Fluid Catalytic Cracking Slurry Research Articles

Flower-like CoSe2/N, P-doped carbon microspheres accommodated on carbon nanosheets for high-performance potassium-ion batteries

Transition metal selenides (TMSs) have emerged as promising electrode materials for potassium-ion batteries (PIBs), whereas the large volume expansion and sluggish reaction kinetics have seriously hindered the cycle life and rate performance. Herein, a hierarchical composite of flower-like CoSe2/N, P-doped carbon microspheres accommodated on carbon nanosheets (CoSe2-NPC@CNS) was rationally fabricated as the anode for PIBs through a one-pot hydrothermal and subsequent selenization method. The intimate hybridization of CoSe2/N, P-doped carbon microspheres can effectively alleviate the volume expansion of CoSe2 during charge-discharge cycles, and the ultrathin carbon nanosheets derived from fluid catalytic cracking (FCC) slurry serves as a highly conductive and buffered substrate. By robustly merging them together, the interconnected hierarchical nanoarchitecture with exposed active sites achieves promoted potassium storage capacity, electrochemical reaction kinetics, and structural stability. As a result, the PIBs with CoSe2-NPC@CNS anode deliver high reversible capacities of 320.8 mAh g−1 after 100 cycles at 0.1 A g−1 and 213.9 mAh g−1 after 850 cycles at 1.0 A g−1, excellent rate capability (188.8 mAh g−1 at 5 A g−1), and enhanced pseudo-capacitive contribution rate of 88.7 %. This work offers valuable insight into the rational design and development of hierarchical anode materials with high performance for PIBs and beyond.

The Neglected Role of Asphaltene in the Synthesis of Mesophase Pitch.

This study investigates the synthesis of mesophase pitch using low-cost fluid catalytic cracking (FCC) slurry and waste fluid asphaltene (WFA) as raw materials through the co-carbonization method. The resulting mesophase pitch product and its formation mechanism were thoroughly analyzed. Various characterization techniques, including polarizing microscopy, softening point measurement, Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA), were employed to characterize and analyze the properties and structure of the mesophase pitch. The experimental results demonstrate that the optimal optical texture of the mesophase product is achieved under specific reaction conditions, including a temperature of 420 °C, pressure of 1 MPa, reaction time of 6 h, and the addition of 2% asphaltene. It was observed that a small amount of asphaltene contributes to the formation of mesophase pitch spheres, facilitating the development of the mesophase. However, excessive content of asphaltene may cover the surface of the mesophase spheres, impeding the contact between them and consequently compromising the optical texture of the mesophase pitch product. Furthermore, the inclusion of asphaltene promotes polymerization reactions in the system, leading to an increase in the average molecular weight of the mesophase pitch. Notably, when the amount of asphaltene added is 2%, the mesophase pitch demonstrates the lowest ID/IG value, indicating superior molecular orientation and larger graphite-like microcrystals. Additionally, researchers found that at this asphaltene concentration, the mesophase pitch exhibits the highest degree of order, as evidenced by the maximum diffraction angle (2θ) and stacking height (Lc) values, and the minimum d002 value. Moreover, the addition of asphaltene enhances the yield and aromaticity of the mesophase pitch and significantly improves the thermal stability of the resulting product.

Influence of two asphaltenes on the formation and development of mesophase in fluid catalytic cracking (FCC) slurry oil

Asphaltene constitutes the heaviest component in fluid catalytic cracking (FCC) slurry oil. Mesophase pitch are prepared from FCC slurry oil by adding two asphaltenes (CL-As/JB-As) with distinct structure, and the influence of asphaltenes on the formation of mesophase is investigated. The findings suggest that an addition of CL-As within the range of 0–20 wt% is advantageous for the development and formation of mesophase. The addition of JB-As less than 1 wt% facilitates the formation and development of mesophase, while the opposite is observed with JB-As greater than 1 wt%. This is due to the light fraction of JB-As (JB-As-L), which is similar to CL-As and possesses appropriate concentrations of reactive sites that promote the formation of mesophase. However, the prevalence of alkane-branched chains is most densely concentrated in the heavy fraction of JB-As (JB-As-H), which leads to an excessive concentration of reactive sites. The predominance of JB-As-H causes an increase of the system's viscosity in the early stage so that the collision of polycyclic aromatic hydrocarbon macromolecules is reduced and the formation of the mesophase is postponed eventually. This provides a profound understanding of the preparation of high-quality mesophase pitch by regulating the properties of raw materials.

Molecular structure regulation of FCCs enabling N/S co-doped hollow amorphous carbon with enlarged interlayer spacing and rich defects for superior potassium storage

Constructing high-performance and low-cost carbon anodes for potassium-ion batteries (PIBs) is highly desirable but faces great challenges. In this study, we present a novel approach to fabricating N/S co-doped hollow amorphous carbon (LNSHAC) for superior potassium storage through a template-assisted molecular structure regulation strategy. By tailoring a 3D crosslinked aromatics precursor from fluid catalytic cracking slurry (FCCs), the LNSHAC features a N/S co-doped hollow structure with enlarged interlayer spacing of up to 0.405 nm and rich defects. Such unique microstructure offers fast transport channels for K-ion intercalation/deintercalation and provides more active sites, leading to boosted reaction kinetics and potassium storage capacity. Consequently, the LNSHAC electrode delivers an impressive reversible capacity (466.2 mAh g−1 at 0.1 A/g), excellent rate capability (336.3 mAh g−1 at 2 A/g), and superior cyclic performance (256.9 mAh g−1 after 5000 cycles at 5 A/g with admirable retention of 76.9 %), standing out among the reported carbon-based anodes. When KFeHCF is employed as the cathode, the LNSHAC-based K-ion full cell exhibits a high reversible capacity of 176.6 mAh g−1 at 0.1 A/g and excellent cyclic stability over 200 cycles. This work will inspire the development and application of advanced carbon-based materials for potassium electrochemical energy storage.

Electronic synergy between CoP/NiCoP heterostructure and Co, Ni single atoms for efficient hydrogen evolution and overall water splitting

Transition metal phosphides (TMPs) are considered as potential electrocatalysts for hydrogen evolution (HER) and overall water splitting (OWS), but their excessively strong adsorption property toward H* limits the reaction kinetics. Herein, we design a bifunctional electrocatalyst (CoP/NiCoP/Co–Ni–N–C) supported by CoP/NiCoP heterostructure and Co, Ni single atoms, which was prepared via facile one-pot pyrolysis process. The interfacial electronic synergy between the high-electropositive Co–N–C, Ni–N–C and the electron-rich CoP/NiCoP heterostructure balanced the hydrogen binding strength, resulting in fast kinetics and high intrinsic activity. Besides, the g-C3N4 was applied as a self-sacrificial template to construct the N doped hierarchical porous carbon carrier, which provided abundant mass transfer pathways and enhanced the charge transfer efficiency. Additionally, the fluid catalytic cracking (FCC) slurry was intelligently applied as extra carbon source, which not only limited the size of CoP/NiCoP nanoparticles, but also increased the loading of Co and Ni single atoms. Benefit from those advantages, the optimized CoP/NiCoP/Co–Ni–N–C exhibited low overpotentials of 40 mV at 10 mA cm−2 toward HER in 1 M KOH. Meanwhile, the two-electrode system only need 1.54 V to achieve the current density of 10 mA cm−2. This work provided a kind of potential electrocatalyst for efficient water splitting and a method for low-cost catalyst design.

Influence of filler characteristics on particle removal in fluid catalytic cracking slurry under an alternating electric field

The characteristics of the packing material under an alternating electric field are an important factor in the removal of FCCS particles. In this study, the electric field distribution of a separation unit consisting of packed spheres under an alternating electric field is simulated, and the movement mechanism of catalyst particles is analysed. An "effective contact point" model is derived to predict the adsorption of filler contact points on catalyst particles under the alternating electric field, and the model is validated by simulations and experiments. The numerical calculation and experimental results indicate that the electrical properties of the filler spheres, the filler angle θ, and the frequency f of the alternating electric field affect the adsorption of catalyst particles. As the frequency of the electric field increases, the particle removal efficiency of the high-conductivity filler (silicon carbide) increases and then settles, and the separation efficiency of the low-conductivity filler (glass, zirconia) is not sensitive to the change in electric field frequency.

Removal of catalyst particles in the fluid catalytic cracking slurry oil by chemical settling in a rotating packed bed

Removal of catalyst particles from the fluid catalytic cracking (FCC) slurry oil is of crucial significance for its efficient utilization. In this work, the removal of catalyst particles from FCC slurry oil was performed in a stirring tank reactor (STR) and the optimal operating conditions in STR were obtained. Under the optimal operating conditions (900 rpm, 30 min, 95 °C, 24 h, 500 μg/g settling agent), the ash content in the FCC slurry oil treated by the chemical settling can be reduced from 5620 μg/g to 320 μg/g. These results showed that stirring speed, dosage of the settling agent, and mixing time are important to improve the removal efficiency of catalyst particles. Moreover, a rotating packed bed (RPB), as an intensified micromixing device, was employed to intensify the removal of catalyst particles from FCC slurry oil. The ash content in the FCC slurry oil treated by the chemical settling can be reduced from 5620 μg/g to 270 μg/g in RPB under the optimal operating conditions. The removal efficiency of the ash in RPB was increased by 15.6 % with respect to those obtained in STR. This work could provide relevant guidelines to rationally design efficient route for the removal of catalyst particles from FCC slurry oil.

Industrial Investigation of the Combined Action of Vacuum Residue Hydrocracking and Vacuum Gas Oil Catalytic Cracking While Processing Different Feeds and Operating under Distinct Conditions

Ebullated bed vacuum residue hydrocracking and fluid catalytic cracking (FCC) are among the most profitable processes in modern refining. Their optimal performance is vital for petroleum refining profitability. That is why a better understanding of their combined action and the interrelations between these two heavy oil conversion processes in a real-world refinery could provide valuable information for further performance optimization. Nine distinct petroleum crudes belonging to the extra light, light, and medium petroleum crude types were processed in the LUKOIL Neftohim Burgas refinery to study the combined performance of two processes: FCC of vacuum gas oil and ebullated bed vacuum residue H-Oil hydrocracking. The operating conditions along with the characterization data of the feeds and products of both processes were evaluated through the employment of intercriteria analysis to define the variables with statistically significant relationships. Maple 2023 Academic Edition mathematics software was used to develop models to predict the vacuum residue conversion level under different operating conditions. The plug flow reactor model with an activation energy of 215 kJ/mol and a reaction order of 1.59 was found to provide the highest accuracy of vacuum residue conversion, with an average absolute deviation of 2.2%. H-Oil yields were found to correlate with the vacuum residue conversion level and the content of FCC slurry oil (SLO), the recycling of partially blended fuel oil, a material boiling point below 360 °C, and the vacuum gas oil (VGO) in the H-Oil feed. FCC conversion was found to depend on the H-Oil VGO content in the FCC feed and the content of FCC SLO in the H-Oil feed.

Influence of resin on the formation and development of mesophase in fluid catalytic cracking (FCC) slurry oil

Resin is one of the key components of fluid catalytic cracking slurry oil which is the raw material to form high-quality mesophase pitch. The effect of resin variations on the formation of mesophase was investigated in this paper. The results showed when the resin addition was from 0 to 20 wt%, the formation rate of mesophase remained basically invariable, but it was beneficial to the development of mesophase pitch with higher order degree. However, excessive additions of resin (>20 wt%) sharply accelerated the formation of mesophase due to the high concentration of reactive sites in the system, which shortened the time to form pitch with mesophase content close to 100%, adversely it led to the generation of mesophase pitch with lower order degree. In addition, the approximate molecular structure model of resin was constructed by various characterization methods. The aromatic ring skeleton of resin was dominated by 3–4 ring aromatic hydrocarbons. Resin also possessed structural features such as higher aromaticity, higher N and S content, larger molecular size, longer branched chains, more cyclic alkane structures and methylene bridges, and higher concentration of reactive sites than FCC-exR. Furthermore, an explanation of the effect of resin on the formation and development of mesophase with respect to the molecular structure characteristics was presumed. This work has important implications for regulating the raw material properties of FCC slurry oil and the preparation of high-quality mesophase pitch.

Research progress in the preparation of mesophase pitch from fluid catalytic cracking slurry.

For the preparation of high-performance pitch-based carbon fibers and other carbon materials, mesophase pitch serves as a high-quality precursor. Since FCC (Fluid Catalytic Cracking) oil slurry is abundant in aromatic hydrocarbons and saturated hydrocarbons (about 95% in total), it has become an ideal choice for developing new carbon material products. This paper details the research progress of preparing mesophase asphalt with FCC oil slurry as a raw material from perspectives including the preparation method of synthesizing mesophase asphalt from FCC oil slurry, the impact factors of the formation process of mesophase asphalt and the industrial application of mesophase asphalt.

Effects of the properties of FCCS on the removing of catalyst particles from FCCS under a DC electrostatic field

Catalytic cracking is the main method to lighten heavy crude oil, this process can produce high quality oil products such as gasoline and diesel, but also produces a large amount of fluid catalytic cracking slurry (FCCS). The catalyst particles in FCCS seriously restrict the secondary processing of FCCS and need to be removed, and the properties of FCCS is an important factor that affects the removal efficiency of the catalyst particles. Based on the “effective contact point” model proposed by the research group, this study further proposed the “electrostatic separation efficiency calculation” model. In this model, since FCCS has a uniform distribution of catalyst particles, the ratio of the number of catalyst particles can be expressed as the ratio of area to achieve the calculation of separation efficiency. Then the catalyst removal efficiency under different viscosity was analyzed, thus verifying the feasibility of this model. The effects of temperature and mass ratio of four components on the viscosity of FCCS were investigated respectively, then the effects of temperature and four components’ mass ratio on the electrostatic separation can be directly converted into the effect of viscosity on the electrostatic separation efficiency. All the results show the electrostatic separation efficiency decreases with increasing viscosity, and the best separation temperature is 120 °C.

Interfacial Electronic Engineering of NiSe–Anchored Ni–N–C Composite Electrocatalyst for Efficient Hydrogen Evolution

Rational design and construction of cost–effective electrocatalysts for efficient hydrogen production has attracted extensive research attention worldwide. Herein, we report the construction of a transition metal selenide/carbon composite catalyst featuring uniform NiSe nanoparticles anchored to single Ni atom doped porous carbon structure (NiSe/Ni–N–C) via a facile one–pot pyrolysis of low–cost solid mixtures. NiSe/Ni–N–C exhibits remarkable catalytic performance towards hydrogen evolution reaction (HER) in 1.0 M KOH, requiring a low overpotential of 146 mV to reach a current density of 10 mA cm−2. The unique carbon layer encapsulation derived from the enwrapping of fluid catalytic cracking slurry further renders NiSe/Ni–N–C excellent for long–term durability in electrolyte corrosion and nanostructure aggregation. This work paves the way for the design and synthesis of highly efficient composite HER electrocatalysts.

Promotion of boron phosphate on the NiMoAl catalyst for hydroprocessing FCC slurry oil

Mesoporous NiMoAl catalysts with boron phosphate (BPO4) modification were synthesized through the complete liquid-phase method. X-ray diffraction (XRD) analysis evidenced the presence of BPO4-AlOOH mixed support in these BPO4-modified NiMoAl samples. The total amount of acid sites declined, but the surface acidity was strengthened by adding BPO4 into the NiMoAl catalyst. It's worth noting that the incorporation of BPO4 could increase the concentrations of Ni and Mo species on the catalyst surface and greatly improve the dispersion of (Ni)MoS2 active phases, as indicated by X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) measurements. The catalytic performance of these BPO4-modified NiMoAl catalysts was investigated with the hydroprocessing of fluid catalytic cracking (FCC) slurry oil. The nitrogen-containing compounds removal from the oil was significantly enhanced with increasing the molar ratio of boron phosphate/aluminum. The NM-BPA(0.55) catalyst exhibited the best hydrodenitrogenation (HDN) activity, highlighting the significant impact of Mo sulfidation degree and the dispersion of active metals on HDN performance. The introduction of boron phosphate could also promote the hydrocracking activity of the NiMoAl catalyst, as demonstrated by SARA analysis and simulated distillation of liquid products.

Purification of fluid catalytic cracking slurry oil at room temperature using ceramic membrane

The catalyst particles were removed from fluid catalytic cracking (FCC) slurry oil by two-step separation processing. FCC slurry oil was mixed with water and surfactant to make the lower viscosity emulsion. The catalyst particles were removed from the emulsion using the modified hydrophobic ceramic membrane (0.1 μm) and then the water was filtered out from oil/water emulsion using an unmodified hydrophilic ceramic membrane (0.05 μm) at room temperature. The separation efficiency of catalyst particles and emulsion reached 99.9% and the oil/water separation efficiency also reached 99.9%. FCC slurry oil was effectively purified at room temperature by a two-step treatment.

Modification of FCC slurry oil and deoiled asphalt for making high-grade paving asphalt

With the rapid development of modern industry, high-grade paving asphalt is massively required to meet the demands for modern transportation. As one of additives, natural asphalt is indispensable since it can improve the performance of paving asphalt in all aspects. However, the application of non-renewable natural asphalt is increasingly restricted by its limited reserves. It is imperative to find alternative approaches to produce high-grade paving asphalt. Fluid catalytic cracking (FCC) slurry oil is an ideal soft component for producing paving asphalt due to its high content of aromatics and resins. However, its bad ageing resistance limits its application to only low-grade paving asphalt. In the present work, a novel approach for producing high-grade paving asphalt was investigated using chemically modified FCC slurry oil and deoiled asphalt (DOA). The FT-IR and NMR results showed that dehydrogenation and condensation reaction occurred during the ageing process. From a series of aliphatic alcohols and aldehydes, propanal was selected as a proper modifier to improve the ageing resistance of FCC slurry oil. The propanal-modified slurry oil possessed more substituted aromatic units and less aromatic hydrogen atoms than other modified slurry oils, thus showing better ageing resistance. With the increase of length of aliphatic chains in modifier, the modified slurry oil contained more and longer alkyl substituent group on aromatics. Compared with the cross-linked oil (slurry oil modified by cross-linking agent), modified slurry oil possessed similar ageing resistance but higher flowing ability. Also, the effect of operation conditions on the kinematic viscosity of modified slurry oil were investigated. Blended with modified slurry oil, the penetration ratio of asphalt product increased from 53.7 to 66.2, which met the standard of 70# paving asphalt. Both the microscopic observations and FT-IR results indicated that modification process effectively reduced the oxidation degree of asphalt product, thus increasing the ageing resistance. Consequently, with aid of this process, high-grade paving asphalt was readily produced from low value oil from downstream products of refinery, instead of the depleting natural asphalt.

Influence of Resin Variations on the Formation and Development of Mesophase in Fluid Catalytic Cracking (Fcc) Slurry Oil

Influence of Resin Variations on the Formation and Development of Mesophase in Fluid Catalytic Cracking (Fcc) Slurry Oil

Effect of stacking method of fillers on the electrostatic separation performance of FCC slurry

The stacking method of the fillers is an important factor that affects the removal efficiency of the catalyst particles in the fluid catalytic cracking slurry (FCCS). This study proposed the parameter η, which can characterize the adsorption capacity of the separation unit. The variation of η of the separation unit under different arrangement angles were investigated by numerical simulation and theoretical calculation respectively, thus verifying the feasibility of η. In addition, the separation efficiency of four different stacking methods was studied by numerical simulation and experiment research. The research results showed that η was related to the angle between the fillers and the direction of the electric field and the space utilization of the separation unit, and the adsorption capacity of fcc and hcp stacking models were the same and best. This research could be used to judge the separation efficiency of electrostatic separators with different stacking methods of fillers.

Highly Efficient Water Splitting Catalyst Composed of N,P-Doped Porous Carbon Decorated with Surface P-Enriched Ni2P Nanoparticles.

A non-noble-metal hybrid catalyst (Ni2P/NPC-P), composed of N,P-doped porous carbon decorated with surface P-enriched Ni2P nanoparticles, is developed to address the urgent challenges associated with mass production of clean hydrogen fuel. The synthesis features one-pot pyrolysis of inexpensive fluid catalytic cracking slurry, graphitic carbon nitride, and inorganic salts, followed by a feasible surface phosphidation process. As a non-noble metal catalyst, Ni2P/NPC-P demonstrates excellent performance in hydrogen evolution reaction in alkaline electrolytes with a low overpotential of 73 mV at a current density of 10 mA cm-2 (η10) and a small Tafel slope of 56 mV dec-1, meanwhile exhibits durability with no significant η10 change after 2000 catalytic cycles. Theoretical calculation reveals that the negatively charged P-enriched surface accelerated the rate-determining transformation and desorption of OH*. In overall water splitting, the electrocatalyst achieves a low η10 of 1.633 V, promising its potential in the cost-effective mass production of hydrogen fuel.

Comparison of Empirical Models to Predict Viscosity of Secondary Vacuum Gas Oils

This work presents characterization data and viscosity of 34 secondary vacuum gas oils (H-Oil gas oils, visbreaker gas oils, and fluid catalytic cracking slurry oils) with aromatic content reaching up to 100 wt.%. Inter-criteria analysis was employed to define the secondary VGO characteristic parameters which have an effect on viscosity. Seven published empirical models to predict viscosity of the secondary vacuum gas oils were examined for their prediction ability. The empirical model of Aboul-Seud and Moharam was found to have the lowest error of prediction. A modification of Aboul-Seoud and Moharam model by separating the power terms accounting for the effects of specific gravity and average boiling point improves the accuracy of viscosity prediction. It was discovered that the relation of slope of viscosity decrease with temperature enhancement for the secondary vacuum gas oil is not a constant. This slope increases with the average boiling point and the specific gravity augmentation, a fact that has not been discussed before.

Molecular engineering and modification of FCC slurry oil residue for improving ageing resistance of high quality paving asphalt

In the present work, a novel resin molecule based on fluid catalytic cracking (FCC) slurry oil residue was designed and prepared with aid of molecular simulation to improve its ageing resistance. The average molecular structure of resin was characterized with elemental analysis, Fourier-transform IR (FT-IR) spectroscopy, NMR spectroscopy and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) and designed resin was synthesized by attaching an additional propyl group to the as-received resin. The interactions of resins and asphaltene molecules were investigated via molecular simulation, UV-visible (UV-Vis) spectroscopy and atomic force microscopy (AFM). The results revealed that the equilibrium distance of designed resin-asphaltene dimer decreased from 0.42 nm to 0.38 nm while the lowest contact energy increased from 9.3 kcal/mol to 11.2 kcal/mol, indicating an improved stability of designed resin-asphaltene particles. The adsorption isotherm indicated that more modified resin molecules could be adsorbed by asphaltene than the original resin. Compared with original asphalt, less aggregation of asphaltene occurred in asphalt blended with modified slurry oil residue during ageing process, showing its greatly improved ageing resistance.