Search Results (201)

Based on the low-carbon transition needs of coal-fired boilers, this study conducted industrial trials of direct biomass co-firing on a 620 t/h high-temperature, high-pressure circulating fluidized bed (CFB) boiler, gradually increasing the co-firing ratio. It used compressed biomass pellets, achieving stable 20 wt% (weight percent) operation. By analyzing boiler parameters and post-shutdown samples, the comprehensive impact of biomass co-firing on the boiler system was assessed. The results indicate that biomass pellets were blended with coal at the last conveyor belt section before the furnace, successfully ensuring operational continuity during co-firing. Further, co-firing biomass up rates of to 20 wt% do not significantly impact the fuel combustion efficiency (gaseous and solid phases) or boiler thermal efficiency and also have positive effects in reducing the bottom ash and SO_x and NO_x emissions and lowering the risk of low-temperature corrosion. The biomass co-firing slightly increases the combustion share in the dense phase zone and raises the bed temperature. The strong ash adhesion characteristics of the biomass were observed, which were overcome by increasing the ash blowing frequency. Under 20 wt% co-firing, the annual CO₂ emissions reductions can reach 130,000 tons. This study provides technical references and practical experience for the engineering application of direct biomass co-firing in industrial-scale CFB boilers. Full article

A simple and fast analytical method was developed and applied to assess the effect of two forms of zinc fertilization on a pecan tree cultivar in Uruguay: fertigation and foliar application with a specially formulated fertilizer. Zinc content was determined in 36 leaf samples from two crop cycles: 2020–2021 and 2021–2022. Fresh samples were dried, ground, and sieved. Analytical determinations were performed by flame atomic absorption spectrometry (FAAS, considered a standard method) and energy dispersive X-ray spectrometry (EDXRF, the proposed method). In the first case, sample preparation was carried out by microwave-assisted digestion using 4.5 mol L⁻¹ HNO₃. In the second case, pellets (Φ 13 mm, 2–3 mm thick) were prepared by direct mechanical pressing. Figures of merit of both methodologies were adequate for the purpose of zinc monitoring. The results obtained from both methodologies were statistically compared and found to be equivalent (95% confidence level). Based on the principles of Green Analytical Chemistry, both procedures were evaluated using the Analytical Greenness Metric Approach (AGREE and AGREEprep) tools. It was concluded that EDXRF was notably greener than FAAS and can be postulated as an alternative to the standard method. The information emerging from the analyses aided decision-making at the agronomic level. Full article

The combustion of fossil fuels is a major source of greenhouse gas emissions, drives climate change, and has intensified the search for cleaner energy alternatives such as biomass. Biomass derived from renewable organic materials, is considered a sustainable and carbon-neutral energy source. While biomass represents a renewable and clean energy source, its combustion, especially in pellet form, can produce various pollutants such as CO₂, SO₂, NO₂, CO, and PM. This study focuses on analyzing the combustion of six different pellet brands and the emissions they produce. A dedicated experimental procedure was designed and implemented to evaluate the combustion performance. The temperature shows a gradual increase in ambient temperature around 2.5 °C across all tests, with a similar behavior, the temperature of flue gas shows a similar behavior between tests with temperatures peaking around 300 °C and 340 °C. In the tests conducted, all pellets complied with the legal emission limits defined by legislation. The efficiency calculated using the direct method was lower by around 55%, primarily due to the use of an older boiler (manufactured in 2004) and short duration of the test. The indirect method shows better efficiency, around 70%, influenced by lower moisture content of the pellets. The results indicate that B pellets had a superior performance compared to the others evaluated. Full article

The increasing accumulation of plastic waste—especially from packaging and post-consumer sources—calls for the development of sustainable recycling strategies. Due to the challenges associated with sorting mixed waste, directly processing waste streams offers a practical approach. Polyethylene terephthalate (PET) and high-density polyethylene (HDPE) are common consumer plastics, but they are difficult to recycle together due to immiscibility and degradation. In mixed waste, recycled HDPE (r-HDPE) often contaminates the recycled PET (r-PET) stream. Additive manufacturing (AM) offers a promising solution to upcycle these mixed polymers into functional products with minimal waste. This study investigates the processing and characterization of r-PET/r-HDPE blends for AM, focusing on the role of compatibilizers in enhancing their properties. Blends were melt-compounded using a twin-screw extruder to improve dispersion, followed by direct pellet-based 3D printing. A compatibilizer (0–7 php) was incorporated to improve miscibility. Rheological testing showed that the 5 php compatibilizer optimized viscosity and elasticity, ensuring smoother extrusion. Thermal analysis revealed a 30 °C increase in crystallization temperature and a shift in decomposition temperature from 370 °C to 400 °C, indicating improved thermal stability. Mechanical testing showed a tensile strength of 35 MPa and 17% elongation at break at optimal loading. Scanning electron microscopy (SEM) confirmed reduced phase separation and improved morphology. This work demonstrates that properly compatibilized r-PET/r-HDPE blends enable sustainable 3D printing without requiring polymer separation. The results highlight a viable path for the conversion of plastic waste into high-value, customizable components, contributing to landfill reduction and advancing circular economy practices in polymer manufacturing. Full article

Amid escalating global climate crises and the urgent imperative to meet the Paris Agreement’s carbon neutrality targets, the steel industry—a leading contributor to global greenhouse gas emissions—confronts unprecedented challenges in driving sustainable industrial transformation through innovative low-carbon steelmaking technologies. This paper examines decarbonization technologies across three stages (source, process, and end-of-pipe) for two dominant steel production routes: the long process (BF-BOF) and the short process (EAF). For the BF-BOF route, carbon reduction at the source stage is achieved through high-proportion pellet charging in the blast furnace and high scrap ratio utilization; at the process stage, carbon control is optimized via bottom-blowing O₂-CO₂-CaO composite injection in the converter; and at the end-of-pipe stage, CO₂ recycling and carbon capture are employed to achieve deep decarbonization. In contrast, the EAF route establishes a low-carbon production system by relying on green and efficient electric arc furnaces and hydrogen-based shaft furnaces. At the source stage, energy consumption is reduced through the use of green electricity and advanced equipment; during the process stage, precision smelting is realized through intelligent control systems; and at the end-of-pipe stage, a closed-loop is achieved by combining cascade waste heat recovery and steel slag resource utilization. Across both process routes, hydrogen-based direct reduction and green power-driven EAF technology demonstrate significant emission reduction potential, providing key technical support for the low-carbon transformation of the steel industry. Comparative analysis of industrial applications reveals varying emission reduction efficiencies, economic viability, and implementation challenges across different technical pathways. The study concludes that deep decarbonization of the steel industry requires coordinated policy incentives, technological innovation, and industrial chain collaboration. Accelerating large-scale adoption of low-carbon metallurgical technologies through these synergistic efforts will drive the global steel sector toward sustainable development goals. This study provides a systematic evaluation of current low-carbon steelmaking technologies and outlines practical implementation strategies, contributing to the industry’s decarbonization efforts. Full article

Improving the manufacturability of drug formulations via direct compression has been of great interest for the pharmaceutical industry. Selecting excipients plays a vital role in obtaining a high-quality product without the wet granulation processing step. In particular, for diluents which are usually present in a larger amount in a formulation, choosing the correct one is of utmost importance in the production of tablets via any method. In this work, we assessed the possibility of manufacturing a small-molecule drug product, omeprazole, which has been historically manufactured via a multi-step processes such as wet granulation and multiple-unit pellet system (MUPS). For this purpose, four prototypes were developed using several diluents: a co-processed excipient (Microcelac^®), two granulated forms of alpha-lactose monohydrate (Tablettose^® 70 and Tabletose^® 100), and a preparation of microcrystalline cellulose (Avicel^® PH102) and lactose (DuraLac^® H), both of which are common excipients without any enhancement. The tablets were produced using a single punch tablet press and thoroughly characterized physically and chemically in order to assess their functionality and adherence to drug product specifications. The direct compression process was used for the manufacturing of all proposed formulations, and the prototype formulated using Microcelac^® showed the best results and performance during the compression process. In addition, it remained stable over twelve months under 25 °C/60% RH conditions. Full article

The iron and steel industry, as a major energy consumer, was critically required to enhance operational efficiency and reduce CO₂ emissions. Conventional blast furnace processing of vanadium–titanium magnetite (VTM) in China had been associated with persistent challenges, including suboptimal TiO₂ recovery rates (<50%) and elevated carbon intensity (the optimal temperature range for TiO₂ recovery lies within 1400–1500 °C). Shaft furnace technology has emerged as a low-carbon alternative, offering accelerated reduction kinetics, operational flexibility, and reduced environmental impact. This study evaluated the low-carbon PLCsmelt process for VTM smelting through energy–mass balance modeling, comparing two gas-recycling configurations. The process integrates a pre-reduction shaft furnace and a melting furnace, where oxidized pellets are initially reduced to direct reduced iron (DRI) before being smelted into hot metal. In Route 1, CO₂ emissions of 472.59 Nm³/tHM were generated by pre-reduction gas (1600 Nm³/tHM, 64.73% CO, and 27.17% CO₂) and melting furnace top gas (93.98% CO). Route 2 incorporated hydrogen-rich gas through the blending of coke oven gas with recycled streams, achieving a 56.8% reduction in CO₂ emissions (204.20 Nm³/tHM) and altering the pre-reduction top gas composition to 24.88% CO and 40.30% H₂. Elevating the pre-reduction gas flow in Route 2 resulted in increased CO concentrations in the reducing gas (34.56% to 37.47%) and top gas (21.89% to 26.49%), while gas distribution rebalancing reduced melting furnace top gas flow from 261.03 to 221.93 Nm³/tHM. The results demonstrated that the PLCsmelt process significantly lowered carbon emissions without compromising metallurgical efficiency (CO₂ decreased about 74.48% compared with traditional blast furnace which was 800 Nm³/tHM), offering a viable pathway for sustainable VTM utilization. Full article

Goal-directed reaching movements are extremely accurate to the point that the location, placement, and speed of the limbs are specific from trial to trial. These movements require descending motor commands and feedback modulation from ascending sensory information. The descending motor commands and ascending sensory information work in conjunction to ensure that the movement is accurate and precise through an error-corrected process that resides in the cerebellum. Disruptions to this information may cause errors in the precision of forelimb motor targeting. According to the previous literature, the external cuneate nucleus (ECN) and central cervical nucleus (CeCv) are responsible for conveying unconscious sensory information from the forelimbs, shoulders, and neck muscles to the cerebellum. Here, we examined the significance of the ECN and CeCv, separately, in forelimb function. In conjunction with inhibitory DREADDs (hM4Di), we observed an obstruction in single pellet reaching and grasping when ECN activity was repressed, both unilaterally and bilaterally, in normal rats. We also observed reduced reach in the grooming assessment bilaterally. We discovered that the CeCv terminates in the medial cerebellar nucleus (MCN), within the deep cerebellar nuclei (DCN), which, to the best of our knowledge, was previously not clearly defined. Together, this information provides evidence that the requirement of ascending sensory information is important in forelimb function. Full article

In the context of the “carbon peaking and carbon neutrality” era, China’s steel industry, as one of the pillars of the national economy, must accelerate the exploration and adoption of innovative production processes to effectively reduce its carbon footprint. The numerical simulation of hydrogen-based shaft furnaces is an important method for studying the internal characteristics of steelmaking processes. Its objective is to set reasonable furnace parameters to significantly enhance production efficiency and environmental friendliness, ensuring that sustainability and economic benefits coexist in the steel manufacturing process. In order to develop a new shaft furnace, which simplifies the cooling parts, the mathematical model was used to conduct a numerical simulation analysis of hydrogen-based shaft furnaces. The Discrete Element Method (DEM) was employed to focus on the stress and wear behavior of internal components within the hydrogen-based shaft furnace. The results indicated that during the charging of iron ore pellets, the outlet area experienced friction and compression from Direct Reduced Iron (DRI), resulting in a maximum stress of 47,422.1 Pa at the output section. The stresses on the loosening roller were locally concentrated due to its clockwise rotational motion, with a maximum shear stress of 219,896.1 Pa. By applying the Archard wear theory and the moving bed model, the theoretical wear degrees of the refractory materials in the reduction section and the steel shell in the cooling section were obtained; the monthly wear rate of the loosening roller was approximately 0.601 mm. Reasonably setting the parameters and feeding speed of the hydrogen-based shaft furnace can optimize the force and wear conditions of internal components, achieving optimal operating conditions. This provides a reference for factories to effectively extend the service life of hydrogen-based shaft furnaces and offers reasonable suggestions for the future industrial application of hydrogen metallurgy. Full article

Methanol synthesis can utilize the product gas from biomass gasification and the hydrogen generated from water electrolysis. Biomass gasification, as an upstream process, affects the subsequent hydrogen supplement amount and has a direct relationship with the methanol yield. Fluidized bed oxygen-enriched gasification has a particular advantage for biomass and is expected to utilize the remaining oxygen from water electrolysis. In this study, the effects of operating parameters, including the equivalence ratio ER, temperature T, oxygen percentage OP in oxygen-enriched air, steam-to-wood pellets mass ratio S/W, and fluidization velocity u_g, as well as the choice of bed materials, on the volume fractions of the gas products and the gas yield from the fluidized bed oxygen-enriched gasification of wood pellets were investigated. The effects of the generation characteristics of gas products on the hydrogen supplement amount and the methanol yield were also analyzed. The results showed that the volume fraction of H₂ reached its peak values of 10.47% and 18.49% at an ER value of 0.28 and a u_g value of 0.187 m/s, respectively. The methanol yield reached its peak value of 0.54 kg/kg at a u_g value of 0.155 m/s. The volume fraction of H₂ increased from 6.13% to 11.74% with an increasing temperature from 650 °C to 850 °C, increased from 5.72% to 10.77% with an increasing OP value from 21% to 35%, and increased from 12.39% to 19.06% with an increasing S/W value from 0.16 to 0.38. The methanol yield could be improved by increasing the ER value, T value, OP value, or S/W value. When the bed materials were changed from quartz sands to dolomite granules, the H₂ volume fraction significantly increased and the hydrogen supplement amount required for methanol synthesis reduced. Full article

Iron smelting is one of the primary sources of carbon emissions. The development of low-carbon ironmaking technologies is essential for the iron and steel industry to realize the “dual carbon” ambition. Hydrogen-based flash ironmaking technology eliminates traditional pretreatment steps such as sintering, pelletizing, and coking while using hydrogen as a reducing agent, significantly reducing carbon emissions. In the present work, a computational fluid dynamics approach is employed to conduct an in-depth analysis of the radiative properties inside the reaction shaft of a flash smelting furnace. The results illustrate that the lowest gas absorption coefficient and volumetric absorption radiation along the radial direction appear at y = 2.84 m, with the values of 0.085 m⁻¹ and 89,364.6 W/m³, respectively, whereas the largest values for these two variables in the axial direction can be obtained at h = 6.14 m with values of 0.128 m⁻¹ and 132,841.11 W/m³. The reduced incident radiation intensity under case 1’s condition led to distinct differences in the radiative temperature compared to the other four cases. The spatial distributions of the particle absorption and scattering coefficients exhibit excellent consistency. The thermal conductivities of all investigated cases depict similar trends along both the axial and radial directions. Volumetric emissive radiation presents a non-linear trend of first increasing and then decreasing, followed by the rise as the height decreases. This study highlights the critical role of hydrogen-based flash ironmaking technology in reducing carbon emissions and provides valuable insights into the radiative characteristics of its reaction shaft under different operating conditions. Full article

In the rim zone of UO₂ nuclear fuel pellets, high burn-up and low temperatures drive changes in the microstructure, leading to the formation of high burn-up structures (HBS). This review focuses on the formation of HBS, beginning with a description of the two contentious mechanisms—recrystallization and polygonization—that are believed to be the primary controlling factors. We discuss experimental and simulation studies that support both mechanisms, emphasizing that although each mechanism can explain certain aspects of HBS formation, neither recrystallization nor polygonization alone is sufficient to fully explain the observed phenomena. Furthermore, we emphasize the intrinsic relationship between these two mechanisms, suggesting that they represent different manifestations of the same underlying process under varying conditions, and we reference relevant studies that support this perspective. Lastly, we underline the significance of investigating the formation processes of HBS and provide an outlook on future research directions based on the current state of knowledge. Full article

Systemic fluorescence tracers introduced into crop plants provide an active signal for crop–weed differentiation that can be exploited for precision weed management. Rhodamine B (RB), a widely used tracer for seeds and seedlings, possesses desirable properties; however, its application as a seed treatment has been limited due to potential phytotoxic effects on seedling growth. Therefore, investigating mitigation strategies or alternative systemic tracers is necessary to fully leverage active signaling for crop–weed differentiation. This study aimed to identify and address the phytotoxicity concerns associated with Rhodamine B and evaluate Rhodamine WT and Sulforhodamine B as potential alternatives. A custom 2D fluorescence imaging system, along with analytical methods, was developed to optimize fluorescence imaging quality and facilitate quantitative characterization of fluorescence intensity and patterns in plant seedlings, individual leaves, and leaf disc samples. Rhodamine compounds were applied as seed treatments or in-furrow (soil application). Rhodamine B phytotoxicity was mitigated by growing in a sand and perlite media due to the adsorption of RB to perlite. Additionally, in-furrow and seed treatment methods were tested for Rhodamine WT and Sulforhodamine B to evaluate their efficacy as non-phytotoxic alternatives. Experimental results demonstrated that Rhodamine B applied via seed pelleting and Rhodamine WT used as a direct seed treatment were the most effective approaches. A case study was conducted to assess fluorescence signal intensity for crop–weed differentiation at a crop–weed seed distance of 2.5 cm (1 inch). Results indicated that fluorescence from both Rhodamine B via seed pelleting and Rhodamine WT as seed treatment was clearly detected in plant tissues and was ~10× higher than that from neighboring weed plant tissues. These findings suggest that RB ap-plied via seed pelleting effectively differentiates plant seedlings from weeds with reduced phytotoxicity, while Rhodamine WT as seed treatment offers a viable, non-phytotoxic alternative. In conclusion, the combination of the developed fluorescence imaging system and RB seed pelleting presents a promising technology for crop–weed differentiation and precision weed management. Additionally, Rhodamine WT, when used as a seed treatment, provides satisfactory efficacy as a non-phytotoxic alternative, further expanding the options for fluorescence-based crop–weed differentiation in weed management. Full article

Seed enhancements involve post-harvest modifications that improve germination and plant performance. One form of enhancement involves coatings, which encompasses encrusting, pelleting, and film coats. These coatings may contain agrichemicals, such as fungicides and insecticides, and can foster conformational changes that improve the plantability of small or irregularly shaped seeds. Seed encapsulation using pharmaceutical capsules can be viewed as an extension of seed coatings where seeds and other beneficial agrichemicals can be combined into a single plantable unit. For many crops, direct contact with high levels of conventional fertilizers may induce some level of phytotoxicity, and early studies involving fertilizer-enriched seed coatings resulted in decreased seedling emergence and diminished plant performance. Encapsulation, however, provides greater delivery volumes compared to other coatings and may offer some degree of separation between seeds and potentially phytotoxic agrochemicals. This study considered tomato seed encapsulation with controlled-release fertilizers. In general, seed exposure to gelatin-based capsules delayed germination by 2- to 3- days. Nevertheless, seed encapsulation improved plant performance including increased plant height and dry mass production by as much as 75 and 460%, respectively. These growth responses mitigated any effects attributed to germination delays. Moreover, higher levels of controlled-release fertilizers (≥800 mg) fostered earlier flower induction by up to 3 weeks. Collectively, the results suggest that seed encapsulation can be an effective way to deliver fertilizers to plants in a manner that could reduce overall fertilizer application rates and possibly lessen the quantity of plant nutrient input necessary for tomato cultivation. Full article

This work conducts a single-factor experiment to study the effects of biomass types on the relax density, volume expansion, durability, hydrophobicity, and processing energy consumption. We analyze the differences in the quality of the pellets, and optimize the compaction conditions suitable for different biomass types including straw, hardwood, shell, and herbaceous plant. The results indicated that with a compressing force of 60~1500 N, compressing time of 10 s, powder size of less than 0.5 mm, and moisture content of 10%, the relax densities of corn straw, rice straw, selenium-rich rice straw, weigela japonica branches, and camphor leaves range from 360 to 820 kg/m³, with a processing energy consumption of 17,360 to 28,740 J/kg; meanwhile, the relax densities of argy wormwood, forage grass, green grass, and peanut shells range from 340 to 840 kg/m³, with a processing energy consumption of 33,510 to 73,700 J/kg. Therefore, the compaction pretreatment effectively regulates the density of biomass pellets and reduces the processing energy consumption. This study analyzed the differences in the quality of pellets caused by the inherent characteristics of biomass, providing strong support for the directional depolymerization and enhanced pretreatment technology for the scaled production of biomass alcohol fuels. Full article