Search Results (115)

Aluminum polyoxocations were introduced into a lamellar zirconium phosphate (α-ZrP) via ion exchange. The Al polyoxocation pillars transformed into Al₂O₃ particles within the interlayer zone after calcination at 673 K. The resulting Al₂O₃-α-ZrP exhibited a large BET surface area and medium-strength acidity. Pt-supported Al₂O₃-α-ZrP was used as a catalyst for hydrocracking squalene and Botryococcus braunii oil in an autoclave batch system. In a one-step squalene hydrocracking process, the yield of jet-fuel-range hydrocarbons was 52.8% on 1 wt.% Pt/Al₂O₃-α-ZrP under 2 MPa H₂ at 623 K for 3 h. A two-step process was designed with the first step at 523 K for 1 h and the second at 623 K for 3 h. During the first step, the squalene was hydrogenated to squalane without cracking, and in the second step, the squalane was hydrocracked. This two-step catalytic process increased the yield of jet-fuel-range hydrocarbons to 65% in squalene hydrocracking. For algae oil hydrocracking, the jet-fuel-range hydrocarbons occupied 66% of the total products in the two-step reaction. Impurities in algae oil, mainly fatty acids, did not affect the yield of jet-fuel-range hydrocarbons because they were deoxygenated into hydrocarbons during the reaction. The activity of Pt/Al₂O₃-α-ZrP remained unchanged after four reuses through simple filtration. Full article

Zeolites are widely used as solid acid catalysts and also as supports in complex multifunctional heterogeneous systems. In recent years, there has been an increase in the development of zeolite-based catalysts with hierarchical porosity combined with metal dopants (modifiers or catalysts). These modifications can significantly improve the catalytic characteristics of such materials. In this review, we discuss the application of hierarchically porous zeolites, including metal-doped ones, in catalytic reactions employed in the production and upgrading of liquid fuels, i.e., pyrolysis of biomass and polymeric wastes; conversion of alcohols to fuel hydrocarbons, aromatics and olefins; cracking and hydrocracking of polymeric wastes and hydrocarbons; and hydroisomerization. It is revealed that, in many cases, higher activity, selectivity and stability can be achieved for metal-doped hierarchical zeolites in comparison with parent ones due to control over the diffusion, surface acidity and coke deposition processes. Full article

ZSM-5 zeolites are primarily used in acid-catalyzed hydrocracking reactions in the petrochemical industry, and it is very important to ensure an adequate number of acidic sites for more efficient catalytic activity. This study investigated the possibility of exchanging sodium ions with hydrogen ions on ZSM-5 zeolite with a molar ratio of (SiO₂/Al₂O₃ = 1000) using an ion-exchange process with acetic acid. By employing the XRD and FT-IR methods, along with chemical analysis of ZSM-5 zeolite samples, the influence of hydrogen ion concentration on the chemical composition and structural characteristics of ZSM-5 zeolite was monitored at different acid concentrations and exchange times. It was shown that ion exchange with acetic acid leads to a significant reduction in sodium content even with less concentrated solutions while maintaining the stability of the crystal structure of ZSM-5 (SiO₂/Al₂O₃ = 1000) and a high degree of crystallinity. Full article

Modern aviation is one of the main consumers of petroleum-based fuels, consuming nearly 100 million gallons of fuel per year, and this consumption continues to grow. On the other hand, airlines have committed to achieving net-zero carbon dioxide (CO₂) emissions in the industry by 2050. Fulfilling this commitment necessitates the investigation of new and the optimization of existing processes for the production of alternative, renewable, and environmentally safe feedstocks. This article was prepared as part of the research project “Development of Technological Solutions for Obtaining Composite Motor Fuels from Secondary Raw Materials to Enhance Energy Security”. Full article

The production of very-low-sulfur residual fuel oil is a great challenge for modern petroleum refining because of the instability issues caused by blending incompatible relatively high-sulfur residual oils and ultra-low-sulfur light distillates. Another obstacle in the production of very-low-sulfur residual fuel oil using hydroprocessing technology is the contradiction of hydrodesulfurization with hydrodemetallization, as well as the hydrodeasphaltization functions of the catalytic system used. Therefore, the production of very-low-sulfur residual fuel oil by employing hydroprocessing could be achieved by finding an appropriate residual oil to be hydroprocessed and optimal operating conditions and by controlling catalyst system condition management. In the current study, data on the characteristics of 120 samples of heavy fuel oils produced regularly over a period of 10 years from a high-complexity refinery utilizing H–oil vacuum residue hydrocrackers in its processing scheme, the crude oils refined during their production, the recipes of the heavy fuel oils, and the level of H–oil vacuum residue conversion have been analyzed by using intercriteria and regression analyses. Artificial neural network models were developed to predict the characteristics of hydrocracked vacuum residues, the main component for the production of heavy fuel oil. It was found that stable very-low-sulfur residual fuel oil can be manufactured from crude oils whose sulfur content is no higher than 0.9 wt.% by using ebullated bed hydrocracking technology. The diluents used to reduce residue viscosity were highly aromatic FCC gas oils, and the hydrodemetallization rate was higher than 93%. Full article

Fossil fuels remain essential to the world’s energy supply, but the decline in the quality of the oil extracted has increased the relevance of processes such as hydrocracking. Despite its potential, this process involves high energy consumption. In order to assess its efficiency, an exergy analysis of a conventional hydrocracking unit was carried out using Computer Aided Process Engineering (CAPE) tools. After simulations, the physical and chemical exergies of the input and output streams were calculated, which showed a remarkable energy efficiency of 98.76%, attributable to the high exergy content of the products obtained (171,243,917.70 MJ/h) compared to the residues generated (1,065,290.8 MJ/h). The most significant irreversibilities were found in the Recycle Gas Sweetening stage, while the lowest exergy efficiency, 87.16%, was observed in the Residual Gas Sweetening phase. By valorizing the waste, the overall efficiency of the process increased to 99.26%, which allowed for a 40% reduction in the total irreversibilities. Optimization of the stages with the highest unavoidable losses and better energy integration of the process are suggested to maximize its performance. Full article

The residue conversion processes, coking, visbreaking, and fluid catalytic cracking (FCC), have demonstrated that feedstock quality is the single factor that most affects process performance. While, for the FCC, it is known that the heavy oil conversion at a maximum gasoline yield point can vary between 50 and 85 wt. %, for the vacuum residue hydrocracking, no reports have appeared yet to reveal the dependence of conversion on the quality of vacuum residue being hydrocracked. In order to search for such a dependence, eight vacuum residues derived from medium, heavy, and extra heavy crude oils have been hydrocracked in a laboratory unit at different reaction temperatures. The current study has witnessed that the vacuum residue hydrocracking obeys the same rule as that of the other residue conversion processes, confirming that the feedstock quality has a great influence on the process performance. A conversion variation between 45 and 85 wt. % can be observed when the sediment content in the hydrocracked atmospheric residue is within the acceptable limit, guaranteeing the planned cycle length. An intercriteria analysis was performed, and it revealed that the vacuum residue conversion has negative consonances with the contents of nitrogen and metals. Correlations were developed which predict the conversion at constant operating conditions within the uncertainty of conversion measurement of 1.7 wt. % and correlation coefficient of 0.964. The conversion at constant hydrocracked atmospheric residue (HCAR) sediment content was predicted with a correlation coefficient of 0.985. The correlations developed in this work disclosed that the higher the contents of metals, nitrogen, and asphaltenes, and the lower the content of sulfur, the lower the conversion in the hydrocracking process is. It was also shown that vacuum residues, which have the same reactivity (the same conversion at identical operating conditions), can indicate significant difference in the conversion at the same HCAR sediment content due to their diverse propensity to form sediments in the process of hydrocracking. Full article

The efficient utilization of heavy oil is of great significance to alleviating the global energy crisis. How to efficiently convert heavy oil into high-value-added light fuel oil has become a hot issue in the field of petrochemicals. As the residual part of crude oil processing, heavy oil has a complex composition and contains polycyclic aromatic hydrocarbons, long-chain alkanes, and heteroatom compounds, which makes it difficult to process directly. Zeolite, as an important type of solid acid catalyst, has a unique pore structure, adjustable acidity, and good thermal stability. It can promote the efficient cracking and conversion of heavy oil molecules, reduce coke formation, and improve the yield and quality of light oil products. This paper systematically reviews the development status of heavy oil cracking technology, focusing on the structural characteristics, acidity regulation of zeolite catalysts, and their applications in heavy oil cracking and hydrocracking. The mechanism of the cracking reaction of polycyclic aromatic hydrocarbons and long-chain alkanes is analyzed in detail, and the catalytic characteristics and modification methods of zeolite in the reaction process are explained. In addition, this paper summarizes the main challenges faced by zeolite catalysts in practical applications, including uneven acidity distribution, limited pore diffusion, and easy catalyst deactivation, and proposes targeted development strategies. Finally, this paper looks forward to the future development direction of zeolite catalysts in the field of heavy oil cracking and upgrading reactions, emphasizes the importance of structural optimization and multi-scale characterization, and provides theoretical support and practical reference for the design and industrial application of efficient zeolite catalysts. Full article

The accurate prediction of hydrocracking product yields is crucial for optimizing resource allocation and improving production efficiency. However, the prediction of product flowrates in hydrocracking units often faces challenges due to insufficient data and weak correlations between input and output variables. This study proposes a hybrid framework combining a Convolutional Neural Network–Long Short-Term Memory (CNN-LSTM) model, mechanism modeling, and Particle Swarm Optimization (PSO) to address these issues. The CNN-LSTM captures spatiotemporal dependencies in operational data, while the mechanism model incorporates domain-specific physical constraints. The hybrid model is structured in both series and parallel configurations, with PSO optimizing key hyperparameters to enhance its predictive performance. The results demonstrate significant improvements in prediction accuracy, with determination coefficients (R²s) reaching 0.896 (kerosene), 0.879 (residue), 0.899 (heavy naphtha), and 0.78 (light naphtha). Shapley Additive Explanations (SHAP) and Mutual Information Coefficient (MIC) analyses highlight the mechanism model’s role in improving feature interpretability. This study underscores the efficacy of integrating kinetics modeling, deep learning, and metaheuristic optimization for complex industrial processes under data constraints, offering a robust approach to enhance hydrocracking yield prediction. Full article

Chemical recycling of plastic waste, especially polyolefins, into valuable liquid fuels is of considerable significance to address the serious issues raised by their threat on environmental and human health. Nevertheless, the construction of efficient and economically viable catalytic systems remains a significant hurdle. Herein, we developed an efficient bifunctional catalyst system comprising γ-Al₂O₃-supported ruthenium nanoparticles (Ru/γ-Al₂O₃) and β-zeolite for the conversion of polyolefins into gasoline-range hydrocarbons. A yield of C_5–12 paraffins up to 73.4% can be obtained with polyethene as the reactant at 250 °C in hydrogen. The Ru sites primarily activate the initial cleavage of C–H bonds of polymer towards the formation of olefin intermediates, which subsequently go through further cracking and isomerization over the acid sites in β-zeolite. Employing in situ infrared spectroscopy and probe–molecule model reactions, our investigation reveals that the optimized proportion and spatial distribution of the dual catalytic sites are pivotal in the tandem conversion process. This optimization synergistically regulates the cracking kinetics and accelerates intermediate transfer, thereby minimizing the production of side C_1–4 hydrocarbons resulting from over-cracking at the Ru sites and enhancing the yield of liquid fuels. This research contributes novel insights into catalyst design for the chemical upgrading of polyolefins into valuable chemicals, advancing the field of plastic waste recycling and sustainable chemical production. Full article

This article considers modern approaches to obtaining synthetic oil from unconventional hydrocarbon feedstocks, including plastic waste, tires, biomass, coal, and extra-heavy oil. Particular attention is paid to multi-stage technologies, such as pyrolysis, catalytic depolymerization, gasification followed by Fischer–Tropsch synthesis, and hydrocracking of heavy residues. The important role of catalysts in increasing the selectivity and economic efficiency of processes is noted: nanostructured, bifunctional, and pollution-resistant systems are increasingly used. Economic factors influencing the competitiveness of this industry are considered, including the volatility of prices for traditional oil, government support measures, and the development of waste logistics infrastructure. It is emphasized that the strengthening of the position of synthetic oil is associated with the growth of environmental requirements stimulating the recycling of plastics, tires, and biomass; at the same time, compliance with high environmental standards and transparency of emission control play a critical role in the social aspects of projects. In addition to improving the environmental situation, the development of synthetic oil contributes to the creation of jobs, the resolution of problems of shortage of classical oil fields, and the increase of energy security. It is concluded that further improvement of technologies and integration into industrial clusters can turn this sphere into a significant component of the future energy sector. Full article

Ebullated bed vacuum residue hydrocracking is a well-established technology providing a high conversion level of low-value residue fractions in high-value light fuels. The main challenge in this technology when processing vacuum residues derived from different crude oils is the sediment formation rate that leads to equipment fouling and cycle length shortening. With the severity enhancement, the asphaltenes become more aromatic and less soluble which leads to sediment formation when the difference between solubility parameters of asphaltenes and maltenes goes beyond a threshold value. Although theoretical models have been developed to predict asphaltene precipitation, the great diversity of oils makes it impossible to embrace the full complexity of oil chemistry by any theoretical model making it impractical for using it in all applications. The evaluation of process data of a commercial ebullated bed vacuum residue hydrocracker, properties of different feeds, and product streams by intercriteria and regression analyses enabled us to decipher the reason for hydrocracked oil sediment content rising from 0.06 to 1.15 wt.%. The ICrA identified the presence of statistically meaningful relations between the single variables, while the regression analysis revealed the combination of variables having a statistically meaningful effect on sediment formation rate. In this study, vacuum residues derived from 16 crude oils have been hydrocracked as blends, which also contain fluid catalytic cracking heavy cycle oil and slurry oil (SLO), in a commercial H-Oil plant. It was found that the hydrocracked oil sediment content decreased exponentially with fluid catalytic cracking slurry oil augmentation. It was also established that it increased with the magnification of resin and asphaltene and the reduction in sulfur contents in the H-Oil feed. Full article

The increasing requirement for distillates, accompanied by higher quantities of heavy crude oil in world production, has positioned gas oil hydrocracking as one of the most significant processes in refineries. In the petrochemical industry, hydrocracking is an essential process that converts heavy hydrocarbons into lighter and more valuable products such as LPG (liquefied petroleum gas), diesel, kerosene, light naphtha, and heavy naphtha. This method uses hydrogen and a catalyst to break down the gas oil feedstock through hydrogenation and hydrocracking reactions. However, the gas oil hydrocracking process faces significant technical, economic, and financial obstacles that must be overcome to reveal its full potential. In this study, a computer-assisted technical–economic evaluation and an evaluation of the technical–economic resilience of the gas oil hydrocracking process at an industrial scale was carried out. Twelve technical–economic and three financial indicators were evaluated to identify this type of process’s current commercial status and to analyze possible economic performance parameter optimizations. The economic indicators listed include gross profit (GP), profitability after taxes (PAT), economic potential (EP), cumulative cash flow (CCF), payback period (PBP), depreciable payback period (DPBP), return on investment (ROI), internal rate of return (IRR), net present value (NPV), annual cost/revenues (ACR), break-even point (BEP), and on-stream efficiency at the BEP. On the other hand, the financial indicators proposed by the methodology are earnings before taxes (EBT), earnings before interest and taxes (EBIT), and earnings before interest, taxes, depreciation, and amortization (EBITDA). The technical–economic resilience of the process was also evaluated, considering the costs of raw materials, the market prices of the products, and processing capacity. The gas oil hydrocracking plant described, with a useful life of 20 years and a processing capacity of 1,937,247.91 tonnes per year, achieved a gross profit (GP) of USD 58.97 million and a return after tax (PAT) of USD 39.77 million for the first year, operating at maximum capacity. The results indicated that the process is attractive under a commercial approach, presenting a net present value (NPV) of USD 68.87 million at the end of the last year of operation and a cumulative cash flow (CCF) of less than one year⁻¹ (0.34 years⁻¹) for the first year at full processing capacity, which shows that in this process, variable costs have more weight on the economic indicators than fixed costs. Full article

Soluble organics (SBC-L) from Santanghu bituminous coal (SBC) were obtained by extracting the coal with a mixed solvent of CS₂ and acetone (v/v′ = 1:1). Catalytic hydrogenation of SBC-L was carried out using isopropanol as the solvent and prepared bimetallic material (Ni-Mo/γ-Al₂O₃) as the catalyst, and the hydrogenation product (SBC-L_IP320) was obtained. Gas chromatography-mass spectrometry (GC-MS) was used to compare the difference in the composition and distribution of SBC-L and SBC-L_IP320; thus, the effect of the used catalyst on the hydrogenation performance and heteroatom removal of SBC-L can be investigated. Results showed that the organic compounds in SBC-L and SBC-L_IP320 could be classified into aliphatic hydrocarbons (AHS), arenes, oxygen-containing organic compounds (OCOCs), nitrogen-containing organics (NCOCs), and compounds containing other heteroatoms (OHACOCs). The relative contents of AHS and arenes detected in SBC-L_IP320 were higher than those of SBC-L, while the contents of OCOCs, NCOCs, and OHACOCs decreased, and no S-containing compounds could be detected in SBC-L_IP320. It can be concluded that the prepared catalyst presents good de-oxygenation, de-sulfurization, de-nitrogenation, and hydrocracking performance. Full article

In this paper, we discuss options for the synthesis of granular free-binder ZSM-5 zeolites using synthetic aluminosilicates prepared by sol-gel technology with organic and inorganic silicon sources. It has been shown that the properties of the amorphous aluminosilicate used to prepare the initial granules influence the crystallization conditions, as well as the morphology and size of the crystals formed from granular ZSM-5 zeolite. The granular free-binder Pt/ZSM-5 with a developed secondary porous structure showed higher activity in the hydrocracking of hexadecane than the granular binder Pt/ZSM-5. At a reaction temperature of 220 °C, the conversion of n-hexadecane in the granular free-binder sample was 59.1%. At the same time, the selectivity for hexadecane isomers was 15.7%. Full article