sandlercubics 0.5.1

Cubic equations of state from Chemical, Biochemical, and Engineering Thermodynamics (5th edition) by Stan Sandler

Sandlercubics

Digitized cubic equations of state from Sandler's 5th ed.

Sandlercubics implements a python interface to the cubic equations of state found in Chemical, Biochemical, and Engineering Thermodynamics (5th edition) by Stan Sandler (Wiley, USA). It should be used for educational purposes only.

Currently only the generalized vdW and generalized Peng-Robison equations for pure substances are implemented.

Installation

sandlercubics is available via pip:

pip install sandlercubics

Usage

Command-line interface

A volumetric calculation example on methane using Peng-Robinson:

$ sandlercubics state -T 400 -P 0.5 -eos pr -n methane
EOS  = pr
T    = 400.00 K
P    = 0.50 MPa
Z    = 1.00
v    = 0.006628 m3/mol
Hdep = -54.75 J/mol
Sdep = -0.11 J/mol-K
Tc    = 190.40 K
Pc    = 4.60 MPa
omega = 0.011

State calculation example:

$ sandlercubics delta -T1 350 -P1 7.5 -T2 400 -P2 15.5 -n methane -eos pr --show-states
State 1:
EOS  = pr
T    = 350.00 K
P    = 7.50 MPa
Z    = 0.93
v    = 0.000359 m3/mol
Hdep = -989.93 J/mol
Sdep = -2.13 J/mol-K

State 2:
EOS  = pr
T    = 400.00 K
P    = 15.50 MPa
Z    = 0.95
v    = 0.000204 m3/mol
Hdep = -1412.32 J/mol
Sdep = -2.86 J/mol-K

Property differences:
Delta H = 2416.63 J/mol
Delta S = 0.02 J/mol-K
Delta U = 2883.75 J/mol

Constants used for calculations:
Tc    = 190.40 K
Pc    = 4.60 MPa
omega = 0.011
CpA   = 19.25 J/mol-K
CpB   = 5.213e-02 J/mol-K^2
CpC   = 1.197e-05 J/mol-K^3
CpD   = -1.132e-08 J/mol-K^4

API

Below we create a PengRobinsonEOS object to reproduce the first calculation:

>>> from sandlercubics.eos import PengRobsinsonEOS
>>> from sandlerprops.properties import PropertiesDatabase
>>> db = ProperitesDatabase()
>>> m = db.get_compound('methane')
>>> s1 = PengRobinsonEOS(Tc=m.Tc, Pc=m.Pc/10, omega=m.Omega)
>>> s1.T = 400
>>> s1.P = 0.5
>>> s1.v.item()  # it is a np float
0.0066279171348771915

Release History

• 0.5.0
  • Output of two-phase saturated states allowed
• 0.4.0
  • Heat and entropy of vaporization properties added
• 0.3.0
  • Soave-Redlich-Kwong equation implemented
• 0.2.1
  • redefined CubicEOS abstract class
• 0.2.0
  • uses StateReporter
  • delta subcommand implemented
• 0.1.1
  • fixed erroneous thank-you message
• 0.1.0
  • Initial version, implements vdw and PengRobinson

Meta

Cameron F. Abrams – [e-mail]

Distributed under the MIT license. See LICENSE for more information.

https://github.com/cameronabrams

Contributing

1. Fork it (https://github.com/cameronabrams/sandlercubics/fork)
2. Create your feature branch (git checkout -b feature/fooBar)
3. Commit your changes (git commit -am 'Add some fooBar')
4. Push to the branch (git push origin feature/fooBar)
5. Create a new Pull Request