Predicting both lower and upper flammability limits for fuel mixtures from molecular structures with same descriptors

Knowledge of flammability limits values, including both the lower flammability limit (LFL) and upper flammability limit (UFL), is essential to maximise safety in process design and operational procedures. This study aims to develop theoretical models for predicting both lower and upper flammability limits for fuel mixtures from molecular structures with the same molecular descriptors. All samples were collected from a single reference and the “compounds out” strategy was employed to divide the training and the test set. Descriptors for pure compounds were calculated by Gaussian 16 and Multiwfn package. The developed LFL and UFL models were validated with rigorous internal and external validations. The results indicated the robustness, validity, and satisfactory predictivity of the established models. The applicability domain (AD) of the model was also defined. The established LFL and UFL models demonstrated that the higher dipole moment and van der Waals volume are, the higher LFL and lower UFL values are. The proposed models can be expected to predict the LFL and UFL values for other fuel mixtures for which experiment values are unknown, only based on molecular structures.