OP-II-3

PP-II-57The reactant concentration in the reactor feed is periodically varied in the form ofa square wave function. In the first part of a period, the concentration corresponds tothe hydrogen + benzene mixture and then, the flow was replaced by a flow ofhydrogen + thiophene (or hydrogen + benzene + thiophene) in the second part of aperiod. The split between the two parts of a period is defined by the parameter γ. Forγ = 0, the reactor is operated under steady-state with a constant feed concentration.The modeling was performed with the use of the mathematical model of thecontinuous stirred tank reactor. For modeling was used the unsteady state kineticmodel, which describes well the dynamics of changes in the benzene conversion withpresence and absence thiophene [5]. Kinetic of both benzene hydrogenation andthiophene hydrogenolysis on sulfide Ni-Mo/γ-Al 2 O 3 catalyst includes 7 steps. Themodel has been developed assuming that the catalyst surface contains only one typeof active sites - nickel atoms found in the sulfide bimetallic complex - on which thereactions of hydrogenolysis of bond C-S and benzene hydrogenation occur.On the base of the kinetic model, the theoretical analysis of the reactorperformance under unsteady state conditionswas carried out. The unsteady stateconditions on the catalyst surface are supposed to be created by forced oscillationsof concentration of thiophene in the reactor inlet. The influence of various parameterslike cycle split, length of forced oscillations period in the reactor was investigated withrespect to the conversion of the benzene. The optimal cycle split is 0.1, the length offorced oscillations period in the reactor consists of 300 min. It is shown that underperiodic reactor operation an average benzene conversion can be up to severaltimes higher than the steady state value.References[1]. B.H. Cooper, B.B.L. Donnis: Appl. Catal. A: General, 1996, 137, 203.[2]. C. Song, X. Ma. Applied Catalysis B: 2003, 41, 207.[3]. P.L. Silveston, R.R. Hudgins, A. Renken, Catal. Today. 1995, 25, 91.[4]. S.I. Reshetnikov, E.A. Ivanov, L. Kiwi-Minsker, A. Renken, Chem. Eng. Technol. 2003, 26, 751.[5]. E.A. Ivanov, S.I. Reshetnikov, M.V. Sydyakin and A.N. Startsev. React. Kinet. Catal. Lett. 2006,88, 399.AcknowledgementsThe authors acknowledge to RFBR (Grant № 09-03-90406-Ukr_f_а) and FRSF (Grant№ F28/267-2009) for the financial support.438