Dendrometric characterization of corn cane residues and drying models in natural conditions in Bolivar Province (Ecuador)

The use of biomass raw material from agricultural areas is a challenge for Ecuatorian government. However there is lack information about surveying systems and processing in its height and weather conditions. The objective of this work was to develop methods to quantify straw residues, easily applicable in corn areas of Guaranda (Ecuador), and model the drying process at different air conditions. Two dendrometric equations were obtained for predicting dry available biomass by stem and cultivated area respectively, from corn mean height and radius of the stem. High coefficients of determination were obtained (0.94 and 0.97 respectively). Straw chips with initial moisture content ranging from 70 to 80% with an average moisture content of 76.7% wet basis were dried until they reached constant moisture content. Traditional models used to describe the drying process of agricultural products were employed to fit the observed data of the drying process of straw corn chips. Among the tested models, the Midili, Page, and sigmoid model were those that best fit the observed data representing the drying process. The effective diffusion (Def) was determined by means of an analytical solution of Fick's second law. Effective moisture diffusivity values obtained at natural outdoor drying conditions were 2.443E-11 and 2.035E-10 m2/s, for the first and second falling periods, respectively.