Researchers at the Paul Scherrer Institute PSI and ETH Zurich have investigated the extent to which direct capture of carbon dioxide (CO2) from the ambient air can help to effectively remove greenhouse gases from the atmosphere.
Researchers at the Paul Scherrer Institute PSI and ETH Zurich have investigated the extent to which direct capture of carbon dioxide (CO2) from the ambient air can help to effectively remove greenhouse gases from the atmosphere. The result: With careful planning, for example with regard to location and provision of the necessary energy, CO2 can be removed in a climate-effective manner. The researchers have now published their analysis in the journal Environmental Science & Technology.
Direct air carbon capture and storage (DACCS) is a comparatively new technology for removal of carbon dioxide from the atmosphere. Since it would allow large amounts of CO2 to be, in effect, trapped, this technology could also reduce the greenhouse effect. Researchers at the Paul Scherrer Institute PSI and ETH Zurich have now investigated how effectively this could be implemented with different system configurations of a certain process. To do this, they analysed a total of five different configurations for capturing CO2 from the air and their use at eight different locations around the world. One result: Depending on the combination of technology used and the specific location, CO2 can be removed from the air with an effectiveness of up to 97 percent.
To separate CO2 from the atmosphere, air is first passed over a so-called absorbent with the help of fans. This binds CO2 until its capacity to absorb the greenhouse gas is exhausted. Then, in the second, so-called desorption step, the CO2 is released from the absorbent again. Depending on the absorbent, this happens at comparatively high temperatures of up to 900 degrees Celsius or at rather low temperatures of about 100 degrees Celsius. In addition to the energy required for the production and installation of the equipment, the operation of the fans and generation of the required heat produce greenhouse gas emissions. "The use of this technology only makes sense if these emissions are significantly lower than the amounts of CO2 it helps to store," says Tom Terlouw, who conducts research at PSI's Laboratory for Energy Systems Analysis and is first author of the study.
Read more at: Paul Scherrer Institute
