Fuel Cell Anode Exhaust CO2 Separation via Waste Heat Chiller
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for separating carbon dioxide from the anode exhaust in fuel cell systems are not cost-effective, as they result in significant energy loss and do not efficiently recover heat or separate hydrogen, methane, and carbon monoxide from the anode exhaust.
Innovation Solution
An integrated power production system that includes a fuel cell with a gas separation assembly, utilizing a chiller to liquefy carbon dioxide from the anode exhaust and a gas separation device to separate it from residual fuel gases, while recovering waste heat to drive the chiller and oxidize residual fuel gases to heat the flue gas, thereby enhancing the efficiency of carbon dioxide separation and recovery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If carbon dioxide capture systems are applied to separate carbon dioxide from post-combustion flue gas, then carbon dioxide separation is achieved, but significant energy loss occurs resulting in high costs
Solution Approach 1:
The patent combines the carbon dioxide capture process with power generation by integrating a fuel cell system. The anode exhaust gas from the fuel cell, which is enriched with carbon dioxide, is directly utilized for power generation in a turbine or engine, merging the separation and energy recovery processes into a single integrated system that eliminates energy loss.
Solution Approach 2:
The patent changes the operational parameters of the fuel cell system to optimize carbon dioxide enrichment in the anode exhaust. By adjusting the fuel composition, operating temperature, and air-to-fuel ratio, the system achieves high carbon dioxide concentration in the exhaust stream, enabling effective separation without energy-intensive processes.
2Measurement precision
If external reforming fuel cell systems are used, then carbon dioxide transfer from cathode to anode is achieved, but substantial amounts of hydrogen, carbon monoxide, and methane remain in the anode exhaust requiring additional purification
Solution Approach 1:
The patent extracts and utilizes the residual fuel gases (hydrogen, carbon monoxide, and methane) from the anode exhaust instead of removing them as impurities. These gases are fed to a turbine or engine for power generation, converting what would be purification requirements into additional energy production opportunities.
Solution Approach 2:
The anode exhaust gas serves multiple functions: it is used for power generation in the turbine/engine, and the residual fuel gases are simultaneously utilized as fuel for this power generation process. This multi-functional approach eliminates the need for separate purification systems.
3Measurement precision
If internal reforming carbonate fuel cells are used, then methane amount in anode exhaust is reduced to negligible levels, but substantial amounts of hydrogen, carbon monoxide and water impurities remain requiring processing
Solution Approach 1:
The patent converts the harmful impurities (hydrogen, carbon monoxide, and water) in the anode exhaust into beneficial resources. These gases are utilized as fuel for power generation in the turbine or engine, transforming what would require energy-intensive processing into a source of additional energy production.
4Measurement precision
If anode exhaust is subjected to processing for carbon dioxide capture, then carbon dioxide separation is achieved, but heat and useful gases in the flue gas are not recovered
Solution Approach 1:
The patent performs preliminary action by directly utilizing the anode exhaust gas for power generation before any separation or processing occurs. The exhaust gas is fed to the turbine or engine, recovering both heat and useful gases simultaneously, eliminating the need for subsequent processing steps that would otherwise be required.
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 system achieves efficient separation of high-purity carbon dioxide from the anode exhaust, reducing energy losses and enabling the recovery of waste heat, resulting in a more cost-effective and efficient method for carbon dioxide capture and utilization in other industries.
Implementation Method 1
a chiller assembly configured to cool the anode exhaust to a predetermined temperature so as to liquefy carbon dioxide in the anode exhaust
Implementation Method 2
the electrochemical reaction in the fuel cell then results in the carbon dioxide in the feed gas being transferred from the cathode to the anode of the fuel cell
Implementation Method 3
an oxidizer configured to receive the residual fuel gas separated by the gas separation device, receive temperature adjusted flue gas from the first heat exchanger, oxidize the residual fuel gas to heat flue gas
Implementation Method 4
a first heat exchanger configured to receive the flue gas output from the flue gas generating assembly, and adjust a temperature of the flue gas to be in a range of 500-650°C
Data Source
Figure 1A
Figure 1B
Figure 2
AI summary
A power producing system is configured to utilize a flue gas output from a flue gas generating assembly, where the flue gas includes carbon dioxide and oxygen. The power producing system includes a fuel cell comprising an anode section and a cathode section, where the cathode section is configured to receive inlet oxidant gas that contains the flue gas output from the flue gas generating assembly. The power producing system also includes a gas separation assembly that is configured to receive anode exhaust output from the anode section of the fuel cell and comprising a chiller assembly configured to cool the anode exhaust to a predetermined temperature so as to liquefy carbon dioxide in the anode exhaust. The fuel cell and the chiller assembly are configured such that waste heat produced by the fuel cell is utilized to drive the chiller assembly.