Reducing carbon dioxide (CO2) emissions from power plants is widely considered an essential component of any climate change mitigation plan.
Reducing carbon dioxide (CO2) emissions from power plants is widely considered an essential component of any climate change mitigation plan. Many research efforts focus on developing and deploying carbon capture and sequestration (CCS) systems to keep CO2 emissions from power plants out of the atmosphere. But separating the captured CO2 and converting it back into a gas that can be stored can consume up to 25 percent of a plant’s power-generating capacity. In addition, the CO2 gas is generally injected into underground geological formations for long-term storage — a disposal method whose safety and reliability remain unproven.
A better approach would be to convert the captured CO2 into useful products such as value-added fuels or chemicals. To that end, attention has focused on electrochemical processes — in this case, a process in which chemical reactions release electrical energy, as in the discharge of a battery. The ideal medium in which to conduct electrochemical conversion of CO2 would appear to be water. Water can provide the protons (positively charged particles) needed to make fuels such as methane. But running such “aqueous” (water-based) systems requires large energy inputs, and only a small fraction of the products formed are typically those of interest.
Betar Gallant, an assistant professor of mechanical engineering, and her group at MIT have therefore been focusing on non-aqueous (water-free) electrochemical reactions — in particular, those that occur inside lithium-CO2 batteries.
Read more at Massachusetts Institute of Technology
Photo: MIT Assistant Professor Betar Gallant (left) and graduate student Aliza Khurram are developing a novel battery that could both capture carbon dioxide in power plant exhaust and convert it to a solid ready for safe disposal. CREDIT: Stuart Darsch
