Comparison of γ and δ-Al2O3 supported CoMo catalysts in the hydrodesulfurization of straight-run gas oil

Abstract

The e ect of two di erent crystal species of alumina on the hydrodesulfurization activity of the corresponding CoMo catalysts was studied. Cylindrical extruded alumina with two di erent crystal structures, i.e., -Al2O3 and -Al2O3, was prepared using boehmite and nitric acid as a peptizing agent by calcination at 550 C and 900 C, respectively. Al2O3 supports were impregnated with 9 wt.% of Mo and 2 wt.% Co by an incipient wetness impregnation method. CoMo/Al 2 O 3 catalysts were used for hydrodesulfurization (HDS) and hydrodenitri cation (HDN) of Iranian Straight-Run Gas Oil (ISRGO). The supports and catalysts were characterized by nitrogen adsorptiondesorption isotherm, XRD, UV-vis-DRS, TPD, TPR, CO chemisorption, and ICP-OES. The HDS activity of CoMo/ -Al2O3 catalyst was higher than that of CoMo/ -Al2O3 and was found to be 95.74%. This result was obtained from the formation of larger CoMoO 4 and MoO 3 crystals in CoMo/ -Al 2 O 3 catalyst, thus reducing the active metal phase dispersion and the performance of the catalyst. The HDS activity of CoMo/ -Al2O3 catalyst was remarkable as the metal content of the catalyst was low. The HDN activity of CoMo/ -Al2O3 was also about 66%.

A Mechanistic Study of Layered-Double Hydroxide (LDH)-Derived Nickel-Enriched Mixed Oxide (Ni-MMO) in Ultradispersed Catalytic Pyrolysis of Heavy Oil and Related Petroleum Coke Formation

“…It is worth noting that A typical HDS CoMo-(γ)alumina catalyst with a similar surface area to the one used in these experiments at 204.24 m 2 /g was shown to have an acid site density of 1.5134 mmol/g. 17 The significant difference in acidity between the prepared and refinery catalyst is influenced by the alumina support. This has been shown to heavily influence catalyst acidity and promote coke-generating reactions in previous work.…”

Comparative Study on the Hydrogenation of Naphthalene over Both Al2O3-Supported Pd and NiMo Catalysts against a Novel LDH-Derived Ni-MMO-Supported Mo Catalyst

“…The Pd 2% /Al 2 O 3 and Pd 5% /Al 2 O 3 catalysts exhibited a low-intensity broad peak ranging from 100 to 900 °C, while the latter comprised a small peak at 744 °C. For comparison, a γ-alumina catalyst bearing molybdenum, promoted by cobalt, exhibits a total acid site count of 1.513 mmol g –1 when using NH 3 as the adsorption agent …”

“…For comparison, a γalumina catalyst bearing molybdenum, promoted by cobalt, exhibits a total acid site count of 1.513 mmol g −1 when using NH 3 as the adsorption agent. 41 3.1.5. Morphology and Metallic Distribution.…”

Recent Advances and Challenges in Developing Technological Methods Assisting Oxidative Desulfurization of Liquid Fuels: A Review

“…Various forms of sulfur exist in petroleum, including thiophene (Th), benzothiophene (BT), dibenzothiophene (DBT), benzonaphthothiophene (BNT), 4,6-dimethyl dibenzothiophene (4,6-DMDBT), disulfides, sulfides, and mercaptans . Hydrodesulfurization (HDS), , extractive desulfurization (EDS), oxidative desulfurization (ODS), , adsorptive desulfurization (ADS), biodesulfurization (BDS), and supercritical water desulfurization (SWDS) have been employed to decrease sulfur content in liquid fossil fuels. The HDS method as a traditional technology presents several shortcomings, such as hydrogen requirement, high temperature and pressure, and high cost. , The mild operating conditions of ODS (atmospheric pressure and relatively low temperature) make it one of the most promising and economic processes. , The oxidative desulfurization process involves chemical reaction between an oxidizing agent and sulfur-containing compounds with/without catalyst at atmospheric pressure and relatively low temperature. , By using polar solvents or adsorbents, the obtained compounds (sulfones/sulfoxides) can be removed from the fuel.…”