scholarly journals Looking Beyond Energy Efficiency: An Applied Review of Water Desalination Technologies and an Introduction to Capillary-Driven Desalination

Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 696 ◽  
Author(s):  
Seyedsaeid Ahmadvand ◽  
Behrooz Abbasi ◽  
Babak Azarfar ◽  
Mohammed Elhashimi ◽  
Xiang Zhang ◽  
...  

Most notable emerging water desalination technologies and related publications, as examined by the authors, investigate opportunities to increase energy efficiency of the process. In this paper, the authors reason that improving energy efficiency is only one route to produce more cost-effective potable water with fewer emissions. In fact, the grade of energy that is used to desalinate water plays an equally important role in its economic viability and overall emission reduction. This paper provides a critical review of desalination strategies with emphasis on means of using low-grade energy rather than solely focusing on reaching the thermodynamic energy limit. Herein, it is argued that large-scale commercial desalination technologies have by-and-large reached their engineering potential. They are now mostly limited by the fundamental process design rather than process optimization, which has very limited room for improvement without foundational change to the process itself. The conventional approach toward more energy efficient water desalination is to shift from thermal technologies to reverse osmosis (RO). However, RO suffers from three fundamental issues: (1) it is very sensitive to high-salinity water, (2) it is not suitable for zero liquid discharge and is therefore environmentally challenging, and (3) it is not compatible with low-grade energy. From extensive research and review of existing commercial and lab-scale technologies, the authors propose that a fundamental shift is needed to make water desalination more affordable and economical. Future directions may include novel ideas such as taking advantage of energy localization, surficial/interfacial evaporation, and capillary action. Here, some emerging technologies are discussed along with the viability of incorporating low-grade energy and its economic consequences. Finally, a new process is discussed and characterized for water desalination driven by capillary action. The latter has great significance for using low-grade energy and its substantial potential to generate salinity/blue energy.

2019 ◽  
Vol 9 (6) ◽  
pp. 1049 ◽  
Author(s):  
Saveria Santangelo

Electrospinning is a simple, versatile, cost-effective, and scalable technique for the growth of highly porous nanofibers. These nanostructures, featured by high aspect ratio, may exhibit a large variety of different sizes, morphologies, composition, and physicochemical properties. By proper post-spinning heat treatment(s), self-standing fibrous mats can also be produced. Large surface area and high porosity make electrospun nanomaterials (both fibers and three-dimensional fiber networks) particularly suitable to numerous energy-related applications. Relevant results and recent advances achieved by their use in rechargeable lithium- and sodium-ion batteries, redox flow batteries, metal-air batteries, supercapacitors, reactors for water desalination via capacitive deionization and for hydrogen production by water splitting, as well as nanogenerators for energy harvesting, and textiles for energy saving will be presented and the future prospects for the large-scale application of electrospun nanomaterials will be discussed.


2018 ◽  
Vol 20 ◽  
pp. 86-97
Author(s):  
Jan Slad ◽  
Andreas Pickard ◽  
Frank Strobelt

The transition of energy mix in Europe is placing greater focus on energy efficiency. Lawmakers in some of EU countries have already recognized that combined heat and power generation (cogeneration, CHP) can help increase energy efficiency. Targeted promotion and subsidization have raised the cost-effective profitability of cogeneration plants significantly. But how can the economic value of this investment be maximized?


2021 ◽  
pp. 62-74
Author(s):  
N. Batechko ◽  
◽  
S. Shostak ◽  
R. Bereziuk ◽  
V. Shostak ◽  
...  

The results of the research on the application of a systematic approach to solving energy efficiency problems in Ukraine are presented. The reasons for restraining the level of energy efficiency are highlighted, among which are the hollowing: ineffective policy of incentives to reduce energy consumption; lack of investments and conditions for their attraction; inefficient tariff and price policy in the energy sector of the economy, non-compliance with regulations, programs of various levels and measures. The need to increase the level of energy efficiency in Ukraine is substantiated and a system analysis is proposed to solve this problem. The methodology of systems analysis is implemented using a systems approach, in particular, to the interpretation of the process of energy efficiency development as an open, nonlinear, complex system. As an element of systems analysis, the study uses a multilevel approach, which provides an opportunity to consider the object of study at different hierarchical levels: the international community, state, industry, region and individual. It is noted that in order to successfully develop the progress of energy efficiency in Ukraine, it is necessary to take into account global trends and recent large-scale changes in this area. Examples of progress realization at the state level are given, in particular, implementation of a large number of legal acts, a number of stimulating measures for energy saving, etc. The importance of the sectoral level to increase energy efficiency in Ukraine is indicated. The importance of energy efficiency potential at the regional level is emphasized, which can give a significant boost to its entire economy and significantly improve the lives of the population. The importance of optimizing the process of energy efficiency at the level of various institutions is presented; as one of the options for solving this problem, it is proposed to popularize its benefits both among the population and the individual. The multilevel approach to energy efficiency in Ukraine proposed in the study presupposes an integrated combination of efforts at different levels and a synergistic effect of solving the problem. Key words: energy efficiency, system, multilevel approach


Author(s):  
D. T. Ingersoll ◽  
Z. J. Houghton ◽  
R. Bromm ◽  
C. Desportes

Nuclear energy plants are attractive energy source for large scale water desalination since the thermal energy produced in a nuclear reactor can provide both electricity and steam to desalt water without the production of greenhouse gases. A particularly attractive option is to couple a desalination plant with the new generation of nuclear plant designs: small modular reactors (SMR). This allows regions with smaller electrical grids and limited infrastructure to add new electrical and water capacity in more appropriate increments and allows countries to consider siting plants at a broader range of distributed locations. The NuScale SMR plant design is especially well suited for the co-generation of electricity and desalted water. The enhanced safety, improved affordability, and deployment flexibilities of the NuScale design provide a cost-effective approach to expanding global desalination capacity. Parametric studies have been performed to evaluate technical options for coupling a NuScale plant to a variety of different desalination technologies. An economic comparison of these options was performed for each of the different desalination technologies coupled to an appropriately sized NuScale plant capable of providing sufficient carbon-free electricity and clean water to support a city of 300,000 people.


2001 ◽  
Vol 1 ◽  
pp. 968-975 ◽  
Author(s):  
Otto C. Doering ◽  
Marc Ribaudo ◽  
Fransisco Diaz-Hermelo ◽  
Ralph Heimlich ◽  
Fred Hitzhusen ◽  
...  

Economic analysis can be a guide to determining the level of actions taken to reduce nitrogen (N) losses and reduce environmental risk in a cost-effective manner while also allowing consideration of relative costs of controls to various groups. The biophysical science of N control, especially from nonpoint sources such as agriculture, is not certain. Widespread precise data do not exist for a river basin (or often even for a watershed) that couples management practices and other actions to reduce nonpoint N losses with specific delivery from the basin. The causal relationships are clouded by other factors influencing N flows, such as weather, temperature, and soil characteristics. Even when the science is certain, economic analysis has its own sets of uncertainties and simplifying economic assumptions. The economic analysis of the National Hypoxia Assessment provides an example of economic analysis based on less than complete scientific information that can still provide guidance to policy makers about the economic consequences of alternative approaches. One critical value to policy makers comes from bounding the economic magnitude of the consequences of alternative actions. Another value is the identification of impacts outside the sphere of initial concerns. Such analysis can successfully assess relative impacts of different degrees of control of N losses within the basin as well as outside the basin. It can demonstrate the extent to which costs of control of any one action increase with the intensity of application of control.


Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1885
Author(s):  
Piotr F. Borowski

In the 21st century, it is becoming increasingly clear that human activities and the activities of enterprises affect the environment. Therefore, it is important to learn about the methods in which companies minimize the negative effects of their activities. The article presents the steps taken and innovative actions carried out by enterprises in the energy sector. The article analyzes innovative activities undertaken and implemented by enterprises from the energy sector. The relationships between innovative strategies, including, inter alia, digitization, and Industry 4.0 solutions, in the development of companies and the achieved results concerning sustainable development and environmental impact. Digitization has far exceeded traditional productivity improvement ranges of 3–5% per year, with a clear cost improvement potential of well above 25%. Enterprises on a large scale make attempts to increase energy efficiency by implementing the state-of-the-art innovative technical and technological solutions, which increase reliability and durability (material and mechanical engineering). Digitization of energy companies allows them to reduce operating costs and increases efficiency. With digital advances, the useful life of an energy plant can be increased up to 30%. Advanced technologies, blockchain, and the use of intelligent networks enables the activation of prosumers in the electricity market. Reducing energy consumption in industry and at the same time increasing energy efficiency for which the European Union is fighting in the clean air package for all Europeans have a positive impact on environmental protection, sustainable development, and the implementation of the decarbonization program.


Author(s):  
William H. Avery ◽  
Chih Wu

Systems engineering is a top-down approach to program management and systems procurement. It optimizes the development process by ensuring that the operational, technical, and cost goals (and limitations) of a total proposed system are understood before development begins. The requirements for the “forest” are determined before the features of the “trees” are specified. It makes a basic assumption that a team endeavor under single-system management will be established with authority to define development goals and assign subsystem programs and funding. It recognizes that each system requires a unique management structure that is based on the qualifications of the people and organizations available for the total endeavor. Systems engineering begins with an authoritative request or requirement for a system that would provide new capabilities or would reduce existing problems in a significant technical activity. After personnel and level of effort for a preliminary assessment of the need are identified, the initial effort then involves these steps: 1. A precise definition is prepared of the specific operational need for which the proposed system must provide a solution. For example, this book addresses the present national need for a new energy system that can provide a practical, timely, cost-effective, and nonpolluting alternative to petroleum-based fuels for transportation. The need arises from three factors: a. The perception that an alternative to dependence on petroleum fuels for transportation must be developed to avoid severe disruption of world economies in the early years of the twenty-first century; b. Evidence that combustion of fossil fuels is causing a significant increase in the carbon dioxide content of the atmosphere (if not reduced, this could eventually produce a “greenhouse effect,” leading to large-scale changes in climate and an increase in sea level, with severe economic consequences); and c. The belief that solar energy can be used via OTEC to supply nonpolluting fuel in sufficient quantity, at low enough cost, and in time to become a practical alternative to dwindling or unavailable petroleum supplies. Failure to define the system need with sufficient clarity is a root cause of most system development difficulties.


Membranes ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 246
Author(s):  
Soraya Honarparvar ◽  
Xin Zhang ◽  
Tianyu Chen ◽  
Ashkan Alborzi ◽  
Khurshida Afroz ◽  
...  

Climate change, population growth, and increased industrial activities are exacerbating freshwater scarcity and leading to increased interest in desalination of saline water. Brackish water is an attractive alternative to freshwater due to its low salinity and widespread availability in many water-scarce areas. However, partial or total desalination of brackish water is essential to reach the water quality requirements for a variety of applications. Selection of appropriate technology requires knowledge and understanding of the operational principles, capabilities, and limitations of the available desalination processes. Proper combination of feedwater technology improves the energy efficiency of desalination. In this article, we focus on pressure-driven and electro-driven membrane desalination processes. We review the principles, as well as challenges and recent improvements for reverse osmosis (RO), nanofiltration (NF), electrodialysis (ED), and membrane capacitive deionization (MCDI). RO is the dominant membrane process for large-scale desalination of brackish water with higher salinity, while ED and MCDI are energy-efficient for lower salinity ranges. Selective removal of multivalent components makes NF an excellent option for water softening. Brackish water desalination with membrane processes faces a series of challenges. Membrane fouling and scaling are the common issues associated with these processes, resulting in a reduction in their water recovery and energy efficiency. To overcome such adverse effects, many efforts have been dedicated toward development of pre-treatment steps, surface modification of membranes, use of anti-scalant, and modification of operational conditions. However, the effectiveness of these approaches depends on the fouling propensity of the feed water. In addition to the fouling and scaling, each process may face other challenges depending on their state of development and maturity. This review provides recent advances in the material, architecture, and operation of these processes that can assist in the selection and design of technologies for particular applications. The active research directions to improve the performance of these processes are also identified. The review shows that technologies that are tunable and particularly efficient for partial desalination such as ED and MCDI are increasingly competitive with traditional RO processes. Development of cost-effective ion exchange membranes with high chemical and mechanical stability can further improve the economy of desalination with electro-membrane processes and advance their future applications.


Author(s):  
Paul Torcellini ◽  
Shanti Pless ◽  
Chad Lobato ◽  
Tom Hootman

Until recently, large-scale, cost-effective net-zero energy buildings (NZEBs) were thought to lie decades in the future. However, ongoing work at the National Renewable Energy Laboratory (NREL) indicates that NZEB status is both achievable and repeatable today. This paper presents a definition framework for classifying NZEBs and a real-life example that demonstrates how a large-scale office building can cost-effectively achieve net-zero energy. The vision of NZEBs is compelling. In theory, these highly energy-efficient buildings will produce, during a typical year, enough renewable energy to offset the energy they consume from the grid. The NREL NZEB definition framework classifies NZEBs according to the criteria being used to judge net-zero status and the way renewable energy is supplied to achieve that status. We use the new U.S. Department of Energy/NREL 220,000-ft2 Research Support Facilities (RSF) building to illustrate why a clear picture of NZEB definitions is important and how the framework provides a methodology for creating a cost-effective NZEB. The RSF, scheduled to open in June 2010, includes contractual commitments to deliver a Leadership in Energy Efficiency and Design (LEED) Platinum Rating, an energy use intensity of 25 kBtu/ft2 (half that of a typical LEED Platinum office building), and net-zero energy status. We will discuss the analysis method and cost tradeoffs that were performed throughout the design and build phases to meet these commitments and maintain construction costs at $259/ft2. We will discuss ways to achieve large-scale, replicable NZEB performance. Many passive and renewable energy strategies are utilized, including full daylighting, high-performance lighting, natural ventilation through operable windows, thermal mass, transpired solar collectors, radiant heating and cooling, and workstation configurations allow for maximum daylighting. This paper was prepared by the client and design teams, including Paul Torcellini, PhD, PE, Commercial Building Research Group Manager with NREL; Shanti Pless and Chad Lobato, Building Energy Efficiency Research Engineers with NREL; David Okada, PE, LEED AP, Associate with Stantec; and Tom Hootman, AIA, LEED AP, Director of Sustainability with RNL.


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