Recycling CO2from flue gas for CaCO3nanoparticles production as cement filler: A Life Cycle Assessment Articles uri icon

publication date

  • March 2021

start page

  • 101446

volume

  • 45

International Standard Serial Number (ISSN)

  • 2212-9820

Electronic International Standard Serial Number (EISSN)

  • 2212-9839

abstract

  • CaCO3 nanoparticles as filler have received considerable attention for the mechanical improvement that they
    provide to cements. However, their life-cycle impact on the environment remains almost unexplored, even if the
    cement industry is considered one of the largest CO2 emitters. In this perspective, this research work assessed a
    novel method for using CO2 from cement flue gases to produce nanoCaCO3 as cement filler within the cradle to
    cradle thinking. For this purpose, two routes of CO2 capture were assessed followed by the study of the synthesis
    of CaCO3 through a mineral carbonation. Three scenarios for the synthesis of CaCO3 nanoparticles were assessed
    targeting the use of waste or by-products as raw materials and recirculation of them to reduce any kind of
    emission. The three scenarios were evaluated by means of the Life Cycle Assessment methodology. Once the best
    considered route for nanoCaCO3 production was determined, this research work examined the environmental
    effect of including 2 wt% of CaCO3 nanoparticles into the cement. Closing the loop follows a circular economy
    approach since the CO2 is captured within the same cement factory. The results were compared with conventional
    Portland cement. Regarding nanoCaCO3 results, the scenario with simultaneous production of NH4Cl, and
    using as calcium source CaCl2 deriving from the soda ash Solvay process, proved to be the best option. Moreover,
    when cement was filled with 2 wt% of this nanoCaCO3, the benefit in terms of emission reductions in the Climate
    Change category was higher than 60 % compared to the conventional Portland cement.

keywords

  • life cycle assessment (lca); cradle to cradle; carbon capture and utilization (ccu); mineral carbonation; portland cement