Unit Energy Research Articles

Investigating the Effects of Different Types of Battery Impacts in Energy Storage Systems on Standalone Hybrid Renewable Energy Systems

Energy plays an important role in the development of a country. Developing countries tend to lean towards the use of domestic renewable energy sources to reduce their dependency on foreign energy. However, when looking at the world as a whole, the share of fossil fuels in energy production is at high levels. Due to the rapid depletion of fossil fuels and their increasing costs, as well as the environmental damage they cause, electricity generation from cheaper and cleaner renewable energy sources is being targeted in the area where work will be done. Hybrid energy systems are used in conjunction with backup Unitss due to the variable nature of renewable energy sources such as wind and solar. In this study, a hybrid energy system with solar-wind-diesel generator-battery components was designed through HOMERPro software to meet the electricity demand of the closed prison in Burhaniye district of Balikesir. Simulations were carried out by applying 5 different battery scenarios in the hybrid energy system, and the optimum result was obtained. As a result, the effect of the batteries used on the system was examined, and the vanadium redox battery system with a high renewable energy ratio and the lowest Units energy cost was determined to be the most optimum.

Technical and Economic Performance of Four Solar Cooling and Power Co-Generated Systems Integrated With Facades in Chinese Climate Zones

Abstract There has been an increasing interest in solar-driven combined energy supply systems for low-temperate applications, particularly those based on the Organic Rankine Cycle (ORC), Kalina Cycle (KC), or Trilateral Cycle (TLC). However, systems based on these thermodynamic cycles usually employ large area collectors that stand alone or are placed on the roof, without considering integration with the building facade. This research presents a solution to large-scale photothermal utilization integrated with facades for co-generated systems. The current study is the first to conduct performance and economic assessment for four novel solar cooling and power (SCP) co-generated systems driven by evacuated tube solar collectors (ETCs) or semi-transparent photovoltaic (STPV) integrated into the building facades. The suggested systems were simulated using TRNSYS to forecast their performance metrics when used in four Chinese cities with various climate zones. As indicators, a solar fraction (SF) and unit energy cost (UEC) were used to evaluate the technical and financial aspects of each system. The STPV-vapor compression cycle (VCC) system had the highest SF (100%, except Haikou), as well as the lowest UEC (0.211$/kWh on average) among the four cities, according to the results. Among the three solar–thermal co-generation systems, ETC–ORC–VCC had the best performance (SF,37.9%; UEC,0.597$/kWh on average).

Internal Flow Phenomena of Two-Way Contra-Rotating Axial-Flow Pump-Turbine with Various Numbers of Blades in Pump Mode

The focus of this paper is to investigate how various numbers of blades impact the performance of a two-way contra-rotating axial-flow pump-turbine when operating in pump mode. In order to meet the two-way operation of the pump-turbine, the front and rear impellers are mirror-symmetric with the same hydraulic model, which ensures the consistent performance of the forward and reverse working conditions. However, when the two-stage impellers have the same number of blades, the dynamic–dynamic interference can be severe, which can threaten the stability of the unit. The present study explores the use of two-stage impellers with varying numbers of blades as a means of enhancing the performance of tidal energy units. By conducting numerical simulations on the front and rear impellers under different flow rates in pump mode, the impact of increasing the number of blades in each stage on the external characteristics of the pump-turbine is revealed. The internal flow characteristics of different models are analyzed, and the impact of the number of blades on the vortex is studied. Different blade numbers will have a certain impact on the internal flow of the two-way contra-rotating axial-flow pump–turbine. Increasing the number of blades will affect the development of tip-leakage vortices and promote their intersection with the wake. In addition, changes in the number of blades will have an impact on the location of the leading edge (LE) water impact on the rear impeller, which in turn affects the contours of vorticity of the rear impeller near the LE and the location of the suction surface (SS) flow separation. The findings of this study offer valuable insights for future research on the operation of contra-rotating axial-flow pump-turbines.

Evolution trend analysis of carbon emissions in light industrial parks: A system dynamics approach

AbstractThe industrial sector is China's major element of energy consumption and carbon emissions, and carbon emissions reduction in industrial parks has become an important foothold in carbon reduction work. Predicting the future evolution trend of carbon emissions in industrial parks under different policy orientations is of great significance for China to achieve the carbon emissions peaking and carbon neutrality goals. Based on the current status of electricity consumption and carbon emissions in industrial parks, this paper takes a light industrial park as the research object, analyzes the source of carbon emissions in this park, combines the characteristics of resource endowment and industrial structure, and considers the factors influencing society, load curve, energy supply and carbon sink, thus constructing a system dynamics model of carbon emission evolution for this park. Different influencing factors are selected to set multiple target scenarios, and the GDP, carbon emissions, carbon emissions reduction and near‐zero carbon evaluation coefficient of light industrial parks are used as characterization indicators for simulation analysis. The analysis results revealed that the comprehensive scenario set by increasing the maximum installed capacity of renewable energy units and raising the proportions of environmental and science and technology inputs while adjusting the industrial growth rate of the park performed best. In this scenario, the economic development of the park and the process of carbon emissions reduction are considered.

Connecting multiple vehicular PEM fuel cells to electrical power grid as alternative energy sources: A Case Study

Advances in fuel cell (FC) technology make them an alternative energy source in several applications such as static, portable, and transportation. Recently, the energy needs of hydrogen electric vehicles, which have developed as an alternative to battery electric vehicles (BEVs) and have significant potential in the future, are met by vehicular hydrogen FCs. In this regard, fuel cell electric vehicles (FCEVs), which have started to take their place in the transportation sector, can also be used as an additional energy source with their energy unit for electrical power grid-connected systems. In grid-vehicle integration, vehicular FCs can meet a significant part of the electricity consumption when parked and help stabilize the grid. In this study, multiple vehicular PEM fuel cells (PEMFCs), the most widely used in FCEVs, support the residential grid by injecting electrical power into the connecting system. For this, a multi-input dc-dc boost converter interface is designed and utilized to manage electrical energy from vehicular PEMFCs to the electrical power grid instead of a conventional single-input dc-dc boost converter. In the dc-dc converter control, Incremental-Conductance (InC) maximum power point tracking (MPPT) method is utilized to extract maximum power from PEMFCs. Subsequently, the extracted electrical energy is supplied to the grid through a full-bridge inverter controlled by hysteresis pulse width modulation. The designed grid-support system supplied by vehicular PEMFCs in the ratings of 75 kW, 100 kW, and 125 kW are connected to local dynamic loads and analyzed for a 24-h operation. The minimum load consumption value is 84.6 kWh at midnight while load consumes at most 396.2 kWh during the daytime. Various connection situations of vehicular PEMFCs are considered to examine the energy flow analysis between vehicles and the grid/consumer side. A detailed economic analysis has been carried out by using hourly energy values in terms of load profile and generated energy to show the profit amount on the user side. While the cost of the energy consumed by the loads is calculated as €1004.8 without connection to the grid of FCEVs, the amount of profit obtained on the load side is measured as €943.9 with the connection.

Multi-flow optimization of a greenhouse system: A hierarchical control approach

Greenhouses are implemented all over the world to increase agricultural production thanks to controlled environmental conditions (inside temperature, moisture and CO2 contents). However, such systems are energy-intensive. The presented work focuses on controlling a greenhouse’ onsite multi-energy system (gas, heat and electricity), extended to a multi-flow system as the CO2 produced by the energy units is used as a plant fertilizers. In this view, a three levels hierarchical control has been developed: a steady state economic MPC is combined with a dynamic Multi-energy MPC and low-level PID controllers. This new controller aims at determining the best synergies for economic flows management, subject to compliance with the required climatic conditions in the greenhouse. The proposed controller is applied to a greenhouse which energy system is based on a thermal energy storage fueled by a gas boiler and a combined heat and power unit. The results are confronted to a usual ruled-based controller performed by greenhouses owners, showing a more efficient dynamic functioning of the energy system. Consequently, less gas is consumed (80.79 t to 76.03 t), heat is produced when needed, and electricity from the CHP is economically optimized allowing less importation from the grid (from 17.80 MWh to 15.88 MWh), and profitable selling.

Collaborative optimization of regeneration unit and power generation unit in reverse electrodialysis heat engine for low-grade heat recovery

Reverse electrodialysis heat engine (REDHE) emerges great potential to harvest the low-grade heat (LGH) produced during the industrial processes and renewable energy utilizations. In the closed-loop system, the power generation unit converts the salinity gradient power (SGP) to electric energy using the reverse electrodialysis (RED) cells, and the regeneration unit recovers the salinity gradient based on LGH. As two units are in series, the regeneration and power generation units should be collaboratively optimized to achieve a high performance of REDHE. Herein, a framework which can unitedly simulate the both units is built, which enables to divide the total efficiency of REDHE to the respective efficiencies of units. LiBr solution as the working fluid and the effects of initial salt concentration, concentration of the high concentration (HC) solution and temperature in RED cells are considered. Results show that the total efficiencies increase with the concentration of HC solution and the RED temperature due to the production of more chemical energy in the regeneration unit. However, a non-monotonic trend of the total efficiency with the initial concentration is discovered, which increases from 4.91% to 5.42% and then decreases to 4.69% when the initial concentration raises from 20 wt% to 25 wt% and then reaches 30 wt% at RED temperature of 25 ℃. Although enhancing the RED temperature to 50 ℃ leads the total efficiencies increase to 6.25%, 7.13% and 6.38%, respectively, the trend is unchanged. The respective efficiencies of units explain the phenomenon by that a higher salinity can decrease the efficiency of the power generation unit by reducing the ionic selectivity in the RED cells, but enhance the efficiency of the regeneration unit. Therefore, the highest total efficiency reached at initial concentration of 25 wt% is the trade-off between the efficiencies of two units. This study indicates that increasing the concentration of HC solution, the RED temperature, and carefully selecting a compromise initial concentration are helpful to achieve a high energy efficiency in a REDHE.

Techno-Economical Effects of Adopting Small Capacity Transformers on Ado-Ekiti 11/0.415 kV Power Distribution Networks

The major portion power loss in power system occurs in the components of low voltage (LV) networks. Low voltage distribution system (LVDS) configuration has been observed to contribute significantly to power loss and unacceptable voltage drop in the system due to its structure and higher current flow in the network. The adoption of small capacity transformers as high voltage distribution system (HVDS) configuration is increasingly applied to the network for power loss reduction and the improvement of voltage profile. This study aims to evaluate the technical and economic implication of the use of HVDS configuration on Ado-Ekiti 11/0.415 kV power distribution networks and provide necessary recommendations. The network data was obtained and modeled on NEPLAN software for simulation and technical evaluation of the networks. The existing LV lines were upgraded to high voltage (HV) and remodeled with small capacity transformers and comparative analysis of the technical and economic effects of the networks were carried out. The results obtained showed that there could be feeder capacity increase of 92.03 kW and power loss reduction of 347.17 kW and 459.72 kVar following reconfiguration from LVDS to HVDS. The losses in the transformers and lines were significantly reduced by 37.8% for HVDS configuration when compared with the LVDS configuration. The voltage profile was significantly improved with voltage deviations in the range of ± 0.01 to ± 0.03 of bus voltage for the HVDS network when compared to the existing network. The cost of implementation of the HVDS network substation was calculated to be ₦807,238,715.50 and with the combination of annual savings and an increment in tariff of ₦5/kWh in the billing charge of unit energy consumption resulted in a payback period of 2 to 3 years for the estimated capital investment. This study showed that technical performance of HVDS implementation on the Ado-Ekiti network feeder was better than that of the existing network.

Green hydrogen production and liquefaction using offshore wind power, liquid air, and LNG cold energy

Coastal regions have abundant off-shore wind energy resources, and surrounding areas have large-scale liquefied natural gas (LNG) receiving stations. From the engineering perspectives, there are limitations in unstable off-shore wind energy and fluctuating LNG loads. This article offers a new energy scheme to combine these 2 energy units, which uses surplus wind energy to produce hydrogen, and use LNG cold energy to liquefy and store hydrogen. In addition, in order to improve the efficiency of utilizing LNG cold energy, and reduce electricity consumption for liquid hydrogen (LH2) production at coastal regions, this article introduces the liquid air energy storage (LAES) technology as the intermediate stage, which can stably store the cold energy from LNG gasification. A new scheme for LNG-LAES-LH2 hybrid LH2 production is built. The case study is based on a real LNG receiving station at Hainan province, China, and this article presents the design of hydrogen production/liquefaction process, and carries out the optimizations at key nodes, and proves the feasibility using specific energy consumption and exergy analysis. In a 100 MW system, the liquid air storage round-trip efficiency is 71.0% and the specific energy consumption is 0.189 kWh/kg, and the liquid hydrogen specific energy consumption is 7.87 kWh/kg and the exergy efficiency is 46.44%. Meanwhile, the corresponding techno-economic model is built, and for a LNG-LAES-LH2 system with LH2 daily production 140.4 tons, the shortest dynamic payback period is 9.56 years. Overall, this novel hybrid energy scheme can produce green hydrogen using a more efficient and economical method, and also can make full use of surplus off-shore wind energy and coastal LNG cold energy.

An inertial neurodynamic algorithm for collaborative time-varying energy management for energy internet containing distributed energy resources

This paper investigates the energy management of an Energy Internet (EI) that integrates multiple energy networks. Based on the structure of EI and the fluctuation of load, an optimal energy management model considering part of the load as time-varying factor is proposed. Under the influence of load, the actual energy management problem (EMP) is formulated as a time-varying optimization problem subject to a set of global and local constraints. Its optimal solution varies continuously with time, which leads to difficulties in obtaining optimal solutions by conventional algorithms. Consequently, to obtain better tracking performance, this paper proposes a distributed inertial projection neurodynamics algorithm (DIPNA) based on the Nesterov accelerated gradient descent method. This algorithm tracks the optimal solution of the EMP with a fast convergence rate O1/t2, providing a referenceable active power for each energy unit in real time. Finally, the performance evaluation results demonstrated the effectiveness and fast convergence of the proposed algorithm.

Wave-heat-electricity conversion: Design and analysis of an electromagnetic energy conversion device

An innovative electromagnetic energy harvester was developed using a compact four-ring single-resistor unit cell. To achieve efficient conversion of electromagnetic waves into electricity, we integrated the high-performance Bi2Te3 thermoelectric material onto the load resistor. Remarkably, this unit cell exhibits exceptional energy harvesting capabilities at a frequency of 5.8 GHz while maintaining polarization insensitivity. Through comprehensive analysis, we evaluated the energy harvesting efficiencies, power loss distribution, and current density distribution. Additionally, we investigated the impact of incident power on the unit cell's temperature and energy conversion efficiencies. To enhance energy concentration on the load, we ingeniously designed an “L-shaped” metal through-hole structure within the four-ring single-resistor unit cell. Our results demonstrate that the four-ring single-resistor unit cell achieves an impressive harvesting efficiency of 94.5% at 5.8 GHz, with a thermal conversion efficiency of 43.3 °C/W, an electrical conversion efficiency of 0.23 mV/°C, and an electrical response rate of 9.4 mV/W. Notably, when subjected to a power input of 7 W, the unit cell produces an output voltage of 65.9 mV, and its theoretical maximum output power reaches 180 mW.

Enhanced compression heat recovery of coupling thermochemical conversion to trigenerative compressed air energy storage system: Systematic sensitivity analysis and multi-objective optimization

Compressed air energy storage system has been considered as a promising alternative solution for stabilizing the electricity production driven by intermittent renewable energy sources. However, the inefficient utilization of thermal energy within the compressed air energy storage system hinders the efficient operation of system. Therefore, a novel trigenerative system integrated compressed air and chemical energy storage system is introduced in this study. The proposed system transforms the compression heat to the syngas in the form of chemical energy to achieve energy level upgradation during the charging process, and recuperates the thermal energy at the exit of the gas turbine to increase the inlet temperature of the compressed air for electricity enhancement during the discharging process. The residual heat during the operation process is then conducted for producing cooling and heating outputs simultaneously based on the law of energy cascade utilization. A systematic parametric analysis is carried out to investigate the effects of critical parameters on system comprehensive performance. Furthermore, the multi-objective optimization is employed to find the optimal trade-off among the thermodynamic performance, economic attractiveness and environmental friendliness of the proposed system. The parametric analysis indicates that the operating parameters of air compressor and gas turbine affect the performance indicators of thermodynamic and economic significantly. Moreover, at the best trade-off solution selected by the TOPSIS method, the system reaches 42.96 % of exergetic round trip efficiency, 105.28 $/MWh of levelized cost of energy and 206.94 kg/MWh of CO2 emission per unit energy output.

Study on the optimal circulation structure of liquid desiccant dehumidification system based on composite model

Liquid desiccant dehumidification systems have demonstrated good energy savings and dehumidification effects in extremely hot and humid areas. However, to improve system performance, the matching problem between the desiccant-regeneration solution recirculation ratio and system performance has not been thoroughly investigated. Therefore, in this study, we constructed a liquid desiccant dehumidification system with solution recirculation and set four circulation modes: NS mode without solution recirculation, CS mode with only desiccant solution recirculation, RS mode with only regeneration solution recirculation, and CRS mode with both desiccant and regeneration solution recirculation. The orthogonal test method was used to determine the influence of solution recirculation on the evaluation indicators, and multi-objective optimization of the major parameters under the four circulation modes was performed based on the NSGA-II and TOPSIS algorithms. The results showed a clear conflict between the moisture removal rate (MRR) and energy consumption (Q). In extremely hot and humid areas, a high air flow rate is suitable for use in the regenerator to process small-flow-rate solutions or set larger sizes. Under typical environmental conditions, it is recommended to set up a liquid desiccant dehumidification system with a solution recirculation structure: when MRR demand is high, the CS mode should be used, where MRR is 6.72 g/s; when Q demand is high, the RS mode should be used where Q is 35.34 kW; considering both MRR and Q effects, the CRS mode should be used where unit energy consumption moisture removal rate is 0.1196 g/(s·kW).

Intelligent analysis of landscape architecture based on digital technology under 5G network

In the wake of the wide promotion of 5G network, the era of super-high-speed networks and the Internet of Everything is approaching. Combining digital technologies led by 5G with landscape architecture has become an important way for the sustainable development of garden ecology. In order to achieve refined management of gardens and improve the accuracy and consistency of garden environmental data monitoring, this study constructs a new IoT sensor multi data fusion algorithm model. Considering the high redundancy and large error data collected by multiple sensors, this paper proposes a multi data fusion algorithm based on adaptive trust estimation and improved D-S evidence theory. The experimental data demonstrates that matched with IGA-BP, algorithm in this paper obtained the largest fitness value and the fastest convergence speed in three sensor application scenarios with different numbers of nodes. The lowest values were obtained in terms of unit energy consumption and network latency indicators. In the monitoring experiment for environmental data of landscape architecture, the algorithm obtained lower relative error and mean square error than IGA-BP in four environmental parameters of temperature, humidity, light intensity and carbon dioxide concentration. Therefore, the algorithm is effective in real-time monitoring of landscape garden environmental data, and can provide decision-making data for garden management as a reference.

Maximum salt adsorption tracking in capacitive deionization cell powered by photovoltaic solar panel

Photovoltaic (PV) systems are considered as a support unit and eco-friendly energy source for the desalination system. If the surface of the desalination plant is covered by PV cells, it is possible to produce self energized desalination plants. Capacitive deionization (CDI) is a water purification technology known for its reduced energetic footprint. The cells are supplied with Direct current (DC) power which makes the application of the PV panels logically intuitive. Conventional existing PV maximum power point trackers (MPPT) are similar to each other in hardware as electrically DC modulated and operated, but different in software. Through different algorithms, existing PV power trackers aims battery charging or grid-tie exportation as application. In this study, a new power tracking using the water flow control is presented as an adapted solution for water desalination using the solar power. The developed algorithm is based on Maximum Salt Adsorption Tracking (MSAT). The proposed algorithm shows a comparative performance as other tracking algorithms under varying radiations. Besides, MSAT brings considerable lower costs by eliminating the need of any storage unit and any DC to DC converters. The developed controller is described in detail and comparative simulated/experimental analysis and performance evaluation are presented.

Potential for Thermo-Chemical Conversion of Solid Waste in Canada to Fuel, Heat, and Electricity

The amount of municipal solid waste (MSW) generation in Canada was 34 million tonnes in 2018. Responsible waste management is challenging, but essential to protect the environment and to prevent the contamination of the ecosystem on which we rely. Landfilling is the least desirable option, and diversion through thermo-chemical conversion to value-added products is a good option for difficult-to-recycle waste. In this study, the amounts, moisture contents, heating values, and compositions of municipally collected solid waste produced in Canada are reported, a classification that is suitable for conversion purposes is proposed, and the potential for thermo-chemical conversion is determined. Much of the waste generated in Canada is suitable for being converted, and its potential for heat or electricity generation was determined to be 193 PJ/yr and 37 TWh/y, respectively. The GHG emissions that are saved through diversion from the landfill, while assuming the generated heat or electricity offsets natural gas combustion, gives a GHG reduction of 10.6 MMTCO2E/yr or 1.6% of Canada’s GHG emissions. The blending of waste in feedstocks can have varying effects on the amount of biogenic CO2 produced per unit energy in the feedstock, which is an important consideration for new projects. Other considerations include the heating values, moisture contents, and contaminant levels in the waste.

Calibrating SPI-ACS/INTEGRAL for gamma-ray bursts and re-estimating energetics of GRB/GW 190425 in gamma-ray range

ABSTRACT SPI-ACS/INTEGRAL is one of the most sensitive orbital gamma-ray detectors in energy range above 80 keV. Since 2002 it registered several thousands of gamma-ray bursts (GRBs), including the bursts associated with LIGO-Virgo gravitational wave events GW 170817 and GW 190425. No dedicated in-flight calibrations were performed for SPI-ACS/INTEGRAL, complicating estimation of spectral and energetic characteristics of an event. Using data of GBM/Fermi we perform cross-calibration of SPI-ACS/INTEGRAL, based on 1032 bright GRBs registered by both experiments. We find the conversion factor between instrumental counts from SPI-ACS and energy units from GBM to be dependent on hardness of GRB spectrum (defined as the characteristic energy value, Ep) and on location of a source in spacecraft-based coordinate system. We determine the corresponding analytical model to calculate the conversion factor and estimate its accuracy empirically. Sensitivity of SPI-ACS/INTEGRAL to detect gamma-ray transients is also investigated. Using the calibration we re-estimate energetics of GRB/GW 190425, detected by SPI-ACS/INTEGRAL alone. We constrain possible range of the characteristic energy Ep and isotropic equivalent of total energy, emitted in gamma-rays Eiso for GRB 190425, using the Ep, i–Eiso (Amati) correlation. The calibration model could be applied to any transients with energy spectrum, analogous to GRBs.

Reliable operation of an optimal self-scheduling multicarrier system with two alternatives: Multiple renewable utilities or hydrogen facilities

Multicarrier systems (MCSs) have been retrofitted with storage facilities to enhance their resilience to meet the fluctuating demands. Considering the complexity of the systems and the interactions among various carriers, optimal resource allocation is a serious challenge in the sustainable management of energy systems. This study proposes a new self-scheduling MCS to supply power, heating, cooling, and freshwater, without external cooling and nonrenewable heating facilities. Modeled based on circular integration principle, the MCS consists of various subsystems and storage facilities to treat the effluent and digest excess sludge of a wastewater treatment facility. The MCS is optimally designed and scheduled in a two-stage multi-objective optimization to satisfy the demand loads of a small community in two configurations: one with a material conversion unit (MCS-MC) to store and utilize hydrogen, and the other with weather-driven renewable energy units (MCS-RE) for a reliable operation. Accordingly, total annual cost (TAC), total exergy dissipation (nTED), and the mismatch between supply and demand (MSD) are minimized in a multi-objective optimization problem to obtain the optimal capacity of the equipment and the short-term storage facilities are scheduled in the first and second stages, respectively. The results show that the optimal MCS-MC and MCS-RE configurations reduced the TAC, nTED, and MSD by 30.2% and 12.4%, 32.9% and 23.4%, and 55.4% and 48.5%, respectively, compared to the base system. The new utility-free hydrogen-assisted multi-carrier systems are anticipated to substitute present systems with multiple renewable resources.

The influence of inherent minerals on the constant-current electrolysis process of coal-water slurry

This study investigates the effect of inherent minerals on the constant current electrolysis of coal-water slurry (CWS), which is a potential method for energy-saving and value-added utilization of coal. The products and energy consumption of raw coal and demineralized coal (DM-coal) are compared, and the alkali-soluble and alkali-insoluble components are separated for electrolysis. The results show that minerals increase the yield of water-insoluble acid (WIA) from 30.02% to 60.02% and decrease the unit energy consumption from 2.7 kJ/g to 2.3 kJ/g. Additionally, the inherent minerals also affect the carbon skeleton structure of the products. Compared to DM-coal, the residual coal R4320 from raw coal exhibits lower carbonyl carbons (faC) and smaller sizes of aromatic clusters (Xb). The mechanism underlying the influence of inherent minerals is explored based on the dissolution patterns of minerals and the interaction between oxidizing medium and coal molecules. This study provides insights for energy consumption control and the coupling of anodic CWS oxidation with cathodic carbon dioxide reduction through current modulation.

Effect of Combined Infrared Hot Air Drying on Yam Slices: Drying Kinetics, Energy Consumption, Microstructure, and Nutrient Composition.

Using hot air drying (HAD) and combined infrared hot air drying (IR-HAD) test devices, the drying kinetics, unit energy consumption, color difference values, rehydration rate, microstructure, and changes in polysaccharide and allantoin contents of yam slices were examined at various temperatures (50 °C, 55 °C, 60 °C, 65 °C, and 70 °C). The findings demonstrated that each of the aforementioned parameters was significantly impacted by the drying temperature. IR-HAD dries quicker and takes less time to dry than HAD. The Deff of IR-HAD is higher than that of HAD at the same temperature and increases with the increase in temperature. The activation energy required for IR-HAD (26.35 kJ/mol) is lower than that required for HAD (32.53 kJ/mol). HAD uses more energy per unit than IR-HAD by a factor of greater than 1.3. Yam slices treated with IR-HAD had higher microscopic porosity, better rehydration, lower color difference values, and higher polysaccharide and allantoin levels than HAD-treated yam slices. The IR-HAD at 60 °C had the greatest comprehensive rating after a thorough analysis of the dried yam slices using the coefficient of variation method. Three statistical indicators were used to evaluate six thin-layer drying models, and the Weibull model was most applicable to describe the variation of drying characteristics of yam slices.