Gasoline Yield Enhancement in Fluid Catalytic Cracking by Coprocessing of Petroleum Gasoil with Refined Bleached Deodorized Palm Oil and Palm Fatty Acid Distillate

Abstract

Gasoline is liquid hydrocarbon fuel used for spark-ignition engine. Most of gasoline production is carried out in the petroleum oil refinery through several stages of process and fluid catalytic cracking (FCC) is an important process that can convert some of heavy oil fractions like vacuum gasoil (VGO) and residue to be cracked into gasoline and lighter products. Consumption of gasoline for transportation fuel in Indonesia is higher than its production capability, so this gap has compelled to search the alternative process route using renewable feedstock. Coprocessing of petroleum gasoil with crude palm oil in fluid catalytic cracking had been investigated previously resulting in lower value of conversion as well as gasoline yield when applying co-feeds at higher level of vegetable oils. Cracking feedstock containing triglyceride and fatty acid from vegetable oil is supposed to be the other possibility as a reason of conversion and yield changes. The research work is aimed to find out another way for gasoline yield upgrading in fluid catalytic cracking process using available catalyst by coprocessing of VGO with refined bleached deodorized palm oil (RBDPO) and small amount of palm fatty acid distillate (PFAD). The experimental work of cracking reaction was performed on fluid-bed reactor of ACE unit at temperature of 530 °C, nearly atmospheric pressure and catalyst-oil ratio of 5.5 g/g. Three kind of oil feeds were tested namely VGO, VGO mixed with 5% RBDPO and VGO added with 5% RBDPO-PFAD of mixing ratio 9:1. The cracking reaction results in gaseous and liquid products. The gaseous phase product was analyzed using online gas chromatography to detect light hydrocarbon components of C1, C2 and H2 as dry gas and hydrocarbon components of C3 and C4 as LPG. The liquid item was investigated through gas chromatography of simulated distillation to separate fluid components including gasoline, light cycle oil (LCO) and slurry oil. Carbon material placed on catalyst through cracking reaction was analyzed at regeneration step of spent catalyst passed through catalytic converter by online Infrared method. Coprocessing of VGO with 5% RBDPO and VGO with 5% RBDPO-PFAD can alter conversion and product yields. The presence of triglyceride and fatty acid in oil feeds during cracking reaction influence signifi- cantly to gasoline enhancement. Although this coprocessing work has shown initial phenomenon in accordance with hypothesis, further investigation is necessary to explore deeper in order to obtain an optimized process condition by various levels of coprocessing feed.