Light Cycle Oil Research Articles

A Hybrid FCC/HZSM-5 Catalyst for the Catalytic Cracking of a VGO/Bio-Oil Blend in FCC Conditions

The performance of a commercial FCC catalyst (designated as CY) and a physically mixed hybrid catalyst (80 wt.% CY and 20 wt.% HZSM-5-based catalyst, designated as CH) have been compared in the catalytic cracking of a vacuum gasoil (VGO)/bio-oil blend (80/20 wt.%) in a simulated riser reactor (C/O, 6gcatgfeed−1; t, 6 s). The effect of cracking temperature has been studied on product distribution (carbon products, water, and coke) and product lumps: CO+CO2, dry gas, liquified petroleum gases (LPG), gasoline, light cycle oil (LCO), heavy cycle oil (HCO), and coke. Using the CH catalyst, the conversion of the bio-oil oxygenates is ca. 3 wt.% higher, while the conversion of the hydrocarbons in the mixture is lower, yielding more carbon products (83.2–84.7 wt.% on a wet basis) and less coke (3.7–4.8 wt.% on a wet basis) than the CY catalyst. The CH catalyst provides lower gasoline yields (30.7–32.0 wt.% on a dry basis) of a less aromatic and more olefinic nature. Due to gasoline overcracking, enhanced LPG yields were also obtained. The results are explained by the high activity of the HZSM-5 zeolite for the cracking of bio-oil oxygenates, the diffusional limitations within its pore structure of bulkier VGO compounds, and its lower activity towards hydrogen transfer reactions.

Taking advantage of the excess of thermal naphthas to enhance the quality of FCC unit products

Today, many European refineries finish up with excess of low-quality thermal naphthas that are hard to be marketed and, commonly, end being absorbed by catalytic naphthas at the expense of their higher quality. In this context, we propose to investigate the suitability of co-feeding thermal naphthas, i.e. visbreaker and heavy coker naphtha, with vacuum gasoil (VGO) to the fluid catalytic cracking unit. A riser simulator reactor has been used in the experimentation and tested conditions have been: 500 and 550 °C; C/O mass ratio, 6 gcat goil−1; and, residence time, 3 − 12 s. Products have been lumped according to the fractionation made in refineries in: dry gas, liquefied petroleum gases, gasoline, light cycle oil and coke. The results reveal that the co-feeding of any of the naphthas hinders the over-cracking increasing the contents of gasoline and that it inhibits the condensation reactions that produce coke. Two main factors contribute to these results: (i) the competitive adsorption and reaction between the components of the naphthas and the VGO; and (ii) the shortening of the residence time caused by an increase of the flow when the naphtha is co-fed. It should be highlighted the variation in the composition of the gasoline produced with the blends, with overall reductions of the contents of olefins and aromatics.

Efficient Conversion of Light Cycle Oil into Gasoline with a Combined Hydrogenation and Catalytic Cracking Process: Effect of Pre-distillation

The combined hydrogenation and catalytic cracking (HCC) process is reported to be able to convert inferior light cycle oil (LCO) into high-quality gasoline efficiently. However, when the LCO rich i...

Light Cycle Oil Source for Hydrogen Production through Autothermal Reforming using Ruthenium doped Perovskite Catalysts

As the hydrogen economy is coming soon, the development of an efficient H2 production system is the first issue to focus on. In this study, a first attempt to utilize light cycle oil (LCO) feedstock is introduced for H2 production through autothermal reforming (ATR) using perovskite catalysts. From a careful characterization, it is found that LCO possesses a high content of C–H and S/N compounds with over 3–4 ring bonds. These various compounds can directly cause catalyst deactivations to lower the capability of H2 extraction from LCO. To achieve a heteroatom resistance, two different perovskite micro-tubular catalysts are designed with a Ru substitution at the B-site. The activity and stability of the Ru doped perovskite were controlled by modifying the Ru electronic structure, which also affects the oxygen structures. The perovskite with a B-site of Cr reveals a relatively high portion of active Ru and O, demonstrating an effective catalyst structure with a comparable LCO reforming activity at the harsh ATR reaction conditions. The greater stability due to the Ru in the perovskite is investigated post-characterization, showing the possibility of H2 production by LCO fuel through the perovskite catalysts.

Influence of arsenic on light cycle oil hydrodesulfurization over a CoMo catalyst

Samples of a commercial hydrotreating catalyst with different initial arsenic content were used in the study light cycle oil (LCO) feed in a hydrotreating unit operating at high pressure (350 °C, 3 MPa) to evaluate the conversion and selectivity of the catalyst in the presence of arsenic. It was determined that arsenic in the catalyst modifies the textural properties and has the strongest influence on the conversion of the HDS reaction. For the first time, evidence is provided that the arsenic replaces cobalt in CoMoS phase. The incorporation of As is proposed to occur in “edge” sites of the molybdenum sulfide disfavoring the C–S cleavage during the HDS reaction, while hydrogenation sites would be favored.

Lessening coke formation and boosting gasoline yield by incorporating scrap tire pyrolysis oil in the cracking conditions of an FCC unit

We have studied the effect of adding scrap tire pyrolysis oil (STPO) as feed or co-feed in the cracking of vacuum gasoil (VGO) using a commercial equilibrated catalyst. The cracking experiments were performed in a laboratory scale fluid catalytic cracking (FCC) simulator using VGO, STPO, or a blend of the two (20 wt% of STPO), contact time = 6 s, catalyst/feed ratio = 5, and 530 °C. The composition of the different feeds has been correlated with the yield of products and the amount-location-nature of the deactivating species (coke). Our results indicate that adding STPO increases proportionally the gasoline yield, synergistically increase the yield of light cycle oil while uncooperatively decrease the yields of heavy cycle oil and coke. We further investigated the effect on coke formation, characterizing deeply the coked catalyst and coke. In fact, the coke deposited under the cracking of STPO is more aliphatic, lighter, and located in the micropores of the catalyst. The complete analysis of the coke fractions (soluble and insoluble) have lighted the peculiar chemistry of these species as a function of the type of feed used. The results point to a viable and economically attractive valorization route for discarded tires.

Processing of secondary cracking light cycle oil by combined process

ABSTRACT The light cycle oil (LCO) produced after the secondary cracking is rich in polycyclic aromatic hydrocarbons, which is challenging to be used as a blending component of automotive diesel fuel even after hydrofining. To improve the added value of LCO, a combined process of hydrofining, fractionating, and solvent extraction was proposed. The process first hydrotreated LCO to saturate the bi- and tricyclic aromatic hydrocarbons. Then the generated hydrogenated LCO was cut into the light fraction, which was used as fluid catalytic cracking (FCC) feedstock, and heavy fraction, which was used to produce diesel fuel and chemical raw materials by solvent extraction. The process combines the conventional devices in the refinery and is an effective technology for processing and utilizing LCO.

Effect of Blending Light Cycle Oil with Marine Fuel on Ignition and Combustion Characteristics of Diesel Spray

IMO sulfur regulations are expected to increase the blending ratio of catalytic cracking fuels, such as LCO (Light Cycle Oil) and CLO (Clarified Oil), with marine fuels. The aim of this paper is to investigate whether blending those fuels can cause any specific problems.

Production of Bio-hydrocarbon from Refined-Bleach-Deodorized Palm Oil using Micro Activity Test Reactor

Catalytic cracking of vegetable oil for the production of bio-hydrocarbons had been developed. In this study, the catalytic cracking of Refined-Bleach-Deodorized Palm Oil (RBDPO) had carried out over Fluid Catalytic Cracking Unit (FCCU) equilibrium catalyst in a micro activity test reactor at 510°C under various catalyst to oil (CTO) ratio of 1.20 - 2.01 g/g. The catalytic cracking of RBDPO had produced the organic liquid product (OLP) containing bio-hydrocarbon, water, gas, and coke on the catalyst converted to CO2 during the catalyst regeneration process. The increase in CTO ratio from 1.20 to 2.01, OLP yield decreased from 80.48% to 70.12%. The OLP was separated into gasoline, light cycle oil (LCO), and heavy cycle oil (HCO) based on boiling point difference by a simulated distillation gas chromatography (SimDis GC). High gasoline fraction as 31.56% was produced at CTO of 2.01 g/g. The gasoline fraction contained olefins, aromatics, paraffin, iso-paraffins, and a small amount of naphthenes and oxygenates. The presence of chemicals in the gasoline fraction influenced the research octane number (RON) of the fuel.Keyword: bio-hydrocarbon; catalytic cracking; micro activity test reactor; RBDPO

Evaluation of sulfide catalysts performance in hydrotreating of oil fractions using comprehensive gas chromatography time-of-flight mass spectrometry

Abstract In this study, two oil fractions – straight-run diesel and light cycle oil (LCO) – and the products of their hydrotreatment with sulfide catalysts, synthesized in the pores of porous aromatic frameworks, were analyzed by comprehensive two-dimensional gas chromatography (GC) with time of flight mass spectrometry (GC × GC–TOFMS). Effective separation of numerous compounds in the analyzed multicomponent mixtures and high resolution of mass spectra of reaction products made it possible to study the features of the activity of sulfide catalysts.

Bio-oil upgrading using dispersed unsupported MoS2 catalyst

Fast pyrolysis bio-oil upgrading using a dispersed unsupported MoS2 catalyst, generated in-situ, was evaluated in a continuous flow reactor system. Light cycle oil (LCO), a typical petroleum refinery stream rich in aromatics, was selected as a reaction medium and a bio-oil-in-LCO microemulsion was used as a feeding strategy to ensure bio-oil is well distributed in LCO and suppress bio-oil polymerization especially at the reactor inlet. An aqueous solution of ammonium paramolybdate tetrahydrate was emulsified in LCO to form a stable water-in-oil microemulsion to ensure that the inorganic catalyst precursor is evenly dispersed in the feed stream. The impact of catalyst-to-bio-oil ratio on product properties, yields, oxygen removal and coke formation was investigated. Bio-oil deoxygenation as high as 90% was achieved and hydrogen consumption ranged between 316 and 723 L H2/L bio-oil within the investigated range of reaction conditions. The present work shows that an oil-phase product with significantly reduced oxygen content (0.56 wt%) and acidity (total acid number of 0.48 mg KOH/g) can be produced from bio-oils with minimal solids (coke) formation (0.8 to 1.8 g/100 g bio-oil). The experimental results demonstrate that the use of unsupported catalysts could provide a promising bio-oil upgrading alternative to conventional packed bed using supported catalysts, in which catalyst bed plugging and deactivation issues are commonly encountered.

Selective hydrocracking of light cycle oil into high-octane gasoline over bi-functional catalysts

Serial catalyst systems were evaluated on naphthalene, tetralin and light cycle oil (LCO) hydrocracking reactions. The CoMo-AY/NiMo-AY grading catalysts system presented the highest BTX content, yield and octane number of gasoline fraction. • CoMo/AY catalyst presented high selectivity of saturating naphthalene to tetralin. • NiMo/AY catalyst showed high activity of cracking tetralin into light aromatics. • A novel lumping kinetic model of naphthalene was proposed and calculated. • CoMo-AY/NiMo-AY grading catalysts was the best choice to convert LCO to gasoline. • CoMo-AY/NiMo-AY grading catalysts showed good stability and low carbon deposition. Light cycle oil (LCO) with high content of poly-aromatics was difficult to upgrade and convert, which had hindered upgrading fuel quality to meet with the standard of automotive diesel for the purpose of sustainable development. The hydrocracking behaviors of typical aromatics in LCO of naphthalene and tetralin were investigated over NiMo and CoMo catalysts. Several characterization methods including N 2 -adsoprtion and desorption, ammonia temperature-programmed desorption (NH 3 -TPD), Pyridine infrared spectroscopy (Py-IR), CO infrared spectroscopy (CO-IR), Raman and X-ray photoelectron spectroscopy (XPS) were applied to determine the properties of different catalysts. The results showed that CoMo catalyst with high concentration of S-edges could hydrosaturate more naphthalene to tetralin but exhibit lower yield of high-value light aromatics (carbon numbers less than 10) than NiMo catalyst. NiMo catalyst with high concentration of Mo-edges also presented a higher selectivity of converting naphthalene into cyclanes than CoMo catalyst. Subsequently, the naphthalene and LCO hydrocracking performances were also investigated over different catalysts systems. The activity evaluation and kinetic analysis results showed that the naphthalene hydrocracking conversion and the yield of light aromatics for CoMo-AY/NiMo-AY grading catalysts were higher than NiMo-AY/CoMo-AY grading catalysts at same condition. A stepwise reaction principle was proposed to explain the high efficiency of CoMo-AY/NiMo-AY grading catalysts. Finally, the LCO hydrocracking evaluation results confirmed that CoMo-AY/NiMo-AY catalysts grading system with low carbon deposition and high stability could remain high percentage of active phases, which was more efficient to convert LCO to high-octane gasoline.

Upgrading of heavy coker naphtha by means of catalytic cracking in refinery FCC unit

The upgrading of heavy coker naphtha under conditions of the industrial fluid catalytic cracking (FCC) unit has been investigated, with the aim of obtaining light olefins and a gasoline fraction suitable to be used in the blending of motor fuels. The experiments have been conducted in a riser simulator reactor at: 500 and 550 °C; catalyst to oil mass ratio, 6 gcat goil−1; and, contact time, 3 to 12 s. Moreover, the effect of the properties of two commercial equilibrium catalysts on the products has been also assessed. Products have been grouped in: dry gas, liquefied petroleum gases, gasoline, light cycle oil and coke. The presence of strong acid sites in the catalyst favors the formation of light olefins, yielding a 5 and 3.3 wt% of propylene and butenes, respectively, at 550 °C and 6 s. A higher content of zeolite (with moderate acid strength sites) and a bigger size of the mesopores of the matrix promote the formation of a commercially interesting gasoline fraction with a yield of 90 wt% under the same conditions, with a concentration of aromatics, naphthenes, n-paraffins, olefins and iso-paraffins of 25, 10, 28, 21 and 15 wt%, respectively, and a RON of 84.

Quasi-Stop-Flow Modulation Strategy for Comprehensive Two-Dimensional Gas Chromatography.

An easy-to-implement strategy of differential flow modulation for comprehensive two-dimensional gas chromatography was innovated. With this approach, an independent auxiliary pneumatic control device for flow modulation was not a prerequisite. The strategy involved splitting the carrier gas stream into two separate streams before reaching the inlet embodiment. One stream was employed as a mobile phase for chromatographic separation. The other stream, for flow modulation, was routed to one of the ports of a three-way solenoid valve. The modulation stream flowed onward to a fluidic path and a T-junction that joined the primary and secondary dimension columns. With this arrangement and depending on the configuration of the three-port valve, the analytical platform can be operated in three different modes: bypass stop-flow, vent stop-flow, and quasi-stop flow. Quasi-stop-flow mode was demonstrated to have a significantly better chromatographic performance, as demonstrated in various types of real-life petroleum samples such as gasoline and light cycle oil. In the light cycle oil sample, a respectable separation between compound classes was achieved with peak width at half height of 34 ms or less for alkanes on a second dimension with polyethylene glycol stationary phase. Excellent repeatability was shown with normal alkanes standards of nC8-nC25. Relative standard deviations for retention times are almost zero in 1D, less than 0.2% in 2D, and less than 3.5% for peak areas (n = 9).

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

The study of a light cycle oil (LCO) upgrading alternative involving hydrotreating and hydrocracking/transalkylation procedures for obtaining a benzene, toluene and xylene (BTX) enriched fraction is presented. The research work was focused on the effect of the experimental conditions on the hydrocracking of an hydrotreated light cycle oil (HDT LCO) in order to produce the highest amounts of BTX, when the catalysts consisted of a mixture (50/50 in weight) of nickel–molybdenum on alumina (NiMo/Al2O3) and ZSM-5 materials (NiMo/ZSM-5 (50)). It was found that 7.4 MPa, up to 375 °C, LHSV of 1.2 h−1 and a H2/Oil value of 442 m3/m3 were the optimal experimental conditions for producing an enriched BTX fraction (31%). In order to facilitate the analysis, the study was carried out considering four types of hydrocarbons as lumps for the feed and HCK products: light hydrocarbons (LHC) composed by C4–C7 non-aromatic compounds, BTX, middle hydrocarbons (MHC) consisting of C7–C10 paraffins and isoparaffins, alkylbenzenes, tetralin and naphthalene derivatives and a small amount of high molecular weight hydrocarbons (HHC). Based on this description, HDT LCO used as feedstock for the hydrocracking (HCK) procedure, presents a 99% of a MHC fraction. The HCK conversion, BTX selectivity and yields were obtained from the chromatographic analysis of the products. A simple kinetic model considering only the MHC conversion was carried out. The obtained activation energy confirmed the endothermic nature of the HCK process. The activity decay of the catalytic mixture was also studied by varying the time on stream.

SIMULATION OF CO-PROCESSING BIO-OIL AND VGO IN FLUID CATALYTIC CRACKING UNITS

Biofuel is a promising substitute for fossil fuels to reduce greenhouse gas emissions and to provide highly sustainable fuels. Several technical challenges are indeed present during upgrading bio-oil to transportation fuel on a large scale. Co-processing bio-oil with some petroleum fractions in existing refineries serves as an alternative method to minimise processing costs. This paper aims to evaluate the co-processing by exploring the effects of temperature, bio-oil ratios and types of bio-oil to the product yields and quality in a Fluid Catalytic Cracking (FCC) unit within a refinery complex. The considered bio-oil are produced from pyrolysis of Palm Kernel Shell (PKS) and Empty Fruit bunch (EFB). The results show that bio-oil from PKS is better suited to produce gasoline due to its aromatic nature and its carbon range similarities compared to that from EFB. A mixture of 20% of hydrodeoxygenated (HDO) PKS in vacuum gas oil (VGO) shows a 5% improvement of naphtha yield while 20% raw bio-oil from PKS produces 4% increase in light cycle oil (LCO) yield.
 Keywords: co-processing, fluid catalytic cracking, bio-oil, palm kernel shell, empty fruit bunch, simulation

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

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.

Scrap tires pyrolysis oil as a co-feeding stream on the catalytic cracking of vacuum gasoil under fluid catalytic cracking conditions

The co-feeding of scrap tires pyrolysis oil (STPO) on the catalytic cracking of vacuum gasoil (VGO) has been investigated with the aim of exploring the capacity of the refinery fluid catalytic cracking (FCC) unit to upgrade discarded tires at large-scale. The runs have been carried out in a CREC (Chemical Reactor Engineering Centre) riser simulator reactor that mimics the behavior of the industrial unit at the following conditions: 500–560 °C; catalyst/oil ratio, 3–7 gcat goil−1; contact time, 6 s. Obtained results with the blend of 20 wt% STPO in VGO have been compared with those obtained in the cracking of the pure streams, i.e., STPO and VGO, to get a proper idea of the synergetic effects that could be involved in the co-feeding. This way, when the STPO is co-fed with the VGO the production of naphtha (C5–C12) and light cycle oil (C13–C20) lumps are maximized, as the over-cracking reactions that convert them into gaseous products (C1–C4) are mitigated. Consequently, the co-feeding promotes the production of high-interest hydrocarbons for refineries. Additionally, the naphtha obtained in the cracking of the blend shows a lower content of paraffins and naphthenes than that obtained with the VGO, and higher of olefins and aromatics.

Extractive separation of tetralin-dodecane mixture using tetrabutylphosphonium bromide-based deep eutectic solvent

Separation of components of light cycle oil (LCO) into aromatic-rich and nonaromatic-rich fractions is the essential step for upgrading LCO to produce benzene, toluene, xylene enriched fraction, and high-quality diesel. In this work, extractive separation of model LCO which contains 70 wt% tetralin and 30 wt% dodecane was performed using deep eutectic solvent (DES) as the extractant and water as the anti-extractant. Tetrabutylphosphonium bromide (TBPB) and levulic acid (LA) at a molar ratio of 1:4 was determined as the extractant, due to its high and stable performance during extraction and regeneration processes. The liquid-liquid equilibrium data of ternary systems involving TBPB:LA(1:4) were then experimentally determined and fitted using non-random two-liquid model. The continuous extraction process was simulated and optimized, high mass purity (0.980 for tetralin and 0.987 for dodecane) and high recovery ratio (0.994 for tetralin and 0.954 for dodecane) were achieved.

Various Ways for Increasing Production of Middle Distillate

Currently, refiners are experiencing a big challenge due to the slow economic growth, over diesel production and decreased demand of it. Refineries are searching for technologies that could reduce diesel output, particularly the inferior light cycle oil (LCO) fraction. Here in, this article mainly we will describes the industrialized technologies for LCO processing such as LCO upgrading, LCO blending into available plants such as fluid catalytic cracking (FCC), and hydro-refining/treating unit, LCO moderate hydrocracking, and LCO to some aromatic rich stream and also with gasoline with the integration of selective hydro-refining and resulting optimized FCC unit. It is analyzed that the LCO moderate hydrocracking can provide more gasoline at the expense of high H2 consumption, while LCO to aromatics and gasoline (LTAG) technology needs more steps for clean fuel production and retrofitting of FCC plant. Based on the analyses of current technologies, it is suggested that implementation of such technologies should consider the configuration of refineries, as well as the benefit of end users.