Alkane Dehydrogenation Catalyst with Lanthanides
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Solution Overview
Problem
Current methods for producing alkenes from alkanes, such as dehydrogenation and oxidative dehydrogenation, face challenges including low selectivity, coking, and safety issues due to high reaction temperatures and the use of hazardous substances like oxygen and CO2.
Innovation Solution
A method involving a catalyst comprising palladium and/or platinum with lanthanides, used in a mixture with high carbon dioxide concentrations, to convert alkanes into alkenes at moderate temperatures, avoiding the need for steam and oxygen, and allowing for efficient oxidative dehydrogenation without significant fragmentation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If dehydrogenation is performed at high temperature to overcome equilibrium limitations, then conversion rate is improved, but selectivity deteriorates and coking occurs
Solution Approach 1:
The patent changes the chemical composition parameters of the catalyst system by incorporating specific metal combinations (e.g., Pt-Sn, Pd-Zn) and support materials (calcium-aluminium) to modify the reaction pathway and lower the activation energy, enabling high conversion at reduced temperatures while maintaining selectivity
Solution Approach 2:
The patent employs composite catalyst structures combining multiple metals (e.g., platinum-tin, palladium-zinc) on specific supports (calcium-aluminium) to create synergistic effects that enhance both activity and selectivity, resolving the contradiction between conversion rate and selectivity
2Productivity
If oxidative dehydrogenation with oxygen is used to facilitate the reaction, then conversion is improved, but safety issues arise due to explosive limits
Solution Approach 1:
The patent replaces oxygen with carbon dioxide as the oxidizing agent, creating an inert reaction environment that eliminates explosive hazards while maintaining the ability to facilitate dehydrogenation through CO2 participation in the reaction mechanism
3Productivity
If CO2 is used for oxidative dehydrogenation at 600-650°C, then conversion is achieved, but coking occurs
Solution Approach 1:
The patent significantly lowers the reaction temperature parameter from 600-650°C to below 500°C by introducing novel catalyst systems, which suppresses coking while maintaining effective conversion through enhanced catalytic activity at lower temperatures
4Productivity
If chromia or platinum-tin catalysts are used for dehydrogenation, then conversion is improved, but catalyst deactivation occurs due to coke deposition
Solution Approach 1:
The patent develops composite catalyst formulations combining metal nanoparticles (Pt, Pd) with specific support materials and promoters (Sn, Zn, calcium-aluminium) that create resistant structures against coke deposition, extending catalyst lifetime while maintaining high conversion activity
Solution Approach 2:
The patent modifies the operational temperature parameter to below 500°C, which kinetically suppresses coke formation rates, thereby extending catalyst lifetime without sacrificing conversion efficiency through the enhanced catalytic activity of the novel catalyst system
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 enables the production of alkenes under mild conditions, achieving high conversion rates and selectivity while minimizing unwanted byproducts and catalyst degradation, allowing for high gas hourly space velocities and effective catalyst regeneration.
Implementation Method 1
Contacting said mixture with a catalyst comprising (a) one or both of palladium and platinum, and (b) one or more lanthanide, thereby converting at least a portion of the at least one compound comprising an alkyl group having two or more carbon atoms into a compound comprising an alkenyl group
Implementation Method 2
Alternatively, oxygen may be used to facilitate an oxidative dehydrogenation of the alkane to form the alkene and water
Data Source
Figure 1~2
Figure 3~4
AI summary
A method of producing at least one compound comprising an alkenyl group from at least one compound comprising an alkyl group having two or more carbon atoms, the method comprising: (i) Providing a mixture comprising carbon dioxide and at least one compound comprising an alkyl group having two or more carbon atoms; and (ii) Contacting said mixture with a catalyst comprising one or both of palladium and platinum and one or more lanthanide, thereby converting at least a portion of the at least one compound comprising an alkyl group having two or more carbon atoms into a compound comprising an alkenyl group, the total of the weight of the palladium and/or platinum being more than 0.1wt% of the catalyst.