Experimental study of hybrid solar humidification dehumidification system for extremely saline water desalination

This thesis focuses on the electric energy efficiency of single stage double disc refining for production of printing grade mechanical pulp from Norway spruce wood chips. The thesis is based on the hypothesis, that more energy efficiency refining can be attained by balanced increases of wood softening and refining intensity. Five mill scale trials were performed where wood softening and refining intensity was varied by applying or changing the following process parameters and variables:Chip pretreatment/impregnation with waterLow dosages of sodium sulfite (Na2SO3) added to impregnationTemperature and retention time in the atmospheric preheater binRefining temperature (housing pressure)Feeding segment design combined with increased production rateBy combining suitable increases in wood softening and refining intensity, it was possible to reduce the specific electric energy consumption in refining by 15% (~290 kWh per bone dry ton (bdt)) while preserving important pulp properties within ±5%, compared to the standard double disc refining process. This was done by combining chip impregnation, using an addition of 0.36% (on bone dry basis) sodium sulfite, with a new feeding segment design which enabled 25% higher production rate.When using the new feeding segment design at an increased production rate at unchanged wood softening, it led to reduced fiber length and increased sheet light scattering coefficient at certain tensile index, compared with the standard segment design at normal production rate. This is consistent with the effects normally seen when the refining intensity is increasing. The specific electric energy consumption was 8% lower at a tensile index of 43.5 Nm/g (on Rapid Kothen laboratory sheets) compared to refining at lower intensity using the standard segment design at normal production rate.Mechanical chip pretreatment with subsequent water impregnation showed a reduction in specific electric energy consumption of 6% (~120 kWh/bdt). When chip impregnation was applied in a later trial with a milder chip compression, it led to increased wood softening seen as better preserved fiber length and reduced light scattering coefficient. This resulted in a reduction in tensile index at certain specific electric energy consumption when applied with the standard refining condition but to an increase in tensile index when applied with refining at higher intensity using the feeding segment design at higher production rate.An addition of 1.2% sodium sulfite during impregnation led to a sulfonate content of pulps of ~0.28% (as Na2SO3 equivalents, including post sulfonation) and an average increase in tensile index of about 8.3 Nm/g, when compared to unsulfonated pulps at certain specific electric energy consumption. The increase in tensile index correlated with increased delamination and internal fibrillation of fibers (measured by Simon’s staining), which indicate that the increase in tensile index for sulfonated pulps was a result of improved fiber flexibility and collapsibility. The reduction in disc gap at certain specific electric energy consumption in refining due to an increased wood softening after sulfonation may explain the increase in delamination and internal fibrillation for sulfonated pulps. The smaller disc gap probably led to a more intense refining, i.e. loading at higher deformation rates due to a higher degree of deformation in bar crossings.Different temperatures (80 vs. 97°C) and retention times (6 vs. 9 min.) in the atmospheric preheater bin were studied. This showed that the lower temperature and shorter retention time was beneficial for the tensile strength and light scattering of pulp when applying low dosage sodium sulfite pretreatment. This was most likely a result of too high degree of wood softening prior to defibration in the breaker bar zone when combining low dosage sodium sulfite pretreatment with the higher preheating bin temperature at longer retention time.Different refining temperatures (4.6 and 6.4 bar(g) refiner housing pressure) were evaluated both without and with low additions (0.6% and 1.2%) of sodium sulfite. Raising the refining temperature increased tensile index by 3.2 Nm/g and the addition of 1.2% sodium sulfite by 8.6 Nm/g. The combined increase (~12 Nm/g) was similar to the effect of increasing the specific electric energy consumption by 380 kWh/bdt, when comparing pulps at equal tensile index. However, the pulps produced with increased refining temperature and sodium sulfite addition had lower light scattering coefficient at certain tensile index. The combination of increased refining temperature and addition of 0.6% sodium sulfite was interesting and resulted in pulp with higher tensile index, light scattering coefficient and brightness together with lower shives content at certain specific electric energy consumption, compared with pulp produced at the lower refining temperature without addition of sodium sulfite.Finally, an implementation of the technology presented here is discussed in relation to the Braviken mill (Holmen Paper AB, Norrkoping, Sweden) concerning reduction in electric energy consumption and steam recovery. The technology has potential to reduce the electrical energy use by ~100 GWh/year at the Braviken paper mill, where this study was performed.

Introduction. Currently, the issue of reducing electrical energy consumption in the technologies of processing agricultural products, in particular, milk is topical. In large part, these costs are associated with the implementation of heat treatment processes. The reduction of electrical energy consumption can be achieved in several ways, one of which is the development and application of solar-powered installations. In this case, the consumption of traditional electrical energy is significantly reduced, but the manufactures have the task of coordinating the installation parameters and the real production conditions of enterprises. Materials and Methods. The study examined energy consumption in milk processing technologies, plate heat exchanger operation modes and heliocollector performance indicators. The heating temperature of the coolant and the product was determined with an instrument complex that allows registering the temperature values in 8 different control points and transmitting the received signals to the personal computer hard disk. The method for defining the parameters of the plant for preparing the coolant in the technologies of milk processing with the use of a complex energy-substituting unit is proposed. The new technique provides a reduction of electric energy consumption from 30 to 70%. Results. The consumption of electrical energy for thermal processes can be reduced by using solar energy. To solve the problem of optimizing the ratio of product consumption, heating area in the heat exchanger, the area of the solar collectors of the energy-substituting installation, it is recommended to use the obtained graphical dependencies and the formula for determining the area of the solar collectors. Discussion and Conclusion. It is possible to determinate the area of solar collectors of complex energy-substituting installation for real production conditions through using the obtained analytical dependence taking into account the dependence the specified parameter on a temperature mode of heating, the area of a surface of heating in the heat exchanger, and weight of milk being processed per unit of time. The obtained graphical dependencies make it possible to determine the product consumption and heating area for the given heating temperature values.

PurposeTo discuss integration of the rapid prototyping environmental aspects with the primary focus on electrical energy consumption.Design/methodology/approachVarious manufacturing parameters have been tested on three rapid prototyping systems: Thermojet (3DS), FDM 3000 (Stratasys) and EOSINT M250 Xtended (EOS). The objective is to select sets of parameters for reduction of electrical energy consumption. For this, a part is manufactured in several orientations and positions in the chamber of these RP systems. For each test, the electrical power is noted. Finally, certain rules are proposed to minimize this electrical energy consumption during a job.FindingsIt is important to minimize the manufacturing time but there is no general rule for optimization of electrical energy consumption. Each RP system must be tested with energy consumption considerations under the spotlight.Research limitations/implicationsThe work is only based on rapid prototyping processes. The objective is to take into consideration the complete life‐cycle of a rapid prototyped part: manufacturing of raw material as far as reprocessing of waste.Practical implicationsReduction of electrical energy consumption to complete a job.Originality/valueCurrently, environmental aspects are not well studied in rapid prototyping.

This work is part of the scientific research sector concerning the Government of Urban and Territorial Transformations in order to promote efficiency and reduction of energy consumption in urban areas. The contribution proposes a further deepening of the research work already carried out under the project Pon Smart Energy Master by the research group of the Laboratory of Territory, Mobility and Environmental (TeMA Lab) of Department of Civil, Architectural and Environmental Engineering, University of Naples Federico II. The aim is to assist public authorities, that also deal with the Urban Energy Governance, in determining the quantitative distribution of domestic and non-domestic electric energy consumption. Toward this goal, we use the Big Data, the Open Data and the Geographic Information System (GIS) techniques. In particular, this work developed a innovative GIS-based methodology that allows the knowledge, classification and representation of real electric energy consumption at micro scale for the domestic and non-domestic. Also, we validate the GIS-based methodology by an application at the city of Naples. We used the electric energy consumption data of year 2011 were given by Municipality Authority and Italian Revenue Agency. This will allow the identification of the electric energy problems present in the area of analysis in order to plan any intervention strategies. This contribution is divided into three main parts. In the first part, an analysis of the scientific literature is proposed on the theme of the Government of urban and territorial transformations and opportunities arising by Big Data, Open Data and GIS in the reduction of electric energy consumption. The second part explains the theoretical and technical phases that led to the development of the GIS-based methodology. In the last part, the application of the GIS-based methodology at the City of Naples is described.

Mining enterprises are examples of energy-intensive enterprises. At the same time, in the total volume of electric energy consumption, they consume about 80% such as: a crushing and sorting factory, a main drainage system, skip hoisting installations and main ventilation installations. In particular, ventilation plants consume approximately 30% of the total electricity consumption, this fact is due to the fact that according to the technology of underground mining, the iron ore mines are aired around the clock, and the electrical capacities of these plants reach 2 MW.Electromechanical complexes of fan installations, in turn, are equipped with synchronous drive electric motors. In order to regulate the performance of the main ventilation unit, inefficient measures are used: turning fan blades, and opening and turning working flaps. Meanwhile, with an increase in the depth of production of iron ore below 1500 m, the effectiveness of the existing ventilation process of underground workings is complicated, and these measures become even more ineffective.The process of the necessary improvement of ventilation systems in iron ore mines and the development of appropriate energy efficient systems to control the rotational speed of the synchronous drive motor of the main ventilation unit must be carried out in a plane of reach to reduce the electrical energy consumption of these units, in turn, will lead to the desired reduction of electrical energy consumption by iron ore mines at all. One of the real directions to achieve this goal is the creation of high-voltage converters, which will increase the energy efficiency of the electric drive of the main fan systems as a whole. In this study, based on the analysis, the possibility of using a power converter based on a multi-level cascade voltage inverter is considered. The proposed method of controlling and shaping the high-voltage supply voltage of the converter will increase the efficiency of the electromechanical system as a whole, as well as reduce the weight and volume of transistor modules and filter components, in the final form will achieve the desired level of performance of electromechanical complexes and all main fan systems as a whole.The prospect of introducing a controlled electric drive for main ventilation installations in underground mining enterprises is a priori economically viable measure that will significantly reduce power consumption by main ventilation systems, facilitate the start-up of synchronous motors and reduce starting currents. In addition, an adjustable electric drive increases the static efficiency and the range of technological use of the main ventilation systems, and, thereby, further reduces power consumption. Meanwhile, to achieve the desired level of electrical energy efficiency of electrical systems, as the entire complex of the main ventilation systems, it is necessary to develop sufficiently efficient circuits of voltage converters.Ref. 12, fig. 5, tabl. 2

Among all building envelops, windows are typically the weakest barrier to heat ingress. The building energy consumption of any conditioned building located in the tropical country is deeply governed by the amount of heat gain inside the building because heating ventilation and air-conditioning (HVAC) system is a major energy consumer. Hence, it can be easily inferred that the energy consumption of a building can be reduced through judicial selection of window glasses. This paper illustrated the importance of thermal transmittance (U-value) and solar heat gain coefficient (SHGC) value of window glazing in detail and also demonstrated the energy savings potential of various types of commercially available windowpanes. The electric energy savings potential of various types of windowpanes such as tinted, reflective, single glazing, and double glazing glasses have been analyzed through eQUEST energy simulation software for a building, situated in the tropical region of India. Building architectural data and all other information regarding HVAC, lighting, etc. have been collected during the energy audit and trained in the eQUEST simulation for further analysis. The calibration of simulation model has been done using actual monthly electricity consumption data of the case building. This study depicts the percentage decrease in electrical energy consumption due to retrofitting of various commercially available window glasses compared with base building. The study also compares the importance of main two determining factor(s) U and SHGC value behind the judicial selection of proper window glazing.

The formation process of a building from the construction phase up to the use of building require much energy. It triggers the happening of global warming. Although the concept of building sustainability applies from now on, but the effect is considerably less, because it doesn’t concern the energy used that consumes on the construction phase. This scientific article is about the effort of reducing the carbon footprint through the concept of carbon neutral that allows the carbon consumption of building returns to zero point by the CO₂ emission reduction in electrical energy consumption. The method is summative evaluation on the architectural work of The Glaxo Smith Kline Carbon Neutral Laboratories for Sustainable Chemistry at Nottingham University to reviewing the electrical energy consumption from the construction phase to the use of the building. The result of this method is proving the building that use photovoltaic technology, which change the sunlight into electrical energy contributes 60,2% of the total electrical energy needs on the effort of CO₂ emission reduction through the systems which the excess energies produced are as carbon credits for “paying back” the carbon used during the construction phase. Through this building, human, nature and technology can walk in harmony without being second-numbered.

Small air-launched unmanned aerial vehicles (UAVs) face challenges in range and endurance due to their compact size and lightweight design. To address these issues, this paper introduces a multi-phase wind energy harvesting trajectory planning method designed to optimize the onboard electrical energy consumption during rendezvous and formation flight of air-launched fixed-wing swarms. This method strategically manages gravitational potential energy from air-launch deployments and harvests wind energy that aligns with the UAV’s flight speed. We integrate wind energy harvesting strategies for single vehicles with the spatial–temporal coordination of the swarm system. Considering the wind effects into the trajectory planning allows UAVs to enhance their operational capabilities and extend mission duration without changes on the vehicle design. The trajectory planning method is formalized as an optimal control problem (OCP) that ensures spatial–temporal coordination, inter-vehicle collision avoidance, and incorporates a 3-degree of freedom kinematic model of UAVs, extending wind energy harvesting trajectory optimization from an individual UAV to swarm-level applications. The cost function is formulized to comprehensively evaluate electrical energy consumption, endurance, and range. Simulation results demonstrate significant energy savings in both low- and high-altitude mission scenarios. Efficient wind energy utilization can double the maximum formation rendezvous distance and even allow for rendezvous without electrical power consumption when the phase durations are extended reasonably. The subsequent formation flight phase exhibits a maximum endurance increase of 58%. This reduction in electrical energy consumption directly extends the range and endurance of air-launched swarm, thereby enhancing the mission capabilities of the swarm in subsequent flight.

Reduction in electric energy consumption is important for minimizing resources used for sweetpotato propagule production in a closed transplant production system. The objective of this study was to test whether or not an increase in cell volume of a tray can reduce electric energy consumption for sweetpotato (Ipomoea batatas (L.) Lam.) vegetative propagation in a closed transplant production system. Single node cuttings each with one unfolded leaf were used as propagules and grown for 18 days at cell volumes of 20, 40, 60 or 80 mL with the same planting density of 643 m-2 in all treatments (number of cells per tray was 98) . The number of harvestable propagules per stock plant did not differ significantly among cell volumes 6 and 10 days after planting, but increased with increasing cell volume 14 and 18 days after planting. The electric energy consumption per propagule for cell volumes of 20, 40, 60 and 80 mL was 0.54, 0.42, 0.34 and 0.26 MJ, respectively, corresponding to electricity costs of 2.2-2.4, 1.7-1.8, 1.4-1.5 and 1.0-1.1 Japanese Yen, respectively, 18 days after planting. Thus, increasing the cell volume of a tray is a useful method for reducing electric energy consumption per propagule for sweetpotato vegetative propagation in a closed transplant production system.

Electrochemical/Fe3+/peroxymonosulfate system for the degradation of Acid Orange 7 adsorbed on activated carbon fiber cathode.

We investigated the reduction of electrical energy consumption in thepulsed corona discharge process for the removal of nitrogenoxides. Hydrocarbon chemical additives used in the laboratory-scaleexperiment are responsible for the enhancement of the NO conversionthrough the chain reactions of free radicals, such as, R, RCO, RO,and others. Electrical energy consumption per converted NO moleculehas a minimum value of 17 eV when pentanol is injected. When ethyleneand propylene are injected, 30 and 22 eV of electrical energy consumptionare required for the conversion of a NO molecule, respectively. The ratioof the pulse-forming capacitance (Ce) to the reactor capacitance (CR)plays an important role in the energy transfer efficiency to thereactor. The maximum energy transfer efficiency of approximately 72%could be obtained by the pulse-forming capacitance, which is 3.4 timeslarger than the reactor capacitance; the maximum NO conversionefficiency was also observed with the same condition.

In this paper, energy and exergy analysis of an existing steel electric arc furnace (EAF) was performed to estimate the furnace potential for increasing the efficiency and decreasing the electrical energy consumption. The results of analysis show that the energy and exergy efficiencies of the furnace are 56.9% and 40.5%, respectively. Field data show that mass flow rate of hot flue gas is around 10.4 kg/s in average which contains 18.3% and 12.2% of total input energy and exergy, respectively. By using energy of flue gas for preheating the sponge iron, electrical energy consumption of the furnace could be reduced up to 88 GJ which means 21.2% reduction in electrical energy consumption and 13.6% increase in steel production. Also, exergy efficiency improves about 10.8% by using preheating scheme.

Three identically oriented homes were used for the study. Two of the homes were identically constructed using wood frame/stucco construction while the third used a wall of sandwiched Styrofoam in between concrete layers. It was found that the concrete house on the average consumed about 15% less energy for HVAC operation than the wood frame houses. Also the photovoltaic array placed on the roofs of two of the houses indicated a reduction in electrical energy consumption from the grid of about 20% of the HVAC electrical energy consumed. TRACE-700 simulation runs were made on both types of houses to determine the design cooling load for each of the houses and the total consumed electrical energy for each house over the whole year on a monthly basis. It was found that in the summer a 20% reduction of electrical energy for HVAC is predicted due to the use of the concrete house as compared to the wood frame homes. In addition a linear correlation was found to represent reasonably well the variation of the daily kilowatt hour versus the daily degree day value for a typical summer month in the Las Vegas, Nev. valley for all three houses. The slope of that line for the concrete home was about 24% less steep than the line for the wood frame construction confirmation in part theoretical calculations that this wall construction is more energy conserving than the base case.

Monitoring and control systems to minimise the influence of mining plants on environment

The soaking and germination process of rice seeds is the starting point in rice cultivation in cold regions and has a significant effect on grain yield. Efficient techniques for controlling the water temperature in the seed tank are required to enhance germination quality. This paper introduces a fuzzy theory for designing a fuzzy logic-based sliding mode controller (SMC) system for a rice seed soaking and germination device. The proposed system was theoretically and experimentally investigated to determine the efficiency of the soaking temperature-control system. A modified fuzzy SMC based on exponent approaching law is also presented for optimizing the proposed controller. A proportional integral derivative (PID) controller was designed to identify and compare the advantages of the proposed controllers. A comparative study of the computer simulation demonstrates that the performance of fuzzy SMC and modified fuzzy SMC are acceptable, and that both SMCs are superior to the PID controller. Furthermore, compared with the fuzzy SMC system, a reduction in electric energy consumption was observed for the modified fuzzy SMC. Moreover, both SMCs yielded similar soaking qualities.