity for olefin production.
2Productivity
If conventional catalysts are used, then dehydration reaction proceeds, but selectivity towards linear olefins is insufficient
Solution Approach 1:
The patent creates localized differences in acid site distribution within the catalyst structure by controlling the spatial arrangement of aluminum atoms in the framework. The modified crystalline aluminosilicate provides specific local environments with optimized acid strength and distribution that favor the formation of linear olefin isomers over branched isomers, achieving high selectivity while maintaining production rate.
3Manufacturing precision
If catalyst treatment is performed to improve selectivity, then linear olefin production increases, but catalyst complexity increases
Solution Approach 1:
The patent incorporates the selectivity-enhancing modifications directly into the catalyst synthesis process itself, rather than requiring separate post-synthesis treatment steps. By controlling the crystallization conditions and framework composition during catalyst formation, the desired Si/Al ratio and acid site distribution are achieved in a single integrated process, reducing overall complexity.
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 modified catalyst achieves complete conversion of alcohols to olefins with high selectivity and improved regenerability, reducing coke formation and extending catalyst lifespan, thus enhancing process efficiency and reducing downstream separation costs.
Implementation Method 1
The present invention relates generally to the field of dehydration of alcohols on acidic catalysts to make corresponding olefins
Implementation Method 2
Solid acid catalysts are widely used for alcohol dehydration
Data Source
AI summary
The present invention relates to a catalyst composition comprising a modified crystalline aluminosilicate of the Framework Type FER having Si/Al framework molar/ratio greater than 20 characterized in that in said modified crystalline aluminosilicate the ratio between the strong acid sites and the weak acid sites, S/W, is lower than 1.0 and having the extra framework aluminum (EFAL) content lowered to less than 10 wt % preferably 5 wt % even more preferably less than 2 wt % measured by 27Al MAS NMR. The present invention further relates to a process for producing olefins from alcohols in presence of said catalyst composition.