No abstract

Pyrolysis is one of the thermal cracking methods to convert hydrocarbon to liquid fuel. The quantity and quality of the process are dependent on several condition including temperature, reaction time, catalyst, and the type of reactor. Meanwhile, a gasoline fraction was maximum product to be considered in the pyrolisis process. Therefore, this study aims to increase the gasoline fraction in liquid fuel using stepwise pyrolysis with a long bed catalytic reactor downstream (LBCR). The LBCR downstream was equipped with the top and bottom outlet and the fed source was mixed municipal solid waste (MMSW). The activated natural dolomite at 500°C was used to allow the repetition of the secondary cracking. Also, the reactor temperature was setup at around 200°C-300°C and the pyrolizer was 400°C. To analyze the gasoline fraction and physical properties of liquid fuel, Gas Chromatography-Mass Spectroscopy (GC-MS) and ASTM standard were employed. The experimental results showed there was a significant increase in the gasoline fraction of liquid fuels compared to using direct catalytic cracking and absence of catalysts. By using a LBCR at 250°C, the liquid fuel obtained at top outlet (TO) and bottom outlet (BO) have 84.08 and 56.94 percent peak area of gasoline fraction (C5-C12), respectively. The average value (TO and BO) of the fraction at 250°C by LBCR was 70.51 percent peak area and it was increased by about 93.6% and 51.14% compared to without catalyst and direct catalytic, respectively. Furthermore, pyrolytic liquid oils were found to have kinematic viscosity of 2.979 and 0.789 cSt, density of 0.781 and 0.782 g/cm 3 , and flash point <−5°C for BO-250 and TO-250 liquid fuel, respectively. These results showed BO liquid fuel was comparable to diesel conventional fuel while TO liquid fuel was comparable to gasoline. Evidently, the presence of LBCR made a major contribution to generate multi secondary cracking and to produce more gasoline fraction from mixed MMSW feedstock, as well as to increase the physical properties of liquid fuel.