Search Results (70)

Against the background of the “dual carbon” goals and the integration of a high proportion of renewable energy, hydrogen energy storage, with its advantages of long duration and large scale storage as well as clean energy conversion, has become an important approach to improving the flexibility and security of energy systems. To address the accident risks associated with leakage from high pressure hydrogen storage in stationary hydrogen energy storage facilities, this study takes an integrated hydrogen energy storage station involving hydrogen production, storage, compression, and utilization as the research object. A numerical model for hydrogen leakage and dispersion from high-pressure storage cylinders in an open environment is established to investigate the effects of leakage aperture, natural ventilation, mechanical ventilation, and emergency shutdown on hydrogen cloud evolution and deflagration risk. The results show that an increase in leakage diameter significantly increases the flammable hydrogen volume and Q9 peak value. Large-scale leakage is prone to local accumulation under the influence of blast walls and obstacles, resulting in a 780 m³ combustible volume and 14.7 m³ Q9; medium-scale leakage has a longer duration, whereas small-scale leakage presents the lowest risk. Under natural wind conditions, crosswind provides better dilution, reducing Q9 by 53%. Mechanical ventilation can effectively reduce the value of Q9 by 36%, with ventilation layout exerting a more significant influence than wind speed. The combined use of mechanical ventilation and emergency shutdown can further reduce the 42% flammable volume and shorten the duration of high concentration hydrogen clouds. The findings can provide guidance for the safety layout, ventilation design, and emergency protection of hydrogen energy storage stations. Unlike conventional CFD-based leakage consequence analyses, this study couples hydrogen dispersion simulation with Q9-based deflagration risk assessment and a hierarchical safety strategy involving natural, mechanical ventilation, and emergency shutdown. Full article

Thick paint coatings on ship hulls must be periodically removed before repainting; however, conventional abrasive blasting generates secondary waste and poses environmental and occupational health concerns. This study investigates nanosecond pulsed laser cleaning as a non-contact alternative for removing thick marine paint coatings from KE36 shipbuilding steel. A two-layer coating system consisting of anti-fouling and anti-corrosive layers with a total thickness of approximately 1000 μm was examined. The effects of pulse energy, pulse overlap number, and scanning pitch on removal depth, cleaning efficiency, and surface morphology were systematically evaluated. Increasing the pulse energy enhanced coating ablation and enabled complete removal when sufficient heat input density was supplied. A higher pulse overlap number promoted cumulative energy deposition and improved removal depth. Smaller scanning pitches improved spatial overlap between adjacent scan paths and produced more uniform cleaning, whereas excessive pitches caused incomplete removal and periodic surface undulations. The cleaning efficiency approached 100% at a heat input density of approximately 4–5 J/mm². These results indicate that heat input density is a useful process indicator for determining the minimum energy conditions required for full removal of thick coating layers while minimizing thermal effects on the substrate. Full article

Published laboratory data on soil stabilisation are abundant, yet they remain fragmented across studies and are often difficult to reuse because of inconsistent reporting formats, heterogeneous testing conditions, and incomplete metadata. This article presents a curated experimental dataset compiled from 20 published studies on fine-grained soils, comprising 560 records, including 397 unconfined compressive strength (UCS) results and 163 California Bearing Ratio (CBR) results. The dataset is defined by the inclusion of laboratory studies designed around biopolymer-based two-additive stabilisation frameworks, while intentionally retaining untreated and single-additive comparator records reported within the same experimental programmes. This design is a key distinguishing feature of the dataset because it enables analysis of baseline soil behaviour, isolated additive effects, and combined-additive responses within a traceable study context. Across the included studies, the treatment systems cover a wide range of biopolymer- and lignin-related materials, including xanthan gum, guar gum, chitosan, sodium lignosulfonate, and electrolyte lignin stabiliser, together with complementary additives such as cement, lime, fly ash, ground granulated blast-furnace slag, rice husk ash, glass powder, concrete waste, nano-additives, and natural or synthetic fibres. In addition to UCS and CBR outcomes, the dataset preserves key contextual variables required for meaningful secondary reuse, including soil classification, grain-size fractions, Atterberg limits, compaction properties, curing duration, additive identities and dosages, and source-level traceability. The data are distributed as a structured Excel workbook comprising two cleaned outcome-specific sheets (CBR_clean and UCS_clean) and four supporting documentation sheets (StudyInventory, DataDictionary, VocabularyMap, and QC_Log). Record-level identifiers, DOI-linked source fields, inferred-curing flags, and qualified outcome descriptors are retained to support auditability, selective filtering, and reproducible reuse. The resulting dataset provides a practical foundation for comparative assessment of stabilisation strategies, pavement and subgrade engineering studies, meta-analysis, and machine learning applications in geotechnical engineering. Full article

The development of cementitious materials with multifunctional performance is increasingly important to address environmental demands and durability requirements in modern infrastructure. This study investigates calcium sulfoaluminate (CSA) cement partially substituted with blast furnace slag (BFS), fly ash (FA), and TiO₂ nanoparticles, aiming to combine sustainability with photocatalytic self-cleaning functionality. Phase analysis by X-ray diffraction confirmed the formation of characteristic CSA hydration products, including ettringite, ye’elimite, anhydrite, and calcite, indicating that partial substitution did not disrupt the primary hydration mechanisms. Microstructural observations revealed that the incorporation of BFS, FA, and TiO₂ induced noticeable morphological changes, with increased porosity and microstructural heterogeneity at higher replacement levels. Mechanical testing showed that moderate BFS contents of 5 to 10 wt% enhanced compressive strength in reference mixtures, while systems containing TiO₂ exhibited slightly lower strength values and increased dispersion, particularly at elevated slag contents. The photocatalytic performance, evaluated through Rhodamine B degradation under solar irradiation, demonstrated a marked improvement for TiO₂-containing samples, reaching degradation efficiencies of up to 80%, in contrast to negligible activity in unmodified systems. These results confirm that the combined use of industrial by-products and photocatalytic nanoparticles in CSA-based matrices represents a viable strategy for producing sustainable cementitious materials with added environmental functionality, without compromising fundamental structural performance. Full article

This study investigates the effects of laser and cryogenic (dry ice) surface treatments on enhancing surface characteristics of Ti-6Al-4V titanium alloy components produced using the Selective Laser Melting (SLM) technique. Components produced via additive manufacturing often exhibit increased surface irregularities and residual unmelted powder, which can deteriorate their mechanical strength and resistance to corrosion. In this study, SLM samples manufactured with two laser powers (176 W and 220 W) were subjected to laser cleaning and dry ice blasting under various process parameters. Surface topography and morphology analyses were performed. The obtained results showed that both methods improved surface uniformity and removed contaminants. Dry ice treatment effectively removed loose powder particles and impurities without causing structural changes—the best results were obtained at a pressure of 10 bar. Laser treatment, depending on the focal length, produced varying degrees of surface remelting—from gentle smoothing (500 mm) to intensive thermal effects and microcracks (250 mm). The research confirmed that cryogenic cleaning is an environmentally friendly and safe post-processing method, while laser cleaning enables deeper surface structure modification, requiring further optimization. Full article

High-phosphorus oolitic iron ores (HPOIOs) possess abundant reserves but are incompatible with conventional blast furnace ironmaking, as phosphorus migrates into hot metals during carbothermic reduction, preventing the production of low-phosphorus clean steel. To overcome this limitation, an innovative approach integrating alkaline briquette direct reduction and smelting separation was proposed. Briquettes were prepared from oolitic magnetite concentrate (52.01 wt% Fe, 0.29 wt% P, 0.11 wt% S) with a basicity (R) of 2.0 and 5 wt% MgO added as a desulfurizer. After direct reduction and smelting separation, the resulting metallic iron exhibited a content of 98.56 wt% Fe, with 0.036 wt% P and 0.046 wt% S, achieving an Fe recovery of 87.63%. The dephosphorization and desulfurization efficiencies reached 94.67% and 90.56%, respectively, meeting the clean steel requirements. Phosphorus was effectively stabilized within the gehlenite and merwinite phases as a solid solution of Ca₃(PO₄)₂, inhibiting its transfer to iron. Thermodynamic analyses confirmed that high basicity (R ≥ 2.0) significantly suppressed P₂O₅ activity, preventing phosphate reduction. The formation of a Ca₃(PO₄)₂–Ca₂SiO₄ solid solution further obstructed phosphorus migration. This dual mechanism of “chemical fixation and thermodynamic stabilization” enables efficient dephosphorization, offering a sustainable pathway for utilizing HPOIOs. Full article

In order to alleviate the energy crisis and respond to the “dual carbon strategy”, a new energy substance is needed to replace pulverized coal as the new blast furnace blowing fuel. Hydrochar is a clean and renewable carbon resource with high calorific value, good transportation and storage properties, and low ash content. Numerical simulation is used to study the combustion process of co-blown pulverized coal and hydrochar inside the cyclone zone. In this study, a three-dimensional physical model was constructed based on the actual dimensions of the direct-blowing pipe, tuyere, coal gun, and swirl zone of a large blast furnace in China. Numerical simulation methods were used to study the combustion process of coal powder and hydrothermal carbon co-injected into the swirl zone, and to investigate changes in the swirl zone of the tuyere under different conditions. The results show that increasing the proportion of hydrochar in the blended coal is conducive to improving the combustion rate of the blended coal, the temperature inside the gyratory zone increases significantly with the increase in the oxygen enrichment rate, and the high temperature zone is gradually enlarged. For every 1% increase in the oxygen enrichment rate, the maximum temperature of the centerline of the coal plume increases by 28 K, and the burnout rate increases by 1.12%; the increase in the blast temperature makes the combustion of pulverized coal slightly advance and promotes the increase in the internal temperature of the gyratory zone. The change of the blast temperature to 1559 K is more obvious, and the increase in the blast temperature after it is greater than 1559 K is not significant for the improvement of the burnout rate and the temperature of the gyratory area, and it will increase the cost; the lower the proportion of the small particle size is, the bigger the high temperature area of the gyratory area is, and the higher the temperature of the centerline of the coal strand is. If the content of the volatile matter remains unchanged, the increase in the ratio of the hydrochar has little influence on the temperature field of the gyratory area and the temperature of the centerline of the coal strand. The temperature difference is kept at 20 K. With the increase in the hydrochar ratio, the overall burnout rate of pulverized coal gradually increases. Therefore, hydrochar can replace bituminous coal as blast furnace blowing fuel to a certain extent, which can reduce costs and carbon emissions. Full article

The escalating global water crisis, coupled with the unsustainable accumulation of industrial and urban waste, demands innovative solutions that align with circular economy principles. This review explores the transformative potential of waste-derived ceramic membranes as a sustainable strategy for water purification, simultaneously addressing waste valorization and clean water scarcity. Ceramic membranes, traditionally fabricated from high-purity inorganic materials, are renowned for their superior chemical resistance, thermal stability, and durability. Recent advances demonstrate that industrial byproducts, such as red mud, coal fly ash, blast furnace slag, coal gangue, and kiln roller waste, can be effectively repurposed into cost-effective, high-performance filtration materials. This paper critically examines fabrication techniques, material properties, and performance metrics of waste-derived ceramic membranes. By transforming industrial waste into functional filtration materials, this approach not only mitigates environmental pollution but also contributes to sustainable water security. Full article

Glycerol, a byproduct of biodiesel, has moderate energy but high viscosity, making clean combustion challenging. Quickly evaporating fine fuel sprays mix well with air and burn cleanly and efficiently. Unlike conventional air-blast atomizers discharging a jet core/film, a newly developed swirl burst (SB) injector generates fine sprays at the injector’s immediate exit, even for high-viscosity fuels, without preheating, using a unique two-phase atomization mechanism. It thus resulted in ultra-clean combustion for glycerol/methanol (G/M) blends, with complete combustion for G/M of 50/50 ratios by heat release rate (HRR). Lower combustion efficiencies were observed for G/M 60/40 and 70/30, representing crude glycerol. Hence, this study investigates the effect of premixed methane amount from 0–3 kW, and the effect of atomizing gas to liquid mass ratio (ALR) on the dual-fuel combustion efficiency of G/M 60/40-methane in a 7-kW lab-scale swirl-stabilized gas turbine combustor to facilitate crude glycerol use. Results show that more methane and increased ALR cause varying flame lift-off height, length, and gas product temperature. Regardless, mainly lean-premixed combustion, near-zero CO and NOx emissions (≤2 ppm), and ~100% combustion efficiency are enabled for all the cases by SB atomization with the assistance of a small amount of methane. Full article

Dry ice blasting is a technology that has been widely studied and applied in different industrial sectors as an alternative to the use of solvent, water, or abrasive spraying methods. It is a CO₂ spraying system capable of balancing efficiency and sustainability with a wide variety of equipment available on the market. This study analyses and compares cryo-cleaning equipment manufactured by pioneering companies in the cryogenic industry. Based on data sheets, safety data sheets, and contact with manufacturers, a quantitative comparative study has been carried out. The aim of this study is to identify those with the best performance, efficiency, and adaptability to operational and environmental requirements. The results reflect the strengths and weaknesses of the equipment in terms of occupational safety and operability. These have been discussed and evaluated, recognising improvements of this technology, which is capable of removing surface layers of different natures without altering the underlying substrate. Full article

This study evaluated the potential of incorporating TiO₂ nanoparticles (NT) into cementitious composites to provide self-cleaning and self-sanitising properties, as well as the partial replacement of natural aggregates with recycled glass (RGA), ceramic brick (RBA), granulated blast furnace slag (GBA), and textolite waste (RTA) from electronic equipment on these properties. Based on the research results, the addition of NT to cementitious composites led to a significant reduction in contact angle, which means an increase in surface hydrophilicity. At the same time, Rhodamine B stain fading was highlighted, with the degree of whiteness recovery of NT composites exceeding that of the control by up to 11% for natural aggregate compositions, 10.6% for RGA compositions, 19.9% for RBA compositions, 15% for GBA compositions, and 13% for RTA compositions. In a mould-contaminated environment, it was shown that the introduction of NT allowed the material to develop a biocidal surface capacity which is also influenced by the nature of the aggregates used. Furthermore, the study revealed that, under controlled conditions, certain recycled waste aggregates, such as textolite, promoted mould growth, while others, such as brick and slag, inhibited it, highlighting not just the effect of the addition of NT, but also the significant influence of the aggregate type on the microbial resistance of cementitious composites. These improvements in the performance of cementitious composites are particularly advantageous when applied to prefabricated elements intended for the finishing and decorative surfaces of institutional (schools, administrative buildings, religious structures, etc.) or residential buildings. Full article

Unauthorised graffiti is a challenge in urban environments, affecting railway structures, stations, tracks, and vehicles. Inefficient cleaning methods increase the costs and downtime of railcars, limiting passenger transport. In turn, they are harmful to the operator’s health and the environment, due to the VOCs they release. This study focuses on the feasibility of dry-ice blasting, replacing carbon dioxide with ambient air as an innovative and sustainable solution to remove graffiti from rail vehicles. Experimental tests have been carried out with 13 different aerosols, controlling the temperature (<−80 °C), pressure (up to 3 bar), projection distance (0.5 cm) and exposure times (30″/1′/2′/4′/6′/8′/++). The results showed that ultra-freezing with ambient air preserved the integrity of the support materials and altered the topography, colourimetry and adhesion of the aerosols tested, achieving the total removal of one of the paints. Preliminary results suggest that ultra-freezing with ambient air could be a viable and sustainable solution for graffiti removal on railway structures, transferable to other urban environments. Full article

Solving the challenges facing the mining industry is crucial for shaping the global attitude towards clean energy technologies associated with critical minerals extracted from depth. One of these challenges is the well-known explosion-like fractures (rockbursts) or spalling failures associated with the initiation of internal cracks. To prevent such catastrophic failure, shotcrete, as a cement grout, is widely used in tunnel support applications. In areas where the tunnels are constructed within the limestone strata using tunnel boring machines (TBM), drilling, and/or blasting, millions of cubic meters of crushed limestone (CL) in powder form are extracted and landfilled as waste. Given the fact that natural sand consumption as a raw material in the construction industry exceeds previous records, recycling of such excavation material is now becoming increasingly needed. From this perspective, this study aims to utilize crushed limestone as a potentially sustainable alternative to natural sand in shotcrete applications in deep tunnels. Accordingly, several strength characterization and crack initiation determinations through various stress–strain-based models were carried out on cylindrical samples containing different proportions of crushed limestone. By increasing the crushed limestone content in the shotcrete mix, the crack initiation stress (as a measure of the in situ spalling strength) increased as well. The results suggest that the crushed limestone has good potential to replace the natural sand in the shotcrete mixture used in tunnel support applications. Full article

Soil microbial fuel cells (SMFCs) are bioelectrical devices powered by the oxidation of organic and inorganic compounds due to microbial activity. Seven soils were randomly selected from Bergen Community College or areas nearby, located in the state of New Jersey, USA, were used to screen for the presence of electrogenic bacteria. SMFCs were incubated at 35–37 °C. Electricity generation and electrogenic bacteria were determined using an application developed for cellular phones. Of the seven samples, five generated electricity and enriched electrogenic bacteria. Average electrical output for the seven SMFCs was 155 microwatts with the start-up time ranging from 1 to 11 days. The highest output and electrogenic bacterial numbers were found with SMFC-B1 with 143 microwatts and 2.99 × 10⁹ electrogenic bacteria after 15 days. Optimal electrical output and electrogenic bacterial numbers ranged from 1 to 21 days. Microbial DNA was extracted from the top and bottom of the anode of SMFC-B1 using the ZR Soil Microbe DNA MiniPrep Protocol followed by PCR amplification of 16S rRNA V3-V4 region. Next-generation sequencing of 16S rRNA genes generated an average of 58 k sequences. BLAST analysis of the anode bacterial community in SMFC-B1 demonstrated that the predominant bacterial phylum was Bacillota of the class Clostridia (50%). However, bacteria belonging to the phylum Pseudomonadota (15%) such as Magnetospirillum sp. and Methylocaldum gracile were also part of the predominant electrogenic bacterial community in the anode. Unidentified uncultured bacteria accounted for 35% of the predominant bacterial community. Bioelectrical devices such as MFCs provide sustainable and clean alternatives to future applications for electricity generation, waste treatment, and biosensors. Full article

The demand for materials with improved properties and less negative impact on the environment is growing. Artificial stones are examples of these materials produced with up to 90% of particulate material joined by a binder. This article evaluates the physical and mechanical properties of two artificial stones produced with processing steel residue (blast furnace dust waste) and quartz powder. Two binders were used: pure epoxy resin, denoted as ASPB100, or a mixture of 70 wt% epoxy resin with 30 wt% cashew nut shell oil, denoted as ASPB7030. The process took place under vibration, compression (3 MPa/20 min and 90 °C) and vacuum (80 Pa). ASPB100 showed water absorption of 0.07%, while for ASPB7030, it was 0.54%. They were classified as having high mechanical strength associated with bending stress values equal to 32 and 25 MPa, respectively. Stain resistance indicated that both artificial stones had their stains removed with the tested cleaning agents. In this way, the novel artificial stones produced are sustainable alternatives for the application of blast furnace waste and cashew nut shell oil, reducing their negative impacts on the environment. Full article