LAUSR

Abstract The physio-chemical properties of biochar from nitrogen plasma reactor were investigated. The amount of biochar and its sieve particle size distribution decreased with increase in oxygen feed for gasification and increase in temperature for both biomass conversion processes. For gasification, the pore volume increased from 0.001 m3/g (raw) to 0.144 m3/g (biochar) at 700 °C and to 0.188 m3/g at 900 °C. The pore size of biochar (pyrolysis) increased from 21.948 A at 400 °C to 34.626 A at 1000 °C. For both processes, the biochar exhibited a more broken and non-parallel structure compared to that of the feed wood pellets. During plasma gasification, all the particles of size x x  > 2 mm remained in the reactor chamber. The solid carbon element content in the biochar increased by 8% up to 93% when pyrolysis temperature was increased from 400 °C to 1000 °C. The carbon content decreased from 89% to 80% at 700 °C and from 93% to 86% at 900 °C when oxygen flowrate was increased from 0.15 kg/h to 0.6 kg/h. Agglomeration of elements K, Si, Mg, Al and Fe was observed as temperature increased for pyrolysis. The FTIR spectra revealed a new peak at 773 cm−1 attributed to C H bond related to olefin and aromatic structure in all biochar. These parameters are vital to understand practical process flow distributions and product separation mechanisms resulting from transportation of biochar within biomass systems to improve their design.