OP-II-3

OP-III-B-12HYDRODESULFURIZATION OF 4,6-DIMETHYLDIBENZOTHIOPHENEON NiMoP/Al 2 O 3 CATALYST IN A TRICKLE BED MICROREACTORGarcía-Martínez J.C., Lobo R., Pérez Cisneros E.,Ochoa Tapia J.A. and De los Reyes J.A.Universidad Autónoma Metropolitana-Iztapalapa, Área de Ingeniería QuímicaAv. Rafael Atlixco 186, Iztapalapa, 09340 México, D.F.jarh@xanum.uam.mxIn order to reach current enviromental requirements regarding the content ofsulfur in diesel, it is essential to consider the existence of sulfur-containing moleculesof low reactivity (i.e. dialkildibenzothiophenes like 4,6-dimetildibenzothiophene,4,6-DMDBT) in the hydrodesulfurization (HDS) process. In these reactions, sulfurcontainingmolecules react with hydrogen in presence of a catalyst (usually a sulfidedCoMo or NiMo supported on alumina) at temperatures between 573-623 K andhydrogen pressure 5.1-101.0 MPa [1] in a trickle bed reactor. In recent time, reactivedistillation (RD) has been considered to be a highly promising process because itcombines the requirements of in situ separation with reaction and the temperatureand pressure are lower than those of the conventional processes. Some of us havereported interesting simulation results based on this technology [2]. For theseconditions it is needed to screen catalysts at the RD operation conditions in a threephases-system, analogous to a trickle bed reactor, where transport phenomena andhydrogen solubility have not been fully understood. Besides, experimental devicesmust consider low operating and construction costs along with low emissions. Thus,some authors reported results on HDS using trickle bed microreactors [3]. However,none of them have studied a range of operation conditions such as those required forRD. Moreover, the choice of appropriate solvent and model molecules are relevant toobtain information useful for industrial purposes.The aim of this paper was to carry out experimental work in a down-flow tricklebed microreactor under RD conditions. This reactor (diameter of 4 mm and a lengthof 30 mm) was packed with a commercial sulfided catalyst (NiMoP/Al 2 O 3 ) diluted withinert SiC for the HDS of 4,6-DMDBT. The influences of experimental conditions likelow pressure and temperature and a modification of solvent were evaluated in theinterphases mass transfer processes and the hydrogen solubility in the liquid phase.Previously, it was possible to define experimental conditions such as gas andliquid flow rates leading to small deviations to plug flow, trickle flow, high holdup andlow pressure drop. Fig. 1 shows experimental data for rate of reaction for HDS of4,6-DMDBT with decaline and dodecane as solvents.202