In a significant stride towards cleaner energy solutions, researchers have demonstrated the potential of a novel technology that could revolutionize the way we capture carbon dioxide from biomass combustion. The study, led by Alberto Abad from the Instituto de Carboquímica (ICB-CSIC) in Zaragoza, Spain, explores the use of Chemical Looping Combustion (CLC) with olive stone, a type of biomass, and has been published in the journal “Applications in Energy and Combustion Science.”
Chemical Looping Combustion is an innovative process that splits the combustion of fuel into two separate reactors: the fuel reactor, where the fuel is combusted and CO2 is concentrated, and the air reactor, where the oxygen carrier is regenerated. This inherent separation of CO2 from air makes CLC a promising technology for Bioenergy with CO2 Capture and Storage (BECCS), a concept that has the potential for carbon dioxide removal from the atmosphere.
The research team conducted tests at a 20 kWth scale using a highly reactive iron ore as the oxygen carrier. They analyzed the effects of various operating conditions, such as reacting temperature, oxygen carrier-to-fuel ratio, and specific solids inventory, on combustion efficiency and CO2 capture. Additionally, tests at a lower scale (6 kWth) evaluated the impact of some design parameters.
“One of the key findings of our study is the cross-effect between CO2 capture and combustion efficiency,” Abad explained. “As CO2 capture increased, the combustion efficiency decreased due to higher char conversion. However, we found that CO2 capture values above 90% may be feasible with oxygen demand values around 15% when operating at fuel reactor temperatures above 950 °C and specific solids inventory values about 300-400 kg/MWth.”
The study also revealed that full combustion was not achieved due to the high volatile content of the biomass and the uncompleted oxidation of char gasification products. However, the combustion degree improved at the higher scale due to the proper development of the characteristic fluid dynamic of a circulating fluidized bed.
This research holds significant implications for the energy sector. As the world seeks to reduce greenhouse gas emissions and transition to cleaner energy sources, technologies like CLC with CO2 capture can play a crucial role. The use of biomass, such as olive stone, not only provides a renewable energy source but also contributes to carbon dioxide removal from the atmosphere.
The findings of this study could pave the way for future developments in the field of bioenergy and CO2 capture. As Alberto Abad noted, “Our results demonstrate the potential of CLC technology for efficient and economical CO2 capture from biomass combustion. This could be a game-changer in the quest for cleaner energy solutions.”
With further research and development, CLC technology could become a key player in the global effort to mitigate climate change and achieve a sustainable energy future. The study published in “Applications in Energy and Combustion Science” marks a significant step forward in this exciting and rapidly evolving field.