Boreskov Institute of Catalysis of the Siberian Branch of Russian ...

PP-III-41MODELLING AND DESIGN OF THE REACTORS FOR THE PROCESSOF THERMOCATALYTIC HYDROGENATION OF LIQUIDPRODUCTS OF PYROLYSIS FOR OBTAINING BENZENEA.I. Babaev, A.M. Aliyev, A.Z. TahirovAzerbaijan National Academy of Sciences, Institute of Chemical Problems,e-mail: ITPCHT@itpcht.ab.azAt present, sources of raw material for obtaining of benzene are the aromatichydrocarbons C 7 -C 9 and hydrorefined fraction of pyrocondensate, benzene-tolnenexylene(BTX).Hydrodealkylation and hydrocracking of non-aromatic hydrocarbons of BTXfraction is carried out by thermal and catalytic methods under pressure of hydrogen, 2.5-6.3 MPa and at high temperature, 620-730°C. Shortages of the thermal process are greaterformation of polycyclic aromatic hydrocarbons, lesser yield of ethane and propane and hightemperature. Shortages of the catalytic process are high pressure, complication of regulationof temperature and large expenditure of the catalyst.In our Institute it has been developed the thermocatalytic process which combines theadvantages of thermal and catalytic processes [1]. Thermocatalytic version of the processforesees the realization of hydrogenation of BTX fraction in two consecutive adiabaticreactors. In the first reactor with injection mixing, the degree of hydrocracking achieves 90%.In the second reactor with the polyfunctional catalyst – B-17/3, the reaction of hydrocrackingof non-aromatic hydrocarbons finishes completely. At the description of mechanism of theprocess we have considered the aromatic hydrocarbons, С 8 ; naphthene hydrocarbons, C 6 -C 8 ;paraffin hydrocarbons, C 6 -C 8 and hydrocarbons, C 1 -C 4 in the aggregated form. Taking intoaccount that hydrodynamics of the injection reactor corresponds to model of ideal stirred, thekinetic model of the thermal reactor may be written as:P = P1PP = PPPP23456= P= P= P= PT = T0102030405060+ V+ V+ V+ V+ V+ V⎛+ V ⎜−⎝( R2− R1)/v( R1− 2R5− R6)( − R2)/v( R6− R3)/v( R3− R4)/v( R )/v56∑i=1/ v⎞Ri ΔHi/ CpρRT−αX/⎠( T − T ) ⎟ vwhere R i is a rate of reaction i; ∆H i is a heat of reaction i; C P is an average heat capacity ofthe reaction environment; ρ is a density of the reaction environment; V is a volume of the382(1)