Search Results (162)

Biorefineries offer a sustainable approach to producing fuels, chemicals, food, and feed from biomass, presenting a viable strategy for mitigating greenhouse gas (GHG) emissions and reducing reliance on fossil fuels. This review provides a comprehensive overview of the biorefinery concept, with a particular focus on its integrated conversion processes, classification pathways, and the potential for retrofitting existing fossil fuel refineries. Emphasis is placed on the Gulf Cooperation Council (GCC) region, home to some of the world’s largest hydrocarbon processing infrastructures, as a strategic case study for deploying biorefinery technologies. This review presents the latest trends in integrated biorefinery configurations and the potential for upgrading to drop-in fuels. It examines conventional biorefineries in the GCC, outlines their processing capacities, and explores suitable biomass feedstocks that thrive under the region’s high-temperature and high-salinity conditions. By highlighting both technological advancements and regional opportunities, this study underscores the potential for leveraging existing infrastructure in oil-rich nations to facilitate the transition toward sustainable bioenergy systems. Full article

As attention to environmental risks from the PAHs in biochar production increases, developing a low-cost and easy-to-operate optimized pyrolysis process is urgent. The effect of extra biochar was investigated in order to minimize polycyclic aromatic hydrocarbons (PAHs) on biochar and residual tar for the development of a new fixed-bed pyrolysis process. Hence, the effect of extra biochar as a catalyst on the reduction effect on PAHs originating from corn stover pyrolysis was inspected and explored in this study. Pyrolysis was conducted at 500, 600, and 700 °C in a tube furnace reactor with corn stover as the biomass feedstock. Biochar prepared at 500 °C, 600 °C, and 700 °C was used as a catalyst by stacking extra biochar on top of the corn stover raw material. Then, the concentration of PAHs in corn stover biochar and residual tar inside the reactor was examined. The physicochemical characteristics, including morphology, pore structure, and chemical structures of extra biochar, were investigated separately. The results showed that, with stacking extra biochar, the concentrations of PAHs in corn stover biochar (7.15 mg/kg to 1.25 mg/kg) and residual tar (132.23 mg/kg to 101.10 mg/kg) inside the reactor decreased significantly at medium temperatures (500 °C). The concentrations of PAHs in corn stover biochar decreased from 9.14 mg/kg, 10.44 mg/kg to 3.66 mg/kg, 2.7 mg/kg. However, the concentrations of PAHs of residual tar inside the reactor increased significantly at medium temperatures (600 °C, 700 °C). In addition, the reaction mechanism of extra biochar as a catalyst to reduce PAHs in corn stover biochar was established. The results suggest that the measure of adding extra biochar reduced PAHs in resulting biochar effectively, but is not high enough to eliminate PAHs issues in the entire pyrolysis process completely. Full article

The Allam power cycle is a groundbreaking elevated-pressure power generation unit that utilizes oxygen and fossil fuels to generate low-cost electricity while capturing carbon dioxide (CO₂) inherently. In this project, we utilize the CO₂ generated from the Allam cycle as feedstock for a newly envisioned industrial complex dedicated to producing renewable hydrocarbons. The industrial complex (FAAR) comprises four subsystems: (i) a Fischer–Tropsch synthesis plant (FTSP), (ii) an alkaline water electrolysis plant (AWEP), (iii) an Allam power cycle plant (APCP), and (iv) a reverse water-gas shift plant (RWGSP). Through effective material, heat, and power integration, the FAAR complex, utilizing 57.1% renewable energy for its electricity needs, can poly-generate sustainable hydrocarbons (C₁–C₃₀), pure hydrogen, and oxygen with near-zero emissions from natural gas and water. Economic analysis indicates strong financial performance of the development, with an internal rate of return (IRR) of 18%, a discounted payback period of 8.7 years, and a profitability index of 2.39. The complex has been validated through rigorous modeling and simulation using Aspen Plus version 14, including sensitivity analysis. Full article

Understanding the formation mechanisms of three-phase products during biomass pyrolysis is essential for optimizing thermochemical conversion and enhancing the efficient utilization of renewable resources. In this study, wheat straw (WS) and pine sawdust (PS) were selected as representative feedstocks to investigate the thermal decomposition behavior and evolution characteristics of gas, liquid (tar), and solid (char) products during pyrolysis. Thermogravimetric analysis and kinetic modeling revealed that PS exhibited higher activation energy (75.44 kJ/mol) than WS (65.63 kJ/mol), indicating greater thermal resistance. Tar yield increased initially and then declined with temperature, peaking at 700 °C (37.79% for PS and 32.82% for WS), while the composition shifted from oxygenated compounds to polycyclic aromatic hydrocarbons as temperature rose. FTIR analysis demonstrated that most functional group transformations in char occurred below 400 °C, with aromatic structures forming above 300 °C and stabilizing beyond 700 °C. Gas product evolution showed that WS produced higher CO and H₂ yields due to its composition, with CH₄ generated in relatively lower amounts. These findings provide insights into biomass pyrolysis mechanisms and offer a theoretical basis for targeted regulation of product distributions in bioenergy applications. Full article

Dry reforming of methane and ethanol is a promising catalytic process for the conversion of carbon dioxide and hydrocarbon feedstocks into synthesis gas (H₂/CO), which serves as a key platform for the production of fuels and chemicals. Over the past decade, substantial progress has been achieved in the design of catalysts with enhanced activity and stability under the demanding conditions of these strongly endothermic reactions. This review summarizes the latest developments in catalyst systems for DRM and EDR, including Ni-based catalysts, perovskite-type oxides, MOF-derived materials, and high-entropy alloys. Particular attention is given to strategies for suppressing carbon deposition and preventing metal sintering, such as oxygen vacancy engineering in oxide supports, rare earth and transition metal doping, strong metal–support interactions, and morphological control via core–shell and mesoporous architectures. These approaches have been shown to improve coke resistance, maintain metal dispersion, and extend catalyst lifetimes. The review also highlights emerging concepts such as multifunctional hybrid systems and innovative synthesis methods. By consolidating recent findings, this work provides a comprehensive overview of current progress and future perspectives in catalyst development for DRM and EDR, offering valuable guidelines for the rational design of advanced catalytic materials. Full article

Catalytic upgrading of pyrolysis oils is an important step for producing replacement hydrocarbon-rich liquid biofuels from biomass and can help to advance pyrolysis technology. Catalysts play a pivotal role in influencing the selectivity of chemical reactions leading to the formation of main compounds in the final upgraded liquid products. The present work involved a systematic study of solvent-free catalytic reactions of cyclohexanone in the presence of hydrogen gas at 160 °C for 3 h in a batch reactor. Cyclohexanone can be produced from biomass through the selective hydrogenation of lignin-derived phenolics. Three types of catalysts comprising undoped NbOPO₄, 10 wt% NiO/NbOPO₄, and 30 wt% NiO/NbOPO₄ were studied. Undoped NbOPO₄ promoted both aldol condensation and the dehydration of cyclohexanol, producing fused ring aromatic hydrocarbons and hard char. With 30 wt% NiO/NbOPO₄, extensive competitive hydrogenation of cyclohexanone to cyclohexanol was observed, along with the formation of C₆ cyclic hydrocarbons. When compared to NbOPO₄ and 30 wt% NiO/NbOPO₄, the use of 10 wt% NiO/NbOPO₄ produced superior selectivity towards bi-cycloalkanones (i.e., C₁₂) at cyclohexanone conversion of 66.8 ± 1.82%. Overall, the 10 wt% NiO/NbOPO₄ catalyst exhibited the best performance towards the production of precursor compounds that can be further hydrodeoxygenated into energy-dense aviation fuel hydrocarbons. Hence, the presence and loading of NiO was able to tune the activity and selectivity of NbOPO₄, thereby influencing the final products obtained from the same cyclohexanone feedstock. This study underscores the potential of lignin-derived pyrolysis oils as important renewable feedstocks for producing replacement hydrocarbon solvents or feedstocks and high-density sustainable liquid hydrocarbon fuels via sequential and selective catalytic upgrading. Full article

One of the most important challenges the tire industry faces is becoming carbon-neutral and using 100% sustainable materials by 2050. Utilizing materials from renewable sources and recycled substances is a key aspect of achieving this goal. Petroleum-based oils, such as Treated Distillate Aromatic Extract (TDAE), are frequently used in rubber compounds, and a promising strategy to enhance sustainability is to use bio-based plasticizer alternatives. However, research has shown that the replacement of TDAE oil with bio-based oils or resins can significantly alter the glass transition temperature (T_g) of the final compound, influencing the tire properties. In this study, the theory was proposed that using a plasticizer blend, comprising oil and resin, in a rubber compound would result in similar T_g values as the reference compound containing TDAE. To test this, the cycloaliphatic di-ester oil Hexamoll DINCH, which can be made out of bio-based feedstock by the BioMass Balance approach, was selected and blended with the cycloaliphatic hydrocarbon resin Escorez 5300. Various oil-to-resin ratios were investigated, and a linear increase in the T_g of the vulcanizate was obtained when increasing the resin content and decreasing the oil content. Additionally, a 50/50 blend, consisting of 18.75 phr Hexamoll DINCH and 18.75 phr Escorez 5300, resulted in the same T_g of −19 °C as a compound containing 37.5 phr TDAE. Furthermore, this blend resulted in similar curing characteristics and cured Payne effect as the reference with TDAE. Moreover, a similar rolling resistance indicator (tan δ at 60 °C = 0.115), a slight deterioration in wear resistance (ARI = 83%), but an improvement in the stress–strain behavior (M300 = 9.18 ± 0.20 MPa and Ts = 16.3 ± 0.6 MPa) and wet grip indicator (tan δ at 0 °C = 0.427) were observed. The results in this work show the potential of finding a balance between optimal performance and sustainability by using plasticizer blends. Full article

Fischer–Tropsch synthesis (FTS) facilitates the conversion of syngas, derived from feedstocks such as biomass, coal, and natural gas, into valuable hydrocarbons (HCs). This investigation employed optimization methods, specifically Gibbs energy minimization, to perform a thermodynamic characterization of the low-temperature Fischer–Tropsch (LTFT) reaction for HC generation. The CONOPT3 solver within GAMS 23.2.1 software was utilized for solving the developed model. To represent the complex FTS product spectrum, twenty-three compounds, encompassing C₂–C₂₀ aliphatic hydrocarbons, were considered using a stoichiometric framework. The study explored the impact of operational parameters, including temperature (350–550 K), pressure (5–30 bar), and H₂/CO molar feed ratio (1.0–2.0/0.5–1.0), on hydrocarbon synthesis. Evaluation of the outcomes focused on HC yield and product characteristics. A significant sensitivity of the reaction to operating parameters was observed. Notably, lower temperatures, elevated pressures, and a H₂/CO ratio of 2.0/1.0 were identified as optimal for fostering the formation of longer-chain HCs. The developed model demonstrated robustness and efficiency, with rapid computation times across all simulations. Full article

This work concerns the preparation of Pt/AC catalysts (Pt supported on activated carbon) and their application to the synthesis of hydrocarbon biofuels through the HEFA (hydroprocessing of esters and fatty acids) route. The key motivation for the work was that catalysts based on sulfided Mo supported on γ-Al₂O₃, traditionally employed in the hydroprocessing of petroleum derivatives, (i) are unstable in the HDO (hydrodeoxygenation) of biomass-derived feedstocks and (ii) can contaminate the resulting biofuels with sulfur. In this context, a systematic study on the effects of preparation conditions on the properties of the resulting Pt/AC catalysts and their performance in HEFA was carried out for the first time. Efficient catalysts were obtained, which led to the complete deoxygenation of lauric acid and coconut oil, yielding products composed primarily of n-alkanes. The highest HDO activity was verified for the catalyst prepared using as a support an AC previously subjected to thermal treatment up to 800 °C in a H₂ atmosphere (which removed most of the surface acidic oxygenated groups), depositing Pt over the surface of this support via wet impregnation using a H₂PtCl₆ solution acidified with HCl. The obtained results showed the great potential of the Pt/AC catalysts for the production of hydrocarbon biofuels through the HEFA route. Full article

This paper presents the results of a study of the catalytic hydrogenation of phenanthrene using catalysts based on chrysotile modified with nickel and titanium (chrysotile/NiTi), as well as coal shale. Complex characterization of catalysts in terms of acid, texture and morphological properties was carried out. Pre-reduction in the catalysts has been found to increase the yield of partially and fully hydrogenated products, including tetrahydronaphthalene, trans-decalin and dihydrophenanthrene. Particular attention is paid to the role of coal shale as a donor source of hydrogen in thermolysis conditions. The results of hydrogenation revealed complex mechanisms of phenanthrene transformations, including partial saturation of aromatic rings, desulfurization and the formation of alkyl-substituted compounds. The obtained data emphasize the prospects of using the studied catalysts in the processes of processing heavy and solid hydrocarbon raw materials, which opens up opportunities for creating new technologies for the production of liquid fuel. Full article

Polycyclic aromatic hydrocarbons (PAHs) in biochar, as opposed to those in pyrolysis liquid products that exit the reactor without adhering to the solid product, are particularly undesirable due to their environmental persistence and potential toxicity. When applied as a soil amendment, biochar containing PAHs poses risks to soil ecosystems and human health. Their formation during pyrolysis presents a significant challenge in biochar production, requiring the optimization of pyrolysis process parameters to minimize PAH content for safe soil amendment applications. This study explored the effects of particle size and heating rate on PAH formation during corn cob pyrolysis. Thermogravimetric analysis (TGA) was employed to heat corn cob powder of varying sample masses from ambient temperature to 550 °C at heating rates of 5, 10, and 20 °C/min. Simultaneously, the Chemical Reaction Engineering and Chemical Kinetics (CRECK) model simulated the pyrolysis of spherical corn cob biomass particles with a radius ranging from 1 to 40 mm, using feedstock chemical compositions as inputs. Tar species generated from the solid biomass model were introduced into a gas-phase batch reactor model to evaluate PAH formation. The results demonstrate that the particle size and heating rate significantly affect PAH formation, shedding light on the complex dynamics of biomass pyrolysis. A single spherical particle with a radius close to 1 mm approximates ideal TGA conditions by minimizing temperature and mass transfer limitations. The CRECK model suggested that a particle radius of 5–10 mm, combined with a low heating rate of 5 °C/min, optimally reduces PAH formation. Future research should focus on using thermogravimetric analysis coupled with gas chromatography–mass spectrometry (TGA-GC-MS) to comprehensively quantify PAH species formation. Full article

Single-ring aromatic compounds including BTX (benzene, toluene, xylene) serve as essential building blocks for high-performance fuels and specialty chemicals, with extensive applications spanning polymer synthesis, pharmaceutical manufacturing, and aviation fuel formulation. Current industrial production predominantly relies on non-renewable petrochemical feedstocks, posing the dual challenges of resource depletion and environmental sustainability. The catalytic hydrodeoxygenation (HDO) of lignin-derived phenolic substrates emerges as a technologically viable pathway for sustainable aromatic hydrocarbon synthesis, offering critical opportunities for lignin valorization and biorefinery advancement. This article reviews the relevant research on the conversion of lignin-derived phenolic compounds’ HDO to benzene and aromatic hydrocarbons, systematically categorizing and summarizing the different types of catalysts and their reaction mechanisms. Furthermore, we propose a strategic framework addressing current technical bottlenecks, highlighting the necessity for the synergistic development of robust heterogeneous catalysts with tailored active sites and energy-efficient process engineering to achieve scalable biomass conversion systems. Full article

The study of thermal developments of heavy oil feedstock, vacuum residue in particular, is a relevant factor for the development of technologies for the processing and production of petroleum products. This paper investigates the process of thermal decomposition of the vacuum residue in the manufacturing of catalyst and polymer material using thermal analysis methods, including thermogravimetric analysis (TGA) in isothermal and dynamic modes. Particular attention is paid to the measurement of kinetic parameters of thermolysis using model and non-model methods, which allows us to assess the output power and other kinetic characteristics of decomposition. The results obtained can be used for the development of new oil refining technologies for significantly increasing the efficiency and safety of processes. During the course of this study, experimental and theoretical activation energy values were obtained for the vacuum residue without a catalyst (experimentally: 91.54 kJ mol⁻¹/theoretically: 91.35 kJ mol⁻¹) and a sample with the presence of a catalyst (experimentally: 89.68 kJ mol⁻¹/theoretically: 90.87 kJ mol⁻¹). The reduction in activation energy in the presence of the catalyst confirms its catalytic activity and potential for processing heavy hydrocarbon feedstock. Full article

This study investigates the potential of biochar derived from agricultural residues—corn cob and wheat straw—for removing polycyclic aromatic hydrocarbons (PAHs) from aqueous systems. Biochars were produced via pyrolysis at 700 °C and characterized using BET, SEM, EDS, FTIR, and pXRD to evaluate physicochemical properties. Adsorption experiments with naphthalene, fluorene, fluoranthene, and pyrene revealed high adsorption affinities (Log Kd = 4.35–5.69 L/kg), with Freundlich isotherm modeling indicating nonlinear behavior (n = 0.732–0.923), suggesting a combination of pore filling and chemical interactions such as π-π stacking and hydrogen bonding. Corn-cob biochar, rich in lignin, exhibited a higher surface area (111 m²/g) and greater affinity for fluorene, while wheat-straw biochar, with a higher oxygen content and more functional groups, performed better for naphthalene and pyrene. FTIR and pXRD confirmed aromatic and graphitic structures facilitating PAH interactions. These results underscore the importance of feedstock selection and pyrolysis conditions in tailoring biochar properties for specific pollutants. While both biochars compare favorably with conventional adsorbents like activated carbon, further research on long-term stability in complex matrices is needed. Overall, the findings support the development of cost-effective, scalable, and eco-friendly biochar-based technologies for water remediation. Full article

The innovative recycling of waste tires into fuel is essential for promoting sustainable development, enhancing waste valorization, and advancing waste-to-energy technologies. For the processing of fr. ≤ 200 °C, separated from the liquid products of the pyrolysis process of waste tires, polycondensation with formaldehyde and extraction with a polar solvent (N-methyl-2-pyrrolidone) was used. Due to the sequential application of these processes, a raffinate product is produced that contains significantly fewer undesirable compounds, such as reactive unsaturated hydrocarbons and aromatics, which can negatively affect gasoline. Additionally, this raffinate demonstrates chemical stability during storage. Due to its operational properties, the obtained raffinate can serve as a high-quality component for gasoline production, which is advisable when mixed with low-octane gas condensate. As a result of compounding, Euro 4 gasoline is obtained with an octane number equal to 93 according to the experimental method. The possibility of effectively using the extract (concentrate of aromatic and unsaturated compounds) as a plasticizer for waterproofing mastic was shown. Overall, the valorization of waste tire pyrolysis processing contributes to waste reduction and is consistent with promoting sustainable industrial innovation by replacing primary petrochemical feedstocks with secondary feedstocks and supporting the development of alternative energy sources. Full article