Innovative Diffusion Driven Desalination Process

2004 ◽  
Vol 126 (3) ◽  
pp. 219-225 ◽  
Author(s):  
James F. Klausner ◽  
Yi Li ◽  
Mohamed Darwish ◽  
Renwei Mei
Keyword(s):  
Fresh Water ◽  
Direct Contact ◽  
Production Efficiency ◽  
Waste Heat ◽  
Feed Water ◽  
Water Production ◽  
Vapor Mixture ◽  
Steam Power ◽  
Low Humidity ◽  
Feed Water Temperature

An innovative diffusion driven desalination (DDD) process is presented, and its performance based on thermodynamic considerations is thoroughly explored. The desalination is driven by water vapor saturating low humidity air flowing through a diffusion tower. Liquid water is condensed out of the air/vapor mixture in a direct contact condenser. The desalination process is suitable for operation at low temperatures and may be driven by waste heat with low exergy. It is demonstrated that the DDD process can yield a fresh water production efficiency of 4.5% with thermal energy consumption of 0.56 kWh per kilogram of fresh water production based on a feed water temperature of only 50°C. An example is discussed in which the DDD process utilizes waste heat from a 100 MW steam power plant to produce 1.51 million gallons of fresh water per day.

Diffusion Driven Desalination for Simultaneous Fresh Water Production and Desulfurization

2010 ◽  
Vol 2 (3) ◽  
Author(s):  
Jameel R. Khan ◽  
James F. Klausner ◽  
Donald P. Ziegler ◽  
Srinivas S. Garimella
Keyword(s):  
Fresh Water ◽  
Fluid Transport ◽  
Transport Model ◽  
Waste Heat ◽  
Feed Water ◽  
Low Grade ◽  
Water Production ◽  
Air Stream ◽  
Mass Transport Model ◽  
Air Streams

The diffusion driven desalination (DDD) process has been previously introduced as a process for distilling water using low-grade waste heat. Here, a configuration of the DDD process is introduced for simultaneously distilling water and scrubbing sulfur dioxide (SO2) out of heated air streams, which is also known as flue gas desulfurization (FGD). This novel DDD/FGD process utilizes the low-grade waste heat carried in industrial discharge air streams. There are many applications, where the industrial air discharge also contains SO2, and in order to utilize the waste heat for the DDD process, the SO2 must be scrubbed out of the air stream. The two major components of the DDD process are the diffusion tower and the direct contact condenser. In the present work, a thermal fluid transport model for the DDD/FGD process, that includes SO2 scrubbing, is developed. It is an extension of the heat and mass transport model previously reported for the DDD process. An existing laboratory scale DDD facility was modified and tested with SO2 in the air stream and with seawater as the feed water to the diffusion tower. The experimental investigation has been completed to evaluate the fresh water production and SO2 scrubbing potential for the DDD/FGD process. The experimental results compare favorably with the model predictions. Chemical analysis on the condenser water demonstrates the capability of the DDD/FGD process to produce high quality fresh water using seawater as the input feed water to the process.

Experimental and Numerical Study of Water Distillation Performance of Small-Scale Direct Contact Membrane Distillation System

2017 ◽  
Author(s):  
Danielle Park ◽  
Elnaz Norouzi ◽  
Chanwoo Park
Keyword(s):  
Water Temperature ◽  
Direct Contact ◽  
Membrane Distillation ◽  
Small Scale ◽  
Feed Water ◽  
Water Production ◽  
Water Distillation ◽  
Direct Contact Membrane Distillation ◽  
Feed Temperature ◽  
Feed Water Temperature

A small-scale Direct Contact Membrane Distillation (DCMD) system was built to investigate its water distillation performance for varying inlet temperatures and flow rates of feed and permeate streams, and salinity. A counterflow configuration between the feed and permeate streams was used to achieve an efficient heat exchange. A two-dimensional Computational Fluid Dynamics (CFD) model was developed and validated using the experimental results. The numerical results were compared with the experiments and found to be in good agreement. From this study, the most desirable conditions for distilled water production were found to be a higher feed water temperature, lower permeate temperature, higher flow rate and less salinity. The feed water temperature had a greater impact on the water production than the permeate water temperature. The numerical simulation showed that the water mass flux was maximum at the inlet of the feed stream where the feed temperature was the highest and rapidly decreased as the feed temperature decreased.

Design and Development of a Small Multistage Flash Desalination System Using Aspen HYSYS

2019 ◽  
Author(s):  
Md. Islam ◽  
F. Banat ◽  
A. Baba ◽  
S. Abuyahya
Keyword(s):  
Solar Energy ◽  
Fresh Water ◽  
Waste Heat ◽  
Chamber Pressure ◽  
Water Production ◽  
Heating Source ◽  
Aspen Hysys ◽  
Temperature Heat ◽  
Process Reliability ◽  
Desalination Technology

Abstract Fresh water demands are increasing day by day because of growing population, industrialization, and increased living standards. Desalination technology has become a significant solution of fresh drinking water for many parts of the world. Lack of fresh water resources in dry environments has encouraged the establishment of desalination processes and developed technology to compensate for water scarcity. The MSF (multistage flash) desalination technique has received wide spread acceptance due to low temperature heat source (waste heat/inexpensive energy), simple construction high process reliability and simple maintenance. MSF typically has the highest water production cost among available desalination technologies, which can be reduced with using solar energy/co-generation. Since Abu Dhabi is in the solar belt region and is blessed with huge solar energy, MSF desalination can be powered by solar power in addition to industrial waste/fossil fuel energy, which will significantly reduce the cost as well as carbon, footprint. In this research, multistage flash desalination is modelled using ASPEN HYSYS package V8. We have designed each components of the system, mostly heating source, vacuum/flash chambers, heat exchangers and developed the whole system. Some parametric study, i.e. feed rate, top brine temperature, heat input, pressure, productivity etc. of multistage flash desalination system has been conducted in this research. Two case studies have been conducted and found a relation between feed flow rate and water production rate as well as chamber pressure with vapor formation. This design will help to build the pilot plant, do experimental test and validate the model.

A TRNSYS Dynamic Simulation Model for Photovoltaic System Powering a Reverse Osmosis Desalination Unit with Solar Energy

2010 ◽  
Vol 8 (1) ◽  
Author(s):  
Rym Chaker ◽  
Hatem Dhaouadi ◽  
Hatem Mhiri ◽  
Philippe Bournot
Keyword(s):  
Reverse Osmosis ◽  
Fresh Water ◽  
Production Capacity ◽  
Photovoltaic System ◽  
Feed Water ◽  
Water Production ◽  
Raw Water ◽  
Solar Panels ◽  
Pv System ◽  
Dynamic Simulation Model

This paper presents a Photovoltaic (PV) simulation system powering a reverse osmosis (RO) desalination unit with no energy recovery device (ERD). The simulation is carried out using commercial software, Transient System Simulation (TRNSYS®). The PV system consists on solar panels (Siemens SM55) with rated power of 55 W, connected to a storage battery via DC-DC charge controller. The load of this system is a pump, which provides the RO system with feed water. The RO unit is composed of one Filmtec spiral wound membrane. Simulation results for fresh water production showed that with a continuous feed of 1.5 m3h-1, a total capacity production of 110 m3 per year can be achieved. The effect of the main parameters in desalinated water production capacity showed that with the increase of the raw water feed flow and the PV surface, the monthly fresh water production increases. They also showed that with the increase of raw water salinity, the fresh water production decreases. This work is validated with literature experimental results.

scholarly journals Multiscale phase change, heat and mass transfer in direct contact membrane distillation

2020 ◽  
Author(s):  
◽  
Elnaz Norouzi
Keyword(s):  
Temperature Difference ◽  
Direct Contact ◽  
Waste Heat ◽  
Water Flux ◽  
Membrane Distillation ◽  
Operating Conditions ◽  
Feed Water ◽  
Direct Contact Membrane Distillation ◽  
Nacl Concentration ◽  
System Temperature

The global water shortage has become a serious threat for the world and the most promising solution for the water issue is the desalination of seawater or brackish water. In this work, direct contact membrane distillation (DCMD) as one of thermal desalination technologies was numerically and exprimentally analyzed to study its performance. A large DCMD system with multiple membrane modules in a parallel arrangement running on the waste heat from a diesel power generator was numerically analyzed using a thermo-fluid network model to study the technical feasibility of the use of the low-grade engine waste heat and simulate the distillation performance of the DCMD system. Next, a small DCMD experimental apparatus was fabricated to test for the distillation performance for various operating conditions (inlet temperatures, flow rates of feed and permeate streams and NaCl concentration) and design variables (filament spacing of a screen spacer in the flow channels and flow configuration). In the DCMD, two different regimes were observed in the water flux behavior regarding the salinity of feed water. In the first regime, from low NaCl concentration to 90% saturated NaCl concentration, there was a gradual decrease in the water flux due to the suppression of vapor pressure at the feed water which is simulated by a CFD model. In the second regime, at higher 90% saturated NaCl concentration, there was a sharp drop in the water flux due to the deposition of NaCl crystals on the membrane surface which is simulated by an analytical model using the adjusting parameter from the experiment. Finally, a nanoscale DCMD using Carbon Nanotube (CNT) membrane was numerically analyzed using non-equilibrium molecular dynamics (NEMD) simulation for different diameters and lengths of the CNT and operating conditions such as system temperature, temperature difference between the feed (hot) and permeate (cold) reservoirs, and sodium chloride (NaCl) concentration in the feed reservoir. The distillation performance of the DCMD systems is enhanced by increasing system temperature, temperature difference between feed and permeate streams, and decreasing the NaCl concentration. The permeability of the CNT membrane (1.8 x 10-5 liter/m2-s-Pa) was found two orders-of-magnitudes higher than a Polytetrafluoroethylene (PTFE) membrane (1.7 x 10-7 liter/m2-s-Pa ) used in our experimental work.

Experimental Performance Evaluation of Humidification–Dehumidification System With Direct-Contact Dehumidifier

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Saeed Dehghani ◽  
Farzaneh Mahmoudi ◽  
Abhijit Date ◽  
Aliakbar Akbarzadeh
Keyword(s):  
Production Rate ◽  
System Performance ◽  
Direct Contact ◽  
Seawater Temperature ◽  
Operating Conditions ◽  
Flow Rate Ratio ◽  
Feed Water ◽  
Water Production ◽  
Produce Water ◽  
Water Production Rate

Abstract Humidification–dehumidification (HDH) desalination with direct contact dehumidifier system is designed and fabricated. Experimental tests are performed under various operating conditions in order to explore the influence of temperatures and mass flow rates of seawater and freshwater on system performance by utilizing non-dimensional parameters. It is shown that, for any case, there is an optimum flow rate ratio of water to air, which results in a maximum water production rate. A mathematical model is utilized to evaluate the system performance and compare the outcomes with the experimental results. In addition, the effect of feed water salinity from 0–30% on the water production rate is experimentally investigated. The results showed that the maximum achieved recovery ratio of the proposed HDH system is 5% under the working condition of seawater temperature at 73 °C with 3% salinity and cold freshwater at 28 °C. Furthermore, the system was able to produce water at nearly saturated seawater feed.

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