(544ek) Oxidative Desulfurization of Diesel Fuel Using Vanadium Supported Catalyst on Titanium Nanotube

Authors: 
Dehghani, M. R., Iran University of Science and Technology
Banisharif, F., Iran University of Science and Technology
Ranjbar, N., Iran University of Science and Technology

Oxidative Desulfurization of Diesel Fuel
Using Vanadium Supported Catalyst on Titanium Nanotube

N. Ranjbar Motlagh, M.R. Dehghani, F.
Banisharif

Chemical Engineering Department, Iran
University of Science and Technology, Narmak, Tehran, Iran

Abstract

In order to meet the approved sulfur emission standards, it
is necessary to develop alternative methods for deep desulfurization of fuels
and petroleum fractions. In this work, oxidative desulfurization (ODS) of
benzothiophenic compounds (benzothiophene (DBT) and dibenzothiophene (BT)
prevailing in diesel was conducted with 30 wt% hydrogen peroxide in presence of
various catalysts at mild conditions (atmospheric pressure and temperature lower
than 100 °C), using a model diesel (sulfur content of 1000 ppmw). ODS
activities of sulfur compounds in n-heptane for a series of V2O5
catalysts supported functionalized multi walled carbon nanotubes (FMWCNT) was
evaluated. The synthesized support and catalyst were characterized by FT-IR,
Raman Spectroscopy, XRD, FE-SEM, BET and H2-TPR methods. The effect
V2O5 loading percentage (7, 14, 20 wt. %) on the ODS
performance of vanadia titanium oxide nanotube (TNT) was examined. The results
showed that %20 V2O5/TNT  (VT-20)
catalyst had maximum catalytic
activity within 1 hour (Table 1). The results revealed that the activity
of catalyst was increased by increase in vanadium loading percentage. The
comparison between the activity in 30 minute and 60 minute showed that the all
catalysts has been converged to their maximum activity after 30 minutes.

The kinetic model study of VT-20 states that the degree of
ODS reaction is one (Figure 1). The reaction constant was also determined
0.1037 min-1.

Table 1. Oxidative Desulfurization performance of titanium oxide nanotube supported vanadia catalysts (Initial sulfur content: 1000 ppmw, initial DBT content: 500 ppmw, initial BT content: 500 ppmw, T= 45 oC, mole ratio of oxygen to sulfur containing compound: 4, solvent (acetonitrile) to oil volume ratio: 0.5, rpm: 1000)

Type Catalyst

15 min

30 min

60 min

Total S Removal %

BT Removal %

DBT Removal %

Total S Removal %

BT Removal %

DBT Removal %

Total S Removal %

BT Removal %

DBT Removal %

VT-7

59.2

49

69.4

89.4

88.6

90.2

91

90.4

91.6

VT-14

63

53.6

72.4

92.1

90.4

93.8

93.2

91.4

95

VT-20

73.5

66.4

80.6

96.2

95

97.4

96.7

95.6

97.8

 

Ln(initial concentration sulfur/ final concentration sulfur)

 

Time (min)

Figure 1. Kinetic study of sulfur removal by optimum catalyst (Initial sulfur content: 1000 ppmw, T= 45 oC, mole ratio of oxygen to sulfur containing compound: 4, solvent (acetonitrile) to oil volume ratio: 0.5, rpm: 1000)

Keywords:
Oxidative desulfurization, Diesel
fuel, V2O5 supported catalysts, Multi walled carbon nanotube

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