Reformed Ethanol Engine with EGR and Lean NOx Trap
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Internal combustion engine power systems using reformed alcohol fuels face inefficiencies and high emissions, particularly in achieving low nitrogen oxides (NOx) levels and maintaining high exhaust gas temperatures for effective reforming reactions.
Innovation Solution
The process involves using a copper-plated Raney nickel catalyst for ethanol reforming, with exhaust gas recirculation (EGR) and excess air to achieve high efficiency and low emissions, including the use of a lean NOx trap for NOx reduction, and reforming only a portion of the ethanol to optimize engine performance and reduce thermal demands on the reformer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If exhaust gas recirculation is used to reduce NOx emissions, then NOx levels decrease, but exhaust gas temperature decreases which reduces reforming efficiency
Solution Approach 1:
The patent applies parameter changes by precisely controlling the exhaust gas recirculation rate within 5-40% to balance NOx reduction with maintaining sufficient exhaust gas temperature for reforming catalyst activity
Solution Approach 2:
The patent applies local quality by introducing excess air specifically to the reforming reaction zone to locally increase oxygen concentration and maintain high temperature for effective reforming, while other zones maintain EGR for NOx control
2Productivity
If excess air is introduced to maintain high exhaust gas temperature for reforming, then reforming efficiency improves, but oxygen concentration increases leading to higher NOx formation
Solution Approach 1:
The patent applies local quality by introducing excess air specifically to the reforming reaction zone where it is needed for maintaining high temperature and oxygen concentration for effective reforming, while the overall exhaust gas composition is controlled through EGR to limit NOx formation in the combustion chamber
Solution Approach 2:
The patent applies segmentation by separating the air introduction into two distinct zones: excess air to the reforming zone for temperature maintenance, and controlled EGR to the combustion chamber for NOx control, allowing independent optimization of each zone
3Quantity of substance
If ethanol is fully reformed to maximize hydrogen production, then fuel value increases, but thermal demand on the reformer increases
Solution Approach 1:
The patent applies partial action by reforming only a portion of the ethanol fuel rather than fully reforming all ethanol, thereby producing sufficient hydrogen while limiting the thermal energy demand on the reforming system
Solution Approach 2:
The patent applies self-service by using the exhaust gas from the engine combustion chamber to provide the thermal energy needed for the reforming reaction, making the system self-sufficient for its thermal energy requirements
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 enhances engine efficiency, reduces emissions, and maintains high exhaust gas temperatures for effective catalyst activity, achieving low NOx levels and improved fuel value, while minimizing methanation and throttling losses.
Implementation Method 1
contacting a feed gas mixture comprising the ethanol fuel with a reforming catalyst comprising copper in a reforming reaction zone to produce a product reformate gas mixture comprising hydrogen, methane and a carbon oxide component
Implementation Method 2
at least a portion of the discharged exhaust gas mixture is brought into thermal contact with the reforming reaction zone to thereby heat the reforming catalyst therein
Implementation Method 3
A combustible gas mixture is combusted in a combustion chamber of an internal combustion engine to produce an exhaust gas mixture. The energy of combustion is utilized for the generation of mechanical or electrical power
Data Source
AI summary
Improved internal combustion engine power systems (e.g., those used to generate mechanical or electrical power in vehicular applications) that utilize a reformed alcohol fuel comprising a hydrogen-containing gas mixture, and more particularly, the efficient operation of such engines and power systems are disclosed. Modes of operating the engine power systems that provide faster startup and lower cost and emissions are provided. In various preferred embodiments, the internal combustion engine power systems include dilution of the intake fluid mixture introduced into the combustion chamber or cylinder of the engine using recirculated exhaust gas and/or excess combustion air as the diluent, use of blends of ethanol reformate and unreformed ethanol as fuel and aftertreatment of the exhaust gas discharged from the cylinder using a lean NOx trap.