Search Results (210)

Soil salinity severely limits grapevine (Vitis spp.) growth and productivity, yet the mechanisms distinguishing tolerant and sensitive rootstocks remain incompletely understood. We compared the salt-tolerant rootstock ‘SO4’ with the salt-sensitive ‘Beida’ under 100 mmol L⁻¹ NaCl for 0, 6, and 12 days. Salinity progressively reduced photosynthetic pigments in both genotypes, although ‘SO4’ retained higher levels. Salt treatment also increased hydrogen peroxide, malondialdehyde, soluble sugars, soluble proteins, proline, and antioxidant enzyme activities. Compared with ‘Beida’, ‘SO4’ showed stronger osmotic adjustment and greater activation of superoxide dismutase, peroxidase, catalase, and ascorbate peroxidase. RNA-seq analysis revealed extensive genotype- and time-dependent transcriptional reprogramming, with differentially expressed genes mainly associated with hormone signalling, secondary metabolism, carbon fixation, protein processing, and lipid metabolism. Weighted gene co-expression network analysis identified the MEblack module as positively associated with salt tolerance in ‘SO4’ but negatively associated with ‘Beida’. Within this module, Vitvi01g00735/VvBCA2 and Vitvi07g02043/VvLCB1 were prioritized as candidate hubs based on high module membership, gene significance, and intramodular connectivity. Hub-centred networks linked VvBCA2 to redox regulation, protein homeostasis, defense, and osmotic signalling, whereas VvLCB1 was associated with cell-wall remodelling, methyl metabolism, membrane signalling, and lipid turnover. Transcription-factor families, including MYB, WRKY, AP2/ERF, bHLH, and HSF, were more strongly represented in ‘SO4’. Collectively, these findings identify coordinated physiological and transcriptional mechanisms underlying salt tolerance and provide candidate genes for grapevine improvement. Full article

Current industrial standards for gas pipeline leak testing often assume inert testing gases are universally interchangeable, neglecting specific fluid dynamics. This study quantifies how testing gas properties affect integral pressure decay leak tests. Experimental measurements (5000 Pa initial pressure) were conducted on a PE100RC (polyethylene resistant to crack propagation) pipe assembly with artificial capillary defects (0.13 mm diameter) using five media: nitrogen, air, argon, carbon dioxide, and a propane−butane (PB) mixture. Results demonstrate that in the continuous viscous flow regime, leak rates depend strictly on the gas’s dynamic viscosity. For identical defects, PB (the lowest viscosity gas tested) increased the leak rate by up to 129% compared to standard nitrogen. This relationship is statistically validated by a strong negative Pearson correlation (r = −0.92). To facilitate industrial application, a preliminary mathematical correction procedure is proposed for safely extrapolating these trends to infrastructure intended for pure hydrogen operation. To prevent false-positive tightness certifications during the transition to low-viscosity alternative fuels like pure hydrogen, implementing a dynamic viscosity correction factor is essential. Full article

Bioenergy with carbon capture, utilization, and storage (BECCUS) is increasingly regarded as a potential pathway to achieve net-negative emissions and support deep decarbonization. This review examines BECCUS from the perspective of circular carbon systems by integrating biomass resources, bioenergy conversion, carbon capture technologies, storage and utilization pathways, economic feasibility, sustainability challenges, and policy requirements. To improve conceptual clarity, the review distinguishes among BECCS, BECCU, and BECCUS based on carbon retention time, lifecycle boundaries, and final product fate. Recent advances in carbon capture technologies, including absorption, adsorption, membrane separation, chemical looping, cryogenic separation, direct air capture, and hybrid systems, are reviewed with particular attention to biomass-based applications. Major utilization and storage pathways are also critically assessed, including geological storage, CO₂-enhanced recovery, cement mineralization, CO₂-to-chemicals, CO₂-to-fuels, microalgae-based conversion, and agricultural CO₂ utilization. These pathways are compared in terms of technology readiness, mitigation potential, permanence, energy demand, economic feasibility, and major limitations. A bibliometric analysis is further included to identify research hotspots and emerging trends. Overall, BECCUS is a promising but highly pathway-dependent option whose climate benefits depend on sustainable biomass supply, lifecycle emissions, low-carbon hydrogen, infrastructure availability, and consistent carbon accounting. Full article

Associated gas in the Permian Basin is a methane-rich but spatially fragmented and intermittently available feedstock. Methane pyrolysis can convert hydrocarbons to hydrogen and solid carbon without forming process CO₂ in the reactor, but its practical value depends on the captured-gas capacity factor, feed composition, high-temperature heat supply, product purification, continuous carbon withdrawal, carbon offtake, and transparent greenhouse-gas accounting. This study presents an implemented screening model for a modular 1 million standard cubic feet per day (MMSCFD) Permian associated-gas unit. A representative Permian composition is evaluated with hydrocarbon cracking stoichiometry, catalytic and thermal conversion envelopes, a net hydrogen recovery assumption, an energy-duty allocation, a levelized-cost model, and a well-to-gate carbon-intensity model. The catalytic base case produces 3.78 t/d of saleable H₂ after 90% pressure-swing adsorption (PSA) recovery and 14.27 t/d of solid carbon; the thermal near-complete conversion bound produces 4.31 t/d of saleable H₂ and 16.15 t/d of solid carbon. At a 0.85 capacity factor, $10 million installed capital expenditure (CAPEX), 8% real discount rate, 20-year life, 10 kWh per kg H₂ energy intensity, and $0.06 per kWh electricity, the deterministic plant-gate levelized cost of hydrogen (LCOH) is $1.81 per kg H₂ at zero carbon value and $1.05 per kg H₂ at a net realized carbon value of $0.20 per kg C. Monte Carlo analysis over capacity factor, CAPEX, energy intensity, electricity price, carbon value, feed/capture cost, and yield uncertainty gives levelized cost of hydrogen values at the 10th, 50th, and 90th percentiles (P10/P50/P90) of $1.32/$1.91/$2.57 per kg H₂. The corresponding screening carbon-intensity distribution is 2.34/4.11/5.89 kg carbon dioxide equivalent (CO₂e) per kg H₂, dominated by electricity carbon intensity and upstream methane loss. Geothermal or waste-heat preheat is treated quantitatively as a partial offset to low- and mid-temperature duties, not as a replacement for high-grade 900–1200 °C trim heat. The pathway is benchmarked against steam methane reforming, autothermal reforming with carbon capture and storage, electrolysis, small-scale liquefied natural gas, and gas-to-liquids conversion. Reported LCOH values are plant-gate production costs; separate hydrogen-logistics and negative-carbon-value stress tests identify conditions under which remote delivery or carbon disposal can erode the apparent economic advantage. Full article

As a chemical element, manganese is used in a wide range of industries, particularly steelmaking and creating alloys and as a sacrificial coating for corrosion protection. Electrodeposition is a low-energy process; however, manganese electrodeposition from aqueous solutions remains challenging due to the highly negative reduction potential of Mn²⁺. The addition of group VI elements such as selenium, sulfur or tellurium to the electrolyte improves both coating quality and the current efficiency of manganese electrodeposits by suppressing the competing hydrogen evolution reaction (HER). While selenium and sulfur compounds are widely studied electrolyte additives, research on the use of tellurium additives in the electrolyte and their influence on the manganese electrodeposition process and subsequent coating properties remains limited. In this work, manganese electrodeposits were obtained from a manganese ammonium sulfate bath (MASB) electrolyte with a sodium tellurate(VI) additive at both room and elevated temperatures. The resulting coatings, which also underwent a phosphating process to enhance the corrosion resistance of the coating, were investigated for properties such as morphology, elemental composition, and corrosion resistance; all corrosion tests were carried out in a 3% NaCl solution. The findings show that coatings deposited at higher temperatures exhibit a more compact surface structure, with α-Mn becoming more abundant as the MASB temperature increases. Furthermore, higher-temperature deposition produces coatings with greater current efficiency, though at the cost of a higher concentration of incorporated tellurium. Finally, the coatings that underwent the phosphating were evaluated against untreated (uncoated and non-phosphated) mild carbon steel regarding their corrosion resistance. Full article

Excessive cathodic polarization of underground stainless steel structures results in hydrogen evolution, increasing the risk of hydrogen embrittlement and the disbonding of protective coatings from the structure’s surface. This study was conducted to determine the critical potential and critical cathodic protection current density at which hydrogen evolution occurs on the surfaces of stainless steel grades 1.4301, 1.4401, 1.4125, and 1.4512, and, for comparison, on carbon steel S235. The tests were carried out in an aqueous solution of synthetic (artificial) soil and in a soil filtrate prepared from a soil sample taken in the vicinity of an existing underground gas pipeline connection with stainless steel fittings. The tests showed that the higher the chromium content in the stainless steel was, the lower (more negative) the hydrogen evolution potential was. In an artificial soil environment, the values of this potential ranged from −1105 mV to −1175 mV vs. copper sulphate electrode (CSE) for steels 1.4301, 1.4401, and 1.4125, which contain more than 16% of chromium. For steel 1.4512, containing 12% of chromium, the hydrogen evolution potential was −1050 mV. For comparison, for S235 carbon steel, the hydrogen evolution potential was −1135 mV. The critical cathodic protection current density ranged from 0.30 A/m² to 0.38 A/m² for all tested stainless steels, whilst for S235 steel, this value was higher, equal to 0.65 A/m². The results obtained indicate that applying the commonly accepted potential criterion for cathodic protection for carbon steels (i.e., polarization to a potential in the range from −0.85 V to −1.1 V vs. CSE) poses no risk of causing excessive cathodic polarization of stainless steel. This is important for the design and operation of cathodic protection systems for complex structures containing galvanically connected carbon steel and stainless steel components. Full article

This study investigates citrus peel powder (CP) as an environmentally friendly admixture to regulate plant-derived urease (with soybean powder (SP) as the urease source) and to promote bio-mediated CaCO₃ mineralization, thereby improving the mechanical and freeze–thaw (FT) resistance properties of cement-based materials. When CP is combined with urea and soybean urease, it exhibits a regulatory effect on urease activity. For the CPUD (CP-encapsulated urea combined with soy powder)-modified material with SP dosage in cement content of 0.2 wt%, the CP–urea modification treatment can effectively improve their mechanical properties and FT durability. The flexural and compressive strengths at 28 days are increased by 10.53% and 11.19%, respectively, compared to the blank group. After freeze–thaw cycles, the strengths are still 27.08% and 26.67% higher than those of the blank group, and their respective strength loss rates are 7.58% and −5.77% (negative indicating a net strength increase), compared with 21.31% and 9.48% for the blank group. X-ray diffraction, Fourier-transform infrared spectroscopy, and scanning electron microscopy analyses reveal that CP–urea promotes the formation and effective packing of calcium carbonate. Mechanistically, CP establishes a stable hydrogen-bonding network with both urea and urease, exerting a dual regulatory effect: it enhances the electrophilicity of urea while also creating a physical mass transfer barrier to precisely control biomineralization. Notably, CP can be directly used without pretreatment, offering a sustainable strategy for citrus peel waste valorization. Full article

The role of internal combustion engines in future transport systems is expected to remain central, particularly in hard-to-abate sectors such as heavy-duty road transport and maritime applications. However, their decarbonization requires the adoption of low-carbon and renewable fuels. This review examines hydrogen, methane-based fuels, methanol, and ethanol for internal combustion engine applications using a pathway-based approach that integrates life-cycle assessment, technology readiness level, commercial readiness level, and engine-related considerations. The reviewed literature shows that the environmental performance of these fuels varies strongly depending on feedstock, production pathway, process configuration, and energy source. From a Well-to-Tank perspective, hydrogen pathways exhibit particularly large variability, ranging from around 3 gCO₂eq/MJ for wind-based electrolysis to around 230 g CO₂eq/MJ for coal gasification. Methane-based fuels range from around 16 gCO₂eq/MJ for fossil compressed and liquefied natural gas to negative values for waste- and manure-based biomethane. Methanol and ethanol also show substantial variability, with renewable, waste-derived, and bio-based pathways generally offering substantially lower life-cycle greenhouse gas (GHG) emissions than fossil-based routes. In the use phase, Tank-to-Wheel analysis shows that energy demand remains relatively similar across fuels, while differences in direct emissions are mainly related to fuel carbon content and other GHG species such as ${\mathrm{CH}}_4$ or ${\mathrm{H}}_2$ slip and combustion-related species such as ${\mathrm{N}}_2\mathrm{O}$. The Well-to-Wheel comparison for heavy-duty applications highlights that upstream fuel production pathways strongly influence overall performance, while use-phase contributions play a secondary role and mainly affect the final ranking when upstream emissions are comparable. Overall, the review shows that pathway selection is more influential than fuel identity itself, highlighting that effective decarbonization strategies should focus on pathway design and upstream fuel production rather than on fuel categories alone, and that renewable and bio-based pathways offer the greatest potential for achieving very low or near-zero life-cycle GHG emissions in internal combustion engine applications. Full article

Given the critical need for scalable technologies that decouple industrial production from fossil feedstocks, this study introduces a green hydrogen-driven and carbon-negative industrial complex that employs renewable energy to simultaneously produce methanol and Fischer–Tropsch hydrocarbon products via feedstocks of carbon dioxide (CO₂) and water. The proposed complex (FARMOW) integrates six major sections: (i) a Fischer–Tropsch synthesis process (FTSP), (ii) an alkaline water electrolysis process (AWEP), (iii) a reverse water–gas shift process (RWGSP), (iv) a methanol synthesis process (MSP), (v) an off-gas combustion process (OGCP), and (vi) a water treatment process (WTP). In this complex, the green hydrogen produced from AWEP is reacted with CO₂ from a carbon capture unit and sent to the MSP and FTSP sections, respectively, to generate methanol and Fischer–Tropsch hydrocarbon products. The byproduct (water) from the complex is utilized to generate steam through rigorous process simulation, and the technical efficacy of the complex has been modeled and validated, yielding high-value hydrocarbons, methanol, steam, and oxygen. Furthermore, a comprehensive techno-economic assessment with sensitivity analysis is performed to evaluate the commercial flexibility of the system under varying market conditions. Full article

Per- and polyfluoroalkyl substances (PFASs) are persistent environmental contaminants whose mobility in soil and groundwater is strongly controlled by adsorption and desorption processes. In saturated clay-rich soils, these processes are complex because PFASs interact with hydrated mineral surfaces, organic matter, metal oxides, exchangeable cations, and pore-water constituents. This review synthesizes the current literature on PFAS adsorption and desorption in saturated soils, with an emphasis on clay mineralogy, mineral–water interfaces, pore-water chemistry, and electrochemical double layer (EDL) effects. PFAS retention is influenced by molecular properties such as chain length, functional head group, and charge state, as well as soil properties such as organic carbon content, clay mineral type, surface charge, cation exchange capacity, and Fe/Al oxide content. Longer-chain PFASs and sulfonate-based compounds generally show stronger retention, while shorter-chain PFASs tend to remain more mobile. This review focuses particularly on how an EDL affects PFAS behavior in saturated clay systems. Unlike dry clay surfaces, saturated clay surfaces are covered by structured water, exchangeable ions, and diffuse counterion layers. These hydrated interfacial conditions influence how closely anionic PFASs can approach negatively charged clay surfaces, how dissolved cations reduce electrostatic repulsion or promote cation-mediated binding, and how effectively short-range interactions such as hydrophobic association, van der Waals forces, hydrogen bonding, and surface association contribute to adsorption. Desorption is also emphasized because adsorption does not necessarily represent permanent immobilization. Changes in pH, ionic strength, cation composition, dissolved organic matter, or competing solutes can weaken retention and promote PFAS release. Overall, PFAS mobility in saturated clay-rich soils should be interpreted as a coupled interfacial process rather than simple partitioning to soil solids. Future work should better connect molecular-scale mechanisms, EDL behavior, adsorption–desorption experiments, and saturated transport studies to improve predictions of PFAS retention and long-term groundwater release. Full article

Hydrogen production from waste plastics is emerging as a potential low-carbon pathway that integrates waste management with energy production. This study develops an integrated socio-technical framework combining a comparative assessment of thermochemical conversion pathways with market acceptance analysis based on survey data (n = 162). The results show that acceptance is mainly driven by trust (β = 0.47) and environmental perception (β = 0.32), while price sensitivity has a negative effect (β = −0.21). Awareness does not significantly affect acceptance (β = 0.08). The model explains 48% of the variance (R² = 0.48), and a strong correlation is observed between trust and acceptance (r = 0.68). These results show that technological performance alone is insufficient; consumer perception and economic factors play an equally important role, highlighting the need for integrated socio-technical approaches in low-carbon energy systems. Full article

To address transportation-related emissions, Taiwan’s 2022 net-zero strategy sets targets to increase the adoption of battery electric vehicles (BEVs). However, current policy frameworks insufficiently consider the technological diversity of low-emission alternatives, particularly hydrogen fuel cell electric vehicles (FCEVs). This study integrates a well-to-wheel life cycle assessment (LCA) with system dynamics modeling to evaluate and compare the environmental and health impacts of transitioning from internal combustion engine vehicles (ICEVs) to BEVs and hydrogen FCEVs. The framework incorporates LCA-based carbon emissions and disability-adjusted life years (DALYs) into a dynamic population simulation. Results show that, while DALY effects on life expectancy and population growth are limited, low-carbon vehicle adoption substantially reduces environmental burdens and helps moderate population decline. Projections to 2050 highlight significant emission-reduction potential, with hydrogen FCEV carbon emissions decreasing as renewable energy in hydrogen production increases. Adoption of green hydrogen could achieve a net-negative carbon balance for hydrogen FCEVs by 2049, positioning them as a sustainable long-term alternative to BEVs. Full article

This study explores a photovoltaic/thermal (PV/T)-based electrolysis system designed for dual production of hydrogen fuel and domestic hot water (DHW), providing a sustainable energy solution amid rising global emissions. A dynamic rule-based control mechanism with hysteresis thresholds on hydrogen-storage state of charge (SoC) is implemented to balance electrolyzer operation with intermittent solar availability, maintaining PV/T power outputs while preventing storage overfilling and minimizing start–stop cycling. The system is assessed across 27 geographically diverse cities spanning a wide range of solar irradiation and energy price structures. Annual hydrogen yields range from 20 kg/yr in high-latitude locations (Helsinki, Stockholm) to 33.5 kg/yr in high-irradiation regions (Riyadh, Abu Dhabi), while the levelized cost of hydrogen (LCOH) spans from 6.47 USD/kg (Riyadh) to 22.86 USD/kg (Helsinki). Economically, the system achieves its strongest performance in solar-rich, high-energy-cost environments: Rome records the highest net annual cash flow (858.9 USD/yr) and shortest payback period (2.47 years), followed by Davos, Madrid, Brasília, and Canberra. In contrast, locations with subsidized energy tariffs—such as Algiers, Kyiv, and Tehran—yield low or negative net cash flows, rendering the system economically unviable without policy support. Environmental analysis reveals annual CO₂ avoidance ranging from 0.33 ton/yr (Stockholm) to 2.97 ton/yr (Riyadh), with a global mean of 1.095 ton/yr and a combined total of approximately 29.6 tons/yr across all examined sites. A machine learning model is developed to generalize performance predictions across unseen locations, achieving leave-one-out (LOO) R² values of 0.953 (net cash flow), 0.935 (LCOH), and 0.947 (LCO-DHW), with mean absolute errors below ±1 USD/kg and ±0.03 USD/kWh. The findings confirm that, under fixed capital cost assumptions, local electricity price and solar irradiation are the dominant drivers of economic viability, while grid carbon intensity and solar resource jointly govern environmental performance, with markets offering irradiation above 1500 kWh/m²·yr and electricity prices exceeding 0.2 USD/kWh representing the most promising deployment targets. Full article

The integration of catalytic methane decomposition (CMD) with CO₂ gasification (Reverse Boudouard Reaction) offers a promising chemical looping route for carbon-negative hydrogen and syngas production. This work systematically investigates the gasification reactivity of six carbon morphologies, CNTs, CNFs, activated carbon, graphite, graphene, and CMD-derived carbon, with and without Ni addition. First, activity tests and characterization (XRD, XPS, Raman) revealed that CMD-derived carbon outperformed all other benchmarks due to its highly amorphous nature (sp³/sp² = 0.98), which provides a high density of reactive sites. Second, kinetic analysis showed that the incorporation of 5 wt% Ni on CMD carbon reduced the activation energy (E_a) from 435.3 kJ mol⁻¹ to 114.6 kJ/mol, the lowest among all samples. This 74% reduction confirms that structural defects in CMD carbon act as anchoring sites for Ni, facilitating a strong metal–support interaction (MSI) that promotes CO₂ activation. Third, an investigation into structural synergy revealed that higher Ni loadings (>5 wt%) increased the activation energy (up to 171.2 kJ mol⁻¹). This trend is attributed to Ni agglomeration and weakened MSI, which reduces the active catalytic interface. These findings demonstrate that the efficiency of CO₂ valorization is highly sensitive to carbon morphology, providing a clear optimization strategy for integrated chemical looping methane-to-syngas energy cycles. Full article

Underground Gas Storage (UGS) is transitioning from traditional fossil fuel peak-shaving facilities into comprehensive hubs for Terawatt-hour-scale Terawatt-hour (TWh) scale renewable energy storage. The unique physicochemical properties of diverse fluids, such as the negative Joule–Thomson coefficient of hydrogen (−0.03 K/bar), present complex engineering adaptability challenges. Since existing studies primarily focus on single mechanisms or specific geological types, this review integrates a unified engineering framework to evaluate the repurposing potential and retrofitting requirements of existing oil and gas assets. By compiling a property benchmarking matrix for methane, carbon dioxide, and hydrogen, the storage adaptability of various geological formations is summarized. Salt caverns exhibit strong adaptability to highly diffusive and reactive fluids due to their high salinity (exceeding 150 g/L) and mechanical stability, whereas porous media offer massive capacity (more than 10 times) but require overcoming severe biogeochemical obstacles. Based on thermo–hydro–mechanical–chemical–biological (THMCB) coupling mechanisms, an integrity evaluation system for artificial wellbore and natural geological barriers is systematically reviewed. Critical risks, including fatigue failure under high-frequency cyclic loading, material degradation, gas leakage, and indirect Global Warming Potential (GWP), are elucidated. A future evolution route integrating physical, digital, and policy dimensions is outlined. This roadmap emphasizes Hydrogen-Enriched Compressed Natural Gas (HCNG)synergistic storage, dynamic risk control utilizing digital twins and Artificial Intelligence (AI), and standardized Life Cycle Assessment mechanisms (LCA), providing a scientific basis for the sustainable transition of UGS facilities. Full article