Closing the Carbon Cycle

Closing the Carbon Cycle

An illustration of key points in the carbon cycle. (NASA Earth Observatory)

An illustration of key points in the carbon cycle. (NASA Earth Observatory)

One area of Peter Eisenberger’s work is studying the carbon cycle and finding ways to capture excess carbon-dioxide from the atmosphere and put it to work.

Most life on Earth has a carbon cycle that is roughly in balance with the atmospheric content as it slowly changes over time. Humans, however, have been extracting carbon that had been stored for millennia in the land and under the oceans, and we have been burning these fossil fuels for energy in an open cycle that puts stored carbon into the atmosphere, increasing the greenhouse gas effect and creating the risk of catastrophic climate change.

Our research is directed at how to close this carbon cycle and meet our needs for energy security and economic development, while at the same time avoiding the risk of catastrophic climate change. In the long-run, sustainable development requires a shift to renewable energy sources. In the short-run, it requires swift action to remove accumulating CO2 from the atmosphere and a shift to negative carbon production.

One way to get to negative CO2 emissions is to capture CO2 from the ambient air. We are developing ways to mimic nature by using CO2 to make synthetic liquid fuels that are carbon neutral. These synthetic liquid fuels are made from ambient CO2 and hydrogen from water; when combusted, they release CO2 and water vapor. Captured CO2 can also be stored, as nature stores carbon, in ways that help meet our structural needs by converting it to plastics or cement or storing it in geological sites. We have found that utilizing moisture-assisted desorption to recover adsorbed CO2 at relatively low temperatures or tailored immobilized amine sorbents also have the potential to reduce costs by using low-grade process heat. These processes could allow economy to become carbon neutral in the short-term while enabling a gradual shift to renewable energy sources for the future.  —Peter Eisenberger    

Carbon dioxide emissions pathways to 2100 for two IPCC scenarios. The "domain of optimism" represents what could be achieved by future technology efficiency gains and a substantial shift to emission-less energy. (Eisenberger et al., 2009)

This chart shows carbon dioxide emissions pathways to 2100 for two IPCC scenarios. The “domain of optimism” represents what could be achieved by future technology efficiency gains and a substantial shift to emission-less energy. (Eisenberger et al., 2009)