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Department of Physics and Astronomy
University of Mississippi

Events

Event Information:

  • Tue
    23
    Oct
    2018

    Colloquium: Efficient Carbon Modification for Sustainable Food/Energy/Water Nexus

    4:00 pmLewis Hall 101

    Baharak Sajjadi
    Department of Chemical Engineering
    University of Mississippi

    Efficient Carbon Modification for Sustainable Food/Energy/Water Nexus

    Climate change mitigation is arguably the leading grand challenge facing mankind. Our critical reviews of physical modifications (Reviews in Chemical Engineering, 2018. in press, doi.org/10.1515/revce-2017-0113) and chemical modifications (Reviews in Chemical
    Engineering
    , 2018. in press, doi.org/10.1515/revce-2018-0003) of biochar in addition to our experimental results suggest that acoustic, photochemical and plasma treatments, in selected reaction environments and conditions; are capable of inducing either structural or functional group changes on carbonaceous materials. These tunable, low energy treatments have potential to mitigate climate change through a number of transformative tracks.

    The pioneering work of our transdisciplinary team revealed that single-staged ultrasound and photochemical treatments of
    biochar in H2O with dissolved CO2 results in fixation of C from CO2 on biochar, fixation of H from water on biochar, mineral leaching by water including minerals detrimental to gasification, increase in biochar's heating value (due to the 3 processes stated above), and increase in biochar's internal surface area (AIChE Journal, 2014. 60 (3):1054-1065). These synergisms seem to be tunable by feedstock, reactants stoichiometry and reaction conditions in pyrolysis, and treatments (Fuel, 2019. 235:1131-1145). Carbon and hydrogen fixations seem to be connected to the formation of H2, CO, formic acid, formaldehyde, and associated radicals during sonolysis of aqueous CO2. Similar to ultrasound waves, non-thermal plasma  can split water vapor and CO2 to excited chemicals and fuels including methanol, H2 and CO (Current Opinion in Green & Sustainable Chemistry, 2017. 3:45-49). The presence of carbon in the plasma system has not been explored. However, treatment of biochar in non-thermal chlorine plasma yields a high adsorption capacity of elemental mercury in flue gas due to the creation of Cl-active sites (Chemical Engineering Journal, 2018. 331C:536-544).

    In this seminar, we will discuss the potential routes of the observed synergisms in mitigation of climate change through CO2
    capture/recycle, energy production through advanced gasification, Remediation of global carbon cycle
    (Fuel, 2018. 225
    :287-298) & water resource (Ultrasonics Sonochemistry, 2018, in press). These treatments can also open new routes for tackling challenges such as water desalination through functionalized defected graphene membrane.