Modeling polycyclic aromatic hydrocarbons (PAH) and liquid organic hydrogen carriers (LOHC) with the SAFT-γ Mie group-contribution equation of state

Liquid organic hydrogen carriers (LOHC) are being studied as a promising and feasible alternative for hydrogen storage and transportation due to their high hydrogen uptake capacity, low flammability, and stability at ambient conditions. This work focuses on expanding the applications of the SAFT-γ Mie group-contribution equation of state by estimating the parameters of two new groups: an aromatic bridgehead carbon (aC), and a methylene “elbow” group connecting two aromatic rings (aCCH 2 aC), starting from readily available experimental data on polyaromatic hydrocarbons (PAH) and LOHC candidates such as alkylcarbazoles, diphenylmethane, and isomers of benzyl- and dibenzyltoluene. The model describes with good accuracy the vapor pressure and saturated liquid density of these substances, with a % A A D P v a p o v e r a l l of 9.67%, and a % A A D ρ l i q o v e r a l l of 0.82%, as well as the vapor-liquid equilibria of PAH + long-chain alkane mixtures, but has some limitations when describing the structural nuances of molecules that present the same functional groups. As a result, second-order interaction parameters are proposed to improve the correlation of the calculated and experimental data.