The Canadian Society for Bioengineering

The Canadian society for engineering in agricultural, food, environmental, and biological systems. / / La Société Canadienne de Génie Agroalimentaire et de Bioingénierie
La société canadienne de génie agroalimentaire, de la bioingénierie et de l’environnement

CSBE09403

TORREFACTION PROCESS FOR AGRICULTURE AND FOREST RESIDUES

Animesh Dutta

Engineering Department, Nova Scotia Agricultural College, P.O. 550, Truro, NS, Canada, B2N 5E3.

Anuphon Pimchuai

Mechanical Engineering Department, Burapha University, Muang, Chonburi 20131, Thailand.

ABSTRACT

The overall objective of this research is to investigate the torrefaction process in order to remove some disadvantages of agriculture residues as a fuel; more importantly to enhance their solid fuel qualities. Five agriculture residues (rice husk, sawdust, peanut husk, bagasse and water hyacinth) are studied. The two main operating parameters, temperature and residence time for the process were varied at 250, 270, 300 oC and 1, 1.5, 2 hours, respectively. Subsequently, the torrefied product was characterized by evaluating its yields, proximate analysis, heating value and as well as the hydrophobic properties using a wide range of laboratory scale methods. The optimum condition based on mass and energy balance for the torrefaction process was carefully observed. The torrefied products have more brown color, reduced the moisture content and volatile matter while the ash, fixed carbon content and energy density increased. Over the raw materials studied, the torrefied bagasse at 300 oC and 1.5 hours had resulted in highest HHV content which was 25.68 MJ/kg-product comparable to the HHV of lignite. Depending on the severity of the torrefaction conditions, the torrefied fuel can contain up to 98% of the original energy content on a mass basis. The study also concluded that operating temperature is the single most significant parameter that has more effect on producing better torrefied product than that of the residence time.

Keywords: Biomass; Torrefaction; Agriculture Residue; Pyrolysis; Pre-treatment