title: A Life Cycle Assessment Case Study of Coal-Fired Electricity Generation with Humidity Swing Direct Air Capture of CO2versus MEA-Based Postcombustion Capture.
abstract: Most carbon capture and storage (CCS) envisions capturing CO2from flue gas. Direct air capture (DAC) of CO2has hitherto been deemed unviable because of the higher energy associated with capture at low atmospheric concentrations. We present a Life Cycle Assessment of coal-fired electricity generation that compares monoethanolamine (MEA)-based postcombustion capture (PCC) of CO2with distributed, humidity-swing-based direct air capture (HS-DAC). Given suitable temperature, humidity, wind, and water availability, HS-DAC can be largely passive. Comparing energy requirements of HS-DAC and MEA-PCC, we find that the parasitic load of HS-DAC is less than twice that of MEA-PCC (60-72 kJ/mol versus 33-46 kJ/mol, respectively). We also compare other environmental impacts as a function of net greenhouse gas (GHG) mitigation: To achieve the same 73% mitigation as MEA-PCC, HS-DAC would increase nine other environmental impacts by on average 38%, whereas MEA-PCC would increase them by 31%. Powering distributed HS-DAC with photovoltaics (instead of coal) while including recapture of all background GHG, reduces this increase to 18%, hypothetically enabling coal-based electricity with net-zero life-cycle GHG. We conclude that, in suitable geographies, HS-DAC can complement MEA-PCC to enable CO2capture independent of time and location of emissions and recapture background GHG from fossil-based electricity beyond flue stack emissions.
authors.affiliation: Institute of Environmental Science, Leiden University , P.O. Box 9518, 2300 RA Leiden, The Netherlands.
authors.forename: Coen
authors.identifier: 0000-0001-8782-8860
authors.initials: C
authors.lastname: van der Giesen
authors.affiliation: Earth Institute, Columbia University , 500 W. 120th Street, 918 Mudd, New York, New York 10027, United States.|American Academy in Rome , Via Angelo Masina 5, 00153 Rome, Italy.
authors.forename: Christoph J
authors.initials: CJ
authors.lastname: Meinrenken
authors.affiliation: Institute of Environmental Science, Leiden University , P.O. Box 9518, 2300 RA Leiden, The Netherlands.
authors.forename: René
authors.initials: R
authors.lastname: Kleijn
authors.affiliation: Institute of Environmental Science, Leiden University , P.O. Box 9518, 2300 RA Leiden, The Netherlands.
authors.forename: Benjamin
authors.identifier: 0000-0002-0136-5656
authors.initials: B
authors.lastname: Sprecher
authors.affiliation: Center for Negative Carbon Emissions, Arizona State University , PO Box 873005, Tempe, Arizona 85287, United States.
authors.forename: Klaus S
authors.initials: KS
authors.lastname: Lackner
authors.affiliation: Institute of Environmental Science, Leiden University , P.O. Box 9518, 2300 RA Leiden, The Netherlands.|Copernicus Institute of Sustainable Development, Utrecht University , Heidelberglaan 2, 3584 CS Utrecht, The Netherlands.
authors.forename: Gert Jan
authors.initials: GJ
authors.lastname: Kramer
mesh_terms: D003031:Coal; D004560:Electricity; D019856:Ethanolamine; D006813:Humidity; D011210:Power Plants
chemical_list: D003031:Coal; D019856:Ethanolamine