Energy, Chemical Engineering, Software, Mechanical Engineering
11
Scopus Publications
Scopus Publications
Flash point behavior of multicomponent terpene mixtures: An experimental and modeling study Sérgio M. Vilas-Boas, Fernanda Sossai Altoé, Eduardo de Souza Esperança, Filipe Hobi Bordón Sosa, Débora Costa do Nascimento, Antonio M. Barbosa Neto, Mariana Conceição da Costa Process Safety and Environmental Protection, 2026 The flash point (FP) is a critical property for assessing fire and explosion hazards of flammable liquids. However, reliable FP data for terpene-rich mixtures are scarce, despite their relevance as the major constituents of commercial essential oils. This work provides a comprehensive investigation of the FP behavior of four naturally abundant monoterpenoids— p -cymene, linalool, carvacrol, and eugenol—and their binary and ternary mixtures. Experimental measurements were performed using the ASTM D6450 closed-cup procedure, revealing a quasi-linear relationship between the FP and the normal boiling point for the pure compounds. The mixtures, however, exhibited complex structure-property relationships, where specific intermolecular interactions play a key role in the FP behavior. To complement the experimental studies, the predictive capabilities of the Liaw-UNIFAC and COSMO-RS models were benchmarked against the ideal approach for the mixtures. COSMO-RS provided the best overall representation, with a global RMSE of 0.9 K. The Liaw-UNIFAC (global RMSE = 2.9 K) outperformed the ideal approach (RMSE = 3.6 K) in six of the ten mixtures studied, highlighting that its performance is highly system-dependent. This work delivers crucial experimental data and validates a modeling framework for assessing the FP of multicomponent monoterpene mixtures, providing valuable insights for process safety and fire risk assessment in the EO industry.
Gas Hydrate Formation with Protic Ionic Liquids under Multiphase Flow Conditions Débora Costa do Nascimento, Conrado Chiarello, Antonio Marinho Barbosa Neto, Amadeu K. Sum, Mariana Conceição da Costa Energy and Fuels, 2025 High Resolution Image Download MS PowerPoint Slide Gas hydrates are nonstoichiometric solid solutions formed by water and gas. They are formed under high-pressure and low-temperature conditions, which are prevalent in deep-water offshore oil and gas extraction operations. The formation of hydrates during production can lead to flowline obstruction and damage to pipes, fittings, and valves, which can ultimately cause line rupture. Therefore, in the oil/gas industry, the risk associated with hydrates must be minimized by either avoiding formation or at least managing it. Alternative solvents such as ionic liquids (ILs) have been extensively tested as thermodynamic or kinetic hydrate inhibitors in the past decade in stirring cells or rocking cells. Protic ionic liquids (PILs), however, have been overlooked. Hydrate formation in the presence of ILs under conditions closer to the actual flowline environment and the concomitance of an oil phase have also been neglected in the published literature. As such, the aim of this study is to assess methane hydrate formation and dissociation in the presence of PILs obtained from precursors ethanolamines and short-chain organic acids, which act as thermodynamic inhibitors. The efficiency of such compounds as gas hydrate inhibitors was studied by using a rock-flow cell apparatus with aqueous solutions containing 10 wt % PIL in systems with and without mineral oil. It was possible to check for the formation of plugs or bed of hydrates and observe slurry instability, pressure/temperature profiles, and water conversion in both scenarios. Surface and interface tensions were also accounted for.
