The Conversion of Light Naphtha Into Aromatics by Using Promoted Zeolite Catalysts

Abstract

Zeolites of the ZSM-5 family are poor for converting liquid paraffins into aromatics, but commercially available H-ZSM-5 can be effectively promoted with zinc or gallium. A gallium-promoted zeolite was used for the conversion of pentane and a natural-gas condensate into aromatic-rich liquid products. Optimum performance was obtained at temperatures of 475ºC and weight-hourly space velocity of 1 h^-1. The aromatic products were principally benzene, toluene and xylene, with the benzene content increasing with increasing conversion temperature. Operation of the catalyst at high severity (high temperature, low space velocity) produced a liquid product containing over 90% of aromatics. Lower severity produced less aromatics but higher overall liquid yield.