Effect of the catalyst in the BTX production by hydrocracking of light cycle oil

AbstractCatalysts to produce the important petrochemicals like benzene, toluene, and xylene (BTX) from refinery feedstocks, like light cycle oil (LCO) are reviewed here by covering published papers using model mixtures and real feeds. Model compounds experiments like tetralin and naphthalene derivatives provided a 53–55% total BTX yield. Higher yields were never attained due to the inevitable gas formation and other C9+-alkylbenzenes formed. For tetralin, the best catalysts are those conformed by Ni, CoMo, NiMo, or NiSn over zeolite H-Beta. For naphthalene derivatives, the best catalysts were those conformed by W and NiW over zeolite H-Beta silylated. Real feeds produced a total BTX yield of up to 35% at the best experimental conditions. Higher yields were never reached due to the presence of other types of hydrocarbons in the feed which can compete for the catalytic sites. The best catalysts were those conformed by Mo, CoMo, or NiMo over zeolite H-Beta. Some improvements were obtained by adding ZSM-5 to the support or in mixtures with other catalysts.

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

Applied Petrochemical Research ◽

10.1007/s13203-021-00276-w ◽

2021 ◽

Author(s):

Georgina C. Laredo ◽

Ricardo Águeda-Rangel ◽

Alfonso García-López ◽

José Luis García-Gutiérrez ◽

Eli Hazel Olmos-Cerda

Keyword(s):

Chemical Composition ◽

Aromatic Compounds ◽

Light Cycle ◽

Light Hydrocarbons ◽

Experimental Conditions ◽

Light Cycle Oil ◽

Flame Ionization ◽

Different Types ◽

Benzene Toluene ◽

Cycle Oil

AbstractThe effect of the chemical composition of the hydrotreated light cycle oil (HDT LCO) on the benzene, toluene, ethylbenzene, and xylene (BTEX) production by a hydrocracking (HCK) procedure, is presented. Six different types of HDT LCOs were obtained by submitting two types of LCOs to hydrotreating (HDT) with different catalysts and experimental conditions. The products were analyzed as mono-, di- and tri-aromatic compounds using the supercritical fluid chromatography (SFC) method (ASTM D5186). The HDT LCOs were subjected to HCK with a 50/50 in weight mixture of nickel-molybdenum on alumina (NiMo/Al2O3) and H-ZSM5 (NiMo/H-ZSM5, 50/50) at 375 °C, 7.5 MPa, 1.2 h−1, and 750 m3/m3 H2/Oil. The HCK products were analyzed by gas chromatography with a flame ionization detector (GC-FID) and divided into five groups: gas, light hydrocarbons (LHCs), BTEX, middle hydrocarbons (MHCs), and heavy hydrocarbons (HHCs).The results showed that the BTEX formation ranged from 27.0 to 29.8 wt.% and it did not show a significant dependence on the mono-aromatic (59.9 and 75.6 wt.%), total aromatic (61.1–84.2 wt.%) contents or MHCs conversion (58.3–64.3 wt.%) from the departing HDT LCO feedstock. This result implies that, contrary to previous expectations, the BTEX formation does not directly depend on the amounts of total or mono-aromatic compounds when departing from real feedstocks. A GC-PIONA (paraffin, isoparaffin, olefin, naphthene, aromatic) characterization method (ASTM D6623) for mechanism understanding purpose was also carried out.

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Effect of the catalytic system and operating conditions on BTX formation using tetralin as a model molecule

Applied Petrochemical Research ◽

10.1007/s13203-019-00237-4 ◽

2019 ◽

Vol 9 (3-4) ◽

pp. 185-198 ◽

Cited By ~ 2

Author(s):

Georgina C. Laredo ◽

Patricia Pérez-Romo ◽

Pedro M. Vega-Merino ◽

Elva Arzate-Barbosa ◽

Alfonso García-López ◽

...

Keyword(s):

Volume Ratio ◽

Acid Sites ◽

Operating Conditions ◽

Light Cycle ◽

Light Cycle Oil ◽

Model Molecule ◽

Benzene Toluene ◽

Molybdenum Catalysts ◽

Mechanical Mixtures ◽

Cycle Oil

Abstract Light cycle oil (LCO) is an inexpensive feedstock for the production of high-added-commercial-value-mono-aromatic compounds such as benzene, toluene and xylenes (BTX). To extend the knowledge on the processing of LCO for BTX production, the hydrocracking reaction was studied using a commercial NiMo/Al2O3 catalyst, ZSM-5 zeolite and their mechanical mixtures (20/80, 30/70 and 50/50) for processing tetralin as model feedstock in a bench-scale-trickle-bed reactor at 450–500 °C, 3.9–5.9 MPa, 1.3 1/h and H2/feed volume ratio of 168–267 m3/m3. Accessible, well-dispersed and strong Brönsted acid sites eased the hydrocracking of tetralin to BTX and the metallic hydrogenation functions from nickel–molybdenum catalysts were also required to minimize deactivation. To achieve suitable tetralin conversions (86–95 wt%), high BTX selectivity in the liquid phase (44–70 wt%) and suitable catalytic activities for coke precursor hydrogenation (to reduce deactivation), NiMo/Al2O3//ZSM-5 mixtures (50–80 ZSM-5) were employed, which probed to be effective.

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Model Compounds for Light Cycle Oil Conversion

Industrial & Engineering Chemistry Research ◽

10.1021/ie00038a037 ◽

1995 ◽

Vol 34 (11) ◽

pp. 3970-3973 ◽

Cited By ~ 12

Author(s):

L. Deane Rollmann ◽

Paul A. Howley ◽

Dominick N. Mazzone ◽

Hye Kyung C. Timken

Keyword(s):

Light Cycle ◽

Model Compounds ◽

Light Cycle Oil ◽

Cycle Oil

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Effect of the experimental conditions on BTX formation from hydrotreated light cycle oil

Applied Petrochemical Research ◽

10.1007/s13203-020-00242-y ◽

2020 ◽

Vol 10 (1) ◽

pp. 21-34

Author(s):

Georgina C. Laredo ◽

Patricia Pérez-Romo ◽

Ricardo Agueda-Rangel ◽

Alfonso García-López

Keyword(s):

Light Cycle ◽

Experimental Conditions ◽

Light Cycle Oil ◽

Cycle Oil

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Roles of Nanostructured Bimetallic Supported on Alumina-Zeolite (AZ) in Light Cycle Oil (LCO) Upgrading

Catalysts ◽

10.3390/catal11111277 ◽

2021 ◽

Vol 11 (11) ◽

pp. 1277

Author(s):

Jianglong Pu ◽

Haiping Zhang ◽

Min Wang ◽

Kyle Rogers ◽

Hongmei Wang ◽

...

Keyword(s):

Catalyst Support ◽

Cetane Number ◽

Acid Sites ◽

Light Cycle ◽

Model Compounds ◽

Light Cycle Oil ◽

Higher Temperature ◽

Cycle Oil ◽

Lower Temperature ◽

Nitrogen Contents

Light cycle oil (LCO) is one of the major products in Fluid catalytic cracking (FCC) processes, and has drawbacks such as high aromatics, sulfur, and nitrogen contents, and low cetane number (CN). Hydro-upgrading is one of the most typical processes for LCO upgrading, and alumina-zeolite (AZ) is an effective hydrotreating catalyst support. This paper examined the effects of different bimetallic catalysts (CoMo/AZ, NiMo/AZ, and NiW/AZ) supported by AZ on hydro-upgrading of both model compounds and real LCO. CoMo/AZ preferred the direct desulfurization (DDS) route while the NiMo/AZ and NiW/AZ catalysts favored the desulfurization route through hydrogenation (HYD). The presence of nitrogen compounds in the feed introduced a competitive adsorption mechanism and reduced the number of available acid sites. Aromatics were partially hydrogenated into methyltetralines at first, and then further hydrogenated, cracked, and isomerized into methyldecalins, monocyclic, and methyltetralines isomers. CoMo/AZ is the best hydrodesulfurization (HDS) catalyst for the model compounds at low H2 pressure (550 psi) and for LCO at lower temperature (573 K), while NiMo/AZ performs the best for LCO at higher temperature (648 K). NiMo/AZ is the best hydrodenitrogenation (HDN) catalyst for LCO. The hydrodearomatization (HDA) performances of NiMo/AZ and NiW/AZ improved significantly and overwhelmingly higher than that of the CoMo/AZ when the H2 pressure was increased to 1100 psi.

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Light Cycle Oil Upgrading to Benzene, Toluene, and Xylenes by Hydrocracking: Studies Using Model Mixtures

Industrial & Engineering Chemistry Research ◽

10.1021/acs.iecr.7b02827 ◽

2017 ◽

Vol 56 (39) ◽

pp. 10939-10948 ◽

Cited By ~ 21

Author(s):

Georgina C. Laredo ◽

Patricia Pérez-Romo ◽

José Escobar ◽

José Luis Garcia-Gutierrez ◽

Pedro M. Vega-Merino

Keyword(s):

Light Cycle ◽

Light Cycle Oil ◽

Benzene Toluene ◽

Cycle Oil

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Selective hydrogenation of light cycle oil for BTX and gasoline production purposes

International Journal of Chemical Reactor Engineering ◽

10.1515/ijcre-2020-0144 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Eli H. Olmos-Cerda ◽

Georgina C. Laredo ◽

Patricia Pérez-Romo ◽

Ricardo Águeda-Rangel ◽

Alfonso García-López

Keyword(s):

Aromatic Hydrocarbons ◽

Space Velocity ◽

Reaction Rates ◽

Light Cycle ◽

Pseudo First Order Reaction ◽

Experimental Conditions ◽

Light Cycle Oil ◽

Liquid Hourly Space Velocity ◽

Sulfur And Nitrogen Compounds ◽

Cycle Oil

Abstract The study of the best experimental conditions and catalyst for the hydrogenation (HYD) of light cycle oil (LCO) for upgrading purposes was carried out. The objective was to examine the ability of two commercial hydrotreatment (HDT) catalysts for selective aromatic saturation. The effect of the hydrotreatment operation parameters (temperature, pressure, liquid hourly space velocity, H2/HC ratio) on the sulfur and nitrogen contents and in the saturation of aromatic hydrocarbons was also investigated. The goal was to obtain the highest conversion to mono-aromatic hydrocarbons from this di-aromatic (naphthalene derivatives) type feedstock, and at the same time to get reasonable hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) performance to avoid contaminant hydrocarbons for the next step (usually hydrocracking, HCK). An appropriate hydrotreated product with the highest concentration of mono-aromatic derivatives, a minimum reduction on the total aromatic content, and suitable decrements of sulfur and nitrogen compounds, was achieved using a cobalt-molybdenum supported on alumina catalyst, at 330 °C, 5.5 MPa, and a liquid hourly space velocity of 1.1 h−1. Additionally, the kinetics of the HDA was studied, assuming a lump characterization into tri-, di- and mono-aromatic and aliphatic hydrocarbons, pseudo-first-order reaction rates between these conversions, and thermal losses and diffusional resistances to be undetectable.

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