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

PP-V-9UPGRADING OF FCC-GASOLINES ON Pt,Pd/ZEOLITE CATALYSTSJenő Hancsók*, Szabolcs Magyar*, Dénes Kalló***University of Pannonia, Dep. Hydrocarbon & Coal Proc., H-8201 Veszprém,P.O Box: 158, Hungary, Phone: +36 88/624413, Fax: +36 88/624520,E-mail: hancsokj@almos.uni-pannon.hu**Chemical Research Centre, Institute of Chemistry, Hungarian Academy of Sciences,Budapest, P.O. Box 17, H-1525, Hungary,Phone: +36 1/4381100, E-mail: kallo@chemres.huIn the last years sulphur content of engine gasolines was stepwise reduced to 50(10)mg/kg in the European Union [1]. This is mainly caused by environmental protection reasons(acid rains, preserve exhaust gas after treatment systems from sulphur compounds). Sulphuroxides, sulphurous acid and sulphuric acid can cause the corrosion of the exhaust gas system,furthermore, by entering into engine oils these compounds can decrease the basic reserve ofthe engine oils [2]. Nitrogen content of engine gasolines was not limited yet, however duringthe combustion they form nitrogen oxides, thus they definitely increase the NOX emission ofvehicles [3].By the use of neither the conventional, nor the new generation catalysts - developed forthe sulphur reduction of FCC gasolines - reduction of both sulphur and nitrogen content ofFCC gasolines is not possible with low octane loss (≤ 3 units) [4,5].Based on the foregoing the objective of our research work was to find a catalyst which issuitable to produce low sulphur containing (≤ 10 mgS/kg) and practically nitrogen-free(≤1 mgN/kg) FCC gasoline with low octane loss (≤ 3 units). The experiments were carried outin reactor system consisting of a down-flow fixed bed tubular reactor working without backmixing.During the investigation of several catalysts having different composition we foundthat the expediently selected Pt,Pd/zeolite catalysts are suitable for aims.Under expediently selected process conditions (T = 265-280°C; ptotal = 30 bar:LHSV=1.2-2.0; H 2 /hydrocarbons ratio: 300 Nm 3 /m 3 ), the investigated PtPd/USY catalyst isable to produce nitrogen free FCC gasolines of ca. 10 mg/kg sulphur content from FCCgasoline feedstocks containing 50-150 mg/kg sulphur, 10-25% olefins and less than 50 mg/kgnitrogen with a lower loss of octane number (2-2.5 units) compared to those produced overconventional (4.5-5.5 units) and new (3-3.5 units) CoMo/alumina catalyst. This is a newpossible application field of PtPd/USY catalyst. Use of this product is advantageous forreduction of nitrogen-oxides emitted by gasoline-fuelled passenger cars.473