Tools  |  Online calculators developed by the EgiChem Group

Estimation of diffusivities in polar and nonpolar systems

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Notes:

This tool estimates the binary diffusivity of a solute in polar (except water) and nonpolar (except supercritical carbon dioxide) solvents. It uses machine learning models trained with over 2500 experimental data points from over 150 systems.

Quickstart

Select the program and provide the properties using their flags.

Solvent Program Required properties (unit) [-flag]
Polar ml_polar.py Temperature (K) [-t]
Viscosity (cP) [-v]
Solute Molar Mass (g/mol) [-m2]
Solute Critical Pressure (bar) [-cp2]
Solvent Molar Mass (g/mol) [-m1]
Solvent Lennard-Jones Energy (K) -[e1]
Nonpolar ml_nonpolar.py Temperature (K) [-t]
Viscosity (cP) [-v]
Solute Molar Mass (g/mol) [-m2]
Solute Critical Pressure (bar) [-cp2]
Solvent Molar Mass (g/mol) [-m1]

Example:

python ml_scco2.py -t 313.15 -d 0.830000647 -mm 430.71 -cp 8.45543 -af 0.8071

# Output:
# Predicted diffusivities:
# D12(1) = 5.81821846E-05 cm2/s

You can also calculate multiple points by providing the properties as a CSV file. See below.

Requirements

Python 3 and the following Python libraries are required:

  • numpy
  • pandas
  • scikit-learn
  • joblib

Program is fully tested on:

  • Python 3.7
  • numpy 1.18.5
  • pandas 1.0.5
  • scikit-learn 0.23.1

Installation

  1. Install Python from python.org.
  2. Download the software by clickig Code >> Download ZIP.
  3. Unpack the zip file.
  4. Open the command line and run pip install -r requirements.txt to install the required libraries.
  5. You can now cd to the program folder and use it as described below.

Usage

Option 1) By providing the properties in order:

Call the program you desire and provide the properties in order. For istance, for the SC-CO2 program:

  1. Temperature (K)
  2. Density (g/cm3)
  3. Solute molecular mass (g/mol)
  4. Solute critical pressure (bar)
  5. Solute acentric factor (-)
python ml_scco2.py --properties YOUR_TEMPERATURE YOUR_DENSITY YOUR_MOLECULAR_MASS YOUR_CRITICAL_PRESSURE YOUR_ACENTRIC_FACTOR

Example:

python ml_scco2.py --properties 313.15 0.830000647 430.71 8.45543 0.8071

# Output:
# Predicted diffusivities:
# D12(1) = 5.81821846E-05 cm2/s

Option 2) By specifying each property:

In this case the order is irrelevant.

python ml_scco2.py --temperature YOUR_TEMPERATURE --density YOUR_DENSITY --molecularmass YOUR_MOLECULAR_MASS --criticalpressure YOUR_CRITICAL_PRESSURE --acentricfactor YOUR_ACENTRIC_FACTOR

# OR using 

python ml_scco2.py -t YOUR_TEMPERATURE -d YOUR_DENSITY -mm YOUR_MOLECULAR_MASS -cp YOUR_CRITICAL_PRESSURE -af YOUR_ACENTRIC_FACTOR

Example:

python ml_scco2.py -t 313.15 -d 0.830000647 -mm 430.71 -cp 8.45543 -af 0.8071

# Output:
# Predicted diffusivities:
# D12(1) = 5.81821846E-05 cm2/s

Option 3) By specifying a CSV file with the input data:

The CSV file must include at least five columns with the following headers:

Case SC-CO2 Polar Nonpolar
Properties/Headers T
density
solute.M2
solute.Pc
solute.w		 T
viscosity
solute.M2
solute.Pc
solvent.M1
solvent.elj		 T
viscosity
solute.M2
solute.Pc
solvent.M1

You can provide any number of points as rows. See the examples folder.

python ml_scco2.py --csvfile YOUR_CSVFILE_PATH

Example:

# Using a file in the same directory with 3 points (rows)
python ml_scco2.py --csvfile sample-scco2-data.csv

# Output:
# Predicted diffusivities:
# D12(1) = 5.03732712E-05 cm2/s
# D12(2) = 1.05026748E-04 cm2/s
# D12(3) = 9.14913157E-05 cm2/s

Save results

Optionally you can use the --save or -s flag to save the results in an csv file.

python ml_scco2.py --csvfile YOUR_CSVFILE_PATH --save

Help

python ml_scco2.py -h

Citing

If you use the SC-CO2 program for a scientific publication please cite: