Life Cycle Assessment of Direct Air Carbon Capture and Storage with Low-Carbon Energy Sources

Abstract

Prospective energy scenarios usually rely on Carbon Dioxide Removal (CDR) technologies to achieve the climate goals of the Paris Agreement. CDR technologies aim at removing CO2 from the atmosphere in a permanent way. However, the implementation of CDR technologies typically comes along with unintended environmental side-effects such as land transformation or water consumption. These need to be quantified before large-scale implementation of any CDR option by means of Life Cycle Assessment (LCA). Direct Air Carbon Capture and Storage (DACCS) is considered to be among the CDR technologies closest to large-scale implementation, since first pilot and demonstration units have been installed and interactions with the environment are less complex than for biomass related CDR options. However, only very few LCA studies - with limited scope - have been conducted so far to determine the overall life-cycle environmental performance of DACCS. We provide a comprehensive LCA of different low temperature DACCS configurations - pertaining to solid sorbent-based technology - including a global and prospective analysis.

Life cycle and techno‐economic assessments of direct air capture processes: An integrated review

“…Lower impacts than conventional diesel production and several biofuels are achieved, if and only if a low-carbon electricity source is used, as illustrated in Figure 9. Under the conditions detailed by Liu et al, 45 capturing ambient air CO 2 using a DAC technology and converting it to 43 Terlouw et al, 49 and Madhu et al, 47 synthetic fuel leads to carbon reduction if an electricity emissions factor lower than 0.37 kgCO 2 -eq per kWh is considered, compared with a case where CO 2 from a natural gas combined cycle power plant is captured and converted to synthetic fuel. Also, if the emissions intensity of the supply exceeds 0.14 kgCO 2 -eq per kWh, the climate change impacts of the DAC-based synthetic fuel will be worse than that of conventional diesel (see Figure 9).…”

“…Also, the economic costs and environmental impacts of DAC equipment, machinery, operations, and CO 2 disposal, including its use, should be assessed using a full cradle-to-grave approach, as stated by relevant literature. 49 These assessments should also include alternative evaluations of other pathways that achieve at least equivalent CO 2 reductions, such as BECCS and reforestation. There is a large dependency on the energy sources used for CO 2 capture.…”

“…Independent of the scenario, the investigated process effectively captures and stores CO 2 from the ambient air. The authors point out the large dependency on the energy sources used for the DAC system 49 . (9) Two scenarios were defined where the DAC system is powered by either coal‐fired power plants or a locally installed PV system.…”

“…LCA of DACCS system comprises the CO 2 storage stage, that is, the environmental impacts related to the infrastructure (eg, CO 2 compression stations and pipelines), the drilling of injection wells, and CO 2 leakage during the CO 2 transportation. Terlouw et al 49 proposed a comprehensive LCA of DACCS, based on Climeworks technology, including several processes needed for CO 2 storage and appropriate site location discussions. Deutz and Bardow 43 evaluate two commercial low‐temperature DACCS systems, operated by Climeworks, and the associated supply chains focusing mainly on the electricity demand for CO 2 injection.…”

“…Global warming potential of captured CO 2 from ambient air when including subsequent CO 2 storage, according to the carbon footprint of the electricity supply. Figure based on data from Deutz and Bardow, 43 Terlouw et al, 49 and Madhu et al, 47 using linear regression (see these references for more details related to the systems involved). BR, Brazil; CA, Canada; CH, Switzerland; CN, China; DE, Germany; ENTSO‐E, European energy mix; FR, France; Global, Global energy mix; IN, India; IS, Iceland; MX, Mexico; NG, natural gas; PL, Poland; PV, photovoltaics; UK, United Kingdom; USA, United States…”