Optimization of γ-Alumina porosity via Response Surface Methodology: The influence of engineering support on the performance of a residual oil hydrotreating catalyst

Abstract

As is evident in the literature, co-precipitation process has been narrowly studied from the "process" point of view thus far, and consequently majority of this complex phenomenon remains unknown scientifically. This work firstly tries to screen in depth the synthesis procedure of γ-Alumina in terms of precipitation, whereas such key parameters governing this process as temperature, reactant concentrations, mixing rate, and aging time are thoroughly analyzed by using Response surface methodology (RSM) for the very first time. Considering some significant novel interactions between these variables, the porosity of the final materials in terms of Specific Surface Area (SSA), Total Pore Volume (TPV), and Mean Pore Diameter (MPD) could be adjusted without using any surfactant or other additional organic compounds. For instance, simultaneous enhancement in SSA, TPV, and MPD, respectively, up to 334.5 m2. g−1, 1.93 cm3.g−1, and 23.01 nm with a narrow pore size distribution were achieved only by adjusting the process variables which have not been reported ever before. Two optimized materials suggested by Central Composite Design (CCD) were reproduced, analyzed by using such techniques as XRD, FT-IR, BET, SEM, and TG analyses and then used to prepare final Hydrotreating (HDT) catalyst for application in a trickle bed continuous hydrotreater.