Using the G-H space to show heat and work efficiencies associated with nitrogen plasma gasification of wood

Abstract

Energy in the form of plasma was used to thermally decompose wood in the presence of O2. Heat required to sustain the gasification reactions was provided indirectly by: (i) the electricity fed to the nitrogen N2 plasma torch; (ii) the chemical potential of the oxygen fed to the reactor. Two sets of experiments were carried out at 700 °C and 900 °C in a plasma reactor to investigate syngas composition variation. The results show that increasing the O2 flow rate reduced the lost work potential caused by the plasma electrical energy being degraded to heat, but increased the lost work during the reaction, as well as across the process, thus increasing the irreversibility of the overall process. Furthermore, a plasma torch that requires cooling is not the best way to add high temperature heat in form of electricity to the gasifier, as this results in enormous heat and work loss.