Thermal and catalytic pyrolysis of pine sawdust (Pinus ponderosa) and Gulmohar seed (Delonix regia) towards production of fuel and chemicals

Abstract

In this work, two waste biomass (pine sawdust, PW and gulmohar seeds, SG) were thermochemically converted with and without catalysts to find out their potential towards producing fuels and chemicals. Physicochemical characterization of these biomass confirmed their bioenergy potential for producing renewable fuel. Thermal pyrolysis of the biomass was performed at 500 °C temperature, 0.5 mm particle size, 80 °C min−1 heating rate, and 100 mL min−1 nitrogen flow rate, whereas catalytic pyrolysis was performed with CaO, CuO, and Al2O3 at different catalyst loading of 10 wt%, 20 wt%, 30 wt%, and 40 wt% respectively. The total pyrolytic liquid yield by thermal pyrolysis was found to be 39.39% for PW and 36.68% for SG, whereas catalytic pyrolysis at 20 wt% loading increased the liquid yield by 2.34–4.79 wt% for both the biomass. Thermal pyrolytic oil demonstrated increase in viscosity, density and decrease in acidity and heating value, whereas catalytic pyrolytic oil resulted in increased heating value, acidity, moisture, and decreased viscosity and density. FTIR analysis demonstrated the presence of aromatic compounds, phenols, alkanes, alcohols, acids, and aldehydes. GC-MS analysis confirmed that use of catalysts reduced the content of oxygenated and acidic compounds and increased that the amounts of alcohols and aldehydes in catalytic pyrolytic oil.