scholarly journals Energy efficiency of staged reverse osmosis (RO) and closed-circuit reverse osmosis (CCRO) desalination: a model-based comparison

2020 ◽  
Vol 20 (8) ◽  
pp. 3096-3106
Author(s):  
Simeng Li ◽  
Karla Duran ◽  
Saied Delagah ◽  
Joe Mouawad ◽  
Xudong Jia ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Reverse Osmosis ◽  
Specific Energy ◽  
Numerical Models ◽  
Specific Energy Consumption ◽  
Closed Circuit ◽  
Two Stage ◽  
One Stage ◽  
Multi Stage

Abstract Reverse osmosis (RO) technologies have been widely implemented around the world to address the rising severity of freshwater scarcity. As desalination capacity increases, reducing the energy consumption of the RO process per permeate volume (i.e., specific energy consumption) is of particular importance. In this study, numerical models are used to characterize and compare the energy efficiency of one-stage continuous RO, multi-stage continuous RO, and closed-circuit RO (CCRO) processes. The simulated results across a broad range of feed salinity (5,000–50,000 ppm, i.e., 5–50 g kg−1) and recovery (40%–95%) demonstrate that, compared with the most common one-stage continuous RO, two-stage and three-stage continuous RO can reduce the specific energy consumption by up to 40.9% and 53.6%, respectively, while one-stage and two-stage CCRO can lead to 45.0% and 67.5% reduction, respectively. The differences in energy efficiencies of various RO configurations are more salient when desalinating high-salinity feed at a high recovery ratio. From the standpoints of energy saving and capital cost, the simulated results indicate that multi-stage CCRO is an optimal desalination process with great potential for practical implementation.

scholarly journals Batch Reverse Osmosis Desalination Modeling under a Time-Dependent Pressure Profile

Membranes ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 173
Author(s):  
Abdeljalil Chougradi ◽  
François Zaviska ◽  
Ahmed Abed ◽  
Jérôme Harmand ◽  
Jamal-Eddine Jellal ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Reverse Osmosis ◽  
Specific Energy ◽  
Energy Demand ◽  
Specific Energy Consumption ◽  
Pressure Profile ◽  
Recovery Ratio ◽  
Feed Concentration ◽  
Energetic Performance ◽  
Feed Volume

As world demand for clean water increases, reverse osmosis (RO) desalination has emerged as an attractive solution. Continuous RO is the most used desalination technology today. However, a new generation of configurations, working in unsteady-state feed concentration and pressure, have gained more attention recently, including the batch RO process. Our work presents a mathematical modeling for batch RO that offers the possibility of monitoring all variables of the process, including specific energy consumption, as a function of time and the recovery ratio. Validation is achieved by comparison with data from the experimental set-up and an existing model in the literature. Energetic comparison with continuous RO processes confirms that batch RO can be more energy efficient than can continuous RO, especially at a higher recovery ratio. It used, at recovery, 31% less energy for seawater and 19% less energy for brackish water. Modeling also proves that the batch RO process does not have to function under constant flux to deliver good energetic performance. In fact, under a linear pressure profile, batch RO can still deliver better energetic performance than can a continuous configuration. The parameters analysis shows that salinity, pump and energy recovery devices efficiencies are directly linked to the energy demand. While increasing feed volume has a limited effect after a certain volume due to dilution, it also shows, interestingly, a recovery ratio interval in which feed volume does not affect specific energy consumption.

scholarly journals The methodical issues of industrial energy monitoring systems implementation

2020 ◽  
pp. 47-56
Author(s):  
V. Nakhodov ◽  
O. Borychenko ◽  
A. Cherniavskyi
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Monitoring System ◽  
Energy Management ◽  
Specific Energy ◽  
Management System ◽  
Specific Energy Consumption ◽  
Monitoring Systems ◽  
Energy Management System ◽  
Energy Monitoring

Statistics show that energy is one of the highest operating costs in a manufacturing enterprise. So, improving energy efficiency can lead to a significant increase in profits and reduce the impact of the enterprise on the environment. To increase the performance of energy efficiency activities, it is necessary to implement an energy management system. One of the components of this system is energy monitoring, which, in turn, is based on the periodic collection and analysis of data to assess the state of the monitoring objects in terms of energy efficiency. In this paper, the role and place of energy monitoring in the energy management system of an industrial enterprise are noted. The paper proposes the concept of creating energy monitoring system in industrial companies, which is based on the combination of a monitoring system based on specific energy consumption, and usage of group energy characteristics of production facilities. Implementing such energy monitoring systems will allow to conduct operational control of energy efficiency of production facilities by creating individual systems for monitoring energy efficiency, as well as successfully carry out such monitoring at the enterprise and its subdivisions over longer periods of time using specific energy consumption indicators. It also provides general guidelines for conducting energy monitoring. These guidelines were formed based on the results of studying various methods and scientific publications in the field of energy monitoring, as well as on the basis of practical experience in the development and implementation of energy management systems. Particular attention is paid to the issues of processing and analysis of information about the objects of energy monitoring of industrial enterprises. The practical application of the concept of creating energy monitoring systems envisages gradual improvement of the existing monitoring system based on the specific energy consumption, which will be further completely replaced with individual energy efficiency monitoring systems.

Exergy and Energy Analysis, Drying Kinetics and Mathematical Modeling of White Mulberry Drying Process

2014 ◽  
Vol 10 (2) ◽  
pp. 269-280 ◽  
Author(s):  
Hosain Darvishi ◽  
Mohammad Zarein ◽  
Saied Minaei ◽  
Hamid Khafajeh
Keyword(s):  
Mathematical Modeling ◽  
Energy Efficiency ◽  
Energy Consumption ◽  
Moisture Content ◽  
Specific Energy ◽  
Microwave Power ◽  
Specific Energy Consumption ◽  
Drying Kinetics ◽  
Improvement Potential ◽  
White Mulberry

Abstract The energy and exergy analysis, drying characteristics and mathematical modeling of the thin-layer drying kinetics of white mulberry using microwave drying were investigated. Results indicated that values of exergy efficiency (33.63–57.08%) were higher than energy efficiency (31.85–55.56%). Specific energy consumption increased with increasing microwave power while improvement potential decreased. The specific energy consumption and improvement potential varied from 3.97 to 6.73 MJ/kg water and 0.71 to 2.97 MJ/kg water, respectively. Also, energy efficiency decreased with decrease in moisture content and microwave power level. The best exergy and energy aspect was obtained by drying at 100 W microwave power. Drying took place mainly in warming up, constant rate and falling rate periods. The Page model showed the best fit to experimental drying data. Effective diffusivity increased with decreasing moisture content and increasing microwave power. It varied from 1.06 × 10−8 to 3.45 × 10−8 m2/s, with an energy activation of 3.986 W/g.

scholarly journals Specific Energy Consumption/Use (SEC) in Energy Management for Improving Energy Efficiency in Industry: Meaning, Usage and Differences

Energies ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 247 ◽  
Author(s):  
Akvile Lawrence ◽  
Patrik Thollander ◽  
Mariana Andrei ◽  
Magnus Karlsson
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Specific Energy ◽  
Performance Indicator ◽  
Paper Industry ◽  
Specific Energy Consumption ◽  
Lack Of Information ◽  
Depth Analysis ◽  
Industrial Energy ◽  
Industrial Energy Efficiency

Although several research studies have adopted specific energy consumption (SEC) as an indicator of the progress of improved energy efficiency, publications are scarce on critical assessments when using SEC. Given the increasing importance of monitoring improved industrial energy efficiency and the rising popularity of SEC as an energy key performance indicator (e-KPI), an in-depth analysis and problematization on the pros and cons of using SEC would appear to be needed. The aim of this article is to analyse SEC critically in relation to industrial energy efficiency. By using SEC in the pulp and paper industry as an example, the results of this exploratory study show that although SEC is often used as an e-KPI in industry, the comparison is not always straightforward. Challenges emanate from a lack of information about how SEC is calculated. It is likely that SEC is an optimal e-KPI within the same study, when all deployed SECs are calculated in the same way, and with the same underlying assumptions. However, before comparing SEC with other studies, it is recommended that the assumptions on which calculations are based should be scrutinized in order to ensure the validity of the comparisons. The paper remains an important contribution in addition to the available handbooks.

scholarly journals Multi-Stage Method of Milk Powder Production: Energy Costs Analysis

2021 ◽  
Vol 51 (2) ◽  
pp. 395-401
Author(s):  
Vladimir Kharitonov ◽  
Vladimir Asafov ◽  
Pavel Kuznetsov ◽  
Valentina Gabrielova
Keyword(s):  
Energy Consumption ◽  
Specific Energy ◽  
Mass Fraction ◽  
Specific Energy Consumption ◽  
Milk Powder ◽  
Material Balance ◽  
Energy Costs ◽  
Dehydration Process ◽  
Milk Whey ◽  
Multi Stage

Introduction. One of the promising methods in the production of dairy and other food in concentrated, condensed and dry forms is a consistent combination of dehydration methods. The subject of this research relevant now is approaches to the calculation of such processes. The work objective is to analyze the dehydration staging effect on the energy consumption in this process. Study objects and methods. Liquid, concentrated and powdered dairy products: whole and skim milk, milk whey, whole milk substitutes, as well as their dehydration parameters at certain stages. The determination of moisture and solids mass fraction in products was carried out with a standard method. Results and discussion. The feasibility of using a multi-stage dehydration method for the production of various types of powder milk products has been justified. The characteristic boundaries of solids mass fraction at different stages of the process were determined. The material-balance equation made it possible to define the formula for the total specific energy consumption relative to the unit of the final dry product at an arbitrary number of dehydration stages. The paper contains examples of a comparative efficiency assessment of the dehydration process carried out at different stages from the point of view of energy costs of its implementation. Conclusion. The research featured various issues related to the use of dehydration methods in the production of milk powder products. An equation has been drawn up to estimate the specific energy consumption of the multi-stage dehydration process relative to a unit of the final dry product. The use of a multi-stage process allows to effectively reduce the specific energy consumption, as well as to generate new high quality products.

MODERN ENERGY POLICY AND SECTORAL SITUATION OF ENERGY SUPPLY/ENERGY CONSUMPTION IN THE HOUSE FUND OF UKRAINE

2018 ◽  
Author(s):  
Nikolay Tymchenko ◽  
◽  
Nataliia Fialko ◽  
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Energy Policy ◽  
Specific Energy ◽  
Energy Supply ◽  
Residential Buildings ◽  
Specific Energy Consumption

The article analyzes the main trends in the modern energy policy of Ukraine in the field of ensuring the energy efficiency of civilian facilities. The specific energy consumption in the processes of heating/cooling of residential buildings and the sectoral situation of energy supply/energy consumption in Ukraine are analyzed.

ULL AND ENERGY EFFICIENCY ANALYSIS OF NEW ELECTRIC LOCOMOTIVES

2017 ◽  
pp. 70-80
Author(s):  
Alexander Baklanov ◽  
Nikolay Yesin ◽  
Andrey Shilyakov
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Specific Energy ◽  
Performance Indicators ◽  
Linear Regression Analysis ◽  
Practical Importance ◽  
Specific Energy Consumption ◽  
Alternating Current ◽  
Efficiency Improvement ◽  
Passenger Cars

Objective: To study the specificities and parameters of the new, including innovative, freight and passenger electric locomotives, produced for domestic railways in the framework of the program of creating the new locomotives in 2004–2010. To analyze pull and energy efficiency parameters of direct current and alternating current electric locomotives. To estimate the maximum weight of trains and specific energy consumption of electric locomotives. To detect the advantages of new electric locomotives in comparison with those produced earlier. To develop guidelines on efficiency improvement of the new electric locomotives. Methods: Comparative analysis, methods of grade computations, linear regression analysis, power balance method. Results: The main design features and parameters of the new and earlier produced electric locomotives were studied, the former include the power of tractive motors, traction effort, as well as the speed at continuous rating of traction. The parameters of the new and earlier produced electric locomotives were compared. Key performance indicators of electric locomotives were analyzed, such as the maximum mass of a train and specific energy consumption on traction. The comparison of the above-mentioned indicators with performance indicators of earlier produced electric locomotives was given. According to calculation data and statistical data analysis the advantages of new electric locomotives were determined over those produced earlier. High performance of regenerative breaking was shown, specifically new electric locomotives. It was detected that in winter regeneration of electric energy was significantly reduced, in case of regenerative braking of passenger electric locomotives series EP1 with alternating current, as most of energy generated by tractive motors was spent on electric heating circuits of passenger cars. Guidelines on efficiency improvement of new electric locomotives were developed. Practical importance: The conditions in which new electric locomotives would implement the available advantages were determined, compared to those produced earlier. The elaborated offers make it possible to improve pull and energy efficiency of the new electric locomotives in operation.

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