Search Results (1,566)

Coal-fired power generation remains a major source of carbon dioxide (CO₂) emissions, and metal–organic framework-74 (MOF-74) materials offer high adsorption capacity but rely on costly 2,5-dihydroxyterephthalic acid linkers that limit scalability. This study synthesized bimetallic Zn_0.75Mg_0.25-MOF-74 using terephthalic acid (TPA) as a cheaper alternative linker and evaluated the effect of synthesis reaction temperature (89–160 °C) and time (5–55.5 h) on its physicochemical properties for carbon capture. Samples were prepared solvothermally and characterized by FTIR, XRD, SEM-EDS, and N₂ (77 K) and CO₂ (293 K) adsorption analysis. FTIR confirmed metal–ligand coordination; XRD verified crystalline MOF-74 formation, and SEM showed well-defined rod-like morphology at 100 °C, 12 h and 125 °C, 30 h. Direct CO₂ adsorption on the 125 °C, 30 h sample yielded a Type I isotherm characteristic of micropore filling, with an uptake of 0.31 mmol/g at ~1 bar and 0.072 mmol/g at flue-gas-relevant conditions (~0.135 bar). Its CO₂-derived BET surface area (60.10 m²/g) and Dubinin–Astakhov micropore area (131.69 m²/g) far exceeded N₂-derived values, confirming ultra-micropores accessible to CO₂ but not to N₂ at 77 K. TPA therefore yields a stable, microporous CO₂-adsorbing framework, trading some capacity for lower cost and scalability. Future investigations should systematically evaluate long-term cycling stability and adsorption performance under mixed-gas operating conditions. Full article

Achieving sustainable industrial transformation under carbon neutrality constraints requires breaking the high-carbon lock-in of the chemical sector through renewable-based production pathways. Green methanol, produced via CO₂ hydrogenation using green hydrogen and captured industrial CO₂, represents a critical technological option for decarbonizing methanol production while enabling circular utilization of industrial carbon emissions. Existing research on green methanol cost generally treats the CO₂ feedstock cost as a uniform national constant, thereby obscuring the economic heterogeneity of different industrial CO₂ sources and their spatial coupling with provincial renewable resource endowments, which limits the granularity of decision support for regionally differentiated green methanol deployment. This study constructs an integrated sustainability assessment framework for green methanol in China, systematically differentiating four typical post-combustion industrial CO₂ source scenarios—steel, cement, coal-fired power and coal–chemical industries. By integrating the levelized cost of electricity (LCOE) model, green hydrogen production cost accounting, and provincial-level CO₂ capture cost trajectories, the framework forecasts the provincial green methanol production cost across 29 Chinese provinces from 2030 to 2060. The results show that (1) under the four industrial CO₂ source scenarios, China’s provincial green methanol cost declines persistently between 2030 and 2060, with the coal–chemical source achieving the lowest cost (2032–3434 CNY/t) and the coal-fired power source the highest (2168–3565 CNY/t) in 2060. (2) The spatial pattern shows a stable “low costs in the Three-North region and high costs in southeastern and central China” differentiation, with Qinghai, Gansu, Inner Mongolia and Xinjiang positioned below 2500 CNY/t in 2060, reflecting the resource–environment coupling mechanism governing sustainable deployment of renewable-based chemical production. (3) Green hydrogen accounts for 76.4–80.9% of total cost while CO₂ capture accounts for 4.1–10.1%, so that inter-provincial cost spread within any scenario is governed almost entirely by green hydrogen cost, whereas the choice of industrial CO₂ source shifts the cost level of a given province. (4) Traditional industrial provinces such as Hebei and Jilin attain near-term cost competitiveness comparable to northwestern resource-rich provinces by combining locally available low-cost CO₂ sources with a favorable renewable generation mix, though this advantage narrows towards 2060. These findings provide scientifically grounded pathways for China’s sustainable chemical industry transition, supporting the coordinated achievement of industrial decarbonization (SDG 9), climate action (SDG 13), and responsible consumption and production (SDG 12), while offering actionable guidance for spatially differentiated sustainable development policies that maximize economic and environmental co-benefits. Full article

Wildfire impact assessment requires information on both burned areas and the biomass exposed within burned landscapes. We developed a field-calibrated, multi-source remote-sensing framework to estimate above-ground biomass (AGB) and quantify annual wildfire-related potential AGB exposure across the boreal forests of Quebec and Ontario, Canada, during 2018–2024. The dataset comprised 3725 plot-year AGB observations linked to optical, Sentinel-1 C-band, ALOS L-band synthetic aperture radar, environmental, and geographic predictors. Product-wise screening reduced the 91 candidate predictors to 28. An optimized extreme gradient boosting (XGBoost) model was evaluated using five-fold grouped cross-validation, with repeated observations from each plot assigned to a single fold. The model achieved an RMSE of 25.08 ± 0.36 t ha⁻¹, an MAE of 20.89 ± 0.39 t ha⁻¹, and an R² of 0.53 ± 0.02. The full multi-source configuration outperformed all reduced-source and source-only configurations, while removing ALOS L-band SAR or environmental/geographic predictors produced among the largest performance declines. The model was applied to 9937 land-cover-stratified points within wildfire polygons using predictors from the year preceding each fire. Under the complete-loss assumption, cumulative potential AGB exposure was 269.20 Mt across 6.66 Mha of effective burned area, with a 95% bootstrap interval of 254.19–284.06 Mt reflecting finite-point sampling uncertainty and an area-weighted mean exposure intensity of 40.43 t ha⁻¹. The 2023 fire season accounted for 206.44 Mt, representing 76.7% of cumulative exposure and 73.2% of effective burned area. Effective burned area and total potential exposure were strongly correlated (r = 0.99), whereas exposure intensity followed a distinct pattern and peaked in 2022 at 46.86 t ha⁻¹. Thus, burned area was the primary correlate of regional potential biomass exposure, whereas exposure intensity reflected variation in pre-fire biomass among burned landscapes. These estimates represent potential exposure rather than measured combustion, mortality, or carbon emissions and demonstrate the value of integrating spatially explicit pre-fire AGB with wildfire perimeters. Full article

Prescribed fire is an effective tool for reducing wildfire risk but emits pollutants such as carbon monoxide (CO) and fine particulate matter (PM_2.5) that negatively impact both indoor and outdoor air quality. While emissions from prescribed fires have been widely characterized, there remains limited understanding of how emissions vary across combustion conditions, fuel types, and regions. More specifically, there has been little work that has looked at both emissions of CO and PM_2.5 as well as other compounds such as elemental carbon (EC), organic carbon (OC), and speciated organic compounds. This work quantifies the variability of emission factors (EFs) for CO, PM_2.5, EC, OC, and speciated organic compounds across 19 prescribed fires in Colorado and southeastern Georgia using low-cost sensors. This allowed us to have highly temporally resolved EF datasets across multiple monitors and multiple burns. Results show that CO EFs are strongly driven by combustion phases, with higher emissions associated with lower modified combustion efficiency, or smoldering combustion (+3260%). However, PM_2.5 EFs exhibit weaker and more variable relationships with combustion phase and are more strongly influenced by fuel type (+108% for Colorado-based fuels) and burn characteristics (+8.3%). Broadcast burns generally exhibited higher CO and PM_2.5 EFs than pile burns, while daytime burning conditions were associated with lower emissions for both CO and PM_2.5. The results provide improved emission factor estimates across multiple conditions and can inform both prescribed fire management practices and the development of more representative emissions inventories. Full article

In January 2025, the Palisades and Eaton fires overtook large swaths of Los Angeles County, covering a combined area of approximately 152 km², composed of diverse coastal, urban, and forested environments. Aerial Light Detection and Ranging (LiDAR) surveys were commissioned directly following these fires, and compared against previously unreleased foundational LiDAR surveys captured in 2023 and 2024. The timeliness of these surveys presents a unique opportunity to approach large-scale damage characterization metrologically at sub-meter resolution. Cell-based height differencing across 367 million change-detected cells (on a 0.5 m grid) identifies 49.5 km² of vegetation loss and 1.66 km² of building footprint destruction in the Palisades fire, and 24.3 km² of vegetation loss and 1.48 km² of building footprint destruction in the Eaton fire. From the resulting volumetric loss inventory, we derive bottom-up carbon emission estimates of $255\pm 61$ kt C for the Palisades fire and $162\pm 38$ kt C for the Eaton fire. The Eaton estimate agrees to within 6% of an independent atmospheric inversion estimate derived from ground-based sensor networks, well within the propagated uncertainty of either method, providing an independent cross-validation, at the total-emission level, between LiDAR-based and atmospheric-inversion approaches to wildland–urban interface fire emissions. This paper details the segmentation and characterization methodology, and coincides with ALERTCalifornia’s public release of all described raw and derivative datasets. Full article

This work presents the design of a novel multi-component surface-coating system incorporating expandable graphite (EG), ammonium polyphosphate (APP), aluminium tri-hydroxide (ATH), alginate, and D-glucosamine hydrochloride (DGH). Importantly, the coated polyurethane (PU) foams demonstrated performance within the corresponding Hazard Level 3 limits for the measured parameters, including Maximum Average Rate of Heat Emission (MARHE), smoke density, and toxicity, providing preliminary indications of their potential for railway fire safety applications. Systematic variations in EG loading revealed substantial improvements in flammability metrics, with the EG-rich formulation achieving a limiting oxygen index (LOI) of 73%, MARHE of 18 kW m⁻², and significantly reduced smoke production. EG transformed the fire behaviour even at high external heat fluxes from flaming to self-extinguishing and only smouldering, promoting rapid formation of a dense, thermally insulating char. Combined interactions between EG, inorganic, and biobased additives reinforced char integrity, suppressed degradation rates, and enhanced condensed-phase protection. Thermogravimetric analysis confirmed increased residue yields (up to 52 weight percentage at 600 °C). Overall, this multi-functional coating offers a cost-effective, low-toxicity strategy for producing flame-resistant PU foams for demanding transportation and construction applications. Full article

The behavior of petroleum pool fires has important implications for fire safety and environmental protection due to heat release, smoke generation, and pollutant emissions. In this study, controlled pool-fire experiments were conducted using representative petroleum fuels with multiple pan diameters to investigate the coupled effects of fuel properties and geometric scale on combustion behavior and emission characteristics. Key parameters, including the heat release rate, smoke production rate, mass loss rate, major gaseous emissions, and soot characteristics, were systematically measured. The results show that increasing pan diameter accelerated fire development, increased combustion intensity, and generally enhanced cumulative gaseous emissions. Compared with kerosene, gasoline exhibited more rapid combustion and higher smoke production, whereas kerosene produced a more sustained heat-release process and higher cumulative gaseous emissions. Correlation analysis, principal component analysis, and principal component regression revealed that fuel thermophysical properties and geometric scale are the dominant factors governing combustion behavior and pollutant formation. The proposed statistical framework provides a practical approach for quantitatively relating fuel properties to heat-release characteristics. These findings improve the understanding of the coupled effects of fuel composition and fire scale on petroleum pool-fire behavior and provide experimental support for fire hazard assessment and combustion modeling. Full article

To address the challenge of balancing flame retardancy and dust suppression in conventional coal mine treatment materials, a multi-component synergistic flame-retardant dust-suppressant gel was fabricated using carboxymethyl cellulose (CMC) as the matrix, compounded with ammonium polyphosphate (APP), zinc borate (ZB), and polycarbodiimide (PCDI) as a cross-linking agent. The optimal formulation was determined via orthogonal experimental design combined with performance characterization, yielding a composition of 1 wt% CMC, 8 wt% APP, 2 wt% ZB, and 0.5 wt% PCDI. Systematic evaluations—including wettability tests, thermogravimetric analysis, and fire-extinguishing trials—demonstrated that the resultant CMC-based composite gel exhibits excellent structural stability and environmental tolerance. Specifically, the contact angle on the coal surface decreased sharply from 72.8° to 17.2°, and the mass loss rate after 30 min of wind erosion was merely 4.16%. Treatment with the gel elevated the critical temperature of the coal–oxygen reaction from 70 °C to 80 °C and reduced CO emissions by 40% at 170 °C. Furthermore, the temperatures corresponding to the maximum weight loss rate, ignition, and burnout increased by 12.9 °C, 16.8 °C, and 28.9 °C, respectively. Fire suppression tests revealed that the gel rapidly cools high-temperature coal seams and effectively prevents reignition. Mechanistic investigations indicate that the CMC-PCDI cross-linked network synergizes with the APP-ZB phosphorus–boron flame-retardant system: the three-dimensional gel architecture provides physical encapsulation and water retention, while the intumescent char layer formed by APP-ZB offers efficient oxygen barrier protection. This study provides a reliable gel-based technical solution for the integrated prevention and control of coal dust pollution and spontaneous combustion disasters in underground mines. Full article

Coal-fired power plants equipped with selective catalytic reduction (SCR) and wet flue-gas desulfurization (WFGD) can co-control mercury, but performance is limited by incomplete upstream Hg⁰ oxidation and downstream re-emission. This study evaluated a 660 MW unit using gas-, liquid-, and solid-phase measurements and coordinated single-factor and coupled operating tests. Under baseline conditions, SCR Hg⁰ oxidation was 31.66%, WFGD Hg²⁺ capture was 73.79%, and net mercury removal was 31.08%, with a stack Hg^T concentration of 4.70 µg/Nm³. Coupled optimization increased SCR Hg⁰ oxidation to 69.76% and WFGD Hg²⁺ capture to 96.05%, reduced the re-emission index from 0.596 to 0.250, and raised net removal to 70.83%. SCR inlet temperature, equivalent space velocity, and catalyst health were the dominant upstream factors, while S(IV), oxidation–reduction potential (ORP), slurry pH, and oxidation air supply governed downstream stabilization. A practical operating window was identified near 340 °C, with a normalized stoichiometric ratio (NSR) of approximately 1.0, high ammonia injection uniformity, pH of 5.5–6.0, ORP of approximately 200 mV, and S(IV) of approximately 2 mmol/L. The results show that coordinated operation of existing SCR–WFGD equipment can substantially reduce stack mercury without dedicated mercury-control hardware, provided that NH₃ slip, SO₃-related risk, catalyst condition, and absorber stability are simultaneously constrained. Full article

Coal fires are a significant source of greenhouse gas emissions and ecological pollutants, yet their emission characteristics and carbon accounting remain poorly constrained. To reveal the pollutant generation characteristics and carbon emission levels of the typical underground coal fire area in Sulabulak, Xinjiang, this study integrated laboratory simulation, multi-source remote sensing inversion, and in situ field monitoring. Thermogravimetric analysis, a high-temperature tube furnace, HSC thermodynamic simulation, and multi-source remote sensing data from Landsat-8/9 and Sentinel-1A were employed to investigate the gaseous products and heavy metal migration mechanisms at different combustion stages, and to delineate the spatial extent of different combustion states in the fire area. A coal loss model was then constructed by coupling experimentally determined carbon emission factors with remote sensing-derived areas and was compared with an emission flux model based on field measurements. The results show that the coal oxidation process proceeds through three distinct stages, with indicator gas ratios (CO₂/CO and C₂H₄/C₂H₆) serving as effective indicators for combustion state identification. Heavy metal partitioning is governed by elemental volatility and redox conditions: As and Se partition predominantly into the gas phase, while Zn becomes enriched in fly ash. Remote sensing time series analysis documents continuous fire expansion accompanied by progressive surface subsidence. By cross-validating the indirect coal loss model (constrained by remote sensing area) against the direct emission flux model (constrained by field measurements), we estimate the current annual GHG emission of the Sulabulak fire area at approximately 0.65 × 10⁴ t CO₂ equivalent. This study proposes a coupled “micro-experiment–macro-remote sensing–field measurement” approach for carbon emission accounting, providing reliable data support for environmental pollution control and the development of carbon inventories for coal fires in arid regions. Full article

We present FDS and AERMOD simulations of the Alaska Clean Seas (ACS) oil burn experiments to improve dispersion modeling of large, open-air fires relevant to industrial settings. We propose a method in which FDS smoke fields with available ground measurements are used to empirically calibrate AERMOD configured using volume sources to represent the fire source. FDS is first run for the three ACS experiments at high resolutions (~10 m) and verified against ground monitoring to provide detailed three-dimensional smoke fields. The fractional allocation of total fire emissions (weights, w_i) is then empirically specified for each volume source i so AERMOD smoke predictions fit both the ground level measurements and FDS simulations to acceptable accuracy. Runs for volumes at the surface (i = 1), 100 m AGL (i = 2) and 300 AGL (i = 3) and w_i = [0.01, 0.09, 0.9]–[0.04, 0.36, 0.6] accurately represent these data, suggesting this range as suitable for fire heat fluxes (~800–3000 kW/m²), wind speeds (5–10 m/s) and PBL depths (300–500 m with and without capping temperature inversions) of the three ACS experimental burns. Further work exploring the applicability of this AERMOD setup to a broader range of conditions is ongoing. Full article

In the context of the new power system, coal-fired units are transitioning into peaking units. This study investigates the combustion characteristics and NO_X emissions of a 600 MW opposed wall-fired boiler within a load range of 50% to 20%, and further analyzes the impact of burner operation modes on boiler performance at the 20% ultra-low load. The results indicate that as the boiler load decreases from 50% to 20%, the average temperature in the primary combustion zone drops from 1634.3 K to 1457.0 K, and the ignition distance extends from 0.228 m to 0.260 m, leading to a significant decline in combustion stability. Notably, at the 20% ultra-low load, although the drop in temperature suppresses the formation of thermal NO_X, the flow short-circuiting caused by the shrinking of the recirculation zone results in pulverized coal particles missing the optimal reduction window; the formation pathway dominated by fuel NO_X causes the NO_X concentration at the furnace outlet to surge to 670.6 mg/m³. Furthermore, the burner operation modes significantly influence boiler performance at the 20% ultra-low load. While ensuring combustion stability, operating the lower-tier burners effectively reduces NO_X emissions by up to 21.6%. Considering both combustion stability and NO_X emissions, prioritizing the operation of lower-tier burners is recommended. This study reveals the underlying mechanisms behind the surge in NO_X concentrations at ultra-low loads of 20% and proposes optimal burner operation strategies, providing a theoretical foundation for the clean and stable operation of boilers during deep peak shaving. Full article

Distributed photovoltaic (PV) systems are increasingly important for renewable-energy transformation, prosumer participation, and low-emission electricity markets. However, failures affecting inverters, DC-side components, connectors, protection devices, monitoring units, and PV modules may reduce generation continuity, increase service burden, and weaken user confidence in distributed generation. Previous PV-failure studies have mainly identified failure modes or ranked them according to maintenance priority, whereas service companies require actionable classes linked with inspection intervals and corrective actions. This study develops and empirically applies a Delphi-based dimension-adjusted fuzzy SIWEC-MABAC decision-support framework for classifying PV installation failures into maintenance action classes. The procedure combines a completed three-round Delphi expert panel, linguistic uncertainty modelling using dimension-adjusted fuzzy sets, SIWEC criterion weighting, and MABAC ranking based on distance from the border approximation area. The empirical SIWEC–MABAC results show that safety/fire impact, downtime duration, and detectability difficulty dominate the service classification. Arc-fault-related DC-side damage and cable insulation degradation are assigned to immediate corrective action, whereas junction-box overheating, inverter hardware failure, melted MC4 connectors, hot-spot formation, and DC circuit-breaker failure require short-term preventive inspection. The validated framework supports service triage and inspection scheduling rather than real-time fault detection. A one-dimensional four-cluster check reproduced the same class membership, and TOPSIS cross-validation showed strong rank agreement with MABAC (Spearman rho = 0.951). Full article

This paper presents a detailed analysis of the operating parameters of a solar active installation with seven photovoltaic-thermal (PV/T) collectors with a total area of 14 m² in a single-family house. A comparative analysis of the work parameters was carried out for the following two locations: Warsaw (Poland) and Andravida (Greece), based on the research of the solar system model created in the TRNSYS 16 program. Considering the months with the best sunshine, from May to August, the average monthly electricity yield in PV/T solar collectors was 206 kWh (Warsaw) and 248 kWh (Andravida). In July, the monthly generation-to-consumption ratio of the PV/T system under the Polish climate conditions was 82%, and under the Greek climate conditions—99%. The heat recovery from PV/T solar collectors in July in the climate of Greece was estimated at 264 kWh and is 29% higher compared to the heat recovery in a hybrid solar installation located in Poland. The generation of electricity in the PV/T solar system instead of a coal-fired power plant can contribute to the avoidance of the annual emissions of pollutants by: 14.00–19.11 kg of SO₂, 2.72–3.72 kg of NO_X, 5.44–7.43 kg of CO, 1330.86–1816.79 kg of CO₂, and 1.09–1.49 kg of particulate matter, depending on the location. Full article

In response to the significant seasonal fluctuations in heating and cooling loads in greenhouses for high-value fruit trees in northern China, as well as issues such as heat accumulation on the ground-source side and high carbon emissions from coal-fired heating, this paper proposes a coupled energy supply system comprising a PVT system, a mine pit seasonal thermal storage unit, a ground-source heat pump and a cooling tower. Taking a 30,000 m² cherry greenhouse and an existing 15,000 m³ mine pit thermal storage reservoir in Weifang, Shandong Province, as the research objects, annual design-stage simulations with a 0.125 h time step were conducted using SketchUp-TRNBuild and TRNSYS. Discrete sensitivity analyses and engineering constraints were used to determine the PVT area and cooling tower outlet temperature. Heating demand mainly occurred from November to February, whereas cooling demand was concentrated from June to September. The selected 2452 m² PVT system supplied direct heating for 34 days, covered 23.05% of the seasonal heating demand, and achieved a storage efficiency of 69.17%. Without a cooling tower, the first-year soil temperature increased by 1.1 °C. With a 26 °C cooling tower outlet temperature, the soil thermal imbalance ratio decreased to 2.4%, and the 15-year soil temperature rise was limited to 0.28 °C. The recommended system required 1.3239 million kWh of net purchased electricity annually, reduced operating costs by approximately CNY 802,800 (USD 118,243) and operational emissions by 2027.8 tCO₂-eq per year relative to the baseline, and had a static payback period of 6.4 years. The annual operational emission reduction was linearly extrapolated over a 20-year assessment period under fixed weather, load, equipment performance, and grid emission assumptions, resulting in a scenario-based carbon reduction threshold of 40,556 tCO₂-eq. Net life cycle carbon savings would be possible if the additional emissions from construction, equipment replacement, and end-of-life treatment remained below this threshold. Full article