Catalytic Cracking of Heavy Aromatics and Polycyclic Aromatic Hydrocarbons over Fluidized Catalytic Cracking Catalysts

Abstract

The distribution of products in the range of gasoline and middle distillates cuts obtained in the catalytic cracking of heavy aromatics and polycyclic aromatic hydrocarbons over a FCC catalyst was studied. 1-Phenyloctane, biphenyl, fluorene, 9,10-dihydrophenanthrene, naphthalene, phenanthrene, pyrene and benz [a]anthracene were used as model compounds of alkylaromatic, naphthenic-aromatic and polyaromatic hydrocarbons which are present in VGO and residual feedstocks in the FCC process. The catalyst was used in its fresh and equilibrium forms at 450 ºC in a CREC Riser Simulator reactor with reaction times from 2 to 6 s. Thermal cracking reactions overwhelm the catalytic conversion of naphthenic-aromatic compounds such as fluorene and 9,10-dihydrophenanthrene. Under the same conditions, the fresh catalyst was more active than the equilibrium catalyst. The alkylaromatic, naphthenicaromatic and polyaromatic hydrocarbons, showed catalytic conversions which increased, CORRESPONDING AUTOR *were relatively stable and decreased, respectively, as a function of reaction time. The distribution of products suggested that most important reactions were thermal dehydrogenation, hydrogen transfer, ring opening, cracking and condensation. It was shown that all the model compounds are cracked, yielding particularly benzene in the gasoline range and coke.

Abatement efficiency and fate of EPA-Listed PAHs in aqueous medium under simulated solar and UV-C irradiations, and combined process with TiO2 and H2O2

“…In the Figure 3.b we are witness of increased peak of target compounds between sampling times of 1 min and 2 min in UV-C/TiO2 test and then decrease the DE peaks in following sampling times, could be explained by catalytic cracking of PAHs via HMW-PAHs to LMW-PAHs during the process (Pujro et al, 2015) HMW-PAHs include compounds with five and six fused aromatic rings which are strongly carcinogenic and mutagenic. Further, due to the number of benzene rings and unsaturation degree they become increasingly stable and nonbiodegradable (Stogiannidis and Laane, 2015).…”

“…According to the results, high performance of UV-C/H2O2, Xe, and Xe /H2O2 treatments was evidenced in degradation of Acy. The Acy decreased 6.94% at min 5 subsequently 100% after min 2 under Xe/TiO2 treatment, it could be explainable as catalytic cracking of PAHs by high molecular weight (HMW-PAHs) to lower molecular weight (LMW-PAHs) PAHs during the process too (Pujro et al, 2015).…”

“…The results suggest the high performance of Xe and Xe/H2O2 treatments in degradation of Nap. Observation of the increased peak of Nap at primary sampling times (1 and 2 min) of the Xe/TiO2 treatment and stay undegraded (just 40% degraded) up to end of treatment (Figure 4.b) could be explained as catalytic cracking of PAHs by high molecular weight (HMW-PAHs) to lower molecular weight (LMW-PAHs) PAHs during the process (Pujro et al, 2015).…”

Potentials of African Star Apple (<i>Chrysophyllum albidum)</i> Fruit Shell Adsorbent in Recovery of Valuable Hydrocarbons for Spent Engine Oil

“…The possible reactions during lubricant usage in the crankcase were thermal dehydrogenation, ring opening, epoxidation, cracking, and condensation of aromatics such as, phenyloctane, biphenyl, fluorene, 9,10-dihydrophenanthrene, naphthalene, phenanthrene, pyrene, and benzo(a)anthracene which are base oil components or additives in the lubricant formulation [39].…”

Selective C−C Hydrogenolysis of Alkylbenzenes to Methylbenzenes with Suppression of Ring Hydrogenation

“…Conversions of heavy hydrocarbon resources into value‐added chemicals are becoming more and more important, since heavier crude oil with high mining cost has been more supplied . Monoaromatic hydrocarbons with a long side chain are included in products of catalytic cracking of polycyclic aromatic hydrocarbons which are one class of main components of heavy oil . Except ethylbenzene, monoaromatic hydrocarbons with long alkyl chains are not so useful chemicals and are mainly used as fuel.…”