Solid Ammonium Salt Reactor for NOx Purification
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Solution Overview
Problem
Current NOx emission purification systems, particularly those using urea SCR technology, require a massive infrastructure, consume excessive energy, and are complicated due to the need for liquid urea handling and temperature maintenance, while solid urea technologies face issues with thermal decomposition and energy efficiency.
Innovation Solution
A reactor design with two chambers, where the second chamber is a replaceable solid ammonium salt cartridge, allowing for efficient thermal decomposition and ammonia generation, with the ammonia being directed to an ammonia dosing module, reducing energy consumption and simplifying the system by using solid ammonium salt, which has a higher capacity and faster thermal decomposition than liquid urea.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If liquid urea SCR technology is used, then NOx purification efficiency is improved, but system complexity and infrastructure requirements increase
Solution Approach 1:
The patent changes the physical state parameter of the reducing agent from liquid (urea solution) to solid (ammonium carbamate), eliminating the need for liquid handling infrastructure, containers, and injectors while maintaining effective NOx purification through thermal decomposition to ammonia
Solution Approach 2:
The patent extracts and eliminates the complex liquid handling subsystem (containers, injectors, water mixing systems) by using solid ammonium carbamate that can be directly fed into the reactor, keeping only the essential thermal decomposition and catalytic reduction functions
2Device complexity
If solid urea is used, then system complexity is reduced, but thermal decomposition temperature increases energy consumption
Solution Approach 1:
The patent changes the chemical composition parameter from urea to ammonium carbamate, which has a lower thermal decomposition temperature, thereby reducing the energy input required for ammonia generation while maintaining solid-state advantages
3Quantity of substance
If the entire reactor is heated for thermal decomposition, then ammonia generation is sufficient, but energy consumption increases
Solution Approach 1:
The patent segments the reactor into a first chamber for rapid heating and ammonia generation, and a second chamber for storing additional ammonium carbamate, allowing localized heating only where needed rather than heating the entire reactor volume
Solution Approach 2:
The patent pre-loads the second chamber with ammonium carbamate storage capacity, allowing the first chamber to be heated rapidly for immediate ammonia generation while the second chamber serves as a pre-prepared reservoir for sustained operation
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 design enables rapid NOx reduction at initial vehicle driving, decreases energy consumption, and increases the capacity of the NOx emission purification system, allowing for longer driving distances and efficient ammonia regeneration.
Implementation Method 1
the solid ammonium salt such as ammonium carbamate (NH2COONH4), ammonium carbonate ((NH4)2CO3) and so on is thermally decomposed to be ammonia
Implementation Method 2
the ammonia is reacted with NOx in the selective catalytic reduction to be purified into nitrogen harmless to human beings
Data Source
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AI summary
In a reactor for solid ammonium salt, a method of controlling the reactor, and a NOx emission purification system using solid ammonium salt and selective catalytic reduction, the reactor includes a first chamber and a second chamber. The first chamber has an exhaust and a first heating element. Solid ammonium salt is in the first chamber. The second chamber has a second heating element and is formed at a side of the first chamber. The first chamber is connected with the second chamber. Solid ammonium salt is in the second chamber. An amount of the solid ammonium salt in the second chamber is more than that in the first chamber, so that the first chamber is heated and cooled faster than the second chamber.