Reduction Of Electric Energy Consumption Research Articles

Towards Using MMO Anodes in Zinc Electrorefining: Mn Removal by Simulated Plant Off-Gas

Implementing mixed metal oxide (MMO) anodes in zinc electrowinning is highly desired due to the considerable reduction in electrical energy consumption. However, the presence of manganese in the electrolyte is a major obstacle for implementing MMO anodes in the zinc cell houses. In this work, we explore the possibility of using plant off-gas, containing SO2, to remove manganese. A SO2/air gas mixture with different SO2 and O2 concentrations was therefore used for the oxidative precipitation of manganese. It was shown that the manganese oxidation reaction is highly pH-dependent. Calcium hydroxide was used to control the pH during the process. Different operating parameters, i.e., pH, SO2/air ratio, reaction time, and effect of cobalt as a reaction catalyst, were investigated. Optimal conditions for manganese removal were reported. Under the optimal conditions, the manganese concentration decreased from 1 g L−1 to less than 1 mg L−1 within 30 min. Precipitates were characterized using EDS, XRF, and XPS techniques and showed coprecipitation of manganese, zinc, gypsum, and cobalt.

Study on the Reduction of Electric Energy Consumption in the Process of Preserving Agri-Food Products

The authors present a study on the reduction of electric energy consumption in the process of preserving agri-food products. Refrigeration facilities used to cool various easily perishable agri-food products were examined in order to establish solutions for increasing energy efficiency in the storage process. The proposed solution provides for the combination of the refrigeration installation with step cooling, with the infl ow cooler with fan installed in the outside environment, which during the cold period of the year supplies the installation with artificial cold. The experimental results have shown that this system allows the reduction of approximately 27% of the electric energy consumption consumed annually by the existing installations.

RETRACTED: The hybrid absorption cooling–desalination and reverse osmosis system to boost energy utilization efficiency

The reverse osmosis (RO) process is the most widely used water softening system, which is used due to its high-performance efficiency. However, this method causes damage to the ecosystem by producing concentrated salt water. This research investigated the integration of the newly proposed absorption cooling–desalination (ACD) hybrid system and the reverse osmosis method. In this method, the brine that comes out of the reverse osmosis is introduced to the evaporator of the ACD system for further distillation. This work is a possible solution for the treatment of reverse osmosis output brine, increasing the recovery rate, minimizing the overall cost of operation, and preserving the ecosystem. Also, by the implementation of this novel unit, excessive cold fresh water is created. The results show that the cooling capacity of the ACD system alone is about 0.346 kW with a coefficient of performance (COP) of 0.774, and it can produce 13.887 cubic meters of water per day at a working temperature of 85 degrees Celsius, which can be easily obtained from low-temperature sources. Compared to the reverse osmosis method alone, the combined method of reverse osmosis and ACD unit proposed in this article causes an overall increase in recovery rate (RR) by 72% and a reduction in electrical energy consumption by 49%. Besides, the overall produced water salinity declined by 59% due to the integration of RO and ACD units.

Analysis and improvement of the efficiency of NH3-NaSCN single effect absorption cooling system

This work aims at reinforcing simultaneously the coefficient of performance (COP) and the exergetic coefficient of performance (ECOP), in order to improve the operation of an absorption chiller to be used in tropical areas. It uses a new method based on the determination of variable one-line matrix that allows to find the NH3 mass fraction of NH3-NaSCN solution on each branch of the system.This matrix is obtained by substitution between the empirical formulae of NH3 and NH3-NaSCN from two different approaches, with the aim of making the current model more simple and less complex than those commonly used by other researchers. The approach developed is a direct digital method, easy to implement and allowing to find and understand some hidden functions of the black boxes of several energy simulation softwares, such as the Engineering Solver Equation (EES). The modeling of the system is carried out in Matlab to predict the temperatures and mass flows that can upgrade the system. The purpose is to contribute to the improvement and commissioning of an absorption chiller operating at thermal comfort temperatures in two cities in Cameroon: Douala and Yaoundé. The results show that the temperatures in the generator, condenser and absorber for which the COP and ECOP are maximum are respectively [92°C; 100°C]; 35°C, and [35°C; 40.8°C], and those of the mass flow rates of the refrigerant leaving the generator and condenser are respectively [0.44 kg/s; 0.86 kg/s] and 0.98 kg/s. The evaporator does not show these remarks. The simulation results can be used for thermodynamic optimisation of the cooling capacity (CC) and reduction of electrical energy consumption of the current system.

Stacked Laser-Induced Graphene Joule Heaters for Desalination and Water Recycling

The global scenario of water shortage and pollution has necessitated the use of advanced water treatment and desalination technologies. Solar interfacial evaporation has shown promising results for clean water generation but depends on the sunlight intensity, which changes over time and climatic conditions. Furthermore, the solar-driven interfacial evaporation cannot operate in the dark and is susceptible to salt deposition. Here, we have explored the Joule heating effect in laser-induced graphene (LIG)-based Joule heaters (JHs) for interfacial water evaporation under different applied voltages. The effect of stacking of Joule heaters has been explored and found to give an enhanced evaporation rate with less spatial footprint and energy consumption. The evaporation rate in a single-layer LIG JH reached ∼5 kg·m–2·h–1 under the application of 10 V. The JH area and its stacking effect on evaporation rate, spatial footprint, and energy consumption were investigated. An increase in evaporation rate by seven times and reduction of electrical energy consumption by three times has been demonstrated by three levels of stacking compared to its equivalent triple-area LIG JH. The enhanced performance of the stacking configuration could be due to the enhanced heat transfer from the bottom JH to the upper JH, thermal concentration, and reduced thermal losses to the environment. The single-layer LIG JH also gave ∼2 kg·m–2·h–1 evaporation rate under natural sunlight and environmental conditions, showing potential for solar interfacial evaporation. The JHs also showed excellent resistance to salt deposition with self-salt-cleaning capability under the tested conditions. These compact stacked JH systems could be integrated with renewable energy, which can be operated in the presence and absence of sunlight. Such compact JH systems with a lesser spatial footprint, enhanced evaporation rate, and reduced energy requirement can help in providing constant water evaporation for various applications.

Economic-environmental impacts on reduction of energy consumption in technical high schools during the COVID-19 pandemic: case of Manzanillo, Mexico

A study is presented on the economic and environmental impacts, due to the reduction of electricity consumption in a Technical High School in Manzanillo, Mexico, during the COVID-19 pandemic, as well as the impacts generated by the reduction of student mobility. This research shows an analysis of the reduction of electrical energy consumption, the reduction of monthly economic costs and CO2 emissions in the studied institution, these impacts on student mobility during confinement between November 2019 and October 2021 are also analyzed. Results show electrical energy savings of approximately 60MWh during this period, about 34 TnCO2 and an economic saving of 8654 USD. It has also estimated an economic saving in student mobility of approximately 312,840 USD and a reduction in emissions of the order of 64 TnCO2. This research also suggests the implementation of technologies that use renewable energy sources as a strategy in the face of this health emergency and contributes to raising future scenarios for sustainable energy planning.

Novel compact ion exchange membranes through suppressing reverse permeation for high-efficiency recovery of inorganic acids

Drived by high concentration difference between the dilute chamber and the concentrated chamber, the reverse permeation of acid ions and water seriously weakens the concentration effect of the targeted acids separated from acidic effluents through the electrodialysis process. Based on rational structure optimization of ion exchange membranes, we propose the TWEDMS membrane modules consisting of the compact ion exchange membranes, compared with the TWEDM membrane modules consisting of the loose ion exchange membranes for the recovery of HCl, HNO3, H2SO4 and H3PO4. Due to suppressing the reverse permeation of acid ions and water from the compact membrane structure, the TWEDMS membrane modules can provide higher concentration differences and current efficiencies for the recovery of HCl (2.177 mol L-1 and 39.07%), HNO3 (1.928 mol L-1 and 19.68%) and H2SO4 (1.532 mol L-1 and 40.60%) at 180, 160 and 220 min respectively, reflecting superior separation effects of inorganic acids from acidic effluents. Among the recovery of these inorganic acids by the TWEDMS membrane modules, the recovery of HCl shows the largest concentration difference (2.032 mol L-1) at 160 min in the electrodialysis process, while the recovery of H3PO4 provides the highest current efficiency (48.67%). According to the analysis of electrical energy consumption, the membrane resistance and water permeability coefficient can play an important role in the reduction of electrical energy consumption (for example, from 17.53% of TWEDMS to 15.08% of TWEDM for HCl at 180 min) for the recovery of inorganic acids from acidic effluents.

Financial Viability of a Photovoltaic System: the case of University Hospital at the UFSCar/Brazil

Considering the negative consequences of the excessive use of non-renewable energy and the development of technologies related to photovoltaic energy, the present paper aims to analyze if the photovoltaic systems are economically viable for university hospitals. A photovoltaic system was designed in the parking lot of the University Hospital of the Federal University of São Carlos (UFSCar) and analyzed the financial viability of its installation. As a result, the photovoltaic system is financially viable, with an expected generation of 194.2 MWh in the first year and a payback of 7 years. Thus, this paper contributes to the feasibility of photovoltaic projects in university hospitals and the reduction of electric energy consumption, reducing its operational costs, reducing the emission of pollution, and diversification of the Brazilian energy matrix. Furthermore, the results can be used as a scientific basis for other fields, such as public and private hospitals and clinics.

Methodological analysis for assessing the relation of the energy cost with losses of water – a case study

The rational use of energy is being increasingly encouraged. In some countries, there are even subsidies for industries to adopt energy efficiency measures. One of the sectors with great opportunities for efficiency is sanitation, where a large part of energy consumption refers to pumping stations. The objective of this work is to demonstrate the consumption of electrical energy and possible reduction of electrical energy consumption in a sector of study of the Autonomous Water and Sewage Service (SAAE) of the municipality in the south of Minas Gerais. To determine the measures to be taken to reduce energy costs, it is necessary to perform a system diagnosis. For this, field trials were carried out. The study sector had an average expense of R$ 42,097.44/year due to water losses in the system. When considering only electricity costs, they represent 34.20% of the costs in relation to water losses (R$ 14,395.90/year). The system presented 27.73% of total water losses, an energy consumption of 0.6627 kWh/m³ only for the R3 pumping station and 1.302 kWh/m³ when also considering the Water Collection and Treatment Plant (WTP).

On the reduction of electric energy consumption in electrolysis: A thermodynamic study

Electricity is the major component in the cost of hydrogen production via electrolysis. This study aims to reduce electric energy consumption in electrolysis and replace it with lower cost thermal energy. An idealized thermodynamic analysis of hydrogen production by electrolysis at higher temperatures is presented, with particular emphasis on isolating the work and thermal components of the required energy. There is significant advantage in using thermal energy from another complementary process to overheat the inlet steam to meet this need. The electricity demand for electrolysis, under reasonable conditions, can thus be reduced to 26.63 kWh kg−1. Introducing multiple stages can further reduce this to 25.22 kWh kg−1 and more significantly, greatly reduce the temperature of the thermal energy needed. At lower utilizations, it is possible to reduce the electrical requirement to below 20 kWh kg−1, which is less than half the most aggressive targets for electrolyzer improvements.

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

In order to desalinate the extremely saline water such that produced from the shale oil or non-conventional gas extraction, a hybrid solar humidification-dehumidification system was experimentally studied. The proposed system may be also used to dispose of the brine rejected from the reverse osmosis desalination plant. An efficient design of the dehumidifier was also introduced in this work. This design not only enhances the heat transfer but also achieves low pressure drop. It was found that the utilization of solar reflector with the proposed desalination system saves 16.5% of daily electrical energy consumption. It was also found that the total consumed electrical energy was reduced by 65% when the extremely saline water was used compared to brackish water. This reduction in electrical energy consumption gives more advantage to the current studied system when compared to other desalination methods. In addition, its productivity was not affected by the water salinity. It is also capable of producing 72 kg/day when saline water of temperature 85 °C was used when the system operated at the optimal conditions for only 8 hr/day.

Secure gate: Secure gateways and wireless sensors as enablers for sustainability in production plants

The Internet of Things has reached the industry. Allowing connectivity from production plants to the Internet requires appropriate security mechanisms to provide protection against cyber attackers. In this paper, we propose a security architecture for a gateway connecting sensors and automation components from assembly lines with Internet or cloud based systems. A Trusted Platform Module (TPM) is used for protecting the cryptographic keys used in secure communication protocols and to provide protection against illegitimate firmware manipulation. As proof of concept, we implemented the key protection functionality with a TPM for the Open Platform Communications Unified Architecture protocol. In a field test, gateways have been installed together with wireless sensors in production plants. Two significant results with respect to the sustainability objectives of secure remote production, namely, reduction of chemical waste and reduction of electrical energy consumption have been demonstrated.

Boosting SO2-depolarized electrolysis with anodic HI for efficient and energy-saving hydrogen production

The SO2-depolarized electrolysis (SDE) is a promising method for SO2 capture and hydrogen production. But the SDE is limited by the high overpotential and slow kinetics of anodic SO2 oxidation reaction (SOR). Herein, to boost SDE process, we add hydroiodic acid (HI) to the anolyte and form HI-assisted SO2-depolarized electrolysis (HASDE). The mechanism of HI assisted SOR is explored, the existence of HI reduces the onset potential and impedance, but increases current density and reaction rate of SOR. HI is supposed to change the single-step SOR into three-step reactions, without changing the overall anodic reaction. A HI concentration of less than or equal to 0.02 mol/L and an operating temperature of 50 °C or less are recommendable. The comparison of SDE and HASDE processes indicates that HASDE delivers a lower cell voltage than SDE during continuous constant-current electrolysis, and has negligible effect on cathodic H2 evolution, while it achieves 27.03–48.65% reduction in electric energy consumption compared with SDE. The present work provides an innovative strategy for improving SDE and energy-saving production of value-added chemicals like H2SO4 and H2.

Prospects on integrated electrokinetic systems for decontamination of soil polluted with organic contaminants

Overall, investigations about the utilization of electrokinetic technology alone or in combination with other processes have attracted particular attention in recent years for remediation of soils contaminated with heavy metals and organic compounds. This fact is due to its peculiar benefits together with its capability of operating in a fine and low-permeability matrix. This review aimed to ascertain the most recent developments on the commonly proposed integrated technologies (electrokinetic soil washing, electrokinetics coupled with permeable reactive barriers, electrokinetic-advanced oxidation processes, and bioelectrokinetic remediation), by evaluating the gaps, challenges, and trends of these systems in the last years. Special attention is paid to the current approaches for overcoming the main bottlenecks of electrokinetics concerning scale-up and reduction of electric energy consumption by integration of renewable energies.

Characterization of energy consumption of new piezo actuator system used for hydraulic on/off valves

This paper presents a newly developed four-way digital piezo valve system composed of four high-response on/off piezo valves. The main part of the new on/off piezo valves introduces the piezo actuator system, which can be used instead of conventional solenoids. One of the important aspects related to the energy consumption of hydraulic linear drives is the use of energy-efficient hydraulic valves that require low switching energy and low holding power consumption. The first part of the paper presents the theoretical background of piezo technology, which is very important for understanding the properties of piezoelectric actuators. It is followed by a detailed description of the new piezoelectric actuator system used in on/off valves and four-way digital piezo valve system. The main part presents a thorough experimental analysis of the electrical energy consumption of the new piezoelectric actuator system, which can be used both as an actuator of hydraulic high-response on/off valves as well as an energy-efficient micropositioner. To validate the electrical switching energy and the holding power consumption of the new piezoelectric actuator system, several existing on/off valves were used as reference. The experimental analysis shows a huge reduction of electrical energy consumption when using the new piezo actuator system for hydraulic on/off valve actuation. Especially the holding power consumption in the stationary active state is about 6 times lower compared to other hydraulic on/off valves.

Improvement of Energy Efficiency and Productivity in an Electric Arc Furnace through the Modification of Side-Wall Injector Systems

The energy cost of producing steel in an electric arc furnace (EAF) has a sizable influence on the prices of natural gas and electricity. Therefore, it is important to use these energies efficiently via a tailored oxy-fuel combustion burner and oxygen lance. In this study, an important modification of the side-wall injector system in the EAF at Hyundai Steel Incheon works was implemented to reduce electrical energy consumption and improve productivity. A protruding water-cooled copper jacket, including a newly designed burner, was developed to reduce the distance between the jet nozzle and the molten steel. In addition, the jet angles for the burner and lance were separately set for each scrap melting and refining mode. The modifications led to a reduction in electrical energy consumption of 5 kWh/t and an increase in productivity of approximately 3.1 t/h. Consequently, total energy cost savings of 0.3 USD/t and a corresponding annual cost savings of approximately 224,000 USD/year were achieved.

Implementing multiple-effect distillation and reverse osmosis thermal coupling to improve desalination process performance in combined water and power plants

Cogeneration has recently been an appropriate engineering approach to supply increasing energy demands. The present study demonstrates a significant influence on increase in productivity and reduction of utility consumption of thermal desalination, considering a novel internally coupled multiple-effect distillation and reverse osmosis desalination process in a cogeneration of water and power plant. The proposed power generation unit, consisting of two SGT600 gas turbines as prime movers, two heat recovery steam generators and one back-pressure steam turbine, has been applied. The objective is to propose a modified multiple-effect distillation process, due to availability of sufficient cooling water, provided by reverse osmosis reject water. The basic configuration comprises a hybrid desalination using a dual purpose condenser, results of which showed a 45% reduction in electrical energy consumption of multiple-effect distillation, accompanying a 67% decrease in intake water cost. In modified configuration, condenser temperature decreases from 48 to 45℃, allowing number of effects to increase from 5 to 7. Therefore, produced water rate and gain output ratio of the modified multiple-effect distillation increase by 30% and 31%, respectively, while specific energy consumption decreases by 6%, causing a two-year reduction in cogeneration of water and power plant pay-back period compared to the basic configuration.

Modeling the Process of Heat Treatment of Liquid Products in a Plate Heat Exchanger Using an Integrated Energy-Substituting Installation

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.

KONTRIBUSI PHOTOVOLTAIC PADA BANGUNAN “CARBON NEUTRAL” DALAM PENGURANGAN EMISI CO₂

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.

Modelling and Simulation of Integrated Topology of DC/DC converter for LED Driver Circuit

With the increase in technological advancements and impetus to work for the reduction of electrical energy consumption among different types of consumers, there is a primary need to take into account all forms of energy efficiency improvement methods available for electric and electronic equipment been used. It has been noticed that in commercial lighting, in terms of efficiency light-lamps based on light-emitting diodes(LEDs) are far better as compared to those where traditional high pressure sodium (HPS) lamps which are still in use in major underdeveloped and developing areas worldwide in specifically street lighting. The LED have numerous advantages such as high luminous efficiency, life span and it has no mercury in its composition. Therefore, recently researchers of this area has been setting a goal to utilize LED as a good alternative to save electricity from major parts of this planet. In this paper simulation of LED driver circuit is presented to utilize the 12 V LED lighting strip which has been used in Indian hawkers/small shopkeepers since a long time.