Pyrolysis of blend biomass using TG MS

Pyrolysis of blend biomass has seldom been studied. Usually, TG-MS analysis are focused on biomasses blend with either coal, sewage sludge, plastic or coke to understand the changes in their thermal behaviour and kinetics. However, in large or commercial scale pyrolysis technologies, what would be the effect on the thermal and chemical characteristics of the product, if different types of biomasses are fed into the reactor is still unknown. In this study, the main aim was to pyrolyze different types of local individual biomass (rice husk, coconut shell, and sawdust) and their blend. The samples were subjected to TG-MS machine (TA instrument Discovery Q500 coupled with benchtop quadrupole mass spectrometer) from room temperature to about 800 °C with constant heating rate of 15 °C/min using pure nitrogen gas to study the thermal, kinetic and chemical behaviour during the pyrolysis process. The thermal behaviour of the biomass was divided into four main region; drying (< 150 °C), low volatile (150 °C – 240 °C), pyrolysis (260 °C – 400 °C), and char (> 400 °C). There was slight change in the thermal behaviour of blend biomass as compared to their individual biomass. In general, the activation energy decreased during main pyrolysis reaction when biomasses were blended. For instance, the activation energy of blend biomass CS50-RH50 (50-50 wt.%) was 96.84 kJ/mol as compared to their individual biomass CS (116.19 kJ/mol) and RH (114.40 kJ/mol). Similarly, some alternation in the chemicals and gas (CH4, C2H4, CHO, CO, C2H6, O2 and CO2) was observed in the blend biomass as present in the paper. Overall, a strong synergetic effect was found during pyrolysis of blend biomass. Therefore, blending of different types of biomass can be helpful either to alter the kinetics or the chemical products during pyrolysis. Ultimately, it would be beneficial in terms of logistics and conversion to process blend biomass in one pyrolysis or thermal conversion technology without much effect on the thermal and chemical characteristics.