Non-isothermal drying of bio-wastes: kinetic analysis and determination of effective moisture diffusivity

ANDRÉS REYES URRUTIA; GERMÁN MAZZA; YANINA BALDAN; MARÍA PAULA FABANI ; ANABEL FERNANDEZ BRIZUELA; ROSA ANA RODRÍGUEZ

JOURNAL OF ENVIRONMENTAL MANAGEMENT

ACADEMIC PRESS LTD-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2020 vol. 262 p. 1 - 7

0301-4797

A macro-thermogravimetric analysis (macro-TGA) wasapplied to analyse the non-isothermal drying of different bio-wastes (quincesolid waste, grape marc and pumpkin shell from different enterprises located inSan Juan Province, Argentina). The experimental data were obtained at three heating rates (5, 10 and 15 K/min)and two different initial moisture contents (30 and 50% w/w). These data were fittedusing the Coats-Redfern and Sharp methods. The D2 modelshowed the best fitting for all experiments when using the Coats-Redfernmethod. It is assumed that drying occurs on the solid boundary. Thepredicted Ea values ranged from 43.60 to 64.50 kJ/mol for the threebio-wastes under the different experimental conditions. The Ea value slightly increaseswith the increase in heating rate because the wastes require moreenergy to undergo drying. Deff increasesmoderately with temperature at the beginning of the dehydration process; then, this increasing behaviour is significant due to the loss of continuousmoisture channels. Otherwise,Deff increaseswith the initial moisture content, showing that the humidity of the samples didnot reach the saturationcontent.