Tetragonal Zirconia Catalyst for Ambient Pressure Methanation
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Solution Overview
Problem
Current catalysts for methane production through hydrogenation of carbon dioxide or carbon monoxide require high pressures due to slow reaction rates, making them inefficient for mass production and practical application.
Innovation Solution
A catalyst comprising a tetragonal zirconia structure with iron group elements like Ni and Co, supported on tetragonal zirconia with stabilizing elements such as Y, La, and Ce, is developed using a one-step method where all components are mixed and calcined, allowing for high activity and selectivity at ambient pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If conventional catalysts (Raney nickel, alumina-supported catalysts) are used for methane production, then the reaction can proceed under standard conditions, but the reaction rate is slow requiring high pressure operation
Solution Approach 1:
The patent employs a composite catalyst system consisting of iron group elements (Ni, Co, Fe) supported on tetragonal zirconia with stabilizing elements (Y, La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Eu, Mg, Ca). This composite structure combines the high catalytic activity of iron group metals with the structural stability and oxygen storage capacity of stabilized zirconia, achieving both high reaction rates and ambient pressure operation.
Solution Approach 2:
The patent changes the chemical and physical parameters of the catalyst by using tetragonal zirconia with specific stabilizing elements in controlled amounts (1-20 atomic %). This parameter optimization enables the catalyst to achieve high activity at ambient pressure while maintaining structural stability during operation.
2Productivity
If ribbon-shaped amorphous alloys prepared by rapid quenching are used as catalysts, then methane selectivity reaches almost 100% and conversion rate is very fast at ambient pressure, but the production process is not suitable for mass production and applicable systems are limited
Solution Approach 1:
The patent replaces the complex rapid quenching process with a simpler, more scalable preparation method using conventional ceramic processing techniques. The catalyst can be produced as powders, pellets, or structured forms suitable for industrial applications, making it economically viable for mass production while maintaining high conversion rates.
Solution Approach 2:
The patent changes the physical form of the catalyst from ribbon-shaped amorphous alloys to powder or structured forms supported on tetragonal zirconia. This parameter change maintains the high catalytic activity and methane selectivity while enabling easier handling, mass production, and integration into various reactor systems.
3Ease of manufacture
If Ni and/or Co are impregnated onto pre-prepared tetragonal zirconia-type oxide, then the catalyst can be produced through a two-step process, but subsequent research shows that preparing oxide containing all components and subsequent reduction gives better performance
Solution Approach 1:
The patent merges the preparation of the zirconia support and the iron group element incorporation into a single step by preparing oxide containing all components (Zr, stabilizing elements, and iron group elements) followed by one-step reduction. This combined approach ensures better distribution of active metal species and improved catalyst performance compared to sequential impregnation methods.
Solution Approach 2:
The patent performs preliminary mixing of all oxide precursors (zirconia, stabilizing elements, and iron group elements) before reduction. This preliminary action ensures homogeneous distribution of all components in the final catalyst, leading to better performance while simplifying the overall production process to a single reduction step.
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 achieves nearly 100% methane selectivity and high conversion rates at temperatures below 250°C, eliminating the need for high-pressure processes and simplifying the production and recycling of reactants.
Implementation Method 1
catalyst for methanation or formation of methane by reaction of hydrogen with carbon dioxide, a mixture of carbon monoxide and dioxide, or a mixed gas containing them as the main components
Implementation Method 2
comprises an iron group element: 25-80 atomic %; and in the catalyst the iron group element is supported on the oxide of the tetragonal zirconia structure in which not only the stabilizing element but also a portion of the iron group element is incorporated to stabilize the tetragonal zirconia structure
Data Source
AI summary
Disclosed is a catalyst for methanation reaction producing methane with high conversion by reaction of hydrogen with carbon dioxide, or a gas mixture of carbon dioxide and carbon monoxide, or a gas mixture containing these compounds as the main components. The catalyst is prepared by the steps of mixing (A) aqueous zirconia sol with salts of (B) stabilizing element(s), which is selected from the group consisting of Y, La, Ce, Pr, Nd, Sm, Gd, Dy, Ca and Mg, and (C) iron group element(s), drying and calcining the mixture to obtain a catalyst precursor, and subsequent reduction of the precursor. The catalyst comprises, by atomic %, A: 18-70%, B: 1-20% and C: 25-80% based on the elemental states of the metals. The catalyst is characterized by multiple oxide of tetragonal zirconia structure, in which not only the stabilizing element(s) but also a part of the iron group element(s) is incorporated, and on which the iron group element(s) in the metallic state is supported.