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Open-pit mining remains the dominant method for copper extraction in current operations, with blasting playing a pivotal role in the efficiency of downstream processes such as loading, hauling, crushing, and milling. This study assesses the impact of surface blast design parameters on the performance of a comminution circuit processing a copper-bearing ore. The analysis focuses on important design parameters such as burden, spacing, stemming, and powder factor, evaluating their influence on the fragment size distribution and downstream comminution circuit performance. Using the Kuz-Ram model, four novel blast designs are compared against a baseline to predict the size distribution of rock fragments (X80). Key performance indicators throughput and specific energy consumption are calculated to evaluate the comminution circuit performance. Results demonstrated that reducing the X80 from 500 mm to 120 mm led up to a 20% increase in throughput and a 29% reduction in total specific energy consumption. Furthermore, achieving finer particle sizes through more intensive blasting contributed to a reduction in total operating costs by up to 12%. These findings provide valuable insights for optimizing blast design to improve comminution circuit performance, contributing to sustainable mining practices by reducing energy consumption, operating costs, and the environmental footprint of mining operations. [ABSTRACT FROM AUTHOR]

Walnut green husk (WGH) is a common agricultural by-product with high yield and serious pollution problem. The present study aimed to evaluate the impacts of sun drying (SD), pulsed vacuum drying (PVD), short and medium infrared radiation drying (SMIR), hot air drying based on temperature and humidity control (TH-HAD), and heat pump drying (HPD) on the drying characteristics, energy consumption, physico-chemical properties, bioactive compounds content and antioxidant capacity of WGH. Drying characteristics and drying kinetics showed that artificial drying could significantly improve drying efficiency. Compared with SD, the drying time of PVD, SMIR, TH-HAD, and HPD reduced by 63.6, 78.7, 66.3, and 54.0%, respectively. Specific energy consumption analysis demonstrated that HPD showed the lowest specific energy consumption of 2.2 kW·h/kg. Hydration properties analysis revealed that PVD resulted in sample of best water-holding capacity and the HPD sample had the highest water solubility index (43.44%). Structural analysis showed that the cell wall structure of WGH was damaged by different drying methods. Generally, among the five drying methods, HPD was found to be in the middle range in terms of active substance content and antioxidant capacity of dried samples, but it had the least energy consumption. Therefore, HPD has great potential for commercial-scale drying of WGH, offering a new approach for low-energy food processing. [ABSTRACT FROM AUTHOR]

Water shows a strong tendency to absorb the energy of wavelengths of 3 and 6 µm, which are in the infrared (IR) range. Therefore, IR dryers are used to dry food and fruits that have a high‐water content. Thus, modeling and optimizing energy and exergy parameters of terebinth drying in an IR–rotary drum (RD) dryer were evaluated using the response surface methodology. Independent factors included IR power and rotary rotation speed, and response factors were specific energy consumption (SEC), energy efficiency (EFF), exergy efficiency (EXEFF), specific exergy loss (EXLOSS), and exergy improvement potential (EIP). According to the obtained results, the range of EFF and EXEFF was between 28.93%–9.11% and 0.88%–6.62%, respectively. As IR power and RD speed increased, SEC (123.75–39.21 MJ/kg), EXLOSS (3.97–2.97 MJ/kg), and EIP (3.62–1.009 MJ/kg) decreased, while EFF and EXEFF increased. The results obtained in this study showed that the optimal IR drying power is 616.39 W, and the optimal rotary rotation speed is 13.46 rpm. [ABSTRACT FROM AUTHOR]

This study aims to develop a novel microwave integrated‐swirling flow‐fluidized bed drying system. In this regard, for better understanding the drying performance and energy consumption of this novel system and its effect on the product quality parameters, the experiments were performed by using green tea leaves. Also, mathematical modeling and energy analysis was performed for this novel system. Drying experiments were carried out for 100, 300, 600, and 800 W microwave powers and some critical drying parameters such as dimensionless moisture ratio, moisture content, and drying rate were computed. Moreover, specific energy consumption (SEC), specific moisture extraction rate, and thermal efficiency of the system were estimated. Accordingly, the best drying curve equation was obtained as Improved Midilli‐Kucuk model for all microwave powers. Moreover, the highest water extract, the maximum caffeine, and the minimum total ash of the product were determined to be 43.83%, 2.2%, and 5.94%, respectively, at 800 W power. Minimum SEC, maximum specific moisture extraction rate, and maximum energy efficiency of the system were estimated as 11.4 KWh kg−1, 0.088 kg KWh−1, and 23.7% at 800 W, respectively. [ABSTRACT FROM AUTHOR]

Forward Osmosis (FO), a membrane desalination technology and Capacitive Deionization (CDI), an electrically operated desalination technology, are numerically integrated utilizing four different configurations for the high-water recovery rate and ultrapure water production from brackish water resource. To minimize the wastewater rejection, the CDI desorption stream is continuously fed to the FO unit, efficiently recovering the remaining freshwater. To produce ultrapure water, freshwater stream obtained from FO is provided to the CDI cell, which adsorbs the remaining dissolved solute particles. These two configurations serve the purpose of both industrial as well as domestic water supply requirements. Continuing this concept, the formation of the other two configurations allows us to obtain fresh water and ultrapure water simultaneously and up to a 90% freshwater recovery rate for the areas with inadequate supply. The performance parameters to assess the integration are the Water Recovery Rate (WRR) and Specific Energy Consumption (SEC). The first configuration (CDI-FO), proposed for a high freshwater recovery rate, resulted in 79.33% WRR with an SEC of 0.689 ${\bi \; }{\rm kWh}/{\rm m}^3$ kWh / m 3 . While, for the second configuration (FO-CDI), 34.25% water was recovered as 2.87 ppm ultrapure water along with 34.25% freshwater. The third proposed configuration (CDI-FO-CDI) had a WRR of 79.33%, 14.67% of which was recovered as ultrapure water of concentration 2.86 ppm. The fourth configuration (CDI-FO-FO) developed for high water recovery, removed the maximum of water from the feed stream with a WRR of 91.33% and remained energy-efficient, consuming an SEC of 0.908 $\; {\rm kWh}/{\rm m}^3$ kWh / m 3 . [ABSTRACT FROM AUTHOR]

This study aims to evaluate the electrochemical oxidation of real textile wastewater using boron-doped diamond (BDD) and different titanium-based mixed metal oxide (Ti/MMO) commercial anodes, namely Ti/RuO2-TiO2, Ti/IrO2-Ta2O5, Ti/IrO2-RuO2, and Ti/RuO2/IrO2-Pt. Experiments were conducted in batch mode, with stirring, at different applied current densities. The results showed that BDD attained the best results, followed by Ti/RuO2-TiO2, which achieved total color removal, a chemical oxygen removal of 61% with some mineralization of organic compounds, and a similar specific energy consumption to BDD. The worst performance was observed for Ti/IrO2-Ta2O5, with a specific energy consumption four times superior to BDD due to a negligible organic load removal. [ABSTRACT FROM AUTHOR]

A microwave-hot air belt dryer (MHABD) showed high specific energy consumption (SEC) due to its limited material processing capacity and extended drying time. Thus, this research presents the development and performance evaluation of an industrial microwave-hot air belt dryer (IMHABD) for drying Namdokmai Sithong mango slices. The IMHABD system, optimized using the COMSOL Multiphysics program, features a 0.9 m × 4.08 m × 0.5 m chamber with 36 magnetrons having a maximum microwave power of 28,800 W (each magnetron produces 800 W) at a frequency of 2,450 MHz. Two drying methods were studied, step-down microwave power drying (IMHABD-S) and constant microwave power drying (IMHABD-C). IMHABD-S, with a power range of 150–350 W combined with hot air at 65 °C, outperformed IMHABD-C, delivering enhanced drying rates, improved color attributes, and reduced shrinkage, along with decreased hardness and toughness values. All dried slices had a water activity lower than 0.6. An IMHABD-S operated at 350 W for 1.5 h showed the lowest SEC. Economic analysis revealed strong support for the IMHABD process, with a net present value (NPV) of 13,647 USD, an internal rate of return (IRR) of 15%, and a 4.95-year payback with a 10-year service life, highlighting its technical efficacy and economic viability for mango drying applications. [ABSTRACT FROM AUTHOR]

Convective drying is one of the most commonly employed preservation techniques for food. However, the use of high temperatures and extended drying times often leads to a reduction in product quality and increased energy consumption. To address these issues, hybrid processes combining convective drying with more efficient methods are frequently employed. This study investigates the convective rotary drying of carrot (cv. Nantes), assisted by microwaves and ultrasound, using a hybrid rotary dryer. In total, four distinct drying programs—comprising one convective and three hybrid approaches—were evaluated. The study assessed drying kinetics, energy consumption, and product quality. The use of ultrasound increased the drying rate by 13%, microwaves by 112%, and microwaves and ultrasound together by 140%. The use of microwaves reduced energy consumption by 30%, whereas ultrasound resulted in a slight increase. All processes resulted in a significant reduction in water activity. Ultrasound decreased the color difference index, while microwaves increased it compared to convective drying. [ABSTRACT FROM AUTHOR]

This study aims to evaluate the electrochemical oxidation of real textile wastewater using boron-doped diamond (BDD) and different titanium-based mixed metal oxide (Ti/MMO) commercial anodes, namely Ti/RuO2-TiO2, Ti/IrO2-Ta2O5, Ti/IrO2-RuO2, and Ti/RuO2/IrO2-Pt. Experiments were conducted in batch mode, with stirring, at different applied current densities. The results showed that BDD attained the best results, followed by Ti/RuO2-TiO2, which achieved total color removal, a chemical oxygen removal of 61% with some mineralization of organic compounds, and a similar specific energy consumption to BDD. The worst performance was observed for Ti/IrO2-Ta2O5, with a specific energy consumption four times superior to BDD due to a negligible organic load removal.

This study addresses the challenge of processing undersized or overripe mangoes by integrating microwave heating with traditional foam-mat drying technique. The study aims at investigating drying kinetics coupled with thin-layer drying modeling and influences of microwave power (300 - 600 W) and hot-air temperature (55 - 75 °C). Among ten drying models, the so-called Midilli equation fitted well with experimental data. Results showed enhanced drying process associated with microwave heating, providing reduced drying time from 600 - 700 min (for conventional hot-air mode) to 30 - 100 min (for microwave-assisted mode). Standard deviations of moisture content and dried foam thickness measured at various points revealed uneven heat distribution when using high microwave energy, evidenced by burnt spots at 600 W. Additionally, foam collapse was observed under the mild process with low microwave powers, possibly due to prolonged drying periods. Response surface methodology demonstrated that microwave power was more important factor, positively affecting effective diffusivity coefficient (Deff) while inversely influencing specific energy consumption (SEC) and color difference (ΔE). Deff value increased from 5.41x10-6 m²·s-1 at 300 W and 55 °C to 18.43x10-6 m²·s-1 at 600 W and 75 °C, confirming enhance drying performance. As assisted with microwave heating, drying foamed mango sample consumed less energy up to 92 %. Optimal drying parameters were determined based on balancing the enhancement of drying performance and color alteration, suggesting drying the thick foamed mango pulp at temperature of 55 °C combined with microwave heating at 520 W, which can be served as a basis for further industrial scale-up. [ABSTRACT FROM AUTHOR]

This article describes elements of the know-how of using carbon electrodes produced using the technology of molding around a rod when smelting silicon metal. Application of our know-how will dramatically increase the competitiveness of silicon metal production. Experts' concerns regarding the use of such electrodes were that such electrodes have a through axial hole. This significantly reduces the mechanical strength of such electrodes, which can presumably lead to problems associated with the breakage of the working side of the electrode, which is immersed in the smelting space of the furnace under the charge layer. Industrial testing of such electrodes was carried out in a 30 MVA furnace of "Tau-Ken Temir" LLP. During testing, we used an approach previously developed by our team for working with a furnace in the process of smelting silicon metal. In particular, we used an interval between top treatments of about 30 min and adhered to the principles of balanced smelting, i.e., provided a balance between the intensity of the uniform supply of the charge into the furnace and the current active electrical power. Industrial testing carried out over four weeks confirmed the stability of the operation of cheaper carbon electrodes with a through axial hole. The recovery of silicon into finished products was also improved to 88–89% and the specific energy consumption was reduced to 11.2–12.1 MWh/t of silicon metal from the initial value 14,752 MWh/t. Thus, we received additional evidence for the effectiveness of our approach in furnace operating compared to an approach based on the ultimate provision of gas and permeability of the furnace top due to excessively intense processing of the top and an uncontrolled, uneven supply of charge to the furnace. [ABSTRACT FROM AUTHOR]

In agriculture, the transformation and drying industries have the most share of energy consumption. The present study aims to optimize the drying process of apple pulp sheets. This process includes checking the energy consumption values and emission of greenhouse gases by the vacuum system in the normal atmosphere (Natm) and controlled atmosphere (Catm) methods. Experiments were conducted at five drying chamber temperatures (i.e., 45, 55, 65, 75, and 85 ℃) and five vacuum pressures (i.e., 40, 50, 60, 70 and 80 kPa). Optimizations were performed using the response surface methodology and the central composite design. The optimum point of apple pulp sheets drying for a gas turbine-oil gas power plant was obtained at a drying temperature of 84.9 ℃ and vacuum pressure of 60.6 kPa. The desirability index was 0.9936 under these conditions. Besides, the optimal value of the response variables, including drying time, total energy consumption (EC), specific energy consumption (SEC), NOX emission, and CO2 emission, were 205 min, 7.65 kWh, 339.02 kWh/kgwater, 1962.94 g/kgwater, and 210,872.40 g/kgwater, respectively. The results showed that in the Catm method, the EC, SEC, NOX, and CO2 from the oil gas turbine power plant were about 19.22%, 37.19%, 37.19%, and 62.72% less than the Natm method, respectively. Therefore, using a vacuum dryer and applying the Catm method in the gas turbine oil of a gas power plant is more economical regarding environmental pollution than the vacuum dryer using the Natm method. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Refrigeration is the property of Journal of Refrigeration Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract Background Reducing energy consumption and greenhouse gas emissions is a crucial issue in the cassava starch processing industry. In this study, the integrated system combining livestock, cassava cultivation and cassava production in the same area leads to both a zero emission goal and economic efficiency, a typical example of an effective agro-industrial symbiosis. A heat exchange/recovery system was applied including the economizer, heat exchanger tank, biogas tank, and boiler. The economizer attached to the boiler’s chimney transfers heat from exhaust gases for pre-heating feed water entering the boiler. The biogas tank recovers energy from the wastewater of starch production and livestock, and the generated biogas was used as fuel for the boiler. Results The energy and exergy efficiency, energy losses, and exergy destruction for the heat recovery system were analyzed. The specific energy consumption was used to evaluate the overall energy efficiency for a cassava starch factory with a capacity of 20 tons/day. The results show that there is a high potential to recycle waste into energy in the cassava starch industry. The total energy saving and reduced greenhouse gas emissions per year of the cassava starch factory were 0.054%/year and 123,564 kgCO2/per year, respectively. Conclusions Cassava starch factories can save energy and reduce emissions when applying a heat recovery system in the integrated agro-industrial system. Excess heat from the production was used for evaporating (removal of) NH3 in wastewater flow from the biogas tank, and for heating the biogas system to enhance the efficiency of methane production. A biochar filter was attached to the economizer for adsorption of released ammonium, and the biochar after adsorption was combined with sludge from the biogas tank to produce a solid biofertilizer.

The efficient and effective operation of trommel screens is essential for the economic and environmental sustainability of mechanical biological treatment (MBT) based solid waste treatment plants. The present study evaluated the performance of four trommel screens (aperture sizes of 80, 32, 16, and 4 mm) being used at the MBT plant of the Municipal Corporation Karnal, India. The performance of trommel screens was evaluated at a fixed speed of rotation and inclination angle. For optimum performance, trommel screens must be operated at a particular range of feed rates with regular cleaning every four hours of operation. The organic recovery achieved by 80 mm and 32 mm aperture size trommel screen was 26.95 % and 95.82 %. The organic quality improvement achieved by 80 mm and 32 mm trommel screens was 122.50 % and 108.89 %. The trommel screen's heating value improvement and energy recovery ranged from 70.68 % to 135.16 % and 28.27 % to 98.74 %, respectively. The oversized fractions of trommel screens of opening sizes 80 mm and 32 mm meet the fuel specification prescribed by the Indian Solid Waste Management Rules 2016. The trommel screen's Specific Energy Consumption (SEC) ranged from 0.63 kWh/tonne to 5.66 kWh/tonne. The learnings and outcomes of this study are helpful for designers, policymakers, operators of solid waste treatment plants, and researchers.

Energy recovery devices can reduce the specific energy consumption and operation cost of reverse osmosis desalination systems, which is an important core energy-saving equipment. In this paper, four combined processes were proposed, including turbine-free single-stage, single-turbine single-stage, dual-turbine two-stage, and single-turbine inter-stage pressurization for reverse osmosis seawater desalination systems, whilst ensuring the same influent flow rate and recovery rate. The whole process routes and equipment selection were also studied. To evaluate the performance of the combined process, the specific energy consumption ratios were analyzed with two different energy consumption ratio analysis methods. The results showed that energy recovery technology can reduce system-specific energy consumption. Optimizing the combination of turbine energy recovery devices, especially the combination process of dual-turbine double-stage desalination system and single-turbine inter-stage pressurized desalination system can significantly reduce the specific energy consumption and overall cost of the system.

Industrial process heat decarbonization through electrification could contribute significantly to climate change mitigation efforts. In the US industry, thermal processes accounted for more than two-thirds of the total final energy demand in 2021. Cross-cutting electrification technologies like industrial heat pumps are suitable for the process heat supply to several industrial unit operations in a sustainable way while also improving overall energy efficiency. This study employs a bottom-up approach to investigate the techno-enviro-economic potentials of deploying high-temperature and steam-generating heat pumps in US textile, pulp and paper, and automotive sectors in different timeframes. The results show that the annual technical potential energy and CO2 savings by electrifying heat supply are 310 PJ (or 36% of the projected energy demand) and 28 MtCO2 (or 71% of the projected CO2 emissions) in 2050 respectively, however, these incur additional costs in each sector (ranging between 5 and 18 $/GJ). The required heating capacity of industrial heat pumps is estimated at 15 GW, which translates roughly into a market of over 6000 heat pump units and an investment volume of $7 billion in the studied processes. Although there may be individual cost-effective opportunities for electrifying heat supply in specific industrial sites, the overall costs are estimated to be high in the three industrial sectors due to the large disparity between electricity and natural gas prices and low heat source temperatures. To overcome the identified techno-economic barriers, comprehensive action plans for different stakeholders are also given. This study provides novel insights that should inform policymakers’ and executives’ decisions about the electrification of the current and future US industrial heat supply in relevant industrial sectors.

Background: Reducing energy consumption and greenhouse gas emissions is a crucial issue in the cassava starch processing industry. In this study, the integrated system combining livestock, cassava cultivation and cassava production in the same area leads to both a zero emission goal and economic efficiency, a typical example of an effective agro-industrial symbiosis. A heat exchange/recovery system was applied including the economizer, heat exchanger tank, biogas tank, and boiler. The economizer attached to the boiler's chimney transfers heat from exhaust gases for pre-heating feed water entering the boiler. The biogas tank recovers energy from the wastewater of starch production and livestock, and the generated biogas was used as fuel for the boiler. Results: The energy and exergy efficiency, energy losses, and exergy destruction for the heat recovery system were analyzed. The specific energy consumption was used to evaluate the overall energy efficiency for a cassava starch factory with a capacity of 20 tons/day. The results show that there is a high potential to recycle waste into energy in the cassava starch industry. The total energy saving and reduced greenhouse gas emissions per year of the cassava starch factory were 0.054%/year and 123,564 kgCO2/per year, respectively. Conclusions: Cassava starch factories can save energy and reduce emissions when applying a heat recovery system in the integrated agro-industrial system. Excess heat from the production was used for evaporating (removal of) NH3 in wastewater flow from the biogas tank, and for heating the biogas system to enhance the efficiency of methane production. A biochar filter was attached to the economizer for adsorption of released ammonium, and the biochar after adsorption was combined with sludge from the biogas tank to produce a solid biofertilizer. [ABSTRACT FROM AUTHOR]

The use of natural additives in pipeline transportation has gained significant attention in recent years due to their potential to enhance the stability and rheology of the suspension. In this study, the dispersing and stabilizing properties of the saponin extracted from the fruits of Sapindus laurifolia are examined in the pipeline transportation of limestone. The physicochemical, morphological, and flow characteristics of limestone samples less than 75 μm are determined. The rheological behaviors of the suspension have been examined by varying the shear rate, solid, and dispersion concentrations. The critical micelle concentration of the dispersant was determined to be 1.8 wt%. In the tested concentration ranges of 40–70%, the Hershel–Bulkley model best matched the data. When the surfactant was added to the suspension, the water's surface tension was lowered, increasing the wettability of the limestone particles and decreasing particle-particle contact. Increases in zeta potential measurements confirmed that the steric component primarily stabilizes limestone water suspension. Finally, the dispersant's economic impact was studied depending on slurry head loss and specific energy consumption. [ABSTRACT FROM AUTHOR]

This study examined the combined effect of torrefaction and microwave absorbers on improving biomass thermochemical characteristics and grindability for heat, power, and value-added products. Camelina straw in two grinds, ground (6.4 mm screen size) and chopped with biochar addition (0%, 10% and 20%), was torrefied in a bench-scale microwave reactor at torrefaction temperatures of 250 °C and 300 °C with residence times of 10, 15 and 20 min under inert conditions and nitrogen-activated. After torrefaction, the geometric mean particle and size distribution, moisture content, ash content, bulk and particle densities were determined, and the grinding performance values of torrefied ground and chopped with and without biochar were determined and compared with the raw camelina straw. The results showed that the geometric diameter decreased after torrefaction in both grinds. The specific energy required for grinding torrefied biomass decreased significantly with biochar addition, longer residence times, and increased torrefaction temperatures. Torrefied ground camelina straw with biochar after grinding had the lowest grinding energy of 34.30 kJ at 300 °C/20 min. The surface morphology by confocal laser scanning microscopy of torrefied camelina straw particles indicated that biochar addition (>10%) and a torrefaction temperature at 250 °C can create profound surface distortion, and beyond 300 °C, colossal surface damage and carbonized weight fractions were produced. [ABSTRACT FROM AUTHOR]

Energy saving and consumption reduction is one of the current important research in the field of green and sustainable manufacturing. Products or components containing variable curvature contouring are widely used in the automotive, medical, aerospace, and mold industries, while there is a lack of methods to model the energy consumption ratio for variable curvature contouring and improve its energy efficiency. A method for modeling the specific energy consumption of variable curvature contouring and energy consumption optimization is proposed for this problem. Firstly, the components of energy consumption in processing of the CNC machine tool machining are analyzed, and the relationship between curvature characteristics and material removal rate is investigated from the geometric perspective. Secondly, orthogonal experiments with different curvatures of straight lines, convex arcs, and concave arcs are designed to collect energy consumption data. Based on the experimental data, the Dueling Deep Q-Network optimization support vector regression (Dueling DQN-SVR) was used to establish the specific energy consumption model considering the curvature. Finally, a multi-objective optimization model is constructed when considering specific energy consumption, efficiency, and quality, and the Pareto solution set is solved using a multi-objective Gray Wolf optimization algorithm (MOGWO). The Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) method was used to select the optimal combination of machining parameters. The experimental results show that the accuracy of the established model is more than 95%. The method improved energy efficiency by more than 7.82% and efficiency by more than 1.128%. These research results are of great theoretical and practical significance for achieving energy-efficient variable curvature contour machining. [ABSTRACT FROM AUTHOR]

This study developed dried shiitake mushrooms through belt-conveyor combined microwave-hot air (MWHAB) drying, comparing it with hot air (HA) drying. MWHAB drying, with microwave powers ranging from 300 W to 600 W at 65 °C, was contrasted with HA drying at the same temperature. Both blanched and unblanched samples were dried to a final moisture content of 11.1% (d.b.). The research evaluated drying kinetics, specific energy consumption (SEC), and various quality aspects, including color, shrinkage, rehydration, texture, and microstructure. Results showed that blanched samples dried with MWHAB at 600 W significantly reduced drying times and SEC by 76.9% and 77.3%, respectively, compared to HA drying. Dried MWHAB products exhibited lower shrinkage and hardness but higher rehydration, larger pore sizes, and void area fraction than HA. Although no significant color differences were observed, MWHAB drying at 600 W yielded lower values for shrinkage and hardness, and higher values for rehydration, void area fraction, and larger pore sizes than other cases. Additionally, unblanched dried samples displayed reduced shrinkage and hardness but increased color values, rehydration, larger pore sizes, and void area fraction compared to blanched samples. Optimal shiitake mushroom production is recommended using unblanched samples dried with MWHAB at 600 W microwave power. [ABSTRACT FROM AUTHOR]

Due to rapid development of cities, number of municipal wastewater treatment plants (WWTP) has faced drastic growth in recent decades. Reviewing the literature indicates that WWTPs in urban areas are one of the essential energy consumers, and it is necessary to evaluate their energy consumption. In Tehran, the capital of Iran, the number of WWTPs has increased to meet the demands of its increasing population. Yet, the energy consumption of these WWTPs in Tehran has not been thoroughly examined. This research aims to measure and provide the specific energy consumption of Tehran WWTPs and bridge the research gap by providing precise measurements for three key performance indicators (KPIs): energy consumption per influent volume (kWh/m³), per population-equivalent (kWh/PE-year), and per kilogram of Chemical Oxygen Demand removed (kWh/kg COD). The South Tehran Wastewater Treatment Plant (STWWTP), the largest WWTP in Tehran, demonstrated highest energy efficiency with consumption rates of 0.21 kWh/m³ for influent volume, 16.75 kWh/PE-year, and 0.48 kWh/kg COD removed. Furthermore, the smallscale WWTPs of Tehran showed a significant variation in specific energy consumption. Zargandeh Wastewater Treatment Plant (ZWWTP) represented the poorest efficiency by consuming 96.34 kWh for each person under its service and 3.66 kWh per kg COD removed. In contrast, Ekbatan Wastewater Treatment Plant (EWWTP), among the small-scale WWTPs, demonstrated great energy efficiency with consumption rates of 33.15 kWh per capita and 0.52 kWh/m³. However, this great variation in energy consumption of Tehran WWTPs needs further investigation, and strategies for improving the energy efficiency of these WWTPs are required. [ABSTRACT FROM AUTHOR]

This study investigates how temperature and forward osmosis (FO) membrane properties, such as water permeability (A), solute permeability (B), and structural parameter (S), affect the specific energy consumption (SEC) of forward osmosis-reverse osmosis system. The results show that further SEC reduction beyond the water permeability of 3 LMH bar-1 is limited owing to high concentration polarization (CP). Increasing S by 10-fold increases FO recovery by 177.6%, causing SEC decreases by 33.6%. However, membrane with smaller S also increases external CP. To reduce SEC, future work should emphasize mixing strategies to reduce external CP. Furthermore, increasing the temperature from 10 to 40 °C can reduce SEC by 14.3%, highlighting the energy-saving potential of temperature-elevated systems. The factorial design indicates that at a lower temperature, increasing A and decreasing S have a more significant impact on reducing SEC. This underlines the importance of developing advanced FO membranes, particularly for lower-temperature processes. [ABSTRACT FROM AUTHOR]

In the current study, four drying methods, namely microwave (MD), vacuum (VD), hot air (HAD), and freeze drying (FD), were compared for drying of Indian borage (Plectranthus amboinicus) leaves for optimum energy consumption and bioactive compounds' retention. Effective moisture diffusivity for MD was about 100 times more than that of HAD and VD. MD at 600 W showed minimum specific energy consumption (4.04 kWh/kg), proving the most suitable drying condition. Moreover, it showed desirable energy values in terms of maximum specific moisture extraction rate (0.265 kg moisture/kWh) and maximum drying efficiency (15.85%). Bioactive compounds' retention in terms of phenols, antioxidants, and flavonoids was better in MD, followed by FD. Mathematical modeling of drying kinetics data revealed proper fitting of three drying models, namely, Aghbashlo, Modified Page‐II, and Page model, for explaining the drying behavior of Indian borage leaves. Multivariate characterization using principal component analysis revealed that FD and MD had a strong effect on bioactive compounds' retention, while VD and HAD showed least effect. Hence, based on optimum energy utilization and bioactive compounds' retention, MD at 600 W was selected for efficient drying of Indian borage leaves. Practical applications: Drying of Indian borage leaves using microwave drying (MD) resulted in quicker drying with retention of bioactive compounds and color of dried leaves. The energy aspects were also favorable for industrial scale‐up. With due consideration to capacity enhancement in MD, it can prove to be a promising source of drying for culinary, medicinal, and aromatic plants. [ABSTRACT FROM AUTHOR]

This study proposes a feasible solution for boil-off gas (BOG) treatment to facilitate NH3 fuel use by ocean-going ships, which is currently considered an alternative fuel for ships. Two systems were designed and analyzed for BOG in IMO Type-A NH3 fuel storage tanks for 14,000 TEU container ships. First, BOG lost inside the storage tank minimized economic losses through the onboard re-liquefaction system. The total energy consumed by the system to process NH3 gas generated in the fuel tank at 232.4 kg/h was 51.9 kW, and the specific energy consumption (SEC) was 0.223 kWh/kg. Second, NH3 was supplied to the direct Low-Pressure Selective Catalytic Reduction (LP-SCR) system to treat marine pollutants generated by combustion engines. The feasible design point was determined by calculating the NH3 feed flow rate using three methodologies. The energy consumed by the direct LP-SCR system was 3.89 and 2.39 kW, and the SEC was 0.0144 at 0.0167 kWh/kg at 100% and 25% load, respectively. The feasibility was indicated via economic analysis. Depending on the life cycle cost, the competitiveness of the re-liquefaction system depends on the price of NH3, where a higher price yields a more economical solution. In conclusion, the direct LP-SCR system has a low overall cost because of its low energy consumption when supplying NH3 and its reduced amount of core equipment. [ABSTRACT FROM AUTHOR]

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At present, iron and steelmaking industry worldwide is going through the transition of decarbonisation to meet its goal of reaching net zero by 2050. In addition, Australian iron and steelmaking industry is facing its own challenge of processing lower grade ores with increasing gangue content. Two major pathways are direct reduction of iron – electric arc furnace pathway (DRI-EAF) and direct reduction of iron – electric smelter-BOF (DRI-electric smelter-BOF) pathway. In the present work, a mass and energy balance model of basic oxygen furnace (BOF) and electric arc furnace (EAF) have been developed using thermodynamic software. The EAF model showed that with 100 wt-% cold DRI, the specific electric energy requirement varied between 514 and 651 kWh/tls whereas in case of hot DRI, it varied between 399 kWh/tls and 510 kWh/tls. As the gangue content increased from 10.7 wt-% to 19.1 wt-%, yield decreased from 88 wt-% to 75.5 wt-% and slag weight increased from about 200 kg/tls to 630 kg/tls. The BOF model showed that the slag produced in a BOF varied between 63 kg/tls and 73 kg/tls for lower to higher grade ores reflecting different hot metal chemistry (P, Mn) coming from different ores. The results indicated that electric smelter-BOF is more compatible to process lower grade ores than EAF where quantity of slag and loss of yield are very high with increasing gangue content. CO2 emissions from H2DRI-EAF and H2DRI-electric smelter-BOF pathway for different types of ores increased with the increasing gangue content. For H2DRI-EAF pathway, as gangue content increases from 10.7 wt-% to 19.1 wt-%, CO2 emission rises from 0.10 t/tls to 0.19 t/tls as more limestone is needed to remove the gangue which also increases the production of CO2. In case of H2DRI-electric smelter-BOF pathway, CO2 emission increases from 0.12 t/tls to 0.19 t/tls with increasing gangue content. CO2 emissions from both pathways are significantly lower than the current BF-BOF pathway. [ABSTRACT FROM AUTHOR]

Drying is an important means to maintain the quality of peanut pods and reduce the risk of mildew. Microwave hot air combined drying is renowned for its efficacy, low-energy consumption, and superior processing quality, rendering it suitable for peanut pod drying. However, its efficacy hinges greatly on various parameters. To enhance drying efficiency and quality, the drying kinetics of peanut pods using microwave hot air combined drying equipment were investigated. Varying microwave power (1.2 kW, 2.4 kW, 3.6 kW), hot air temperature (30 °C, 35 °C, 40 °C, 45 °C), air velocity (0.4 m/s, 0.7 m/s, 1 m/s), and microwave radiation time (4 min, 6 min) were examined. Results indicated a decline in drying time, moisture ratio, and drying rate with increasing microwave power, hot air temperature, air velocity, and microwave radiation time. Peroxide and acid values complied with national standards. The Verma model exhibited optimal fitting. At 45 °C, peanut pod moisture diffusion coefficient was 3.022 × 10−9 m2 s−1, specific energy consumption at 30 °C was 5302 kJ/kg, and thermal efficiency was 42.6 %. The synergistic drying of peanut pods by microwave and hot air has a high moisture diffusion coefficient and thermal efficiency. The kinetic and energy analysis of the drying process can furnish some theoretical foundation for subsequent microwave hot air drying and equipment parameter adjustment.

This study examined the combined effect of torrefaction and microwave absorbers on improving biomass thermochemical characteristics and grindability for heat, power, and value-added products. Camelina straw in two grinds, ground (6.4 mm screen size) and chopped with biochar addition (0%, 10% and 20%), was torrefied in a bench-scale microwave reactor at torrefaction temperatures of 250 °C and 300 °C with residence times of 10, 15 and 20 min under inert conditions and nitrogen-activated. After torrefaction, the geometric mean particle and size distribution, moisture content, ash content, bulk and particle densities were determined, and the grinding performance values of torrefied ground and chopped with and without biochar were determined and compared with the raw camelina straw. The results showed that the geometric diameter decreased after torrefaction in both grinds. The specific energy required for grinding torrefied biomass decreased significantly with biochar addition, longer residence times, and increased torrefaction temperatures. Torrefied ground camelina straw with biochar after grinding had the lowest grinding energy of 34.30 kJ at 300 °C/20 min. The surface morphology by confocal laser scanning microscopy of torrefied camelina straw particles indicated that biochar addition (>10%) and a torrefaction temperature at 250 °C can create profound surface distortion, and beyond 300 °C, colossal surface damage and carbonized weight fractions were produced.

A global manufacturing community is dedicatedly striving to implement the concept of NetZero in precision cutting of difficult-to-machine materials, specifically, Inconel 617 (IN617) with due consideration to environmental protocols. The fast strain hardening issue of the said alloy during conventional processing rationalizes the application of electric discharge machining (EDM). However, EDM has been criticized for its high energy consumption and limited cutting efficiency. Moreover, conventional dielectric (kerosene) employed in EDM has drastic environmental and operator health concerns. To address the abovementioned issues, waste cooking oil (WCO) has been employed in this study which enhances the reusability of resources and minimizes the cost of the dielectric. Making the process sustainable is imperative along with continuously escalating scarcity of engineering resources. Therefore, the potential of shallow and deep cryogenically treated electrodes (SCT and DCT) has been comprehensively examined against nanofilled WCO to achieve the aforementioned objective. Three different concentrations of powder (Cp) and surfactant (Cs) to uplift the machining responses are investigated through a detailed parametric experimental design. Core machining factors such as material removal rate (MRR), surface roughness (SR), and specific energy consumption (SEC) are examined through optical and electron microscopy studies and 3D surface profilometry. Hereafter, machining factors are modelled using the artificial neural network (ANN) technique. An exceptional improvement of 80%, 25.3%, and 75.16% has been achieved in MRR, SR, and SEC respectively using nanopowder-mixed WCO against SCT brass compared to the responses' values obtained against conventionally used kerosene. Furthermore, compared to kerosene, the maximum CO2 reduction of 79.97 ± 11.2% is achieved with WCO. [ABSTRACT FROM AUTHOR]