Researchers at the University of Sheffield have made significant strides in understanding and modeling combustion processes under supercritical carbon dioxide (sCO2) conditions, a development that could greatly enhance the efficiency of next-generation power plants.
The team, led by James M. Harman-Thomas, Kevin J. Hughes, and Mohamed Pourkashanian, focused their efforts on direct-fired sCO2 power cycles, which offer a promising avenue for burning gaseous fuels with inherent carbon capture. Unlike traditional carbon capture and storage (CCS) methods, which can significantly reduce the efficiency of power plants, the direct-fired sCO2 approach allows for efficiencies comparable to conventional fossil fuel power plants.
The challenge lies in the fact that at high pressures and large dilutions of CO2, the combustion mechanisms are not well understood. To address this, the researchers employed sensitivity and quantitative analysis of four established chemical kinetic mechanisms. Their goal was to identify the most important reactions and the best-performing mechanisms over a range of conditions.
Their findings revealed that CH3O2 chemistry plays a pivotal role in modeling methane combustion above 200 atm. More importantly, the team developed the University of Sheffield (UoS) sCO2 mechanism, which better models the ignition delay time (IDT) of high-pressure combustion in a large dilution of CO2. Quantitative analysis showed that the UoS sCO2 mechanism was the best fit to the greatest number of IDT datasets and had the lowest average absolute error value, indicating superior performance compared to the four existing chemical kinetic mechanisms, which are well-validated for lower pressure conditions.
The practical applications of this research are substantial for the energy sector. By improving the understanding and modeling of combustion in sCO2 conditions, the researchers are paving the way for more efficient and cleaner power generation. This could lead to the development of advanced power plants that not only achieve high efficiencies but also inherently capture carbon, significantly reducing greenhouse gas emissions.
The work conducted by the University of Sheffield team represents a critical step forward in the quest for sustainable and efficient energy solutions, offering a beacon of hope for a future where power generation is both clean and economical.
This article is based on research available at arXiv.