Ionizer-Controlled Selective Catalytic Converter for NOx Reduction
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Solution Overview
Problem
Existing exhaust treatment systems, including selective catalytic converters, are ineffective at reducing NOx emissions when the catalyst temperature is below its lightoff temperature, leading to undesirable constituents like NOx being released into the environment.
Innovation Solution
A method and system that activate an exhaust ionizer only when the catalyst temperature of a selective catalytic converter is at or above its effective temperature, using a controller to monitor temperature data from sensors and deactivate the ionizer when the temperature is below the lightoff temperature to optimize NOx reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the exhaust ionizer is activated to facilitate collection of particulate matter, then particulate matter collection is improved, but NOx emissions increase
Solution Approach 1:
The exhaust ionizer is dynamically controlled based on real-time catalyst temperature monitoring. The controller activates the ionizer only when the catalyst temperature is at or above the lightoff temperature, and deactivates it when the temperature falls below this threshold. This dynamic operation resolves the contradiction by enabling particulate collection only under conditions where NOx will be effectively treated.
Solution Approach 2:
The system implements feedback control through temperature sensors that continuously monitor catalyst temperature and provide signals to the controller. The controller uses this feedback to determine whether to activate or deactivate the exhaust ionizer, ensuring that ionizer operation is synchronized with catalyst effectiveness, thereby preventing NOx emissions while maintaining particulate collection.
2Use of energy by moving object
If the selective catalytic converter operates below lightoff temperature, then energy consumption is reduced, but NOx reduction effectiveness deteriorates
Solution Approach 1:
The system performs preliminary action by pre-heating the catalyst or maintaining it above lightoff temperature through other means before activating the exhaust ionizer. This ensures that when the ionizer is activated for particulate collection, the catalyst is already in a state capable of effectively reducing NOx, thus avoiding the energy consumption trap of operating below lightoff temperature.
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
This approach ensures the selective catalytic converter operates effectively above its lightoff temperature, reducing NOx emissions and other pollutants like carbon monoxide and particulate matter, thereby improving environmental safety by synchronizing ionizer operation with catalyst temperature.
Implementation Method 1
exhaust gas can be ionized with a suitable exhaust ionizer, such as a corona discharge device or plasma reactor
Implementation Method 2
exhaust gas can be ionized with a suitable exhaust ionizer, such as a corona discharge device or plasma reactor
Implementation Method 3
a selective catalytic converter including an ammonia catalyst can reduce NOx to N2 and water
Implementation Method 4
The primary catalytic converter is configured to at least oxidize carbon monoxide
Implementation Method 5
a particle collection device, and is charged opposite to a charge applied to exhaust by the exhaust ionizer
Data Source
AI summary
A method for treating exhaust from an engine. The method includes activating an exhaust ionizer in receipt of the exhaust when temperature of a catalyst of a selective catalytic converter, which is in communication with the exhaust ionizer so as to receive exhaust from the exhaust ionizer, is equal to or above an effective temperature. The method further includes deactivating or maintaining the exhaust ionizer in a deactivated state when temperature of the catalyst is below the effective temperature.