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

PP-III-7ALKYLATION REACTOR MODELING IN LINEARALKYLBENZENES PRODUCTIONVeronica A. Fetisova, Edward V. Malahov, Elena N. IvashkinaTomsk Polytechnic University, Lenin Street, 30, 634050, Tomsk, Russia;fax: +7(3822)563-435; e-mail: v1205f@list.ruAlkylation of benzene with long-chained olefines is a part of LAS (linear alkylbenzenesulfonates) production, which are known as widespread surfactants. Biodegradability anddetergent properties of these surfactants strongly depends on production conditions and rawmaterials composition. Since serious interference in functioning of a real industrial unit inorder to investigate influence of different factors is an inexpedient, computer simulation of thereactor process is an efficient instrument in improving existent technology.The developed mathematical model is based on experimental data of hydrofluoricalkylation process at Kirishi industrial LAB-production unit and contains description ofkinetic and hydrodynamic aspects of this process.Kinetic model of this process is built upon the following kinetic scheme:CH + CH ⎯⎯→ CH(CH 1) (linear alkylbenzene (LAB) formation)k1n 2n 6 6 6 5 n 2n+i− C H + C H ⎯⎯→i− C H ( C H 1) (non-linear alkylbenzene (NAB) formation)k 2n 2n 6 6 6 5 n 2n+CH( CH+) + C H ⎯⎯→ CH( CH )( C H )formation)k 36 5 n 2n 1 m 2m 6 4 n 2n+ 1 m 2m+14)2 6 4( 2 1)( 2 1) kk k n n+ m m+ 6 3( n 2n+ 1)( m 2m+1)(k 2k+1 k 5CH + 2CH ⎯⎯→ CH ( CH)(diphenylalkane (DPA) formation)(dialkylbenzene (DAB)CH + CH CH C H ⎯⎯→ CH CH C H CH (polyalkylbenzene (PAB) formation)n 2n− 2 6 6 n 2n6 5 2Where n, m, k – carbon numbers; linear alkylbenzenes – desired products with highbiodegrability; non-linear alkylbenzenes – by-products with low biodegrability,dialkylbenzenes, polyalkylbenzenes, diphenylalkanes – by-products, which are oftenaggregated under name «heavy alkylate».Plug-flow model was proposed to describe the hydrodynamic conditions in the reactorbecause of its geometrical characteristics. This assumption was checked by calculation ofPekle’s number, which is equal 576. So, diffusion flows in the reactor can be neglected.Taking into account kinetic and hydrodynamic parts, the mathematical model of thealkylation process reactor has the following form:315