Spent FCC Catalysts Research Articles

High-Temperature Rheological Properties of Asphalt Mortar Modified with Spent FCC Catalysts

Spent fluid catalytic cracking catalysts (S-FCC-Cs) constitutes a fraction of the hazardous solid waste generated in the petrochemical industry. The resource application of S-FCC-Cs remains a challenge. This study aims to explore utilizing S-FCC-Cs in asphalt mortar as a means to enhance resource utilization. Five different S-FCC catalysts were used as substitutes for mineral powder in the asphalt slurry at varying proportions. The high-temperature rheology of the resulting spent FCC catalyst-modified asphalt slurry was analyzed using temperature scanning tests and multiple stress creep recovery (MSCR) tests conducted at different temperatures and substitution doping levels. As the proportion of alternative doping increased, both the phase angle and irrecoverable creep flexibility decreased, while the absolute values of the rutting factor, deformation recovery rate, and irrecoverable creep flexibility difference increased. Moreover, as the temperature rose, the phase angle increased while the rutting factor decreased. The inclusion of an alternative admixture significantly improved the high-temperature performance of the asphalt mastic. This improvement was attributed to several factors, including the increase in the elastic component, enhanced deformation resistance, and improved deformation recovery. While the high-temperature performance of spent FCC catalyst-modified asphalt mastic gradually declined with increasing test temperature, all performance indices remained superior to those of limestone mineral powder asphalt mastic. In addition, the asphalt mortar modified by S-FCC-C JX with a surface area and hydrophilic coefficient of 105 m2/g and 1.026, respectively, exhibited the best rutting resistance and resilience performances among the five mortars, suggesting that the two factors co-affected the high-temperature rheological properties of S-FCC-C asphalt mortar. Considering stress sensitivity, it is more advantageous in improving the high-temperature deformation resistance of asphalt slurry at the JX dosage of 20%. These research findings offer valuable guidance for the application of S-FCC catalysts in asphalt pavement.

Regeneration method for spent FCC catalysts: Brief Review

Regeneration method for spent FCC catalysts: Brief Review

Selective recycling of BTX hydrocarbons from electronic plastic wastes using catalytic fast pyrolysis

Non-catalytic and catalytic pyrolysis of two waste electrical and electronic equipment (WEEE) fractions, with two different copper contents (low- and medium-grade WEEE named as LGE and MGE, respectively), were performed using micro- and lab-scale pyrolyzers. This research aimed to fundamentally study the feasibility of chemical recycling of the WEEE fractions via pyrolysis process considering molecular interactions at the interfaces of catalyst active sites and WEEE pyrolyzates which significantly influence the chemical functionality of surface intermediates and catalysis by reorganizing the pyrolyzates near catalytic active sites forming reactive surface intermediates. Hence, Al2O3, TiO2, HBeta, HZSM-5 and spent FCC catalysts were used in in-situ micro-scale pyrolysis. Results indicated that HBeta and HZSM-5 zeolites were more suitable than other catalysts for selective production of aromatic hydrocarbons and BTX. High acidity and shape selectivity of zeotype surfaces make them attractive frameworks for catalytic pyrolysis processes aiming for light hydrocarbons like BTX. Meanwhile, the ex-situ pyrolysis of LGE and MGE were carried out using HZSM-5 in micro- and lab-scale pyrolyzers to investigate the effect of pyrolysis configuration on the BTX selectivity. Although the ex-situ pyrolysis resulted in higher formation of BTX from LGE, the in-situ configuration was more efficient to produce BTX from MGE.

Effect of lanthanum content on physicochemical properties and thermal evolution of spent and beneficiated spent FCC catalysts

Two FCC spent catalysts with different amounts of La2O3 and similar Al2O3/SiO2 ratios and the corresponding residues of an optimized process of La-extraction are studied. The potential of the powders as feedstock for mullite refractories is established. The four powders have been fully characterized – chemical composition, crystalline phases, particle size, specific surface area, porosity, and morphology. Their thermal evolution up to 1500°C has been studied using dynamic techniques – hot stage microscopy, DTA-TG – and isothermal thermal treatments. The effect of powder characteristics on high temperature phase development, in particular, on mullite formation is discussed.Besides La, the La-extraction process also implies partial extraction of the matrix in which zeolites are dispersed, resulting in reduced impurities contents and Al2O3/SiO2 ratios.The powders present differences in the textural properties– porosity and specific surface area – that do not affect the high temperature behavior, which is determined by the impurities and the Al2O3/SiO2 ratio. The four powders can be proposed as precursors for mullite materials. The compositions of the spent catalysts can be envisaged for application up to 1200°C. The compositions of the residues of the La-extraction process can be proposed for higher temperatures once their composition is corrected by adding alumina to avoid extensive cristobalite formation together with mullite.

Lanthanum recycling from spent FCC catalyst through leaching assisted by electrokinetic remediation: Influence of the process conditions on mass transfer

The electrokinetic remediation assistance on the leaching of spent FCC catalysts demonstrated satisfactory performance as an alternative method to the traditional leaching method, aiming to recycle rare earth elements from this solid waste, by former studies. The present work identified the process conditions that improved the mass transfer performance of lanthanum by electrokinetic phenomena, by means of a central composite design and variance analysis. Thereby, the system that operated with the sulfuric acid concentration in the electrolyte of 1 mol/l and the applied electric field of 0.15 V/m, for 8 h of the experiment, was the best in terms of energy and acid consumption per mass of lanthanum recovered, amid the tested conditions.

Zinc oxide coated regenerated spent FCC catalyst for water purification

Introduction: Zeolites are microporous aluminosilicates, commonly used as commercial adsorbents and catalysts. As an adsorbent, zeolite can adsorb gram-positive bacteria when compared with gram-negative bacteria (1,2). Ultrafine zinc oxide nanoparticles in colloidal medium is toxic to E. coli bacteria (3). ZnO-coated zeolite adsorbent can effectively remove of humic acid and E. coli from water when compared to zeolite adsorbent (4-5). The spent FCC (SFCC) catalyst is very harmful to the human health by being absorbed mainly into the respiratory tract and lungs due to its tiny particles of size 60-100 micrometer (1). Most of the spent FCC catalysts are currently disposed as landfills, which leads to the wastage of valuable metal resources and the environmental pollution. In this work the spent zeolite catalyst is regenerated and coated with zinc oxide and this zinc oxide coated regenerated spent FCC catalyst (ZOCRSC) is used to remove E. coli from water. Methods: In this work, decoking is done to burning off the deposited carbon by roasting in air at 550°C for 2 hours. Then SFCC catalyst is leached with HCl and oxalic acid. Activated SFCC catalyst, obtained as a leaching residue is separated. Zinc oxide is coated on the regenerated catalyst to develop zinc oxide coated zeolite adsorbents. Coating procedure follows activated catalyst modified by HNO3 and then Zn(NO3)2 solution. To characterize crystal structure of zeolite and ZOCRSC, XRD, SEM, and BET analysis were carried out. The water from the treatment plant after secondary treatment was used for the experiments and the E. coli content was estimated using plate counting technique. ZOCZ is added to the E-coli containing water and after proper mixing the suspension is allowed to settle. Sample is collected from treated water at different intervals for determining E. coli content. The treatment procedure was also done using the spent coated sample, acid activated sample and spent FCC catalyst and are used as a comparison with ZOCZ. Results & Discussions: The XRD pattern shows that the ZOCRSC exhibited similar characteristic diffraction peaks to that of the uncoated samples which indicates that the modification did not affect the mineralogy of the zeolite and in addition it also exhibited similar characteristic diffraction peaks to those of ZnO. Thus, the XRD pattern and the SEM images of ZnO coated spent catalyst and ZnO coated regenerated catalyst shows that coatings of ZnO on zeolites were done effectively. The surface area and pore volume of zinc oxide coated regenerated spent FCC catalyst is determined from BET analysis. The removal of E. coli from water was quantified by plate counting. The E. coli count of the untreated water sample is 560 cfu/ml and treated sample after 30 minutes is less than 1 cfu/ml. Water treated using spent FCC catalyst without any modification did not show any change in the E. coli count. The acid activated catalyst and spent FCC catalyst coated with ZnO reduce the E. coli content in the water to 11 cfu/ml and 6 cfu/ml respectively after 90 minutes. Conclusions: ZnO coated regenerated spent FCC catalyst is developed from waste spent catalysts is utilized for the removal of E. coli from water. The ZOCRSC removes E. coli effectively when compared with spent FCC catalyst coated with ZnO, acid activated catalyst, and spent FCC catalyst in a short period. The spent FCC catalyst coated with ZnO cannot be directly used for treating purpose as it contains various contaminant metals which should not be present in treated water. Keywords: Escherichia coli, Spent FCC catalyst, Zinc oxide, ZOCRSC

Albemarle catalysts reports 1Q 2021 sales growth

The speciation of Ni in spent Fluid Catalytic Cracking catalysts is studied. Carefully performed XRD analyses with NiO/SiO2 samples used as calibration standards, demonstrate that the presence of NiO as a separate phase is reliably detected also for NiO concentration close to 0.1 wt% (1000 ppmw). Actually, both on real spent FCC catalysts (ECAT's) and on artificially contaminated industrial FCC catalysts, NiO is not detectable as a separate phase, even after contamination of the order of 15,000 ppmw of Ni. SEM–EDS experiments provide evidence of a largely preferential location of Ni on alumina particles present in the FCC catalyst mixture, thus acting as “nickel traps”. XRD, UV–vis and TPR data confirm that Ni deposits on alumina particles forming a hardly reducible surface and subsurface layer, giving rise to a solid whose composition is NixAl2O3+x with x << 0.25. As a result of this, the formation of extended Ni metal particles in the raiser reactor is avoided, being their unwanted dehydrogenation activity essentially eliminated. The absence of bulk NiO in the spent FCC catalysts (at least when Ni content is in the range 2000–10,000 ppmw) allows the classification of this material as a non-hazardous waste.

Removal of Hg0 from simulated coal-fired flue gas by using activated spent FCC catalysts

The spent fluid catalytic cracking (SFCC) catalysts were activated by an “internal instant vaporization (IIV)” method and used in the removal of Hg0 from a simulated flue gas in a fixed bed reactor; the effect of various operation parameters such as the SFCC activation conditions, adsorption temperature, and flue gas components on the Hg0 removal efficiency was investigated. The results indicate that the SFCC catalyst activated with methanol or ethanol performs adequately in terms of Hg0 removal, whilst the calcination temperature also has a great influence on the activation of the SFCC catalyst. O2 in the flue gas favors the Hg0 removal, whilst NO facilitates the oxidation of mercury and displays a positive effect on the mercury removal in the presence of O2, accompanying with the formation of N-containing active species on the activated SFCC catalyst surface. SO2 in the flue gas, depending on its concentration, may exert the effect of catalytic adsorption or competitive adsorption on the Hg0 removal. Approximately 100% Hg0 can be removed in the stream of 6% O2, 12% CO2 and 0.06% NO at 120°C by using the activated SFCC catalyst with ethanol as an organic solvent and calcined at 120°C, suggesting that the spent FCC catalysts after activation can be a potential adsorbent for the removal of Hg0 from the coal-fired flue gas.

The potential of La-containing spent catalysts from fluid catalytic cracking as feedstock of mullite based refractories

The potential of La-containing spent FCC catalysts as feedstock of mullite refractories is discussed. A simple methodology to determine the maximum use temperatures is proposed. It combines the analysis of the microstructural evolution with temperature with strain-controlled (2 × 10−4s-1 to 3% maximum strain) and constant stress compressive creep tests at high stresses (15−30 MPa) at 1100–1200 °C. Complete reaction was assured by milling the waste before processing mullite materials. Phase and microstructural evolutions with temperature were established combining dynamic techniques (DTA-TG and dilatometry) with quenching experiments. Isothermal treatments at 1300 and 1400 °C allowed selecting the optimum thermal treatment: 1400 °C-3 h.The formation of a La2O3 rich Al2O3-SiO2 liquid at low temperatures ≈1200 °C leads to the development of a microstructure constituted by a skeleton of mullite tabular grains trapping the remaining glass. Such microstructure endows the material with sufficient creep resistance at temperatures 1100−1200 °C to be used as constituent of refractories for temperatures ≤1200 °C.

Removal of sulfur compounds from LPG by heteropoly acid‐modified spent FCC catalyst

Modified spent FCC catalysts were prepared and the desulfurization properties of these adsorbents were examined in this paper. The experiment data indicated that the spent FCC catalyst performed well in desulfurization after modification; the sulfur content in the liquified petroleum gas (LPG) dropped down to 5~10 mg.m−3. X‐Ray Fluorescence, X‐ray diffraction, Nitrorms and Fourier transform infrared were applied to characterize these adsorbents. Results showed that the content of various metals in spent FCC catalyst was significantly higher than fresh catalyst; and the metals which deactivated the FCC catalysts became the active sites for desulfurization. In addition, a moderate amount of Lewis acid sites is advantageous to desulfurization while too many Lewis acid sites played a negative role.

Adsorption and mechanistic study for phosphate removal by magnetic Fe3O4-doped spent FCC catalysts adsorbent

The waste materials utilization has attained increasing attention due to the generation of a large number of spent materials. In the current study, a practical magnetic adsorbent (Fe3O4-doped spent Fluid Catalytic Cracking catalysts, abbreviated as FCCx@(Fe)y-O) was prepared, liable to be separated. The batch experiments were employed to investigate the phosphate removal behavior. The findings of this study demonstrated that FCC4@(Fe)1-O exhibited the best phosphate removal performance among the adsorbents (FCCx@(Fe)y-O), attributed to rough surface layer, i.e., composed of active sites. The various characterizations results revealed that the adsorption behavior of FCC4@(Fe)1-O followed the inner-sphere adsorption based on ligand exchanges mechanism. Furthermore, OH− played an important role in the adsorption process. Minor effects were showed on the phosphate removal in the experiments of commonly coexisting anions, except CO32− and SiO32−. The above findings affirmed that FCC4@(Fe)1-O was a suitable adsorbent for phosphate removal in the practical application.

Synthesis and Characterization of Zeolites from Spent FCC Catalysts

Fluid catalytic cracking is one of the major secondary conversion process in petroleum refinery. Nowadays, the spent fluid catalytic cracking catalysts (FCCCs) are disposed of in landfill or stocked for a long period. Environmental risks and lack of space suggest that the management of FCCCs needs to be reviewed. The FCC catalysts contain about 3-3.5 %wt. of rare earth (RE) oxides; rare earth elements (REEs) are important for stabilization of the matrix of FCC catalysts. The main challenge is to develop an efficient process based on recovery of REEs and reuse of the solid leaching residue for some applications. In this paper a new process is proposed to recover cerium and lanthanum from FCCCs combined with reuse of the leaching solid residue for the production of synthetic zeolites. Three different zeolites were synthesized by using the solid residues from hydrochloric, nitric and sulfuric acid leaching. The chemical and physical properties of zeolites were characterized by different spectroscopic techniques including Scanning Electron Microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDS) for evaluating the surface morphology. The X-Ray Diffraction (XRD), the Brunauer–Emmett–Teller (BET) and Infrared Spectroscopy (FT-IR) analyses were used to characterize the structure of such zeolites. In addition, the X-ray Fluorescence (XRF) was used to identify the chemical composition. Zeolite is a solid porous material widely used as adsorbent in different processes, particularly applied to wastewater treatments. In this paper, adsorption of heavy metals onto zeolites were investigated by Inductively Coupled Plasma - Optical Emission Spectroscopy (ICP-OES). The best results in terms of metal removal were achieved by the zeolite synthesized from the sulfuric acid leaching residue.

Towards efficient extraction of La(III) from spent FCC catalysts by alkaline pre-treatment

In Vietnam, Dzung Quat Refinery disposes about 7300 tonnes of spent fluid catalytic cracking (SFCC) catalysts per year. The recovery of rare earth metals (La(III), Ce(III),…) contained in SFCC catalysts using acid leaching process has attracted much attention of scientific community. In this study, the effect of alkaline pre-treatment of spent catalysts prior to the acid leaching process on the leaching yield of La(III) was investigated. The results showed that alkaline pre-treatment caused zeolite destruction, which had a positive effect on the leaching of La(III). High leaching yields of La(III), 80% and 86%, were achieved when the SFCC catalysts were pre-treated with NaOH and NH3, respectively, before leaching with 2 M HNO3 solution at 50 °C. These results were comparable with the one obtained from the sample that was leached by 7 M HNO3 at 50 °C without the initial alkaline pre-treatment. NH3 pre-treatment significantly enhanced the zeolite destruction in the SFCC catalysts and increased La(III) leaching yield compared to the NaOH pre-treatment. It is likely due to NH3 interactions with contaminant metals (e.g. Ni, V, and Fe), which were deposited on catalysts during cracking process.

Minimization of Waste Spent Catalyst in Refineries

Solid catalytic materials play major role in oil refining industry. There are various types of catalysts which are in use but the major ones are mainly hydroprocessing catalysts, Fluid catalytic cracking catalysts and reforming catalysts. During processing, catalysts gets contaminated with impurities viz coke, sulfur, vanadium and nickel in the crude oil feed and becomes deactivated over a period of time. Diesel hydrodesulfurization catalysts typically have life cycle of 3-4 years where as FCC catalysts gets lost to atmosphere on daily basis and is offloaded fortnightly / monthly based on activity. Once catalysts completes their life cycle they will be withdrawn from the process, at this stage, catalysts are considered “spent” and the heavy metals, coke, and other poisonous elements make them as hazardous waste. As per literature Dufresne estimated that the total quantity of spent hydroprocessing catalysts generated worldwide is in the range of 150,000 to 170,000 tons per year. Therefore, with anticipated 5% annual increase in catalyst consumption, the generation of spent hydroprocessing catalysts predicted to be 200,000 tons annually. The exact figures of spent FCC catalysts are not available but considering the short life span of the catalyst and 400 FCC units operating across the world volumes assumed to be very high. Significant increase of spent hydroprocessing catalysts volumes are mainly attributed to rapid growth in the distillate hydrotreating capacity to meet the increasing demand for ultra low sulfur transportation fuels, reduced cycle times due to in increased severity operations to meet stringent fuel specifications and demand of processing sour crudes based on economic criteria.The traditional way of disposing the spent catalysts is land filling which is not environmentally friendly and occasisionally it leads to ground water contamination. Various options to reduce the generation of hazardous waste spent catalyst are using highly active catalysts, regeneration of the catalysts and reuse of the spent catalysts in other processes. The present paper will discuss about alternate ways of using spent catalyst by taking case study of hydroprocessing catalysts and thereby minimizing the waste spent catalyst in refining industry.

The state of nickel in spent Fluid Catalytic Cracking catalysts

The speciation of Ni in spent Fluid Catalytic Cracking catalysts is studied. Carefully performed XRD analyses with NiO/SiO2 samples used as calibration standards, demonstrate that the presence of NiO as a separate phase is reliably detected also for NiO concentration close to 0.1 wt% (1000ppmw). Actually, both on real spent FCC catalysts (ECAT's) and on artificially contaminated industrial FCC catalysts, NiO is not detectable as a separate phase, even after contamination of the order of 15,000ppmw of Ni. SEM–EDS experiments provide evidence of a largely preferential location of Ni on alumina particles present in the FCC catalyst mixture, thus acting as “nickel traps”. XRD, UV–vis and TPR data confirm that Ni deposits on alumina particles forming a hardly reducible surface and subsurface layer, giving rise to a solid whose composition is NixAl2O3+x with x<<0.25. As a result of this, the formation of extended Ni metal particles in the raiser reactor is avoided, being their unwanted dehydrogenation activity essentially eliminated. The absence of bulk NiO in the spent FCC catalysts (at least when Ni content is in the range 2000–10,000ppmw) allows the classification of this material as a non-hazardous waste.

Catalytic fast pyrolysis of straw biomass in an internally interconnected fluidized bed to produce aromatics and olefins: Effect of different catalysts

A novel reactor, named internally interconnected fluidized bed (IIFB), was specially designed for catalytic fast pyrolysis (CFP) of straw biomass. Catalytic characteristics of four types of catalysts (ZSM-5, LOSA-1, Gamma-Al2O3 and spent FCC catalysts) for producing aromatics and olefins were investigated in this reactor. The results show that IIFB reactor can realize CFP process. The maximum carbon yields of aromatics (12.8%) and C2-C4 olefins (10.5%) were obtained with ZSM-5. ZSM-5 shows the highest selectivity of naphthalene (12.1%), whereas spent FCC catalyst presents the highest selectivity of benzene (45.5%). The selectivity of ethylene and propylene are equal in the present of ZSM-5 and LOSA-1. Gamma-Al2O3 and spent FCC catalysts show a higher selectivity of ethylene than that of propylene. This paper provides a new reactor for CFP process and some suggestions for choosing catalyst.

Study of a Brazilian spent catalyst as cement aggregate by thermal and mechanical analysis

Fluidized catalytic cracking units of refineries normally use zeolite catalysts to treat heavy oil fractions. This catalyst is regenerated continuously, but due to the reduction of its activity during the process, it is partially substituted by a new catalyst make-up. The spent residue has a high content of silicon and aluminum oxides and usually presents pozzolanic properties. This paper presents the study of a Brazilian spent catalyst, which is being tested as a pozzolanic aggregate in partial substitution to cement. Pastes were prepared with 15, 20 and 25% in substitution to cement mass and analyzed after 28 days of hydration. Hydrated paste samples were analyzed by simultaneous thermogravimetry and differential thermal analysis, to quantify the calcium hydroxide consumption, as well as the content of other main hydrated cement phases. Compressive strength analysis was also performed after 28 days of hydration. Although, as spent catalyst content is increased, the pozzolanic activity is confirmed by the increase of calcium hydroxide consumption on cement mass basis, unlikely to other studied spent FCC catalysts, tested for the same purpose, the compressive strength of respective paste specimens decreases, due to the increase of other hydrated phases formation.

On the Nature of Nitrogen-Containing Carbonaceous Deposits on Coked Fluid Catalytic Cracking Catalysts

The regeneration of FCC catalysts leads to significant NOx emissions. Hence, the identification of surface deposits and reaction intermediates is important for understanding the mechanisms by which nitrogen-containing species are converted into NOx or N2. Characterization of the feed and of carbonaceous deposits on spent FCC catalysts by IR and NMR spectroscopy as well as by (MA)LDI-TOF mass spectrometry showed that polyaromatic pyrrole derivatives (alkylcarbazoles, alkylbenzocarbazoles, alkylindoles) are the main source of nitrogen in the feed of FCC units. Consequently, (poly-)aromatic compounds (m/z = 350−850) such as carbazole and quinoline derivatives are the main nitrogen-containing components in the coke. During oxidative regeneration, these pregraphitic species are converted into smaller aromatic compounds similar to the nitrogen molecules originally present in the feedstock. With increasing temperature, nitrogen-containing coke species accumulate on the catalyst surface and can only be removed by...

Encapsulation of heavy metals on spent fluid catalytic cracking catalyst

Vanadium and nickel were found as major contaminants on spent FCC catalyst at levels of 3518 ppm and 3225 ppm, respectively. XPS results indicated that vanadium and nickel were in oxide form on spent FCC catalysts. Leaching tests (TCLP) showed that vanadium from spent FCC catalysts poses an environmental problem if disposed by landfill. It was found that encapsulation treatment with up to 60 wt % spent FCC catalyst in Portland cement, is an effective means of stabilization. The strength of standard specimens containing catalyst was much lower than that of standard specimens made with same weight percentage of sand.

Encapsulation of heavy metals on spent fluid catalytic cracking catalyst

Vanadium and nickel were found as major contaminants on spent FCC catalyst at levels of 3518 ppm and 3225 ppm, respectively. XPS results indicated that vanadium and nickel were in oxide form on spent FCC catalysts. Leaching tests (TCLP) showed that vanadium from spent FCC catalysts poses an environmental problem if disposed by landfill. It was found that encapsulation treatment with up to 60 wt % spent FCC catalyst in Portland cement, is an effective means of stabilization. The strength of standard specimens containing catalyst was much lower than that of standard specimens made with same weight percentage of sand.