1 AIT Asian Institute of Technology

A study on the combustion of low grade fuels

AuthorRanu Pentananunt
Call NumberAIT Thesis no. ET-89-15
Subject(s)Combustion

NoteA thesis submitted in partial fulfillment of the requirement for the degree of Master of Science
PublisherAsian Institute of Technology
AbstractModifications were made on the fluidized bed rice husk combustor for the combustion of small size (<3.35 mm) lignite. Charcoal was used as start-up fuel. The effect of feed rate and excess air level on combustible loss was determined. Experimental results show that the combustion efficiency was high (> 90 %) and there existed an optimum excess air level at which maximum efficiency was achieved. Testing of torrefied wood for various properties and characteristics was carried out and compared with those of wood and charcoal. The effect of torrefaction in upgrading wood to a higher grade fuel was discussed. The results show that, while having superior weight and energy yields, torrefied wood exhibits a general trend of being an intermediate fuel between wood and charcoal. Thermogravimetric analysis was used to study the pyrolysis and char combustion kinetics of wood, torrefied wood and charcoal. Kinetic parameters were determined using the simple first order integral method and the effect of heating rate discussed. Each fuel showed its own unique TG curve. For pyrolysis, heating rate showed little effect on the TG curve but significantly affected the rate of volatile evolution. Good agreement between model prediction and TG data was obtained with two stage kinetics. At high heating rate, char combustion was affected by mass transfer and the reaction became diffusion controlled.
Year1989
TypeThesis
SchoolSchool of Environment, Resources, and Development (SERD)
DepartmentDepartment of Energy and Climate Change (Former title: Department of Energy, Environment, and Climate Change (DEECC))
Academic Program/FoSEnergy Technology (ET)
Chairperson(s)Bhattacharya, Sribas C.;
Examination Committee(s)Mora, Jean-Claude;Prida Wibulswas
Scholarship Donor(s)Government of Australia;
DegreeThesis (M.Sc.) - Asian Institute of Technology, 1989


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