Exhaust Pipe Catalyst for Autothermal Hydrogen Generation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for generating hydrogen on board vehicles are bulky and inefficient, requiring external heating sources and additional purification steps to reduce contaminants in the hydrogen gas stream.
Innovation Solution
A compact apparatus using a catalyst integrated into an exhaust pipe system of internal combustion engines, where hydrocarbons are converted into hydrogen and carbon monoxide using autothermal steam reforming and catalytic partial oxidation, leveraging existing exhaust gas heat and water content to reduce soot formation and eliminate the need for external ignition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional steam reforming process is used to generate hydrogen, then hydrogen can be produced, but the apparatus becomes bulky and requires external heating sources and additional purification steps
Solution Approach 1:
The patent combines the steam reforming process and catalytic partial oxidation into a single integrated reactor system. The reforming catalyst serves dual functions: facilitating steam reforming of hydrocarbons and catalyzing partial oxidation of CO and unburned hydrocarbons. This merging eliminates the need for separate purification steps and external heating sources, reducing apparatus complexity while maintaining hydrogen production efficiency.
Solution Approach 2:
The reforming catalyst is designed to perform multiple functions simultaneously: (1) catalyze steam reforming reactions to produce hydrogen, (2) oxidize carbon monoxide to carbon dioxide, and (3) oxidize unburned hydrocarbons. This multi-functionality replaces what would traditionally require separate catalysts and processing units, significantly simplifying the overall system architecture.
2Temperature
If autothermal reforming with external ignition is used, then reforming temperature can be achieved, but the apparatus becomes more elaborate with additional ignition mechanisms
Solution Approach 1:
The system uses the engine's own exhaust gas as the heating source for the reforming process. The hot exhaust gases (typically 400-600°C from diesel engines) pass through the reforming catalyst, providing the necessary heat for steam reforming reactions. This self-service approach eliminates the need for external burners, ignition systems, or separate heating devices, thereby simplifying the apparatus while achieving required reforming temperatures.
3Quantity of substance
If conventional reforming processes are used, then hydrogen is produced, but carbon monoxide contamination requires additional purification steps
Solution Approach 1:
The reforming catalyst acts as an intermediary that simultaneously produces hydrogen through steam reforming and removes carbon monoxide through catalytic oxidation. The catalyst surface provides active sites for both the reforming reaction (producing H2) and the oxidation reaction (converting CO to CO2). This dual action occurs in the same reactor without requiring separate purification units, simplifying the overall system while ensuring hydrogen quality.
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 solution enables efficient, compact, and self-sustaining hydrogen generation for vehicle use, reducing soot formation and eliminating the need for external heating, with the generated hydrogen and carbon monoxide being more reactive for regenerating catalysts and fuel cells.
Implementation Method 1
A first exhaust gas stream is conducted over a reforming catalyst after hydrocarbons have been added to the exhaust stream
Implementation Method 2
steam is added to the fuel and this mixture is converted in what is referred to as a steam reforming process into hydrogen and carbon monoxide
Implementation Method 3
the reforming process can be conducted auto thermally by adding a certain amount of oxygen to the mixture of steam and fuel such that first heat is generated by catalytic partial oxidation (CPO) of the fuel
Implementation Method 4
the reforming process can be conducted auto thermally by adding a certain amount of oxygen to the mixture of steam and fuel such that first heat is generated by catalytic partial oxidation (CPO) of the fuel
Implementation Method 5
leveraging existing exhaust gas heat and water content to reduce soot formation
Data Source
AI summary
The present invention relates to the catalytic conversion of hydrocarbons for generating a gas that is rich in hydrogen, to the use of said apparatus and to a process for generating hydrogen. The apparatus comprises a reforming catalyst (5), as well as a means (8) for supplying hydrocarbons to the catalyst. The reforming catalyst is arranged in an exhaust pipe (3) through which the exhaust gases of combustion processes are passed.