Ammoxidation Catalyst Production via Controlled Particle Size
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Solution Overview
Problem
Existing methods for producing catalysts for acrylonitrile ammoxidation are insufficient in improving yield due to instability issues caused by particle size adjustments, leading to reduced catalyst performance.
Innovation Solution
A method involving the preparation of a catalyst precursor slurry with metal primary particles of specific sizes (40 nm to 200 nm) and a composite metal oxide composition, followed by precise drying and calcination conditions, to enhance catalyst stability and acrylonitrile yield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If homogenizer treatment and ultrasonic treatment are carried out to adjust particle size, then the particle size of aggregate is reduced, but the slurry loses stability due to reaggregation of pulverized primary particles
Solution Approach 1:
The patent applies preliminary action by controlling the particle size of metal primary particles to be 1 μm or smaller and the average particle size to be 40-200 nm before aggregate formation. This pre-control prevents subsequent reaggregation and maintains slurry stability throughout the catalytic process.
Solution Approach 2:
The patent changes the particle size parameter of metal primary particles to a specific range (40-200 nm average size) to optimize both catalytic performance and slurry stability. This parameter optimization prevents the harmful reaggregation that occurs with larger particles.
2Shape
If metal primary particles are pulverized to reduce particle size, then the interaction between particles is increased, but catalyst performance is reduced due to loss of slurry stability
Solution Approach 1:
The patent optimizes the particle size parameter of metal primary particles to an average of 40-200 nm, which is sufficient to provide adequate interaction between particles for catalysis while being small enough to maintain slurry stability and prevent reaggregation during the catalytic process.
Solution Approach 2:
The patent performs preliminary particle size control to ensure metal primary particles are within the optimal range before aggregate formation. This pre-control ensures that the particles will maintain stability throughout the catalytic process and not undergo harmful reaggregation.
3Ease of manufacture
If conventional catalyst production methods are used, then the process is simple, but the acrylonitrile yield is insufficient
Solution Approach 1:
The patent changes the particle size parameter of metal primary particles to 40-200 nm average size, which optimizes the balance between catalytic activity (for higher acrylonitrile yield) and slurry stability. This parameter optimization achieves both high productivity and maintained process simplicity.
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 method results in a catalyst with improved acrylonitrile yield by optimizing particle sizes and composition, leading to increased reaction efficiency and stability during the ammoxidation process.
Implementation Method 1
a method for producing a catalyst for ammoxidation... reacting propylene, molecular oxygen, and ammonia
Data Source
AI summary
The present invention provides a method for producing a catalyst for ammoxidation, comprising steps of: preparing a catalyst precursor slurry comprising a liquid phase and a solid phase; drying the catalyst precursor slurry to obtain dry a particle; and calcining the dry particle to obtain a catalyst for ammoxidation, wherein the solid phase of the catalyst precursor slurry comprises an aggregate containing a metal and a carrier, metal primary particles constituting the aggregate have a particle size of 1 μm or smaller, and an average particle size of the metal primary particles is 40 nm or larger and 200 nm or smaller.