Title
Solid biofuel from glycerol and agricultural waste as a source of energy
Authors
SUSANA CLAUDETE COSTA RICARDO LUIS BARCELOS and RACHEL FAVERZANI MAGNAGO

Received February 26, 2016
Published Volume 51 Issue 7-8 July-August
Keywords biofuel, cornstarch, solid fuel, rice husk, glycerol

Abstract
Rice husk is among the most abundant, low-cost renewable sources available for conversion into value-added products. The objective of this study was to evaluate the properties of specimens made from rice husk, cornstarch, glycerol, and acetic acid. For the preparation of the specimens, cornstarch was manually mixed in distilled water and heated up. Then, rice hulls (2 mm) were added to the main mixture. Specimen composites containing glycerol and acetic acid were mixed with cornstarch gel, homogenized, and then incorporated into rice husk. Four different composites were prepared, molded into cylinders and taken to the oven for drying. Overall moisture content, ash content, and upper and lower heating values were determined for all the specimens. The composites were characterized by Fourier transform infrared spectroscopy (FTIR), mechanical resistance to compressive strength, and smoke monitoring. Rice husk and cornstarch composites had the lowest overall moisture content (15.62%), whereas rice husk, cornstarch, and glycerol composites showed the lowest ash content (11.71%). The prepared solid fuel that reached the highest heating value was the one containing rice husk, cornstarch and glycerol, reaching an upper heating value of 13.47 MJ/kg and a lower heating value of 12.07 MJ/kg. The most resistant specimens (1.23 MPa) were those composed of rice husk, cornstarch, glycerol, and acetic acid. The developed solid fuels could replace satisfactorily traditional calorific sources, and were similar or better than conventional firewood and charcoal briquettes.