Kinetics of thiophene hydrodesulfurization over a supported Mo–Co–Ni catalyst

Abstract

In this study, the kinetics of thiophene (TH) hydrodesulfurization (HDS) over the MoeCo eNi-supported catalyst was investigated. Trimetallic catalyst was synthesized by pore volume impregnation and the metal loadings were 11.5 wt % Mo, 2 wt % Co, and 2 wt % Ni. A large surface area of 243 m 2 /g and a relatively large pore volume of 0.34 cm 3 /g for the fresh MoeCoeNi-supported catalyst indicate a good accessibility to the catalytic centers for the HDS reaction. The acid strength distribution of the fresh and spent catalysts, as well as for the support, was determined by thermal desorption of diethylamine (DEA) with increase in temperature from 20 to 600 C. The weak acid centers are obtained within a temperature range between 160 and 300 C, followed by medium acid sites up to 440 C. The strong acid centers are revealed above 440 C. We found a higher content of weak acid centers for fresh and spent catalysts as well as alumina as compared to medium and strong acid sites. The catalyst stability in terms of conversion as a function of time on stream in a fixed bed flow reactor was examined and almost no loss in the catalyst activity was observed. Consequently, this fact demonstrated superior activity of the MoeCoeNi-based catalyst for TH HDS. The activity tests by varying the temperature from 200 to 275 C and pressure from 30 to 60 bar with various space velocities of 1e4 h À1 were investigated. A LangmuireHinshelwood model was used to analyze the kinetic data and to derive activation energy and adsorption parameters for TH HDS. The effect of temperature, pressure, and liquid hourly space velocity on the TH HDS activity was studied.

Effect of Support on the Performance of CoMoRe Catalyst in Thiophene and Benzothiophene Hydrodesulfurization

“…The catalytic tests have been performed in a standard fixed bed reactor, described in our previous work [1]. The feedstock consisted of 0.625 wt% thiophene (or 1 wt% benzothiophene) solution in hexane, was used to simulate a FCC gasoline with a sulphur concentration of 2380 ppm.…”

“…Sulfur bonded to various organic species present in fuels is thus converted to H 2 S, which is eliminated and then converted to elemental sulfur through the Claus process. The concern for improving the performance of hydrodesulfurization catalysts is found in the large number of published papers that address this process [1][2][3][4][5][6][7].…”

Hydrodesulphurization of Thiophenes over CoMoRe/ ZSM 5gama-Al2O3 Catalyst

“…The catalyst was activated in a fixed bed reactor using hydrogen stream (electrolytic hydrogen purity from Linde Company) with a flow rate of 15 L/h at 450°C for 6 h. The activity of Co-Mo-Re/γ-Al 2 O 3 -Zn-HZSM5 catalyst was determined in the same reactor used in other studies [12,13] under isothermal conditions. An amount of 40 cm 3 catalyst was loaded in the middle of the reactor and the top and the bottom of the reactor were filled with inert glass beads with the average diameter of 1-2 mm.…”

Accelerating Kinetic Parameter Identification by Extracting Information from Transient Data: A Hydroprocessing Study Case

“…Hydroprocessing kinetic modeling is a challenging and time-consuming task as the crude oils contain many compounds with complicated structures [6]. Diverse approaches for hydroprocessing modeling have been developed in the past such as the lumping technique [7][8][9][10][11][12], detailed kinetic modeling [13][14][15][16][17][18][19], and black-box approach [20][21][22][23]. The lumping technique, which consists of regrouping chemical compounds with similar properties, is the most common and widely used [24].…”