Title: Effect of air flow rate and residence time on biodrying of cassava peel waste

Authors: Ranjit Sen; Ajit P. Annachhatre

Addresses: Environmental Engineering and Management Programme, School of Environment, Resources and Development, Asian Institute of Technology, Khlong Luang, Pathumthani 12120, Thailand ' Environmental Engineering and Management Programme, School of Environment, Resources and Development, Asian Institute of Technology, Khlong Luang, Pathumthani 12120, Thailand

Abstract: Effect of air flow rate and residence time on biodrying of cassava peel mixed with activated sludge waste was investigated at laboratory scale. Air flow rates of 0.01 to 0.04 m³kg⁻¹h⁻¹ and residence times of 12 to 20 days were maintained during biodrying process. Calorific value of cassava peel increased from its initial value of 4,660 kJ kg⁻¹ to a maximum value of 10,406 kJ kg⁻¹ (wet weight basis) when air flow rate of 0.03 m³kg⁻¹h⁻¹ and residence time of 16 days were maintained during biodrying. Under this operating condition, moisture content of cassava peel reduced from its initial value of 70.40% to a final value of 24.00%. Maximum feedstock temperature of 64.25°C at the top layer and 59.00°C at the bottom layer were recorded at this condition. Air flow rate of 0.03 m³kg⁻¹h⁻¹ with 16-day residence time was found optimum for biodrying of mixed materials yielding an increase of 123% in calorific value.

Keywords: agro-industrial waste; cassava peel; biodrying; residence time; air flow rate; biodrying index; calorific value; activated sludge; moisture content; feedstock temperature.

DOI: 10.1504/IJETM.2015.068414

International Journal of Environmental Technology and Management, 2015 Vol.18 No.1, pp.9 - 29

Received: 30 Oct 2013
Accepted: 14 Nov 2014
Published online: 06 May 2015 *

Full-text access for editors Full-text access for subscribers Purchase this article Comment on this article