Catalyst-Containing Ceramic Filter Impregnation Using Microwave Drying

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Solution Overview

Problem

Existing methods for loading catalysts onto ceramic filters for off-gas or exhaust gas cleaning are inefficient, requiring high energy consumption due to dust cake formation and non-uniform catalyst distribution, leading to compromised mechanical properties and increased production costs.

Innovation Solution

A method involving microwave drying of a catalyst-containing slurry applied to the inner side of ceramic filters, leaving the outer shell dry, ensures uniform catalyst distribution and maintains mechanical integrity, reducing energy consumption and production costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the filter is fully impregnated with catalyst slurry, then catalytic performance is improved, but mechanical strength deteriorates

Engineering Contradiction:
Improvecatalytic performanceVSAvoidmechanical strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The filter is divided into two zones with different properties: an inner impregnated zone containing the catalyst slurry for catalytic activity, and an outer unimpregnated zone maintaining mechanical strength. This local differentiation resolves the contradiction by providing catalytic performance where needed while preserving structural integrity where required.

Inventive Principle:
Principle #3Local quality

2Use of energy by stationary object

If conventional drying methods are used, then energy consumption is high, but drying effectiveness is insufficient

Engineering Contradiction:
Improveenergy consumptionVSAvoiddrying effectiveness
Core Design Contradiction:
Use of energy by stationary objectVSProductivity

Solution Approach 1:

Conventional thermal drying is replaced with microwave drying, which uses electromagnetic radiation to directly heat and evaporate water in the catalyst slurry. This substitution achieves rapid and uniform drying with significantly reduced energy consumption and time, resolving the contradiction between energy input and drying effectiveness.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Manufacturing precision

If the outer shell is also impregnated, then catalyst distribution is uniform, but handling difficulty increases

Engineering Contradiction:
Improvecatalyst distribution uniformityVSAvoidhandling ease
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The filter is selectively impregnated only in the inner region while leaving the outer shell unimpregnated. This local quality approach ensures uniform catalyst distribution in the active zone while maintaining the outer shell's mechanical properties for easy handling, resolving the contradiction between manufacturing precision and ease of manufacture.

Inventive Principle:
Principle #3Local 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

Achieves efficient catalyst distribution, improved mechanical properties, and reduced energy requirements, resulting in a cost-effective and high-performance catalytic filter.

Implementation Method 1

drying the impregnation slurry and the filter using microwave energy to affix the catalytically active metal to the oxide support and the catalyst substrate

Methodology Applied
Scientific EffectMicrowave drying: Microwave Radiation

Data Source

PatentEP3356040B1Method for preparing a catalyst-containing ceramic filter for off-gas or exhaust gas cleaning
Publication Date: 2025.09.03 HALDOR TOPSOE AS
  • EP3356040B1 patent drawingFigure 1
  • EP3356040B1 patent drawingFigure 2
  • EP3356040B1 patent drawingFigure 3

AI summary

A catalyst-containing ceramic dust filter for off-gas or exhaust gas cleaning is prepared by a method comprising the steps of making a water-based impregnation slurry, which comprises a catalytically effective amount of at least one catalytically active metal and an oxide support, to form a catalytically active metal oxide support, impregnating the filter substrate with the impregnation slurry, spraying from the inside to control the amount of liquor while leaving the outer few millimeters of the filter wall dry, and drying the impregnated filter. The impregnated filter is preferably dried by using microwave energy.