Effect of Silica, Activated Carbon, and Alumina Supports on NiMo Catalysts for Residue Upgrading

Abstract

The effect of different supports such as silica (SBA-15), activated carbon (AC), and mesoporous alumina (Al2O3) on catalytic activities of hydrotreating nickel molybdenum (NiMo) catalysts was demonstrated for upgrading vacuum residue. Nitrogen adsorption-desorption analysis showed that SBA-15 and the AC-supported NiMo catalyst possessed a very high surface area compared to the alumina-supported catalyst. However, NiMo/Al2O3 catalyst possesses a higher pore diameter and pore volume with an appropriate surface area. X-ray diffraction (XRD) analysis showed that active metals were dispersed in the catalytic supports. Transmission electron microscopy (TEM) analysis revealed the presence of type II active MoS2 sites in the NiMo/Al2O3 catalyst, which showed weak metal-support interactions having a high intrinsic activity. Catalyst activities such as hydrodesulfurization (HDS), hydrodemetallization (HDM) and asphaltene conversion (HDAs), and hydrocracking conversions of a vacuum residue were evaluated. The highest hydrotreating and hydrocracking conversions were observed with the NiMo catalyst supported on mesoporous alumina. The results also supported that the catalyst that has a large pore diameter, high pore volume, and better active metals dispersion is highly desirable for the upgrading of a vacuum residue.

Production of cleaner waste tire pyrolysis oil by removal of polycyclic aromatic hydrocarbons via hydrogenation over Ni‐based catalysts

“…This possibly resulted from the effect of catalyst acidity and the reaction condition (high temperature and H 2 pressure). Kohli et al 60 reported that the alumina support could promote the cracking of residue and VGO during the hydrotreating of the vacuum residue. However, no difference in product distribution obtained from the system using NiMo/γ‐Al 2 O 3 catalyst or NiW/γ‐Al 2 O 3 catalyst was observed, although the acidity of both catalysts was different.…”

Effectiveness Study of Mesoporous Size, Acidity, and Precursor Type on Characterization of Activated Carbon as an Fe–Mo Catalyst Support for Hydrodesulfurization of Heavy Naphtha

“…These peaks can be attributed to MoO 2 or MoO 3 phases. 19 Overall, FeMocit-AC2 and FeMo-cit-TAC2 products show broad peaks with lower intensity indicating that their particle sizes are relatively small and there is substantial dispersion of active metal particles in the structure. When the metal particles spread more evenly, it is expected that agglomeration of the particles reduces leading to smaller particle sizes.…”

“…For instance, Kohli et al have studied the effects of various types of supports such as alumina, activated carbon, and silica on the performance of Ni–Mo catalysts for residue upgrading. Having found that the alumina support results in higher sulfur removal yield, they determined that the size and volume of the pores are directly related to the performance of the catalyst . In another work, the performance of the same catalyst for removing thiophene was studied by trying various types of support materials .…”

“…18 Conversely, there are pieces of evidence showing that catalysts synthesized on an alumina support lead to higher efficiency in sulfur removal operations. For instance, Kohli et al 19 have studied the effects of various types of supports such as alumina, activated carbon, and silica on the performance of Ni− Mo catalysts for residue upgrading. Having found that the alumina support results in higher sulfur removal yield, they determined that the size and volume of the pores are directly related to the performance of the catalyst.…”

“…Having found that the alumina support results in higher sulfur removal yield, they determined that the size and volume of the pores are directly related to the performance of the catalyst. 19 In another work, the performance of the same catalyst for removing thiophene was studied by trying various types of support materials. 20 The highest removal percentage was found for the alumina-support catalyst and was attributed to the higher acidity of the surface compared to other studied supports.…”