Search Results (234)

This study uses life cycle analysis (LCA) to evaluate the environmental impacts of co-firing bituminous coal with agricultural biomass waste, such as coconut and rice husks, emphasising circular economy principles. Seven experimental scenarios with different coal-to-biomass ratios were designed, ranging from pure coal to pure biomass. The results show that Scenario B (100% rice husk) achieved the best overall environmental performance, with the lowest global warming potential (300 kg CO₂ equivalent), eutrophication potential (4.742 kg PO₄ equivalent), and smog formation potential (0.012 kg C₂H₄ equivalent). Additionally, Scenario F (15% biomass mix) recorded the lowest acidification potential (57.39 kg SO₂ eq), indicating that even partial substitution can yield significant environmental benefits. In contrast, Scenario C (100% coal) exhibited the highest acidification (164.08 kg SO₂ eq) and eutrophication (8.82 kg PO₄ eq) potential. Overall, the results demonstrate that co-firing biomass waste significantly reduces pollutant emissions compared to burning coal alone. This study highlights the effectiveness of biomass waste co-firing in mitigating environmental impacts, promoting resource recovery, and supporting a sustainable energy transition within a circular economy framework. Full article

Co-firing large-sized straw biomass in pulverized coal boilers is a potential pathway for carbon emission reduction in China’s thermal power plants. However, experimental data on large-sized straw combustion under pulverized coal boiler combustion conditions are critically lacking. This study selected typical large-sized wheat straw particles. Employing a two-mode experimental setup in a drop tube furnace (DTF) system simulating pulverized coal boiler conditions, we systematically investigated the combustion behavior and alkali metal release characteristics of this large-sized straw biomass, with combustion processes summarized for diverse particle types. The findings reveal asynchronous combustion progression across particle surfaces due to heterogeneous mass transfer and gas diffusion; unique behaviors distinct from denser woody biomass, including bending deformation, fiber branching, and fragmentation, occur; significant and morphology-specific deformations occur during devolatilization; fragmentation universally produces particles of varied shapes (needle-like, flaky, blocky, semi-tubular) during char combustion; and potassium release exceeds 35% after complete devolatilization and surpasses 50% at a burnout degree exceeding 80%. This work provides essential experimental data on the fundamental combustion characteristics and alkali metal release of large-sized wheat straw particles under pulverized coal boiler combustion conditions, offering engineering application guidance for the direct co-firing of large-sized flexible straw biomass in pulverized coal boilers. Full article

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

Accelerating the low-carbon transition of China’s coal-fired power sector is essential for advancing national sustainability goals and fulfilling global climate commitments. This study introduces an integrated, data-driven analytical framework to facilitate the sustainable transformation of the coal power sector through coordinated unit-level retirements, new capacity planning, and targeted retrofits. By combining a comprehensive unit-level database with a multi-criteria evaluation framework, the analysis incorporates environmental, technical, and economic factors into decision-making for retirement scheduling. Scenario analyses based on the China Energy Transformation Outlook (CETO 2024) delineate both baseline and ideal carbon neutrality pathways. Optimization algorithms are employed to identify cost-effective retrofit strategies or portfolios, minimizing levelized carbon reduction costs. The findings reveal that cumulative emissions can be reduced by 10–14.9 GtCO₂ by 2060, with advanced technologies like CCUS and co-firing contributing over half of retrofit-driven mitigation. The estimated transition cost of 6.2–6.7 trillion CNY underscores the scale of sustainable investment required. Sensitivity analyses further highlight the critical role of reducing green hydrogen costs to enable deep decarbonization. Overall, this study provides a robust and replicable planning tool to support policymakers in formulating strategies that align coal power sector transformation with long-term sustainability and China’s carbon neutrality commitments. Full article

The “carbon neutral power generation” policy of the European Union requires the phasing out of fossil fuel power plants. These plants still play a crucial role in the energy mix in many countries; therefore, efforts are put forward to lower their CO₂ emissions. The available solution for an existing coal plant is the implementation of biomass co-firing, which allows it to reduce twice its carbon footprint in order to achieve the level of natural gas plants, which are preferable on the way to zero-emission power generation. However the side effect is a significant increase in the bulk fuel volumes that are acquired, handled, and finally supplied to the power plant units. A necessary extension of the complex logistic system for unloading, quality tagging, storing, and transporting biomass may increase the plant’s noise emissions beyond the allowed thresholds. For a comprehensive assessment of the concept of expanding the power plant’s biofuel supply system (BSS), a discrete simulation model was built to dimension system elements and verify the overall correctness of the proposed solutions. Then, a dedicated noise emission model was built for the purposes of mandatory environmental impact assessment procedures for the planned expansion of the BSS. The noise model showed the possibility of exceeding the permissible noise levels at night in selected locations. The new simulations of the BSS model were used to analyze various scenarios of biomass supply with regard to alternative switching off the selected branches of the whole BSS. The length of the queue of unloaded freight trains delivering an average quality biomass after a period of 2 weeks is used as a key performance parameter of the BSS. A queue shorter than 1 freight train is accepted. Assuming the rising share of RESS in the Polish energy mix, the thermal plant’s 2-week average power output shall not exceed 70% of its maximum capacity. The results of the simulations indicate that under these constraints, the biofuel supplies can be sufficient regardless of the nighttime stops, if 50% of the supplied biomass volumes are delivered by trucks. If the trucks’ share drops to 25%, the plant’s 2-week average power output is limited to 45% of its maximum power. The use of digital spatial simulation models for a complex, cyclical-continuous transport system to control its operation is an effective method of addressing environmental conflicts at the design stage of the extension of industrial installations in urbanized areas. Full article

In the aerospace, energy and nuclear energy sectors, dynamic pressure measurement of power equipment and pressure vessels in high-temperature environments is critical for validating design, manufacturing processes and operational condition monitoring. The existing electric sensors are resistant to temperature. It is difficult to meet the pressure measurement requirements of high temperature and high-frequency responses. In this paper, combining the material properties of high-temperature co-fired ceramics (HTCC) with the structural characteristics of Fabry–Perot, an all-ceramic fiber-optic Fabry–Perot high-temperature pulsating pressure sensor based on a HTCC pressure- sensing diaphragm and ceramic high-temperature sintering process, is proposed. Experimental results show that in the pressure range of 6 MPa, the static pressure sensitivity of the sensor is 1.30 nm/MPa, and the linear goodness of fit reaches 0.99913. The dynamic response frequency of the sensor reaches 598.5 kHz. The survival time at high temperature of 800 °C is more than 80 h. The sensitivity to temperature is 0.00475 nm/°C. Full article

Ammonia is gaining increasing attention as a zero-carbon fuel and hydrogen carrier, offering high energy density, mature liquefaction infrastructure, and strong compatibility with existing energy systems. This review presents a comprehensive summary of the recent advances in ammonia-based clean energy systems. It covers the fuel’s physicochemical properties, green synthesis pathways, storage and transport technologies, combustion behavior, NO_X formation mechanisms, emission control strategies, and safety considerations. Co-firing approaches with hydrogen, methane, coal, and DME are evaluated to address ammonia’s low reactivity and narrow flammability limits. This paper further reviews engineering applications across power generation, maritime propulsion, and long-duration energy storage, drawing insights from current demonstration projects. Key technical barriers—including ignition delay, NO_X emissions, ammonia slip, and economic feasibility—are critically examined. Finally, future development trends are discussed, highlighting the importance of integrated system design, low-NO_X combustor development, solid-state storage materials, and supportive policy frameworks. Ammonia is expected to serve as a strategic energy vector bridging green hydrogen production with zero-carbon end-use, facilitating the transition to a sustainable, secure, and flexible energy future. Full article

Micromixing is a crucial process in microfluidic systems. In biochemical and chemical analysis, the sample is usually tested with reagents. These solutions must be well mixed for the reaction to be possible, generally using micromixers manufactured with sophisticated and expensive technology. The present work shows the design and evaluation of micromixers fabricated with LTCC (low-temperature co-fired ceramics) and FDM (fused deposition modeling) technologies for the development of functional and complex geometries. Two-dimensional planar serpentine and 3D chaotic convection serpentine micromixers were manufactured and implemented in an automated microanalytical system using photometric methods. To evaluate the performance of the micromixers, flow, mixing and absorbance measurements were carried out. Green tape and PP materials were used and showed good resistance to the acidic chemical solutions. The devices presented achieved mixing times in seconds, a reduced dispersion due to their aspect ratio, high sensitivity, and precision in photometric measurement. The optical sensing cells stored sample volumes in a range of 10 to 600 µL, which allowed the reduction of reagent consumption and waste generation. These are ideal characteristics for in situ measurement, portable, and low-cost applications focused on green chemistry and biochemistry. Full article

Climate change is a global issue that has gained much attention recently. Co-firing biomass with coal/waste coal reduces the electricity sector’s GHG emissions sustainably. This study uses commercial software to model waste coal and biomass co-firing in 100 MW and 600 MW power plants. The objective is to assess the effects of fluid types (subcritical and supercritical), plant capacities (100 MW and 600 MW), boiler types (pulverized coal and circulating fluidized bed boilers), biomass and waste coal co-firing ratios (0:100, 20:80, 40:60, 60:40, 80:20, and 100:0), and carbon capture and storage efficiencies (0%, 90%, 95%, and 97%) on performance parameters such as net plant efficiency, heat rate, net plant CO₂ and SO₂, and particulate matter emissions. The feedstocks selected for this investigation include anthracite waste coal and loblolly pine biomass. As the biomass fraction increases from 0% to 100%, co-fired power plants net efficiency increases by 3–8%. Supercritical plants had a 6% higher net plant efficiency than the subcritical plants. The study found that the biomass’s high heating value decreased the fuel flow rate and reduced plant CO₂ emissions by 10–16%. With 100% biomass power plant feed and 90% carbon capture and storage efficiency, CO₂ emissions drop by 83% and SO₂ and PM emissions drop to zero. Full article

In order to meet the demand for high-frequency current sensors in 5G communication and new energy fields, there is an urgent need to develop high-performance nickel-zinc ferrite-based co-fired ceramic magnetic cores. In this study, a nickel-zinc ferrite core based on low temperature co-fired ceramic (LTCC) technology was developed. The regulation mechanism of BaCo_0.06Bi_0.94O₃ doping on the low-temperature sintering characteristics of NiZn ferrites was systematically investigated. The results show that the introduction of BaCo_0.06Bi_0.94O₃ reduces the sintering temperature to 900 °C and significantly improves the density and grain uniformity of ceramics. When the doping amount is 0.75 wt%, the sample exhibits the lowest coercivity of 35.61 Oe and the following optimal soft magnetic properties: initial permeability of 73.74 (at a frequency of 1 MHz) and quality factor of 19.64 (at a frequency of 1 MHz). The highest saturation magnetization reaches 66.07 emu/g at 1 wt% doping. The results show that BaCo_0.06Bi_0.94O₃ doping can regulate the grain boundary liquid phase distribution and modulate the magnetocrystalline anisotropy, which provides an experimental basis and optimization strategy for the application of LTCC technology in high-frequency current sensors. Full article

Monitoring internal pressure and temperature in lithium-ion batteries is essential for investigating internal chemical reactions, failure mechanisms, and providing early warnings of thermal runaway. The existing sensors face challenges in withstanding the high temperatures and corrosive electrolytes inside lithium-ion batteries. This work develops an integrated sensor with high robustness using low-temperature co-fired ceramic (LTCC) technology, which incorporates a multilayer ceramic circuit board, a digital pulse temperature sensor, a MEMS pressure sensor, and a microcontroller. It offers the real-time monitoring of pressure and temperature with digital output and calibrated accuracy, achieving a pressure resolution of 1 kPa with 0.085% F.S. accuracy and a temperature resolution of 0.1 °C with deviations under 0.5 °C. The pressure and temperature signals are independently output with drift below 0.067 kPa/°C. The integrated sensors were implanted into a pouch and prototype lithium-ion battery, respectively, for charge–discharge cycle monitoring. The results demonstrated that the integrated sensors could detect cyclic variations in pressure and temperature during charging and discharging until battery failure. Furthermore, the integrated sensors showed high stability after being immersed 60 days in the corrosive electrolyte, suggesting their potential as a novel method for monitoring the internal pressure and temperature of lithium-ion batteries. Full article

The residue of the so-called fibrous seed from the açai fruit represents 70% of the mass of the fruit and has potential for useful energy generation. Evaluating and treating the residue as a renewable fuel offers both economic and environmental benefits, whereas today, it is disposed of as organic waste. The co-firing of the fibrous seed and coal in fluidized bed boilers is an attractive option due to the high efficiency of the combustion process and the low bed temperature. However, one of the issues for this application is the low seed ash sintering temperature, which promotes the agglomeration of the bed material. This work aims to present a new procedure for evaluating the sintering temperature of açai seed and coal ash, making it simpler and consistent with traditional techniques. The proposed procedure for determining the starting ash sintering temperature is based on two simple and dynamic methodologies: simultaneous thermal analysis (STA) and sintering by an area reduction in ash samples. The data obtained allow us to determine that the coal ash begins to sinter at around 1000 °C, while the açai seed ash starts at around 700–850 °C, exhibiting a significant area reduction. Full article

The Indonesian government has established an energy transition policy for decarbonization, including the target of utilizing hydrogen for power generation through a co-firing scheme. Several studies indicate that hydrogen co-firing in gas-fired power plants can reduce CO₂ emissions while improving efficiency. This study develops a simulation model for hydrogen co-firing in an M701F gas turbine at the Cilegon power plant using Aspen HYSYS. The impact of different hydrogen volume fractions (5–30%) on thermal efficiency and CO₂ emissions is analyzed under varying operational loads (100%, 75%, and 50%). The simulation results show an increase in thermal efficiency with each 5% increment in the hydrogen fraction, averaging 0.32% at 100% load, 0.34% at 75% load, and 0.37% at 50% load. The hourly CO₂ emission rate decreased by an average of 2.16% across all operational load variations for every 5% increase in the hydrogen fraction. Meanwhile, the average reduction in CO₂ emission intensity at the 100%, 75%, and 50% operational loads was 0.017, 0.019, and 0.023 kg CO₂/kWh, respectively. Full article

Reactive bonding can overcome the issues associated with conventional soldering processes, such as potential damage to heat-sensitive components and the creation of thermomechanical stress due to differing coefficients of thermal expansion. The risk of such damage can be reduced by using localized heat sources like reactive multilayer systems (RMS), which is already a well-established option in the field of silicon or metal bonding. Adapting this process to other materials, such as low temperature co-fired ceramics (LTCC), is difficult due to their differing properties, but it would open new technological possibilities. One aspect that significantly affects the quality of the bonding joints is the pressure applied during the bonding process. To investigate its influence more closely, various LTCC samples were manufactured, and cross-sections were prepared. The microscopical analysis reveals that there is an optimum range for the bonding pressure. While too little pressure results in the formation of lots of voids and gaps, most likely in poor mechanical and electrical properties, too high pressure seems to cause a detachment of the metallization from the base material. Full article

Combined Cycle Combined Heat and Power (CCCHP) systems enhance energy efficiency and reduce emissions by simultaneously generating electricity and heat. This study presents the energy and exergy performance, environmental impact, and efficiency optimization of CCCHP combustion systems using Ebsilon Professional 16 software simulation. Three fuel combustion CCCHP systems of coal, biomass, and coal–biomass cofiring were simulated for 150 MW of total power output with 125 MW of electrical power and 25 MW of a heating energy system. The sensitivity analysis was performed for 16 different systems with the fuel moisture content varying from 10% to 40% (w/w) to identify the energy and environmental effect on simulated CCCHP systems. The simulation results indicate that increasing biomass moisture content enhanced flue gas energy and improved the Rankine cycle performance. The energy efficiency of biomass and coal–biomass combustion CCCHP systems increased from 56.90% to 67.22% and 56.94% to 62.37, with the moisture content rising from 10% to 30% (w/w) and 10% (w/w) to 25.56% (w/w), respectively, but declined beyond these. Moreover, the exergy efficiency showed a similar pattern peaking at 50.06% in biomass samples and 50.10% in the cofiring sample. Furthermore, the environmental impact, CO₂ and SO₂ emission concentrations reduced from 22.42% (w/w) to 20.77 (w/w) and 0.66% to 0.61%, respectively, with an increase in fuel moisture content from 10% to 25.56% in a biomass cofired combustion CCCHP system. Full article