On-Board Ammonia Cracking for Engine Fueling Without Fossil Promoters
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Solution Overview
Problem
Existing internal combustion engines face challenges in using ammonia as fuel due to inefficient combustion and the need for secondary combustion promoters, and hydrogen storage poses safety issues, while electrified vehicles have environmental concerns.
Innovation Solution
A system for on-board ammonia cracking using a heat exchange catalyst unit and an electric catalyst unit to produce hydrogen from ammonia without fossil fuel promoters, utilizing exhaust gas heat and vehicle power for cracking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If pure ammonia is used as fuel in internal combustion engines, then zero carbon dioxide emissions are achieved, but combustion is too slow to complete during the power stroke at high engine speeds
Solution Approach 1:
The system segments the fuel supply into two components: ammonia (for zero emissions) and a small amount of fossil fuel promoter (for rapid combustion initiation). This segmentation allows each component to fulfill its specific role - ammonia provides the clean fuel base while the promoter ensures adequate combustion speed.
Solution Approach 2:
A fossil fuel promoter acts as an intermediary substance that facilitates the combustion of ammonia. The promoter ignites first and creates conditions that enable ammonia to combust at sufficient speeds, bridging the gap between ammonia's clean properties and the engine's combustion speed requirements.
2Speed
If a secondary combustion promoter fuel is used to enable ammonia combustion, then adequate combustion rate is achieved, but the system requires additional control mechanisms and fossil fuel infrastructure
Solution Approach 1:
The system changes the concentration parameter of the fossil fuel promoter to be minimal (just enough to initiate combustion) rather than using it as a primary fuel. This parameter change reduces the need for complex control mechanisms while maintaining adequate combustion rates.
Solution Approach 2:
The fossil fuel promoter is used in such small, controlled amounts that it acts as a temporary ignition aid rather than a sustained fuel source. This disposable-like usage minimizes the need for complex storage and control infrastructure.
3Object-generated harmful factors
If hydrogen is stored on-board for fueling internal combustion engines, then zero-emission fuel is available, but safety issues arise from hydrogen storage
Solution Approach 1:
The system replaces the mechanical storage approach (hydrogen tanks) with a chemical storage approach (ammonia). Ammonia stores hydrogen in a stable, liquid form at ambient conditions, eliminating the safety issues associated with high-pressure hydrogen storage while maintaining zero-emission capabilities.
Solution Approach 2:
The system utilizes the phase transition of ammonia from liquid (safe storage form) to gas (combustion form) on-demand. This phase transition allows safe liquid storage while providing gaseous fuel when needed, resolving the safety contradiction.
4Object-generated harmful factors
If electrified vehicles are used to reduce emissions, then fewer global warming emissions are produced, but environmental and human rights concerns arise from mining raw materials
Solution Approach 1:
The system uses ammonia, which can be produced from atmospheric nitrogen and water through the Haber process, eliminating dependence on mined materials. The fuel system is self-sufficient, using readily available resources rather than requiring environmentally damaging mining operations for batteries and rare earth elements.
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
Provides a zero-emission fuel source for internal combustion engines by cracking ammonia into hydrogen, eliminating the need for fossil fuels and addressing storage safety issues.
Implementation Method 1
a heat exchange catalyst unit fluidly coupled to the ammonia tank having an exhaust gas inlet, an exhaust gas outlet, an ammonia inlet, and a hydrogen outlet, wherein the heat exchange catalyst unit receives exhaust gas from the internal combustion engine via the exhaust gas inlet
Implementation Method 2
the gaseous ammonia undergoes a cracking process in the heat exchange catalyst unit if the exhaust gas has reached a temperature sufficient to perform ammonia cracking
Implementation Method 3
an electric catalyst unit fluidly coupled in series to the heat exchange catalyst unit via only the hydrogen outlet, wherein gaseous ammonia flows from the ammonia tank to the ammonia inlet upon vaporization of the liquid ammonia, wherein the gaseous ammonia undergoes a cracking process in the heat exchange catalyst unit if the exhaust gas has reached a temperature sufficient to perform ammonia cracking
Implementation Method 4
the heat exchange catalyst unit includes a plate heat exchanger
Data Source
AI summary
The present invention relates, in general, to systems and methods for generating hydrogen from ammonia on-board vehicles, where the produced hydrogen is used as fuel source for an internal combustion engine. The present invention utilizes an electric catalyst unit operating in series with a plate-type heat exchange catalyst unit. The electric catalyst unit is used to initiate an ammonia cracking process on-board during a cold start or low load operating condition of the internal combustion engine, where the ammonia cracking process occurs in the heat exchange catalyst unit once exhaust gas from the internal combustion engine has been heated to a threshold temperature suitable to perform the ammonia cracking process.