A scale-up nanoporous membrane centrifuge for reverse osmosis desalination without fouling

TECHNOLOGY ◽  
2018 ◽  
Vol 06 (01) ◽  
pp. 36-48 ◽  
Author(s):  
Qingsong Tu ◽  
Tiange Li ◽  
Ao Deng ◽  
Kevin Zhu ◽  
Yifei Liu ◽  
...  
Keyword(s):  
Angular Velocity ◽  
Reverse Osmosis ◽  
Large Scale ◽  
Md Simulation ◽  
Scale Up ◽  
Scale Separation ◽  
Nanoporous Membrane ◽  
Micron Size ◽  
Simulation Results ◽  
Reverse Osmosis Desalination

A scale-up nanoporous membrane centrifuge is designed and modeled. It can be used for nanoscale scale separation including reverse osmosis desalination. There are micron-size pores on the wall of the centrifuge and nanoscale pores on local graphene membrane patches that cover the micron-size pores. In this work, we derived the critical angular velocity required to counter-balance osmosis force, so that the reverse-osmosis (RO) desalination process can proceed. To validate this result, we conducted a large scale (four million atoms) full atom molecular dynamics (MD) simulation to examine the critical angular velocity required for reverse osmosis at nanoscale. It is shown that the analytical results derived based on fluid mechanics and the simulation results observed in MD simulation are consistent and well matched. The main advantage of such nanomaterial based centrifuge is its intrinsic anti-fouling ability to clear [Formula: see text] and [Formula: see text] ions accumulated at the vicinity of the pores due to the Coriolis effect. Analyses have been conducted to study the relation between osmotic pressure, centrifugal pressure, and water permeability.

scholarly journals Stand-Alone Direct Current Power Network Based on Photovoltaics and Lithium-Ion Batteries for Reverse Osmosis Desalination Plant

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2772
Author(s):  
Vishwas Powar ◽  
Rajendra Singh
Keyword(s):  
Reverse Osmosis ◽  
Direct Current ◽  
Cyber Security ◽  
Large Scale ◽  
Lithium Ion ◽  
Economic Feasibility ◽  
Power Network ◽  
Variable Effect ◽  
Desalination Plant ◽  
Reverse Osmosis Desalination

Plummeting reserves and increasing demand of freshwater resources have culminated into a global water crisis. Desalination is a potential solution to mitigate the freshwater shortage. However, the process of desalination is expensive and energy-intensive. Due to the water-energy-climate nexus, there is an urgent need to provide sustainable low-cost electrical power for desalination that has the lowest impact on climate and related ecosystem challenges. For a large-scale reverse osmosis desalination plant, we have proposed the design and analysis of a photovoltaics and battery-based stand-alone direct current power network. The design methodology focusses on appropriate sizing, optimum tilt and temperature compensation techniques based on 10 years of irradiation data for the Carlsbad Desalination Plant in California, USA. A decision-tree approach is employed for ensuring hourly load-generation balance. The power flow analysis evaluates self-sufficient generation even during cloud cover contingencies. The primary goal of the proposed system is to maximize the utilization of generated photovoltaic power and battery energy storage with minimal conversions and transmission losses. The direct current based topology includes high-voltage transmission, on-the-spot local inversion, situational awareness and cyber security features. Lastly, economic feasibility of the proposed system is carried out for a plant lifetime of 30 years. The variable effect of utility-scale battery storage costs for 16–18 h of operation is studied. Our results show that the proposed design will provide low electricity costs ranging from 3.79 to 6.43 ¢/kWh depending on the debt rate. Without employing the concept of baseload electric power, photovoltaics and battery-based direct current power networks for large-scale desalination plants can achieve tremendous energy savings and cost reduction with negligible carbon footprint, thereby providing affordable water for all.

Thermal Transport in Nanocrystalline Materials

2005 ◽  
Author(s):  
Zhanrong Zhong ◽  
Xinwei Wang
Keyword(s):  
Thermal Conductivity ◽  
Specific Heat ◽  
Thermal Transport ◽  
Nanocrystalline Materials ◽  
Large Scale ◽  
Md Simulation ◽  
Fundamental Physics ◽  
Grain Sizes ◽  
Simulation Results ◽  
Thermal Phenomena

In this work, thermal transport in nanocrystalline materials is studied using large-scale equilibrium molecular dynamics (MD) simulation. Nanocrystalline materials with different grain sizes are studied to explore how and to what extent the size of nanograins affects the thermal conductivity and specific heat. Substantial thermal conductivity reduction is observed and the reduction is stronger for nanocrystalline materials with smaller grains. On the other hand, the specific heat of nanocrystalline materials shows little change with the grain size. The simulation results are compared with the thermal transport in individual nanograins based on MD simulation. Further discussions are provided to explain the fundamental physics behind the observed thermal phenomena in this work.

Virtual Prototype Modeling and Dynamics Analysis of a Large-Scale Wind Turbine’s Gearbox

2011 ◽  
Vol 314-316 ◽  
pp. 1043-1047
Author(s):  
Guo Yu Hu ◽  
Wen Lei Sun
Keyword(s):  
Optimal Design ◽  
Angular Velocity ◽  
Wind Turbine ◽  
Large Scale ◽  
Virtual Prototype ◽  
Design Parameters ◽  
Prototype Model ◽  
Flexible Body ◽  
Dynamics Analysis ◽  
Simulation Results

With the gearbox of a large-scale wind turbine as a study object, the virtual prototype model of gearbox is created based on UG and ADAMS softwares according to its design parameters such as structure and size. By rigid and flexible dynamics analysis for gearbox, the angular velocity and acceleration curves of the in-out shaft are obtained. Gear meshing forces and flexible body stress cloud using ADAMS are also obtained. It is verified that these results are coincided with the theoretical value through analysis and the simulation results of ADAMS are valid. The simulation results show that the design level of wind turbine gearboxes can be improved using the virtual prototype technology and lay a good foundation for further optimal design.

Reverse osmosis desalination of QNI Yabulu Nickel Refinery wastewater for reuse

2003 ◽  
Vol 3 (3) ◽  
pp. 125-131
Author(s):  
J. Milsom ◽  
N. Palmer ◽  
M. Smallwood
Keyword(s):  
Reverse Osmosis ◽  
Large Scale ◽  
Waste Stream ◽  
Water Recycling ◽  
Refinery Wastewater ◽  
Electro Magnetic ◽  
Desalination Plants ◽  
Tailings Ponds ◽  
Reverse Osmosis Desalination

Queensland Nickel Pty Limited commissioned a water recycling facility incorporating micro-filtration and reverse osmosis to treat wastewater from its Yabulu Nickel Refinery in North Queensland. Used process waters are brackish and unsuitable for reuse in the refinery. They have traditionally been stored in tailings ponds for evaporation, or discharged to sea under environmental authority. The development has demonstrated the potential for large-scale industrial desalination plants by recycling wastewater for reuse in the plant. By recycling this 12 ML/day waste stream, the refinery's new water input has been reduced by 40%. The utilisation of electro-magnetic anti-scaling technology in the reverse osmosis system is also discussed. No anti-scalant chemicals are used in the process.

scholarly journals Thermodynamic Limitations and Exergy Analysis of Brackish Water Reverse Osmosis Desalination Process

Membranes ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 11
Author(s):  
Alanood A. Alsarayreh ◽  
Mudhar A. Al-Obaidi ◽  
Alejandro Ruiz-García ◽  
Raj Patel ◽  
Iqbal M. Mujtaba
Keyword(s):  
Reverse Osmosis ◽  
Brackish Water ◽  
Exergy Analysis ◽  
Exergy Destruction ◽  
First Pass ◽  
Simulation Results ◽  
Membrane Technologies ◽  
Physical And Chemical ◽  
Exergy Losses ◽  
Reverse Osmosis Desalination

The reverse osmosis (RO) process is one of the most popular membrane technologies for the generation of freshwater from seawater and brackish water resources. An industrial scale RO desalination consumes a considerable amount of energy due to the exergy destruction in several units of the process. To mitigate these limitations, several colleagues focused on delivering feasible options to resolve these issues. Most importantly, the intention was to specify the most units responsible for dissipating energy. However, in the literature, no research has been done on the analysis of exergy losses and thermodynamic limitations of the RO system of the Arab Potash Company (APC). Specifically, the RO system of the APC is designed as a medium-sized, multistage, multi pass spiral wound brackish water RO desalination plant with a capacity of 1200 m3/day. Therefore, this paper intends to fill this gap and critically investigate the distribution of exergy destruction by incorporating both physical and chemical exergies of several units and compartments of the RO system. To carry out this study, a sub-model of exergy analysis was collected from the open literature and embedded into the original RO model developed by the authors of this study. The simulation results explored the most sections that cause the highest energy destruction. Specifically, it is confirmed that the major exergy destruction happens in the product stream with 95.8% of the total exergy input. However, the lowest exergy destruction happens in the mixing location of permeate of the first pass of RO desalination system with 62.28% of the total exergy input.

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