Propylene Ammoxidation Catalyst with Wear-Resistant Silica Support
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Solution Overview
Problem
Existing ammoxidation catalysts for propylene, particularly those prepared by the sol-gel method, suffer from low yield, high fine powder content, and poor durability due to weak particle binding, necessitating continuous replenishment and increased manufacturing costs.
Innovation Solution
An ammoxidation catalyst with a controlled pore diameter and apparent density of the silica support, combined with a specific metal oxide composition, is prepared using an impregnation method, resulting in improved durability and reduced fine powder content, allowing for high-yield acrylonitrile production without additional catalyst supply.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the sol-gel method is used to prepare the catalyst, then the catalyst can be manufactured with a specific composition, but the particle binding force is weak causing high fine powder content and poor durability
Solution Approach 1:
The patent uses a composite structure consisting of a silica support material combined with metal oxide particles (Mo-Bi-based). This composite approach creates strong binding between the metal oxide and silica, forming durable secondary particles that resist attrition and fine powder generation while maintaining the desired catalytic composition.
Solution Approach 2:
The silica support is designed with controlled porosity parameters (pore diameter 3-20 nm, apparent density 0.2-1.2 g/cc). This porous structure provides a robust framework that strongly binds metal oxide particles, preventing their detachment and fine powder formation during reactor operation, while maintaining catalytic activity.
2Ease of manufacture
If the sol-gel method is used to prepare the catalyst, then the catalyst can be formed with metal oxide and silica particles, but the secondary particle structure has weak binding force causing particle wear and splitting
Solution Approach 1:
The patent creates a composite material system where metal oxide particles are strongly bound to a silica support matrix. This composite structure provides mechanical strength to secondary particles, preventing their wear and splitting during fluidized bed reactor operation, while maintaining the catalytic functionality of the metal oxide components.
Solution Approach 2:
The patent optimizes physical parameters of the silica support (pore diameter 3-20 nm, apparent density 0.2-1.2 g/cc) to enhance the binding strength between silica and metal oxide particles. These parameter adjustments create a more robust secondary particle structure that resists mechanical degradation.
3Ease of manufacture
If the sol-gel method is used, then the catalyst can be prepared by co-precipitation and spray-drying, but fine powder is generated due to insufficient aggregation resulting in low productivity and high manufacturing cost
Solution Approach 1:
The patent employs a porous silica support with controlled pore diameter (3-20 nm) and apparent density (0.2-1.2 g/cc) that promotes effective aggregation of metal oxide particles during the preparation process. This results in well-formed secondary particles with reduced fine powder content, improving both productivity and reducing manufacturing costs.
4Reliability
If catalyst is continuously replenished to compensate for wear, then catalytic activity can be maintained, but manufacturing cost increases and acrylonitrile yield improvement is limited
Solution Approach 1:
The patent creates a durable composite catalyst structure with strong binding between metal oxide and silica support, significantly reducing particle wear and fine powder generation. This enhanced durability allows the catalyst to maintain its activity throughout the reaction period without requiring continuous replenishment, thereby improving acrylonitrile yield and reducing operational costs.
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 exhibits enhanced durability and uniform particle size distribution, leading to higher acrylonitrile yields and reduced attrition loss, thus optimizing the ammoxidation process in a fluidized bed reactor.
Implementation Method 1
a method in which a metal precursor solution and silica sol are co-precipitated
Implementation Method 2
supporting a mixture of the first and second precursor aqueous solutions on a silica support
Data Source
AI summary
The present disclosure relates to an ammoxidation catalyst for propylene, a manufacturing method of the same, and an ammoxidation method of propylene using the same. Specifically, in one embodiment of the present disclosure, there is provided a catalyst having a structure in which a metal oxide is supported on a silica support having a narrow particle size distribution, and excellent wear resistance.