Synergistic Process for FCC Light Cycle Oil Efficient Conversion To Produce High-Octane Number Gasoline

Abstract

Light cycle oil (LCO) from fluid catalytic cracking (FCC) was treated by selective hydrogenation and then cracked in a FCC apparatus. Compared with LCO, hydrogenated LCO (hydro-LCO) exhibited remarkable FCC performance, recording with that 50.83 wt % hydro-LCO was converted into gasoline fraction. This is attributed to the reduction of aromatics in hydro-LCO, especially for the multiring aromatics. After hydrogenation, the amount of multiring aromatics significantly decreased from 63.2 to 9.5 wt %, while naphthenoaromatics (including indans, tetralin, and indenes) increased from 8.8 to 34.2 wt %. In accordance with the experimental results and theoretical analysis of LCO reaction characteristics, a synergistic process for LCO efficient conversion to high octane number gasoline was proposed, and simulation experiments were carried out. The results show that, compared with routine FCC, 20 wt % higher conversion and 16 wt % more gasoline could be obtained. Moreover, gasoline from synergistic process exhibited decreased sulfur and olefins, but increased aromatics, and thereby improved octane number. These findings indicate that the proposed synergistic process could be an effective option for producing gasoline with high octane number.

Technical review on flexible processing middle distillate for achieving maximum profit in China

“…Given that the activation energy of hydrogen transfer (94 * 125 kJ/mol) is lower than that of subsequent cracking (184 * 205 kJ/mol) [29,36], hydrogen transfer is preferred in FCC system. To suppress hydrogen transfer, high temperature is recommended since hydrogen transfer is exothermic while catalytic cracking is endothermic.…”

“…In terms of LTAG technology, it not only can use current hydrogenation unit with appropriate pressure, e.g., gas oil hydro-processing unit [37], and diesel hydro-upgrading unit with minimum investment, but also can utilize FCC with two-stage risers. Gao et al recently reported that the decrease by 19.68% of diesel was converted to 16.38 wt% gasoline and 2.63 wt% LPG [36].…”

Effect of the chemical composition of six hydrotreated light cycle oils for benzene, toluene, ethylbenzene, and xylene production by a hydrocracking process

“…In the case of LCO 2, only the HDT-1 catalyst (CoMo/Al 2 O 3 ) was used, and the sulfur content went from 4.3 wt.% (43,000 mg/kg) to 300 and 130 mg/kg when the used temperatures were 320 and 330 °C and the nitrogen contents ranged from 196 to 1.3 and 0.3 mg/kg (Table 4). Since generally, the catalysts employed in HCK processes are sulfides of group VI and VIII metals, remaining sulfur can be useful for keeping the catalyst active, however, the presence of nitrogen compounds is known to be harmful to the HCK catalyst [22,23]. Therefore, about 200 mg/kg of sulfur must remain in the HDT LCO to maintain the catalyst activity for the next HCK process.…”

Understanding the Nanoconfinement Effect on the Ethanol-to-Propene Mechanism Catalyzed by Acidic ZSM-5 and FAU Zeolites

“…Propene is an essential raw material for the production of propene derivatives such as polypropylene, acrylic acid, and acrylonitrile in the petrochemical industry. − Nowadays, propene is mainly produced as a byproduct of naphtha steam cracking and fluid catalytic cracking (FCC). − With the increasing demand for propene derivatives, traditional methods such as FCC, olefin disproportionation, and propane dehydrogenation have limited the capacity of production of propene because of their high operating temperature and economic cost. Although the methanol-to-propene (MTP) technique avoids the drawbacks above, the relatively high price of methanol slows down its applications in a short time. − In recent years, ethanol to propene (ETP) has attracted extensive attention with the progress of biological fermentation technology.…”