Enhancement of hydrotreating process evaluation: correlation between feedstock properties, in-line monitoring and catalyst deactivation

During middle distillates hydroprocessing, the relationship between feed properties, operating conditions and the deactivation phenomenon is crucial to achieve fuels specification. In this work, an accelerated deactivation methodology was employed to in short periods observe and study the deactivation phenomenon. For the stabilization step, 100 h of run were necessary to guarantee that the initial deactivation was achieved. Easy, versatile, and portable tools were employed successfully to monitor and evaluate the hydrotreating process in line, as Fourier Transform Infrared (FTIR) analysis together with density measurements. Besides, process modifications related to hydrotreating reactions were identified using FTIR and it was confirmed that feedstock properties may directly influence the deactivation phenomenon. The feedstock with higher aromatics and olefins concentration required increasing the temperature to 420 °C and the lower H2/oil ratio (150 std m3/m3) to reduce desulfurization and hydrogenation reaction activities by coke formation and deposition.