Chemical process simulation underpins modern chemical plant design, by enabling optimization of sustainability, yield, and economics. However, the prohibitive cost of commercial software suites limits early-stage evaluations. We demonstrate DWSIM, an open-source simulator with a graphical user interface comparable to commercial platforms, as a viable alternative for lignocellulosic biorefinery  through two case studies: (i) an ethanol organosolv plant using rectification for solvent recovery, and (ii), a γ-valerolactone (GVL) process employing liquid-liquid extraction with toluene, followed by heteroazeotropic distillation of the water/GVL/toluene system.

The files "Ethanol_Design" and "GVL_Design" contain the respective DWSIM simulation files, designed to process 100 t/h corn stover. The digestor and liquid regulators were implemented in Python. Custom compounds (solid cellulose, dissolved cellulose, solid hemicellulose, dissolved hemicellulose, solid lignin, dissolved lignin, "others" (undefined biomass compounds, to complete the mass balance), sulfuric acid, and GVL) are provided as .json files. The "NRTL_uncertainty" file can be used to perfom Monte Carlo uncertainty analysis of the NRTL parameters in the model. Before running, change the path for the log files and output!

Furthermore, "xml_to_table.py" is provided which can be used to reformate DWSIM's xml output into spreadsheet-ready table format. To use: export the DWSIM report (DWSIM/Results/Create Report). Make sure the "Material Streams" checkbox is checked, and that the "Include conditions", "Include Molar Composition" and "include Mixture Properties" boxes are all checked under "Options". Then select "Export data to file", and save the report as "Data.xml". Then run xml_to_table.py, which creates a .csv that can be imported into Excel.