Proximate analysis, calorific value and main chemical constituents of selected lignocellulosic biomass

Sustainable exploitation and use of lignocellulosic biomass as a renewable energy source is essential for replacing conventional fossil fuels. Many efforts are being focused on identifying suitable biomass species that can provide high energy outputs to produce biofuels. In this study, seven biomasses were studied from fast growth species for their usage as bioenergy feedstocks. Proximate analysis, specifically volatile matter (VM), fixed carbon (FC), ash (A) and moisture (M),  as well as lignin, holocellulose, cellulose, hemicellulose content and gross calorific value were measured in the stem wood of Ochroma pyramidale (Cav. ex Lam.) Urb., Ceiba pentandra (L.) Gaertn. and Hevea brasiliensis Muell. Arg. trees, and in the grass stalks of Cenchrus echinatus L., Panicum maximum Jacq., Pennisetum purpureum Schum. and Rottboellia cochinchinensis (Lour.) Clayton. Significant differences were found among the different biomasses for all the average measurements. Values ranged from 70.11 to 86.18% for VM, 13.3 to 18.0% for FC, 5.90 to 8.35% for M and 0.52 to 13.37% for ash. Grass biomass showed less VM, more FC and ash than the woody biomass. Values of chemical constituents were also variable with a range from 18.82 to 24.72% for lignin, 63.53 to 79.57% for holocellulose, 30.52 to 44.93% for cellulose and 30.45 to 38.00% for hemicellulose. Gross calorific value was between 17.33 and 19.27 MJ/kg. Woody biomass showed higher average values in chemical composition and gross calorific value than grass biomass. These results indicate that the studied biomasses have the potential for use as a bioenergy feedstock.