Researchers from the Paul Scherrer Institute (PSI) and ETH Zurich investigated the effectiveness of direct air carbon capture and storage (DACCS) in the battle against climate change. DACCS is a relatively new technology and it would allow large amounts of carbon dioxide to be trapped, overall reducing the greenhouse effect. The analysis considered five configurations for capturing CO2 from the air at eight locations around the world.
The research focused on a system called Climeworks, a low temperature process created by a Swiss company, operating in Chile, Greece, Jordan, Mexico, Spain, Iceland, Norway and Switzerland. At each location the team calculated the overall greenhouse gas emissions over a plant’s lifecycle and drew up five site-specific system layouts for atmospheric CO2 capture.
In the DACCS process, air is pushed over an absorbent layer by fans; CO2 binds to the layer until it reaches its capacity to absorb greenhouse gasses. During the desorption step, CO2 is released from the absorbent layer and, depending on the given absorbent material, this process either happens at high temperatures of 900° C or low temperatures of 100° C. Researchers found that the energy required for the production and installation of this equipment, fan operation and generation of required heat is large and produces greenhouse gas emissions, which is working against the ultimate goal of DACCS.
Christian Bauer, scientist in the Laboratory for Energy Systems Analysis at PSI. Source: PSI/Mahir Dzambegovic
The results proved that CO2 capture tech is just a complementary process to overall decarbonization and cannot be the only system applied for this purpose. While it is not the standalone solution to climate change, the team notes that it could be very helpful in achieving the goals laid out in the Paris Climate Agreement. Net-zero carbon emissions could be achieved with the help of negative emissions technology and DACCS.
The study was published in Environmental Science and Technology.
