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.
Highlights
Crude oils contain a significant number of extremely poor-quality heavy compounds
An activated carbon-supported catalyst (NiMo/AC) exhibits higher conversions compared to the silica-supported catalyst, but lower conversions than that of alumina-supported catalyst
Hydrotreating catalysts were prepared with silica, activated carbon, and mesoporous alumina supports and tested for vacuum residue hydrotreating reactions at 410 ◦ C temperature and 10 MPa pressure
Summary
There is a worldwide demand for low-sulfur, improved quality fuel oils and feedstocks for fluid catalytic cracking (FCC), and hydrocracking is continually increasing, while the available heavy crudes are becoming heavier [1,2,3]. The heaviest cuts, known as vacuum residues, contain a large amount of impurities such as metals, nitrogen, sulfur, and polyaromatic compounds. These are characterized as boiling above 550 ◦ C, having high viscosity and specific gravity, and having high carbon residues and asphaltenes [1,2,3,4]. The presence of high molecular weight polyaromatic compounds and impurities in residues makes the upgrading of these feedstocks very difficult compared to lighter feeds
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
