Desulphurisation of dibenzothiophene and 4,6–dimethyl dibenzothiophene via enhanced hydrogenation reaction route using RePd–TiO2/SiO2 aerogel catalysts: kinetic parameters estimation and modelling
Re/Pd-TiO2/SiO2 aerogel catalysts were synthesized by using a sol-gel method and supercritical drying in excess solvent and investigated in the reaction of hydrodesulphurisation (HDS) of dibenzothiophene (DBT) and 4,6-dimethyl dibenzothiophene (4,6-DMDBT). Both Re/Pd catalysts, obtained wit...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Association of Chemical Engineers of Serbia
2022-01-01
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| Series: | Hemijska Industrija |
| Subjects: | |
| Online Access: | http://www.doiserbia.nb.rs/img/doi/0367-598X/2022/0367-598X2203135P.pdf |
| Summary: | Re/Pd-TiO2/SiO2 aerogel catalysts were synthesized by using a sol-gel method
and supercritical drying in excess solvent and investigated in the reaction
of hydrodesulphurisation (HDS) of dibenzothiophene (DBT) and 4,6-dimethyl
dibenzothiophene (4,6-DMDBT). Both Re/Pd catalysts, obtained with and
without the use of mesitylene in the synthesis step, have shown increased
conversions of up to 70 % in the desulphurization of 4,6-DMDBT, when
compared to conventional Co/Mo hydroprocessing catalysts. This observation
is of importance for conversion of highly refractory 4,6-DMDBT and
hydroprocessing to produce ultra-low sulphur diesel fuels, ULSD. In order to
quantify the extent of desulphurisation, which proceeds via a hydrogenation
route, conversions of DBT and 4,6-DMDBT along with evolution of reaction
products characteristic for the direct desulphurisation route and the
hydrogenation route were monitored by using a gas chromatography–mass
spectrometry (GC-MS) analytical technique. The reaction was performed at 630
K and 6 MPa in a batch catalytic reactor. The experimental results were used
in the Hougen-Watson kinetic model describing DBT and 4,6-DMDBT
desulphurisation on σ and τ active sites. Kinetic parameters of this complex
catalytic kinetics were determined by using a Genetic Algorithm method and
minimum deviation function. Values of calculated kinetic parameters and
values of the ratio of 3-methylcyclohexyltoluene (MCHT and dimethyl biphenyl
(DMBPH) expressed as the MCHT/(MCHT+DMBPH) ratio ranging between 0.66 and
0.94, have confirmed that the hydrogenation route is the dominant route for
desulphurisation of 4,6-DMDBT. |
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| ISSN: | 0367-598X 2217-7426 |