An engineering model for coal devolatilization

Technical Report · Wed Nov 01 04:00:00 EST 1989

DOI:https://doi.org/10.2172/5339184· OSTI ID:5339184

Lau, Chun Wei; Niksa, S.

There are three distinct modeling projects in this program: (1) an expedient reaction model for coal devolatilization for large scale combustor simulators; (2) a theoretical framework to explain the behavior of different coal types; and (3) an analysis of the chemistry, heat and mass transport in the vicinity of individual coal particles, to begin to describe the initial stages of the combustion of entrained coal particles. The engineering model was developed before this program began, and has now been validated against several wire-grid studies of HVA bituminous coals. The transport analysis of devolatilizing and oxidizing coal particles, a two-component devolatilization model which resolves tar and noncondensibles was supplemented with a single heterogeneous combustion reaction at the particle surface. A transport analysis of the initial stages of pulverized coal combustion is formulated in terms of primary devolatilization, convective heat and mass transport, and heterogeneous oxidation at the particle surface. No homogeneous chemistry is included. Consequently this study aims to clarify the impact of the outward flux of volatiles on the heterogeneous ignition of individual coal particles. Primary devolatilization is represented by FLASHTWO, a recent model which predicts the yields and evolution rates of tar and a single noncondensible gaseous product, as well as the molecular weight distribution of tar. The transport analysis also includes oxygen and inert gas. Oxidation at the particle surface is described with a single nth-order global reaction, and the exotherm for CO production. 12 refs., 12 figs., 2 tabs.

• Research Organization: Stanford Univ., CA (USA). High Temperature Gasdynamics Lab.
• Sponsoring Organization: DOE/FE
• DOE Contract Number: FG22-88PC88900
• OSTI ID: 5339184
• Report Number(s): DOE/PC/88900-6; ON: DE90004140
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
014000* -- Coal
Lignite
& Peat-- Combustion
CARBONACEOUS MATERIALS
COAL
COMBUSTION PRODUCTS
COMBUSTORS
DEVOLATILIZATION
DOCUMENT TYPES
ENERGY SOURCES
FOSSIL FUELS
FUELS
IGNITION
MATERIALS
MATHEMATICAL MODELS
ORGANIC COMPOUNDS
OTHER ORGANIC COMPOUNDS
PROGRESS REPORT
TAR