(6ek) Efficient Carbon Modification for Sustainable Food/Energy/Water Nexus

• Bioenergy and Biofuels (Biodiesel and Biochar)
• Activation of Carbonaceous Graphitic Structures
• Wastewater Treatment
• CO₂ Capture
• Sono-Physics (acoustic-based bio-processes)
• Computational Fluid Dynamic (CFD) simulation
• Techno Economic Analysis (TEA)

Teaching Interests: All Chemical Engineering Courses

Abstract

The sustainable food / energy / water (FEW) nexus is arguably the leading grand challenge facing mankind. Our critical reviews of physical modifications (Reviews in Chemical Engineering, 2019. in press, doi.org/10.1515/revce-2017-0113) and chemical modifications (Reviews in Chemical Engineering, 2019. 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 play a major role in FEW systems through a number of transformative tracks.

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 these plasma systems 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, 2019, 51, 20-30,). These treatments can also open new routes for tackling challenges such as water desalination of through functionalized defected graphene membrane. We are exploring the potential of employing these low-temperature biochar modification technologies on improving the soil productivity through water- and nutrient-holding capacity, and pH adjustment. Moreover, the presence of essential small molecules, such as H₂, CO, formaldehyde, etc., produced during the treatments are likely to have other applications in FEW nexus and climate change mitigation.