Aspen Physical Property System - Physical Property Models

m = Mineral-matter-free basis
General Coal Enthalpy Model
The general coal model for computing enthalpy in the Aspen Physical Property
System is HCOALGEN. This model includes a number of different correlations
for the following:
� Heat of combustion
� Heat of formation
� Heat capacity
You can select one of these correlations using an option code in the Properties
Advanced NC-Props form. (See the Aspen Plus User Guide, Chapter 6). Use
option codes to specify a calculation method for properties. Each element in
the option code vector is used in the calculation of a different property.
The table labeled HCOALGEN Option Codes (below) lists model option codes
for HCOALGEN. The table is followed by a detailed description of the
calculations used for each correlation.
The correlations are described in the following section. The component
attributes are defined in Aspen Plus User Guide, Chapter 6.
Heat of Combustion Correlations
The heat of combustion of coal in the HCOALGEN model is a gross calorific
value. It is expressed in Btu/lb of coal on a dry mineral-matter-free basis.
ASTM Standard D5865-07a defines standard conditions for measuring gross
calorific value. (Earlier ASTM Standard D-2015 used the same conditions.)
Initial oxygen pressure is 20 to 40 atmospheres. Products are in the form of
ash; liquid water; and gaseous CO2, SO2, and NO2.
You can calculate net calorific value from gross calorific value by making a
deduction for the latent heat of vaporization of water.
Heat of combustion values are converted back to a dry, mineral-mattercontaining
basis with a correction for the heat of combustion of pyrite. The
formula is:
The heat of combustion correlations were evaluated by the Institute of Gas
Technology (IGT). They used data for 121 samples of coal from the Penn
State Data Base (IGT, 1976) and 457 samples from a USGS report (Swanson,
et al., 1976). These samples included a wide range of United States coal
fields. The constant terms in the HCOALGEN correlations are bias corrections
obtained from the IGT study.
Boie Correlation:
Parameter Name/Element Symbol Default
BOIEC/1 a 1i 151.2
BOIEC/2 a 2i 499.77
300 4 Nonconventional Solid Property Models