Equilibrium Catalyst Research Articles

Mix Design and Moisture Susceptibility of Asphalt Concrete Mixes Containing Waste Catalyst from Oil Refineries

The main objective of this study was to investigate the potential of using spent catalysts produced from the process of refining crude oil as a constituent material in hot mix asphalt (HMA). Two types of spent catalyst; equilibrium catalyst (ECat) and zeolite catalyst (ZCat) were used to partially replace some selected sizes of aggregate in the HMA. Chemical analysis of the raw catalysts indicated that both catalyst types used in this study comprised mainly of Al_2O_3 and SiO_2. Marshall Method of mix design was followed to determine the optimum asphalt content of the aggregate structure containing waste catalyst. Volumetric and stability data indicated that there is a good potential for using spent catalyst in road applications. Environmental analysis and moisture damage potential were also carried out to further characterize the designed mixes. It was observed that the level of all toxic elements in both ECat and ZCat spent catalysts samples were within the acceptable limits. ECat mixes proved to be less susceptible to moisture damage compared to the ZCat mixes. For the amounts of catalyst used in this study, the ZCat mixes failed to meet the moisture resistance requirements of 80% retained strength and hence it is not recommended to be utilized as a filler material.

FCC coprocessing oil sands heavy gas oil and canola oil. 1. Yield structure

Abstract Reducing the carbon footprint or GHG emissions is a major challenge during the production and processing of Canadian oil sands bitumen for clean transportation fuels. Co-processing bitumen derived feeds and biomass may provide an alternative solution since the level of GHG emissions for producing renewable biofuels is considered significantly lower than that for fossil fuels. In many developed countries, it is required that biofuels replace from 6% to 10% of petroleum fuels in the near future. Co-processing biomass and bitumen feeds can use existing refining infrastructure and technologies, saving capital and operating costs. In addition, co-processing may generate synergies that improve gasoline and diesel qualities. The current study investigates the catalytic cracking performances of pure heavy gas oil (HGO) derived from oil sands synthetic crude and a mixture of 15 v% canola oil in HGO using a commercial equilibrium catalyst under typical FCC conditions. Cracking experiments were performed using a bench-scale Advanced Cracking Evaluation (ACE) unit at fixed weight hourly space velocity (WHSV) of 8 h−1, 490–530 °C, and catalyst/oil ratios of 4–12 g/g. Higher conversion, dry gas yield, and liquefied petroleum gas (LPG) yield were observed at a given catalyst/oil ratio when cracking the HGO/canola oil blend compared with pure HGO. The increase in dry gas yield can be attributed to the decarboxylation and decarbonylation reactions in the presence of triglycerides composed of fatty acids in the feed, leading to the formation of CO2 and CO. In general, at a given conversion, the addition of canola oil resulted in lower gasoline yield at the expense of water formation. As well, lower coke yield was observed for the blend. The relatively high nitrogen content in the feeds played an important role in catalyst activity and selectivity, particularly at low reaction temperatures.

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

The distribution of products in the range of gasoline and middle distillate cuts obtained in the catalytic cracking of heavy aromatics and polycyclic aromatic hydrocarbons over a fluidized catalytic cracking (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 vacuum gas oil and residual feedstocks in the FCC process. The catalyst was used in its fresh and equilibrium forms at 450 °C in a Chemical Reactor Engineering Centre 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, naphthenic-aromatic, and polyaromatic hydrocarbons, showed catalytic conversions that increased, were relatively stable, and decreased, respectively, as a function of the reaction time. The distribution of products suggested that the most important reactions were thermal dehydrogenation, hydrogen transfer, ring opening, cracking, and condensation. It was shown that all of the model compounds are cracked, yielding particularly benzene in the gasoline range and coke.

Hydration of the equilibrium catalyst (Ecat) calcium hydroxide system

The pozzolanic properties of an equilibrium catalyst (Ecat), a waste produced worldwide at fluidized catalytic cracking units of oil refineries, have been studied in cementitious matrices. The consumption of calcium hydroxide is usually taken as a mean to assess the pozzolanicity of a material, independently of the formation of the hydrated phases formed from the pozzolanic reactions. The use of thermal analysis methods allows the identification and quantification of the products formed by hydration and pozzolanic reactions, based on the loss of their chemically combined water during analysis. In the present study, TG/DTG techniques were used to quantify the amount of C-S-H, C-S-A-H, C-A-H, and calcium hydroxide in lime-Ecat pastes, containing up to 40 % of Ecat, aged for 1–28 days. The influence of the content of these phases on the mechanical properties of the resulting samples was also investigated by axial compression. The results confirmed the pozzolanic activity of Ecat, from the measurement of calcium hydroxide consumption, associated with the formation of the hydrated phases, which increased with hydration time.

Conversion of rapeseed oil via catalytic cracking: Effect of the ZSM-5 catalyst on the deoxygenation process

In the present paper rapeseed oil was considered as a potential biomass-based source of motor fuels and petrochemicals. The conversion of pure rapeseed oil and its mixture with hydrogenated vacuum gas oil (HVGO) under simulated fluid catalytic cracking conditions via MAT-test was investigated. Besides inorganic gases (CO, CO2) and water there were also organic oxygenated compounds (alkylphenolics, carboxylic acids etc.) found in the organic phase of the liquid product. For their removal we proposed to improve the catalytic system consisting predominantly of pure standard FCC equilibrium catalyst by the ZSM-5-based FCC catalyst additive. The extent of liquid product deoxygenation and the yield of gasoline were the main monitored parameters. The use of the catalyst mixture containing 10wt.% of ZSM-5 catalyst additive and 90wt.% of the standard FCC-catalyst in the case of pure rapeseed oil resulted in a practically complete removal of the organic oxygenates from the liquid product. In the case of the feed mixture rapeseed oi–-vacuum gas oil (1:9) there was found virtually no organic oxygenates in the liquid product with the gasoline yield close to the one of the pure HVGO cracking.

Dendritic nickel porphyrin for mimicking deposition of contaminant nickel on FCC catalysts

Nickel-containing molecules are a naturally occurring component of heavy crude oils. During fluid catalytic cracking (FCC) of heavy (resid) crudes, nickel is deposited on the catalyst toward the periphery of the particle forming a characteristic distribution pattern and subsequently acts as a dehydrogenation catalyst contributing to increased hydrogen and coke yields. Here we describe a statistical SEM analysis of several equilibrium catalysts (Ecats) that confirms the formation of such peripheral deposition but reveals the natural variation of this deposition profile, ranging from a nearly uniform distribution to as much as five times more nickel on the periphery, as compared to the core of the same catalyst particle. Nickel is often added to the catalyst prior to conditioning and testing to mimic the effects of metal deposition in resid-FCC operation. The most common method of metal deposition is through incipient wetness impregnation using nickel naphthenate; a molecular species significantly smaller than the nickel-containing molecules found in crude oil. Reproducing the characteristic shell-type deposition profile of nickel has proved difficult and solutions to do so effectively are needed. Here, we describe the design and synthesis of a novel dendritic nickel porphyrin, NiTCPPA (meso-tetrakis-(phenyl-4′-{ditert-butyl-4-caboxamido-4-(3-tert-butoxy-3-oxopropyl)heptanedioate}porphyrin) nickel (II)) that has a larger molecular cross section and can be used to recreate in the laboratory, the naturally occurring peripheral deposition profile of nickel.

Iron Contamination Mechanism and Reaction Performance Research on FCC Catalyst

FCC (Fluid Catalytic Cracking) catalyst iron poisoning would not only influence units’ product slate; when the poisoning is serious, it could also jeopardize FCC catalysts’ fluidization in reaction-regeneration system and further cause bad influences on units’ stable operation. Under catalytic cracking reaction conditions, large amount of iron nanonodules is formed on the seriously iron contaminated catalyst due to exothermic reaction. These nodules intensify the attrition between catalyst particles and generate plenty of fines which severely influence units’ smooth running. A dense layer could be formed on the catalysts’ surface after iron contamination and the dense layer stops reactants to diffuse to inner structures of catalyst. This causes extremely negative effects on catalyst’s heavy oil conversion ability and could greatly cut down gasoline yield while increasing yields of dry gas, coke, and slurry largely. Research shows that catalyst’s reaction performance would be severely deteriorated when iron content in E-cat (equilibrium catalyst) exceeds 8000 μg/g.

Use of ZSM-5 catalyst in deoxygenation of waste cooking oil

AbstractThis study investigated the potential use of waste cooking oil (WCO) in the production of engine fuels and valuable chemicals via catalytic cracking. WCO was processed in its pure form and in a mixture with hydrotreated vacuum gas oil (HVGO). Catalytic cracking experiments were performed using a microactivity test (MAT) (simulation of the fluid catalytic cracking environment). In cracking over the standard fluid catalytic cracking equilibrium catalyst (FCC-ECAT), the oxygen contained in the feed was consumed in the formation of CO and CO

Formation of aromatics in heavy gasoline and light LCO ends in FCC

Decalin, a naphthenic bicyclic compound, was reacted over a commercial FCC catalyst in its fresh, equilibrium and three dealuminated forms in order to analyze the formation of aromatic hydrocarbons in the gasoline and LCO cuts, heavy and light ends, respectively. A batch, fluidized bed CREC Riser simulator laboratory reactor was used at 450°C with short contact times from 1 to 8s. The dealuminated catalysts showed an activity intermediate between those of the fresh and equilibrium catalysts, which can be correlated to zeolite content and acidity. Also those properties, at least in the range of values observed in this work, seem to be the most important characteristic in controlling the selectivity of the set of reactions. A reaction network was described, where hydrogen transfer reactions are considered to be the most important to form aromatics, a fact which is essentially unavoidable when a bicyclic naphthenic is converted on these catalysts. Aromatic belonged mainly to the gasoline boiling point range and, to a lower extent, to LCO.

Advanced developments: Cracking catalysts and additives to them

This paper is devoted to the cooperative works of the Institute of Hydrocarbon Processing (Siberian Branch, Russian Academy of Sciences) and JSC Gazprom Neft-Omsk Refinery on the creation of cracking catalysts and additives to them with the purpose of increasing the yield of C3-C4 olefins, reducing the concentration of sulfur compounds in the gasoline product, and ensuring the afterburning of CO during the regeneration of a catalyst. Bizeolite cracking catalysts, which give yields of C3-C4 olefins of no less than 30 wt % and allow us to vary the composition and yield of target reaction products within wide ranges, are developed. Mixed oxides or modified Y and/or ZSM-5 zeolites are proposed as cracking catalyst additives that result in a 35% reduction in the concentration of sulfur compounds in gasoline (as compared to an equilibrium catalyst). A manganese oxide based additive is proposed for the efficient afterburning of CO, and a pilot batch of this additive is produced by JSC Gazprom Neft-Omsk Refinery and tested at an industrial plant. It is shown that the amount of manganese oxide based additive required to ensure a residual CO concentration of less than 20 ppm is 20% lower than for a platinum-containing additive. The developed catalysts and additives to them can be synthesized on the basis of the catalysts produced at JSC Gazprom Neft-Omsk Refinery.

Catalytic Cracking of C2–C3 Carbonyls with Vacuum Gas Oil

The fluid catalytic cracking (FCC) route could be considered for the co-processing of biomass-derived pyrolysis oil with petroleum-derived vacuum gas oil (VGO) in a typical refinery unit by integrating it with a biomass fast pyrolysis process. This paper aims to study the effect of co-processing pyrolysis oil representative model compounds (C2–C3 carbonyls such as hydroxyacetone and glycolaldehyde dimer) with VGO in a FCC advanced cracking evaluation (ACE-R) unit, using an industrially available FCC equilibrium catalyst (E-CAT). The blending ratios of C2–C3 carbonyls and VGO were varied from 5:95, 10:90, 15:85, and 20:80. The reactor was operated in close to industrial FCC process at a temperature of 530 °C and atmospheric pressure with a catalyst-to-oil ratio of 5.0. The blended FCC feedstock and their liquid distillates were structurally characterized by 1H and gated decoupled 13C NMR techniques. The average structural parameters like branchiness index, substitution index, average length of alkyl chains, and fraction of aromaticity per molecule was obtained from NMR data. A linear increase in FCC conversion was observed with increase in hydroxyacetone blending ratio with VGO from 5% to 20%, which may be due to an increase in propylene and a decrease in heavy cycle oil. Increasing the glycolaldehyde blending ratio from 5% to 10% increased the FCC conversion, while the conversion decreased at ratios of 15% and 20%. The 1H NMR and 13C NMR data indicated that there is an increase in the amount of monoaromatics with increases in the amount of hydroxyacetone, whereas in the case of glycolaldehyde, the monoaromatics increased for blending ratios up to 10% and decreased upon further increases in blending ratio. The equilibrium FCC catalyst is capable of cracking oxygenates presents in pyrolysis oil such as hydroxyacetone and glycolaldehyde toward the production of liquefied petroleum gas (LPG) range products. Furthermore, a scheme has been proposed for the processing of pyrolysis oil in petroleum refinery units.

Study of factors affecting the erosive wear of equipment for dehydrogenation units in fluidized beds of microspherical chromia-alumina catalysts under industrial operating conditions

The main problems associated with the operation of microspherical treating-type chromia-alumina catalysts with increased strength during isoparaffin dehydrogenation are discussed. The erosive wear of the walls of overflow pipelines when using a mixture of treating-type KDI and conventional IM-2201S catalysts and ways of solving the problem are emphasized. It is found that the main reason for an increase in erosive wear is the greater momentum of catalyst particles due to a higher mean particle size and gas transport rate; upon transitioning from IM-2201S to a mixture of IM-2201S and KDM (70 : 30), the mean particle size of the equilibrium catalyst grows from 68 to 74 μm. The optimum size range of a high-strength catalytic system in which the activity does not increase over time is calculated with a lower rate of transport gas injection while keeping the number of particles 20–40 μm in size at 20–30 wt %. Pilot batch production of high-strength catalyst in the optimum size range is recommended in order to shift units for the industrial dehydrogenation of isobutane to the use of treating-type KDI catalyst without the addition of IM-2201S.

Development of new deactivation method for simulation of fluid catalytic cracking equilibrium catalyst

Selection of a good catalyst is the easiest way to increase profitability of a fluid catalytic cracking (FCC) unit. During operation, these catalysts get deactivated due to operation at high temperatures, steam and deposition of metals on the catalyst. Developing a proper catalyst deactivation method is crucial for optimization of a good catalyst for FCC. Conventional laboratory deactivation procedures include direct metal impregnation method, cyclic deactivation method (CDM) and cyclic propylene steaming (CPS). Direct metal impregnation method gives higher coke and gas yields. CDM and CPS methods implementation is very difficult and time-consuming and there is a deviation in coke and gas yield. New rapid deactivation method has been developed to simulate plant equilibrium catalyst (E-Cat) by modifying metal impregnation, steaming and oxidation/reduction procedures. The E-Cat generated through a new deactivation method was characterized for physico-chemical properties using X ray diffraction (XRD), temperature-programmed reduction (TPR), and SEM-EDX and activity studies. XRD studies show that metals are dispersed well on catalyst samples. SEMEDX studies reveal that the morphology of simulated E-Cat and plant E-Cat catalyst particles appear to be same. E-Cat obtained by new deactivation method gives better coke and gas yields. Two E-Cats were also generated through CDM and direct metal impregnation method for comparing with the one generated through new method. New deactivation method also significantly reduces the evaluation time and is cost-effective. New deactivation method is developed for the simulation of fluid catalytic cracking equilibrium catalyst in laboratory. New deactivation method significantly reduces catalyst evaluation and selection time and is more cost-effective.

Catalytic Cracking of Glycerol to Fine Chemicals over Equilibrium Fluid Catalytic Cracking Catalyst

Effective conversion of glycerol into fuels and chemicals is an emerging field in terms economic viability of first generation bio- fuels development. In the present work the refinery fluid catalytic cracking (FCC) process is used to convert the biomass -derived glycerol into possible fine chemicals through a series of reactions like dehydration, cracking and hydrogen transfer. The catalytic cracking of biomass–derived glycerol have been carried out using industrially available fluid catalytic cracking equilibrium catalyst (E-CAT) in an advanced cracking evaluation (ACE-R) FCC unit for temperatures ranging from 350 to 550°C. The catalyst-to-oil (C/O) ratio was kept constant at 5wt.%. At higher temperatures (430-550°C) 100% glycerol conversion and 50% of acetaldehyde yield was obtained with E-CAT. The maximum yield of acrolein was found to be 7.61% at 430°C temperature; whereas the yield of acetaldehyde was increased with increase in temperature and it was higher at 550°C. The gas and liquid products have been analyzed using gas chromatography (GC) and nuclear magnetic resonance (NMR) spectroscopy techniques, respectively. Carbon dioxide produced in the regeneration process was analyzed using infrared (IR) spectroscopy. Further in the liquid product, in addition to acetaldehyde and acrolein, light olefins and aromatics were also found.

Catalytic cracking of pyrolysis oil oxygenates (aliphatic and aromatic) with vacuum gas oil and their characterization

In the present work an attempt has been made to study the effect of catalyst-to-oil ratio (C/O) on the product distribution for the catalytic cracking of mixture of vacuum gas oil (VGO) with guaiacol and acetic acid, which are the representative model compounds of the biomass-derived fast pyrolysis oil. The catalytic cracking of mixture of VGO has been carried out using industrially available FCC equilibrium catalyst (E-CAT) in an advanced cracking evaluation ACE-R FCC unit. The FCC feed, distillates and liquid products are analyzed using Fourier transform infrared spectroscopy, and structurally characterized by 1H, gated decoupled 13C NMR methods. The average structural parameters like branchiness index, substitution index, average length of alkyl chains, and fraction of aromaticity per molecule are obtained from NMR data. The SIM distillation based product analysis indicated that the presence of guaiacol increased the product selectivity of gasoline fraction; whereas the presence of acetic acid clearly increased the yield of light olefins, CO and CO2. The 1H and 13C NMR data indicated that the fraction of aromaticity for both Feed B (vacuum gas oil+acetic acid) and Feed C (vacuum gas oil+guaiacol) increased, after catalytic cracking, with increase in C/O ratio from 3 to 9. The equilibrium FCC catalyst is able to crack oxygenates presents in pyrolysis oil such as acetic acid and guaiacol. Further the crackability pattern of pyrolysis oxygenates supported by the vibrations of CO and OH absorption peaks (of FTIR) and NMR data of liquid product.

Consumption of calcium hydroxide and formation of C–S–H in cement pastes

The pozzolanic properties of the equilibrium catalyst (Ecat), an abundant waste from fluid catalytic cracking units of oil refineries, have been studied in cementitious matrices. The consumption of calcium hydroxide is usually taken as a means to assess the pozzolanicity of a material, ignoring the formation of C–S–H and other hydrates, the main product of the pozzolanic reaction. The use of thermal analysis methods allows the identification and quantification of the products of the hydration reaction, based on the loss of chemically combined water of phases present in a cementitious matrix. In the present study, TG/DTG techniques were used to quantify the amount of C–S–H + ettringite, C–A–S–H + C–A–H, and calcium hydroxide in cement–Ecat pastes, containing 0–40 % Ecat, aged for 1–28 days. The influence of the content of these phases on the mechanical properties of the resulting samples was also investigated by axial compression. The results further confirmed the pozzolanic activity of Ecat, so that the production of C–S–H and C–A–S–H increased with the aging time, but in a smaller amount than in the reference paste. The compressive strength test showed that the pastes containing 10 % Ecat, aged for 14 and 28 days, presented improved properties as compared to the corresponding references.

Reactivity of the saturated, aromatic and resin fractions of ATR resids under FCC conditions

SARA (saturate, aromatic, resin and asphaltene) fractions composing an atmospheric tower resid from a naphthenic crude were separated using the ASTM 2007 method. Two commercial equilibrium catalysts, of the conventional and resid types, were used to convert the aromatic, resin and saturate fractions under conditions of the FCC process. The reaction experiments were performed in a CREC Riser Simulator reactor. Reaction temperature was 550°C, reaction times were from 5 to 20s, the catalyst mass was 0.8g and the catalyst to oil relationship was 5.0. The various fractions were used dissolved in toluene at 20wt.%. The hydrocarbon reaction products were grouped into dry gas, LPG, compounds in the gasoline and LCO boiling ranges and coke. All the fractions converted almost completely, but differences in the yields of the main hydrocarbon groups were observed which revealed the fractions’ nature.

Catalytic Cracking Law of Recycle Oil over Equilibrium Catalyst

Catalytic cracking experiment of recycle oil was carried out in fixed fluidized bed apparatus. The effects of reaction temperature, catalyst to oil ratio and space time on product distributions were investigated. Low conversion of recycle oil was exhibited due to poor cracking performance, moreover, reaction conditions showed obvious influence on gasoline yield.

Catalytic conversion of C4 fraction for the production of light olefins and aromatics

The catalytic conversion of the C4 fraction from a fluid catalytic cracking (FCC) unit over a commercial FCC equilibrium catalyst was investigated using a confined fluidized bed reactor system. Butenes were easier to convert than butanes, and 1-butene was the easiest to convert among the butene isomers. The ethene and propene yields increased with increased reaction temperature and decreased with increased weight hourly space velocity (WHSV). The formation of propene involved two successive steps: butene dimerization and large hydrocarbon cracking. Aromatics were formed by the aromatization of the intermediate large olefins. A mechanism parameter RCA was proposed to describe the relative function of the cracking reaction to the aromatization reaction. RCA increased with increased reaction temperature and decreased with increased WHSV. The cracking reaction predominates on the aromatization reaction at high reaction temperatures.

Commercial additives for sulfur control in FCC gasoline: Overall analysis of their impact on LCO and gasoline

Experiments with a commercial equilibrium catalyst and mixtures with a commercial additive for sulphur reduction in gasoline were performed in a CREC Riser Simulator reactor to study the impact of three different proportions of the additive in the overall performance of FCC units. The experiments were performed under conditions similar to those of the industrial operation (510̊C, CAT/OIL 6.4). The reaction effluents were analyzed by on-line gas chromatography using two detectors simultaneously: FID for hydrocarbons and PFPD for sulfur compounds. The highest reduction of sulfur in gasoline (about 10%) without yield penalties was obtained with the smallest amount of additive (10wt.%); however, the reduction of sulfur in LCO was the least. At higher amounts of additive (40wt.%) the effectiveness in reducing sulfur in gasoline was lower, but the sulfur reduction in LCO was higher (about 5%). Reducing the gasoline endpoint obviously reduced sulfur not only in the cut, but also in LCO. This positive effect was improved when the gasoline was produced with catalyst–additive mixtures, though a penalty in gasoline yield was observed. If the endpoint reduction of gasoline is very severe, it did not generate a more significant reduction of sulfur in gasoline an LCO, even when additives were present.