Studies and modeling of atmospheric fluidized-bed combustion of coal
Thesis/Dissertation
·
OSTI ID:5784772
The three objectives of this study were to characterize the fluidization dynamics and heat transfer of beds composed of large non-uniform particles, to develop a comprehensive fluidized bed coal combustion model, and to verify the mathematical model using results from a fluidized bed combustion pilot plant. Experiments were carried out to characterize combustor type bed solids in terms of fluidization quality, minimum fluidization velocity, bed expansion, heat transfer to immersed tubes, and mixing patterns. Dimensionless parameter analysis was used to develop correlations for these phenomena. It was found that the behavior of combustor type bed solids (large particles with a wide size distribution) differs significantly from the behavior of the small uniform solids normally used to study fluidization. Two types of coal (Minto and Devco) were tested in a fluidized bed with the addition of limestone (Havelock) for sulfur capture. Typical operating conditions were: temperature 800-950/sup 0/C, fluidizing velocity 1.6-2.9 m/s, Ca/S molar ratio 1.4-4.5, and fines recycle ratio 0-1. Carbon utilization efficiencies of 88-98% were obtained, along with 50-100% sulfur capture. A mechanistic model was developed, taking into account the various processes occurring in fluidized bed combustion including: coal combustion (devolatilization, fragmentation, attrition and char combustion), elutriation, sulfur capture, nitrogen oxide reduction, interphase transfer, and homogeneous gas phase reactions. The model parameters were estimated using data from pilot plant experiments. The model accurately predicts observed trends, and model predictions show good agreement with experimental data.
- Research Organization:
- Queen's Univ., Kingston, Ontario (Canada)
- OSTI ID:
- 5784772
- Country of Publication:
- United States
- Language:
- English
Similar Records
Evaluation of attrition rate constants of char burning in fluidized beds by means of laboratory-scale combustors
Simulation of fluidized bed coal combustors. Final report
Some aspects of fluidized bed coal combustion and their effect on FBC modeling
Journal Article
·
Thu May 01 00:00:00 EDT 1986
· A.I.Ch.E. J.; (United States)
·
OSTI ID:5490113
Simulation of fluidized bed coal combustors. Final report
Technical Report
·
Wed Jan 31 23:00:00 EST 1979
·
OSTI ID:5668533
Some aspects of fluidized bed coal combustion and their effect on FBC modeling
Thesis/Dissertation
·
Thu Dec 31 23:00:00 EST 1981
·
OSTI ID:6037446