Search Results (102)

This study investigates the thermo-hydro-mechanical (THM) coupling impacts on seepage and heat transfer characteristics to enhance the efficient utilization of hot dry rock resources in the Guanzhong Basin. A computational model of thermo-hydro-mechanical three-field coupling for an enhanced geothermal system is developed based on the geological context and rock thermophysical properties of the Huazhou-Huayin target area in the Guanzhong Basin. The effects of differential pressure during injection and production, injection temperature, and well configuration on the reservoir stress field, permeability variations, temperature distribution, and heat recovery efficiency of the system are carefully simulated and analyzed. Simulations indicate that increasing the injection–production pressure differential from ±1 MPa to ±7 MPa dramatically enhances heat recovery, yielding a fivefold increase in the extraction rate and an 11.54-fold rise in cumulative heat production. Conversely, this aggressive approach severely impacts long-term sustainability, accelerating thermal breakthrough and drastically cutting the operational lifespan by 93.30%. Lowering the injection temperature from 60 °C to 20 °C yields a 24.14% enhancement in heat output over the same duration, together with a 24.14% increase in the geothermal extraction rate. Increasing the number of injection–production wells from one to two broadens the heat extraction range and improves system heat production by 35.82%, concurrently diminishing lifespan by 39.50%. This work possesses theoretical importance for the progression of hot dry rock initiatives similar to those in the Guanzhong Basin and other geological settings. Full article

The effect of palladium addition to a hybrid Co/SiO₂ + HZSM-5 + Al₂O₃ catalyst on the combined Fischer–Tropsch (FT) synthesis and hydrocarbon hydroconversion process was studied. Catalysts with a Pd content of 0.075–0.3 wt.% were characterized by a complex of physicochemical methods, including synchrotron radiation X-ray diffraction (SR-XRD), temperature-programmed reduction with hydrogen (H₂-TPR), temperature-programmed desorption of hydrogen with oxygen titration (H₂-TPD/O₂ titration), IR spectroscopy of adsorbed pyridine, and STEM-EDX analysis. It was found that the addition of palladium decreases the cobalt oxide reduction temperature due to interphase hydrogen transfer. Tests in hydrocarbon synthesis at 240–250 °C, a pressure of 2 MPa, and an H₂/CO ratio of 2 showed that the sample with 0.15% Pd exhibits the highest selectivity for C₅+ hydrocarbons (66.8% at 240 °C) and stability for 150 h. Analysis of the synthesis products revealed a fivefold decrease in the proportion of alkenes and an increase in isoalkanes with increasing Pd concentration. This effect enables the in situ hydroprocessing of primary FT products in a single reactor. The results demonstrate that the targeted introduction of palladium into the hybrid system is an effective strategy for regulating its functionality, allowing for the one-stage production of high-quality fuels with a controlled hydrocarbon composition from syngas. Full article

This paper explores the complex interrelationships between biomass composition, thermochemical conversion pathways, carbon yield and other characteristics in order to expand the knowledge for biomass conversion processes and adapt them to specific requirements. A comprehensive characterization, chemical and thermal analysis of peach stone biomass, was performed. Thermogravimetric analysis, elemental analysis and low-temperature nitrogen sorption were also carried out in order to establish the composition and textural characteristics of the precursor material and obtained product. Carbon adsorbents were obtained from the studied biomass precursor under different conditions via one-step hydro-pyrolysis process by using steam activation at 800 °C. After research was conducted, it was established that cellulose is the main component, which influences the quantity and quality of the obtained adsorbent. The high content of hemicellulose reveals peach stones as a good candidate, especially for hydrothermal carbonization. High cellulose content (40%) in the biomass precursor is a prerequisite for the formation of porous texture in carbon adsorbent during hydro-pyrolysis. It was also shown that the carbon yield (26.70%) can be predicted and is highly dependent on the precursor composition. These results highlight the potential of peach stones as a valuable precursor for the production of sustainable, high-performance carbon adsorbents for environmental remediation. Full article

This study investigates transboundary hydro-meteorological trends in the Upper Po River basin, adopting a multi-perspective framework to disentangle the joint evolution of climatic and hydrological drivers. We analyzed climatic variables from 25 weather stations (1950–2022) alongside streamflow data from 14 river sections (1911–2022). Trends were assessed using the Mann–Kendall test to detect monotonic changes and the Theil-Sen estimator to quantify magnitude, ensuring robustness against outliers. The results reveal pronounced warming, particularly in spring maximum temperatures with +0.95 ± 0.40 °C per decade, and +0.62 ± 0.35 °C per decade at the annual scale. Conversely, average and minimum daily temperatures show lower rates with, respectively, +0.50 ± 0.26 °C and +0.39 ± 0.27 °C at the annual scale. Consequently, potential evapotranspiration increased significantly (+15.1 ± 9.4 mm per decade), likely contributing to a marked decline in summer streamflow in 8 out of 14 sections. Correlation analysis confirms that snow dynamics modulate the hydrological response: precipitation drives discharge annually and in autumn, winter exhibits a weaker coupling, as winter precipitation is partially stored in the basin as snow, contributing to discharge during spring and summer. By focusing on this strategic region for European agriculture and industry, the study provides useful insights into the combined effects of warming and evapotranspiration on water availability for adaptation strategies. Full article

The utilization of sustainable feedstocks offers significant opportunities for innovation in sustainable and efficient processing technologies, targeting a vacuum residue upgrade industry projected to be valued at around USD 26 billion in 2024. This review examines advances in catalytic strategies for upgrading waste-derived products (plastics, tires) and biomass, in addition to heavy oil feedstocks. Particular emphasis is placed on hydrogen addition pathways, specifically, residue hydroconversion facilitated by dispersed nanocatalysts and waste co-processing methodologies. Beyond nanoscale catalyst design and reaction performance, this work also addresses refinery-level sustainability impacts. The advanced catalytic conversion of heavy oil residue demonstrates superior conversion efficiency, significant coke suppression, and improved carbon utilization, while life cycle and illustrative techno-economic comparisons indicate greenhouse gas reductions and a net economic gain of approximately USD 2–3 per barrel relative to conventional refining under scenarios assuming decarbonized hydrogen production. Co-processing of plastics, tires, and biomass with heavy oil feedstocks is highlighted as a practical and effective approach. Together, these findings outline a rational catalytic pathway toward optimized refining systems. Within the framework of the circular carbon economy, these catalytic processes enable enhanced feedstock utilization, integration of low-carbon hydrogen, and coupling with carbon-capture technologies. Full article

Organic photovoltaics (OPVs) based on non-fullerene acceptors (NFAs) are rapidly advancing as lightweight, flexible, and low-cost solar technologies, with power conversion efficiencies approaching 20%. To ensure that environmental sustainability progresses symmetrically alongside performance improvements, it is essential to quantify the environmental footprint of these emerging technologies, particularly during early development stages when material and process choices remain adaptable. This study presents a cradle-to-gate life cycle assessment (LCA) of PTB7-Th:ZY-4Cl solar cells, aiming to identify asymmetries in environmental impact distribution and guide eco-efficient optimization strategies. Using laboratory-scale fabrication data, global warming potential (GWP), cumulative energy demand (CED), acidification (AP), eutrophication (EP), and fossil fuel depletion (FFD) were evaluated via the TRACI methodology. Results reveal that electricity consumption in thermomechanical operations (ultrasonic cleaning, spin coating, annealing, and stirring) disproportionately dominates most impact categories, while chemical inputs such as PEDOT:PSS, PTB7-Th:ZY-4Cl precursors, and solvents contribute significantly to fossil fuel depletion. Substituting grid electricity with renewable sources (hydro, wind, PV) markedly reduces GWP, and solvent recovery or replacement with greener alternatives offers further gains. Although extrapolation to a 1 m² pilot-scale module reveals impacts higher than established PV technologies, prospective scenarios with realistic efficiencies (10%) and lifetimes (10–20 years) suggest values of ~150–500 g CO₂-eq/kWh—comparable to fullerene OPVs and approaching perovskite and thin-film benchmarks. These findings underscore the value of early-stage LCA in identifying asymmetrical hotspots, informing material and process optimization, and supporting the sustainable scale-up of next-generation OPVs. Full article

A combined Differential InSAR (D-InSAR) and Digital Elevation Model (DEM)-based analysis revealed that earthquake-triggered landslides significantly altered river morphology and intensified flooding in the Kota Belud catchment, Sabah, Malaysia. This 1386 km² catchment, home to about 120,000 people, has experienced a marked rise in flood events following the 4 June 2015 and 8 March 2018 earthquakes. Multi-temporal Sentinel-1 Synthetic Aperture Radar (SAR) data and a 30 m Shuttle Radar Topography Mission (SRTM) DEM, complemented by river network information from HydroBASINS, were integrated to map sediment redistribution and model flood extent. Upstream zones exhibited extensive coseismic landslides and pronounced geomorphic disruption. Interferometric analysis showed that coherence was well preserved over stable terrain but rapidly degraded in vegetated and steep areas. Sediment aggradation, interpreted qualitatively from patterns of coherence loss and increased backscatter intensity, highlights slope failure initiation zones and depositional build-up along channels. Conversely, downstream, similar sedimentary adjustments were detected immediately upstream of areas with repeated flood incidents. Between 2015 and 2018, flood occurrences increased over fivefold, and after 2018, they increased by more than thirteenfold relative to pre-2015 conditions. DEM-based inundation simulations demonstrated that channel shallowing substantially reduced conveyance capacity and expanded flood extent. Collectively, these results confirm that earthquake-induced landslides have contributed to reshaping the geomorphology and amplified flooding in the area. Full article

The conversion of polycyclic aromatic hydrocarbons (PAHs) to monocyclic aromatic hydrocarbons holds significant importance in the petrochemical and coal chemical industries, as it enables the production of high-value-added chemicals. In this study, we investigated the methane-assisted hydroconversion of PAHs to monocyclic aromatic hydrocarbons with methyl side chains over Zn-based catalysts from Hβ zeolites treated with citric acid (CA) at different concentrations. The CA-modified Hβ catalysts were characterized using X-ray diffraction (XRD), N₂ adsorption–desorption, pyridine–Fourier transform infrared spectroscopy (Py-FTIR), and ammonia temperature-programmed desorption (NH₃-TPD). The results show that low CA concentrations facilitate the removal of amorphous aluminum from the zeolite framework, thereby increasing the specific surface area, pore volume, and pore diameter of the Zn/Hβ catalyst, as well as improving its Lewis/Brønsted (L/B) acid ratio. In contrast, excessive CA treatment causes the undesirable removal of framework aluminum and leads to structural collapse in the mesoporous regions formed at the interfaces between certain crystal aggregates. This, in turn, has a negative impact on the catalyst’s specific surface area, pore volume, pore size distribution, total acidity, and L/B ratio. Experimental data further indicate that the optimal Zn/Hβ catalyst, prepared using Hβ treated with 0.08 M CA, achieves a naphthalene conversion rate of up to 99% and a benzene–toluene–xylene (BTX) selectivity of 60% in the liquid product over a 10 h reaction period. These findings confirm that CA treatment not only enhances the catalytic activity of Zn/Hβ but also significantly improves its operational stability. This work provides new insights into the rational design of catalysts for the efficient conversion of PAHs to monocyclic aromatic hydrocarbons and the utilization of methane resources. Full article

The growing demand for air connectivity, coupled with the forecasted increase in passengers by 2040, implies an exigency in the aviation sector to adopt sustainable approaches for net zero emission by 2050. Sustainable Aviation Fuel (SAF) is currently the most promising short-term solution; however, ensuring its overall sustainability depends on reducing the life cycle carbon footprints. A key challenge prevails in hydrogen usage as a reactant for the approved ASTM routes of SAF. The processing, conversion and refinement of feed entailing hydrodeoxygenation (HDO), decarboxylation, hydrogenation, isomerisation and hydrocracking requires substantial hydrogen input. This hydrogen is sourced either in situ or ex situ, with the supply chain encompassing renewables or non-renewables origins. Addressing this hydrogen usage and recognising the emission implications thereof has therefore become a novel research priority. Aside from the preferred adoption of renewable water electrolysis to generate hydrogen, other promising pathways encompass hydrothermal gasification, biomass gasification (with or without carbon capture) and biomethane with steam methane reforming (with or without carbon capture) owing to the lower greenhouse emissions, the convincing status of the technology readiness level and the lower acidification potential. Equally imperative are measures for reducing hydrogen demand in SAF pathways. Strategies involve identifying the appropriate catalyst (monometallic and bimetallic sulphide catalyst), increasing the catalyst life in the deoxygenation process, deploying low-cost iso-propanol (hydrogen donor), developing the aerobic fermentation of sugar to 1,4 dimethyl cyclooctane with the intermediate formation of isoprene and advancing aqueous phase reforming or single-stage hydro processing. Other supportive alternatives include implementing the catalytic and co-pyrolysis of waste oil with solid feedstocks and selecting highly saturated feedstock. Thus, future progress demands coordinated innovation and research endeavours to bolster the seamless integration of the cutting-edge hydrogen production processes with the SAF infrastructure. Rigorous techno-economic and life cycle assessments, alongside technological breakthroughs and biomass characterisation, are indispensable for ensuring scalability and sustainability. Full article

The article presents the material composition of the titanium- and iron-rich ilmenite concentrate from the Satpayev deposit in Eastern Kazakhstan, which is unacceptable for processing by commercial hydro- and pyrometallurgical enrichment methods due to the presence of rutile, soluble only in hydrofluoric acid, and many refractory aluminosilicate associations: kaolinite, kyanite, pyrophyllite and mullite, cementing titanium minerals. The solution to the problem of reducing the cost of titanium sponge production was developed by developing an economically efficient and environmentally safe technology for the conversion of clayey ilmenite sand concentrate, including thermal activation of particularly resistant raw materials in an air atmosphere, soda-carbothermic smelting of cinder, hydrothermal refining of titanium slag with water, then hydrochloric acid and regeneration of reagents. Oxidative roasting ensures disintegration of intergrowths and destruction of mineral grains of the concentrate. The addition of soda ash to the concentrate cinder batch accelerates the reduction and agglomeration of over 98% of the iron, prevents the formation of lower refractory titanium oxides, facilitates the stratification of the thin-flowing titanium slag melt and cast iron and significantly reduces energy costs and the duration of the carbothermic smelting process. Refining primary titanium slag with water provides the production of modified slag with a mass fraction of TiO₂ of at least 83% and FeO of no more than 0.4%, suitable for the production of high-quality titanium sponge. Subsequent refining of modified titanium slag with 20% hydrochloric acid yields synthetic rutile of 96% purity, surpassing in the content of the main substance the branded titanium pigments of the American company DuPont. The resource-saving and environmental significance of this innovative technology is increased by the possibility of recycling easily regenerated soda, hydrochloric acid and recyclable carbon dioxide released during the decomposition of the alkaline reagent during the carbothermic smelting of the concentrate. Full article

Wetlands, as critical ecological systems, face increasing threats from anthropogenic pressures and climate change. This study investigates dynamic water allocation strategies for the restoration of Lake Marmara, a nationally important wetland within the Gediz River Basin of Türkiye, which has experienced complete desiccation in recent years. Within the scope of the PRIMA-funded “Mara-Mediterra” project, an integrated modeling approach was employed to evaluate multiple restoration scenarios using the WEAP (Water Evaluation and Planning) platform. Scenarios varied based on the initial storage capacity of Gördes Dam, irrigation demands, environmental flow priorities, and a potential water diversion investment from the Tabaklı reach. Results indicate that under current conditions, Lake Marmara’s ecological water needs can be sustained without the Tabaklı investment. However, under 2050 climate projections, scenarios lacking the Tabaklı investment or deprioritizing ecological needs consistently failed to meet the lake’s minimum water thresholds. Conversely, scenarios combining moderate dam storage levels, environmental prioritization, and Tabaklı inflow succeeded in restoring lake volumes by over 90%. These findings highlight the need for adaptive water planning that aligns with projected hydro-climatic shifts to ensure long-term wetland sustainability. Full article

This study used widely available waste biomass, corn cob (CC), to remove Pb ions from aqueous solutions. A two-step conversion of this material was carried out to improve its adsorption characteristics. Firstly, CC was prepared by hydrothermal carbonization; afterward, the obtained hydrochar was doped by MgCl₂ and pyrolyzed. The synthesized hydro-pyrochar (HCC-Mg) was used for adsorption experiments in a batch system. The surface and structural properties of HCC-Mg were characterized by SEM-EDX and FTIR analysis before and after Pb adsorption. Kinetic and isotherm models were applied to the experimental results. It was confirmed that Pb adsorption on HCC-Mg occurred rapidly, with a maximum adsorption capacity of 87.08 mg/g. The pseudo-second-order model best described the adsorption process, while the best fit of the experimental data was observed with the Sips isotherm model. The results of this study showed that the capacity of the synthesized HCC-Mg material had increased more than 14 times compared with raw CC. In addition, the synthesized material had the potential to be reused for at least five cycles with minimal loss of adsorption capacity and efficiency. Moreover, the results confirmed that HCC-Mg can be used as an efficient, sustainable adsorbent of Pb from polluted water. Full article

This study investigates slope stability under rainfall infiltration using numerical modeling in Plaxis 2D, comparing poorly graded sand (6.5% fines) and well-graded sand (11.9% fines) under high-intensity rainfall of 30 mm/h for durations of 8, 12, 18, and 24 h. The results indicate that, as rainfall duration increases, soil saturation rises, leading to reduced suction, lower shear strength, and decreased safety factors (S.F.s). Poorly graded sand shows minimal sensitivity to infiltration, with the S.F. dropping by only 4.3% after 24 h, maintaining values close to the initial 1.126. Conversely, well-graded sand demonstrates significant sensitivity, with its S.F. decreasing by 25.4% after 8 h and 73.7% after 24 h, due to higher water retention capacity and suction. This highlights the significant contrast in stability behavior between the two soil types. The findings emphasize the critical role of soil hydro-mechanical properties in assessing slope stability, especially in regions with intense rainfall. This study establishes a methodology for correlating safety factor variations with rainfall duration and soil type, offering valuable insights for modeling and mitigating landslide risks in rainy climates, considering the hydraulic and mechanical parameters of the soil. Full article

Hybrid pumped hydro storage plants, by integrating pump stations between cascade hydropower stations, have overcome the challenges associated with site selection and construction of pure pumped hydro storage systems, thereby becoming the optimal large-scale energy storage solution for enhancing the absorption of renewable energy. However, the multi-energy conversion between pump stations, hydropower, wind power, and photovoltaic plants poses challenges to both their planning schemes and operational performance. This study proposes a multistage stochastic coordinated planning model for cascade hydropower-wind-solar-thermal-pumped hydro storage (CHWS-PHS) systems. First, a Hybrid Pumped Hydro Storage Adaptive Initial Reservoir Capacity (HPHS-AIRC) strategy is developed to enhance the system’s regulation capability by optimizing initial reservoir levels that are synchronized with renewable generation patterns. Then, Non-anticipativity Constraints (NACs) are incorporated into this model to ensure the dynamic adaptation of investment decisions under multi-timescale uncertainties, including inter-annual natural water inflow (NWI) variations and hourly fluctuations in wind and solar power. Simulation results on the IEEE 118-bus system show that the proposed MSSP model reduces total costs by 6% compared with the traditional two-stage approach (TSSP). Moreover, the HPHS-AIRC strategy improves pumped hydro utilization by 33.8%, particularly benefiting scenarios with drought conditions or operational constraints. Full article

In this study, a statistical analysis of results reported in the literature was conducted through a 2ⁿ experimental design on the synthesis of bifunctional catalysts used in the production of lighter fuels, aiming for optimization while considering factors such as support (bentonite and vermiculite), acidity modifier (zirconium and cerium), metal (tungsten and molybdenum), metal content (5% and 10%), promoter (nickel and cobalt), and heteropolyacids (tungstophosphoric acid and molybdophosphoric acid), identifying their influence on textural properties and catalytic performance. Regarding the textural properties, vermiculite proved to be the most favorable support due to its high porosity. It was also established that the implemented metals impart positive characteristics to the catalysts due to their various properties; however, incorporating large amounts led to an adverse effect by clogging the pores. Catalytic performance was analyzed in isomerization and cracking reactions, which were enhanced by the use of cerium due to the presence of Brønsted acid sites and molybdenum for its stability. In this way, the statistical analysis conducted in this study was crucial for identifying the influence of key factors on the textural properties and catalytic performance of bifunctional catalysts. Using a 2ⁿ experimental design allowed for a systematic evaluation of variables reported in the literature, such as support, acidity modifiers, metals, metal content, promoters, and heteropolyacids. Full article