Vaibhav Bahadur, associate professor in the Walker Department of Mechanical Engineering, has authored a newly published paper in Applied Energy that outlines a new method for carbon capture sequestration and storage without the need for costly carbon transportation. We’ve asked him to detail this new research below.
Q: Can you give us an overview of the research outlined in this new paper?
VB: This paper analyzes an integrated carbon-capture sequestration (CCS) system involving co-located capture as well as storage of carbon dioxide (from oceanwater). Conventionally, CO2 is first captured (from industries, power plants or from air), then transported to the sequestration site, and finally sequestered by pumping into underground reservoirs. In contrast, this study proposes carbon capture from oceanwater and co-located storage as CO2 hydrates under the seabed. This technology can be conveniently deployed using existing offshore platforms. Importantly, our concept eliminates the need for CO2 transportation, which is challenging and expensive. Hydrates-based sequestration (with sealing) is a safe method for long-term storage, as the conditions at the bottom of the seafloor are thermodynamically favorable for hydrates. This study quantifies the key technical and techno-economic parameters associated with this technology. It is seen that the cost and energy requirements for oceanwater capture are significantly higher than that for sequestration. This study outlines pathways for cost reduction, which is essential to make such technologies viable in the real world.
Q: What are the benefits of using decommissioned offshore platforms for carbon capture?
VVB: While offshore platforms have contributed greatly to meeting the world’s energy supply, they will eventually not be needed in a renewables-powered economy. Technologies like the one proposed in this study allow the repurposing of trillions of dollars of offshore infrastructure to address climate-related challenges. These platforms can house all the equipment need for CO2 capture from oceanwater and conversion to CO2 hydrates (for sequestration). Many deepwater platforms are in locations where the seabed is deep enough for CO2 hydrates to remain stable. Another big advantage of offshore platforms is that they eliminate the need to transport CO2 from land-based facilities to the sequestration location.
Q: How will this aid in the global transition to renewable energy and why is that important?
VB: Greater penetration of renewables is key to fighting climate change. At the same time, it is being widely recognized that the pace of renewables adoption is not going to be enough to avoid the worst effects of climate change. Accordingly, it will be critical to intervene with CCS technologies to remove CO2 from the air and oceans. This study presents a new technological concept in the CCS space, and targets the same objectives that the transition to renewables serves to achieve.
