Catalytic thermal activation of HTL-derived biochar to produce high surface area porous carbon

Author: Khang Huynh, Department of Chemical and Biological Engineering

Mentor: Dr. Rajesh Shende, Department of Chemical and Biological Engineering

Mentor: Dr. Vinod Amar, Department of Chemical and Biological Engineering

High surface area porous carbon is utilized for several applications such as water-purification, catalyst support, carbothermal reduction of oxides to nitrides, as electrodes in supercapacitors/asymmetric supercapacitors, batteries etc. Historically, the porous carbon or activated carbon is produced industrially from a variety of feedstocks using pyrolysis followed by chemical activation. A low-grade carbon obtained from the biomass after pyrolysis is also used for soil-amendment application. In this study, hydrothermal liquefaction of corn stover/biochemically derived unhydrolyzed solid (UHS) was performed at the temperatures and pressures of 250-300^oC and 800-1600 psi, respectively, and char was recovered along with the other products/co-products. The char was initially washed with water and dried at 105^oC, and thermally annealed at higher temperatures under inert atmosphere in the presence and absence of a catalyst. Char obtained before and after catalytic thermal annealing was characterized by the BET analyzer to determine specific surface area, pore volume, pore size and pore size distribution whereas its morphology was studied using scanning electron microscopy (SEM). Catalytic thermal annealing resulted in a very high specific surface area of 1300 m2/g with significant pore volume. Currently this char material is being investigated for the asymmetric supercapacitor with (Mn,Ti)-oxide opposite electrode. The specific capacitance of the catalytic thermally activated HTL-derived char will be compared with the graphene nanoplatelets.