Propylene Ammoxidation Catalyst Uniformity via Spray Drying
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional molybdenum-iron-bismuth oxide catalysts for propylene or isobutylene partial oxidation and ammoxidation suffer from inefficiencies due to non-uniform distribution of catalytically active components and mechanical strength issues, leading to reduced conversion rates and yield of desired products like acrylonitrile or methacrylonitrile.
Innovation Solution
A process involving a metal oxide precursor fluid with dissolved molybdenum, bismuth, and iron oxide precursors, combined with an inert carrier, is spray-dried and calcined to produce a catalyst with improved uniformity and mechanical strength, enhancing the availability of catalytically active components for reactions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional coprecipitation methods are used to produce catalyst particles, then the catalytically active components are formed, but the components are non-uniformly distributed within the particles
Solution Approach 1:
The patent changes the physical state parameter of the catalytically active components from solid particles to dissolved state in the precursor solution. By dissolving the metal precursors (molybdenum, bismuth, iron, and other oxides) in a suitable solvent before spray-drying, the components can uniformly distribute throughout the solution and subsequently form uniform catalyst particles after calcination, eliminating the non-uniform distribution problem of conventional coprecipitation methods.
Solution Approach 2:
The patent introduces a solvent as an intermediary medium to dissolve the metal precursors and facilitate uniform distribution. The solvent acts as a carrier that enables all catalytically active components to mix homogeneously before the drying and calcination steps, ensuring uniform spatial distribution of active components within the final catalyst particles.
2Strength
If conventional production processes are used, then catalyst material is formed, but the mechanical strength is reduced due to large pore volume
Solution Approach 1:
The patent changes the pore volume parameter by controlling the drying and calcination conditions of the spray-dried precursor. The rapid drying in spray-drying creates a more compact particle structure with reduced pore volume compared to conventional methods, and subsequent controlled calcination maintains this compact structure while forming the active oxide phases, resulting in catalyst particles with improved mechanical strength.
3Productivity
If only a small portion of catalytically active components are in contact with reaction mixture, then the efficiency of catalyst is reduced
Solution Approach 1:
The patent changes the distribution parameter of catalytically active components from concentrated in solid particles to uniformly distributed throughout the catalyst structure. By dissolving precursors before particle formation and then calcining, the active components are dispersed uniformly throughout the entire catalyst volume, maximizing the surface area available for reaction and ensuring that a much larger fraction of the catalyst material is in contact with the reaction mixture.
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 results in highly efficient catalysts with improved catalytic effectiveness and mechanical strength, leading to increased conversion rates and yield of products such as acrylonitrile or methacrylonitrile, while minimizing the need for binders or additives.
Implementation Method 1
spray drying the suspension or slurry of the inert carrier in the metal oxide precursor fluid to obtain a spray-dried precursor material
Implementation Method 2
heating the spray-dried precursor material to obtain the catalyst material
Data Source
AI summary
The present disclosure relates generally to catalyst materials and processes for making and using them. More particularly, the present disclosure relates to molybdenum, bismuth and iron-containing metal oxide catalyst materials useful, for example, in the partial oxidation or ammoxidation of propylene or isobutylene, processes for making them, and processes for making acrolein, methacrolein, acrylonitrile, and methacrylonitrile using such catalysts.