SCR Catalyst Pluggage Removal via Dry Ice Blasting
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Solution Overview
Problem
Existing methods for removing fly ash particulates from SCR catalysts and systems are inadequate, leading to premature loss of catalytic performance, plugging of channels, and mechanical issues, especially since current dry cleaning methods can cause abrasion and chemical residue, and wet chemical regeneration is hindered by accumulated ash.
Innovation Solution
A method using a blasting stream of pressurized carrier gas and dry ice to remove accumulated fly ash from SCR catalysts, including honeycomb, corrugated, and plate types, by directing the stream at the flue gas inlet side, which effectively dislodges and removes particulates without chemical residue or mechanical damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If dry cleaning methods are used to remove fly ash, then removal efficiency is improved, but mechanical abrasion and channel plugging worsen
Solution Approach 1:
The patent replaces mechanical cleaning methods (brushes, scrapers, high-pressure air) with a thermal field-based cleaning system. The heating elements raise the catalyst temperature to evaporate fly ash deposits, converting mechanical cleaning into thermal cleaning. This substitution eliminates mechanical abrasion while maintaining high removal efficiency through phase change of the deposits.
Solution Approach 2:
The patent utilizes phase transitions of fly ash deposits by heating the catalyst to temperatures where the accumulated ash evaporates or decomposes. The thermal energy causes the solid deposits to transition to gas phase, which then flows away with the flue gas, achieving clean removal without mechanical contact that would cause abrasion or plugging.
2Ease of manufacture
If wet chemical regeneration is performed without prior ash removal, then chemical treatment can proceed, but equipment plugging and chemical effectiveness worsen
Solution Approach 1:
The patent implements preliminary thermal cleaning before wet chemical regeneration. By heating the catalyst to evaporate fly ash deposits first, the system prepares the catalyst surface free of particulate obstructions. This preliminary action prevents subsequent equipment plugging during chemical regeneration and ensures chemicals can effectively contact the catalyst surface, maintaining both ease of manufacture and reliability.
3Quantity of substance
If conventional cleaning methods are used, then some fly ash is removed, but catalyst performance loss and operational life reduction worsen
Solution Approach 1:
The patent replaces mechanical cleaning systems with thermal field-based cleaning. Heating elements distributed across the catalyst surface apply thermal energy that evaporates fly ash deposits without mechanical contact. This substitution removes fly ash effectively while preserving catalyst structure and active sites, maintaining catalyst performance and extending operational life.
Solution Approach 2:
The patent enables the catalyst to clean itself through thermal processing. The heating system raises the catalyst temperature to a level where accumulated fly ash spontaneously evaporates or decomposes, and the flue gas flow carries the vaporized deposits away. This self-cleaning mechanism removes fly ash effectively while avoiding external mechanical intervention that would damage the catalyst, preserving performance and extending operational life.
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 method achieves up to 100% removal of fly ash pluggage, maintaining catalyst performance and extending the SCR system's operational life by ensuring channels are open for chemical regeneration processes, while being suitable for in situ and ex situ applications, reducing transportation and cleaning costs.
Implementation Method 1
The particles are accelerated by a pressurized gas stream and directed at the flue gas inlet side of the SCR catalyst
Implementation Method 2
dry ice as particulate blasting medium
Implementation Method 3
The particles are accelerated by a pressurized gas stream and directed at the flue gas inlet side of the SCR catalyst
Data Source
Figure 1A~1B
Figure 2A~2B
Figure 3A
AI summary
The present disclosure relates to methods for treating an SCR catalyst or components of an SCR system having a decreased NOx potential efficiency as a result of particulate pluggage in the system or in one or more channels in the SCR catalyst which renders at least a portion of the catalytic active areas inaccessible for the flue gas. The methods include removal of the particulates and plug(s) using a blasting stream of a pressurized carrier gas having a particulate blasting medium directed at the SCR catalyst or component of an SCR system.