Search

This study proposes the integrated designs of energy systems and a re-liquefaction system for ocean-going LH2 tankers. Five prospective energy systems (Systems A to E) are suggested, using LNG as fuel, and a re-liquefaction system with a Claude cycle is developed. Their economic value, technological feasibility, and environmental impact are evaluated. The re-liquefaction systems' exergy efficiency and specific energy consumption ranges were 26.79–46.27% and 3–7.45 kWh/kg, respectively. The re-liquefaction system in System C is economically feasible up to $2/kg of H2. LCC of the integrated designs shows that System C has the lowest cost of $140 million. The shipping costs for each design are reviewed, and the lowest one is $447/ton of H2 for System C. Although System C CAPEX is the second expensive, it has the highest efficiency. Consequently, System C with the low-pressure engine, SOFC, and the re-liquefaction system is determined to be the optimal one.

This paper firstly proposed using ice abrasive water jets (IAWJs) to slot coal seam to ensure the safe exploitation of coal mines. The performances of IAWJs, pure water jets (PWJs) and conventional abrasive water jets (CAWJs) breaking coal were simulated and compared using the coupled SPH-FEM methodology. The findings indicate that the breaking performance of coal samples subjected to abrasive water jets are more obvious than those of coal samples subjected to PWJs, while the performance achieved by CAWJs is slightly more evident than that by IAWJs. Most of the ice particles transformed into pure water after impacting and then flowed away with the backflow, while many abrasives remained in the coal under CAWJ impact. The specific energy consumption of breaking coal by IAWJs is obviously lower than that consumed by PWJs and CAWJs. Accordingly, it can be inferred that IAWJ is a promising technology in coal slotting applications

The selection of a proper drying method can play a vital role in reducing the energy consumption and the quality of the final product. In this study, three dryers, including conventional refractance window (CRW), solar refractance window (SRW) based on the photovoltaic-thermal system, and hot air (HA) dryers, were used to dry the Aloe vera gel. Experiments were carried out at four levels of temperature (60, 70, 80, and 90 °C) and three levels of thickness (1, 2, and 3 mm) for the puree product. An increase in temperature and a decrease in thickness reduced specific energy consumption, specific heat consumption, specific heat utilization, pollutant emission, and social costs derived from the pollutant. The results showed that the SRW dryer significantly improved the energy and drying parameters compared to the HA method. The pollutant emission and social costs in the SRW dryer were zero, while these values were significant using the CRW and HA dryers. The highest amounts of antioxidant potential, phenol, flavonoids, and glucose were 98.61%, 0.0435%, 0.0103%, and 19.28% (mg/g dry matter), which were obtained at 60 °C and 3 mm thickness using the SRW/CRW dryers. However, these values were 76.69%, 0.0246%, 0.0039%, and 16.31% (mg/g dry matter) using the HA dryer. In general, according to energy consumption and drying parameters, the best experimental results were obtained at temperatures between 70 and 80 °C and a thickness of 2 mm.

Thailand’s ceramic industry is one of the most important industries in the country in terms of export figures. However, production consumes a large amount of energy and raw materials, which causes ...

About 40 % of the forest area in the Russian Federation is occupied by larch trees growing in the southern regions of Eastern Siberia and the Far East, where existing and reconstructed woodworking enterprises are located. In this regard, the use of larch wood in the production of fibrous semi-finished products is an urgent task for the Russian forest complex. As is known, larch wood contains a large number of extractive substances that have a significant impact on the process of its deep chemical processing. Therefore, it can be assumed that the production of wood (mechanical) pulp from larch wood, in particular chemical-thermomechanical pulp (CTMP), will be very effective, but with its own specific features. In this paper, it is proposed to modify the technology by using enzymes – protein catalysts of various reactions. The purpose of this study is to determine the potential of using larch wood enzymatic treatment in CTMP-technology, to evaluate the effect of enzymes on the physical and mechanical parameters of the fiber and the specific energy consumption during refining. Industrial samples of Larix sibirica Ledeb (Pinaceae) wood chips were used to obtain CTMP. Five commercially available enzymatic agents were used to treat wood chips. CTMP was obtained using laboratory equipment that simulates the industrial stages of production. Enzymatic treatment of larch wood has shown an improvement in the technological parameters of CTMP production, namely, a decrease in the specific energy consumption for refining and an increase in the quality of finished products.

Direct sunlight is commonly used to dry fresh seaweed by artisanal farmers in Indonesia due to its low cost and ease of handling. Nevertheless, this method poses some drawbacks such as lengthy duration, weather dependency and quality degradation. The application of microwave technology in food processing has progressed dramatically, including in the drying process. The microwave drying method is more efficient and can shorten the processing time. This study aimed to describe a large-scale microwave dryer (MD) design and performance to assist the fresh seaweed drying process. The design concept applies microwave energy with a volumetric heating feature to accelerate the seaweed drying process without damaging its functional groups. The MD dimensions were 2410 (l) x 270 (w) x 210 (h) mm with a dryer capacity of up to six kilograms, an enlarged cavity and multiple magnetrons. The main components of the MD were cavity, air circulation system, drying system and control system. According to the performance testing, the MD’s optimum performance was at a power level setting of P7 and six kilograms load. At this setting, we obtained a dried seaweed with a moisture ratio of 0.68±0.05, drying rate of 30.29±1.32 g/min, specific energy consumption of 3.96±0.08 MJ/kg H2O and energy efficiency of 58.45±2.65%. The total power of the P7 setting operation required 2.00 kW. Fourier-Transform Infrared (FTIR) spectra showed that the functional groups of the dried seaweed were unaltered.

La presente investigación se desarrolló en las instalaciones del Centro de Investigaciones del Níquel ¨Capitán Alberto Fernández Montes de Oca¨, teniendo como objetivo evaluar el efecto que tiene la sustitución del petróleo aditivo por el carbón bituminoso en el proceso de molienda de las lateritas. En ella se demostró que el índice de Bond se incrementa a medida que aumenta el contenido de carbón bituminoso en la mezcla. Al compararla con la mezcla de petróleo y laterita utilizada en la industria se puede afirmar que utilizando un porcentaje inferior a 4,5 % de carbón bituminoso no se incrementa el consumo energético específico en los molinos, mientras que al utilizar el carbón bituminoso en el rango de 5,0 a 5,5 % se incrementa en 3,0 kW-h/t. Las mezclas preparadas cumplieron con las especificaciones exigidas por el ensayo de Bond, presentando un comportamiento granulométrico con predominio de las partículas gruesas, antes y después de ser sometidas a dicho procedimiento.

The present old standard efficiency motors (SEM) in black tea processing machinery consume large amount of electricity, thus increases the cost of production. Technologically improved high-efficiency motors (HEM) or HEM coupled with variable speed drive (VSD) could be useful to achieve high-energy efficiency. Therefore, a study was conducted with the focus to determine the feasibility of introducing HEM and VSD in withering and rolling machinery of black tea manufacturing. A withering trough and two different capacity rotorvane rollers were selected for the study, and the energy consumption of different treatments was measured, and specific energy consumption, annual bill savings, simple payback period, and potential carbon dioxide emission reduction were calculated. The results showed that introducing HEM or HEM coupled with VSD saves the energy compared to SEM (p

The main aim of this paper is to accelerate the drying process of black ginger in a forced convection mixed mode horizontal solar dryer (FCMHSD) by using two successive air mass flow rates. When the drying rate attains the falling rate period, air mass flow rate has minimal effect on drying rate. To diffuse bound moisture present in the product, air mass flow rate has to be reduced for raising the air temperature in the solar dryer. In this manuscript, two cases were considered for drying; Case – 1 with constant air mass flow rate of 0.062 kg/s and Case – 2 with two successive air mass flow rates of 0.062 kg/s during the initial period of drying and 0.018 kg/s during the falling rate period. The performance of FCMHSD was evaluated in terms of drying time, drying efficiency, specific energy consumption (SEC) and moisture diffusivity. The estimated SECs for Case – 1 and Case – 2 were 1.07 kWh/kg and 0.56 kWh/kg, respectively. A significant improvement in thermal performance and moisture diffusivity were observed when the FCMHSD operated under Case – 2 than under Case – 1. The use of two successive air mass flow rate is a new approach for accelerating the drying process.

The article discusses the specific source materials and energy consumption for the production of basalt heat-insulating material.

Artificial drying method for arabica coffee beans requires a large consumption of electrical energy. Electricity is needed to rotate the blower which functions to circulate hot air to the dryer so that it can evaporate some of the water contained in the coffee beans. Most of the arabica coffee producing areas in Aceh province have not been reached by the electricity network so the use of artificial dryers cannot be used. To overcome this obstacle, the air flow circulation system with chimney effect can be used to drain dry air. The aim of this research is to design a chimney effect hybrid dryer which is heat source from solar and biomass energy, to test the performance of the dryer and compare it with the sun drying method. Parameters observed were temperature, moisture content and specific energy consumption of solar radiation and biomass. Dryer capacity is 5 kg of arabica coffee beans. The results showed that the chimney effect hybrid dryer can be used to dry 5 kg of coffee beans. The drying show that drying temperature on the dryer chamber ranged between 37.3-60.9°C. To reduce the moisture content of coffee beans from 52.5 to 12.8% bb, it was take 16-17 hours, while the sun drying method takes up to 46 hours (6 days). The total specific energy consumption of hybrid dryer was 57.1 MJ/kg of water vapor, while the specific energy consumption of the drying method was 59.4 MJ/kg of water vapor.

The paper presents a technical and economic analysis regarding the sandwich panels with polyurethane insulation layer (PUR) used in cold stores’ construction. The authors determine the optimal thickness of the insulating layer (OIT) corresponding to the 5 climatic zones in Romania. The operating and investment costs for cold and frozen storage in these 5 climatic zones have been assessed. The results obtained from the analysis show that regardless of the climatic zone, the OIT for cold storage is 150 mm and for frozen storage is 180 mm. The investment cost increases by 41% and the expenditure on operating energy decreases by 8.3% for 180 mm for cold storage in comparison to OIT. Moreover, this tendency is maintained as well in the other case of frozen storage, where, by increasing the thickness above OIT at 200 mm the investment cost is increased by 20% and the expenditure in operating energy is decreased by 6.7%. The SEC has an average value of 54.83 kWh·m3/yr for cold storage and 74.55 kWh·m3/yr for frozen storage respectively. The average values obtained in the paper were compared with those presented in the literature and resulted in deviations of about 1.58% for refrigeration, and hence 4.1% for freezing.

Process optimization is a popular strategy to improve efficiency, reduce the energy consumption and total cost of the seawater reverse osmosis (SWRO). Forward osmosis (FO) process with a nanofiltration (NF)-like membrane has emerged as a cost-effective technology for seawater desalination pretreatment, due to its high water permeability and low energy consumption compared to RO-like FO membrane. The present work comprehensively evaluated the potential of using an NF-like FO membrane for SWRO pretreatment and analyzed the feasibility of the NF-like membrane-based FO-NF-RO process for seawater desalination. The performance of the FO-NF-RO integrated process was investigated with MgSO4, Na2SO4, and Mg(CH3COO)2 as draw solute, respectively. Besides, the energy consumption and total cost of the hybrid process were also estimated on the laboratory and large scale. The NF-like membrane-based FO process could effectively remove organic molecules and divalent ions effectively. The hybrid process product water could reach the drinking water standard in China (TDS ≤ 1000 mg/L). When water recovery was 42.0%, the hybrid process could produce freshwater with specific energy consumption of 2.99 kWh/m3 and specific water cost of 0.92 $/m3, which were comparable with the conventional SWRO process. Overall, our study revealed the feasibility of the FO-NF-RO process for seawater desalination.

The research aims to compare the performance (PC) and specific energy consumption (Spc.) of the hammer mill when using the T-hammer against the (traditional) rectangular hammer. A homemade mill with four hammers was used in experiment. 36 treatments: 2 hammer shape x 3 impact area (840, 720 and 960 mm2) x 2 feeding rates (1500 and 3000 g min-1) x 3 replicates, with completely random design. The results showed that there was no significant effect of hammer shape on PC at the feed rate of 3000 g min-1, while there was an effect at the rate of 1500 g min-1. An effect was also found for the impact area on the PC at both feeding rates and on Spc., as an inverse relationship appeared between the impact area and mill productivity at the feed rate 1500 g min-1. The area of 720 mm2 surpassed the area 480 and 960 mm2 at the rate of feeding 3000 g min-1, as it recorded 1215.65 g min-1 compared to 950.65 and 882.65 g min-1, respectively. There is effect of feeding rate on PC and Spc. The traditional hammer is recommended for simplicity of design, manufacture and performance at high feed rates compared to the T-shaped hammer.

An automatic feeder for fish feeding was manufactured and evaluated successively. Feed pellet size, air flow rate and feeder screw speed were the most important factors affecting the performance and efficiency of the automatic feeder. It was tested at 3 sizes of pellets (1, 2 and 3 mm), 3 air flow rates (10, 15 and 20 m3 min−1) and 5 screw speeds (180, 360, 540, 720 and 900 rpm). The automatic feeder productivity, efficiency, specific energy consumption and costs were determined. The obtained results indicated that the automatic feeder productivity increases with increasing feed pellets size, air flow rate and rotational speed of screw treatments under study, the automatic feeder efficiency increased with increasing rotational speed of screw until it reached the highest value at 540 rpm and then remain constant at 720–900 rpm and after that decreased with increasing speed. Meanwhile, the specific energy consumption of automatic feeder decreased with increasing feed pellets size, air flow rate and rotational speed of screw treatments under study. The total cost of using automatic feeder ranged from 0.09 to 0.16 EGP kg−1 ($ = 15.63 EGP) for all treatments under study. This feeder will save time, effort and cost for fish industry.

The global energy crisis and climate warming are becoming more and more serious. How to reduce energy consumption and environmental pollution to achieve low-carbon manufacturing is an urgent proble...

In this study, oil was converted to biodiesel via transesterification reaction under the presence of CaO at the laboratory. This aims to evaluate and compare the influence of Jatropha oil with commercial diesel (CD) fuel on the engine operating characteristics. Secondly, this study is to compare engine performance and temperature characteristics of cooling water and lubricant oil under various engine operating conditions of the test engine fueled by Jatropha oil and CD. The results indicated that the engine torque of the engine running with Jatropha oil dropped from 0.2 kW to 0.3 kW at all speeds and its brake specific fuel consumption (BSFC) increased at almost every speed due to the low heating value and high viscosity of the Jatropha fuel. The BTEs of the engines fuelled with Jatropha oil was 0.3%, 1.0%, 0.6%, 0.7%, 1.1%, 1.6%, and 1.0% smaller than the BTEs of the engine when varied speed from 1000 rpm to 2200 rpm. However, the difference was trivial. Also, Jatropha oil contributed to reducing the oil temperature of lubricant and cooling water.

Current studies show that the extent of the ecological benefits of additive manufacturing (AM) against conventional manufacturing is case-specific. In terms of energy performance, deeper investigations of mechanisms between parameters and energy consumption of AM processes are currently emerging research tasks. Focusing on the fused deposition modeling (FDM) process, we have designed and carried out two-level full factorial experiments for five impact factors: print speed, layer thickness, number of parts, part size, and support structure. Through 32 experiments, the effects of the impact factors on the total and specific energy consumption of FDM are analyzed.

Desalination plants are generally studied with higher operating costs compared to water supply facilities. This study was conducted to reduce the cost of water production and to preserve existing water resources. Therefore, the purpose of this study was to utilize the control valves to increase maximum efficiency, thereby reducing the power of the pumps and operating costs. Specific energy consumption was shown to reduce the process operating power by up to 1.7 times from 6.17 to 3.55 kWh/m3 based on seawater reverse osmosis 60 bar. In addition, the water intake process was divided into pre, inter, and post-according to the use method of blasting, and the water treatment process was divided into pre, inter, and post blending. In order to reduce power consumption, the blending process was combined to operate the facility, which resulted in the reduction of power consumption in the order post > pre-inter> inter blending.

This study presents an analytic assessment method of energy consumption processes that was developed to apply to the energy management systems of hotels. This method has based directly on an exergetic approach and examined energy and environmental performances using energy and exergy analysis with the pre-energy audit. The energy efficiency performance of the hotel was considered for uninsulated (Case I) and insulated (Case II) conditions. The results of the analysis show that energy consumption losses are related to not only the structural features of the buildings but also the operational management of the hotels. Also, the specific energy consumption of Case II is 43,08% higher than the Case I. Exergetic efficiency for insulated and uninsulated conditions were found as 27.31% and16.26%, respectively. At the end of the study, some recommendations on effective energy management and the applications of a hotel were revealed.

The aim of the work was to determine the influence of screw speed and variable amounts of fresh vegetable additives on selected aspects of extrusion-cooking of corn-vegetable blends. Corn grit as a basic component was supplemented with a fresh pulp of beetroot, carrot, leek and onion in amounts of 2.5-10% in the recipe. The extrusion-cooking was carried out using a single-screw extruder in the temperature range 120-145°C and extrudates were formed into directly expanded snacks. Two indicators were measured: the production efficiency (Q) and the specific mechanical energy (SME) consumption. As a result of the findings it was noted that the rotational speed of the extruder’s screw showed a greater impact on both production efficiency and SME as compared to the variable amounts of applied additives. A tendency to increased efficiency and specific mechanical energy consumption was observed along with the increase of screw speed during processing. The highest production efficiency was observed if fresh leek and onion were used as additives and the highest extrusion speed screw was applied. The largest specific energy consumption was noted during the extrusion-cooking of blends containing fresh carrot and onion addition at high screw speed.

Intensification of coal mining from mine seams of 0.55–1.20 m thick requires increasing efficiency of loose coal loading that may be achieved by selecting the optimal parameters of auger operating device of a shearer. The most reliable way to determine effect of the auger parameters on the energy parameters of the shearer operation is experimental research in actual operating conditions. As the subjects of the research, we selected up-to-date UKD400 and UKD200-500 shearers, operating in representative conditions of the Krasny Partizan mine of SE SVERDLOVANTRATSIT and Ternovskaya mine of DTEK PAVLOGRADUGOL PJSC. An adaptive method for specific mining operating conditions is proposed for determining the specific energy consumption of the shearers on material disruption and loading for thin seams in actual operating conditions based on fixing the values of currents of the cutting drive motors. Based on processing of the experimental data, an indicative dependence of the power for rock mass loading on the feed rate and the effective width of the operating device is determined. Increasing the auger effective width results in increasing the loading power and specific energy consumption. At the same time, the higher the shearer feed rate, the greater the growth of the loading power and specific energy consumption. This is due to the beginning of the process of loose rock mass circulation, and the larger the auger effective width, the more intensive the circulation process, and at the lower feed rate of the shearer the process starts. A method is proposed for selecting the auger optimum effective width based on the criteria of minimum specific energy consumption and maximum commercial productivity.

A batch-type open cycle heat pump dryer has been numerically simulated to study the energy and exergy performances using various low-GWP refrigerants (R290, R600, R600a, R32, R152a, R1234yf, R1234z...

A zero brine discharge seawater desalination concept integrating reverse osmosis (RO), electrodialysis (ED) and crystallizer into a single system (REC) is presented. Analytical models were used to optimize parameters and minimize water production costs. Parameters varied were: the ratio of seawater to RO brine in the ED diluate channel, ED current density, ED diluate outlet salinity, electricity and salt prices, and RO recovery by adding high pressure RO (HPRO). Using only RO brine instead of only seawater in the ED diluate channel reduced water production costs by 87% from 27 to 3.5 $/m³ while increasing salt production costs 26% from 135 to 170 $/tonne-salt. The former was best for brine minimization, and the latter for salt production. Optimizing ED current density reduced REC costs by another 14% to 3.0 $/m³ while increasing specific energy consumption 26% to 12.7 kWh[subscript e]/m3, corresponding to a Second Law efficiency of 18%. Adding an HPRO stage was uneconomical as it increased specific costs 21%. A salt price of 104.5 $/tonne-salt will justify the cost of adding an ED-crystallizer. REC systems may be economically feasible in parts of the Middle-East. Producing other products such as Mg(OH)₂ or Br₂ may further improve economics. Keywords: Reverse osmosis; Electrodialysis; Hybrid; Salt production; Brine concentration; Seawater

As the water demand increases continuously, large capacities of desalination plant are added every year to meet freshwater demand. The higher carbon footprint of desalination raises concern on global climate change. The integration of desalination and renewable energy source could mitigate this water-energy nexus. Membrane distillation (MD) is a non-isothermal desalination process in which the low-grade heat is used as the driving force. Many researchers have tried to integrate solar energy and MD for sustainable water desalination. This article presents a comprehensive review of solar MD desalination to understand its current state of development. Solar powered MD systems have been investigated for last few decades. However, its commercialization is very limited due to low flux, high specific energy consumption and large collector area requirement. Further, this review presents the recent developments in MD membrane, innovative MD modules and the importance of optimization, which was able to improve the performance of solar MD.

Horizontal vacuum belt filters are used for continuous solid–liquid separation in a wide variety of industrial processes. Despite the low pressure difference (usually Δp

Cilembu sweet potato are a commodity typical of West Java's Sumedang district which will produce tasty, sweet, legit flavors and honey when burning using an oven. The conversion program of fuel oil to gas indirectly encourages modification of the cilembu sweet potato oven. The aim of this research is to test the performance of gas-fired ovens and observe the characteristics of cilembu during burning. Cilembu sweet potato burning in this study are cilembu sweet potatoes which have been stored for more than ten days, with grade B sizes (100-200 grams / tuber) and grade C (

Minimum and zero liquid discharge (MLD/ZLD) are emerging brine management strategies that attract heightened attention. Although conventional reverse osmosis (RO) can improve the energy efficiency of MLD/ZLD processes, its application is limited by the maximum hydraulic pressure (ΔPmax) that can be applied in current membrane modules. To overcome such limitation, novel RO-based technologies, including osmotically assisted RO (OARO) and low-salt-rejection RO (LSRRO), have been proposed. Herein, we utilize process modeling to systematically compare the energy consumption of OARO and LSRRO for MLD/ZLD applications. Our modeling results show that the specific energy consumption (SEC) of LSRRO is lower (by up to ∼30%) than that of OARO for concentrating moderately saline feed waters ( ∼70,000 mg/L TDS). However, by implementing more stages and/or an elevated ΔPmax, LSRRO has the potential to outperform OARO energetically for treating high-salinity feed waters. Notably, the SEC of both OARO and LSRRO could be 50% lower than that of mechanical vapor compressor, the commonly used brine concentrator in MLD/ZLD applications. We conclude with a discussion on the practicability of OARO and LSRRO based on membrane module availability and capital cost, suggesting that LSRRO could potentially be more feasible than OARO.

Exploitation of lignite in continuous surface mines requires removing masses of overburden, which are hauled to a dumpsite. There are some technological arrangements where the overburden is transported several dozen meters down to a spreader operating on a lower located dumping level. Depending on an angle of a declined transportation route, there is a possibility to convert the potential gravitational energy of conveyed down overburden masses into electric energy. To recover the maximum percentage of stored energy, an energy-effective and fully loaded belt conveyor should work in a generator mode. Due to the implementation of such a solution, a lignite continuous surface mine, which is a great electric energy consumer, can obtain the status of an electricity prosumer and reduce its environmental impact, in particular demonstrating significant savings in primary energy consumption. Though lignite surface mining is phasing out in Europe, the recuperative, overburden conveyors for downhill transport match up the targets of sustainable mining, understood as getting the maximum benefits from the exploited natural resources. According to the analyzed case study, an investment into the installation of regenerative inverters for the electric power supply of the declined overburden conveyor would pay off within 3–4 years.

In 2020, the energy consumption and volumes of treated wastewater in four village wastewater treatment plants WTP (with a capacity below $10,000 m^{3}/$month), were monitored monthly. The acquired data showed that the specific energy consumption at the investigated WTP (depending on the period and location) was between 1.561 and $2.580 kWh/m^{3}$ treated wastewater, the annual averages being between 1.786 and $2.334 kWh/m^{3}$ (depending on WTP). Moreover, the consumption given by the equipment related to the biological treatment lines BgT primarily determines the total energy consumption in the WTP-the average annual values of the BgT share in the total energy consumption of the investigated WTP were between 0.632 and 0.729. These findings conclude that the WTP energy efficiency improvement is possible primarily by streamlining aerobic and anaerobic biological treatments.

Nowadays, the rapidly growing population, climate change, and environment pollution put heavy pressure on fresh water resources. The atmosphere is the immense worldwide and available water source. The Adsorptive Water Harvesting from the Atmosphere (AWHA) method is considered a promising alternative to desalination technologies for remote arid regions. The development of novel adsorbents with advanced water-adsorption properties is a prerequisite for practical realization of this method. Metal–organic frameworks (MOFs) are a novel class of porous crystalline solids that bring a great potential for AWHA due to their extremely high specific surface area, porosity, and tailored adsorption properties. This work addresses MIL-160 as a water adsorbent for AWHA. The water-adsorption equilibrium of MIL-160 was studied by volumetric method, the isosteric heat of adsorption was calculated, and finally, the potential of MIL-160 for AWHA was evaluated for climatic conditions of the deserts of Saudi Arabia, Mongolia, the Sahara, Atacama, and Mojave as reference arid regions. MIL-160 was shown to ensure a maximum specific water productivity of 0.31–0.33 gH2O/gads per cycle. High fractions of water extracted (0.90–0.98) and collected (0.48–0.97) could be achieved at a regeneration temperature of 80 °C with natural cooling of the condenser by ambient air. The specific energy consumption for water production varied from 3.5 to 6.8 kJ/g, which is acceptable if solar heat is used to drive the desorption. The AWHA method employing MIL-160 is a promising way to achieve a fresh water supply in remote arid areas.

Fish feed pelletizing machine was designed and fabricated with the aim to improve on existing local pelletizers; encourage local technology and local fish farmers who may be faced with no power supply. It mainly consists of the hopper, pelletizing chamber, frame, bolts and nuts, screw conveyor, cutting mechanism, pelletizing die plate and power transmission unit with dual operation mode. Performance evaluations of the improved pelletizing machine as well as existing machine were carried out and the results showed that both machines were able to produce pellets with 8 mm average diameter and 10 mm average length. The overall mean values of pelleting capacity, specific energy consumption and efficiency of improved and the existing pelletizing machines were 1.20 kg/min, 0.010 kWh/kg and 97.09%; 0.89 kg/min, 0.014 kWh/kg and 75%, respectively. These imply that the improved pelletizing machine could produce a ton of feeds for a 14-hour daily operation and consume approximately 10 kWh of energy as compared to the existing pelletizing machine that would consume 14 kWh. The capacity of the improved pelletizing machine is quite better than the existing pelletizing machine. The improved pelletizing machine efficiency obtained is quite impressive as only about 2.91% of the feed mix might be lost as compared to 25% lost by the existing pelletizing machine. Therefore, the improved fish feed pelletizing machine is recommended for use by small-scale fish feed mill as the existing pelletizers have comparable higher losses couple with lower efficiency.

Reverse osmosis is the leading technology for desalination of brackish water and seawater, important for solving the growing problems of fresh water supply. Thermal technologies such as multi-effect distillation and multi-stage flash distillation still comprise an important portion of the world’s desalination capacity. They consume substantial amounts of energy, generally obtained from fossil fuels, due to their low efficiency. Hybridization is a strategy that seeks to reduce the weaknesses and enhance the advantages of each element that makes it up. This paper introduces a review of the most recent publications on hybridizations between reverse osmosis and thermal desalination technologies, as well as their integration with renewable energies as a requirement to decarbonize desalination processes. Different configurations provide improvements in key elements of the system to reduce energy consumption, brine production, and contamination, while improving product quality and production rate. A combination of renewable sources and use of energy and water storage systems allow for improving the reliability of hybrid systems.

The authors focus on the process of potash ore production by a mechanized method. They show that currently there are no approved procedures for assessing the performance of heading-and-winning machines operating in the conditions of potash mines. This causes difficulties in determining the field of application of heading-and-winning machines, complicates the search for implicit technical solutions for the modernisation of existing models of mining units, prohibits real-time monitoring of the stability of stope-based technological processes and makes it difficult to assess the performance of the services concerning mining enterprises. The work represents an aggregate assessment of the performance of heading-and-winning machines for potash mines by determining complex indicators describing the technological and technical levels of organising the work in stopes. Such indicators are the coefficients of productivity and energy efficiency, respectively. Experimental studies have been carried out in the conditions of the potash mine of the Verkhnekamskoye potassium-magnesium salt deposit to assess the performance of the latest and most productive Ural-20R heading-and-winning machines manufactured in Russia. Using the above methodological approaches, this paper shows that the unsatisfactory technological performance of the studied machine is due to the low productivity of the mine district transport. The average productivity coefficient was 0.29. At the same time, high values of the energy efficiency coefficient show that the productivity of the machine is on par with design conditions.

The demand for green hydrogen is growing as the increasing production of pure hydrogen can no longer be based on fossil hydrocarbons. As water electrolysis would move from niche to a significant consumer of emission-free electricity, the efficiency of electrolytic gas production, lifetime of water electrolysis systems, and balance in the electricity grid become essential. The operational and investment costs of an industrial-scale alkaline water electrolyzer with four practical rectifier topologies are investigated. The results show thyristor-based rectifiers provide poor quality for the AC and DC sides, which leads to nonoptimal specific energy consumption (SEC) of the water electrolyzer and a notable reactive power component. Transistor-based topologies may offer up to 4.5% lower SEC of the electrolyzer than the conventional 6-pulse thyristor bridge. The reactive power results in additional costs in either investments in compensation equipment or regular allowance costs. An additional DC/DC converter can be installed to improve the power quality for the electrolyzer, but the second conversion stage adds to the system complexity and cost without eliminating reactive power. A modular single-stage rectifier based on insulated-gate bipolar transistor (IGBT) bridges is suggested as an alternative to provide improved power quality for both the electrolyzer and the electricity grid. Post-print / Final draft

The harness of conventional fuels is day by day escalating because of the rise in the number of vehicles running by IC engines. Because of this, pollution is also increasing rapidly and it is very dangerous to our environment. If the same thing continues further there will be a problem of extinction of conventional fuel and also the problem of pollution. One of the best alternativesto this problem is biodiesel and mahua is one of the promising biodiesels which is extracted from the mahua non-edible trees which are abundantly accessible in India. Most of the biodiesels are used up to 15–20% blend percentage and it is also having superior properties than those biodiesels. Cetane number improver such as DTBP is supplemented to it to improve the biodiesel performance. Literature survey provided that the toting up of additive may proliferate the blending percentage of mahua biodiesel. The results divulge that M30 with additives indicated an augmented thermal efficiency by 8–10% and declined specific energy consumption by 9–12% compared to diesel and M30 fuel.

Groundwater depletion is becoming a global problem with increasing populations and industrialization coupled with changing climate and hydrologic cycles. Deep groundwater sources are increasingly being considered for water supply sources as they are readily available on-site and are treated with minimum specific energy consumption. However, these deep groundwater sources are often high in total dissolved solids content requiring additional treatment. This chapter presents an overview and consideration for groundwater desalination. Potential environmental, technological, and management issues associated with desalination of deep groundwater reserves are discussed briefly. Finally, a decision framework tool to assess and determine the need for brackish groundwater desalination plants is presented.

In the present study, the effect of commuting by private cars on energy consumption has been evaluated, corresponding to real-time traffic data. On-road data for this study has been acquired during real-time operation of three sample four wheelers and with varying number of passenger occupancy. Variations in speed-time profile has been obtained with an ATmega microprocessor-based GPS data logger, at a sampling rate of 10 Hz. The relation between passenger occupancy and specific energy consumption of four-wheeled vehicles has been quantified for the city of Kolkata and the survey was extended to a total distance of 3796.32 km. It has been observed that the specific energy consumption for the test vehicles varied within a range of 0.489–3.413 MJ/pkm.

After the successful development and operation of the 6 HAL4e test cells at the Ardal research Centre starting in 2008, Hydro decided in 2015 to build an industrial pilot plant. The site chosen is on Karmoy island in Norway, on the very same, cleaned site where the Karmoy Soderberg plant once operated. The 60-cells plant is called the Karmoy Technology Pilot, or KTP for short. The HAL4e cell development program’s ambition included step improvements in energy consumption and environmental friendliness. These innovations span many aspects of cell technology, environment protection, infrastructure, and operation, like low cell resistivity, PAH-free linings, low-energy cell preheat and start-up, low specific energy consumption, low-anode effect rate and duration, low fluoride emissions, low CO2 emissions, automated cell operations, and many more. This paper summarizes the preparation and start-up activities and also presents some operating results of the first two years of operation.

Microwave drying is attracting increasing attention due to its energy efficiency. A self-developed pilot-scale microwave dryer was used in this study to dry two different common types of sewage sludge, namely mechanically dewatered sewage sludge and composting dewatered sewage sludge, by using two heating modes: constant temperature and constant power modes. The microwave drying behavior, specific energy consumption, average drying rate, energy efficiency, and drying effect were explored considering the influences of microwave output power, initial mass, and heating mode. Results showed that the output power had the largest influence on specific energy consumption, energy efficiency, and drying efficiency, followed by the constant temperature and initial mass. The specific energy consumption of mechanically dewatered sewage sludge decreased by roughly 14%. By contrast, the average drying rate increased by approximately 6%, and the energy efficiency increased by approximately 20% for each 1 kW increase in output power. Meanwhile, composting dewatered sewage sludge displayed drying effects at an output power of 3 kW, and the temperature exceeded 80 °C. The comparison of the two modes suggested that the constant temperature mode was better than the constant power mode considering product quality and operational safety. Compared with six thin-layer drying mathematical models, the Midilli–Kucuk model could provide a good fit for the constant temperature mode. The proposed microwave drying process exhibited effective performance in drying rate. This process also demonstrated considerable application potential for sewage sludge drying.

Belt conveyor (BC) transportation systems are considered to be the most effective for handling large volumes of bulk material. With regards to the rules of sustainable development, the improvement of belt conveyor technology is, in many cases, focused on environmental issues, which include the idea of energy usage optimization. The key issue in an energy-efficient transportation system is reducing the value of specific energy consumption (SEC) by increasing conveyor capacity whilst decreasing belt conveyor motion resistance. The main idea of this paper is to conduct an analysis of the modernization of existing belt conveyor transportation systems operated in open-pit lignite mines, in order to achieve relatively small electric energy consumption for a considered transportation task. The first part of the paper investigates the relationship between a conveyor’s SEC and material flow rate for various conveyor design parameters. Then, based on multi-parameter simulations, an analysis of electric energy consumption for a belt conveyor transportation system is carried out. Finally, an energy-saving, environmentally friendly solution is presented.