Hot Air Oven Drying of Maize Husks Biomass: Effects of Bed Depth and Temperature on Drying Kinetics, Moisture Diffusivity and Energy Requirement
Authors: Agbede OO, Ayanniyi KJ, Osuolale FN, Oke EO, Agarry SE, Ogunleye OO, Babatunde KA
The efficient conversion of maize husks biomass to bioenergy by pyrolysis, gasification and combustion requires the removal of moisture by drying. Hence, the hot air oven drying characteristics of maize husks was investigated. Beds (5 – 20 mm) of pulverized maize husks were dried at 80 – 120 oC in a laboratory hot air oven, to determine the effects of bed depth and temperature on the drying kinetics, effective moisture diffusivity and energy required for drying. Twelve thin layer drying models were fitted to the drying data. The drying rate of maize husks increased with increasing temperature and decreasing bed depth. The drying of maize husks took place entirely in the falling rate period. The effective moisture diffusivity increased from 8.03 x 10-9 to 2.83 x 10-8 m2 s-1 as bed depth increased from 5 to 20 mm, and from 1.11 x 10-8 to 2.10 x 10-8 m2 s-1 as the temperature increased from 80 to 120 oC, with an activation energy for drying of 18.6 kJ/mol. The specific energies required for drying the 5 - 20 mm husks beds at 80 - 120 oC were 17.43 – 34.95 kWh kg-1. The Weibull model best described the drying of pulverized maize husks.
Affiliations: Department of Chemical Engineering, Ladoke Akintola University of Technology, PMB 4000, Ogbomoso, Nigeria
Keywords: Maize Husks Biomass, Bioenergy, Hot Air Oven Drying, Effective Moisture Diffusivity, Thin Layer Model
Published date: 2019/12/30