December 13, 2017
New Study Finds Carbon Capture and Utilization Won't Mitigate Global Warming
By Amanda KingMedia Inquiries
- Wilton E. Scott Institute for Energy Innovation
A study by four international scientists, including Carnegie Mellon University's Edward S. Rubin, questions the effectiveness of a proposed plan to mitigate global warming by using carbon dioxide (CO2) to produce fuels for transportation.
The approach, called carbon capture and utilization (CCU), would collect CO2 emitted by a power plant or industrial process and convert it to a liquid fuel using existing chemical technologies. CCU is being promoted by a number of researchers and organizations as a way to reduce the extraction of fossil fuels while also reducing CO2 emissions linked to climate change.
The new study published in the journal Energy & Environmental Science finds that CCU has little potential to mitigate climate change and could actually worsen the problem — unless the large amount of energy needed to manufacture the fuel comes from carbon-free sources, such as wind and solar.
"For that reason, proponents of CCU assume that all the energy needed is supplied by renewable energy," said Rubin, a co-author of the study.
Rubin and J. Carlos Abanades of the Spanish National Research Council, Marco Mazzotti of ETH Zurich and Howard J. Herzog of the MIT Energy Initiative presented their findings in a paper titled "On the climate change mitigation potential of CO2 conversion to fuels."
Rubin, the Alumni Chair Professor of Environmental Engineering and Science in Carnegie Mellon's Department of Engineering and Public Policy, and co-authors find that a far more effective approach to manufacturing transportation fuels is to use that renewable energy to decarbonize the electric power grid, while sequestering the CO2 from fossil fuel use deep underground.
"The result is a system that avoids far greater emissions of greenhouse gases, reduces the overall extraction of fossil fuel resources, and is less costly than a CO2 utilization scheme producing the same amount of fuel," said Rubin.
The researchers said they believe that while large-scale CO2 utilization sounds attractive, their analysis "shows that this concept has severe limitations as a mitigation measure or cost-effective strategy for reducing CO2 emissions."