Flameless Steam Reformer Design for SOFC Hydrogen Production
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing reformers for solid oxide fuel cells face challenges such as carbon deposition, catalyst inactivation, thermal stress, and the need for complex and large reactors due to flame-based heat transfer, making them unsuitable for small-scale and efficient hydrogen production.
Innovation Solution
A flameless steam reformer design with a main housing, catalyst housing, and passage housing, where combustion and reforming catalysts are separated, and combustion fuel is preheated by a combustion catalyst at a low temperature, eliminating the need for a burner and optimizing heat transfer without flame-induced hot spots.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a flame-based burner is used for heating in the reformer, then high temperature heating is achieved, but hot spots occur on the inner wall causing thermal stress and reduced durability
Solution Approach 1:
The patent extracts and eliminates the flame source (burner) from the reformer system. By using an external heater to heat the reformer body and a separate combustion catalyst for fuel preheating, the design removes the direct flame contact that causes hot spots and thermal stress on the inner wall, thereby improving durability while maintaining heating effectiveness
Solution Approach 2:
The patent introduces an intermediary approach by using a combustion catalyst in a separate preheating chamber rather than direct flame heating. The combustion catalyst acts as an intermediary that heats the combustion fuel without creating direct flame contact with the reformer walls, thus avoiding hot spots while achieving the necessary temperature for fuel preheating
2Productivity
If steam reforming reaction occurs rapidly to produce hydrogen efficiently, then hydrogen production efficiency increases, but severe temperature drop occurs locally deteriorating fuel cell performance
Solution Approach 1:
The patent segments the reforming process into two separate chambers: a combustion catalyst chamber for fuel preheating and a reforming catalyst chamber for hydrogen production. This segmentation allows the endothermic steam reforming reaction to occur in a controlled environment where heat is supplied through the reformer body wall, preventing severe local temperature drops that would occur with direct flame heating while maintaining high hydrogen production efficiency
3Loss of substance
If a complex hydrocarbon is decomposed to produce hydrogen, then pure hydrogen can be obtained, but carbon is continuously deposited reducing catalyst activity and blocking gas passage
Solution Approach 1:
The patent uses a two-stage process where the combustion catalyst first partially oxidizes the hydrocarbon fuel to produce a mixture of CO and H2, which then undergoes steam reforming in the second chamber. This copying approach avoids direct decomposition of complex hydrocarbons that leads to carbon deposition, while still achieving high hydrogen purity through the controlled two-stage reaction process
Solution Approach 2:
The patent changes the reaction parameters by using controlled partial oxidation followed by steam reforming instead of direct decomposition. By adjusting the oxygen-to-fuel ratio in the combustion catalyst chamber to achieve partial oxidation rather than complete combustion or decomposition, the system prevents carbon deposition while maintaining catalyst activity and producing high-purity hydrogen
4Productivity
If the reformer is designed for large-scale hydrogen production with additional burner and complex structure, then steam reforming efficiency is achieved, but the reactor becomes large and complex with long starting time
Solution Approach 1:
The patent merges the heating function and fuel preheating function into a single integrated reformer body. The external heater heats the reformer body which in turn heats the combustion fuel through the combustion catalyst, eliminating the need for a separate burner and reducing structural complexity while maintaining efficient steam reforming for hydrogen production
Solution Approach 2:
The patent implements preliminary action by preheating the combustion fuel in the combustion catalyst chamber before it reaches the reforming catalyst chamber. This preheating occurs through heat transfer from the externally heated reformer body, preparing the fuel for efficient steam reforming while reducing the overall starting time and simplifying the reactor structure compared to systems requiring separate burners
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
The flameless steam reformer achieves high efficiency, fast start-up, reduced heat loss, and improved durability by preheating combustion fuel and reforming air at low temperatures, producing high-quality hydrogen with a compact and easily maintainable structure.
Implementation Method 1
a combustion catalyst and a reforming catalyst are provided in the catalyst housing, and the combustion fuel is preheated by the combustion catalyst to a given temperature
Implementation Method 2
the reforming catalyst reacts the combustion fuel and water with each other to reform the combustion fuel into hydrogen and carbon monoxide
Implementation Method 3
combustion fuel is preheated by a combustion catalyst at a low temperature, eliminating the need for a burner and optimizing heat transfer without flame-induced hot spots
Data Source
AI summary
A flameless steam reformer is provided, which includes a main housing, a catalyst housing which is inserted to the main housing and in which a combustion catalyst and a reforming catalyst are provided such that they are partitioned from each other, and a passage housing which is disposed between the main housing and the catalyst housing and includes a passage through which a reforming fuel supplied to the catalyst housing moves.