Ionic Liquid Coated Catalyst for Selective Hydrogenation
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Solution Overview
Problem
Current catalysts for selective hydrogenation of acetylenic hydrocarbons face challenges in achieving high selectivity and activity while maintaining thermal stability, particularly due to the high cost and reduced activity associated with using catalysts with high specific surface areas and suitable pore volumes for coating with ionic liquids.
Innovation Solution
A catalyst system is developed using conventional heterogeneous catalysts with a BET surface area of ≤9 m2/g coated with a small amount of ionic liquid, achieving high selectivity and activity in the hydrogenation of acetylene to ethylene with a higher 'run-away' temperature, and using very small quantities of ionic liquid (≤3% by weight) to minimize activity loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If catalysts with high specific surface area and suitable pore volume are used for coating with ionic liquids, then selectivity and activity are improved, but cost increases and activity loss occurs
Solution Approach 1:
The patent changes the BET surface area parameter from high values to specifically ≤9 m2/g, and controls pore volume at ≤0.07 ml/g. These parameter modifications enable effective ionic liquid coating while reducing the quantity of ionic liquid required, thereby lowering cost without sacrificing selectivity or activity
Solution Approach 2:
The patent utilizes catalysts with controlled porous structure (low pore volume ≤0.07 ml/g) that are suitable for ionic liquid coating. The porous structure allows adequate ionic liquid penetration and anchoring while minimizing the total amount of ionic liquid needed, thus reducing cost while maintaining reliability
2Reliability
If ionic liquid is applied to catalyst surface, then selectivity is improved, but activity is reduced
Solution Approach 1:
The patent optimizes the BET surface area to ≤9 m2/g and pore volume to ≤0.07 ml/g, which controls the amount of ionic liquid that can be effectively coated. This parameter optimization ensures that sufficient ionic liquid is present to improve selectivity while preventing excessive coating that would block active sites and reduce activity
Solution Approach 2:
The patent applies a controlled, limited amount of ionic liquid to the catalyst surface rather than maximizing coverage. This partial action approach provides enough ionic liquid to enhance selectivity through specific interactions at active sites while leaving sufficient exposed catalyst surface area to maintain high activity
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 system exhibits improved selectivity and activity during acetylene hydrogenation in ethylene-rich gas streams with a broader operation window and reduced catalyst activity loss, while also reducing costs associated with ionic liquid usage.
Implementation Method 1
an ionic liquid applied to the surface of the same
Implementation Method 2
catalyst composition for selective hydrogenation with improved characteristics
Data Source
AI summary
This invention relates to heterogeneous catalysts useful for selective hydrogenation of unsaturated hydrocarbons, comprising palladium and optionally a promoter, supported on a substrate, having an uncoated BET surface area of ≤9 m2/g, the surface being coated with an ionic liquid. Also described are methods of making the catalysts and methods of selective hydrogenation of acetylene and/or dienes in front-end mixed olefin feed streams.