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

PP-III-12IMPROVING THE PROCESS OF HIGHER PARAFFINDEHYDROGENATION ON THE BASIS OF NONSTATIONARYKINETIC MODELKravtsov А.V., Ivanchina E.D., Ivashkina Е.N., Yuriev Е.М.Tomsk Polytechnic University, 634050, Lenina Street, 30, Tomsk, Russia,fax: +7 (3822) 563435, e-mail: ivashkinaen@rambler.ruThe potential demand of domestic market of synthetic detergents in a raw material base,which is linear alkyl benzenes (LAB) and linear alkyl benzene sulphanates (LABS), is about100 thous. tons per year. One of the possible ways of the set productivity improvement isinclusion of the second dehydrogenation reactor in parallel operation.At present, only one dehydrogenation reactor is included into set operation, while thesecond reactor being a reserve one. Technical staff supposes that the reserve reactor inclusioninto parallel operation allows increasing the volume of released production withoutfundamental reconstruction of operative equipment.Forecasting operation of such variant of scheme of the operative set may be performedthe most efficiently applying the kinetic model developed by the authors, describingsufficiently the industrial process of higher paraffins dehydrogenation, and technologicalmodeling system created on its basis (TMS) [1].Mathematical description of dehydrogenation process is taken as a principle of thetechnological modeling system, which contains the following issues: current and prognosticcalculation of higher paraffins dehydrogenation processes and by-products hydrogenation,material balance calculation of the set in whole, visualization of the obtained results (curves,tables).Using the developed TMS the prognostic calculations set indexes operation were carriedout at the following invariable initial data: molar ratio Н 2 /hydrocarbons = 7:1; n-paraffinsvolume flow for both reactors 75 m 3 /h; LAB generation – 180 t./day.At parallel operation of dehydrogenation reactors the main factor, defining the change ofefficiency indexes of this process, is raw materials load reduction per one reactor, andtherefore, decrease of volumetric feed rate, i.e. increase of contact time of agents and catalyst.Reduction of volumetric raw materials feed rate allows decreasing temperature profile of theprocess, on the one hand, and as a result, increasing catalyst service life (Fig. 1).On the other hand, it does not allow increasing LAB capacity (this index remains almostat the same level or it will be a little bit higher due to a longer contact time).325