On-Board Ammonia Cracking for Hydrogen Fuel via Exhaust Heat
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for generating hydrogen on-board vehicles face challenges such as inefficient ammonia cracking due to limited electrical supply, inconsistent combustion of ammonia in internal combustion engines, and safety issues with storing hydrogen as a light, low-density gas.
Innovation Solution
A system comprising an internal combustion engine, heat exchange catalyst units, electric catalyst units, and plate heat exchange units that work in series to crack ammonia into hydrogen, utilizing exhaust gas heat and electrical heating to facilitate ammonia cracking, and manage hydrogen storage and fueling efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If ammonia is used as fuel in internal combustion engines, then CO2 emissions are eliminated, but combustion consistency deteriorates due to slow flame propagation speed
Solution Approach 1:
The patent introduces hydrogen as an intermediary substance that bridges the gap between ammonia storage and combustion. Ammonia is cracked into hydrogen and nitrogen, and the hydrogen serves as the actual combustion fuel while ammonia remains the storage medium. This resolves the contradiction by eliminating CO2 emissions through ammonia decomposition while ensuring reliable combustion through hydrogen's fast flame propagation characteristics.
Solution Approach 2:
The patent changes the chemical composition parameter of the fuel by converting ammonia (NH3) into hydrogen (H2) through catalytic cracking. This parameter change transforms the fuel from a substance with slow combustion (ammonia) to one with fast combustion (hydrogen), while maintaining the zero CO2 emission benefit.
2Quantity of substance
If hydrogen is stored on-board vehicles, then fuel availability is improved, but safety deteriorates due to hydrogen's light and low-density properties
Solution Approach 1:
The patent implements self-service by using the vehicle's own exhaust heat to drive the ammonia cracking process. The heat exchange catalyst unit captures thermal energy from exhaust gases and uses it to decompose ammonia into hydrogen, eliminating the need for external heating systems and reducing overall system complexity while maintaining safety.
Solution Approach 2:
The patent uses ammonia as an intermediary storage medium that converts to hydrogen only when needed. Ammonia's liquid state at moderate pressures provides safe storage, while the catalytic cracking process converts it to hydrogen for combustion. This intermediary approach avoids storing large quantities of gaseous hydrogen directly, reducing safety risks.
3Productivity
If electrical heating is used for ammonia cracking, then cracking efficiency is improved, but energy consumption increases beyond available electrical supply
Solution Approach 1:
The patent introduces exhaust heat as an intermediary energy source that mediates between the available thermal energy in exhaust gases and the energy required for ammonia cracking. The heat exchange catalyst unit transfers thermal energy from exhaust gases to the ammonia feed, enabling efficient cracking without drawing excessive electrical power.
Solution Approach 2:
The patent changes the energy source parameter from electrical heating to thermal heating using exhaust gases. This parameter change allows the system to utilize waste heat that would otherwise be lost, improving cracking efficiency while staying within the constraints of available electrical supply for catalyst 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
Enables efficient on-board hydrogen production from ammonia, addressing combustion and storage challenges, and providing a reliable fuel source for internal combustion engines while minimizing environmental impact.
Implementation Method 1
heat exchange catalyst units, electric catalyst units, and plate heat exchange units that work in series to crack ammonia into hydrogen, utilizing exhaust gas heat
Implementation Method 2
electric catalyst units... that work in series to crack ammonia into hydrogen, utilizing exhaust gas heat and electrical heating
Implementation Method 3
heat exchange catalyst units, electric catalyst units... to crack ammonia into hydrogen
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 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.