Thermodynamic efficiencies and GHG emissions of alternative desalination processes

2010 ◽  
Vol 10 (3) ◽  
pp. 416-427 ◽  
Author(s):  
R. Kempton ◽  
D. Maccioni ◽  
S. M. Mrayed ◽  
G. Leslie
Keyword(s):  
Carbon Dioxide Emissions ◽  
Energy Demand ◽  
Large Scale ◽  
Waste Heat ◽  
Ghg Emissions ◽  
Membrane Distillation ◽  
Thermodynamic Efficiency ◽  
Stream Data ◽  
Produce Water ◽  
Flash Distillation

Three alternative approaches to desalinating seawater were evaluated with respect to their thermodynamic efficiencies and greenhouse-gas emissions. The technologies considered were multistage flash distillation (MSF), reverse osmosis (RO), and membrane distillation (MD). The analysis was based on published stream data from large-scale operational MSF and RO facilities and experimental-scale data for the MD process. RO was found to be the most exergy-efficient (30.1%) followed by MD (14.27%) and MSF (7.73%). RO and MD required less power consumption to produce water (3.29 kWh/m3 and 5.9 kWh/m3, respectively) compared to MSF which had a much higher energy demand (16.7 kWh/m3). Similar results were obtained when comparing equivalent carbon dioxide emissions from each process; MD and RO accounted for 5.22 and 2.91 kg CO2eq/m3, respectively, whereas MSF generated three to four times that amount. The results indicate that MD has potential as a commercially viable technique for seawater desalination provided a source of waste heat is available. This study provides an overview of the use of thermodynamic efficiency analysis to evaluate desalination processes and provides insight into where energy may be saved with developed desalination processes and areas of research for emerging desalination techniques.

scholarly journals Carbon Handprint: Potential Climate Benefits of a Novel Liquid-Cooled Base Station with Waste Heat Reuse

Energies ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4452
Author(s):  
Heli Kasurinen ◽  
Saija Vatanen ◽  
Kaisa Grönman ◽  
Tiina Pajula ◽  
Laura Lakanen ◽  
...  
Keyword(s):  
Large Scale ◽  
Energy Savings ◽  
Waste Heat ◽  
Research Question ◽  
Ghg Emissions ◽  
Base Station ◽  
Total Carbon ◽  
Electrical Heating ◽  
Waste Heat Reuse ◽  
And Function

The novel life cycle assessment (LCA)-based carbon handprint indicator represents a potential carbon footprint reduction that producers/products create for customers who use the(ir) product instead of a baseline product. The research question is how to consider a situation in which multiple customers use a product for different purposes to provide a carbon handprint quantification and the associated communication. The study further provides new insight into the greenhouse gas (GHG) emissions reduction potential within the mobile telecommunications and energy sectors. The carbon handprint of a novel Finnish liquid-cooled base station technology is quantified. The liquid-cooled base station provides a telecommunications service and waste heat that is recoverable through the cooling liquid for heating purposes. The baseline solutions are an air-cooled base station, and district and electrical heating. The liquid-cooled base station creates a carbon handprint, both through energy savings in telecommunications and additional waste heat reuse, replacing other energy production methods. A large-scale climate change mitigation potential through a liquid-cooled base station expansion could be significant. Different supply chain operators’ contributions to the total carbon handprint could be terminologically distinguished in communications to emphasize their roles in a shared handprint. The handprint should be transparently communicated for each customer and function.

scholarly journals Environmental Sustainability of Niobium Recycling: The Case of the Automotive Industry

Recycling ◽  
2019 ◽  
Vol 4 (1) ◽  
pp. 5 ◽  
Author(s):  
Saeed Rahimpour Golroudbary ◽  
Nikita Krekhovetckii ◽  
Mohammad El Wali ◽  
Andrzej Kraslawski
Keyword(s):  
Supply Chain ◽  
Environmental Impact ◽  
Primary Production ◽  
Automotive Industry ◽  
Secondary Production ◽  
Energy Demand ◽  
Large Scale ◽  
Ghg Emissions ◽  
Critical Metals ◽  
Gas Emissions

The recycling of scrap is one of the common approaches aiming at reduction of mining-based production of critical metals and mitigation of their supply risk as well as processing-related environmental impact. The number of currently available end-of-life vehicles (ELVs) indicates—significant potential for critical metals recycling, especially niobium (Nb). Therefore, the quantification of environmental impact of niobium recovery starts to be an important issue in assessment of sustainability of large-scale recycling processes. In this paper, we assess energy consumption and greenhouse gas (GHG) emissions in individual stages of niobium supply chain in the automotive industry over the period 2010–2050. The different stages including mining, production and recycling are analyzed using dynamic simulation. The results show the majority of the consumed energy (45% of energy demand in niobium supply chain) is used in the primary production stage. This stage also contributes to 72% of total gas emissions of supply chain over the period 2010–2050. Mining of niobium consumes up to 36% of energy and generates ca. 21% of GHG emissions. While, in recycling stage, the secondary production of niobium requires 19% of supply chain energy and generates 7% of gas emissions. The detailed calculations show that recycling of niobium could save around 133–161 m GJ energy between 2010 and 2050. The recycling would also contribute to the reduction of 44–53 mt CO2-eq in the same period. It shows around 18% reduction of annual emissions between 2010 and 2050 thanks to reuse of niobium in secondary production rather than primary production.

The impact of storage conditions on heat losses of HT-ATES systems

2021 ◽  
Author(s):  
Stijn Beernink ◽  
Martin Bloemendal ◽  
Niels Hartog
Keyword(s):  
Large Scale ◽  
Energy Use ◽  
Waste Heat ◽  
Ghg Emissions ◽  
Storage Conditions ◽  
Heat Losses ◽  
Transport Processes ◽  
Heating And Cooling ◽  
Wide Range ◽  
The Impact

<p>Heating and cooling is responsible for about 50% of the European total energy use. Therefore, renewable sources of heat are needed to reduce GHG emissions (e.g. solar, geothermal, waste-heat). Due to a temporal and spatial mismatch between availability and demand of heat, large scale heat storage facilities are needed. High Temperature Aquifer Thermal Energy Storage (HT-ATES) systems are one of the cheapest and most adequate ways to store large amounts of sensible heat. Regular/Low-T ATES systems are considered a proven technology with currently more than 3 000 systems operable world-wide. However, at higher storage temperatures (e.g. 40-100 °C) temperature dependent water properties (density, viscosity) more strongly affect physical processes, resulting in higher and unpredictable heat losses. While first applications and research on this subject started more than 50 years ago, many uncertainties still remain. In this research we study the (hydrogeological) storage conditions that affect the heat losses of HT-ATES systems. Numerical simulations of a wide range of storage conditions, are done to obtain generic insights in the performance of HT-ATES systems. These insights allow to identify which heat transport processes dominate in contribution to heat losses. Results show that conduction always contributes to heat losses for HT-ATES systems and relate to geometric storage conditions. While buoyancy flow (free convection) may also contribute considerable to heat losses under specific conditions.</p>

scholarly journals Treatment Technologies for Cooling Water Blowdown: A Critical Review

2021 ◽  
Vol 14 (1) ◽  
pp. 376
Author(s):  
Mariam Soliman ◽  
Fadwa Eljack ◽  
Monzure-Khoda Kazi ◽  
Fares Almomani ◽  
Elalim Ahmed ◽  
...  
Keyword(s):  
Energy Demand ◽  
Large Scale ◽  
Wastewater Treatment Plants ◽  
Water Discharge ◽  
Cooling Water ◽  
High Energy ◽  
Membrane Distillation ◽  
Gulf States ◽  
Treatment Technologies ◽  
High Concentrations

Cooling water blowdown (CWBD) generated from different industries and district cooling facilities contains high concentrations of various chemicals (e.g., scale and corrosion inhibitors) and pollutants. These contaminants in CWBD streams deem them unsuitable for discharge into surface water and some wastewater treatment plants. The pollutants present in CWBD, their sources, and the corresponding impacts on the ecosystem are discussed. The international and regional (Gulf states) policies and regulations related to contaminated water discharge standards into water bodies are examined. This paper presents a comprehensive review of the existing and emerging water treatment technologies for the treatment of CWBD. The study presents a comparison between the membrane (membrane distillation (MD), reverse osmosis (RO), nanofiltration (NF), and vibratory shear enhanced membrane process (VSEP)) and nonmembrane-based (electrocoagulation (EC), ballasted sand flocculation (BSF), and electrodialysis (ED)) technologies on the basis of performance, cost, and limitations, along with other factors. Results from the literature revealed that EC and VSEP technologies generate high treatment performance (EC~99.54% reduction in terms of silica ions) compared to other processes (membrane UF with reduction of 65% of colloidal silica). However, the high energy demand of these processes (EC~0.18–3.05 kWh/m3 and VSEP~2.1 kWh/m3) limit their large-scale applications unless connected with renewable sources of energy.

scholarly journals Sustainable Energy-Related Infrastructure Development in the Mekong Subregion: Key Drivers and Policy Implications

2021 ◽  
Vol 13 (10) ◽  
pp. 5720
Author(s):  
Han Phoumin ◽  
Sopheak Meas ◽  
Hatda Pich An
Keyword(s):  
Carbon Dioxide Emissions ◽  
Energy Demand ◽  
Power Plants ◽  
Policy Implications ◽  
Infrastructure Investment ◽  
Infrastructure Development ◽  
Low Carbon ◽  
Energy Access ◽  
Low Carbon Economy ◽  
The One

Many players have supported infrastructure development in the Mekong Subregion, bridging the missing links in Southeast Asia. While the influx of energy-related infrastructure development investments to the region has improved the livelihoods of millions of people on the one hand, it has brought about a myriad of challenges to the wider region in guiding investments for quality infrastructure and for promoting a low-carbon economy, and energy access and affordability, on the other hand. Besides reviewing key regional initiatives for infrastructure investment and development, this paper examines energy demand and supply, and forecasts energy consumption in the subregion during 2017–2050 using energy modeling scenario analysis. The study found that to satisfy growing energy demand in the subregion, huge power generation infrastructure investment, estimated at around USD 190 billion–220 billion, is necessary between 2017 and 2050 and that such an investment will need to be guided by appropriate policy. We argue that without redesigning energy policy towards high-quality energy infrastructure, it is very likely that the increasing use of coal upon which the region greatly depends will lead to the widespread construction of coal-fired power plants, which could result in increased greenhouse gas and carbon dioxide emissions.

scholarly journals Review of Cryogenic Carbon Capture Innovations and Their Potential Applications

2021 ◽  
Vol 7 (3) ◽  
pp. 58
Author(s):  
Carolina Font-Palma ◽  
David Cann ◽  
Chinonyelum Udemu
Keyword(s):  
Carbon Dioxide Emissions ◽  
Carbon Capture ◽  
Large Scale ◽  
Carbon Capture And Storage ◽  
Technological Readiness ◽  
Cryogenic Carbon Capture ◽  
Potential Applications ◽  
Air Capture ◽  
Reduce Carbon Dioxide ◽  
Co2 Recovery

Our ever-increasing interest in economic growth is leading the way to the decline of natural resources, the detriment of air quality, and is fostering climate change. One potential solution to reduce carbon dioxide emissions from industrial emitters is the exploitation of carbon capture and storage (CCS). Among the various CO2 separation technologies, cryogenic carbon capture (CCC) could emerge by offering high CO2 recovery rates and purity levels. This review covers the different CCC methods that are being developed, their benefits, and the current challenges deterring their commercialisation. It also offers an appraisal for selected feasible small- and large-scale CCC applications, including blue hydrogen production and direct air capture. This work considers their technological readiness for CCC deployment and acknowledges competing technologies and ends by providing some insights into future directions related to the R&D for CCC systems.

scholarly journals 2D Nanomaterials for Effective Energy Scavenging

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Md Al Mahadi Hasan ◽  
Yuanhao Wang ◽  
Chris R. Bowen ◽  
Ya Yang
Keyword(s):  
Large Scale ◽  
Waste Heat ◽  
Material Selection ◽  
Power Supplies ◽  
Small Scale ◽  
Energy Scavenging ◽  
Power Sources ◽  
Practical Applications ◽  
2D Nanomaterials ◽  
Self Powered

AbstractThe development of a nation is deeply related to its energy consumption. 2D nanomaterials have become a spotlight for energy harvesting applications from the small-scale of low-power electronics to a large-scale for industry-level applications, such as self-powered sensor devices, environmental monitoring, and large-scale power generation. Scientists from around the world are working to utilize their engrossing properties to overcome the challenges in material selection and fabrication technologies for compact energy scavenging devices to replace batteries and traditional power sources. In this review, the variety of techniques for scavenging energies from sustainable sources such as solar, air, waste heat, and surrounding mechanical forces are discussed that exploit the fascinating properties of 2D nanomaterials. In addition, practical applications of these fabricated power generating devices and their performance as an alternative to conventional power supplies are discussed with the future pertinence to solve the energy problems in various fields and applications.

scholarly journals Greenhouse Gas Balance of Sphagnum Farming on Highly Decomposed Peat at Former Peat Extraction Sites

Ecosystems ◽  
2021 ◽  
Author(s):  
Jan Oestmann ◽  
Bärbel Tiemeyer ◽  
Dominik Düvel ◽  
Amanda Grobe ◽  
Ullrich Dettmann
Keyword(s):  
Water Management ◽  
Drip Irrigation ◽  
Large Scale ◽  
Ghg Emissions ◽  
The Other ◽  
Ghg Mitigation ◽  
Greenhouse Gas Balance ◽  
Peat Extraction ◽  
Water Tables ◽  
Mitigation Potentials

AbstractFor two years, we quantified the exchange of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) at two different large-scale Sphagnum farming sites. At both, peat extraction left a shallow layer of highly decomposed peat and low hydraulic conductivities. One site was characterized by preceding multi-annual inundation and irrigated by ditches, while the other one was inoculated directly after peat extraction and irrigated by ditches and drip irrigation. Further, GHG emissions from an irrigation polder and the effect of harvesting Sphagnum donor material at a near-natural reference site were determined. GHG mitigation potentials lag behind the results of less decomposed sites, although our results were also affected by the extraordinary hot and dry summer 2018. CO2 exchanges ranged between -0.6 and 2.2 t CO2-C ha−1 y−1 and were mainly influenced by low water table depths. CH4 emissions were low with the exception of plots with higher Eriophorum covers, while fluctuating water tables and poorly developing plant covers led to considerable N2O emissions at the ditch irrigation site. The removal of the upper vegetation at the near-natural site resulted in increased CH4 emissions and, on average, lowered CO2 emissions. Overall, best plant growth and lowest GHG emissions were measured at the previously inundated site. At the other site, drip irrigation provided more favourable conditions than ditch irrigation. The size of the area needed for water management (ditches, polders) strongly affected the areal GHG balances. We conclude that Sphagnum farming on highly decomposed peat is possible but requires elaborate water management.

scholarly journals Decarbonization in Shipping Industry: A Review of Research, Technology Development, and Innovation Proposals

2021 ◽  
Vol 9 (4) ◽  
pp. 415
Author(s):  
George Mallouppas ◽  
Elias Ar. Yfantis
Keyword(s):  
Financial Incentives ◽  
Alternative Fuels ◽  
Internal Combustion Engines ◽  
Review Paper ◽  
Waste Heat ◽  
Renewable Energy Sources ◽  
Grey Literature ◽  
Ghg Emissions ◽  
Shipping Industry ◽  
Research Technology

This review paper examines the possible pathways and possible technologies available that will help the shipping sector achieve the International Maritime Organization’s (IMO) deep decarbonization targets by 2050. There has been increased interest from important stakeholders regarding deep decarbonization, evidenced by market surveys conducted by Shell and Deloitte. However, deep decarbonization will require financial incentives and policies at an international and regional level given the maritime sector’s ~3% contribution to green house gas (GHG) emissions. The review paper, based on research articles and grey literature, discusses technoeconomic problems and/or benefits for technologies that will help the shipping sector achieve the IMO’s targets. The review presents a discussion on the recent literature regarding alternative fuels (nuclear, hydrogen, ammonia, methanol), renewable energy sources (biofuels, wind, solar), the maturity of technologies (fuel cells, internal combustion engines) as well as technical and operational strategies to reduce fuel consumption for new and existing ships (slow steaming, cleaning and coating, waste heat recovery, hull and propeller design). The IMO’s 2050 targets will be achieved via radical technology shift together with the aid of social pressure, financial incentives, regulatory and legislative reforms at the local, regional and international level.

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