Search Results (171)

Actions related to reducing CO₂ emissions have led to the development of technologies using raw materials in the form of broadly understood biomass as CO₂-neutral fuels. There has been a rapid development of pyrolysis processes (carbonization, dry distillation) of various types of biomass toward the production of biochar for industrial applications. Particularly high hopes are associated with the use of biochar as a substitute for fossil fuel in energy-intensive sectors of the economy, especially the metallurgical and steel industries. This paper characterizes the current state and potential for biochar application, using the iron and steel industry as a case study. The analysis focuses primarily on the characteristics of biochar production and its industrial application potential. The characterization includes the diversity of biomass feedstocks, processing methods, and reactor types, the influence of operational parameters on biochar yield, as well as the properties and applications of biochar. As part of the analysis of biomass use potential in the iron and steel industry, the study reviews the current levels of coal substitution achieved at the laboratory scale and presents examples of biochar implementation in existing industrial facilities. In addition, key factors limiting the feasibility of coal substitution in the iron and steel industry are identified. The summary includes the main directions for further research aimed at increasing the use of biochar in industry. Full article

Given the increasing volume of selectively collected bio-waste and the requirement to increase waste treatment system energy efficiency, dry anaerobic digestion (DAD) represents a more sustainable choice for the treatment of municipal organic fraction instead of conventional technologies. The current paper provides an overview of the existing knowledge on DAD of green waste or kitchen waste collected selectively. Key substrates characteristics (chemical composition, methane potential), novel reactor design and process conditions relevant to effective digestion at elevated dry matter content are considered. Of special interest is the process intensification techniques, impact of contamination and co-fermentation opportunity with other biodegradable wastes. This article also discusses energy and economic performance of DAD plants and puts their environmental burden in perspective versus other bio-waste treatment processes. The current legislation and DAD’s role in the circular economy are also considered. Selectively collected biowaste has significant energy potential and dry anaerobic digestion is an effective technology, especially in areas with limited water availability, offering both waste volume reduction and minimized energy losses. The aim of this work is to introduce the potential of this technology as a sustainable option within the context of renewable energy and modern waste management. Full article

The political commitment to reaching carbon-free energy generation by the year 2050 has led to an increased expansion of renewable energy power plants. As renewable energy generation is intermittent and current energy storage options are limited, a diversified energy grid including nuclear power is the preferable choice for most nations. Many innovative reactor concepts are being pursued in research and development, aiming to supplement fluctuating energy sources. However, it is yet unclear if these technologies can be economically deployed in time. This paper presents the current political views and events concerning the global expansion of nuclear energy, focusing on Europe and the USA. Further, the most important safety aspects of large nuclear power plants are discussed. Moreover, knowledge and definition gaps regarding the applicability of established procedures for innovative reactor concepts are included. The authors highlight that advanced manufacturing techniques play a key role in the economic and technical realization of innovative reactor concepts. The present work is intended to provide insight into current developments in nuclear technology while providing more detail on safety aspects and innovative manufacturing methods. Full article

High-resistance faults on the DC lines of multi-terminal VSC-HVDC grids lead to insufficient protection reliability, and the introduction of current-limiting strategies alters the system’s intrinsic fault characteristics, degrading protection performance. To address these issues, we propose a DC-line protection scheme that is immune to converter control strategies and highly tolerant to fault resistance. First, based on the grid topology, post-fault current paths are analyzed, and the fault characteristics produced solely by the fault-induced voltage source are identified. A sequential overlapping derivative transformation is then employed to magnify the discrepancy between internal and external faults, forming the core of the fault-identification criterion; the zero-mode component is used for pole selection. Finally, a four-terminal VSC-HVDC model is built in PSCAD/EMTDC version 4.6.2 for validation. Simulation results show that, after applying the current-limiting strategy, the characteristic quantity changes only marginally, and the proposed protection can reliably withstand fault resistances of up to 700 Ω. Full article

Endotoxins, lipopolysaccharides released from the outer membrane of Gram-negative bacteria, pose a significant risk in healthcare environments, particularly in Central Sterile Supply Departments (CSSDs), where the delivery of sterile pyrogen-free medical devices is critical for patient safety. Traditional methods for controlling endotoxins in water systems, such as ultraviolet (UV) disinfection, have proven ineffective at reducing endotoxin concentrations to comply with regulatory standards (<0.25 EU/mL). This limitation presents a significant challenge, especially in the context of reverse osmosis (RO) permeate used in CSSDs, where water typically has very low conductivity. Despite the established importance of endotoxin removal, a gap in the literature exists regarding effective chemical-free methods that can meet the stringent endotoxin limits in such low-conductivity environments. This study addresses this gap by evaluating the effectiveness of the eBooster™ electrochemical technology—featuring proprietary electrode materials and a reactor design optimized for potable water—for endotoxin removal from water, specifically under the low-conductivity conditions typical of RO permeate. Laboratory experiments using the B250 reactor achieved >90% endotoxin reduction (from 1.2 EU/mL to <0.1 EU/mL) at flow rates ≤5 L/min and current densities of 0.45–2.7 mA/cm². Additional real-world testing at three hospitals showed that the eBooster™ unit, when installed in the RO tank recirculation loop, consistently reduced endotoxin levels from 0.76 EU/mL (with UV) to <0.05 EU/mL over 24 months of operation, while heterotrophic plate counts dropped from 190 to <1 CFU/100 mL. Statistical analysis confirmed the reproducibility and flow-rate dependence of the removal efficiency. Limitations observed included reduced efficacy at higher flow rates, the need for sufficient residence time, and a temporary performance decline after two years due to a power fault, which was promptly corrected. Compared to earlier approaches, eBooster™ demonstrated superior performance in low-conductivity environments without added chemicals or significant maintenance. These findings highlight the strength and novelty of eBooster™ as a reliable, chemical-free, and maintenance-friendly alternative to traditional UV disinfection systems, offering a promising solution for critical water treatment applications in healthcare environments. Full article

This study proposes the SMR Smart Net-Zero City (SSNC) framework—a scalable model for achieving carbon neutrality by integrating Small Modular Reactors (SMRs), renewable energy sources, and sector coupling within a microgrid architecture. As deploying renewables alone would require economically and technically impractical energy storage systems, SMRs provide a reliable and flexible baseload power source. Sector coupling systems—such as hydrogen production and heat generation—enhance grid stability by absorbing surplus energy and supporting the decarbonization of non-electric sectors. The core contribution of this study lies in its real-time data emulation framework, which overcomes a critical limitation in the current energy landscape: the absence of operational data for future technologies such as SMRs and their coupled hydrogen production systems. As these technologies are still in the pre-commercial stage, direct physical integration and validation are not yet feasible. To address this, the researchers leveraged real-time data from an existing commercial microgrid, specifically focusing on the import of grid electricity during energy shortfalls and export during solar surpluses. These patterns were repurposed to simulate the real-time operational behavior of future SMRs (ProxySMR) and sector coupling loads. This physically grounded simulation approach enables high-fidelity approximation of unavailable technologies and introduces a novel methodology to characterize their dynamic response within operational contexts. A key element of the SSNC control logic is a day–night strategy: maximum SMR output and minimal hydrogen production at night, and minimal SMR output with maximum hydrogen production during the day—balancing supply and demand while maintaining high SMR utilization for economic efficiency. The SSNC testbed was validated through a seven-day continuous operation in Busan, demonstrating stable performance and approximately 75% SMR utilization, thereby supporting the feasibility of this proxy-based method. Importantly, to the best of our knowledge, this study represents the first publicly reported attempt to emulate the real-time dynamics of a net-zero city concept based on not-yet-commercial SMRs and sector coupling systems using live operational data. This simulation-based framework offers a forward-looking, data-driven pathway to inform the development and control of next-generation carbon-neutral energy systems. Full article

Since the initial use of biological ion channels to detect single-stranded genomic base pair differences, label-free and highly sensitive resistive pulse sensing (RPS) with nanopores has made remarkable progress in single-molecule analysis. By monitoring transient ionic current disruptions caused by molecules translocating through a nanopore, this technology offers detailed insights into the structure, charge, and dynamics of the analytes. In this work, the RPS platforms based on biological, solid-state, and other sensing pores, detailing their latest research progress and applications, are reviewed. Their core capability is the high-precision characterization of tiny particles, ions, and nucleotides, which are widely used in biomedicine, clinical diagnosis, and environmental monitoring. However, current RPS methods involve bottlenecks, including limited sensitivity (weak signals from sub-nanometer targets with low SNR), complex sample interference (high false positives from ionic strength, etc.), and field consistency (solid-state channel drift, short-lived bio-pores failing POCT needs). To overcome this, bio-solid-state fusion channels, in-well reactors, deep learning models, and transfer learning provide various options. Evolving into an intelligent sensing ecosystem, RPS is expected to become a universal platform linking basic research, precision medicine, and on-site rapid detection. Full article

This study developed a two-dimensional multiphysics-coupled model for co-electrolysis of CO₂ and H₂O in solid oxide electrolysis cells (SOECs) using COMSOL Multiphysics, systematically investigating the influence mechanisms of key operating parameters including temperature, voltage, feed ratio, and flow configuration on co-electrolysis performance. The results demonstrate that increasing temperature significantly enhances CO₂ electrolysis, with the current density increasing over 12-fold when temperature rises from 923 K to 1423 K. However, the H₂O electrolysis reaction slows beyond 1173 K due to kinetic limitations, leading to reduced H₂ selectivity. Higher voltages simultaneously accelerate all electrochemical reactions, with CO and H₂ production at 1.5 V increasing by 15-fold and 13-fold, respectively, compared to 0.8 V, while the water–gas shift reaction rate rises to 6.59 mol/m³·s. Feed ratio experiments show that increasing CO₂ concentration boosts CO yield by 5.7 times but suppresses H₂ generation. Notably, counter-current operation optimizes reactant concentration distribution, increasing H₂ and CO production by 2.49% and 2.3%, respectively, compared to co-current mode, providing critical guidance for reactor design. This multiscale simulation reveals the complex coupling mechanisms in SOEC co-electrolysis, offering theoretical foundations for developing efficient carbon-neutral technologies. Full article

Conventional sources of electricity are limited and they pollute the Earth, so it is necessary to think about an additional source of electricity in the future. Nuclear power is one of the options. Two scenarios using different shares of nuclear power in the future are described in this paper. Scenario 1 describes a moderate increase in nuclear energy use in the future, but with a tendency for a larger increase over 2050. Scenario 2 describes a significant increase in nuclear energy until 2100. Both scenarios are divided into three sub-scenarios (total six) in which the use of different nuclear technologies is analyzed (conventional liquid water reactors, fast breeder reactors and molten salt reactors using thorium as nuclear fuel). In all scenarios, the phase-out of fossil fuel power plants is assumed. One part of the power system is covered by nuclear power plants, and the remaining part is covered by renewable energy power plants. After 2050, an increasing share of the electricity system will be taken over by RES power plants. Nuclear fuel stocks are also analyzed. It is calculated that currently known nuclear fuel stocks are sufficient to meet the needs in all six scenarios. The carbon dioxide emissions saved due to nuclear energy use instead of conventional energy power plants are calculated. The CO_2eq emission savings for Scenario 1 is 87.4% of the recommended emission savings under the IPCC. The CO_2eq emission savings for Scenario 2 is more than sufficient. A calculation of the economic profitability of nuclear energy use is made in relation to fossil power plants and renewable energy power plants. According to calculations, nuclear energy is profitable compared to other energy sources. Nuclear energy use is positive from all the mentioned aspects. Full article

Biomass fluidized bed gasification technology has attracted significant attention due to its high efficiency and clean energy conversion capabilities. However, its industrial application has been limited by insufficient technological maturity. This paper systematically reviews the research progress on biomass fluidized bed gasification characteristics; compares the applicability of bubbling fluidized beds (BFBs), circulating fluidized beds (CFBs), and dual fluidized beds (DFBs); and highlights the comprehensive advantages of CFBs in large-scale production and tar control. The gas–solid flow characteristics within CFB reactors are highly complex, with factors such as fluidization velocity, gas–solid mixing homogeneity, gas residence time, and particle size distribution directly affecting syngas composition. However, experimental studies have predominantly focused on small-scale setups, failing to characterize the impact of flow dynamics on gasification reactions. Therefore, numerical simulation has become essential for in-depth exploration. Additionally, this study analyzes the influence of different gasification agents (air, oxygen-enriched, oxygen–steam, etc.) on syngas quality. The results demonstrate that oxygen–steam gasification eliminates nitrogen dilution, optimizes reaction kinetics, and significantly enhances syngas quality and hydrogen yield, providing favorable conditions for downstream processes such as green methanol synthesis. Based on the current research landscape, this paper employs numerical simulation to investigate oxygen–steam CFB gasification at a pilot scale (500 kg/h biomass throughput). The results reveal that under conditions of O₂/H₂O = 0.25 and 800 °C, the syngas H₂ volume fraction reaches 43.7%, with a carbon conversion rate exceeding 90%. These findings provide theoretical support for the industrial application of oxygen–steam CFB gasification technology. Full article

The continuous change in the entrance cross-section of a parallel-plate flow channel generally affects the mass and heat transfer on the walls of the channel. In this paper, an electrochemical parallel-plate flow channel equipped with a selenoid pulse generator has been developed to enhance the convective mass transfer on the walls of a mass transfer flow system such as an electrodeposition cell, absorption column, flow reactor, etc. A number of experimental studies have been conducted to determine the distribution of the mass transfer coefficients on the bottom wall of a parallel-plate channel for the flow conditions with/without a pulse in the research. Here, the distribution of the convective mass transfer coefficients has been determined by the electrochemical limiting diffusion current technique (ELDCT) using nickel local cathodes arranged on the bottom surface of the flow channel. The experimental results show the effects of the parameters used, which are the flow Reynolds number, opened/closed (OP/CL) ratio, and pulse number, on the distribution of mass transfer coefficients. The results have revealed that the pulse generator altered the flow structure and increased the turbulent intensity at Re < 2860 flow conditions. Within the range of Reynolds number 950 < Re < 2860, the mass transfer correlation was given as $Sh=67.02{Re}^{0.897}{\left({\displaystyle \frac{Op}{Cl}}\right)}^{-0.059}S{c}^{1/3}$. According to the research findings, the highest k_M values were obtained at Re = 2860 with an (OP/CL) ratio of 1/2. If a parallel-plate flow reactor with a pulse generator is designed using these flow conditions, it will yield a reactor that is both more efficient and more compact than a reactor without a pulse generator. Full article

This paper addresses the increasingly severe issue of exceeding short-circuit current limits brought about by the rapid development of large power grids. It investigates the principles of short-circuit current control and methods to limit short-circuit current through the modification of grid equipment. Building on the current state of research, this study introduces different types of impedances to analyze their effects on the control of short-circuit currents, thereby exploring the principles of short-circuit current control based on the composition of actual grid short-circuit currents. Regarding the issue of controlling short-circuit current levels in large power grids, a detailed analysis is conducted of the operational principles, advantages, and disadvantages of five types of modified grid equipment for limiting short-circuit current: high-impedance generators, high-impedance transformers, current-limiting reactors, fault current limiters (FCLs), and a generator–transformer–line group unit. This study identifies the applicable conditions for each short-circuit current-limiting measure and presents specific engineering simulation cases to validate their effectiveness in limiting short-circuit currents, thus determining the control effects of each limiting measure. The results indicate that this research plays an important role in controlling short-circuit currents in power systems, maintaining the safe and stable operation of power systems, and improving the structural framework of power systems. Full article

Thermal energy storage technologies are essential for balancing energy demand and supply. There are three main types: sensible heat, latent heat, and thermochemical energy storage. Among them, thermochemical energy storage offers the highest energy density (1–3 GJ/m³) and long-term storage capability. Salt hydrates have attracted attention as energy storage materials due to their low cost, wide availability, and operating temperatures being well-suited for residential and low-temperature applications. This review focuses on the use of salt hydrates in sorption-based thermochemical energy storage systems. It summarizes the current state of knowledge, including screening studies of various salt hydrates, their thermodynamic and operational limitations, advantages, and performance in composite materials. This review also covers recent projects and common reactor designs used in TCES applications. Based on the literature analysis, the most promising salt hydrates for sorption-based TCES systems include SrCl₂, SrBr₂, K₂CO₃, MgSO₄, MgCl₂, and CaCl₂. Despite the high theoretical energy density of many salt hydrates, future work should focus on experimental studies in large-scale reactor systems to better evaluate the practical discharge behavior of the energy storage system beyond theoretical hydration enthalpies or small-scale thermal analyses. Full article

In this review, we trace the evolution of liquid chromatography from the pioneering work of Tennikova and Svec to the current monolithic polymethacrylate supports for performing liquid chromatography with biological macromolecules and nanoparticles, which offer rapid, high-throughput separations. By using interconnected channels with a tailored channel diameter, monoliths minimize the diffusion limitations typical of particle-based systems. Radial flow designs and optimized channel architectures enable the direct loading of complex biological fluids, reducing the need for sample preparation and optimizing the purification of large biomolecules and nanoparticles such as proteins, nucleic acids, extracellular vesicles, and viruses. Recent work has integrated monoliths into immunoaffinity and enzyme reactor platforms, streamlining analytical workflows and preparative applications in vaccine production and gene therapy. The ongoing advances in monolithic materials, channel geometry, and continuous processing hold promise for even greater efficiency and scalability in future applications. Full article

Knowledge of alloy behavior under industry-relevant conditions is critical to hydrogen production and processing, yet it is currently limited. To understand more about the impact of hydrogen damage on stainless steel 316 under realistic in-service conditions, we conducted a forensic investigation of two reactors exposed to various hydrogen-processing conditions. We examined samples of reactor walls exposed to hydrogen-containing atmospheres for >100 and ~1000 h at elevated temperatures during hydrogen separation and ammonia cracking. The samples were characterized by tensile testing, stretch–bend testing, and three-point bending. A loss in ductility and strength was observed for the reactor wall material compared with both untreated materials and materials annealed in neutral atmospheres at the same temperatures used during reactor operation. The three-point bend testing, which was conducted on inner and outer pipe-surface material extracted via electrical discharge machining, showed larger changes in the flexural modulus of exposed reactors but increases in the elastic limit. Microstructural observations revealed that hydrogen may play a role in stress relaxation, possibly promoting normalization at lower-than-expected temperatures. We also observed that materials exposed to ammonia undertake more damage from nitriding than from hydrogen. Full article