Conversion of Butane-Butylene Mixtures over B(Al)-HZSM-5 Catalyst Prepared by Impregnation Technique

3 S.C."Oltplast" S.A., Onesti, Romania This paper presents the results of the conversion of light hydrocarbons (mixtures of butanes/butylenes with variable composition) resulted as by-products of the petroleum refining (FCC) over bifunctional B(Al)-HZSM- 5 catalyst prepared by impregnation of HZSM-5 zeolite with boric acid. The catalyst was characterized using XRD, SEM, EDX and NH 3 -TPD for their structure, morphology and acidity. The catalytic activity of the same catalyst was examined during 17 catalytic tests (with regeneration of catalyst after each test) using mixtures of butanes-butylenes. The catalytic tests were carried out in a continuous fixed bed flow stainless-steel reactor (Twin Reactor System Naky) fed at a WHSV = 1 h -1 at a temperature of 450 o C and a pressure of 8 atm (tests no. 1-11) and 4 atm (tests no. 12-17), respectively. Catalytic activity and selectivity towards liquid products - BTX aromatic hydrocarbons and "oligo" (iC 5 -iC 10 , nC 5 -nC 10 , >C 10 ) - depend on time on stream, composition of butanes-butylenes mixture and pressure. In the first hours of each test the aromatic BTX are the main component of the liquid product (connected with butylenes consume) and after that, the "oligo" fraction become predominant. The yield of liquid product, density and Motor Octanic Number alter between 18.60 wt% - 37.9 wt%, 0.760 - 0.852 g/cm 3 and 97 - 109, respectively. The yield of liquid product (>30 wt %) and MON higher than 100 was obtained working at 4 atm pressure.