Biomass is well known as a renewable and sustainable source of energy. However, open burning of biomass for energy generation causes the release of greenhouse gases and particulate matter. Hence, this study presents a self-sustainable pyrolysis system to produce biochar with lower energy and less environmental pollution.

The work reported in this paper explores the possibility of using self-generated pyrolysis volatiles as burning fuel to produce biochar using pyrolysis. The concept of this pyrolysis system is different from those of existing pyrolysis methods that adopt an electrical furnace and a microwave heating as the heating source. The findings from this study can provide valuable information to reduce the consumption of external heat supply, hence improving the overall economic feasibility of pyrolysis.

What is more interesting is that the pyrolysis process has enlarged the porosity on the resulting biochar. The longitudinal pores show sizes ranging from micro to macropores. Equally important, they also reported that the biochar has high carbon content of more than 80.0 weight percent and low amount of oxygen of less than 7.0 weight percent. The formation of macropores and the higher carbon content of biochar indicate its potential to be further upgraded into activated carbon with more applications.

According to their study, self-sustainable pyrolysis achieved a maximum temperature of 570 degrees Celsius to produce biochar with high fixed carbon and a higher heating value of 56.5 weight percent and 27.2 Mega-Joule per kg, respectively. The resulting biochar also demonstrated a high porosity of 202.2 square meters per g with great potential to be further activated into a high-grade adsorbent. They also suggested that the rate of production of self-sustainable pyrolysis could be scaled up by enlarging the metal reactor or converting it into continuous production to harvest biochar and bio-oil simultaneously. The biochar produced could be used as solid fuels or adsorbent for environmental remediation.