相关论文

Kinetics of combustion of a pulverized brown coal char between 630 and 2200°K

Abstract:Measurements have been made of the combustion kinetics of size-graded fractions (89, 49, and 22 μm) of a char prepared from Yallourn brown coal. Reactions were carried out in an entrainment reactor (between 900 and 2200°K) at oxygen partial pressures of about 0.2 and 0.1 atm, and in a fixed-bed reactor (between 630 and 760°K) at about 0.1 atm oxygen. Above 900°K, the 89 and 49 μm fractions were subject to rate control by the coupled processes of pore diffusion and chemical reaction on the pore walls; the rate coefficient, Ra,c (the rate of carbon combustion per unit external area of the particle per (atmosphere of oxygen)0.5), being given by R a , c = 9.3 exp [ − 16 , 200 / ( ℝ T p ) ] , g / [ cm 2 sec ( atm ) 0.5 ] , where Tp is the temperature of the particle in °K and R is in cal/(mol °K). Below 760°K, the 89 and 49 μm fractions were found to react with rate control by chemical reaction alone. Above 900°K rate control for the 22 μm fraction lay intermediate between these two limits. At 1800°K the reactivity of the brown coal char is a factor of 4 higher than that of anthracite, and is 50% higher than that of a char from a low-rank bituminous coal; however, at 770°K the reactivity of the char is one to six orders of magnitude higher than the reactivities of other carbons.

引用
A Note on Fractional Sumudu Transform
J. Appl. Math.
2010
Rotary Cement Kiln Simulator (RoCKS): Integrated modeling of pre-heater, calciner, kiln and clinker cooler
2007
Explosibility of Victorian brown coal dust
1987
Combustion of wood charcoal
1977
Flash pyrolysis of coals. 1. Devolatilization of a Victorian brown coal in a small fluidized-bed reactor
1979
Heterogeneous Reactions of Char and Carbon
1979
Analysis of Char Combustion Including the Effect of Pore Enlargement
1980
Extinguishment of burning wood charcoal surfaces
1980
The order, Arrhenius parameters, and mechanism of the reaction between gaseous oxygen and solid carbon
2001
Kinetic parameters of the intrinsic reactivity of woody biomass and coal chars via thermogravimetric analysis
2017
Wood charcoal combustion and the effects of water application
1980
Modeling of coal-combustion processes
1984
The Reactivity of a Porous Brown Coal Char to Oxygen between 630 and 1812° K
1974
Numerical flow simulation of dust deflagrations
1992
The combustion of Loy Yang brown coal char
1989
Advanced modeling approaches for CFD simulations of coal combustion and gasification
2021
A new char combustion kinetic model – Part 2: Empirical validation
2012
On-line modeling of NOx formation in a coal boiler
2013
Pulverized coal char combustion: the effect of particle size on burner performance
1998
Chemical Looping with Copper Oxide as Carrier and Coal as Fuel
2011