A study on biochar for bioenergy and composite applications

This research focus on the production and characterization of the pyrolytic products (biochar, biooil and syngas) for potential bioenergy application, the application of biochar for treating wastewater and application of biochar in glassfibre reinforced polymer (GFRP) composites. The pyrolysis of crambe and meadowfoam oilcakes feedstocks was performed at 450 °C and 550 °C, at a heating rate of 10 °C/min with residence time of 30 mins. About 30-40 percent biochar, 40-50 percent biooil and remaining syngas were obtained. Lower biochar and higher biooil yields were seen when the pyrolysis temperature was increased. The energy value of biochar was in the range of 22-24 MJ/kg, that of biooil was above 35 MJ/kg. Carbon dioxide, Carbon monoxide, alkanes and alkenes were detected in syngas. The turbidity of the biochar treated wastewater was 50 NTU compared to its 1798 NTU initial measurement, and the foul smell was absent. Biochar from pyrolysis of spruce pellets in a two-stage rotating drum pyrolyzer at 450 °C, 10 °C/min heating rate and 30 mins residence time was crushed to size below 53 μm. Glassfibre reinforced Polymer composites were prepared w/o biochar at 5 percent and 10 percent by weight of the resin. Samples were vacuum infused for curing. The flame test suggested that higher biochar concentration in the composites retarded the flame better. DMA tests showed increased in storage moduli thus stiffness of composites with higher biochar. Reduced loss factor i.e. lower damping was experienced in the same composites. This signifies the importance of biochar in coal replacement, in wastewater treatment and in diversifying mechanical properties with better flame-retardant quality in composites. More importantly, it is bio-sourced and environmentally friendly.