Simulation of solvent extraction of South African vitrinite- and inertinite-rich coals

The application of molecular simulation and visualization approaches to solvent extraction was evaluated with large-scale molecular models (>14000 atoms) of vitrinite- and inertinite-rich coals. A theoretical extraction yield was determined for the proposed molecular models using a molecule-specific solubility parameters approach. The theoretical extraction yields for these models agreed with the experimental trends. While this novel solubility estimation method did not predict the exact extraction yield of these models, there was agreement with extraction trends. Residue and extracted models were generated from the large-scale molecular coal models using solubility parameters and showed agreement with laser desorption-ionization time-of-flight mass spectrometry (LDTOF-MS) data. Thus, solvent extraction trends can be used to test the applicability of large-scale coal molecular models.