Composite Oxide Catalyst Particle Size Distribution Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional antimony-containing composite oxide catalysts for oxidation and ammoxidation reactions have insufficient yield, necessitating an improvement in catalyst production processes to enhance catalytic activity and product yield.
Innovation Solution
A process involving the preparation of an aqueous slurry with specific particle size distributions of iron and antimony components, followed by particle size reduction, drying, and calcination, to produce a composite oxide catalyst with optimized particle size proportions and calcination conditions, resulting in a catalyst with improved yield and catalytic activity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional catalyst preparation methods are used, then the catalyst can be produced with basic catalytic activity, but the yield of target product is insufficient
Solution Approach 1:
The patent applies parameter changes by optimizing the particle size distribution parameters of the catalyst precursor. Specifically, it controls the proportion of particles in different size ranges (0.5-5 μm, 5-10 μm, 10-20 μm, 20-50 μm, and 50-150 μm) to achieve maximum catalytic activity and target product yield. This involves adjusting preparation conditions such as mixing ratios, drying temperature, and calcination parameters to obtain the desired particle size distribution.
Solution Approach 2:
The patent applies segmentation by dividing the particle size distribution into multiple distinct ranges and controlling the proportion of particles in each range. Instead of treating the catalyst as a uniform material, it segments the particle population into five size categories and optimizes the distribution across these segments to enhance both catalytic activity and productivity.
2Productivity
If the particle size of precipitated particles is not controlled, then the catalyst preparation process is simple, but the catalytic performance and product yield are insufficient
Solution Approach 1:
The patent changes the particle size parameter by implementing precise control over the distribution of particle sizes in the catalyst precursor. It specifies target ranges for five different particle size intervals and adjusts preparation parameters (mixing, drying, calcination) to achieve this distribution, thereby improving product yield while maintaining manageable manufacturing precision requirements.
Solution Approach 2:
The patent applies local quality by assigning different optimal particle size ranges to different functional requirements of the catalyst. Smaller particles (0.5-10 μm) provide higher surface area for active sites, while larger particles (20-150 μm) provide structural stability. This local optimization of particle sizes throughout the distribution enhances overall catalytic performance.
3Reliability
If additives such as tellurium, vanadium, tungsten, molybdenum or phosphorus are added to iron and antimony, then catalytic performance is improved, but the catalyst composition becomes more complex
Solution Approach 1:
The patent applies the taking out principle by removing the complex multi-element additive system (tellurium, vanadium, tungsten, molybdenum, phosphorus) and replacing it with a simplified binary Fe-Sb system. Instead of adding multiple elements to enhance catalytic activity, it extracts the essential functionality into the iron-antimony combination, achieving high catalytic performance with a simpler composition.
Solution Approach 2:
The patent changes the compositional parameters by focusing on optimizing the ratios and particle size distribution of just iron and antimony components, rather than managing multiple additive elements. This parameter optimization approach achieves enhanced catalytic activity through controlled particle morphology and distribution rather than through complex multi-element chemistry.
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 process achieves a high yield of target products in ammoxidation reactions, particularly in the production of acrylonitrile and hydrocyanic acid, by optimizing the catalyst's particle size distribution and calcination stages, leading to enhanced catalytic performance and industrial applicability.
Implementation Method 1
a step of subjecting solid particles within the aqueous slurry to a particle size reduction treatment using a homogenizer
Implementation Method 2
a step of drying the aqueous slurry to obtain a dried material
Implementation Method 3
a step of calcining the obtained dried material
Data Source
AI summary
A process for producing a composite oxide catalyst which includes a step of preparing an aqueous slurry containing at least iron and antimony and composed of a liquid phase and a solid phase, a step of drying the aqueous slurry to obtain a dried material, and a step of calcining the obtained dried material, wherein of the precipitated particles having a particle size of not less than 1 µm but less than 150 µm contained within the aqueous slurry, the proportion of precipitated particles having a particle size of not less than 1 µm but less than 10 µm is within a range from 40 to 90% by volume, and the proportion of precipitated particles having a particle size of not less than 10 µm but less than 150 µm is within a range from 10 to 60% by volume.