Porous Mayenite Sintered Catalyst for Ammonia Reactor Strength
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing catalysts for ammonia synthesis lack sufficient mechanical strength and catalytic activity, making them unsuitable for industrial reactors where they need to withstand pressure and impact during loading.
Innovation Solution
A molded sintered body containing a mayenite type compound, an inorganic binder sintered material, and a transition metal, with specific content ratios and pore diameter ranges, ensuring high catalytic activity and crushing strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a solid catalyst is used for ammonia synthesis, then catalytic performance can be achieved, but mechanical strength is insufficient to withstand pressure and impact in industrial reactors
Solution Approach 1:
The patent uses a composite material system consisting of mayenite type compound particles (providing catalytic activity) combined with inorganic binder material (providing mechanical strength). The mayenite compound contains free oxygen ions that give catalytic properties, while the inorganic binder forms a rigid matrix that withstands mechanical stress, thus resolving the contradiction between catalytic performance and mechanical strength
Solution Approach 2:
The patent employs porous mayenite type compound particles with specific pore structures that maintain high surface area for catalysis while the porous framework provides structural integrity. The controlled porosity allows reactant diffusion while the binder material reinforces the particle structure to resist mechanical degradation under reactor conditions
2Strength
If catalyst molding is performed to improve mechanical strength, then structural integrity increases, but catalytic activity may be reduced
Solution Approach 1:
The patent applies local quality by concentrating the inorganic binder material at the interfaces and surfaces of mayenite particles, where it provides mechanical reinforcement without blocking the internal porous structures. The binder forms a network that connects particles while leaving the catalytically active surfaces and pores of mayenite exposed and accessible to reactants, thus maintaining high catalytic activity while achieving sufficient mechanical strength
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 molded sintered body achieves high catalytic activity and crushing strength, suitable for use in fixed bed reactors, with improved mechanical stability and catalytic performance.
Implementation Method 1
free oxygen ions in the mayenite type compound can be substituted with various anions, and all free oxygen ions can be substituted with electrons by holding the mayenite type compound at a high temperature under a particularly strong reducing atmosphere. It has been reported that the mayenite type compound substituted with electrons is a conductive mayenite type compound having good electron conduction properties
Implementation Method 2
It has been reported that a catalyst using C12A7 electride can be used as a catalyst for ammonia synthesis. This catalyst has high ammonia synthesis activity at a low temperature and a low pressure as compared with a conventional catalyst for ammonia synthesis
Implementation Method 3
The Haber-Bosch process is a process for producing ammonia by bringing nitrogen and hydrogen as raw materials into contact with a catalyst containing iron as a main component at a high temperature and a high pressure
Data Source
AI summary
A molded sintered body containing a mayenite type compound, an inorganic binder sintered material, and a transition metal, wherein a content of the inorganic binder sintered material is 3 to 30 parts by mass with respect to 100 parts by mass of the molded sintered body, and the molded sintered body has at least one pore peak in each of a pore diameter range of 2.5 to 20 nm and a pore diameter range of 20 to 350 nm. A method for producing the molded sintered body, including mixing a precursor of a mayenite type compound and a raw material of an inorganic binder sintered material to prepare a mixture; molding the mixture to prepare a molded body of the mixture; firing the molded body to prepare a fired product; and supporting a transition metal on the fired product to produce a molded sintered body.