Efficient processing of crude oil using direct cracking at high temperatures over modified FCC catalysts

The direct cracking of Bach Ho crude oil, having API gravity of 41 degrees, over equilibrium FCC catalyst (Ecat), modified FCC catalyst (HT-FCC) and ZSM-5 additive were studied at 620-650 degrees C using short-contact-time micro activity testing unit. HT-FCC catalyst was prepared by the treatment of Ecat with oxalic acid in reflux condition. This treatment largely improves the porosity while keeping the particle size of Ecat. Hence, it leads to an important enhancement in catalytic cracking activity. Due to high activity of HT-FCC catalyst, the direct cracking of crude oil can be performed at a low catalyst-to-oil ratio (C/O) which helps to decrease the yield of dry gas. At 620-650 degrees C, C/O of 1.5-2.5, 18-23 wt.% of light olefins, 3-6 wt.% of dry gas together with 51-59 wt.% of gasoline yields can be obtained with HT-FCC catalyst. ZSM-5 addition favors the conversion of gasoline to light olefins. Compared to the results reported in literature, the use of HT-FCC and ZSM-5 catalysts at 650 degrees C, low C/O of 1.5 shows promising performances: (i) much lower dry gas yield (8%), (ii) high light-olefins yield (32%) while maintaining high gasoline yield (43%), and (iii) high BTXs content in gasoline (45%).