Mesoporous Silica Foam Metathesis Catalyst for Propylene
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Solution Overview
Problem
Current propylene production methods, such as steam cracking and Fluid Catalytic Cracking, struggle to meet the increasing demand for propylene due to inadequate selectivity and deactivation of olefin metathesis catalysts, particularly in converting butenes to propylene efficiently.
Innovation Solution
An amorphous mesoporous silica foam impregnated with metal oxides, specifically tungsten oxide, is used as a metathesis catalyst with a pore size distribution of 3-40 nm and a surface area of 400-500 m^2/g, enhancing selectivity and reducing deactivation by maintaining high dispersion of metal oxide species.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional olefin metathesis catalysts are used to convert butenes to propylene, then propylene production can be achieved, but catalyst deactivation due to coking from aromatic products occurs and selectivity is insufficient
Solution Approach 1:
The patent employs a mesoporous silica foam support with controlled pore sizes (3-40 nm) and high surface area (400-500 m²/g) to disperse metal oxide catalyst species. The porous structure provides high dispersion of catalytic sites while preventing coking-induced deactivation through appropriate pore size control, thereby maintaining catalyst stability during propylene production
Solution Approach 2:
The patent creates a composite catalyst system combining metal oxides (such as tungsten oxide) impregnated on a mesoporous silica foam support. This composite structure synergistically combines the catalytic activity of metal oxides with the high surface area and structural stability of the silica foam, achieving both high propylene production rates and resistance to catalyst deactivation
2Productivity
If conventional olefin metathesis catalysts are used, then metathesis reaction can proceed, but selectivity to propylene is insufficient leading to side reactions
Solution Approach 1:
The patent applies local quality by creating specific active sites through metal oxide impregnation on the mesoporous silica foam. The controlled distribution of metal oxide species within the porous structure provides localized catalytic centers with optimized geometry and electronic properties that selectively promote propylene formation while minimizing side reactions
Solution Approach 2:
The mesoporous silica foam with its controlled pore size distribution (3-40 nm) and high surface area provides a structured environment that enhances selectivity. The porous structure facilitates selective access of reactants to active sites and controls product diffusion, thereby improving propylene selectivity and reducing unwanted side reactions
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 approach significantly increases propylene yield while minimizing side reactions and catalyst deactivation, achieving higher conversion rates of 2-butene to 1-butene and subsequent propylene production with reduced aromatics formation.
Implementation Method 1
converting a stream comprising butenes to propylene via metathesis using an amorphous mesoporous silica foam metathesis catalyst
Implementation Method 2
an amorphous mesoporous silica foam impregnated with metal oxides
Data Source
Figure 1~3
Figure 4
AI summary
Embodiments of a metathesis process for producing propylene comprise providing a metathesis catalyst comprising an amorphous mesoporous silica foam impregnated with metal oxides, where the metathesis catalyst has a pore size distribution of at least 3 nm to 40 nm and a total pore volume of at least 0.700 cm3/g. The process further involves producing a product stream comprising propylene by contacting a feed stream comprising butene with the metathesis catalyst.