Page 107 - Biomass Gasification, Pyrolysis And Torrefaction Practical Design and Theory

Chapter | 3 Biomass Characteristics 85

G(x), F(x), H(x) functions of the cell structure and its dimensionless length of the bio-
mass in Eq. (3.10) ( )
HR heat of combustion or heat of reaction (kJ/mol)
HF heat of formation (kJ/mol)
H weight percentage of hydrogen (%)
HHV high heating value of fuel (kJ/kg)
latent heat of vaporization (kJ/kg)
h g
effective thermal conductivity of biomass (W/m K)
K eff
thermal conductivity of the solid in dry wood (W/m K)
K s
thermal conductivity of the moisture in dry wood (W/m K)
K w
thermal conductivity of the gas in dry wood (W/m K)
K g
radiative contribution to the conductivity of wood (W/m K)
K rad
LHV low heating value of fuel (kJ/kg)
biomass moisture expressed in wet basis ( )
M wet
biomass moisture expressed in dry basis ( )
M dry
moisture percentage (by weight, %)
m d
M weight percentage of moisture (%)
mass of surface moisture in biomass (kg)
M a
mass of inherent moisture in biomass (kg)
M i
M f mass of fuel (kg)
M w mass of moisture in the fuel (kg)
M ash mass of ash in the fuel (kg)
m i mass fraction of the ith gas ( )
MW molecular weight of gas mixture ( )
n number of moles ( )
n i mole fraction of the ith gas ( )
N weight percentage of nitrogen (%)
O weight percentage of oxygen (%)
P i partial pressure of the ith gas (Pa)
P total pressure of the gas (Pa)
Q heat content of fuel (kJ)
R universal gas constant (8.314 J/mol K)
sp.gr specific gravity ( )
S weight percentage of sulfur (%)
T temperature (K)
weight of wet biomass (kg)
W wet
weight of dry biomass (kg)
W dry
VM weight percentage of volatile matter (%)
3
V volume of gas (m )
volume fraction of the ith gas ( )
V i
heat of combustion or reaction, kJ/mol
ΔH comb
3
true density of biomass (kg/m )
ρ true
3
apparent density of biomass (kg/m )
ρ apparent
3
bulk density of biomass (kg/m )
ρ bulk
ε void fraction ( )