Catalytic Aromatization of Naphtha using Different Catalysts

Abstract

Heavy Iraqi petroleum naphtha with average boiling point of 385K and 0.7388 specific gravity was tested with various types of prepared and commercial catalysts for the aim of production toluene and xylenes. The aromatization process carried out with prepared chromia-alumina catalyst promoted by potassium and cerium, and with commercial platinum-alumina catalysts promoted by rhenium and tin , in affixed bed reactor . The aromatization process carried out a range of temperatures varied from 703 to 763K, liquid hourly space velocity varied from 0.2 to 0.5h-1,and atmospheric pressure. The general behavior of aromatization process indicates that toluene and xylenes were increased with increasing temperature of reaction, while decreased with increasing LHSV. Prepared chromia-alumina promoted with potassium and cerium catalyst gives conversion of n-heptane and n-octane to toluene (31% yield ) and to xylenes (80% yield) respectively, while chromia-alumina promoted only with potassium gives maximum conversion of n-heptane and n-octane to toluene (15% yield ) and to xylenes (50% yield ) respectively. Commercial platinum-alumina catalysts promoted with tin gives maximum conversion of n-heptane and n-octane to toluene (42% yield ) and to xylenes ( 63% yield) respectively. Any way , commercial platinum- alumina promoted with rhenium and the unpromoted catalysts gives very low conversions. Keywords: Catalytic reforming, Aromatization of naphtha, BTX production.