Air-Separation

This project simulates an air separation (oxygen production) plant by orchestrating a PRO/II process simulation via Python (COM automation). It enables data extraction, sensitivity analysis, and optimization of key operating variables.

For background and methodology, see: First Paper and Second Paper.

Repository structure

• Air_Separation.py: Main script. Connects to PRO/II via COM, copies a source .prz to a working file, sets inputs, runs calculations, and computes KPIs/CAPEX/OPEX.
• cost_utils.py: Cost calculation helpers (compressors, expanders, towers, trays, HX, MSHE, pump, ASU scaling).
• Casebook_Air_Separation_Plant.prz: PRO/II casebook (project) file used by the script.
• Casebook_Air_Separation_Plant.inp: PRO/II input file imported by the script.
• A8_Air_Separation_Plant.prz, Air_Separation_Bryan.prz: Additional PRO/II project variants (optional/legacy).
• Readme.md: Project documentation.

Prerequisites

• Windows OS (COM automation)
• Installed and licensed PRO/II (tested with SimSci/AVEVA PRO/II; ensure the Database COM server SimSciDbs.Database.102 is available)
• Python 3.8+ on Windows
• Python packages: pywin32, numpy

Install Python dependencies:

pip install pywin32 numpy

Usage

1. Ensure PRO/II is installed and you can open Casebook_Air_Separation_Plant.prz manually.
2. Set the source project path inside Air_Separation.py (variable db_path_origin). Example:

   db_path_origin = r"D:\\Bryan\\ESPOL\\Model_HR_3CDN.prz"

   The script copies this file to the current working directory as Working_file.prz and runs the simulation on that working copy.
3. Run the script from PowerShell or CMD:

   python Air_Separation.py

4. The script will:
   • Initialize the PRO/II COM server
   • Import the .inp corresponding to the working .prz
   • Open the working database Working_file.prz
   • Acquire a security seat
   • Apply input changes (HX temps/liquid fractions, column pressure/reflux, ARG duty)
   • Run calculations and generate a report
   • Compute recoveries, duties, equipment costs (via cost_utils.py), CAPEX and OPEX
   • Release the security seat and close

Output artifacts (report files) are generated by PRO/II in the same directory as the project unless configured otherwise.

Configuration notes

• If your PRO/II installation registers a different COM ProgID (e.g., SimSciDbs.Database.110), update the dispatch string in Air_Separation.py:

  win32.Dispatch("SimSciDbs.Database.110")

• The script imports the .inp that shares the same stem as the working .prz (e.g., Working_file.inp). Ensure the .inp is available or adjust the import line if needed.
• Costs are computed using functions in cost_utils.py. You can modify factor choices (e.g., FM) or unit assumptions there.

Extending: Sensitivity and optimization

The repository includes the basic wiring to control and query PRO/II. To add sensitivity analysis and optimization:

• Identify decision variables and KPIs via ActivateObject(...).Get/SetAttribute* APIs
• Loop over variable grids or use an optimizer (e.g., scipy, nevergrad) to call RunCalcs and record KPIs
• Persist results to CSV/Parquet and visualize with matplotlib/seaborn

Troubleshooting

• COM dispatch fails: verify PRO/II is installed and the COM server ProgID matches. Run Python as Administrator if needed.
• License/seat errors: ensure you have available PRO/II licenses; the script requests a security seat (GetSecuritySeat(2)).
• File not found: check db_path and that .prz and .inp are accessible.

Citation

If you use this repository, please cite the associated work (see the paper linked above).