2018 AIChE Annual Meeting

(544er) Oxidative Desulfurization of Thiophenic Components By Vanadium Substituted Dawson-Type Polyoxometalate Supported Catalysts

Authors

Dehghani, M. R. - Presenter, Iran University of Science and Technology
Banisharif, F., Iran University of Science and Technology
Khomartaji, M. N., Iran University of Science and Technology

Oxidative Desulfurization of Thiophenic Components by
Vanadium substituted Dawson-type Polyoxometalate Supported Catalysts

M. Naderi Khomartaji, M. R. Dehghani, F.
Banisharif

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

Abstract:                            

In this work, a new supported catalysts for oxidative
desulfurization (ODS) of thiophenic sulfur compound (dibenzothiophene (DBT) and
benzothiophene (BT)) were synthesized by using on vanadium substituted
Dawson-type heteropoly acid, H6+xP2W18-xVxO62
(x= 1, 3, 5) and silica and titania as a support. The effect of heteropoly acid
loading on the Support (5, 15, 25 wt. %) as well as number of vanadium
substitution on ODS performance of all catalysts was studied. The result showed
that the 25 wt.% H9P2W15V3O62/TiO2
is the best one among all synthesized catalyst. The activity of titania
supported catalyst was more than silica supported catalysts. The result
obtained in this work is similar to work of Yan et al [1, 2]. The activity of
catalysts by increase in number of vanadium from 3 to 5 were decreased. It can
be because of increase in instability of polyoxometalate cage by increase in
number of vanadium [3]. The best catalyst was characterized using XRD, FT-IR
and UV spectrophotometry and polyoxometalic structure were proved. The
synthesized catalyst were utilized for oxidative desulfurization, after 20
minute following results obtained in different cases.


Dibenzothiophene Removal (%)

Benzothiophene Removal (%)

68.75

50

81025

58.75

61.75

53.13

59.375

87.5

65.63

97.88

93.94

63.75

86.56

56.25

93.38

58.75

81.88

53.13

87.5

59.38

95.63

61.25

96.25

62.5

91.88

62.2

95.06

68.75

98.75

78.13

74.38

51.56

75

54.7

87.5

70.3

Table 1. Oxidative desulfurization of model oil: T= 60 oC, catalyst dosage= 10 g/L, Oxygen to sulfur content oil ratio=4, t= 20 min

Model oil containing both 500 ppmw BT and 500 ppmw DBT in n-Octane

Catalyst

5 wt.% H7P2W17VO62/SiO2

15 wt.% H7P2W17VO62/SiO2

25 wt.% H7P2W17VO62/SiO2

5 wt.% H9P2W15V3O62/SiO2

15 wt.% H9P2W15V3O62/SiO2

25 wt.% H9P2W15V3O62/SiO2

5 wt.% H11P2W15V5O62/SiO2

15 wt.% H11P2W15V5O62/SiO2

25 wt.% H11P2W15V5O62/SiO2

5 wt.% H7P2W17VO62/TiO2

15 wt.% H7P2W17VO62/TiO2

25 wt.% H7P2W17VO62/TiO2

5 wt.% H9P2W15V3O62/TiO2

15 wt.% H9P2W15V3O62/TiO2

25 wt.% H9P2W15V3O62/TiO2

5 wt.% H11P2W15V5O62/TiO2

15 wt.% H11P2W15V5O62/TiO2

25 wt.% H11P2W15V5O62/TiO2

Keywords: Oxidative
Desulfurization, Thiophenic Component, Dawson Polyoxomatalate

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[2] Yan, X.M, Lei.J, Liu.D, Wu.Y, Liu.W., Synthesis and
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oxidative dehydrogenation of isobutyric acid. Catalysis Communications, 2008.
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