Transdisciplinary analysis and Life Cycle Assessment on CO2 Direct Air Capture using cryogenic technology

Details

Supervisors

Luis Alconero, Patricia

Faculty

Ecole polytechnique de Louvain

Degree label

Master [120] : ingénieur civil en chimie et science des matériaux, à finalité spécialisée

Abstract

Fight climate change, primarily caused by the rampant growth of anthropogenic carbon dioxide (CO2) emissions, is a global priority today. A transdisciplinary analysis based on expert interviews has shed light on the challenges of reducing greenhouse gas (GHG) emissions by 2050 and defined the role of CO2 capture technologies, particularly direct air capture (DAC). Experts have emphasized the need to enhance energy efficiency while developing CO2 capture technologies that have proven effective in reducing CO2 emissions. DAC, an emerging technology, offers installation flexibility and requires less land compared to other technologies. However, it faces significant energy and financial challenges. This thesis focuses on cryogenic DAC, a lesser-known method compared to absorption and adsorption, with limited current applications. The study aims to understand the environmental impacts of "Cryo-DAC" a technology under development at Nagoya University in Japan, through a life cycle assessment (LCA). Cryo-DAC involves DAC of CO2 using a hybrid absorption-cryogenic system that uses CO2 desublimation with the cold energy supplied by liquefied natural gas (LNG). Cryo-DAC generates less CO2 than it captures. Furthermore, considering the uncertainties of the reference case and the lack of information regarding Cryo-DAC, scenario and sensitivity analyses were conducted to draw various conclusions. LNG as a cooling power source appears to be effective. Using alternative energy sources such as electricity to provide this cold energy would lead to an increase in equivalent CO2 emissions of nearly 48% under an idealized scenario assuming a coefficient of performance (COP) related to the cooling system of 1 and an 82% increase when considering the COP. The blower used to circulate the CO2-containing airflow within the Cryo-DAC system accounts for the majority of environmental impacts due to the carbon intensity of the electricity mix used.