Two-thirds of the electricity generated in the United States comes from power plants that burn fossil fuels and emit vast quantities of carbon dioxide (CO2). If this greenhouse gas could be captured before it escapes into the air, its effect on the global climate could be mitigated. One popular strategy, known as carbon capture and sequestration (CCS), involves capturing CO2 before it is released and storing it underground. The downside of this method is that CCS requires energy input of its own, known as parasitic energy. This makes it difficult to limit CO2 release without simultaneously increasing the amount of fossil fuel that must be burned, undermining the benefits of capturing carbon in the first place and driving up energy costs. However, recent UC Berkeley research might tip the scales toward a brighter future for carbon capture.
Led by Professor Berend Smit of the Departments of Chemical and Biomolecular Engineering and Chemistry at UC Berkeley, a team of scientists at Cal, Lawrence Berkeley National Laboratory, Rice University and the Electric Power Research Institute has developed a computational method to identify molecules that bind and sequester CO2 more effectively than current technologies, decreasing the amount of parasitic energy required for CCS. This method estimates the ability of specific compounds to capture CO2 and evaluates databases of millions of candidate compounds much more quickly than was previously possible. “Since we can do these calculations so efficiently,” Smit explains, “we can compute the lowest parasitic energy among all possible structures within a class of materials.” Smit’s group identified a number of minerals called zeolites (commonly used in industrial processes) that could reduce the energy diverted to CCS from a power plant’s overall output. Having this ability to predict a particular molecule’s effectiveness at sequestering CO2 will be a powerful tool for making our energy industry cleaner. Ultimately, Smit says, “our biggest hope is for the community to know that we are working on solutions.”