In a groundbreaking development, researchers have unveiled a novel approach to transform industrial waste into valuable products, marking a significant stride in the realm of carbon capture and utilization (CCU). Led by Jhuma Sadhukhan, a distinguished faculty member at the University of Surrey, this innovative study presents a comprehensive life cycle assessment (LCA) of a sustainable CCU system. The system co-produces alcohol ethoxylate (AE7), a crucial component in liquid detergents, and low-medium distillate range liquid fuel, utilizing carbon dioxide from the flue gas of paper and steel industries.
The research, published in the Journal of CO2 Utilization, addresses a critical gap in the literature by developing a novel AE7 production method. Traditionally, AE7 is derived from fossil and marginally bio-based resources. However, this new process harnesses carbon sources from industrial flue gas, offering a more sustainable alternative. The core of this process lies in the Fischer-Tropsch (FT) synthesis, which converts syngas—formed by the reverse-water-gas-shift reaction of recycled CO2 and H2—into valuable products.
The FT synthesis produces C11-C13 alkanes and a light-to-medium fuel co-product. These alkanes are then converted into C12-C14 fatty alcohols through a series of chemical reactions, including dehydrogenation, hydroformylation, and hydrogenation. The fatty alcohols subsequently react with ethylene oxide to form AE7. The yields of AE7 and the fuel co-products vary depending on the source of the flue gas, with the steel industry’s flue gas showing higher yields. Notably, renewable (wind) electricity meets the hydrogen demand and electricity needs for the reactions, totaling 13.4 and 33.3 kWh/kg flue gas, respectively.
The life cycle impact assessment, which includes global warming potential (GWP) and other environmental impacts, reveals significant reductions in GWP for the new systems compared to conventional AE7 production methods. “The new systems have GWP ranging from 0.4–1.3 kg CO2e/kg flue gas (cradle-to-gate) using mass allocation,” Sadhukhan explains. “Considering the GWP reductions due to biogenic CO2 contents, their overall GWP is 2.56 kg CO2e and 10.33 kg CO2e per kg of product (AE7 +fuel) (cradle-to-grave) using economic allocation.”
This research not only highlights the potential for sustainable co-production of high-value surfactants and fuel but also underscores the importance of biogenic CCU in achieving a circular carbon economy. The findings suggest that by leveraging industrial waste and renewable energy, it is possible to create a more sustainable and economically viable pathway for CCU. This could revolutionize the energy sector by providing a scalable solution for reducing carbon emissions while producing valuable chemical products.
The implications of this research are far-reaching. As industries increasingly face pressure to reduce their carbon footprint, the ability to convert flue gas into valuable products offers a compelling solution. The commercial impacts are significant, as companies can potentially offset their emissions while generating additional revenue streams from the co-produced fuel and surfactants. This could lead to a paradigm shift in how industries approach waste management and carbon utilization, paving the way for a more sustainable future.
The study, published in the Journal of CO2 Utilization, provides a robust framework for future developments in the field. By demonstrating the feasibility and benefits of this novel CCU system, the research opens the door to further innovations and applications. As industries continue to seek sustainable solutions, the insights gained from this study will undoubtedly shape future developments in the energy sector, driving progress towards a more circular and low-carbon economy.
