Solvothermal Carbonization of Wood Chips via the Dechlorination of PVC in Glycerol

We report the first investigation of biochar production via the solvothermal carbonization of wood chips and poly(vinyl chloride) (PVC) in glycerol. In this process, the dechlorination efficiency of PVC was significantly promoted by the reaction with wood chips or glycerol. When wood chips, PVC and glycerol with a weight ratio of 1 : 1 : 1.5 were heated at 200–260°C in an autoclave, solid products that contained a liquid remained at a temperature below 220°C. When the temperature was increased to 240°C, the liquid product disappeared, and resinified biochar was obtained. Accordingly, the process can be simplified without the need for separation after the carbonization. The biochar yield was 17.3% at 220°C and increased rapidly to 53.6% at 240°C. Similarly, the dechlorination rate was 30% at 220°C and increased to 80% at 240°C. This is attributed to the progress of the epoxy reaction, which was accompanied by dechlorination, in the temperature range of 220–240°C.