Production and characterization of sawdust-derived biocarbon monolith

Renewable energies have usually the problem that their supply is intermittent. They need energy storage systems (ESSs), that can capture energy at any time, store it and release it when it is necessary. Supercapacitors could be a good solution because of their long cycle-life, fast charging and discharging time and satisfactory values of energy and power densities. This thesis is focused on the study of a new, eco-friendly and cheap material for supercapacitor applications: biochar. It is a carbon-rich porous material obtained from pyrolysis of lignocellulosic biomass, in this case sugar maple wood. Biochar has always been used in agricultural systems to improve soil fertility. In the last decades interest in biochar has grown a lot thanks to its ability to face some important problems such as the climate change and water pollution and to be used as sustainable material in energy applications. This work is a first step of a new project focused on the production of electrodes for supercapacitors from delignified and compressed sawdust. It was conducted in the Green Technology Lab of the Department of Chemical Engineering of the University of Toronto. This thesis is focused on the production and characterization of sawdust-derived biocarbon monolith. A preliminary investigation of electrical conductivity of this biocarbon was conducted. The sawdust has undergone a pre-treatment process, has been compressed to produce pellets and has undergone a pyrolysis process. The main goal has been to understand how the change in pressure applied during the compression and the pyrolysis conditions can affect the physical and electrical properties of the final biocarbon structure. The idea of using compressed sawdust instead of monolith pieces of wood could have some advantages such as valorising a waste of the wood industry, producing a homogeneous and more uniform material, with the possibility to make the material repeatable, without depending on the original tree structure and producing a dense material, denser than the original wood.