UNI-CONTROL
COAL SUPPLY CHAIN MANAGEMENT.
Lignite Coal
Sub-Bituminous Coal
Peat Coal
Bituminous Coal
Anthracite
Coal and Coke Calculation Protocols
*** Net CV calculation - refer to ASTM D5865 / ISO 1928
*** Moisture conversion to different bases - refer to ASTM D3180 / ISO 1170
1. Bases Conversion Factors:
Ref: ASTM D3180 / ISO 1170 - Conversion to different moisture bases
a. Dry factor (converts AD to Dry)
(100-ADM)/100
(100-ADM)/100 Dry = AD / ((100-ADM)/100)
b. AR factor (converts Dry to AR (100-TM)/100
(100-TM)/100 AR = Dry x ((100-TM))/100)
c. DAF factor (converts Dry to DAF) (100-Dry Ash)/100
(100-Dry Ash)/100 DAF = Dry / ((100-Dry Ash)/100)
Where:
TM Total Moisture
Total MoistureADM Air Dried Moisture (Moisture in the Analysis Sample)
AR As Received Basis
AD As Determined (Air Dried) Basis
Dry Dry Basis
DAF Dry Ash Free Basis
2. Two Stage Total Moisture Formula (Refer to ASTM / ISO):
Two stage total moisture determination is used when the coal sample is too wet to divide or crush without the potential of loosing significate amounts of moisture.
TMar, % = [RMad, % x (100 - FMad, %) / 100] + FMad %
M = Total moisture; FM = Free Moisture; RM = Residual moisture
3. Calorific Value Conversion Factors:
MJ/kg = kcals/kg / 238.846
MJ/kg = Btu/lb / 429.923
kcal/kg = MJ/kg x 238.846
kcal/kg = Btu/lb / 1.8
Btu/lb = MJ/kg x 429.923
Btu/lb = kcals x 1.8
4. CO2 Emission Factor:
t/CO2/TJ = As Received Carbon x 3.667 x [10,000/NCV(p)] in kJ/kg= As Received Carbon x 3.667 x [2388.46/NCV(p)] in kcal/kg
5. Fuel Ratio:
Fuel Ratio = Fixed Carbon / Volatile Matter.
6. Hydrogen in Coal, Refer to ASTM 3180 / ISO 1170:
In-as-much as hydrogen values may be reported on the basis of containing or not containing the hydrogen in water (moisture) associated with the sample, alternative conversion procedures are defined below:
Use following conversions to report H, including or excluding H in moisture. Total Hydrogen as-determined (ad): includes H in the moisture analysis.
6.1 Hydrogen (excluding H in moisture):
H(dry base) = [Total Hydrogen(ad)-(AMx0.1119)] x (100/(100-AM))
6.2 Hydrogen (including H in moisture):
H(ar) = [Total Hydrogen(db) x ((100-TM)/100)]+(0.1119*TM)
6.3 ISO 1170 reports H as air-dried basis excluding H in the analysed moisture:
H(air-dried) = Total Hydrogen(as-determined) - (Analysis Moisture x 0.1119)
Hydrogen and Oxygen Factors based on the atomic weight of H20
Hydrogen = Moisture X 0.1119
Oxygen = Moisture X 0.8881
7. Net Calorific Value (NCV) Conversion Factors:
Ref: Net Calorific Value (ASTM D5865-03).
The heat produced by combustion of a substance at a constant pressure of 0.1 Mpa (1 Atm), with any water formed remaining as vapour.
ISO 1928-1995 at constant volume.
Qv, net,m,J/g =( Q gr,v,d - 206.0 [ wHd ] ) x (1-0.01xMT) - (23.05x MT)
Qv, net,m,kcal/kg = ( Q gr,v,d - 49.20 [ wHd ] ) x (1-0.01xMT) - (5.51x MT)
ISO 1928-1995 at constant pressure.
Qp, net,m,J/g =
{ Q gr,v,d - 212.2 [ wHd ] - 0.8 x [wOd + wNd] } x (1- 0.01MT) - 24.43 x MT
Qp, net,m,kcal/kg =
{ Q gr,v,d - 50.68 [ wHd ] - 0.191 x [wOd + wNd] } x (1- 0.01MT) - 5.84 x MT
[ wHd ] = H content of the sample less Hydrogen present in the moisture
w(H)d = w(H) x 100/100-MT
MT= Total Moisture
ASTM 5865/3180 at constant pressure
Qp(net)ar,J/g = Qvar(gross) - (215.5 x Har)
Qp(net)ar,Btu/lb = Qvar(gross) - (92.67 x Har)
Qp(net)ar,kcal/kg = Qvar(gross) - (51.47 x Har)
Har = total hydrogen where hydrogen includes hydrogen in Sample Moisture
Har = [(Had-0.1119xMad) x (100-Mar)/(100-Mad)] + 0.1119 x Mar
8. Seyler’s Formula:
Various parameters of Coal can be estimated from the Ultimate Analysis and Calorific Value determinations, using Seyler's formula, and other similar calculations (e.g. Dulong's formula).
Reference:
* COAL -Typology -Physics -Chemistry -Constitution
D.W. Van Krevelen (third edition 1993) Page 47
VMdaf = 10.61Hdaf - 1.24Cdaf + 84.15
Hdaf = 0.069 (Qdaf/100+VMdaf) - 2.86
Cdaf = [0.59 (Q,daf/100 - 0.367VMdaf) + 43.4]
** ISO 1928-1995 Part E.3.3
Estimate of the hydrogen content, calculated using Seyler's Formula
wH = 0.07 x w(V) + 0.000165 x qv,gr,m - 0.0285 x [ 100 - MT - w(A)
w(H) - is the H content of sample less H contained in moisture, as % mass
w(V) - is the VM content of sample with moisture content MT, as % mass
w(A) - is the ash content of sample with moisture content MT, as% mass
qv,gr,m - is the gross CV of sample with moisture content MT, in joules/g
Note.1** Only valid when the calculated Hdb is greater than 3%
Note.2* Only valid when the Odaf content is less than 15%
Note.3 Can give erroneous results if coal shipments are a blend of low and high rank coals
9. Dulong's Formula
GCV(db) = 333xC(db) + 1442(H(db) - O(db) / 8) + 93xS(db)
GCV is in (kJouls/kg dry basis). C, H, O, S as percent on a dry basis
