Premium
The ignition temperature of lignite char in a fluidized bed combustor
Author(s) -
Van Puyvelde Dennis,
Stubington John
Publication year - 1999
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.5450770114
Subject(s) - char , combustor , ignition system , fluidized bed , combustion , autoignition temperature , fluidized bed combustion , minimum ignition energy , particle (ecology) , waste management , materials science , chemistry , thermodynamics , engineering , geology , physics , oceanography , organic chemistry
This paper summarises the experimental and modelling work carried out for the variation of bed ignition temperature of a fluidized bed combustor with the char particle diameter and the fluidizing velocity. A lignite char was used and its reactivity was represented using data from Field (1967) and Turnbull and Davidson (1984). The modelling involved solving the steady state heat balance around the fluidized bed combustor at the ignition temperature. A correlation of the total area of char ignited per unit bed mass was determined as a function of the char particle diameter and the fluidizing velocity. This correlation was used to determine the ignition temperature of the fluidized bed combustor operating at different conditions. The fluidized bed combustor heat balance was then solved for the bed ignition temperature which was influenced by both the rate of heat loss from the bed and the reactivity of the char. A sensitivity analysis suggests that the chemical rate reaction coefficient is the most prominent variable when determining the ignition temperature of a fluidized bed combustor.