Bonded Honeycomb Catalyst Segments for Flexible SCR Geometry
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Solution Overview
Problem
Honeycomb SCR catalyst bodies with square or rectangular cross-sectional profiles are limited in application due to their geometry, which hinders their use in various fields, and existing denitration technologies face challenges in effectively reducing nitrogen oxides in exhaust gases while meeting stringent emission standards.
Innovation Solution
The development of catalytic assemblies comprising bonded honeycomb catalyst segments with a chemical composition of 50-99.9 weight percent inorganic oxide and at least 0.1 weight percent catalytically active metal functional groups, using ceramic cement as a bonding material, allowing for flexible geometry and enhanced nitrogen oxide reduction capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If honeycomb catalyst bodies are provided with square or rectangular cross-sectional profile to facilitate assembly and packing, then ease of manufacture and assembly are improved, but adaptability to various fields and applications is limited
Solution Approach 1:
The catalyst body is divided into multiple honeycomb catalyst segments that can be bonded together in different configurations. This segmentation allows the catalyst to be manufactured using standard square or rectangular segments while enabling flexible assembly into various geometries (circular, triangular, custom shapes) to meet different application requirements.
Solution Approach 2:
The invention transitions from fixed 2D cross-sectional geometry to 3D configurable geometry by bonding multiple segments together. This dimensional approach allows standard segments to be combined in various arrangements (side-by-side, stacked, circular patterns) to create catalyst bodies with different external profiles suitable for different reactor configurations.
2Reliability
If non-bonding compressible packing materials are used between catalyst bodies for proper flow distribution, then fluid flow distribution is improved, but mechanical strength and structural stability deteriorate
Solution Approach 1:
The invention merges the flow distribution function and structural support function into a single bonding material that simultaneously provides mechanical bonding between segments and maintains proper fluid flow pathways. This eliminates the need for separate packing materials and resolves the conflict between structural strength and flow distribution.
Solution Approach 2:
The bonding material used is a composite composition (such as ceramic cement or refractory concrete) that combines the properties of structural adhesives with flow distribution characteristics. This composite material provides both the mechanical strength needed for structural stability and the appropriate porosity or channel structure for proper gas flow distribution between catalyst segments.
3Strength
If honeycomb catalyst segments are bonded using ceramic cement, then mechanical strength and structural integrity are improved, but manufacturing complexity and processing difficulty increase
Solution Approach 1:
The bonding material is applied to the catalyst segments before final assembly and positioning. This preliminary application allows the bonding material to be properly distributed and cured in place, ensuring maximum structural integrity while simplifying the overall manufacturing process by avoiding complex post-assembly bonding operations.
Solution Approach 2:
The bonding material is designed to self-level or self-distribute between segments during assembly, reducing the need for precise manual positioning or complex bonding equipment. The material's properties (viscosity, cure time, shrinkage characteristics) are selected to enable automatic flow and distribution, simplifying the manufacturing process while ensuring consistent bonding quality.
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 bonded catalytic assemblies provide a flexible geometry and improved efficiency in reducing nitrogen oxides in exhaust gases, meeting stringent emission standards and enabling broader application across different fields.
Implementation Method 1
The catalytically active metal functional group, in some embodiments, is operable for the selective catalytic reduction of nitrogen oxides
Data Source
AI summary
In one aspect, catalytic assemblies are described herein. A catalytic assembly, in some embodiments, comprises a plurality of honeycomb catalyst segments bonded to one another by a bonding material, the honeycomb catalyst segments comprising an outer peripheral wall and a plurality of inner partition walls defining flow channels extending longitudinally through the catalyst segments, wherein the outer peripheral wall and inner partition walls have dispersed throughout a chemical composition comprising 50-99.9 weight percent an inorganic oxide composition and at least 0.1 weight percent a catalytically active metal functional group.