Solar desalination system of combined solar still and humidification-dehumidification unit

Science.gov (United States)

Ghazy, Ahmed; Fath, Hassan E. S.

2016-11-01

Solar stills, as a simple technology, have many advantages such as simple design; unsophisticated fabrication; low capital and operation costs and easily maintained. However, their low daily production has put constraints on their usage. A radical improvement in the performance of solar stills can be achieved by the partial recovery of the energy losses from the glass cover of the still. This paper simulates a direct solar distillation system of combined solar still with an air heating humidification-dehumidification (HDH) sub-system. The main objective of the Still-HDH system is to improve the productivity and thermal efficiency of the conventional solar still by partially recovering the still energy losses to the ambient for additional water production. Various procedures have been employed to improve the thermal performance of the integrated system by recovering heat losses from one component in another component of the system. Simulations have been carried out for the performance of the Still-HDH system under different weather conditions. A comparison has been held between the Still-HDH system and a conventional solar still of the same size and under the same operating conditions.

Study on bubble column humidification and dehumidification system for coal mine wastewater treatment.

Science.gov (United States)

Gao, Penghui; Zhang, Meng; Du, Yuji; Cheng, Bo; Zhang, Donghai

2018-04-01

Water is important resource for human survival and development. Coal mine wastewater (CMW) is a byproduct of the process of coal mining, which is about 7.0 × 10 10 m 3 in China in 2016. Considering coal mine wastewater includes different ingredients, a new bubble column humidification and dehumidification system is proposed for CMW treatment. The system is mainly composed of a bubble column humidification and dehumidification unit, solar collector, fan and water tank, in which air is used as a circulating medium. The system can avoid water treatment component blocking for reverse osmosis (RO) and multi effect distillation (MED) dealing with CMW, and produce water greenly. By analysis of heat and mass transfer, the effects of solar radiation, air bubble velocity and mine water temperature on water treatment production characteristics are studied. Compared with other methods, thermal energy consumption (TEC) of bubble column humidification and dehumidification (BCHD) is moderate, which is about 700 kJ/kg (powered by solar energy). The results would provide a new method for CMW treatment and insights into the efficient coal wastewater treatment, besides, it helps to identify the parameters for the technology development in mine water treatment.

Theoretical simulation of small scale psychometric solar water desalination system in semi-arid region

International Nuclear Information System (INIS)

Shatat, Mahmoud; Omer, Siddig; Gillott, Mark; Riffat, Saffa

2013-01-01

Many countries around the world suffer from water scarcity. This is especially true in remote and semi-arid regions in the Middle East and North Africa (MENA) where per capita water supplies decline as populations increase. This paper presents the results of a theoretical simulation of an affordable small scale solar water desalination plant using the psychometric humidification and dehumidification process coupled with an evacuated tube solar collector with an area of about 2 m 2 . A mathematical model was developed to describe the system's operation. Then a computer program using Simulink Matlab software was developed to provide the governing equations for the theoretical calculations of the humidification and dehumidification processes. The experimental and theoretical values for the total daily distillate output were found to be closely correlated. After the experimental calibration of the mathematical model, a model simulating solar radiation under the climatic conditions in the Middle East region proved that the performance of the system could be improved to produce a considerably higher amount of fresh water, namely up to 17.5 kg/m 2 day. This work suggests that utilizing the concept of humidification and dehumidification, a compact water desalination unit coupled with solar collectors would significantly increase the potable water supply in remote area. It could be a unique solution of water shortages in such areas. -- Highlights: • An affordable small scale desalination system is proposed. • A mathematical model of the desalination system is developed and programmed using Matlab Simulink. • The model describes the psychometric process based on humidification and dehumidification. • The model is used in optimal selection of elements and operating conditions for solar desalination system. • The use of solar water desalination contributes significantly to reducing global warming

The effects of de-humidification and O{sub 2} direct injection in oxy-PC combustion

Energy Technology Data Exchange (ETDEWEB)

Choi, C.G.; Na, I.H.; Lee, J.W.; Chae, T.Y.; Yang, W. [Korea Insitute of Industrial Technology, Seoul (Korea, Republic of). Energy System R and D Dept.

2013-07-01

This study is aimed to derive effects of de-humidification and O{sub 2} direct injection in oxy-PC combustion system. Temperature distribution and flue gas composition were observed for various air and oxy-fuel conditions such as effect of various O{sub 2} concentration of total oxidant, O{sub 2} concentration of primary stream and O{sub 2} direct injection through 0-D heat and mass balance calculation and experiments in the oxy-PC combustion system of 0.3 MW scale in KITECH (Korea Institute of Industrial Technology). Flame attachment characteristic related to O{sub 2} direct injection was also observed experimentally. We found that FEGT (furnace exit gas temperature) of 100% de-humidification to oxidizer is lower than humidification condition; difference between two conditions is lower than 20 C in all cases. The efficiency changing of combustion was negligible in O{sub 2} direct injection. But O{sub 2} direct injection should be carefully designed to produce a stable flame.

Performance investigation of a novel water–power cogeneration plant (WPCP) based on humidification dehumidification (HDH) method

International Nuclear Information System (INIS)

He, W.F.; Han, D.; Xu, L.N.; Yue, C.; Pu, W.H.

2016-01-01

Highlights: • A novel water–power cogeneration plant (WPCP) is proposed. • Energy analysis of the proposed WPCP is achieved. • Comparison of the WPCP performance at different pressures is fulfilled. • Performance correlation between the HDH desalination and ORC power subsystems is revealed. - Abstract: Humidification dehumidification (HDH) technology was well applied to produce freshwater in the desalination system. However, besides the demand of freshwater, power is also required simultaneously in most situations. In the paper, a novel water–power cogeneration plant (WPCP) based on the HDH desalination system coupled with the organic Rankine cycle (ORC) is proposed. Energy analysis for the proposed combined system at different appointed operation parameters is achieved, and the corresponding performance correlation between the HDH desalination and ORC power system are revealed. It is verified that the production of freshwater and electricity can be gained synchronously in the suggested novel platform, and the performance of the whole system is really sensitive to the operation parameters of the HDH desalination system. It is found that after the regulation of the operation pressure, p, and the seawater temperature at the outlet of the seawater heater, T sw,2 , for the HDH desalination from p = 0.1 MPa, T sw,2 = 353.15 K to p = 0.3 MPa, T sw,2 = 383.15 K, a maximum elevation, 25.46 kg h −1 for the freshwater production, 4.17 kW for the electricity and 2% for the extended gained output ratio (EGOR) is obtained. Furthermore, owing to the asynchronism between the specific production and the final energy utilization efficiency, the balance should be optimized among the demand of the freshwater and power and the efficiency of the novel WPCP.

New solar desalination system using humidification/ dehumidification process

Energy Technology Data Exchange (ETDEWEB)

Abdel Dayem, Adel M. [Mechanical Engineering Department, College of Engineering and Islamic Architecture, Umm Al-Qura University, 5555 Makah (Saudi Arabia)

2013-07-01

An innovative solar desalination system is successfully designed, manufactured and experimentally tested at Makkah, 21.4 °N. The system consists of 1.15 m2 flat-plate collector as a heat source and a desalination unit. The unit is about 400 liter vertical cylindrical insulated tank. It includes storage, evaporator and condenser of hot salt-water that is fed from the collector. The heated water in the collector is raised naturally to the unit bottom at which it is used as storage. A high pressure pump is used to inject the water vertically up through 1-mm three nozzles inside the unit. The hot salt-water is atomized inside the unit where the produced vapor is condensed on the inner surfaces of the unit outer walls to outside. The system was experimentally tested under different weather conditions. It is obtained that the system can produce about 9 liter a day per quadratic meter of collector surface area. By that it can produce about 1.6 liters per kWh of solar energy. Moreover the water temperature has a great effect on the system performance although the scaling possibility is becoming significant. By that way the cost of a liter water production is relatively high and is obtained as 0.5 US$.

Humidification Dehumidification Spray Column Direct Contact Condenser Part I: Countercurrent Flow

International Nuclear Information System (INIS)

Shouman, L.; Karameldin, A.; Fadel, D.

2015-01-01

Humidification-dehumidification (HDH) is a low grade energy desalination technology. The waste heat from power plant (such NPP) can be used as heat source to preheat water (in evaporator) and air (in condenser) . Hot humid air and cooled spray water in counter current flow with direct contact is theoretically analyzing in the present work. Direct contact spray condenser is studied to provide the effect of various parameters on its performance. A computer programme describing the theoretical model is designed to solve a one-dimensional differential equations by using Rung–Kutta method. The programme predicts the droplet radius, velocity and temperature, besides, the humidity and temperature of air. The results show that, the length of column has great effect on the performance of spray condenser. At column height of 0.762, 2, 5, 10, and 20 m the humidity of the output air decreases by 50%, 72%, 89%, 97%, and 99% respectively. The condensate increases about 35% when the length increase from 5 to 10 m at ΔT = 25°C while increase only 18% at ΔT = 30°C. Also, it is found that, at ΔT = 25°C the condensate decrease from H = 10 to 5 m about 31% and increases from 10 to 20 m about 32%. While these results for ΔT = 25°C are 32% from H = 10 to 5 m and 36% from 10 to 20 m.The increase of both water and air mass fluxes increases the condensate mass flow rate. (author)

Experimental investigation of a portable desalination unit configured by a thermoelectric cooler

International Nuclear Information System (INIS)

Yıldırım, Cihan; Soylu, Sezgi Koçak; Atmaca, İbrahim; Solmuş, İsmail

2014-01-01

Highlights: • Portable humidification–dehumidification desalination system configured by a thermoelectric cooler is experimentally studied. • Effect of feed water mass flow rate and air flow velocity on COP value of TEC and system productivity are investigated. • Maximum daily yield of system and COP value of TEC unit were recorded as 143.6 g and 0.78, respectively. - Abstract: Possible use of a novel portable desalination system was investigated experimentally. The system is based on humidification–dehumidification principle and thermoelectric cooling technique. A thermoelectric cooler was integrated into the system to enhance the process of both humidification and dehumidification. A prototype was fabricated and its performance was tested for various working conditions of the prototype to observe complex relation between psychrometric and thermoelectric phenomena. The effect of feed water mass flow rate and air flow velocity on the COP value of the thermoelectric cooler and clean water production of the system were examined. The maximum daily yield of the system and the COP value of the thermoelectric cooler unit were recorded as 143.6 g and 0.78, respectively

A parametric study on a humidification–dehumidification (HDH) desalination unit powered by solar air and water heaters

International Nuclear Information System (INIS)

Yıldırım, Cihan; Solmuş, İsmail

2014-01-01

Highlights: • A time dependent humidification–dehumidification desalination process is investigated. • Fourth-order Runge–Kutta method is used to simulate the problem. • Daily and annual performance are examined. • Various operational parameters are investigated. - Abstract: The performance of a solar powered humidification–dehumidification desalination system is theoretically investigated for various operating and design parameters of the system under climatological conditions of Antalya, Turkey. The primary components of the system are a flat plate solar water heater, a flat plate double pass solar air heater, a humidifier, a dehumidifier and a storage tank. The mathematical model of the system is developed and governing conservation equations are numerically solved by using the Fourth order Runge–Kutta method. Daily and annual yields are calculated for different configurations of the system such as only water heating, only air heating and water–air heating

Forward Osmosis in India: Status and Comparison with Other Desalination Technologies.

Science.gov (United States)

Mehta, Dhruv; Gupta, Lovleen; Dhingra, Rijul

2014-01-01

With an increase in demand of freshwater and depleting water sources, it is imperative to switch to seawater as a regular source of water supply. However, due to the high total dissolved solid content, it has to be desalinated to make it drinkable. While desalination technologies have been used for many years, mass deployment of such technologies poses a number of challenges like high energy requirements as well as high negative environmental impact through side products and CO2 emissions. The purpose of this paper is to present a sustainable technology for desalination. Forward osmosis, an emerging technology, is compared with the other commonly used technologies worldwide, namely, multieffect distillation, multistage flash distillation, and reverse osmosis as well as other emerging technologies like vapour compression, solar humidification dehumidification, nanofiltration, and freezing desalination. As energy consumption and associated greenhouse gas emissions are one of the major concerns of desalination, this paper concludes that forward osmosis is an emerging sustainable technology for seawater desalination. This paper then presents the challenges involved in the application of forward osmosis in India and presents a plant setup. In the end, the cost comparison of a forward osmosis and reverse osmosis plant has been done and it was concluded that forward osmosis is economically better as well.

Forward Osmosis in India: Status and Comparison with Other Desalination Technologies

Science.gov (United States)

2014-01-01

With an increase in demand of freshwater and depleting water sources, it is imperative to switch to seawater as a regular source of water supply. However, due to the high total dissolved solid content, it has to be desalinated to make it drinkable. While desalination technologies have been used for many years, mass deployment of such technologies poses a number of challenges like high energy requirements as well as high negative environmental impact through side products and CO2 emissions. The purpose of this paper is to present a sustainable technology for desalination. Forward osmosis, an emerging technology, is compared with the other commonly used technologies worldwide, namely, multieffect distillation, multistage flash distillation, and reverse osmosis as well as other emerging technologies like vapour compression, solar humidification dehumidification, nanofiltration, and freezing desalination. As energy consumption and associated greenhouse gas emissions are one of the major concerns of desalination, this paper concludes that forward osmosis is an emerging sustainable technology for seawater desalination. This paper then presents the challenges involved in the application of forward osmosis in India and presents a plant setup. In the end, the cost comparison of a forward osmosis and reverse osmosis plant has been done and it was concluded that forward osmosis is economically better as well. PMID:27350984

Humidification-Dehumidification (HDH) Spray Column Direct Contact Condenser Part I: Countercurrent Flow

International Nuclear Information System (INIS)

Karameldin, A.; Shouman, L.; Fadel, D.

2016-01-01

Humidification-De humidification (HDH) is a low grade energy desalination technology. Hot humid air and cooling spray water in counter current flow with direct contact is theoretically analyzed in the present work. Direct contact spray condenser is studied to obtain the effect of various parameters on its performance. A computer program describing the theoretical model is designed to solve one-dimensional differential equations by using Rung-Kutta method. The results show that the column length has a great effect on the performance of the spray condenser. At a column height of 2, 5,10, and 20 m the humidity of the outlet air decreases by 72, 89, 97, and 99% respectively. The humid air temperature has a great influence on the productivity; me an while the temperature difference between the humid air and sprayed water has less effect. A case study of a contiguous co-generation electricity and water in Nuclear Power Plants (NPP) shows that the optimal productivity by HDH is feasible and can reach more than 15 m"3 /day.m"2, enabling a total productivity that varied from 120,000 to 300,000 m"3 /day. The design curves describing the process are obtained together in addition to a formula for the optimal productivity in terms of humid air and sprayed water fluxes at different humid air temperatures is derived

Entropy Generation Analysis of Desalination Technologies

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John H. Lienhard V

2011-09-01

Full Text Available Increasing global demand for fresh water is driving the development and implementation of a wide variety of seawater desalination technologies. Entropy generation analysis, and specifically, Second Law efficiency, is an important tool for illustrating the influence of irreversibilities within a system on the required energy input. When defining Second Law efficiency, the useful exergy output of the system must be properly defined. For desalination systems, this is the minimum least work of separation required to extract a unit of water from a feed stream of a given salinity. In order to evaluate the Second Law efficiency, entropy generation mechanisms present in a wide range of desalination processes are analyzed. In particular, entropy generated in the run down to equilibrium of discharge streams must be considered. Physical models are applied to estimate the magnitude of entropy generation by component and individual processes. These formulations are applied to calculate the total entropy generation in several desalination systems including multiple effect distillation, multistage flash, membrane distillation, mechanical vapor compression, reverse osmosis, and humidification-dehumidification. Within each technology, the relative importance of each source of entropy generation is discussed in order to determine which should be the target of entropy generation minimization. As given here, the correct application of Second Law efficiency shows which systems operate closest to the reversible limit and helps to indicate which systems have the greatest potential for improvement.

Performance analysis of a novel heat pump type air conditioner coupled with a liquid dehumidification/humidification cycle

International Nuclear Information System (INIS)

Cai, Dehua; Qiu, Chengbo; Zhang, Jiazheng; Liu, Yue; Liang, Xiao; He, Guogeng

2017-01-01

decreases by about 22.64% when compared with conventional air conditioner. Theoretical results also indicate that the coefficient of performance (COP) of the novel system has a potential improvement of about 35.3%. Based on the theoretical results, experimental analyses of this novel cycle under summer and winter working conditions are carried out. In addition, comparison of the humidification and dehumidification ability as well as COP of the present novel system and the traditional one are carried out. Researching results of the present study provide important reference for investigator of this field.

Design and development of an air humidifier using finite difference method for a solar desalination plant

Science.gov (United States)

Chiranjeevi, C.; Srinivas, T.

2017-11-01

Humidifier is an important component in air humidification-dehumidification desalination plant for fresh water production. Liquid to air flow rate ratio is optimization is reported for an industrial cooling towers but for an air humidifier it is not addressed. The current work is focused on the design and analysis of an air humidifier for solar desalination plant to maximize the yield with better humidification, using finite difference method (FDM). The outlet conditions of air from the humidifier are theoretically predicted by FDM with the given inlet conditions, which will be further used in the design calculation of the humidifier. Hot water to air flow rate ratio and inlet hot water temperature are identified as key operating parameters to evaluate the humidifier performance. The maximum and optimal values of mass flow rate ratio of water to air are found to be 2.15 and 1.5 respectively using packing function and Merkel Integral. The height of humidifier is constrained to 1.5 m and the diameter of the humidifier is found as 0.28m. The performance of humidifier and outlet conditions of air are simulated using FDM and compared with experimental results. The obtained results are within an agreeable range of deviation.

Entropy Generation of Desalination Powered by Variable Temperature Waste Heat

Directory of Open Access Journals (Sweden)

David M. Warsinger

2015-10-01

Full Text Available Powering desalination by waste heat is often proposed to mitigate energy consumption and environmental impact; however, thorough technology comparisons are lacking in the literature. This work numerically models the efficiency of six representative desalination technologies powered by waste heat at 50, 70, 90, and 120 °C, where applicable. Entropy generation and Second Law efficiency analysis are applied for the systems and their components. The technologies considered are thermal desalination by multistage flash (MSF, multiple effect distillation (MED, multistage vacuum membrane distillation (MSVMD, humidification-dehumidification (HDH, and organic Rankine cycles (ORCs paired with mechanical technologies of reverse osmosis (RO and mechanical vapor compression (MVC. The most efficient technology was RO, followed by MED. Performances among MSF, MSVMD, and MVC were similar but the relative performance varied with waste heat temperature or system size. Entropy generation in thermal technologies increases at lower waste heat temperatures largely in the feed or brine portions of the various heat exchangers used. This occurs largely because lower temperatures reduce recovery, increasing the relative flow rates of feed and brine. However, HDH (without extractions had the reverse trend, only being competitive at lower temperatures. For the mechanical technologies, the energy efficiency only varies with temperature because of the significant losses from the ORC.

Desalination Processes Evaluation at Common Platform: A Universal Performance Ratio (UPR) Method

KAUST Repository

Wakil Shahzad, Muhammad

2018-01-31

The inevitable escalation in economic development have serious implications on energy and environment nexus. The International Energy Outlook 2016 (IEO2016) predicted that the Non Organization for Economic Cooperation and Development (non-OECD) countries will lead with 71% rise in energy demand in contrast with only 18% in developed countries from 2012-2040. In Gulf Cooperation Council (GCC) countries, about 40% of primary energy is consumed for cogeneration based power and desalination plants. The cogeneration based plants are struggling with unfair primary fuel cost apportionment to electricity and desalination. Also, the desalination processes performance evaluated based on derived energy, providing misleading selection of processes. There is a need of (i) appropriate primary fuel cost appointment method for multi-purposed plants and (ii) desalination processes performance evaluation method based on primary energy. As a solution, we proposed exergetic analysis for primary fuel percentage apportionment to all components in the cycle according to the quality of working fluid utilized. The proposed method showed that the gas turbine was under charged by 40%, steam turbine was overcharged by 71% and desalination was overcharged by 350% by conventional energetic apportionment methods. We also proposed a new and most suitable desalination processes performance evaluation method based on primary energy, called universal performance ratio (UPR). Since UPR is based on primary energy, it can be used to evaluate any kind of desalination processes, thermally driven, pressure driven & humidification-dehumidification etc. on common platform. We showed that all desalination processes are operating only at 10-13% of thermodynamic limit (TL) of UPR. For future sustainability, desalination must achieve 25-30% of TL and it is only possible either by hybridization of different processes or by innovative membrane materials.

Development of an innovative polygeneration process in hybrid solar-biomass system for combined power, cooling and desalination

International Nuclear Information System (INIS)

Sahoo, U.; Kumar, R.; Pant, P.C.; Chaudhary, R.

2017-01-01

Highlights: • Heat utilization from solar and biomass resources are considered for hybridization. • Modeling of polygeneration process in hybrid solar-biomass power plant is considered. • Thermodynamic evaluation are performed to identify the effect of various parameters. • Primary Energy Saving of polygeneration process is determined. - Abstract: In the polygeneration process simultaneous production of power, vapor absorption refrigeration (VAR) cooling and multi-effect humidification and dehumidification (MEHD) desalination system from different heat sources in hybrid solar-biomass (HSB) system with higher energy efficiency take place. It is one of the solutions to fulfill energy requirements from renewable sources and also helps in the reduction of carbon dioxide emissions. The VAR cooling system operates using the extracted heat taken from turbine and condenser heat of the VAR cooling system is used in desalination system for production of drinking water as per demand requirement. Though the production of electricity decreases due to extraction of heat from turbine for VAR cooling and desalination, the complete system meets the energy requirements & increases the primary energy savings (PES). The thermodynamic evaluation and optimization of HSB system in polygeneration process for combined power, cooling and desalination is investigated to identify the effects of various operating parameters. Primary energy savings (PES) of polygeneration process in HSB system is achieved to 50.5%. The energy output is increased to 78.12% from this system as compared to simple power plant.

Modeling and PSO optimization of Humidifier-Dehumidifier desalination

Directory of Open Access Journals (Sweden)

Mohammad Hossein Ahmadi

2018-02-01

Full Text Available The aim of this study is modeling a solar-air heater humidification-dehumidification unit with applying particle swarm optimization to find out  the maximum gained output ratio with respect to the mass flow rate of water and air entering humidifier, mass flow rate of cooling water entering dehumidifier, width and length of solar air heater and terminal temperature difference (TTD of dehumidifier representing temperature difference of inlet cooling water and saturated air to dehumidifier as its decision variable. A sensitivity analysis, furthermore, is performed to distinguish the effect of operating parameters including mass flow rate and streams’ temperature. The results showed that the optimum productivity decreases by decreasing the ratio of mass flow rate of water entering humidifier to air ones. Article History: Received: July 12th 2017; Revised: December 15th 2017; Accepted: 2nd February 2018; Available online How to Cite This Article: Afshar, M.A., Naseri, A., Bidi, M., Ahmadi, M.H. and Hadiyanto, H. (2018 Modeling and PSO Optimization of Humidifier-Dehumidifier Desalination. International Journal of Renewable Energy Development, 7(1,59-64. https://doi.org/10.14710/ijred.7.1.59-64

Effect of ventilated structure on dehumidification. ; Experimental result in winter. Tsuki koho no haishitsu koka ni kansuru kenkyu. ; Toki jikken kekka

Energy Technology Data Exchange (ETDEWEB)

Sugai, T; Ozaki, A [Fukuoka University, Fukuoka (Japan). Faculty of Engineering; Katayama, T; Hayashi, T; Shiotsuki, Y [Kyushu University, Fukuoka (Japan)

1912-09-01

Temperature and humidity characteristics and condensation within walls under heating and humidification were studied experimentally in winter using two test houses of conventional and ventilated structures. The absolute humidity in conventional one fluctuated depending on temperature gradient, water flux due to humidification and water adsorption onto glass wool, and accumulated water increased with humidification. That in ventilated one was also affected by dehumidification through ventilation layers. Under heating and humidification, the absolute humidity increased depending on temperature rise and water flux within walls. In conventional one, condensation was frequently observed on felt in walls and others because of accumulated humidity, while in ventilated one, humidity was kept lower within walls even under heating, because humidity in walls was discharged through ventilation layers. Condensation was also scarcely observed on waterproof moisture-permeable sheets in walls and others. 3 refs ., 39 figs 1., tab.

Performance evaluation of a solar energy assisted hybrid desiccant air conditioner integrated with HDH desalination system

International Nuclear Information System (INIS)

Kabeel, A.E.; Abdelgaied, Mohamed; Zakaria, Yehya

2017-01-01

Highlights: • The performance of a solar hybrid air conditioner integrated with HDH desalination system is numerically investigated. • For increase the regeneration air from 70 to 130 m 3 /h, the distillate water productivity increases from 2.988 to 4.78 L/h. • For increase the regeneration air from 70 to 130 m 3 /h, COP overall daily decreases from 4.66 to 3.386. • For increases the regeneration air temperature from 75 to 95 °C, the distillate water increases from 3.1752 to 5.011 L/h. • For increases the regeneration air temperature from 75 to 95 °C, COP overall daily decreases from 4.392 to 3.636. - Abstract: In this study, the performances of a solar energy assisted hybrid desiccant air conditioning system integrated with humidification–dehumidification (HDH) desalination system are numerically investigated. The aim of this study is to benefit from the temperature rise of the regeneration air outside of the desiccant conditioning system as well as the water vapor content in this regeneration air by feeding it to the humidification-dehumidification water desalination unit to produce distillate water. The distillate water productivity, human thermal comfort issues, and energy saving represent the main objective of the present numerical study. The simulated results developed for subsystems are validated with the published experimental results. The effects of regeneration air temperature and flow rate on supply cooled air temperature, distillate water productivity, the cooling coefficient of performance and overall daily coefficient of performance of the proposed system are investigated. The results show that (i) the distillate water productivity increases from 3.175 to 5.011 L/h and overall daily coefficient of performance decreases from 4.392 to 3.636 with increasing the regeneration air temperature from 75 to 95 as (ii) the increase in the regeneration air flow rate from 70 to 130 m 3 /h, increases the distillate water productivity from 2.988 to 4

Procedures of water desalination with solar energy and f-chart method

Directory of Open Access Journals (Sweden)

Petrović Andrija A.

2015-01-01

Full Text Available Due to rapid population growth, and climate change caused by environmental pollution needs for drinking water are increasing while amount of freshwater are decreasing. However possible solution for freshwater scarcity can be found in water desalination procedures. In this article three representative water desalination solar powered plants are described. Except explanation of processes it is also mentioned basic advantages and disadvantages of humidification, reverse osmosis and desalination evaporation by using solar energy. Simulation of the solar desalination system is analyzed with f-chart method monthly, located on located 42 degrees north latitude.

A bubble column evaporator with basic flat-plate condenser for brackish and seawater desalination.

Science.gov (United States)

Schmack, Mario; Ho, Goen; Anda, Martin

2016-01-01

This paper describes the development and experimental evaluation of a novel bubble column-based humidification-dehumidification system, for small-scale desalination of saline groundwater or seawater in remote regions. A bubble evaporator prototype was built and matched with a simple flat-plate type condenser for concept assessment. Consistent bubble evaporation rates of between 80 and 88 ml per hour were demonstrated. Particular focus was on the performance of the simple condenser prototype, manufactured from rectangular polyvinylchlorid plastic pipe and copper sheet, a material with a high thermal conductivity that quickly allows for conduction of the heat energy. Under laboratory conditions, a long narrow condenser model of 1500 mm length and 100 mm width achieved condensate recovery rates of around 73%, without the need for external cooling. The condenser prototype was assessed under a range of different physical conditions, that is, external water cooling, partial insulation and aspects of air circulation, via implementing an internal honeycomb screen structure. Estimated by extrapolation, an up-scaled bubble desalination system with a 1 m2 condenser may produce around 19 l of distilled water per day. Sodium chloride salt removal was found to be highly effective with condensate salt concentrations between 70 and 135 µS. Based on findings and with the intent to reduce material cost of the system, a shorter condenser length of 750 mm for the non-cooled (passive) condenser and of 500 mm for the water-cooled condenser was considered to be equally efficient as the experimentally evaluated prototype of 1500 mm length.

Developing a Standard Method of Test for Packaged, Solid-Desiccant Based Dehumidification Systems

International Nuclear Information System (INIS)

Sand, J.R.

2001-01-01

A draft Method of Test (MOT) has been proposed for packaged, air-to-air, desiccant-based dehumidifier systems that incorporate a thermally-regenerated desiccant material for dehumidification. This MOT is intended to function as the ''system'' testing and rating compliment to the desiccant ''component'' (desiccant wheels and/or cassettes) MOT (ASHRAE 1998) and rating standard (ARI 1998) already adopted by industry. This draft standard applies to ''packaged systems'' that: Use desiccants for dehumidification of conditioned air for buildings; Use heated air for regeneration of the desiccant material; Include fans for moving process and regeneration air; May include other system components for filtering, pre-cooling, post-cooling, or heating conditioned air; and May include other components for humidification of conditioned air. The proposed draft applies to four different system operating modes depending on whether outdoor or indoor air is used for process air and regeneration air streams . Only the ''ventilation'' mode which uses outdoor air for both process and regeneration inlets is evaluated in this paper. Performance of the dehumidification system is presented in terms that would be most familiar and useful to designers of building HVAC systems to facilitate integration of desiccant equipment with more conventional hardware. Parametric performance results from a modified, commercial desiccant dehumidifier undergoing laboratory testing were used as data input to evaluate the draft standard. Performance results calculated from this experimental input, results from an error-checking/heat-balance verification test built into the standard, and estimated comparisons between desiccant and similarly performing conventional dehumidification equipment are calculated and presented. Some variations in test procedures are suggested to aid in analytical assessment of individual component performance

A Liquid Desiccant Cycle for Dehumidification and Fresh Water Supply in Controlled Environment Agriculture

KAUST Repository

Lefers, Ryan

2017-12-01

Controlled environment agriculture allows the production of fresh food indoors from global locations and contexts where it would not otherwise be possible. Growers in extreme climates and urban areas produce food locally indoors, saving thousands of food import miles and capitalizing upon the demand for fresh, tasty, and nutritious food. However, the growing of food, both indoors and outdoors, consumes huge quantities of water - as much as 70-80% of global fresh water supplies. The utilization of liquid desiccants in a closed indoor agriculture cycle provides the possibility of capturing plant-transpired water vapor. The regeneration/desalination of these liquid desiccants offers the potential to recover fresh water for irrigation and also to re-concentrate the desiccants for continued dehumidification. Through the utilization of solar thermal energy, the process can be completed with a very small to zero grid-energy footprint. The primary research in this dissertation focused on two areas: the dehumidification of indoor environments utilizing liquid desiccants inside membrane contactors and the regeneration of these desiccants using membrane distillation. Triple-bore PVDF hollow fiber membranes yielded dehumidification permeance rates around 0.25-0.31 g m-2 h-1 Pa-1 in lab-scale trials. A vacuum membrane distillation unit utilizing PVDF fibers yielded a flux of 2.8-7.0 kg m-2 hr-1. When the membrane contactor dehumidification system was applied in a bench scale controlled environment agriculture setup, the relative humidity levels responded dynamically to both plant transpiration and dehumidification rates, reaching dynamic equilibrium levels during day and night cycles. In addition, recovered fresh water from distillation was successfully applied for irrigation of crops and concentrated desiccants were successfully reused for dehumidification. If applied in practice, the liquid desiccant system for controlled environment agriculture offers the potential to reduce

Humidification dehumidification desalination system using parabolic trough solar air collector

International Nuclear Information System (INIS)

Al-Sulaiman, Fahad A.; Zubair, M. Ifras; Atif, Maimoon; Gandhidasan, Palanichamy; Al-Dini, Salem A.; Antar, Mohamed A.

2015-01-01

This paper deals with a detailed thermodynamic analysis to assess the performance of an HDH system with an integrated parabolic trough solar collector (PTSC). The HDH system considered is an open air, open water, air heated system that uses a PTSC as an air heater. Two different configurations were considered of the HDH system. In the first configuration, the solar air heater was placed before the humidifier whereas in the second configuration the solar air heater was placed between the humidifier and the dehumidifier. The current study revealed that PTSCs are well suited for air heated HDH systems for high radiation location, such as Dhahran, Saudi Arabia. The comparison between the two HDH configurations demonstrates that the gained output ratio (GOR) of the first configuration is, on average, about 1.5 whereas for the second configuration the GOR increases up to an average value of 4.7. The study demonstrates that the HDH configuration with the air heater placed between the humidifier and the dehumidifier has a better performance and a higher productivity. - Highlights: • Thermodynamic analysis of an HDH system driven by a parabolic trough solar collector was conducted. • The first configuration reveals a GOR of 1.5 while the second configuration reveals a GOR of 4.7. • Effective heating of the HDH system was obtained through parabolic trough solar collector

Model-Based Extracted Water Desalination System for Carbon Sequestration

Energy Technology Data Exchange (ETDEWEB)

Dees, Elizabeth M. [General Electric Global Research Center, Niskayuna, NY (United States); Moore, David Roger [General Electric Global Research Center, Niskayuna, NY (United States); Li, Li [Pennsylvania State Univ., University Park, PA (United States); Kumar, Manish [Pennsylvania State Univ., University Park, PA (United States)

2017-05-28

Over the last 1.5 years, GE Global Research and Pennsylvania State University defined a model-based, scalable, and multi-stage extracted water desalination system that yields clean water, concentrated brine, and, optionally, salt. The team explored saline brines that ranged across the expected range for extracted water for carbon sequestration reservoirs (40,000 up to 220,000 ppm total dissolved solids, TDS). In addition, the validated the system performance at pilot scale with field-sourced water using GE’s pre-pilot and lab facilities. This project encompassed four principal tasks, in addition to Project Management and Planning: 1) identify a deep saline formation carbon sequestration site and a partner that are suitable for supplying extracted water; 2) conduct a techno-economic assessment and down-selection of pre-treatment and desalination technologies to identify a cost-effective system for extracted water recovery; 3) validate the downselected processes at the lab/pre-pilot scale; and 4) define the scope of the pilot desalination project. Highlights from each task are described below: Deep saline formation characterization The deep saline formations associated with the five DOE NETL 1260 Phase 1 projects were characterized with respect to their mineralogy and formation water composition. Sources of high TDS feed water other than extracted water were explored for high TDS desalination applications, including unconventional oil and gas and seawater reverse osmosis concentrate. Technoeconomic analysis of desalination technologies Techno-economic evaluations of alternate brine concentration technologies, including humidification-dehumidification (HDH), membrane distillation (MD), forward osmosis (FO), turboexpander-freeze, solvent extraction and high pressure reverse osmosis (HPRO), were conducted. These technologies were evaluated against conventional falling film-mechanical vapor recompression (FF-MVR) as a baseline desalination process. Furthermore, a

Energy Demand Comparison between Hollow Fiber Membrane Based Dehumidification and Evaporative Cooling Dehumidification Using TRNSYS

Directory of Open Access Journals (Sweden)

Jeachul Jang

2018-05-01

Full Text Available This communication presents the performance evaluation and comparative study between two different techniques: a membrane-based dehumidification system (MDS and evaporative cooling dehumidification (ECD for a typical climate of South Korea. Although there are different ways to dehumidify the air in living and work spaces, the membrane-based dehumidification system (MDS is the most effective way as it neither causes a change in the temperature nor harms the environment. Moreover, it consumes significantly less energy when compared to other methods. There are also limitations concerning products that are sensitive to temperature such as food and pharmaceutical products; the method of evaporative cooling dehumidification is not suitable for such applications. The present work demonstrated the excellent energy-saving performance of the membrane-based dehumidification system against evaporative cooling dehumidification by comparing the performance of these two systems during the rainy season using a transient system simulation. The results showed that the MDS helped to reduce the dehumidification load by more than 47.6% when compared to the ECD system, which is a significant achievement in this regard.

Liquid desiccant dehumidification and regeneration process to meet cooling and freshwater needs of desert greenhouses

KAUST Repository

Lefers, Ryan

2016-04-19

Agriculture accounts for ~70% of freshwater usage worldwide. Seawater desalination alone cannot meet the growing needs for irrigation and food production, particularly in hot, desert environments. Greenhouse cultivation of high-value crops uses just a fraction of freshwater per unit of food produced when compared with open field cultivation. However, desert greenhouse producers face three main challenges: freshwater supply, plant nutrient supply, and cooling of the greenhouse. The common practice of evaporative cooling for greenhouses consumes large amounts of fresh water. In Saudi Arabia, the most common greenhouse cooling schemes are fresh water-based evaporative cooling, often using fossil groundwater or energy-intensive desalinated water, and traditional refrigeration-based direct expansion cooling, largely powered by the burning of fossil fuels. The coastal deserts have ambient conditions that are seasonally too humid to support adequate evaporative cooling, necessitating additional energy consumption in the dehumidification process of refrigeration-based cooling. This project evaluates the use of a combined-system liquid desiccant dehumidifier and membrane distillation unit that can meet the dual needs of cooling and freshwater supply for a greenhouse in a hot and humid environment. © 2016 Balaban Desalination Publications. All rights reserved.

Air dehumidification and drying processes

Energy Technology Data Exchange (ETDEWEB)

Steiner, R.

1988-07-01

Details are given on the physical principles of air dehumidification and drying as well as on appropriate systems available on the market. Reference is made to dehumidification through condensation (intermittent compressor or electric auxiliary heater defrosting, reversible-circuit hot gas bypass defrosting), air drying through sorption (sorbents, regeneration through heat inputs), the operation of absorptive dryers (schematic sketches), and the change of state of air (Mollier h,x-diagramm). Practical examples refer to the dehumidification of storage rooms, archives, and waterworks as well as to air drying in the pharmaceutical industry, the pastry and candy industry, the food industry, and the drying (preservation) of turbines and generators during long standstill periods. A diagramm shows that while adsorption processes are efficient at temperatures below 80/sup 0/C, low-temperature dehumidification is efficient at temperatures above. (HWJ).

Desalination using spray tower and vapour compression refrigeration system

International Nuclear Information System (INIS)

Sathish Kumar, S.; Mani, A.

2006-01-01

A desalination system using a spray tower and Vapour Compression Refrigeration (VCR) system is proposed for obtaining fresh water from brackish water. In the spray tower, simultaneous heat and mass transfer take place between the brackish water and air, which results in the evaporation of the brackish water and humidification of the air. Fresh water is obtained from the humidified air by condensing the water vapour using a VCR system. Parametric studies were carried out to study the effect of various operational parameters on the fresh water production rate. (author)

Condensation irrigation a system for desalination and irrigation

International Nuclear Information System (INIS)

Lindblom, J.; Nordell, B

2006-01-01

condensation irrigation is a system for both desalination and irrigation. The principles is that humidified air is let into an underground horizontal pipe system, where the air is cooled by the ground and humidity falls out as fresh water. The humidification could e.g. be achieved by evaporation of seawater in solar stills or any other heat source. By using drainage pipes for underground air transportation the water percolates into the soil, thereby irrigating the land. This study focuses on drinking water production, which means that humid air is led into plan pipes where the condensed water is collected at the pipe endings. Numerical simulations gave a study-state diurnal mean water production of 1.8 kg per meter of pipe over a 50 m pipe. Shorter pipes result in a greater mean production rate. Since the heat transfer of drainage pipes would be greater, current study indicates that condensation irrigation is a promising method for desalination and irrigation. Performed studies in condensation irrigation started at LTU in 2003. Current paper reports the initial theoretical work on the system.(Author)

Practical use of solar heating-dehumidification dry kiln

Energy Technology Data Exchange (ETDEWEB)

Kobayashi, Yoshinori

1988-06-01

In order to decrease the energy cost for drying, a solar-dehumidification dry kiln which used the dehumidification dry process together with the solar thermal drier was developed and tested. In the daytime the drying temperature rose up to 60/sup 0/C in summer and 40/sup 0/C in winter, and it was kept higher by 15 to 20/sup 0/C than the outside temperature at night. Owing to the adoption of the combination of direct solar heating and exhausting highly humid air, it was not necessary to operate the dry kiln in the day time. Average electrical energy consumption which was consumed to 15% moisture content from the raw lumber was about 73kWh/m/sup 3/ in summer which was lowest, about 87kWh/m/sup 3/ in winter. Energy cost required for the solar dehumidification dry kiln is 1/2 to 2/3 of that of the conventional dehumidification dry kiln. The solar-dehumidification dry kiln has a merit of cheaper operating cost in the low energy cost and reduced drying time. (7 figs, 1 tab, 6 refs)

Modeling and simulation of a New Design of the SMCEC Desalination Unit Using Solar Energy

International Nuclear Information System (INIS)

Zhani, K.; Ben Bacha, H.

2009-01-01

The aim of this research is to parametrically study a new process working design with Humidification/Dehumidification (HD) technique using solar energy which is developed to ameliorate the production of the SMCEC unit (Solar Multiple Condensation Evaporation Cycle). The SMCEC unit is currently operating at Sfax's national engineering school in Tunisia. The improvement of the production consists in increasing the capacity of air to load water vapor with heating and subsequent humidification of air at the exit of the condensation tower instead of rejecting or recycling it. So, to attend our objective, we need to integrate into the SMCEC unit a flat plate solar air collector for heating air and a humidifier for its humidification. Then, the newly designed system is basically composed of a flat plate solar air collector, a flat plate solar water collector, a humidifier, an evaporation tower and a condensation tower. A general model based on heat and mass transfers in each component of the unit is developed in a steady state regime. The obtained set of ordinary differential equations is converted to a set of algebraic system of equations by the functional approximation method of orthogonal collocation. The developed model is used to investigate both the effect of different operating modes on the water condensation rate and the steady state behavior of each component of the unit and the entire system exposed to a variation of the entrance parameters and meteorological conditions.

The performance investigation of a temperature cascaded cogeneration system equipped with adsorption desalination unit

KAUST Repository

Myat, Aung

2013-02-01

This paper presents the performance investigation of a temperature cascaded cogeneration plant, shortly in TCCP, equipped with an efficient waste heat recovery system. The TCCP or cogeneration system produces four types of useful energy namely (i) electricity, (ii) steam, (iii) cooling, and (iv) dehumidification and distilled water by utilizing single energy source. The TCCP comprises a Capstone C30 micro-turbine that generates nominal capacity of 26 kW of electricity, a compact and efficient waste heat recovery system and a host of waste heatactivated devices namely (i) a steam generator, (ii) an absorption chiller, (iii) an adsorption desalination system, and (iv) a multi-bed desiccant dehumidifier. The analysis is performed under different operation conditions such as heat source temperatures, flow rates of heat transfer fluids and chilled water inlet temperatures. The only single heat source for TCCP is obtained from exhaust gas of micro-turbine and it is channeled to a series of waste heat recovery heat exchangers to steam and hot water at different temperatures. Hot water produced by such a compact heat exchangers is the driving heat source to produce steam of 15 kg/h, cooling of 2 Rton, dehumidification of 2 Rton, and distilled water of 0.7 m3/day. A set of experiments, both part load and full load, of micro-turbine is conducted to examine the electricity generation and the exhaust gas temperature. It is observed that energy utilization factor could achieve as high as 70% while fuel energy saving ratio is found to be 28%. © 2013 Desalination Publications. All rights reserved.

The performance investigation of a temperature cascaded cogeneration system equipped with adsorption desalination unit

KAUST Repository

Myat, Aung; Thu, Kyaw; Kim, Youngdeuk; Ng, K. C.

2013-01-01

This paper presents the performance investigation of a temperature cascaded cogeneration plant, shortly in TCCP, equipped with an efficient waste heat recovery system. The TCCP or cogeneration system produces four types of useful energy namely (i) electricity, (ii) steam, (iii) cooling, and (iv) dehumidification and distilled water by utilizing single energy source. The TCCP comprises a Capstone C30 micro-turbine that generates nominal capacity of 26 kW of electricity, a compact and efficient waste heat recovery system and a host of waste heatactivated devices namely (i) a steam generator, (ii) an absorption chiller, (iii) an adsorption desalination system, and (iv) a multi-bed desiccant dehumidifier. The analysis is performed under different operation conditions such as heat source temperatures, flow rates of heat transfer fluids and chilled water inlet temperatures. The only single heat source for TCCP is obtained from exhaust gas of micro-turbine and it is channeled to a series of waste heat recovery heat exchangers to steam and hot water at different temperatures. Hot water produced by such a compact heat exchangers is the driving heat source to produce steam of 15 kg/h, cooling of 2 Rton, dehumidification of 2 Rton, and distilled water of 0.7 m3/day. A set of experiments, both part load and full load, of micro-turbine is conducted to examine the electricity generation and the exhaust gas temperature. It is observed that energy utilization factor could achieve as high as 70% while fuel energy saving ratio is found to be 28%. © 2013 Desalination Publications. All rights reserved.

The performance of a temperature cascaded cogeneration system producing steam, cooling and dehumidification

KAUST Repository

Myat, Aung

2013-02-01

This paper discusses the performance of a temperature-cascaded cogeneration plant (TCCP), equipped with an efficient waste heat recovery system. The TCCP, also called a cogeneration system, produces four types of useful energy-namely, (i) electricity, (ii) steam, (iii) cooling and (iv) dehumidification-by utilizing single fuel source. The TCCP comprises a Capstone C-30 micro-turbine that generates nominal capacity of 26 kW of electricity, a compact and efficient waste heat recovery system and a host of waste-heat-activated devices, namely (i) a steam generator, (ii) an absorption chiller, (iii) an adsorption chiller and (iv) a multi-bed desiccant dehumidifier. The performance analysis was conducted under different operation conditions such as different exhaust gas temperatures. It was observed that energy utilization factor could be as high as 70% while fuel energy saving ratio was found to be 28%. © 2013 Desalination Publications.

Air dehumidification by membrane with cold water for manned spacecraft environmental control

Directory of Open Access Journals (Sweden)

Shang Yonghong

2017-01-01

Full Text Available The traditional condensation dehumidification method requires additional gas-liquid separation and water recovery process in the manned spacecraft humidity control system, which would increase weight and complexity of systems. A new membrane dehumidification with cold water is proposed, which uses water vapor partial pressure difference to promote water vapor transmembrane mass transfer for dehumidification. The permeability of the membrane was measured and the experimental results agree well with the theoretical calculations. Based on the simulation of dehumidification process of cold water-membrane, the influence of module structure and working condition on dehumidification performance was analyzed, which provided reference for the design of membrane module construct. It can be seen from the simulation and experiments that the cold water-membrane dehumidification can effectively reduce the thermal load of the manned spacecraft.

Humidification and secretion volume in mechanically ventilated patients.

Science.gov (United States)

Solomita, Mario; Palmer, Lucy B; Daroowalla, Feroza; Liu, Jeffrey; Miller, Dori; LeBlanc, Deniese S; Smaldone, Gerald C

2009-10-01

To determine potential effects of humidification on the volume of airway secretions in mechanically ventilated patients. Water vapor delivery from devices providing non-heated-wire humidification, heated-wire humidification, and heat and moisture exchanger (HME) were quantified on the bench. Then, patients requiring 24-hour mechanical ventilation were exposed sequentially to each of these humidification devices, and secretions were removed and measured by suctioning every hour during the last 4 hours of the 24-hour study period. In vitro water vapor delivery was greater using non-heated-wire humidification, compared to heated-wire humidification and HME. In vivo, a total of 9 patients were studied. Secretion volume following humidification by non-heated-wire humidification was significantly greater than for heated-wire humidification and HME (P=.004). The volume of secretions appeared to be linked to humidification, as greater water vapor delivery measured in vitro was associated with greater secretion volume in vivo.

Procedures for Calculating Residential Dehumidification Loads

Energy Technology Data Exchange (ETDEWEB)

Winkler, Jon [National Renewable Energy Lab. (NREL), Golden, CO (United States); Booten, Chuck [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2016-06-01

Residential building codes and voluntary labeling programs are continually increasing the energy efficiency requirements of residential buildings. Improving a building's thermal enclosure and installing energy-efficient appliances and lighting can result in significant reductions in sensible cooling loads leading to smaller air conditioners and shorter cooling seasons. However due to fresh air ventilation requirements and internal gains, latent cooling loads are not reduced by the same proportion. Thus, it's becoming more challenging for conventional cooling equipment to control indoor humidity at part-load cooling conditions and using conventional cooling equipment in a non-conventional building poses the potential risk of high indoor humidity. The objective of this project was to investigate the impact the chosen design condition has on the calculated part-load cooling moisture load, and compare calculated moisture loads and the required dehumidification capacity to whole-building simulations. Procedures for sizing whole-house supplemental dehumidification equipment have yet to be formalized; however minor modifications to current Air-Conditioner Contractors of America (ACCA) Manual J load calculation procedures are appropriate for calculating residential part-load cooling moisture loads. Though ASHRAE 1% DP design conditions are commonly used to determine the dehumidification requirements for commercial buildings, an appropriate DP design condition for residential buildings has not been investigated. Two methods for sizing supplemental dehumidification equipment were developed and tested. The first method closely followed Manual J cooling load calculations; whereas the second method made more conservative assumptions impacting both sensible and latent loads.

Humidification on Ventilated Patients: Heated Humidifications or Heat and Moisture Exchangers?

Science.gov (United States)

Cerpa, F; Cáceres, D; Romero-Dapueto, C; Giugliano-Jaramillo, C; Pérez, R; Budini, H; Hidalgo, V; Gutiérrez, T; Molina, J; Keymer, J

2015-01-01

The normal physiology of conditioning of inspired gases is altered when the patient requires an artificial airway access and an invasive mechanical ventilation (IMV). The endotracheal tube (ETT) removes the natural mechanisms of filtration, humidification and warming of inspired air. Despite the noninvasive ventilation (NIMV) in the upper airways, humidification of inspired gas may not be optimal mainly due to the high flow that is being created by the leakage compensation, among other aspects. Any moisture and heating deficit is compensated by the large airways of the tracheobronchial tree, these are poorly suited for this task, which alters mucociliary function, quality of secretions, and homeostasis gas exchange system. To avoid the occurrence of these events, external devices that provide humidification, heating and filtration have been developed, with different degrees of evidence that support their use.

Hollow Fiber Membrane Dehumidification Device for Air Conditioning System.

Science.gov (United States)

Zhao, Baiwang; Peng, Na; Liang, Canzeng; Yong, Wai Fen; Chung, Tai-Shung

2015-11-16

In order to provide a comfortable living and working environment indoors in tropical countries, the outdoor air often needs to be cooled and dehumidified before it enters the rooms. Membrane separation is an emerging technology for air dehumidification and it is based on the solution diffusion mechanism. Water molecules are preferentially permeating through the membranes due to its smaller kinetic diameter and higher condensability than the other gases. Compared to other dehumidification technologies such as direct cooling or desiccation, there is no phase transition involved in membrane dehumidification, neither the contact between the fresh air stream and the desiccants. Hence, membrane dehumidification would not only require less energy consumption but also avoid cross-contamination problems. A pilot scale air dehumidification system is built in this study which comprises nine pieces of one-inch PAN/PDMS hollow fiber membrane modules. A 150 h long-term test shows that the membrane modules has good water vapor transport properties by using a low vacuum force of only 0.78 bar absolute pressure at the lumen side. The water vapor concentration of the feed humid air decreases dramatically from a range of 18-22 g/m³ to a range of 13.5-18.3 g/m³. Most importantly, the total energy saving is up to 26.2% compared with the conventional air conditioning process.

Hollow Fiber Membrane Dehumidification Device for Air Conditioning System

Directory of Open Access Journals (Sweden)

Baiwang Zhao

2015-11-01

Full Text Available In order to provide a comfortable living and working environment indoors in tropical countries, the outdoor air often needs to be cooled and dehumidified before it enters the rooms. Membrane separation is an emerging technology for air dehumidification and it is based on the solution diffusion mechanism. Water molecules are preferentially permeating through the membranes due to its smaller kinetic diameter and higher condensability than the other gases. Compared to other dehumidification technologies such as direct cooling or desiccation, there is no phase transition involved in membrane dehumidification, neither the contact between the fresh air stream and the desiccants. Hence, membrane dehumidification would not only require less energy consumption but also avoid cross-contamination problems. A pilot scale air dehumidification system is built in this study which comprises nine pieces of one-inch PAN/PDMS hollow fiber membrane modules. A 150 h long-term test shows that the membrane modules has good water vapor transport properties by using a low vacuum force of only 0.78 bar absolute pressure at the lumen side. The water vapor concentration of the feed humid air decreases dramatically from a range of 18–22 g/m3 to a range of 13.5–18.3 g/m3. Most importantly, the total energy saving is up to 26.2% compared with the conventional air conditioning process.

Review of Desiccant Dehumidification Technology

Energy Technology Data Exchange (ETDEWEB)

Pesaran, A. A.

1994-10-01

This paper overviews applications of desiccant technology for dehumidifying commercial and institutional buildings. Because of various market, policy, and regulatory factors, this technology is especially attractive for dehumidification applications in the I990s.

Under-humidification and over-humidification during moderate induced hypothermia with usual devices.

Science.gov (United States)

Lellouche, François; Qader, Siham; Taille, Solenne; Lyazidi, Aissam; Brochard, Laurent

2006-07-01

In mechanically ventilated patients with induced hypothermia, the efficacy of heat and moisture exchangers and heated humidifiers to adequately humidify the airway is poorly known. The aim of the study was to assess the efficacy of different humidification devices during moderate hypothermia. Prospective, cross-over randomized study. Medical Intensive Care Unit in a University Hospital. Nine adult patients hospitalized after cardiac arrest in whom moderate hypothermia was induced (33 degrees C for 24[Symbol: see text]h). Patients were ventilated at admission (period designated "normothermia") with a heat and moisture exchanger, and were randomly ventilated during hypothermia with a heat and moisture exchanger, a heated humidifier, and an active heat and moisture exchanger. Core temperature, inspired and expired gas absolute and relative humidity were measured. Each system demonstrated limitations in its ability to humidify gases in the specific situation of hypothermia. Performances of heat and moisture exchangers were closely correlated to core temperature (r (2)[Symbol: see text]=[Symbol: see text]0.84). During hypothermia, heat and moisture exchangers led to major under-humidification, with absolute humidity below 25[Symbol: see text]mgH(2)O/l. The active heat and moisture exchanger slightly improved humidification. Heated humidifiers were mostly adequate but led to over-humidification in some patients, with inspiratory absolute humidity higher than maximal water content at 33 degrees C with a positive balance between inspiratory and expiratory water content. These results suggest that in the case of moderate hypothermia, heat and moisture exchangers should be used cautiously and that heated humidifiers may lead to over-humidification with the currently recommended settings.

Performance analysis of proposed hybrid air conditioning and humidification–dehumidification systems for energy saving and water production in hot and dry climatic regions

International Nuclear Information System (INIS)

Nada, S.A.; Elattar, H.F.; Fouda, A.

2015-01-01

Highlights: • Integrative air-conditioning (A/C) and humidification–dehumidification desalination systems are proposed. • Effects of operating parameters on the proposed systems are investigated. • System configurations that have the highest fresh water production rate, power saving and total cost saving are identified. - Abstract: Performance of integrative air-conditioning (A/C) and humidification–dehumidification desalination systems proposed for hot and dry climatic regions is theoretically investigated. The proposed systems aim to energy saving and systems utilization in fresh water production. Four systems with evaporative cooler and heat recovery units located at different locations are proposed, analyzed and evaluated at different operating parameters (fresh air ratio, supply air temperature and outside air wet bulb temperature). Other two basic systems are used as reference systems in proposed systems assessment. Fresh water production rate, A/C cooling capacity, A/C electrical power consumption, saving in power consumptions and total cost saving (TCS) parameters are used for systems evaluations and comparisons. The results show that (i) the fresh water production rates of the proposed systems increase with increasing fresh air ratio, supply air temperature and outdoor wet bulb temperature, (ii) powers saving of the proposed systems increase with increasing fresh air ratio and supply air temperature and decreasing of the outdoor air wet bulb temperature, (iii) locating the evaporative cooling after the fresh air mixing remarkably increases water production rate, and (vi) incorporating heat recovery in the air conditioning systems with evaporative cooling may adversely affect both of the water production rate and the total cost saving of the system. Comparison study has been presented to identify systems configurations that have the highest fresh water production rate, highest power saving and highest total cost saving. Numerical correlations for

Latent effectiveness of desiccant wheel: A silica gels- water system

International Nuclear Information System (INIS)

Rabah, A. A.; Mohamed, S. A.

2009-01-01

A latent heat effectiveness model in term of dimensionless groups? =f (NTU, m * ,Crm * ) for energy wheel has been analytically derived. The energy wheel is divided into humidification and dehumidification sections. For each section macroscopic mass differential equations for gas and the matrix were applied. In this process local latent effectiveness (? c ,? h ) for the humidification and dehumidification section of the wheel were obtained. The Latent effectiveness of the wheel is then derived form local effectiveness [? =f (? c ,? h)]. The model is compared with the existing experimental investigation and manufacturer data for energy wheel. More than 90% of the experimental data within a confidence limit of 95%. (Author)

Y-piece temperature and humidification during mechanical ventilation.

Science.gov (United States)

Solomita, Mario; Daroowalla, Feroza; Leblanc, Deniese S; Smaldone, Gerald C

2009-04-01

Practitioners often presume there is adequate humidification in the ventilator circuit if the Y-piece is at a specified temperature, but control of Y-piece temperature may be inadequate to ensure adequate humidification. In an in vitro bench model we measured water-vapor delivery with several heated humidification setups and a wide range of minute volume (V (E)) values. The setup included a condenser, hygrometry, and thermometer. First, we calibrated the system with a point-source humidifier and water pump. Then we tested the water-vapor delivery during non-heated-wire humidification and during heated-wire humidification with a temperature gradient of +3 degrees C, 0 degrees C, and -3 degrees C between the humidifier and the Y-piece. We compared the results to 2 recommended humidification values: 100% saturated (absolute humidity 44 mg H(2)O/L) gas at 37 degrees C (saturated/37 degrees C); and 75% saturated (absolute humidity 33 mg H(2)O/L), which is the humidity recommended by the International Organization for Standardization (the ISO standard). In all the experiments the setup was set to provide 35 degrees C at the Y-piece. Our method for measuring water-vapor delivery closely approximated the amount delivered by a calibrated pump, but slightly underestimated the water-vapor delivery in all the experiments and the whole V (E) range. At all V (E) values, water-vapor delivery during non-heated-wire humidification matched or exceeded saturated/37 degrees C and was significantly greater than that during heated-wire humidification. During heated-wire humidification, water-vapor delivery varied with the temperature gradient and did not reach saturated/37 degrees C at V (E) > 6 L/min. Water-vapor delivery with the negative temperature gradient was below the ISO standard. Maintaining temperature at one point in the inspiratory circuit (eg, Y-piece), does not ensure adequate water-vapor delivery. Other factors (humidification system, V (E), gradient setting) are critical

Numerical study of a water distillation system using solar energy

International Nuclear Information System (INIS)

Zarzoum, K.; Zhani, K.; Bacha, H. Ben

2016-01-01

This paper tackles an optimization approach in order to boost the fresh water production of a new design of a solar still which is located at Sfax engineering national school in Tunisia. This optimization approach is based upon the above mentioned design's improvement by coupling the conventional solar still into at a condenser, solar air and water collector and humidifier. This new concept of a distiller solar still using humidification- dehumidification processes (HD) is exploited for the desalination purpose. As a result of this work, the humidification- dehumidification processes have an essential effect in improving the solar still performance. Performance has been predicted theoretically in terms of water and inner glass cover temperatures, the inlet temperature of air and water of the new concept of distiller on water condensation rate and fresh water production. A general model based on heat and mass transfers in each component of the unit has been developed in steady dynamic regime. The developed model is used, simulating the HD system, to investigate the influence of the meteorological and operating parameters on the system productivity. The obtained set of ordinary differential equations has been converted to a set of algebraic system of equations by the functional approximation method of orthogonal collocation. The developed model is used to simulate the HD system in order to investigate the steady state behavior of each component of the unit and the entire system exposed to a variation of the entrance parameters and meteorological conditions. The obtained results were compared with those of other studies and the comparison gives a good validity of the present results

Numerical study of a water distillation system using solar energy

Energy Technology Data Exchange (ETDEWEB)

Zarzoum, K.; Zhani, K. [Sfax University, (Turkey); Bacha, H. Ben [Prince Sattam Bin Abdulaziz University, Alkharj (Saudi Arabia)

2016-02-15

This paper tackles an optimization approach in order to boost the fresh water production of a new design of a solar still which is located at Sfax engineering national school in Tunisia. This optimization approach is based upon the above mentioned design's improvement by coupling the conventional solar still into at a condenser, solar air and water collector and humidifier. This new concept of a distiller solar still using humidification- dehumidification processes (HD) is exploited for the desalination purpose. As a result of this work, the humidification- dehumidification processes have an essential effect in improving the solar still performance. Performance has been predicted theoretically in terms of water and inner glass cover temperatures, the inlet temperature of air and water of the new concept of distiller on water condensation rate and fresh water production. A general model based on heat and mass transfers in each component of the unit has been developed in steady dynamic regime. The developed model is used, simulating the HD system, to investigate the influence of the meteorological and operating parameters on the system productivity. The obtained set of ordinary differential equations has been converted to a set of algebraic system of equations by the functional approximation method of orthogonal collocation. The developed model is used to simulate the HD system in order to investigate the steady state behavior of each component of the unit and the entire system exposed to a variation of the entrance parameters and meteorological conditions. The obtained results were compared with those of other studies and the comparison gives a good validity of the present results.

Artificial humidification for the mechanically ventilated patient.

Science.gov (United States)

Selvaraj, N

Caring for patients who are mechanically ventilated poses many challenges for critical care nurses. It is important to humidify the patient's airways artificially to prevent complications such as ventilator-associated pneumonia. There is no gold standard to determine which type of humidification is best for patients who are artificially ventilated. This article provides an overview of commonly used artificial humidification for mechanically ventilated patients and discusses nurses' responsibilities in caring for patients receiving artificial humidification.

Humidification during invasive and noninvasive mechanical ventilation: 2012.

Science.gov (United States)

Restrepo, Ruben D; Walsh, Brian K

2012-05-01

We searched the MEDLINE, CINAHL, and Cochrane Library databases for articles published between January 1990 and December 2011. The update of this clinical practice guideline is based on 184 clinical trials and systematic reviews, and 10 articles investigating humidification during invasive and noninvasive mechanical ventilation. The following recommendations are made following the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) scoring system: 1. Humidification is recommended on every patient receiving invasive mechanical ventilation. 2. Active humidification is suggested for noninvasive mechanical ventilation, as it may improve adherence and comfort. 3. When providing active humidification to patients who are invasively ventilated, it is suggested that the device provide a humidity level between 33 mg H(2)O/L and 44 mg H(2)O/L and gas temperature between 34°C and 41°C at the circuit Y-piece, with a relative humidity of 100%. 4. When providing passive humidification to patients undergoing invasive mechanical ventilation, it is suggested that the HME provide a minimum of 30 mg H(2)O/L. 5. Passive humidification is not recommended for noninvasive mechanical ventilation. 6. When providing humidification to patients with low tidal volumes, such as when lung-protective ventilation strategies are used, HMEs are not recommended because they contribute additional dead space, which can increase the ventilation requirement and P(aCO(2)). 7. It is suggested that HMEs are not used as a prevention strategy for ventilator-associated pneumonia.

Humidification during Mechanical Ventilation in the Adult Patient

OpenAIRE

Al Ashry, Haitham S.; Modrykamien, Ariel M.

2014-01-01

Humidification of inhaled gases has been standard of care in mechanical ventilation for a long period of time. More than a century ago, a variety of reports described important airway damage by applying dry gases during artificial ventilation. Consequently, respiratory care providers have been utilizing external humidifiers to compensate for the lack of natural humidification mechanisms when the upper airway is bypassed. Particularly, active and passive humidification devices have rapidly evo...

[Airway humidification practices in Chilean intensive care units].

Science.gov (United States)

Retamal, Jaime; Castillo, Juan; Bugedo, Guillermo; Bruhn, Alejandro

2012-11-01

In patients with an artificial airway, inspired gases can be humidified and heated using a passive (heat and moisture exchange filter - HMEF), or an active system (heated humidifier). To assess how humidification is carried out and what is the usual clinical practice in this field in Chilean intensive care units (ICUs). A specific survey to evaluate humidification system features as well as caregivers' preferences regarding humidification systems, was carried out on the same day in all Chilean ICUs. Fifty-five ICUs were contacted and 44 of them completed the survey. From a total of 367 patients, 254 (69%) required humidification because they were breathing through an artificial airway. A heated humidifier was employed only in 12 patients (5%). Forty-three ICUs (98%) used HMEF as their routine humidification system. In 52% of surveyed ICUs, heated humidifiers were not available. In Chile the main method to humidify and heat inspired gases in patients with an artificial airway is the HMEF. Although there are clear indications for the use of heated humidifiers, they are seldom employed.

Microbial desalination cells for energy production and desalination

KAUST Repository

Kim, Younggy; Logan, Bruce E.

2013-01-01

Microbial desalination cells (MDCs) are a new, energy-sustainable method for using organic matter in wastewater as the energy source for desalination. The electric potential gradient created by exoelectrogenic bacteria desalinates water by driving

Desiccant wheels for air humidification: An experimental and numerical analysis

International Nuclear Information System (INIS)

De Antonellis, Stefano; Intini, Manuel; Joppolo, Cesare Maria; Molinaroli, Luca; Romano, Francesco

2015-01-01

Highlights: • The use of desiccant wheel to humidify an air stream is investigated. • Air humidification is obtained by extracting water vapour from outdoor air. • Experimental tests in winter humidification conditions are performed. • The design of the proposed humidification system is numerically analyzed. • Effects of boundary conditions on humidification capacity are investigated. - Abstract: In this work the use of a desiccant wheel for air humidification is investigated through a numerical and experimental approach. In the proposed humidification system, water vapour is adsorbed from outdoor environment and it is released directly to the air stream supplied to the building. Such a system can be an interesting alternative to steam humidifiers in hospitals or, more generally, in applications where air contamination is a critical issue and therefore adiabatic humidifiers are not allowed. Performance of the proposed system is deeply investigated and optimal values of desiccant wheel configuration parameters are discussed. It is shown that in the investigated conditions, which are representative of Southern Europe winter climate, the system can properly match the latent load of the building. Finally, power consumption referred to the primary source of the proposed humidification system is compared to the one of steam humidifiers. The present analysis is carried out through experimental tests of a desiccant wheel in winter humidification conditions and through a phenomenological model of the device, based on heat and mass transfer equations.

Domiciliary humidification improves lung mucociliary clearance in patients with bronchiectasis.

Science.gov (United States)

Hasani, A; Chapman, T H; McCool, D; Smith, R E; Dilworth, J P; Agnew, J E

2008-01-01

Inspired air humidification has been reported to show some benefit in bronchiectatic patients. We have investigated the possibility that one effect might be to enhance mucociliary clearance. Such enhancement might, if it occurs, help to lessen the risks of recurrent infective episodes. Using a radioaerosol technique, we measured lung mucociliary clearance before and after 7 days of domiciliary humidification. Patients inhaled high flow saturated air at 37 degrees C via a patient-operated humidification nasal inhalation system for 3 h per day. We assessed tracheobronchial mucociliary clearance from the retention of (99m)Tc-labelled polystyrene tracer particles monitored for 6 h, with a follow-up 24-h reading. Ten out of 14 initially recruited patients (age 37-75 years; seven females) completed the study (two withdrew after their initial screening and two prior to the initial clearance test). Seven patients studied were non-smokers; three were ex-smokers (1-9 pack-years). Initial tracer radioaerosol distribution was closely similar between pre- and post-treatment. Following humidification, lung mucociliary clearance significantly improved, the area under the tracheobronchial retention curve decreased from 319 +/- 50 to 271 +/- 46%h (p humidification treatment improved lung mucociliary clearance in our bronchiectatic patients. Given this finding plus increasing laboratory and clinical interest in humidification mechanisms and effects, we believe further clinical trials of humidification therapy are desirable, coupled with analysis of humidification effects on mucus properties and transport.

An experimental study of a solar humidifier for HDD systems

International Nuclear Information System (INIS)

Ghazal, M.T.; Atikol, U.; Egelioglu, F.

2014-01-01

Highlights: • Solar water and air heating and humidification processes have been merged in one unit. • The effectiveness of the solar humidifier was improved. • Bubbles regeneration enhanced the mass and heat transfer to air. • Reflector mirror enhanced the productivity of the system. - Abstract: This paper investigates the performance of a solar humidification prototype suitable for using in humidification dehumidification desalination (HDD) systems. This unit replaces the solar air heater, solar water heater and the evaporator of the traditional HDD plants, facilitating compact system designs. The prototype is composed of a solar collector, filled with water, through which air is forced to travel upwards in the form of bubbles. Experiments are conducted under the weather conditions of North Cyprus. It is discovered that the air temperature is found to approach the hot water temperature in the collector (thus increasing the vapor carrying capacity) and the relative humidity is raised to almost 100% at the exit. The collector inlet and outlet temperatures and relative humidity values are recorded for different flow rates in the period between the 1st and the 14th of December, 2012. It was found that for an average intensity of solar radiation of 700 W/m 2 and a mass flow rate of 12.6 kg/h of air; the amount of water evaporated was 0.75 kg/h on a square meter basis. Introduction of a reflector mirror at the bottom side of the humidifier increased the average absolute humidity by 32%

Influence of humidification on comfort during noninvasive ventilation with a helmet.

Science.gov (United States)

Ueta, Kazuyoshi; Tomita, Toshiji; Uchiyama, Akinori; Ohta, Noriyuki; Iguchi, Naoya; Goto, Yukiko; Fujino, Yuji

2013-05-01

To evaluate optimal humidifier water temperature when using a helmet for noninvasive ventilation. Twenty-eight healthy individuals underwent 8 cm H2O CPAP ventilation with FIO2 of 0.21 and 0.5. Each was sequentially tested in the following order: using the helmet without humidification at ambient temperature; with humidification with unheated chamber water; and with humidification with the chamber water at 31°C, 34°C, and 37°C. At each setting, after a 20 min stabilization period, measurements were taken. Comfort level at each setting was evaluated using a visual analog scale rated zero (least comfortable) to 10 (most comfortable). Temperature and relative and absolute humidity inside the helmet increased; however, the comfort scores significantly decreased as the humidification chamber water temperature increased. Regardless of the FIO2, statistically significantly highest comfort scores were obtained when humidification water, with and without active humidification, was at ambient temperature. Unacceptable absolute humidity was obtained only without humidification at room temperature when FIO2 was 0.5. With the clinical use of a helmet, for patient comfort and mucosal humidification during CPAP, the most desirable conditions are likely to be obtained by humidifying without heating, that is by leaving the water in the humidifier chamber at room temperature.

Triple-bore hollow fiber membrane contactor for liquid desiccant based air dehumidification

KAUST Repository

Bettahalli Narasimha, Murthy Srivatsa

2016-04-26

Dehumidification is responsible for a large part of the energy consumption in cooling systems in high humidity environments worldwide. Improving efficiency is therefore essential. Liquid desiccants offer a promising solution for dehumidification, as desired levels of humidity removal could be easily regulated. The use of membrane contactors in combination with liquid desiccant is attractive for dehumidification because they prevent direct contact between the humid air and the desiccant, removing both the potential for desiccant carryover to the air and the potential for contamination of the liquid desiccant by dust and other airborne materials, as well as minimizing corrosion. However, the expected additional mass transport barrier of the membrane surface can lower the expected desiccation rate per unit of desiccant surface area. In this context, hollow fiber membranes present an attractive option for membrane liquid desiccant contactors because of their high surface area per unit volume. We demonstrate in this work the performance of polyvinylidene fluoride (PVDF) based triple-bore hollow fiber membranes as liquid desiccant contactors, which are permeable to water vapor but impermeable to liquid water, for dehumidification of hot and humid air.

Characteristics of PEMFC operating at high current density with low external humidification

International Nuclear Information System (INIS)

Fan, Linhao; Zhang, Guobin; Jiao, Kui

2017-01-01

Highlights: • PEMFC with low humidity and high current density is studied by numerical simulation. • At high current density, water production lowers external humidification requirement. • A steady anode circulation status without external humidification is demonstrated. • The corresponding detailed internal water transfer path in the PEMFC is illustrated. • Counter-flow is superior to co-flow at low anode external humidification. - Abstract: A three-dimensional multiphase numerical model for proton exchange membrane fuel cell (PEMFC) is developed to study the fuel cell performance and water transport properties with low external humidification. The results show that the sufficient external humidification is necessary to prevent the polymer electrolyte dehydration at low current density, while at high current density, the water produced in cathode CL is enough to humidify the polymer electrolyte instead of external humidification by flowing back and forth between the anode and cathode across the membrane. Furthermore, a steady anode circulation status without external humidification is demonstrated in this study, of which the detailed internal water transfer path is also illustrated. Additionally, it is also found that the water balance under the counter-flow arrangement is superior to co-flow at low anode external humidification.

Humidification during mechanical ventilation in the adult patient.

Science.gov (United States)

Al Ashry, Haitham S; Modrykamien, Ariel M

2014-01-01

Humidification of inhaled gases has been standard of care in mechanical ventilation for a long period of time. More than a century ago, a variety of reports described important airway damage by applying dry gases during artificial ventilation. Consequently, respiratory care providers have been utilizing external humidifiers to compensate for the lack of natural humidification mechanisms when the upper airway is bypassed. Particularly, active and passive humidification devices have rapidly evolved. Sophisticated systems composed of reservoirs, wires, heating devices, and other elements have become part of our usual armamentarium in the intensive care unit. Therefore, basic knowledge of the mechanisms of action of each of these devices, as well as their advantages and disadvantages, becomes a necessity for the respiratory care and intensive care practitioner. In this paper, we review current methods of airway humidification during invasive mechanical ventilation of adult patients. We describe a variety of devices and describe the eventual applications according to specific clinical conditions.

Radiant floor cooling coupled with dehumidification systems in residential buildings: A simulation-based analysis

International Nuclear Information System (INIS)

Zarrella, Angelo; De Carli, Michele; Peretti, Clara

2014-01-01

Highlights: • The floor radiant cooling in a typical apartment is analyzed. • Dehumidification devices, fan-coil and mechanical ventilation are compared. • The results are analyzed in terms of both thermal comfort and energy consumption. • The energy consumption of the dehumidifiers is higher than that of other systems. • The mechanical ventilation decreases the moisture level better than other systems. - Abstract: The development of radiant cooling has stimulated an interest in new systems based on coupling ventilation with radiant cooling. However, radiant cooling systems may cause condensation to form on an active surface under warm and humid conditions during the cooling season. This phenomenon occurs when surface temperature falls below dew point. To prevent condensation, air humidity needs to be reduced with a dehumidification device or a mechanical ventilation system. There are two main options to achieve this. The first is to use dehumidification devices that reduce humidity, but are not coupled with ventilation, i.e. devices that handle room air and leave air change to infiltrations. The second is to combine a mechanical ventilation system with dehumidifying finned coils. This study analyzes the floor radiant cooling of a typical residential apartment within a multi-storey building in three Italian climate zones by means of a detailed simulation tool. Five systems were compared in terms of both indoor thermal comfort and energy consumption: radiant cooling without dehumidification; radiant cooling with a soft dehumidification device; radiant cooling with a dehumidification device which also supplies sensible cooling; radiant cooling coupled with fan coils; and radiant cooling with a mechanical ventilation system which dehumidifies and cools

Home-based humidification for mucositis in patients undergoing radical radiotherapy: preliminary report.

Science.gov (United States)

Morton, Randall P; Thomson, Vicki C; Macann, Andrew; Gerard, Catherine M; Izzard, Mark; Hay, K David

2008-04-01

Oropharyngeal mucositis is a frequent, severe complication of local irradiation for tumours in the head and neck. We postulated that heated humidification of inspired air via a nasal interface may palliate symptoms of mucositis by reducing the discomfort associated with dry, sticky secretions. We sought to review the effect of home-based humidification on hospital admissions and the patient reported experience of that humidification. This study was a retrospective review. A historical (control) group of patients did not receive home humidification at any stage (n = 55) and a study group (n = 53) received home humidification at or after the onset of grade 3 mucositis. A questionnaire was sent to study group patients to obtain information about their experience of using the humidifier at home. There were no demographic differences between the study and control groups, but the study group had significantly more advanced cancer (stage IV; p = .0307) and significantly higher total fractions and days treated (p humidification were admitted after starting that use (p humidification was of benefit, and 81% stated that it relieved mouth or throat pain. Humidification of inspired gas offers a simple, drug-free option for managing a number of the adverse mucosal effects of radiation and chemoradiation in head and neck cancer patients.

An experimental study of solar desalination using free jets and an auxiliary hot air stream

Science.gov (United States)

Eid, Eldesouki I.; Khalaf-Allah, Reda A.; Dahab, Mohamed A.

2018-04-01

An experimental study for a solar desalination system based on jet-humidification with an auxiliary perpendicular hot air stream was carried out at Suez city, Egypt 29.9668°N, 32.5498°E. The tests were done from May to October 2016. The effects of nozzles situations and nozzle diameter with and without hot air stream on fresh water productivity were monitored. The results show that; the lateral and downward jets from narrow nozzles have more productivities than other situations. The hot air stream has to be adapted at a certain flow rate to get high values of productivity. The system productivity is (5.6 L/m 2 ), the estimated cost is (0.030063 / L) and the efficiency is 32.8%.

ZVI (Fe0) desalination: catalytic partial desalination of saline aquifers

Science.gov (United States)

Antia, David D. J.

2018-05-01

Globally, salinization affects between 100 and 1000 billion m3 a-1 of irrigation water. The discovery that zero valent iron (ZVI, Fe0) could be used to desalinate water (using intra-particle catalysis in a diffusion environment) raises the possibility that large-scale in situ desalination of aquifers could be undertaken to support agriculture. ZVI desalination removes NaCl by an adsorption-desorption process in a multi-stage cross-coupled catalytic process. This study considers the potential application of two ZVI desalination catalyst types for in situ aquifer desalination. The feasibility of using ZVI catalysts when placed in situ within an aquifer to produce 100 m3 d-1 of partially desalinated water from a saline aquifer is considered.

Processing method of radioactive gaseous waste

International Nuclear Information System (INIS)

Sugisaki, Haruo.

1996-01-01

In the present invention, a dehumidification device incorporating hollow membranes having a large steam permeation efficiency is used. The humidification device is sucked by an extractor, and gases are passed through the hollow membranes. A portion (for example, 20%) of the primary gases dried by the humidification device is supplied to the outside of the hollow membranes for purging, and sucked at a pressure lower than that on the primary side by utilizing vacuum pressure of a main condenser. With such a constitution, steam permeation is improved by increasing the steam differential pressure between the primary and secondary sides of the hollow thread membrane thereby enabling to remove steam content in the off-gases most efficiently. Accordingly to the present invention, neither dehumidification cooler nor refrigerator is necessary to save the control for the plant. (T.M.)

Microbial desalination cells for energy production and desalination

KAUST Repository

Kim, Younggy

2013-01-01

Microbial desalination cells (MDCs) are a new, energy-sustainable method for using organic matter in wastewater as the energy source for desalination. The electric potential gradient created by exoelectrogenic bacteria desalinates water by driving ion transport through a series of ion-exchange membranes (IEMs). The specific MDC architecture and current conditions substantially affect the amount of wastewater needed to desalinate water. Other baseline conditions have varied among studies making comparisons of the effectiveness of different designs problematic. The extent of desalination is affected by water transport through IEMs by both osmosis and electroosmosis. Various methods have been used, such as electrolyte recirculation, to avoid low pH that can inhibit exoelectrogenic activity. The highest current density in an MDC to date is 8.4A/m2, which is lower than that produced in other bioelectrochemical systems. This implies that there is a room for substantial improvement in desalination rates and overall performance. We review here the state of the art in MDC design and performance, safety issues related to the use of MDCs with wastewater, and areas that need to be examined to achieve practical application of this new technology. © 2012 Elsevier B.V.

Is humidification always necessary during noninvasive ventilation in the hospital?

Science.gov (United States)

Branson, Richard D; Gentile, Michael A

2010-02-01

Noninvasive ventilation (NIV) is a standard of care for the treatment of exacerbation of chronic obstructive pulmonary disease, to prevent intubation and reduce morbidity and mortality. The need for humidification of NIV gas is controversial. Some unique aspects of NIV conspire to alter the delivered humidity and airway function. In the presence of air leaks, unidirectional air flow dries the airways and increases airway resistance. Patient comfort is also a critical issue, as tolerance of NIV is often tied to patient comfort. This paper provides the arguments for and against routine humidification during NIV in the hospital setting. Data from clinical research demonstrate the effects of delivered humidification on relevant physiologic variables. The impact of humidification on NIV success/failure remains speculative.

Performance study of a heat pump driven and hollow fiber membrane-based two-stage liquid desiccant air dehumidification system

International Nuclear Information System (INIS)

Zhang, Ning; Yin, Shao-You; Zhang, Li-Zhi

2016-01-01

Graphical abstract: A heat pump driven, hollow fiber membrane-based two-stage liquid desiccant air dehumidification system. - Highlights: • A two-stage hollow fiber membrane based air dehumidification is proposed. • It is heat pump driven liquid desiccant system. • Performance is improved 20% upon single stage system. • The optimal first to second stage dehumidification area ratio is 1.4. - Abstract: A novel compression heat pump driven and hollow fiber membrane-based two-stage liquid desiccant air dehumidification system is presented. The liquid desiccant droplets are prevented from crossing over into the process air by the semi-permeable membranes. The isoenthalpic processes are changed to quasi-isothermal processes by the two-stage dehumidification processes. The system is set up and a model is proposed for simulation. Heat and mass capacities in the system, including the membrane modules, the condenser, the evaporator and the heat exchangers are modeled in detail. The model is also validated experimentally. Compared with a single-stage dehumidification system, the two-stage system has a lower solution concentration exiting from the dehumidifier and a lower condensing temperature. Thus, a better thermodynamic system performance is realized and the COP can be increased by about 20% under the typical hot and humid conditions in Southern China. The allocations of heat and mass transfer areas in the system are also investigated. It is found that the optimal regeneration to dehumidification area ratio is 1.33. The optimal first to second stage dehumidification area ratio is 1.4; and the optimal first to second stage regeneration area ratio is 1.286.

Artificial humidification for the mechanically ventilated patient

OpenAIRE

Selvaraj, Nelson

2010-01-01

Caring for patients who are mechanically ventilated poses many\\ud challenges for critical care nurses. It is important to humidify the\\ud patient’s airways artificially to prevent complications such as\\ud ventilator-associated pneumonia. There is no gold standard to\\ud determine which type of humidification is best for patients who\\ud are artificially ventilated. This article provides an overview of\\ud commonly used artificial humidification for mechanically ventilated\\ud patients and discuss...

Humidification of inspired gases during mechanical ventilation.

Science.gov (United States)

Gross, J L; Park, G R

2012-04-01

Humidification of inspired gas is mandatory for all mechanically ventilated patients to prevent secretion retention, tracheal tube blockage and adverse changes occurring to the respiratory tract epithelium. However, the debate over "ideal" humidification continues. Several devices are available that include active and passive heat and moisture exchangers and hot water humidifiers Each have their advantages and disadvantages in mechanically ventilated patients. This review explores each device in turn and defines their role in clinical practice.

Nasal inflammation in sleep apnoea patients using CPAP and effect of heated humidification.

Science.gov (United States)

Koutsourelakis, I; Vagiakis, E; Perraki, E; Karatza, M; Magkou, C; Kopaka, M; Roussos, C; Zakynthinos, S

2011-03-01

Nasal continuous positive airway pressure (CPAP) can cause undesirable nasal symptoms, such as congestion to obstructive sleep apnoea (OSA) patients, whose symptoms can be attenuated by the addition of heated humidification. However, neither the nature of nasal symptoms nor the effect of heated humidification on nasal pathophysiology and pathology are convincingly known. 20 patients with OSA on nasal CPAP who exhibited symptomatic nasal obstruction were randomised to receive either 3 weeks of CPAP treatment with heated humidification or 3 weeks of CPAP treatment with sham-heated humidification, followed by 3 weeks of the opposite treatment, respectively. Nasal symptom score, nasal resistance, nasal lavage interleukin-6, interleukin-12 and tumour necrosis factor-α and nasal mucosa histopathology were assessed at baseline and after each treatment arm. Heated humidification in comparison with sham-heated humidification was associated with decrease in nasal symptomatology, resistance and lavage cytokines, and attenuation of inflammatory cell infiltration and fibrosis of the nasal mucosa. In conclusion, nasal obstruction of OSA patients on CPAP treatment is inflammatory in origin and the addition of heated humidification decreases nasal resistance and mucosal inflammation.

Advances in desalination technology

International Nuclear Information System (INIS)

Pankratz, T.M.

2005-01-01

Seawater desalination has been the cornerstone of the Middle East's water supply strategy since the mid-1950s, and most of the installed desalination capacity is still provided by multistage flash evaporators. But, desalination is changing. In fact, the term 'desalination' is no longer limited to seawater applications; desalination technologies are now routinely employed to desalinate brackish groundwater and repurify municipal effluents. Recent advances in desalination technology have simultaneously reduced costs while dramatically improving performance and reliability to the point where desalination technologies now compete with 'conventional' treatment processes in many applications. New commercial strategies and a realisation of the economies-of-scale have led to further improvements in plant economics, and an increase in the size of plants now being developed and constructed. This presentation reviews advances in membrane and membrane pretreatment systems, energy recovery devices, materials of construction, hybrid process configurations, increased unit capacities, and the use of public-private partnerships; all of which have led to reduced capital and operating costs, enabling desalination to be economically competitive with traditional treatment options. Advances in desalination technology have resulted in better performances, lower capital and operating costs, and increased application of desalination systems. In the face of increased water shortages and growing costs of 'conventional treatment', this trend will certainly continue. (author)

Routine use of humidification with nasal continuous positive airway pressure.

Science.gov (United States)

Worsnop, C J; Miseski, S; Rochford, P D

2010-09-01

Heated humidification can reduce nasal symptoms caused by continuous positive airway pressure (CPAP) treatment, but its routine use has not been studied over the medium term in a randomized controlled trial. The aim of this study is to determine if heated humidification would reduce nasal symptoms and improve adherence with CPAP treatment in all patients with sleep apnoea irrespective of whether they had nasal symptoms initially. A randomized, parallel group design. Patients were treated for 3 months with a Fisher & Paykel HC201 pump with built-in heated humidification, or with the heater disabled and without water. Adherence was measured with a timer built into the pumps. Nasal symptoms were measured with a 10-cm visual analogue scale. There were 25 in the humidification group and 29 in the non-humidification group. After 12 weeks mean (standard deviation) adherence with CPAP was 4.7 (2.4) and 4.5 (2.2) hours per night respectively. Nasal symptoms that were reduced were nose blocked* 6 (12), 18 (26); sneezing* 4 (8), 15 (25); dry nose* 8 (12), 24 (33); stuffy nose* 7 (14), 22(31); dry mouth* 13 (18), 33(36); and runny nose* 6 (17), 14 (29). Parameters marked with an asterisk '*' had P humidification with CPAP in all patients with sleep apnoea reduced nasal symptoms, but did not improve adherence. © 2010 The Authors. Internal Medicine Journal © 2010 Royal Australasian College of Physicians.

Effect of cathode gas humidification on performance and durability of Solid Oxide Fuel Cells

DEFF Research Database (Denmark)

Nielsen, Jimmi; Hagen, Anke; Liu, Yi-Lin

2010-01-01

The effect of cathode inlet gas humidification was studied on single anode supported Solid Oxide Fuel Cells (SOFC's). The studied cells were Risø 2 G and 2.5 G. The former consists of a LSM:YSZ composite cathode, while the latter consists of a LSCF:CGO composite cathode on a CGO protection layer....... The humidification effect was found to be dependent on both the degree of humidification and the cathode polarization. No significant effect of humidification was found at OCV which rules out the possibility of a traditional poisoning effect with a blocking of active sites. Post-mortem high resolution FEG......-SEM analysis showed clear changes at and around the cathode/electrolyte contact area. In contrast to Risø 2 G cells, a very high tolerance towards humidification of cathode gas air was observed for Risø 2.5 G cells with no detectable effect of humidification even when the humidification was as high as 12.8 mol%...

Investigation on a two-stage solar liquid-desiccant (LiBr) dehumidification system assisted by CaCl2 solution

International Nuclear Information System (INIS)

Xiong, Z.Q.; Dai, Y.J.; Wang, R.Z.

2009-01-01

A two-stage solar powered liquid-desiccant dehumidification system, for which two kinds of desiccant solution (lithium chloride and calcium bromide) are fed to the two dehumidification stages separately, has been studied. In the studied system air moisture (latent) load is separately removed by a pre-dehumidifier using cheap calcium chloride (CaCl 2 ) and a main dehumidifier using stable lithium bromide (LiBr). Side-effect of mixing heat rejected during dehumidification process is considerably alleviated by an indirect evaporative cooling unit added between the two dehumidification stages. The feasibility of high-desiccant concentration difference achieved by reusing desiccant solution to dehumidify air and regenerating desiccant repeatedly is analyzed. By increasing desiccant concentration difference, desiccant storage capacity is effectively explored. It is found that the pre-dehumidification effect of CaCl 2 solution is significant in high ambient humidity condition. Also seen is that the desiccant investment can be decreased by 53%, though the cost of equipments is somewhat increased, and the Tcop and COP of the proposed system can reach 0.97 and 2.13, respectively

Nuclear power desalinating complex with IRIS reactor plant and Russian distillation desalinating unit

International Nuclear Information System (INIS)

Kostin, V. I.; Panov, Yu.K.; Polunichev, V. I.; Fateev, S. A.; Gureeva, L. V.

2004-01-01

This paper has been prepared as a result of Russian activities on the development of nuclear power desalinating complex (NPDC) with the IRIS reactor plant (RP). The purpose of the activities was to develop the conceptual design of power desalinating complex (PDC) and to evaluate technical and economical indices, commercial attractiveness and economical efficiency of PDC based on an IRIS RP with distillation desalinating plants. The paper presents the main results of studies as applied to dual-purpose PDC based on IRIS RP with different types of desalinating plants, namely: characteristics of nuclear power desalinating complex based on IRIS reactor plant using Russian distillation desalinating technologies; prospective options of interface circuits of the IRIS RP with desalinating plants; evaluations of NPDC with IRIS RP output based on selected desalinating technologies for water and electric power supplied to the grid; cost of water generated by NPDC for selected interface circuits made by the IAEA DEEP code as well as by the Russian TEO-INVEST code; cost evaluation results for desalinated water of PDC operating on fossil fuel and conditions for competitiveness of the nuclear PDC based on IRIS RP compared with analog desalinating complexes operating on fossil fuel.(author)

Airway Humidification Reduces the Inflammatory Response During Mechanical Ventilation.

Science.gov (United States)

Jiang, Min; Song, Jun-Jie; Guo, Xiao-Li; Tang, Yong-Lin; Li, Hai-Bo

2015-12-01

Currently, no clinical or animal studies have been performed to establish the relationship between airway humidification and mechanical ventilation-induced lung inflammatory responses. Therefore, an animal model was established to better define this relationship. Rabbits (n = 40) were randomly divided into 6 groups: control animals, sacrificed immediately after anesthesia (n = 2); dry gas group animals, subjected to mechanical ventilation for 8 h without humidification (n = 6); and experimental animals, subjected to mechanical ventilation for 8 h under humidification at 30, 35, 40, and 45°C, respectively (n = 8). Inflammatory cytokines in the bronchi alveolar lavage fluid (BALF) were measured. The integrity of the airway cilia and the tracheal epithelium was examined by scanning and transmission electron microscopy, respectively. Peripheral blood white blood cell counts and the wet to dry ratio and lung pathology were determined. Dry gas group animals showed increased tumor necrosis factor alpha levels in BALF compared with control animals (P humidification temperature was increased to 40°C. Scanning and transmission electron microscopy analysis revealed that cilia integrity was maintained in the 40°C groups. Peripheral white blood cell counts were not different among those groups. Compared with control animals, the wet to dry ratio was significantly elevated in the dry gas group (P humidification at 40°C resulted in reduced pathologic injury compared with the other groups based on the histologic score. Pathology and reduced inflammation observed in animals treated at 40°C was similar to that observed in the control animals, suggesting that appropriate humidification reduced inflammatory responses elicited as a consequence of mechanical ventilation, in addition to reducing damage to the cilia and reducing water loss in the airway. Copyright © 2015 by Daedalus Enterprises.

Membrane humidification--a new method for humidification of respiratory gases in ventilator treatment of neonates.

Science.gov (United States)

Hanssler, L; Tennhoff, W; Roll, C

1992-01-01

A humidifier system for neonatology that functions according to the 'membrane humidification' principle was subjected to a performance test in our laboratory. Humidification and heating of the respiratory gases took place in a module consisting of a net of hollow fibres placed inside the incubator. In 18 measurement combinations flow, respiratory gas temperature, and incubator temperature were varied. At respiratory gas temperatures within the range of 33-37 degrees C the minimum international standard for the absolute air humidity in the respiratory gas was achieved or exceeded in all measurements. No controlled clinical tests regarding the importance and long term effects of different temperatures and different humidity levels in the inspiratory air are yet available for the ventilation treatment of neonates. PMID:1444554

Heated air humidification versus cold air nebulization in newly tracheostomized patients.

Science.gov (United States)

Birk, Richard; Händel, Alexander; Wenzel, Angela; Kramer, Benedikt; Aderhold, Christoph; Hörmann, Karl; Stuck, Boris A; Sommer, J Ulrich

2017-12-01

After tracheostomy, the airway lacks an essential mechanism for warming and humidifying the inspired air with the consequent functional impairment and discomfort. The purpose of this study was to compare airway hydration with cold-air nebulization versus heated high-flow humidification on medical interventions and tracheal ciliary beat frequency (CBF). Newly tracheostomized patients (n = 20) were treated either with cold-air nebulization or heated humidification. The number of required tracheal suctioning procedures to clean the trachea and tracheal CBF were assessed. The number of required suctions per day was significantly lower in the heated humidification group with medians 3 versus 5 times per day. Mean CBF was significantly higher in the heated humidification group (6.36 ± 1.49 Hz) compared to the cold-air nebulization group (3.99 ± 1.39 Hz). The data suggest that heated humidification enhanced mucociliary transport leading to a reduced number of required suctioning procedures in the trachea, which may improve postoperative patient care. © 2017 The Authors Head & Neck Published by Wiley Periodicals, Inc.

Comparison of two humidification systems for long-term noninvasive mechanical ventilation.

Science.gov (United States)

Nava, S; Cirio, S; Fanfulla, F; Carlucci, A; Navarra, A; Negri, A; Ceriana, P

2008-08-01

There is no consensus concerning the best system of humidification during long-term noninvasive mechanical ventilation (NIMV). In a technical pilot randomised crossover 12-month study, 16 patients with stable chronic hypercapnic respiratory failure received either heated humidification or heat and moisture exchanger. Compliance with long-term NIMV, airway symptoms, side-effects and number of severe acute pulmonary exacerbations requiring hospitalisation were recorded. Two patients died. Intention-to-treat statistical analysis was performed on 14 patients. No significant differences were observed in compliance with long-term NIMV, but 10 out of 14 patients decided to continue long-term NIMV with heated humidification at the end of the trial. The incidence of side-effects, except for dry throat (significantly more often present using heat and moisture exchanger), hospitalisations and pneumonia were not significantly different. In the present pilot study, the use heated humidification and heat and moisture exchanger showed similar tolerance and side-effects, but a higher number of patients decided to continue long-term noninvasive mechanical ventilation with heated humidification. Further larger studies are required in order to confirm these findings.

A New Method for Water Desalination Using Microbial Desalination Cells

KAUST Repository

Cao, Xiaoxin

2009-09-15

Current water desalination techniques are energy intensive and some use membranes operated at high pressures. It is shownhere that water desalination can be accomplished without electrical energy input or high water pressure by using a source of organic matter as the fuel to desalinate water. A microbial fuel cell was modified by placing two membranes between the anode and cathode, creating a middle chamber for water desalination between the membranes. An anion exchange membrane was placed adjacent to the anode, and a cation exchange membrane was positioned next to the cathode. When current was produced by bacteria on the anode, ionic species in the middle chamber were transferred into the two electrode chambers, desalinating the water in the middle chamber. Proof-of-concept experiments for this approach, using what we call a microbial desalination cell (MDC), was demonstrated using water at different initial salt concentrations (5, 20, and 35 g/L) with acetate used as the substrate for the bacteria. The MDC produced a maximum of 2 W/m2 (31 W/m3) while at the same time removing about 90% of the salt in a single desalination cycle. As the salt was removed from the middle chamber the ohmic resistance of the MDC (measured using electrochemical impedance spectroscopy) increased from 25 Ω to 970 Ω at the end of the cycle. This increased resistance was reflected by a continuous decrease in the voltage produced over the cycle. These results demonstrate for the first time the possibility for a new method for water desalination and power production that uses only a source of biodegradable organic matter and bacteria. © 2009 American Chemical Society.

Theoretical design strategies of bipolar membrane fuel cell with enhanced self-humidification behavior

Science.gov (United States)

Li, Qiushi; Gong, Jian; Peng, Sikan; Lu, Shanfu; Sui, Pang-Chieh; Djilali, Ned; Xiang, Yan

2016-03-01

The bipolar membrane fuel cells (BPMFCs), which have a unique acid-alkaline jointed membrane electrode assembly (MEA) structure, have demonstrated their great potential for self-humidification during operation. Although the self-humidification ability of such bipolar membranes (BPMs) has recently been validated by a one-dimensional BPM model, the transport mechanism and the formation of self-humidification in the MEAs are not well understood. In the present study, a two-dimensional cross-channel MEA model is developed to elucidate the mechanisms and enhancement of water transport on self-humidification with comprehensive consideration of the three electrochemical reaction zones. The water-formation interface model has been successfully investigated by theoretical and experimental interface reaction kinetics, streamlines of water flux present the formation process and mechanism of self-humidification. A critical current (voltage) value, beyond which self-humidification is initiated, is identified. It is also found that such critical current (voltage) can be adjusted by changing the membrane thickness and the water uptake property of the ionomer. It is concluded that fabricating BPMs with proper membrane thickness and water uptake property are effective strategies to enhance the water management and cell performance in BPMFCs.

Adsorption desalination: An emerging low-cost thermal desalination method

KAUST Repository

Ng, K. C.; Thu, Kyaw; Kim, Youngdeuk; Chakraborty, Anutosh; Amy, Gary L.

2013-01-01

Desalination, other than the natural water cycle, is hailed as the panacea to alleviate the problems of fresh water shortage in many water stressed countries. However, the main drawback of conventional desalination methods is that they are energy

Desalination processes and technologies

International Nuclear Information System (INIS)

Furukawa, D.H.

1996-01-01

Reasons of the development of desalination processes, the modern desalination technologies, such as multi-stage flash evaporation, multi-effect distillation, reverse osmosis, and the prospects of using nuclear power for desalination purposes are discussed. 9 refs

EPB standard EN ISO 52016: calculation of the building’s energy needs for heating and cooling, internal temperatures and heating and cooling load

NARCIS (Netherlands)

Dijk, H.A.L. van; Spiekman, M.E.; Hoes-van Oeffelen, E.C.M.

2016-01-01

EN ISO 52016-1 presents a coherent set of calculation methods at different levels of detail, for the (sensible) energy needs for the space heating and cooling and (latent) energy needs (de)humidification of a building and/or internal temperatures and heating and/or cooling loads, including the

Reducing the negative vocal effects of superficial laryngeal dehydration with humidification.

Science.gov (United States)

Levendoski, Elizabeth Erickson; Sundarrajan, Anusha; Sivasankar, M Preeti

2014-07-01

Environmental humidification is a simple, cost-effective method believed to reduce superficial laryngeal drying. This study sought to validate this belief by investigating whether humidification treatment would reduce the negative effects of superficial laryngeal dehydration on phonation threshold pressure (PTP). Phonation threshold pressure data analysis may be vulnerable to bias because of lack of investigator blinding. Consequently, this study investigated the extent of PTP analysis reliability between unblinded and blinded investigators. Healthy male and female adults were assigned to a vocal fatigue (n = 20) or control group (n = 20) based on their responses to a questionnaire. PTP was assessed after 2 hours of mouth breathing in low humidity (dehydration challenge), following a 5-minute break in ambient humidity, and after 2 hours of mouth breathing in high humidity (humidification). PTP significantly increased following the laryngeal dehydration challenge. After humidification, PTP returned toward baseline. These effects were observed in both subject groups. PTP measurements were highly correlated between the unblinded and blinded investigator. Humidification may be an effective approach to decrease the detrimental voice effects of superficial laryngeal dehydration. These data lay the foundation for future investigations aimed at preventing and treating the negative voice changes associated with chronic, surface laryngeal drying.

Microbial desalination cells packed with ion-exchange resin to enhance water desalination rate.

Science.gov (United States)

Morel, Alexandre; Zuo, Kuichang; Xia, Xue; Wei, Jincheng; Luo, Xi; Liang, Peng; Huang, Xia

2012-08-01

A novel configuration of microbial desalination cell (MDC) packed with ion-exchange resin (R-MDC) was proposed to enhance water desalination rate. Compared with classic MDC (C-MDC), an obvious increase in desalination rate (DR) was obtained by R-MDC. With relatively low concentration (10-2 g/L NaCl) influents, the DR values of R-MDC were about 1.5-8 times those of C-MDC. Ion-exchange resins packed in the desalination chamber worked as conductor and thus counteracted the increase in ohmic resistance during treatment of low concentration salt water. Ohmic resistances of R-MDC stabilized at 3.0-4.7 Ω. By contrast, the ohmic resistances of C-MDC ranged from 5.5 to 12.7 Ω, which were 55-272% higher than those of R-MDC. Remarkable improvement in desalination rate helped improve charge efficiency for desalination in R-MDC. The results first showed the potential of R-MDC in the desalination of water with low salinity. Copyright © 2012 Elsevier Ltd. All rights reserved.

A Desalination Battery

KAUST Repository

Pasta, Mauro; Wessells, Colin D.; Cui, Yi; La Mantia, Fabio

2012-01-01

Water desalination is an important approach to provide fresh water around the world, although its high energy consumption, and thus high cost, call for new, efficient technology. Here, we demonstrate the novel concept of a "desalination battery", which operates by performing cycles in reverse on our previously reported mixing entropy battery. Rather than generating electricity from salinity differences, as in mixing entropy batteries, desalination batteries use an electrical energy input to extract sodium and chloride ions from seawater and to generate fresh water. The desalination battery is comprised by a Na 2-xMn 5O 10 nanorod positive electrode and Ag/AgCl negative electrode. Here, we demonstrate an energy consumption of 0.29 Wh l -1 for the removal of 25% salt using this novel desalination battery, which is promising when compared to reverse osmosis (∼ 0.2 Wh l -1), the most efficient technique presently available. © 2012 American Chemical Society.

A desalination battery.

Science.gov (United States)

Pasta, Mauro; Wessells, Colin D; Cui, Yi; La Mantia, Fabio

2012-02-08

Water desalination is an important approach to provide fresh water around the world, although its high energy consumption, and thus high cost, call for new, efficient technology. Here, we demonstrate the novel concept of a "desalination battery", which operates by performing cycles in reverse on our previously reported mixing entropy battery. Rather than generating electricity from salinity differences, as in mixing entropy batteries, desalination batteries use an electrical energy input to extract sodium and chloride ions from seawater and to generate fresh water. The desalination battery is comprised by a Na(2-x)Mn(5)O(10) nanorod positive electrode and Ag/AgCl negative electrode. Here, we demonstrate an energy consumption of 0.29 Wh l(-1) for the removal of 25% salt using this novel desalination battery, which is promising when compared to reverse osmosis (~ 0.2 Wh l(-1)), the most efficient technique presently available. © 2012 American Chemical Society

A Desalination Battery

KAUST Repository

Pasta, Mauro

2012-02-08

Water desalination is an important approach to provide fresh water around the world, although its high energy consumption, and thus high cost, call for new, efficient technology. Here, we demonstrate the novel concept of a "desalination battery", which operates by performing cycles in reverse on our previously reported mixing entropy battery. Rather than generating electricity from salinity differences, as in mixing entropy batteries, desalination batteries use an electrical energy input to extract sodium and chloride ions from seawater and to generate fresh water. The desalination battery is comprised by a Na 2-xMn 5O 10 nanorod positive electrode and Ag/AgCl negative electrode. Here, we demonstrate an energy consumption of 0.29 Wh l -1 for the removal of 25% salt using this novel desalination battery, which is promising when compared to reverse osmosis (∼ 0.2 Wh l -1), the most efficient technique presently available. © 2012 American Chemical Society.

Design of nuclear desalination concentrate plant by using zero discharge desalination concept for Bangka Island

International Nuclear Information System (INIS)

Erlan Dewita, Siti Alimah

2015-01-01

Nuclear desalination is a process to separate salt of seawater by using nuclear energy. Desalination concentrate is a problem in nuclear desalination. Desalination concentrate is sometimes discharged directly into the seawater, therefore it can affects the water quality of beach and rise negative effects on the biota in the vicinity of the output. ZDD (Zero Discharge Desalination) concept can be applied to minimized environment impact. This study is conducted by using PWR type NPP as nuclear heat source and using ZDD concept to process desalination waste. ZDD is a concept for processing of desalination concentrate into salt and chemical products which have economic values. Objectives of this study is to design nuclear desalination concentrate processing plant in Bangka Island. The methodology is literature assessment and calculation with excel programme. The results of this study shows that the main the products are NaCl (pharmaceutical salt) and cakes BaSO4, Mg(OH)2BaCO3 as by products. (author)

A new prototype of an electronic jet-ventilator and its humidification system

Science.gov (United States)

Kraincuk, Paul; Kepka, Anton; Ihra, Gerald; Schabernig, Christa; Aloy, Alexander

1999-01-01

Background: Adequate humidification in long-term jet ventilation is a critical aspect in terms of clinical safety. Aim: To assess a prototype of an electronic jet-ventilator and its humidification system. Methods: Forty patients with respiratory insufficiency were randomly allocated to one of four groups. The criterion for inclusion in this study was respiratory insufficiency exhibiting a Murray score above 2. The four groups of patients were ventilated with three different respirators and four different humidification systems. Patients in groups A and B received superimposed high-frequency jet ventilation (SHFJV) by an electronic jet-ventilator either with (group A) or without (group B) an additional humidification system. Patients in group C received high-frequency percussive ventilation (HFPV) by a pneumatic high-frequency respirator, using a hot water humidifier for warming and moistening the inspiration gas. Patients in group D received conventional mechanical ventilation using a standard intensive care unit respirator with a standard humidification system. SHFJV and HFPV were used for a period of 100 h (4days). Results: A significantly low inspiration gas temperature was noted in patients in group B, initially (27.2 ± 2.5°C) and after 2 days (28.0 ± 1.6°C) (P humidification associated with jet ventilation can be fully prevented by using this new jet-ventilator. These data were sustained by nondeteriorating MIS values at the end of the 4-day study period in groups A, C and D. PMID:11056732

Active humidification with Boussignac CPAP: in vitro study of a new method.

Science.gov (United States)

Alonso-Iñigo, José M; Almela, Amadeo; Albert, Alejandro; Carratalá, José M; Fas, María J

2013-04-01

To carry out an in vitro study of Boussignac CPAP valve performance with a new humidification method, using a heated humidifier. Two heated humidifiers were evaluated: Fisher & Paykel MR850, and Covidien Kendall Aerodyne 2000. Baseline measurements were taken in all experimental conditions without humidification. The Boussignac valve was adapted to the input of the humidification chamber. The system was connected to a test lung to assess the degree of pressurization. Hygrometric and pressure measurements were performed with the following gas flows: 10, 20, 30 and 40 L/min. The mean values of pressure generated by the Boussignac valve were 1.99 ± 0.02, 6.97 ± 0.05, 16.61 ± 0.08 and 21.24 ± 0.08 cm H2O, 10, 20, 30 and 40 L/min, respectively, no differences being detected between study groups. Overall absolute humidity was significantly greater with a heated humidifier than without humidification (range 40.01 ± 0.57-25.46 ± 0.49 compared to 0.16 ± 0.13 mgH2O/L, P humidification yielded humidity values above 25 mg H2O/L regardless of the heated humidifier and flow used. Pressurization values remained constant in each experimental situation and were not influenced by adding humidification. These data open up the possibility of using Boussignac CPAP on different types of patients, with different interfaces and for long periods of time.

Adsorption desalination: An emerging low-cost thermal desalination method

KAUST Repository

Ng, K. C.

2013-01-01

Desalination, other than the natural water cycle, is hailed as the panacea to alleviate the problems of fresh water shortage in many water stressed countries. However, the main drawback of conventional desalination methods is that they are energy intensive. In many instances, they consumed electricity, chemicals for pre- and post-treatment of water. For each kWh of energy consumed, there is an unavoidable emission of Carbon Dioxide (CO2) at the power stations as well as the discharge of chemically-laden brine into the environment. Thus, there is a motivation to find new direction or methods of desalination that consumed less chemicals, thermal energy and electricity.This paper describes an emerging and yet low cost method of desalination that employs only low-temperature waste heat, which is available in abundance from either the renewable energy sources or exhaust of industrial processes. With only one heat input, the Adsorption Desalination (AD) cycle produces two useful effects, i.e., high grade potable water and cooling. In this article, a brief literature review, the theoretical framework for adsorption thermodynamics, a lumped-parameter model and the experimental tests for a wide range of operational conditions on the basic and the hybrid AD cycles are discussed. Predictions from the model are validated with measured performances from two pilot plants, i.e., a basic AD and the advanced AD cycles. The energetic efficiency of AD cycles has been compared against the conventional desalination methods. Owing to the unique features of AD cycle, i.e., the simultaneous production of dual useful effects, it is proposed that the life cycle cost (LCC) of AD is evaluated against the LCC of combined machines that are needed to deliver the same quantities of useful effects using a unified unit of $/MWh. In closing, an ideal desalination system with zero emission of CO2 is presented where geo-thermal heat is employed for powering a temperature-cascaded cogeneration plant. �

First results of a coated heat exchanger for the use in dehumidification and cooling processes

International Nuclear Information System (INIS)

Munz, Gunther M.; Bongs, C.; Morgenstern, A.; Lehmann, S.; Kummer, H.; Henning, H.-M.; Henninger, Stefan K.

2013-01-01

In this work a novel solar driven dehumidification and cooling system is presented. The core components of this combined system are a sorptive dehumidification device based on high performance sorptive coatings and a novel evacuated tube solar air collector providing the driving heat. The essential part of the system is the coated heat exchanger. The chosen adsorbent is attached to the heat exchanger surface by a newly developed coating technique. Besides a brief description of the novel components and the experimental setup, the development of the aluminum heat exchanger, the coating procedure and scale up for geometries comparable to the heat exchanger in the dehumidification setup, as well as a first characterization of a small-sized coated heat exchanger regarding water uptake and dehumidification performance are presented. For estimating an overall system performance, a 2-dimensional thermodynamic model was applied, using the parameters in focus for the development of heat exchanger, coating and demonstration system. Highlights: • A novel developed technology is applied for sorptive coating of heat exchangers. • Upscaling to dimensions of 100 × 100 × 400 mm 3 was successful. • A small scale heat exchanger was coated and characterized showing good results. • Evaluation of adsorbents and simulation of system performance were carried out. • SAPO-34 gives best performance for driving temperatures of 100 °C and above

Preparation of Natural Zeolite for Air Dehumidification in Food Drying

Directory of Open Access Journals (Sweden)

Mohamad Djaeni

2015-03-01

Full Text Available Drying with air dehumidification with solid adsorbent improves the quality of food product as well as energy efficiency. The natural zeolite is one of adsorbent having potential to adsorb the water.  Normally, the material was activated to open the pore, remove the organic impurities, and increase Si/Al rate. Hence, it can enhance the adsorbing capacity. This research studied the activation of natural zeolite mined from Klaten, Indonesia as air dehumidification for food drying. Two different methods were used involving activation by heat and NaOH introduction.  As indicators, the porosity and water loaded were evaluated. Results showed both methods improved the adsorbing capacity significantly. With NaOH, the adsorbing capacity was higher. The simple test in onion and corn drying showed the presence of activated natural zeolite can speed up water evaporation positively. This performance was also comparable with Zeolite 3A

Economical analysis of the spray drying process by pre-dehumidification of the inlet air

Energy Technology Data Exchange (ETDEWEB)

Madeira, A.N.; Camargo, J.R. [University of Taubate (UNITAU), SP (Brazil). Mechanical Engineering Dept.

2009-07-01

Spray drying is a dehumidification process by atomization in a closed chamber that aims to remove moisture of a product by heat and mass transfer from the product's contained water to the air that, in this process is previously heated. This paper presents a case study for an industry that produces food ingredients. The current process applied in the product to heat the air can uses one of these two systems: a direct heating process that burns liquid petroleum gas in contact with the inlet air or indirect heating that uses a heat exchanger which heat the air. This heating system consumes 90% of the total process energy. However, this inlet air can reach the dehumidifier with high moisture from the atmosphere condition requesting, in this case, more energy consumption according to the year's seasons. This paper promotes a utilization study of the current process through the installation of a pre-dehumidification device of the inlet air and shows a study to three different dehumidification systems that means by refrigeration, adsorption and actual comparing their performance in an energetic and economical point of view. The goals of this study are to analyze the capacity of moisture removing of each removing device, the influence of moisture variation of the inlet air in the process as well as the economic impact of each device in the global system. It concludes that the utilization of dehumidification devices can eliminate the heating system reducing this way the energy consumption. Moreover it promotes the increasing of moisture gradient between the inlet air and the product optimizing the drying process and increasing the global energy efficiency in the global system. Choosing the most appropriate system for the pre-dehumidification device depends on the desired initial and final moisture content of the product, but applying pre-dehumidifiers at the inlet air promotes an energetic optimization in the spray drying process. (author)

Energy-Saving Benefits of Adiabatic Humidification in the Air Conditioning Systems of Semiconductor Cleanrooms

Directory of Open Access Journals (Sweden)

Min-Suk Jo

2017-11-01

Full Text Available This paper aimed to evaluate the applicability of adiabatic humidification in the heating, ventilation, and air conditioning (HVAC systems of semiconductor cleanrooms. Accurate temperature and humidity control are essential in semiconductor cleanrooms and high energy consumption steam humidification is commonly used. Therefore, we propose an adiabatic humidification system employing a pressurized water atomizer to reduce the energy consumption. The annual energy consumption of three different HVAC systems were analyzed to evaluate the applicability of adiabatic humidification. The studied cases were as follows: (1 CASE 1: a make-up air unit (MAU with a steam humidifier, a dry cooling coil (DCC, and a fan filter unit (FFU; (2 CASE 2: a MAU with the pressurized water atomizer, a DCC, and a FFU; and (3 CASE 3: a MAU, a DCC, and a FFU, and the pressurized water atomizer installed in the return duct. The energy saving potential of adiabatic humidification over steam humidification has been proved, with savings of 8% and 23% in CASE 2 and CASE 3 compared to CASE 1, respectively. Furthermore, the pressurized water atomizer installed in the return duct exhibits greater energy saving effect than when installed in the MAU.

A thermodynamic perspective to study energy performance of vacuum-based membrane dehumidification

KAUST Repository

Bui, Thuan Duc; Kum Ja, M.; Gordon, Jeffrey M.; Ng, Kim Choon; Chua, Kian Jon

2017-01-01

In humid environments, decoupling the latent and sensible cooling loads - dehumidifying - can significantly improve chiller efficiency. Here, a basic limit for dehumidification efficiency is established from fundamental thermodynamics

Effect of hygroscopic materials on water vapor permeation and dehumidification performance of poly(vinyl alcohol) membranes

KAUST Repository

Bui, T. D.

2017-01-16

In this study, two hygroscopic materials, inorganic lithium chloride (LiCl) and organic triethylene glycol (TEG) were separately added to poly(vinyl alcohol) (PVA) to form blend membranes for air dehumidification. Water vapor permeation, dehumidification performance and long-term durability of the membranes were studied systematically. Membrane hydrophilicity and water vapor sorbability increased significantly with higher the hygroscopic material contents. Water vapor permeance of the membranes increased with both added hygroscopic material and absorbed water. Water permeation energy varied from positive to negative with higher hygroscopic content. This observation is attributed to a lower diffusion energy and a relatively constant sorption energy when hygroscopic content increases. Comparatively, PVA/TEG has less corrosive problems and is more environmentally friendly than PVA/LiCl. A membrane with PVA/TEG is observed to be highly durable and is suitable for dehumidification applications.

A heat pump driven and hollow fiber membrane-based liquid desiccant air dehumidification system: Modeling and experimental validation

International Nuclear Information System (INIS)

Zhang, Li-Zhi; Zhang, Ning

2014-01-01

A compression heat pump driven and membrane-based liquid desiccant air dehumidification system is presented. The dehumidifier and the regenerator are made of two hollow fiber membrane bundles packed in two shells. Water vapor can permeate through these membranes effectively, while the liquid desiccant droplets are prevented from cross-over. Simultaneous heating and cooling of the salt solution are realized with a heat pump system to improve energy efficiency. In this research, the system is built up and a complete modeling is performed for the system. Heat and mass transfer processes in the membrane modules, as well as in the evaporator, the condenser, and other key components are modeled in detail. The whole model is validated by experiment. The performances of SDP (specific dehumidification power), dehumidification efficiency, EER (energy efficiency ratio) of heat pump, and the COP (coefficient of performance) of the system are investigated numerically and experimentally. The results show that the model can predict the system accurately. The dehumidification capabilities and the energy efficiencies of the system are high. Further, it performs well even under the harsh hot and humid South China weather conditions. - Highlights: • A membrane-based and heat pump driven air dehumidification system is proposed. • A real experimental set up is built and used to validate the model for the whole system. • Performance under design and varying operation conditions is investigated. • The system performs well even under harsh hot and humid conditions

A thermodynamic perspective to study energy performance of vacuum-based membrane dehumidification

KAUST Repository

Bui, Thuan Duc

2017-05-13

In humid environments, decoupling the latent and sensible cooling loads - dehumidifying - can significantly improve chiller efficiency. Here, a basic limit for dehumidification efficiency is established from fundamental thermodynamics. This is followed by the derivation of how this limit is modified when the pragmatic constraint of a finite flux must be accommodated. These limits allow one to identify promising system modifications, and to quantify their impact. The focus is on vacuum-based membrane dehumidification. New high-efficiency configurations are formulated, most notably, by coupling pumping with condensation. More than an order-of-magnitude improvement in efficiency is achievable. It is contingent on water vapor exiting at its saturation pressure rather than at ambient pressure. Sensitivity studies to recovery ratio, temperature, relative humidity and membrane selectivity are also presented.

[Effects of two different methods for airway humidification for patients with tracheostomy: a Meta-analysis].

Science.gov (United States)

Wang, Jing; Pi, Hongying

2016-01-01

To evaluate the effects of two different kinds of airway humidification for tracheostomy patients, and to provide their relevant clinical effect and suggestions for their use. Online databases, including PubMed, EMBASE, JBI evidence-based nursing center library, the Cochrane Library, and Chinese databases (CNKI, Wanfang database, VIP, CBM) were searched systematically up to March 2015. Randomized controlled trials (RCTs) were considered eligible for inclusion if the following criteria were met: no history of respiratory tract infection; satisfactory nutritional status; tracheotomy performed; 18 years older. Two different humidification methods were used. Continuous airway humidification was used in the experiment group, while intermittent airway humidification was used in the control group. Two qualified reviewers reviewed the original articles, evaluating the quality of articles, and data were extracted independently. The enrolled RCTs were analyzed by Meta-analysis. A total of nine RCTs were included, containing 631 cases, among them 316 cases in expertment group, and 315 cases in control group. Continuous airway humidification was shown to be able to reduce the incidence of irritable cough [odds ratio (OR) = 0.20, 95% confidence interval (95%CI) = 0.12-0.34, P humidification for tracheostomy patients. Because the number of including articles was relative small, and the quality of some articles was poor, it is impossible to draw a reliable conclusion that continuous airway humidification could lower the incidence of complications for patients undergone tracheostomy.

General Overview of Desalination Technology

International Nuclear Information System (INIS)

Ari-Nugroho

2004-01-01

Desalination, as discussed in this journal, refers to a water treatment process that removes salts from water. Desalination can be done in a number of ways, but the result is always the same : fresh water is produced from brackish or seawater. The quality of distillate water is indicated by the contents of Total Dissolved Solid (TDS) in it, the less number of TDS contents in it, the highest quality of distillate water it has. This article describes the general analysis of desalination technologies, the varies of water, operation and maintenance of the plant, and general comparison between desalination technologies. Basically, there are two common technologies are being used, i.e. thermal and membrane desalination, which are Multi Effect Distillation (MED), Multi Stage Flash (MSF) and Reverse Osmosis (RO), respectively. Both technologies differ from the energy source. Thermal desalination needs heat source from the power plant, while membrane desalination needs only the electricity to run the pumps. In thermal desalination, the vapour coming from boiling feedwater is condensate, this process produces the lowest saline water, about 10 part per million (ppm). The membrane technology uses semipermeable membrane to separate fresh water from salt dissolve. This technology produces the fresh water about 350-500 ppm. (author)

Mask humidity during CPAP: influence of ambient temperature, heated humidification and heated tubing.

Science.gov (United States)

Nilius, Georg; Domanski, Ulrike; Schroeder, Maik; Woehrle, Holger; Graml, Andrea; Franke, Karl-Josef

2018-01-01

Mucosal drying during continuous positive airway pressure (CPAP) therapy is problematic for many patients. This study assessed the influence of ambient relative humidity (rH) and air temperature (T) in winter and summer on mask humidity during CPAP, with and without mask leak, and with or without heated humidification ± heated tubing. CPAP (8 and 12 cmH 2 O) without humidification (no humidity [nH]), with heated humidification controlled by ambient temperature and humidity (heated humidity [HH]) and HH plus heated tubing climate line (CL), with and without leakage, were compared in 18 subjects with OSA during summer and winter. The absolute humidity (aH) and the T inside the mask during CPAP were significantly lower in winter versus summer under all applied conditions. Overall, absolute humidity differences between summer and winter were statistically significant in both HH and CL vs. nH ( p humidification or with standard HH. Clinically-relevant reductions in aH were documented during CPAP given under winter conditions. The addition of heated humidification, using a heated tube to avoid condensation is recommended to increase aH, which could be useful in CPAP users complaining of nose and throat symptoms.

Experimental study of a cascade solar still coupled with a humidification–dehumidification system

International Nuclear Information System (INIS)

Farshchi Tabrizi, Farshad; Khosravi, Meisam; Shirzaei Sani, Iman

2016-01-01

Graphical abstract: In this study, coupling of a cascade solar still with a humidification–dehumidification system investigated experimentally. In addition, the effects of different operating conditions and configurations on thermal performance and productivity of the under investigation solar system were studied. - Highlights: • We investigate coupling of a cascade solar still with a humidification–dehumidification system. • The effects of different operating conditions on thermal performance were studied. • Temperature and flow rate of feed water as well as air process flow rate had undeniable effects on the productivity. • Coupling several CSS systems with just one HD system to maximize the productivity. • Enhancing daily productivity of coupling system from 28% to 141% for 40–150 ml/min flow rates, respectively. - Abstract: In this study, coupling of a cascade solar still with a humidification–dehumidification system was investigated experimentally under the climatological conditions of Zahedan (Latitude: 29.49, Longitude: 60.87), Iran. The inclined solar stills produce distillated and hot water simultaneously. In addition, the effects of different operating conditions and configurations on thermal performance and productivity of the solar system were studied. The effect of feed water and air flow rates on the daily productivity of HD system in different conditions such as feed water temperature has been investigated. The daily productivity of cascade solar still with and without HD system at different flow rates is investigated. Moreover, the end result of assembling the HD system with a cascade solar still was studied. The daily productivity of the system increases from 28% to 141% in the presence of humidification–dehumidification system. It also improves the thermal efficiency from 9% to 20% after using 40–150 ml/min of flow rate, respectively. The maximum productivity and efficiency were 5.4 kg/m"2 day and 39% for minimum flow rate.

Perception of cabin air quality in airline crew related to air humidification, on intercontinental flights.

Science.gov (United States)

Lindgren, T; Norbäck, D; Wieslander, G

2007-06-01

The influence of air humidification in aircraft, on perception of cabin air quality among airline crew (N = 71) was investigated. In-flight investigations were performed in the forward part and in the aft part on eight intercontinental flights with one Boeing 767 individually, equipped with an evaporation humidifier combined with a dehumidifying unit, to reduce accumulation of condensed water in the wall construction. Four flights had the air humidification active when going out, and turned off on the return flight. The four others had the inverse humidification sequence. The sequences were randomized, and double blind. Air humidification increased relative air humidity (RH) by 10% in forward part, and by 3% in aft part of the cabin and in the cockpit. When the humidification device was active, the cabin air was perceived as being less dry (P = 0.008), and fresher (P = 0.002). The mean concentration of viable bacteria (77-108 cfu/m(3)), viable molds (74-84 cfu/m(3)), and respirable particles (1-8 microg/m3) was low, both during humidified and non-humidified flights. On flights with air humidification, there were less particles in the forward part of the aircraft (P = 0.01). In conclusion, RH can be slightly increased by using ceramic evaporation humidifier, without any measurable increase of microorganisms in cabin air. The cabin air quality was perceived as being better with air humidification. PRACTICAL IMPLICATION: Relative air humidity is low (10-20%) during intercontinental flights, and can be increased by using ceramic evaporation humidifier, without any measurable increase of microorganism in cabin air. Air humidification could increase the sensation of better cabin air quality.

The clinical utility of long-term humidification therapy in chronic airway disease.

Science.gov (United States)

Rea, Harold; McAuley, Sue; Jayaram, Lata; Garrett, Jeffrey; Hockey, Hans; Storey, Louanne; O'Donnell, Glenis; Haru, Lynne; Payton, Matthew; O'Donnell, Kevin

2010-04-01

Persistent airway inflammation with mucus retention in patients with chronic airway disorders such as COPD and bronchiectasis may lead to frequent exacerbations, reduced lung function and poor quality of life. This study investigates if long-term humidification therapy with high flow fully humidified air at 37 degrees C through nasal cannulae can improve these clinical outcomes in this group of patients. 108 patients diagnosed with COPD or bronchiectasis were randomised to daily humidification therapy or usual care for 12 months over which exacerbations were recorded. Lung function, quality of life, exercise capacity, and measures of airway inflammation were also recorded at baseline, 3 and 12 months. Patients on long-term humidification therapy had significantly fewer exacerbation days (18.2 versus 33.5 days; p = 0.045), increased time to first exacerbation (median 52 versus 27 days; p = 0.0495) and reduced exacerbation frequency (2.97/patient/year versus 3.63/patient/year; p = 0.067) compared with usual care. Quality of life scores and lung function improved significantly with humidification therapy compared with usual care at 3 and 12 months. Long-term humidification therapy significantly reduced exacerbation days, increased time to first exacerbation, improved lung function and quality of life in patients with COPD and bronchiectasis. Clinical trial registered with www.actr.org.au; Number ACTRN2605000623695. Copyright 2010 Elsevier Ltd. All rights reserved.

[Effect of airway humidification on lung injury induced by mechanical ventilation].

Science.gov (United States)

Song, Junjie; Jiang, Min; Qi, Guiyan; Xie, Yuying; Wang, Huaiquan; Tian, Yonggang; Qu, Jingdong; Zhang, Xiaoming; Li, Haibo

2014-12-01

To explore the effect of airway humidification on lung injury as a result of mechanical ventilation with different tidal volume (VT). Twenty-four male Japanese white rabbits were randomly divided into four groups: low VT with airway humidification group, high VT with airway humidification group, low VT and high VT group without humidification, with 6 rabbits in each group. Mechanical ventilation was started after intubation and lasted for 6 hours. Low VT denoted 8 mL/kg, while high VT was 16 mL/kg, fraction of inspired oxygen (FiO₂) denoted 0.40, positive end-expiratory pressure (PEEP) was 0. Temperature at Y piece of circuit in airway humidification groups was monitored and controlled at 40 centigrade. Arterial blood gas analysis, including pH value, arterial partial pressure of oxygen (PaO₂), arterial partial pressure of carbon dioxide (PaCO₂), lung mechanics indexes, including peak airway pressure (P(peak)) and airway resistance (Raw), and lung compliance was measured at 0, 2, 4, 6 hours of mechanical ventilation. The levels of tumor necrosis factor-α (TNF-α) and interleukin-8 (IL-8) in plasma and bronchoalveolar lavage fluid (BALF) were determined by enzyme linked immunosorbent assay (ELISA). The animals were sacrificed at the end of mechanical ventilation. The wet to dry (W/D) ratio of lung tissues was calculated. Histopathologic changes in the lung tissueies were observed with microscope, and lung injury score was calculated. Scanning and transmission electron microscopies were used to examine the integrity of the airway cilia and the tracheal epithelium. Compared with low V(T) group, pH value in high V(T) group was significantly increased, PaCO₂was significantly lowered, and no difference in PaO₂was found. P(peak), Raw, and lung compliance were significantly increased during mechanical ventilation. There were no significant differences in blood gas analysis and lung mechanics indexes between low V(T) with airway humidification group and low V

Humidification of inspired oxygen is increased with pre-nasal cannula, compared to intranasal cannula.

Science.gov (United States)

Dellweg, Dominic; Wenze, Markus; Hoehn, Ekkehard; Bourgund, Olaf; Haidl, Peter

2013-08-01

Oxygen therapy is usually combined with a humidification device, to prevent mucosal dryness. Depending on the cannula design, oxygen can be administered pre- or intra-nasally (administration of oxygen in front of the nasal ostia vs cannula system inside the nasal vestibulum). The impact of cannula design on intra-nasal humidity, however, has not been investigated to date. First, to develop a system, that samples air from the nasal cavity and analyzes the humidity of these samples. Second, to investigate nasal humidity during pre-nasal and intra-nasal oxygen application, with and without humidification. We first developed and validated a sampling and analysis system to measure humidity from air samples. By means of this system we measured inspiratory air samples from 12 subjects who received nasal oxygen with an intra-nasal and pre-nasal cannula at different flows, with and without humidification. The sampling and analysis system showed good correlation to a standard hygrometer within the tested humidity range (r = 0.99, P humidification (P = .001, P humidification. With the addition of humidification we observed no significant change in humidity at any flow, and independent of pre- or intranasal oxygen administration. Pre-nasal administration of dry oxygen achieves levels of intranasal humidity similar to those achieved by intranasal administration in combination with a bubble through humidifier. Pre-nasal oxygen simplifies application and may reduce therapy cost.

Adsorption Desalination: A Novel Method

KAUST Repository

Ng, Kim Choon

2010-11-15

The search for potable water for quenching global thirst remains a pressing concern throughout many regions of the world. The demand for new and sustainable sources and the associated technologies for producing fresh water are intrinsically linked to the solving of potable water availability and hitherto, innovative and energy efficient desalination methods seems to be the practical solutions. Quenching global thirst by adsorption desalination is a practical and inexpensive method of desalinating the saline and brackish water to produce fresh water for agriculture irrigation, industrial, and building applications. This chapter provides a general overview of the adsorption fundamentals in terms of adsorption isotherms, kinetics, and heat of adsorption. It is then being more focused on the principles of thermally driven adsorption desalination methods. The recent developments of adsorption desalination plants and the effect of operating conditions on the system performance in terms of specific daily water production and performance ratio are presented. Design of a large commercial adsorption desalination plant is also discussed herein.

Exergy Evaluation of Desalination Processes

Directory of Open Access Journals (Sweden)

Veera Gnaneswar Gude

2018-06-01

Full Text Available Desalination of sea or brackish water sources to provide clean water supplies has now become a feasible option around the world. Escalating global populations have caused the surge of desalination applications. Desalination processes are energy intensive which results in a significant energy portfolio and associated environmental pollution for many communities. Both electrical and heat energy required for desalination processes have been reduced significantly over the recent years. However, the energy demands are still high and are expected to grow sharply with increasing population. Desalination technologies utilize various forms of energy to produce freshwater. While the process efficiency can be reported by the first law of thermodynamic analysis, this is not a true measure of the process performance as it does not account for all losses of energy. Accordingly, the second law of thermodynamics has been more useful to evaluate the performance of desalination systems. The second law of thermodynamics (exergy analysis accounts for the available forms of energy in the process streams and energy sources with a reference environment and identifies the major losses of exergy destruction. This aids in developing efficient desalination processes by eliminating the hidden losses. This paper elaborates on exergy analysis of desalination processes to evaluate the thermodynamic efficiency of major components and process streams and identifies suitable operating conditions to minimize exergy destruction. Well-established MSF, MED, MED-TVC, RO, solar distillation, and membrane distillation technologies were discussed with case studies to illustrate the exergy performances.

Numerical simulation of humidification and heating during inspiration within an adult nose.

Science.gov (United States)

Sommer, F; Kroger, R; Lindemann, J

2012-06-01

The temperature of inhaled air is highly relevant for the humidification process. Narrow anatomical conditions limit possibilities for in vivo measurements. Numerical simulations offer a great potential to examine the function of the human nose. In the present study, the nasal humidification of inhaled air was simulated simultaneously with temperature distribution during a respiratory cycle. A realistic nose model based on a multislice CT scan was created. The simulation was performed by the Software Fluent(r). Boundary conditions were based on previous in vivo measurements. Inhaled air had a temperature of 20(deg)C and relative humidity of 30%. The wall temperature was assumed to be variable from 34(deg)C to 30(deg)C with constant humidity saturation of 100% during the respiratory cycle. A substantial increase in temperature and humidity can be observed after passing the nasal valve area. Areas with high speed air flow, e.g. the space around the turbinates, show an intensive humidification and heating potential. Inspired air reaches 95% humidity and 28(deg)C within the nasopharynx. The human nose features an enormous humidification and heating capability. Warming and humidification are dependent on each other and show a similar spacial pattern. Concerning the climatisation function, the middle turbinate is of high importance. In contrast to in vivo measurements, numerical simulations can explore the impact of airflow distribution on nasal air conditioning. They are an effective method to investigate nasal pathologies and impacts of surgical procedures.

Environmental impact assessment of nuclear desalination

International Nuclear Information System (INIS)

2010-03-01

Nuclear desalination is gaining interest among the IAEA Member States, as indicated by the planned projects, and it is expected that the number of nuclear desalination plants will increase in the near future. The IAEA has already provided its Member States with reports and documents that disseminate information regarding the technical and economic feasibility of nuclear desalination. With the rising environmental awareness, in the scope of IAEA's activities on seawater desalination using nuclear power, a need was identified for a report that would provide a generic assessment of the environmental issues in nuclear desalination. In order to offer an overview of specific environmental impacts which are to be expected, their probable magnitude, and recommended mitigation measures, this publication encompasses information provided by the IAEA Member States as well as other specialized sources. It is intended for decision makers and experts dealing with environmental, desalination and water management issues, offering insight into the environmental aspects that are essential in planning and developing nuclear desalination

IAEA's role in nuclear desalination

International Nuclear Information System (INIS)

Khamis, I.; )

2010-01-01

Currently, several Member States have shown interest in the utilization of the nuclear energy for seawater desalination not only because recent studies have demonstrated that nuclear desalination is feasible, but also economical and has been already demonstrated in several countries. Therefore, the article will provide a highlight on sea water desalination using nuclear energy as a potential for a sustainable development around the world and the IAEA role in this regards. Special emphasis is placed on past, present, and future nuclear desalination experience in various IAEA Member States. The International Atomic Energy Agency (IAEA) role could be summarized in facilitating cutting-edge developments in the area of seawater desalination using nuclear energy, and establishing a framework for facilitating activities in Member States through information exchange and provision of technical assistance. (author)

Microfluidic desalination techniques and their potential applications

NARCIS (Netherlands)

Roelofs, Susan Helena; van den Berg, Albert; Odijk, Mathieu

2015-01-01

In this review we discuss recent developments in the emerging research field of miniaturized desalination. Traditionally desalination is performed to convert salt water into potable water and research is focused on improving performance of large-scale desalination plants. Microfluidic desalination

International Conference on water reuse and desalination

International Nuclear Information System (INIS)

1984-01-01

The International conference on water reuse and desalination was held on the 13 November 1984 in Johannesburg, South Africa. Papers delivered on this conference covered the following aspects: desalination technology, industrial effluent control, economics of desalination of wastewaters, consumable supplies in desalination, the world market for seawater desalination equipment, reverse osmosis, evaporation and ultrafiltration, treatment of hazardous wastes, role of reverse osmosis in waste water treatment, as well as the desalination, recovery and recycle of water with high efficiency. A paper was also delivered on the mechanical vapour compression process applied to seawater desalination - as an example the paper presents the largest unit so far constructed by SIDEM using this process: a 1,500 mz/day unit installed in the Nuclear power plant of Flamanville in France

[Humidification assessment of four heat and moisture exchanger filters according to ISO 9360: 2000 standard].

Science.gov (United States)

Lannoy, D; Décaudin, B; Resibois, J-P; Barrier, F; Wierre, L; Horrent, S; Batt, C; Moulront, S; Odou, P

2008-02-01

This work consisted of the assessment of humidification parameters and flow resistance for different heat and moisture exchanger filters (HMEF) used in intensive care unit. Four electrostatic HMEF were assessed: Hygrobac S (Tyco); Humidvent compact S (Teleflex); Hygrovent S/HME (Medisize-Dräger); Clear-Therm+HMEF (Intersurgical). Humidification parameters (loss of water weight, average absolute moisture [AAM], absolute variation of moisture) have been evaluated on a bench-test in conformity with the ISO 9360: 2000 standard, for 24h with the following ventilatory settings: tidal volume at 500 ml, respiratory rate at 15 c/min, and inspiration/expiration ratio at 1:1. The flow resistance of HMEFs assessed using the pressure drop method was measured before and after 24h of humidification for three increasing air flows of 30, 60, and 90 l/min. All the HMEFs allowed satisfactory level of humidification exceeding 30 mgH(2)O/l. The less powerful remained the Clear-Therm. Concerning HMEFs flow resistance, results showed a pressure drop slightly more important for the Hygrobac S filter as compared with other filters. This test showed differences between the HMEFs for both humidification and resistance parameters. When compared to the new version of the standards, HMEFs demonstrated their reliability. However, evolution of humidification and flow resistance characteristics over 24h showed a structural degradation of HMEFs, limiting their use over a longer period.

ENERGY EFFICIENT DESALINATOR

Directory of Open Access Journals (Sweden)

T. A. Ismailov

2017-01-01

Full Text Available Objectives. The aim of the research is to develop a thin-film semiconductor thermoelectric heat pump of cylindrical shape for the desalination of sea water.Methods. To improve the efficiency of the desalination device, a  special thin-film semiconductor thermoelectric heat pump of  cylindrical shape is developed. The construction of the thin-film  semiconductor thermoelectric heat pump allows the flow rates of  incoming sea water and outflowing fresh water and brine to be  equalised by changing the geometric dimensions of the desalinator.  The cross-sectional area of the pipeline for incoming sea water is equal to the total area of outflowing fresh water and brine.Results. The use of thin-film semiconductor p- and n-type branches  in a thermo-module reduces their electrical resistance virtually to  zero and completely eliminates Joule's parasitic heat release. The  Peltier thermoelectric effect on heating and cooling is completely  preserved, bringing the efficiency of the heat pump to almost 100%, improving the energy-saving characteristics of the  desalinator as a whole. To further increase the efficiency of the  proposed desalinator, thermoelectric modules with radiation can be  used as thermoelectric devices.Conclusion. As a consequence of the creation of conditions of high rarefaction under which water will be converted to steam, which, at  20° C, is cold (as is the condensed distilled water, energy costs can  be reduced. In this case, the energy for heating and cooling is not  wasted; moreover, sterilisation is also achieved using the ultraviolet  radiation used in the thermoelectric devices, which, on the one hand, generate electromagnetic ultraviolet radiation, and, on the other, cooling. Such devices operate in optimal mode without heat  release. The desalination device can be used to produce fresh water and concentrated solutions from any aqueous solutions, including wastewater from industrial

Commercial high efficiency dehumidification systems using heat pipes

Energy Technology Data Exchange (ETDEWEB)

1993-09-01

An improved heat pipe design using separately connected two-section one-way flow heat pipes with internal microgrooves instead of wicks is described. This design is now commercially available for use to increase the dehumidification capacity of air conditioning systems. The design also includes a method of introducing fresh air into buildings while recovering heat and controlling the humidity of the incoming air. Included are applications and case studies, load calculations and technical data, and installation, operation, and maintenance information.

A comparative study of compression-expansion type dehumidification systems to achieve low dew point air

International Nuclear Information System (INIS)

Moon, Choon; Bansal, Pradeep

2009-01-01

This paper presents a theoretical feasibility study of three dehumidification systems to achieve air with dew points down to (-) 40 deg. C. The systems consist of compressors, heat exchangers, expanders and heaters. A thermodynamic model has been developed of the systems to study the effect of the compressor, expander, and heat recovery heat exchanger efficiency as a function of pressure ratio, net required work, quantity of condensed moisture, and system outlet dew point temperature. The analysis has revealed that the selection of a heat recovery heat exchanger is critical for an efficient dehumidification system, where compressor efficiency has the dominant effect on power consumption.

Desalination of Seawater using Nuclear Energy

International Nuclear Information System (INIS)

Misra, B.M.

2006-01-01

Desalination technologies have been well established since the mid 20th century and are widely deployed in many parts of the world having acute water scarcity problems. The energy for these plants is generally supplied in the form of either steam or electricity largely using fossil fuels. The intensive fuels of fossil fuels raises environmental concerns especially in relation to greenhouse gas emissions. The depleting sources and future price uncertainty of the fossil fuels and their better use for other vital industrial applications is also a factor to be considered for sustainability. The desalination of sea water using nuclear energy is a feasible option to meet the growing demand of potable water. Over 150 reactor-years of operating experience of a nuclear desalination have been accumulated worldwide. Several demonstration programs of nuclear desalination are also in progress to confirm its technical and economic viability under country specific conditions, with the technical coordination or support of IAEA. Recent techno-economic feasibility studies carried out by some Member States indicate the competitiveness of nuclear desalination. This paper presents the salient activities on nuclear desalination in the Agency and in the interested Member states. Economic research on further water cost reduction includes investigation on utilization of waste heat from different reactor types for thermal desalination pre-heat reverse osmosis and hybrid desalination systems. The main challenge for the large scale deployment of nuclear seawater desalination is the lack of infrastructure and the resources in the countries affected by water scarcity problems which are however, interested in adoption of nuclear desalination for the sustainable water resources. Socio-economic and environmental aspects and the public perception are also important factors requiring greater information exchange. (author)

Humidification and perceived indoor air quality in the office environment.

Science.gov (United States)

Reinikainen, L M; Aunela-Tapola, L; Jaakkola, J J

1997-01-01

OBJECTIVE: To evaluate the effect of humidification on the odour, acceptability, and stuffiness of indoor air. METHODS: In a six period cross over trial at the Pasila Office Center, Helsinki, the air of two wings of the building in turn were ventilated with air of 30%-40% humidity. A third wing served as a non-humidified control area. The quality of indoor air was assessed weekly by a panel containing 18 to 23 members. The intraindividual differences in the ratings for odour, stuffiness, and acceptability between humidified and non-humidified wings were used to assess the effect of humidification. The roles of sex, current smoking, and age as potential effect modifiers were assessed by comparing the mean intraindividual differences in ratings between the groups. RESULTS: Humidified air was found to be more odorous and stuffy (paired t test P = 0.0001) and less acceptable than the non-humidified air (McNemar's test P humidification decreases the perceived air quality. This effect is strongest in women and young subjects. PMID:9196454

Experimental analysis of humidification process by air passing through seawater

International Nuclear Information System (INIS)

El-Agouz, S.A.; Abugderah, M.

2008-01-01

An experimental investigation of humidification process by air passing through seawater is presented. The main objective of this work was to determine the humid air behaviour through single-stage of heating-humidifying processes. This experimental work studied the influence of the operating conditions such as the water temperature, the headwater difference, the air velocity and the inlet air temperature to evaporator chamber on the vapour content difference and humidification efficiency. Two cases of different inlet conditions of ambient and heated air cases are studied. The experimental results show that, the vapour content difference and the humidification efficiency of the system is strongly affected by the saline water temperature in the evaporator chamber, headwater difference and the air velocity. The inlet air temperature to evaporator chamber variation was found to have a small affect on the vapour content difference. The obtained maximum vapour content difference of the air was about 222 gr w /kg a at 75 deg. C for water and air. The obtained vapour content is high compared to that obtained in literature for single-stage and very similar for multi-stage

Nuclear Desalination Newsletter, No. 2, September 2010

International Nuclear Information System (INIS)

2010-09-01

Seawater desalination is increasingly becoming a vital option for alleviating severe water shortages around the world, and especially in developing countries. Worldwide seawater desalination capacity is expected to increase beyond the current contracted estimate of about 60 million m3/d. The need for an adequate supply of potable water for growing populations and complex problems is now globally recognized. Desalination using nuclear energy could play a vital role in supplying the much needed potable water for sustainable development and alleviate some of the environment impact of using fossil fuels for desalination. The IAEA programme on nuclear desalination continues to provide support to Member States through various forums of information exchange, technical cooperation projects, and publications. In the last year, the IAEA launched a new coordinated research programme which aims at investigating new technologies for seawater desalination using nuclear energy; updated and released a new version of the IAEA DEEP software; released a newly developed toolkit on nuclear desalination; and organized (jointly with the International Centre for Theoretical Physics ICTP) a training workshop on Technology and Performance of Desalination Systems

Humidification of unwrapped chilled meat on retail display using an ultrasonic fogging system.

Science.gov (United States)

Brown, Tim; Corry, Janet E L; Evans, Judith A

2007-12-01

The effects of an ultrasonic humidification system on unwrapped meat in a chilled retail display cabinet were assessed. Humidification raised the relative humidity of the cabinet air from a mean of 76.7% to just below saturation at 98.8%. This reduced the mean evaporative weight loss from whole samples of meat after 14h from 1.68% to 0.62% of their initial weight. The rate of deterioration in the appearance of the meat due to dehydration was reduced to the extent that while the unhumidified trial was terminated after 14h because all samples were judged to be unacceptable, the humidified trial was continued for 24h without any major changes in appearance. Levels of presumptive pseudomonas bacteria were relatively high in water samples taken from the humidification system and defrost water during the humidified trial, but Legionella spp. were not isolated. Significant increases in the numbers of bacteria on the meat during either trial were only found in one case, that of humidified minced beef. However, some of the samples had high counts even before display, and this may have masked any effect due to humidification. Differences in levels of air-borne contamination were small and inconsistent. Air temperatures were raised by humidification by between 1 and 2°C and this was reflected in similarly raised product temperatures. Temperatures of air leaving the evaporator indicated that this was due to icing of the evaporator in the periods leading up to defrosts.

Design and control of the oxygen partial pressure of UO2 in TGA using the humidification system

International Nuclear Information System (INIS)

Lee, S.; Knight, T.W.; Roberts, E.

2015-01-01

Highlights: • We focus on measurement of oxygen partial pressure and change of O/M ratio under specific conditions produced by the humidification system. • This shows that the humidification system is stable, accurate, and reliable enough to be used for experiments of the oxygen partial pressure measurement for the oxide fuels. • The humidification system has benefits of easy control and flexibility for producing various oxygen partial pressures with fixed hydrogen gas flow rate. - Abstract: The oxygen to uranium (O/U) ratio of UO 2±x is determined by the oxygen content of the sample and is affected by oxygen partial pressure (pO 2 ) of the surrounding gas. Oxygen partial pressure is controllable by several methods. A common method to produce different oxygen partial pressures is the use of equilibria of different reaction gases. There are two common methods: H 2 O/H 2 reaction and CO 2 /CO reaction. In this work, H 2 O/H 2 reaction using a humidifier was employed and investigated to ensure that this humidification system for oxygen partial pressure is stable and accurate for use in Thermogravimetric Analyzer (TGA) experiments with UO 2 . This approach has the further advantage of flexibility to make a wide range of oxygen partial pressure with fixed hydrogen gas flow rate only by varying temperature of water in the humidifier. The whole system for experiments was constructed and includes the humidification system, TGA, oxygen analyzer, and gas flow controller. Uranium dioxide (UO 2 ) samples were used for experiments and oxygen partial pressure was measured at the equilibrium state of stoichiometric UO 2.0 . Oxygen partial pressures produced by humidification (wet gas) system were compared to the approach using mixed dry gases (without humidification system) to demonstrate that the humidification system provides for more stable and accurate oxygen partial pressure control. This work provides the design, method, and analysis of a humidification system for

Nuclear Desalination Newsletter, No. 3, September 2011

International Nuclear Information System (INIS)

2011-09-01

The continuing improvement of technologies and decrease of cost, seawater desalination is expected to play an important role in the global economic and social development as well as in the ecological environment, especially for regions having severe water shortages such as China and the Middle East. Seawater desalination using nuclear energy is not only technically feasible but economically an option in varying site conditions and with a variety of nuclear reactor concepts. In any given country, nuclear desalination will become a viable option if the following two prerequisites exist: lack of potable water and the ability to deploy nuclear energy. In most regions, only one of the two is fulfilled. Many countries; e.g. China, the Republic of Korea and, even more so, India and Pakistan have both factors present. These countries already account for almost half the world's population, and thus represent a potential long term market for nuclear desalination. The accumulated experience in nuclear desalination will undoubtedly contribute to what many consider as the world wide central issue of the 21st century: the crucial need for new sources of freshwater for sustainable development. Within its continuing efforts to support Member States through various forums of information exchange, technical cooperation projects, and publications, the IAEA updated and released a new version of Desalination Economic Evaluation Program (DEEP 4.0) in 2011 with new features and easier usability for both newcomers and experts. The IAEA also released a new tool named DEsalination Thermodynamic Optimization Program (DE-TOP), which complements DEEP and is used to analyze the thermodynamics of cogeneration systems with emphasis on water desalination. The IAEA toolkit on nuclear desalination, intended for Member States considering nuclear power for seawater desalination, provides access to information on nuclear desalination including DEEP and DE-TOP. This tool was further improved in 2010

The effect of mouth leak and humidification during nasal non-invasive ventilation.

Science.gov (United States)

Tuggey, Justin M; Delmastro, Monica; Elliott, Mark W

2007-09-01

Poor mask fit and mouth leak are associated with nasal symptoms and poor sleep quality in patients receiving domiciliary non-invasive ventilation (NIV) through a nasal mask. Normal subjects receiving continuous positive airways pressure demonstrate increased nasal resistance following periods of mouth leak. This study explores the effect of mouth leak during pressure-targeted nasal NIV, and whether this results in increased nasal resistance and consequently a reduction in effective ventilatory support. A randomised crossover study of 16 normal subjects was performed on separate days. Comparison was made of the effect of 5 min of mouth leak during daytime nasal NIV with and without heated humidification. Expired tidal volume (V(T)), nasal resistance (R(N)), and patient comfort were measured. Mean change (Delta) in V(T) and R(N) were significantly less following mouth leak with heated humidification compared to the without (DeltaV(T) -36+/-65 ml vs. -88+/-50 ml, phumidification (5.3+/-0.4 vs. 6.2+/-0.4, phumidification. In normal subjects, heated humidification during nasal NIV attenuates the adverse effects of mouth leak on effective tidal volume, nasal resistance and improves overall comfort. Heated humidification should be considered as part of an approach to patients who are troubled with nasal symptoms, once leak has been minimised.

Using EnergyPlus to Perform Dehumidification Analysis on Building America Homes

Energy Technology Data Exchange (ETDEWEB)

Fang, Xia [National Renewable Energy Lab. (NREL), Golden, CO (United States); Winkler, Jon [National Renewable Energy Lab. (NREL), Golden, CO (United States); Christensen, Dane [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2011-03-01

This study used EnergyPlus to investigate humidity issues on a typical mid-1990s reference home, a 2006 International Energy Conservation Code home, and a high-performance home in a hot-humid climate; the study confirmed that supplemental dehumidification should be provided to maintain space relative humidity below 60% in a hot-humid climate.

Field Study on Humidification Performance of a Desiccant Air-Conditioning System Combined with a Heat Pump

Directory of Open Access Journals (Sweden)

Koichi Kawamoto

2016-01-01

Full Text Available A desiccant air-conditioning system was developed as a latent-load-processing air conditioner in a dedicated outdoor air system during the summer. This study investigated the application of this air-conditioning system to humidification during the winter without using make-up water, thereby eliminating the cause of microbial contamination in air-conditioning systems. The experiments were conducted with a system used for summer applications to determine the feasibility of adsorbing vapor from outdoor air and supplying it to an indoor space. The humidification performance, energy efficiency, and operating conditions were examined. Although the conditions were subpar because the experiments were performed with an actual dedicated outdoor air system, the results showed that it is possible to supply air with a minimum humidity ratio of 5.8 g/kg dry air (DA when the humidity ratio of outdoor air ranges from 1.8 to 2.3 g/kg DA. The minimum humidification performance required for a dedicated outdoor air system was achieved by increasing the airflow rate of the moisture-adsorption side to 2–3 times that of the humidification side. In addition, air leaking from the moisture-adsorption side to the humidification side, improving the mechanical structure, such as by the insulation of the moisture-adsorption side, and an efficient operating method were examined for humidification during the winter.

Humidification during high-frequency oscillation ventilation is affected by ventilator circuit and ventilatory setting.

Science.gov (United States)

Chikata, Yusuke; Imanaka, Hideaki; Onishi, Yoshiaki; Ueta, Masahiko; Nishimura, Masaji

2009-08-01

High-frequency oscillation ventilation (HFOV) is an accepted ventilatory mode for acute respiratory failure in neonates. As conventional mechanical ventilation, inspiratory gas humidification is essential. However, humidification during HFOV has not been clarified. In this bench study, we evaluated humidification during HFOV in the open circumstance of ICU. Our hypothesis is that humidification during HFOV is affected by circuit design and ventilatory settings. We connected a ventilator with HFOV mode to a neonatal lung model that was placed in an infant incubator set at 37 degrees C. We set a heated humidifier (Fisher & Paykel) to obtain 37 degrees C at the chamber outlet and 40 degrees C at the distal temperature probe. We measured absolute humidity and temperature at the Y-piece using a rapid-response hygrometer. We evaluated two types of ventilator circuit: a circuit with inner heating wire and another with embedded heating element. In addition, we evaluated three lengths of the inspiratory limb, three stroke volumes, three frequencies, and three mean airway pressures. The circuit with embedded heating element provided significantly higher absolute humidity and temperature than one with inner heating wire. As an extended tube lacking a heating wire was shorter, absolute humidity and temperature became higher. In the circuit with inner heating wire, absolute humidity and temperature increased as stroke volume increased. Humidification during HFOV is affected by circuit design and ventilatory settings.

Thermodynamic and numerical analysis of intake air humidification ...

Indian Academy of Sciences (India)

Bin Chen

2018-05-14

May 14, 2018 ... ciency while reducing emissions to meet the market requirements. For gasoline ... and the effects of intake air humidification on knock. In this case, this ..... efficient strategy of suppressing knock occurrence of gasoline engines.

Multi effect desalination and adsorption desalination (MEDAD): A hybrid desalination method

KAUST Repository

Shahzad, Muhammad Wakil; Ng, Kim Choon; Thu, Kyaw; Saha, Bidyut Baran; Chun, Wongee

2014-01-01

This paper presents an advanced desalination cycle that hybridizes a conventional multi-effect distillation (MED) and an emerging yet low-energy adsorption cycle (AD). The hybridization of these cycles, known as MED + AD or MEDAD in short, extends

Economical analysis of a solar desalination system

DEFF Research Database (Denmark)

Chen, Ziqian; Wang, Tie-Zhu; He, Xiao-Rong

2012-01-01

Based on the calculation of the single-factor impact values of the parameters of a triple stage tower-type of solar desalination unit by utilizing a single-factor analyzing method, the influences of the cost of solar heating system, the cost of hot water tank, the costs of desalination unit...... and yearly electrical power, the life time of solar desalination unit and the yearly yield of fresh water, on the cost of the fresh water production of the solar desalination unit are studied. It is helpful to do the further investigation on solar desalination systems for reducing the cost of fresh water...

Design concepts of nuclear desalination plants

International Nuclear Information System (INIS)

2002-11-01

Interest in using nuclear energy for producing potable water has been growing worldwide in the past decade. This has been motivated by a variety of factors, including economic competitiveness of nuclear energy, the growing need for worldwide energy supply diversification, the need to conserve limited supplies of fossil fuels, protecting the environment from greenhouse gas emissions, and potentially advantageous spin-off effects of nuclear technology for industrial development. Various studies, and at least one demonstration project, have been considered by Member States with the aim of assessing the feasibility of using nuclear energy for desalination applications under specific conditions. In order to facilitate information exchange on the subject area, the IAEA has been active for a number of years in compiling related technical publications. In 1999, an inter regional technical co-operation project on Integrated Nuclear Power and desalination System Design was launched to facilitate international collaboration for the joint development by technology holders and potential end users of an integrated nuclear desalination system. This publication presents material on the current status of nuclear desalination activities and preliminary design concepts of nuclear desalination plants, as made available to the IAEA by various Member States. It is aimed at planners, designers and potential end-users in those Member States interested in further assessment of nuclear desalination. Interested readers are also referred to two related and recent IAEA publications, which contain useful information in this area: Introduction of Nuclear Desalination: A Guidebook, Technical Report Series No. 400 (2000) and Safety Aspects of Nuclear Plants Coupled with Seawater Desalination Units, IAEA-TECDOC-1235 (2001)

Mask humidity during CPAP: influence of ambient temperature, heated humidification and heated tubing

Directory of Open Access Journals (Sweden)

Nilius G

2018-05-01

Full Text Available Georg Nilius,1,2 Ulrike Domanski,1 Maik Schroeder,1 Holger Woehrle,3,4 Andrea Graml,4 Karl-Josef Franke,1,2 1Helios Klinik Hagen-Ambrock, Department of Pneumology, Hagen, Germany; 2Department of Internal Medicine, Witten-Herdecke University, Witten, Germany; 3Sleep and Ventilation Center Blaubeuren, Respiratory Center Ulm, Ulm, Germany; 4ResMed Science Center, ResMed Germany, Martinsried, Germany Purpose: Mucosal drying during continuous positive airway pressure (CPAP therapy is problematic for many patients. This study assessed the influence of ambient relative humidity (rH and air temperature (T in winter and summer on mask humidity during CPAP, with and without mask leak, and with or without heated humidification ± heated tubing. Methods: CPAP (8 and 12 cmH2O without humidification (no humidity [nH], with heated humidification controlled by ambient temperature and humidity (heated humidity [HH] and HH plus heated tubing climate line (CL, with and without leakage, were compared in 18 subjects with OSA during summer and winter. Results: The absolute humidity (aH and the T inside the mask during CPAP were significantly lower in winter versus summer under all applied conditions. Overall, absolute humidity differences between summer and winter were statistically significant in both HH and CL vs. nH (p < 0.05 in the presence and absence of mouth leak. There were no significant differences in aH between HH and CL. However, in-mask temperature during CL was higher (p < 0.05 and rH lower than during HH. In winter, CPAP with CL was more likely to keep rH constant at 80% than CPAP without humidification or with standard HH. Conclusion: Clinically-relevant reductions in aH were documented during CPAP given under winter conditions. The addition of heated humidification, using a heated tube to avoid condensation is recommended to increase aH, which could be useful in CPAP users complaining of nose and throat symptoms. Keywords: continuous positive

Thermoeconomic Optimization of a Combined Heating and Humidification Coil for HVAC Systems

Science.gov (United States)

Teodoros, Liliana; Andresen, Bjarne

2016-07-01

The total cost of ownership is calculated for a combined heating and humidification coil of an air-handling unit taking into account investment and operation costs simultaneously. This total cost represents the optimization function for which the minimum is sought. The parameters for the cost dependencies are the physical dimensions of the coil: length, width and height. The term "coil" is used generically since in this setup it generates heating as well as humidification in a single unit. The first part of the paper deals with the constructive optimization and finds the relationship between the dimensions for a minimum cost. The second part of the paper takes the results of the constructive optimization further and, based on the data derived in our previous papers, analyzes the minimum total cost for the humidification coil while balancing the amount of water used to humidify the air and modify its temperature.

Nuclear desalination activities in India

International Nuclear Information System (INIS)

Bhattacharjee, B.

1999-01-01

The main emphasis of this article is on utilization of nuclear energy for desalination. Nuclear desalination is cheaper, eco-friendly and assists in sustainable growth of total energy generation programme in a country. PHWR type reactors are the main stay of nuclear energy programme in India. Nuclear waste heat for desalination is available in the moderator system of the 220 MW(e) and 500 MW(e) PHWRs. The low temperature evaporation technology (LET) for producing pure water from sea water is also discussed

Systematic studies of the gas humidification effects on spatial PEMFC performance distributions

International Nuclear Information System (INIS)

Reshetenko, Tatyana V.; Bender, Guido; Bethune, Keith; Rocheleau, Richard

2012-01-01

Highlights: ► We investigated impacts of gases humidification on a local PEMFC performance. ► The spatial performance and EIS were studied by a segmented cell system. ► The data were analyzed in the terms of voltage losses. ► A reduction in anode/cathode gases humidification decreased a PEMFC performance. ► A decrease of humidification led to non-uniform performances and voltage losses distributions. - Abstract: The overall current density that is measured in a proton exchange membrane fuel cell (PEMFC) represents the average of the local reaction rates. The overall and local PEMFC performances are determined by several primary loss mechanisms, namely activation, ohmic, and mass transfer. Spatial performance and loss variabilities are significant and depend on the cell design and operating conditions. A segmented cell system was used to quantify different loss distributions along the gas channel to understand the effects of gas humidification. A reduction in the reactant stream humidification decreased cell performance and resulted in non-uniform distributions of overpotentials and performance along the flow field. Activation and ohmic overpotentials increased with a relative humidity decrease due to insufficient membrane and catalyst layer hydration. The relative humidity of the cathode had a strong impact on the mass transfer overpotential due to a lower oxygen permeability through the dry Nafion film covering the catalyst surface. The mass transfer loss distribution was non-uniform, and the mass transfer overpotential increased for the outlet segments due to the oxygen consumption at the inlet segments, which reduced the oxygen concentration downstream, and a progressive water accumulation from upstream segments. Electrochemical impedance spectroscopy (EIS) and an equivalent electric circuit (EEC) facilitated the analysis and interpretation of the segmented cell data.

Series Assembly of Microbial Desalination Cells Containing Stacked Electrodialysis Cells for Partial or Complete Seawater Desalination

KAUST Repository

Kim, Younggy

2011-07-01

A microbial desalination cell (MDC) is a new approach for desalinating water based on using the electrical current generated by exoelectrogenic bacteria. Previously developed MDCs have used only one or two desalination chambers with substantial internal resistance, and used low salinity catholytes containing a buffered or acid solution. Here we show that substantially improved MDC performance can be obtained even with a nonbuffered, saline catholyte, by using an electrodialysis stack consisting of 5 pairs of desalting and concentrating cells. When 4 stacked MDCs were used in series (20 total pairs of desalination chambers), the salinity of 0.06 L of synthetic seawater (35 g/L NaCl) was reduced by 44% using 0.12 L of anode solution (2:1). The resistive loss in the electrodialysis stack was negligible due to minimization of the intermembrane distances, and therefore the power densities produced by the MDC were similar to those produced by single chamber microbial fuel cells (MFCs) lacking desalination chambers. The observed current efficiency was 86%, indicating separation of 4.3 pairs of sodium and chloride ions for every electron transferred through the circuit. With two additional stages (total of 3.8 L of anolyte), desalination was increased to 98% salt removal, producing 0.3 L of fresh water (12.6:1). These results demonstrate that stacked MDCs can be used for efficient desalination of seawater while at the same time achieving power densities comparable to those obtained in MFCs. © 2011 American Chemical Society.

Electrode placement during electro-desalination of

DEFF Research Database (Denmark)

Ottosen, Lisbeth M.; Andersson, Lovisa C. H.

2017-01-01

Carved stone sculptures and ornaments can be severely damaged by salt induced decay. Often the irregular surfaces are decomposed, and the artwork is lost. The present paper is an experimental investigation on the possibility for using electro-desalination for treatment of stone with irregular shape....... Electro-desalination experiments were made with different duration to follow the progress. Successful desalination of the whole stone piece was obtained, showing that also parts not being placed directly between the electrodes were desalinated. This is important in case of salt damaged carved stones......, where the most fragile parts thus can be desalinated without physically placing electrodes on them. The Cl removal rate was higher in the areas closest to the electrodes and slowest in the part, which was not placed directly between the electrodes. This is important to incorporate in the monitoring...

Desalination of seawater with nuclear reactors

International Nuclear Information System (INIS)

Nisan, S.; Volpi, L.

2003-01-01

About 40 % of the world population is concerned with water scarcity. This article reviews the different techniques of desalination: distillation (MED and MSF), reverse osmosis (RO), and electrodialysis (ED). The use of nuclear energy rests on several arguments: 1) it is economically efficient compared to fossil energy. 2) nuclear reactors provide heat covering a broad range of temperature, which allows the implementation of all the desalination techniques. 3) the heat normally lost at the heat sink could be used for desalination. And 4) nuclear is respectful of the environment. The feedback experience concerning nuclear desalination is estimated to about 100 reactor-years, it is sufficient to allow the understanding of all the physical and technological processes involved. In Japan, 8 PWR-type reactors are coupled to MED, MSF, and RO desalination techniques, the water produced is used locally mainly for feeding steam generators. (A.C.)

Desalination of seawater with nuclear reactors

International Nuclear Information System (INIS)

Nisan, S.; Volpi, L.

2001-01-01

About 40 % of the world population is concerned with water scarcity. This article reviews the different techniques of desalination: distillation (MED and MSF), reverse osmosis (RO), and electrodialysis (ED). The use of nuclear energy rests on several arguments: 1) it is economically efficient compared to fossil energy; 2) nuclear reactors provide heat covering a broad range of temperature, which allows the implementation of all the desalination techniques; 3) the heat normally lost at the heat sink could be used for desalination; and 4) nuclear is respectful of the environment. The feedback experience concerning nuclear desalination is estimated to about 100 reactor-years, it is sufficient to allow the understanding of all the physical and technological processes involved. In Japan, 8 PWR-type reactors are coupled to MED, MSF, and RO desalination techniques, the water produced is used locally mainly for feeding steam generators. (A.C.)

Nuclear energy and water desalination

International Nuclear Information System (INIS)

Leprince-Ringuet, L.

1976-01-01

A short state-of-the-art survey is given of desalination methods, the involvement of nuclear power reactors in some desalination process, the cost of certain methods, and quantities produced and required in different parts of the world

Effect of Heated Humidification on CPAP Therapy Adherence in Subjects With Obstructive Sleep Apnea With Nasopharyngeal Symptoms.

Science.gov (United States)

Soudorn, Chuleekorn; Muntham, Dittapol; Reutrakul, Sirimon; Chirakalwasan, Naricha

2016-09-01

The addition of heated humidification to CPAP has been shown to improve nasal adverse effects in subjects with obstructive sleep apnea (OSA). However, current data regarding improvement in CPAP adherence is conflicting. Furthermore, there are no data from a tropical climate area with a high humidity level. In this prospective randomized crossover study conducted in Thailand, subjects with moderate to severe OSA with nasopharyngeal symptoms post-split-night study were enrolled in the study. Subjects were randomly assigned to receive CPAP with or without heated humidification for 4 weeks and then crossed over. Information on CPAP adherence, quality of life assessed by the Functional Outcomes of Sleep Questionnaire, nasopharyngeal symptoms assessed by a modified XERO questionnaire, and bedroom ambient humidity and temperature data were obtained. Data were collected on 20 subjects with OSA during the period of January to December 2014. Although the addition of heated humidification appeared to improve average hours of use for all days when compared with conventional CPAP, the difference was not statistically significant (CPAP with heated humidification = 4.6 ± 1.7 h/night; conventional CPAP = 4.0 ± 1.7 h/night, P = .1). However, the addition of heated humidification improved CPAP adherence on the days of use (5.5 ± 1.5 h/night) compared with conventional CPAP (5.2 ± 1.4 h/night), P = .033. Quality of life was also improved according to the Functional Outcomes of Sleep Questionnaire score (median 17.6 [interquartile range 3.5]) in the heated humidification group compared with conventional CPAP group (median 17.6 [interquartile range 4.5]), P = .046. Significant reduction in the dry throat/sore throat symptom was noted only when CPAP with heated humidification was used. Even in a tropical climate area, CPAP adherence and quality of life appeared to improve when heated humidification was employed in subjects with moderate to severe OSA with nasopharyngeal symptoms

Design and development of solar desalination plant

Directory of Open Access Journals (Sweden)

Marimuthu Thaneissha a/p

2017-01-01

Full Text Available Direct sunlight has been utilized long back for desalination of water. The desalination process takes place in solar still. Solar still is a device that converts saline water to potable water. This process requires seawater and sunlight which are widely available on Earth. However, the current solar desalination generation capacity is generally low and has high installation cost. Hence, there is a need for the enhancement of the productivity which can be achieved through few modifications. This paper explores the challenges and opportunities of solar water desalination worldwide. It presents a comprehensive review of solar desalination technologies that have been developed in recent years which covers the economic and environmental aspects.

Nanostructured materials for water desalination

Energy Technology Data Exchange (ETDEWEB)

Humplik, T; Lee, J; O' Hern, S C; Fellman, B A; Karnik, R; Wang, E N [Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge (United States); Baig, M A; Hassan, S F; Atieh, M A; Rahman, F; Laoui, T, E-mail: tlaoui@kfupm.edu.sa, E-mail: karnik@mit.edu, E-mail: enwang@mit.edu [Departments of Mechanical Engineering and Chemical Engineering and Research Institute, King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia)

2011-07-22

Desalination of seawater and brackish water is becoming an increasingly important means to address the scarcity of fresh water resources in the world. Decreasing the energy requirements and infrastructure costs of existing desalination technologies remains a challenge. By enabling the manipulation of matter and control of transport at nanometer length scales, the emergence of nanotechnology offers new opportunities to advance water desalination technologies. This review focuses on nanostructured materials that are directly involved in the separation of water from salt as opposed to mitigating issues such as fouling. We discuss separation mechanisms and novel transport phenomena in materials including zeolites, carbon nanotubes, and graphene with potential applications to reverse osmosis, capacitive deionization, and multi-stage flash, among others. Such nanostructured materials can potentially enable the development of next-generation desalination systems with increased efficiency and capacity. (topical review)

Nanostructured materials for water desalination

International Nuclear Information System (INIS)

Humplik, T; Lee, J; O'Hern, S C; Fellman, B A; Karnik, R; Wang, E N; Baig, M A; Hassan, S F; Atieh, M A; Rahman, F; Laoui, T

2011-01-01

Desalination of seawater and brackish water is becoming an increasingly important means to address the scarcity of fresh water resources in the world. Decreasing the energy requirements and infrastructure costs of existing desalination technologies remains a challenge. By enabling the manipulation of matter and control of transport at nanometer length scales, the emergence of nanotechnology offers new opportunities to advance water desalination technologies. This review focuses on nanostructured materials that are directly involved in the separation of water from salt as opposed to mitigating issues such as fouling. We discuss separation mechanisms and novel transport phenomena in materials including zeolites, carbon nanotubes, and graphene with potential applications to reverse osmosis, capacitive deionization, and multi-stage flash, among others. Such nanostructured materials can potentially enable the development of next-generation desalination systems with increased efficiency and capacity. (topical review)

Nanostructured materials for water desalination

Science.gov (United States)

Humplik, T.; Lee, J.; O'Hern, S. C.; Fellman, B. A.; Baig, M. A.; Hassan, S. F.; Atieh, M. A.; Rahman, F.; Laoui, T.; Karnik, R.; Wang, E. N.

2011-07-01

Desalination of seawater and brackish water is becoming an increasingly important means to address the scarcity of fresh water resources in the world. Decreasing the energy requirements and infrastructure costs of existing desalination technologies remains a challenge. By enabling the manipulation of matter and control of transport at nanometer length scales, the emergence of nanotechnology offers new opportunities to advance water desalination technologies. This review focuses on nanostructured materials that are directly involved in the separation of water from salt as opposed to mitigating issues such as fouling. We discuss separation mechanisms and novel transport phenomena in materials including zeolites, carbon nanotubes, and graphene with potential applications to reverse osmosis, capacitive deionization, and multi-stage flash, among others. Such nanostructured materials can potentially enable the development of next-generation desalination systems with increased efficiency and capacity.

Evaluation of the Performance of Houses With and Without Supplemental Dehumidification in a Hot-Humid Climate

Energy Technology Data Exchange (ETDEWEB)

Kerrigan, P. [Building Science Corporation, Westford, MA (United States)

2014-10-01

This report describes a research study that was conducted by the Building Science Corporation (BSC) Building America Research Team. BSC seeks to research and report on the field monitoring of the performance of in-situ supplemental dehumidification systems in low energy, high performance homes in a hot-humid climate. The purpose of this research project was to observe and compare the humidity control performance. Specifically, the study sought to compare the interior conditions and mechanical systems operation between two distinct groups of houses; homes with a supplemental dehumidifier installed in addition to HVAC system, and homes without any supplemental dehumidification. The subjects of the study were 10 single-family, new construction homes in New Orleans, LA.

Energy performance of an innovative liquid desiccant dehumidification system with a counter-flow heat and mass exchanger using potassium formate

DEFF Research Database (Denmark)

Jradi, Muhyiddine; Riffat, Saffa

2014-01-01

An innovative micro-scale liquid desiccant dehumidification system is numerically investigated. The liquid desiccant dehumidification unit employs a counter-flow low-cost and efficient heat and mass exchange core, improving the thermal performance and eliminating desiccant carryover...... that the dehumidifier effectiveness is directly proportional to the intake air temperature, intake air relative humidity and liquid desiccant flow rate where the effectiveness is inversely proportional to the intake air velocity and the heat exchanger air channel height....

Behavior of cross flow heat exchangers during the cooling and dehumidification of air

Energy Technology Data Exchange (ETDEWEB)

Ober, C [Karlsruhe Univ. (TH) (Germany, F.R.). Inst. fuer Mess- und Regelungstechnik mit Maschinenlaboratorium

1980-09-01

The task of cross flow heat exchangers in room air engineering consists on the one hand in heating up the air and, on the other hand, in the simultaneous cooling and dehumidification. The facilities used for this purpose generally are multi-row finned pipe heat exchangers which when used for cooling contain cold water or brine as the working fluid. The use of directly evaporating freezing mixtures may not be included in this consideration. The model establishment for the dynamic and the static behavior of multi-row cross flow heat exchangers during cooling and dehumidification of air has been derived in this contribution. The representation is performed for the dynamic case in the complex, display range of the Laplace transformation. A comparison with experimental results can be done very simply by means of measurements of the frequency-responce curves in the form of Bode diagrams. The description of the static behaviour may be applied as a basis for humidity controls with more favourable energy utilization.

Status and prospects of nuclear desalination

International Nuclear Information System (INIS)

Kupitz, J.; Konishi, T.

2000-01-01

While availability of potable water is an important prerequisite for socio-economic development, about 1/3 of the world's population is suffering from inadequate potable water supplies. Seawater desalination with nuclear energy could help to cope with the fresh water shortages and several countries are investigating nuclear desalination. Status and future prospects of nuclear desalination and the role of the IAEA in this area are discussed in this paper. (author)

Desalination for a thirsty world

International Nuclear Information System (INIS)

Anon.

2010-01-01

Shortages of fresh water for some, unbridled consumption by others create intolerable planetary imbalances. The treatment of seawater and brackish water can really be effective in readjusting this inequality. Because they are reliable and efficient and their output is stable, the techniques preferred by the desalination industry are thermal distillation and reverse osmosis. Because thermal distillation processes consume considerable energy, they are often paired with gas-, coal- or fuel oil-fired heating plant to take advantage of the steam produced. More than three-quarters of this energy is effectively used to preheat the seawater. In the nuclear option (fresh water + electric power), the reactors simultaneously produce fresh water and electric power, ensuring a stable, continuous supply of energy. A portion of the steam produced by the turbine of the plant's secondary circuit is customarily used to run the alternator to generate electricity. The other portion can be fed to a desalination installation, which may be composed of a combination of several systems (hybrid installations). Highly competitive, this type of cogeneration is particularly appropriate for large scale desalination installations. This is the case for some of the Gulf Emirates and for Jordan: both are investigating the nuclear option to cover their electric power and fresh water requirements. The first nuclear desalination plant dedicated to producing fresh water was built for the city of Aktau (170,000 inhabitants) in Kazakhstan on the Caspian Sea in 1963 and continued operation through 1999. Experiments for producing potable water are taking place in India, Pakistan, Egypt and Libya. In Japan, around ten small desalination units coupled with nuclear power plants produce fresh water for industrial use, and nuclear-run district heating projects are currently being developed in Russia and China. The problem of what to do with the hyper-saline brine produced by desalination and its affect on

Using EnergyPlus to Perform Dehumidification Analysis on Building America Homes: Preprint

Energy Technology Data Exchange (ETDEWEB)

Fang, X.; Winkler, J.; Christensen, D.

2011-03-01

A parametric study was conducted using EnergyPlus version 6.0 to investigate humidity issues on a typical mid-1990s reference home, a 2006 International Energy Conservation Code home, and a high-performance home in a hot-humid climate. The impacts of various dehumidification equipment and controls are analyzed on the high performance home. The study examined the combined effects of infiltration and mechanical ventilation with balanced and unbalanced mechanical ventilation systems. Indoor relative humidity excursions were examined; specifically, the number of excursions, average excursion length, and maximum excursion length. Space relative humidity, thermal comfort, and whole-house source energy consumption were analyzed for indoor relative humidity set points of 50%, 55%, and 60%. The study showed and explained why similar trends of high humidity were observed in all three homes regardless of energy efficiency, and why humidity problems are not necessarily unique in high-performance homes. Thermal comfort analysis indicated that occupants are unlikely to notice indoor humidity problems. The study confirmed that supplemental dehumidification should be provided to maintain space relative humidity below 60% in a hot-humid climate.

State-of-art report on the seawater desalination process

International Nuclear Information System (INIS)

Hwang, Young Dong; Kim, Young In; Lee, Doo Jung; Chang, Moon Hee

2000-11-01

Desalination technologies have been developed over the last 40 years and become a reliable industrial process for water production from sea or blackish water. At present, various desalination processes are available for the effective use of seawater or blackish water as valuable water resources. Since a large amount of energy is required for seawater desalination, the cost of energy is important for desalination. For the regions of severe water shortage, however, desalination is the most economical way of water supply compare to any other alternatives. Currently, water supply by seawater desalination is being increased in the areas of the Caribbean, North African and Middle East. Also, desalination of blackish water is being increased in the south-east region of USA. In general, the distillation process and the membrane technology are used for seawater esalination and the membrane and the electric-dialysis for blackish water. However, the selection of the desalination process is highly dependent on the use of produced water and the local environmental conditions where the desalination plant installed. The local condition is the most important parameters for the selection of the desalination process

State-of-art report on the seawater desalination process

Energy Technology Data Exchange (ETDEWEB)

Hwang, Young Dong; Kim, Young In; Lee, Doo Jung; Chang, Moon Hee

2000-11-01

Desalination technologies have been developed over the last 40 years and become a reliable industrial process for water production from sea or blackish water. At present, various desalination processes are available for the effective use of seawater or blackish water as valuable water resources. Since a large amount of energy is required for seawater desalination, the cost of energy is important for desalination. For the regions of severe water shortage, however, desalination is the most economical way of water supply compare to any other alternatives. Currently, water supply by seawater desalination is being increased in the areas of the Caribbean, North African and Middle East. Also, desalination of blackish water is being increased in the south-east region of USA. In general, the distillation process and the membrane technology are used for seawater esalination and the membrane and the electric-dialysis for blackish water. However, the selection of the desalination process is highly dependent on the use of produced water and the local environmental conditions where the desalination plant installed. The local condition is the most important parameters for the selection of the desalination process.

Implication of dual-purpose nuclear desalination plants

International Nuclear Information System (INIS)

Kutbi, I.I.

1983-01-01

Available dual purpose nuclear desalination schemes are reviewed. Three specific issues namely, impact of availability and reliability of the desalination stage of the plant, integration of the desalination and power production stages and new safety concerns of dual system, relating to desalination schemes are discussed. Results of operational and reliability studies of nuclear power stations, reverse osmosis and multistage flash distillation desalination plants are considered. Operational aspects of nuclear-multistage flash distillation, nuclear-reverse osmosis and nuclear-multistage flash distillation-reverse osmosis are compared. Concludes that the combined nuclear-multistage flash distillation-reverse osmosis plant arrangement permits very large production capacity, high availability, improvement of plant reliability and proovision of savings on the cost of water and power produced. 23 Ref

Humidification tower for humid air gas turbine cycles: Experimental analysis

International Nuclear Information System (INIS)

Traverso, A.

2010-01-01

In the HAT (humid air turbine) cycle, the humidification of compressed air can be provided by a pressurised saturator (i.e. humidification tower or saturation tower), this solution being known to offer several attractive features. This work is focused on an experimental study of a pressurised humidification tower, with structured packing. After a description of the test rig employed to carry out the measuring campaign, the results relating to the thermodynamic process are presented and discussed. The experimental campaign was carried out over 162 working points, covering a relatively wide range of possible operating conditions. It is shown that the saturator behaviour, in terms of air outlet humidity and temperature, is primarily driven by, in decreasing order of relevance, the inlet water temperature, the inlet water over inlet dry air mass flow ratio and the inlet air temperature. The exit relative humidity is consistently over 100%, which may be explained partially by measurement accuracy and droplet entrainment, and partially by the non-ideal behaviour of air-steam mixtures close to saturation. Experimental results have been successfully correlated using a set of new non-dimensional groups: such a correlation is able to capture the air outlet temperature with a standard deviation σ = 2.8 K.

Randomized controlled trial on postoperative pulmonary humidification after total laryngectomy: External humidifier versus heat and moisture exchanger

NARCIS (Netherlands)

Mérol, Jean-Claude; Charpiot, Anne; Langagne, Thibault; Hémar, Patrick; Ackerstaff, Annemieke H.; Hilgers, Frans J. M.

2012-01-01

Objectives/Hypothesis: Assessment of immediate postoperative airway humidification after total laryngectomy (TLE), comparing the use of an external humidifier (EH) with humidification through a heat and moisture exchanger (HME). Study Design: Randomized controlled trial (RCT). Methods: Fifty-three

Randomized controlled trial on postoperative pulmonary humidification after total laryngectomy: external humidifier versus heat and moisture exchanger

NARCIS (Netherlands)

Mérol, J.-C.; Charpiot, A.; Langagne, T.; Hémar, P.; Ackerstaff, A.H.; Hilgers, F.J.M.

2012-01-01

Objectives/Hypothesis: Assessment of immediate postoperative airway humidification after total laryngectomy (TLE), comparing the use of an external humidifier (EH) with humidification through a heat and moisture exchanger (HME). Study Design: Randomized controlled trial (RCT). Methods: Fifty-three

Feasibility and economic analysis of solid desiccant wheel used for dehumidification and preheating in blast furnace: A case study of steel plant, Nanjing, China

International Nuclear Information System (INIS)

Guan, Yipeng; Zhang, Yufeng; Sheng, Ying; Kong, Xiangrui; Du, Song

2015-01-01

To overcome the shortcomings of huge energy consumption from conventional dehumidification using lithium bromide adsorption refrigerating (LBARD) system, a novel desiccant wheel dehumidification and preheating (DWDP) system using two-stage desiccant wheel for blast furnace is brought forward. The DWDP system was designed for dehumidification and preheating in blast furnace of steel plant. It takes waste heat in the slag flushing water as desiccant regeneration and preheating energy. To validate the feasibility of the new DWDP system, experimental studies were conducted based on a steel plant in Nanjing, China. The experiment was designed to use DWDP system in humid outdoor climates e.g. summer seasons. The experimental results indicate that the moisture removal capacity of DWDP system can reach 8.7 g/kg which will lead to the improvement of steel production by 0.9% and the coal is saved of about 2100 tons per year. With the DWDP system, the energy consumed by cooling tower of slag flushing water can decrease 7.3%. All of these energy saved equates to 10.3 million CNY annually. A comparison of initial investment and operating cost between DWDP system and LBRAD system was then carried out. The results show that the initial investment and operating cost of DWDP system is 37% and 57% of present LBARD system, and the payback period is shortened 66%. - Highlights: • A novel two-stage desiccant wheel dehumidification system for blast furnace is proposed. • Average moisture removal of 8.7 g/kg is achieved and dehumidification efficiency is 47%. • Outlet humidity ratio is less than 10 g/kg that satisfies the requirement of blast air. • Waste heat in slag flushing water is utilized and 61.4 million kJ is saved annually. • The investment and operating cost is 37% and 57% of former dehumidification system

Drying hard maple (Acer saccharum L.) lumber in a small dehumidification kiln

Science.gov (United States)

Neal. Bennett

2013-01-01

Portable sawmill owners quickly recognize the advantage to kiln drying lumber they produce. Having the ability to provide properly kiln-dried lumber opens new market opportunities and can increase profit margins. However, the construction and operation of a dry kiln must be economical and simple. A small dehumidification dry kiln constructed and tested in Princeton, WV...

Provision of Desalinated Irrigation Water by the Desalination of Groundwater within a Saline Aquifer

Directory of Open Access Journals (Sweden)

David D. J. Antia

2016-12-01

Full Text Available Irrigated land accounts for 70% of global water usage and 30% of global agricultural production. Forty percent of this water is derived from groundwater. Approximately 20%–30% of the groundwater sources are saline and 20%–50% of global irrigation water is salinized. Salinization reduces crop yields and the number of crop varieties which can be grown on an arable holding. Structured ZVI (zero valent iron, Fe0 pellets desalinate water by storing the removed ions as halite (NaCl within their porosity. This allows an “Aquifer Treatment Zone” to be created within an aquifer, (penetrated by a number of wells (containing ZVI pellets. This zone is used to supply partially desalinated water directly from a saline aquifer. A modeled reconfigured aquifer producing a continuous flow (e.g., 20 m3/day, 7300 m3/a of partially desalinated irrigation water is used to illustrate the impact of porosity, permeability, aquifer heterogeneity, abstraction rate, Aquifer Treatment Zone size, aquifer thickness, optional reinjection, leakage and flow by-pass on the product water salinity. This desalination approach has no operating costs (other than abstraction costs (and ZVI regeneration and may potentially be able to deliver a continuous flow of partially desalinated water (30%–80% NaCl reduction for $0.05–0.5/m3.

Use of a new novel humidification system with high frequency percussive ventilation in a patient with inhalation injury.

Science.gov (United States)

Jones, Samuel W; Short, Kathy A; Joseph, Mark; Sommer, Courtney; Cairns, Bruce A

2010-01-01

Historically, it has been difficult to provide adequate humidification delivery with the high frequency percussive ventilator (HFPV) used in many burn centers. It is possible burn centers have avoided using HFPV because of the risk of mucus plugging, dried secretions, and cast formation. Experiences with HFPV provided doubt that the HFPV ventilator circuit could supply adequate humidification to patients receiving this mode of ventilation. Independent gas-flow delivery through the ventilator circuit inherent in HFPV provided a challenge in maintaining adequate humidification delivery to the patient. This report describes a dramatic reduction in dried, inspissated secretions by using a novel new humidification device with HFPV. The new device called the Hydrate Omni (Hydrate, Inc., Midlothian, VA) uses a small ceramic disk to provide fine water particles delivered by a pump to the HFPV circuit. This new device may alleviate previous concerns related to the delivery of adequate humidification with the HFPV. This case report was approved by the University of North Carolina School of Medicine Institutional Review Board.

The national project on nuclear desalination in India

International Nuclear Information System (INIS)

Misra, B.M.

1996-01-01

BARC (Bhabha Atomic Research Centre) has successfully developed both thermal and membrane desalination technologies for seawater and brackish water desalination. 425 m 3 /d Multi-Stage-Flash (MSF) desalination plant producing good quality water from seawater suitable for drinking and industrial water requirements operated. Knowhow developed for Low Temperature Vacuum Evaporation (LTVE) desalination plants utilizing waste heat. Reverse Osmosis (RO) technology developed at the centre has been successfully demonstrated. The experience obtained from the above plants has been utilized for designing a large scale hybrid desalination plant based on MSF and RO for augmenting the drinking water supply in water scarcity coastal areas

Evaluating a tobacco leaf humidification system involving nebulisation

Directory of Open Access Journals (Sweden)

Néstor Enrique Cerquera Peña

2010-05-01

Full Text Available A tobacco leaf humidifying system involving nebulisation was designned, implemented and evaluated; it had a system for monitoring and recording environmental conditions thereby producing an environment having more homogeneous relative humidity, ensuring better water use, better control of relative humidity and better control in managing cured tobacco leaf moisture content, thereby leading to a consequent improvement in final product quality. 55% to 75% relative humidity and 4 to 6 hour working ranges were obtained to en- sure leaf humidification reached 16% humidity on a wet basis. Two new designs are proposed for the conditioning stage regarding this conditioning chamber’s operational management, based on the results and field observations, which would allow better leaf management, thereby avoiding the risk of losses due to manipulation and over-humidification. This work strengthens research in the field of tobacco pos- tharvest technology, complementing other research projects which have been carried out in Colombia.

Energy efficient air inlet humidity control; Energiezuinige inblaasvochtregeling

Energy Technology Data Exchange (ETDEWEB)

Gielen, J.H. [C Point, DLV Plant, Horst (Netherlands)

2005-03-15

This project report describes the results of research conducted on the control of the inlet, humidification and dehumidification, based on the air inlet humidity rate. The project was carried out at a mushroom cultivation business in Heijen, the Netherlands [Dutch] Deze projectrapportage geeft de resultaten van het onderzoek naar het regelen van de luchtklep, bevochtiging en ontvochtiging, op basis van het inblaasvochtgehalte. Het project werd uitgevoerd op een champignonkwekerij in Heijen.

Humidification during high-frequency oscillatory ventilation for adults: a bench study.

Science.gov (United States)

Chikata, Yusuke; Imanaka, Hideaki; Ueta, Masahiko; Nishimura, Masaji

2010-12-01

High-frequency oscillatory ventilation (HFOV) has recently been applied to acute respiratory distress syndrome patients. However, the issue of humidification during HFOV has not been investigated. In a bench study, we evaluated humidification during HFOV for adults to test if adequate humidification was achieved in 2 different HFOV systems. We tested 2 brands of adult HFOV ventilators, the R100 (Metran, Japan) and the 3100B (SensorMedics, CA), under identical bias flow. A heated humidifier consisting of porous hollow fiber (Hummax II, Metran) was set for the R100, and a passover-type heated humidifier (MR850, Fisher & Paykel) was set for the 3100B, while inspiratory heating wire was applied to both systems. Each ventilator was connected to a lung model in an incubator. Absolute humidity, relative humidity and temperature at the airway opening were measured using a hygrometer under a variety of ventilatory settings: 3 stroke volumes/amplitudes, 3 frequencies, and 2 mean airway pressures. The R100 ventilator showed higher absolute humidity, higher relative humidity, and lower temperature than the 3100B. In the R100, as stroke volume and frequency increased, absolute humidity and temperature increased. In the 3100B, amplitude, frequency, and mean airway pressure minimally affected absolute humidity and temperature. Relative humidity was almost 100% in the R100, while it was 80.5±2.3% in the 3100B. Humidification during HFOV for adults was affected by stroke volume and frequency in the R100, but was not in the 3100B. Absolute humidity was above 33 mgH_2 O/L in these 2 systems under a range of settings.

Thermal coupling system analysis of a nuclear desalination plant

International Nuclear Information System (INIS)

Adak, A.K.; Srivastava, V.K.; Tewari, P.K.

2010-01-01

When a nuclear reactor is used to supply steam for desalination plant, the method of coupling has a significant technical and economic impact. The exact method of coupling depends upon the type of reactor and type of desalination plant. As a part of Nuclear Desalination Demonstration Project (NDDP), BARC has successfully commissioned a 4500 m 3 /day MSF desalination plant coupled to Madras Atomic Power Station (MAPS) at Kalpakkam. Desalination plant coupled to nuclear power plant of Pressurized Heavy Water Reactor (PHWR) type is a good example of dual-purpose nuclear desalination plant. This paper presents the thermal coupling system analysis of this plant along with technical and safety aspects. (author)

Fabrication and Properties of Micro-Nanoencapsulated Phase Change Materials for Internally-Cooled Liquid Desiccant Dehumidification

Directory of Open Access Journals (Sweden)

Xiaofeng Niu

2017-04-01

Full Text Available Micro-nanoencapsulated phase change materials (M-NEPCMs are proposed to be useful in liquid desiccant dehumidification by restraining the temperature rise in the moisture-removal process and improving the dehumidification efficiency. In this paper, the n-octadecane M-NEPCMs with desirable thermal properties for internally-cooled dehumidification were fabricated by using compound emulsifiers through the in-situ polymerization method. Melamine-formaldehyde resin was used as the shell material. The effects of the mixing ratio, emulsification methods and amount of the compound emulsifiers on the morphology, size and thermal properties of the M-NEPCMs were investigated experimentally. The optimum weight mixing ratio of the compound emulsifiers is SDS (sodium dodecyl sulfate:Tween80 (polyoxyethylene sorbitan monooleate:Span80 (sorbitan monooleate = 0.1:0.6:0.3, which achieves the best stability of the n-octadecane emulsion. When the compound emulsifiers are 10 wt. % of the core material, the melting enthalpy of M-NEPCMs reaches its maximum of 145.26 J/g of capsules, with an encapsulation efficiency of 62.88% and a mean diameter of 636 nm. The sub-cooling of the prepared M-NEPCMs is lower than 3 °C, with an acceptable thermal reliability after the thermal cycling test. A pre-emulsification prior to the addition of deionized water in the emulsification is beneficial to the morphology of the capsules, as the phase change enthalpy can be increased by 123.7%.

Fabrication and Properties of Micro-Nanoencapsulated Phase Change Materials for Internally-Cooled Liquid Desiccant Dehumidification.

Science.gov (United States)

Niu, Xiaofeng; Xu, Qing; Zhang, Yi; Zhang, Yue; Yan, Yufeng; Liu, Tao

2017-04-29

Micro-nanoencapsulated phase change materials (M-NEPCMs) are proposed to be useful in liquid desiccant dehumidification by restraining the temperature rise in the moisture-removal process and improving the dehumidification efficiency. In this paper, the n -octadecane M-NEPCMs with desirable thermal properties for internally-cooled dehumidification were fabricated by using compound emulsifiers through the in-situ polymerization method. Melamine-formaldehyde resin was used as the shell material. The effects of the mixing ratio, emulsification methods and amount of the compound emulsifiers on the morphology, size and thermal properties of the M-NEPCMs were investigated experimentally. The optimum weight mixing ratio of the compound emulsifiers is SDS (sodium dodecyl sulfate):Tween80 (polyoxyethylene sorbitan monooleate):Span80 (sorbitan monooleate) = 0.1:0.6:0.3, which achieves the best stability of the n -octadecane emulsion. When the compound emulsifiers are 10 wt. % of the core material, the melting enthalpy of M-NEPCMs reaches its maximum of 145.26 J/g of capsules, with an encapsulation efficiency of 62.88% and a mean diameter of 636 nm. The sub-cooling of the prepared M-NEPCMs is lower than 3 °C, with an acceptable thermal reliability after the thermal cycling test. A pre-emulsification prior to the addition of deionized water in the emulsification is beneficial to the morphology of the capsules, as the phase change enthalpy can be increased by 123.7%.

Numerical simulation of humidification and heating during inspiration in nose models with three different located septal perforations.

Science.gov (United States)

Lindemann, Jörg; Reichert, Michael; Kröger, Ralf; Schuler, Patrick; Hoffmann, Thomas; Sommer, Fabian

2016-07-01

Nasal septum perforations (SP) are characterized by nasal obstruction, bleeding and crusting. The disturbed heating and humidification of the inhaled air are important factors, which cause these symptoms due to a disturbed airflow. Numerical simulations offer a great potential to avoid these limitations and to provide valid data. The aim of the study was to simulate the humidification and heating of the inhaled air in digital nose models with three different SPs and without SP. Four realistic bilateral nose models based on a multi-slice CT scan were created. The SP were located anterior caudal, anterior cranial and posterior caudal. One model was without SP. A numerical simulation was performed. Boundary conditions were based on previous in vivo measurements. Heating and humidification of the inhaled air were displayed, analyzed in each model and compared to each other. Anterior caudal SPs cause a disturbed decrease of temperature and humidity of the inhaled air. The reduced temperature and humidity values can still be shown in the posterior nose. The anterior cranial and the posterior caudal perforation have only a minor influence on heating and humidification. A reduced humidification and heating of the air can be shown by numerical simulations due to SP depending on their localization. The anterior caudal SP representing a typical localization after previous surgery has the biggest influence on heating and humidification. The results explain the typical symptoms such as crusting by drying-out the nasal mucosa. The size and the localization of the SP are essential for the symptoms.

Economical analysis and study on a solar desalination unit

DEFF Research Database (Denmark)

of desalination unit and electrical power, the life time of solar desalination unit and the yearly yield of fresh water, on the cost of the fresh water production of the solar desalination unit are studied. It is helpful for the further investigation of solar desalination and for reducing the cost of fresh water...

Renewable energy-driven innovative energy-efficient desalination technologies

International Nuclear Information System (INIS)

Ghaffour, Noreddine; Lattemann, Sabine; Missimer, Thomas; Ng, Kim Choon; Sinha, Shahnawaz; Amy, Gary

2014-01-01

Highlights: • Renewable energy-driven desalination technologies are highlighted. • Solar, geothermal, and wind energy sources were explored. • An innovative hybrid approach (combined solar–geothermal) has also been explored. • Innovative desalination technologies developed by our group are discussed. • Climate change and GHG emissions from desalination are also discussed. - Abstract: Globally, the Kingdom of Saudi Arabia (KSA) desalinates the largest capacity of seawater but through energy-intensive thermal processes such as multi-stage flash (MSF) distillation (>10 kW h per m 3 of desalinated water, including electrical and thermal energies). In other regions where fossil energy is more expensive and not subsidized, seawater reverse osmosis (SWRO) is the most common desalination technology but it is still energy-intensive (3–4 kW h e /m 3 ). Both processes therefore lead to the emission of significant amounts of greenhouse gases (GHGs). Moreover, MSF and SWRO technologies are most often used for large desalination facilities serving urban centers with centralized water distribution systems and power grids. While renewable energy (RE) sources could be used to serve centralized systems in urban centers and thus provide an opportunity to make desalination greener, they are mostly used to serve rural communities off of the grid. In the KSA, solar and geothermal energy are of most relevance in terms of local conditions. Our group is focusing on developing new desalination processes, adsorption desalination (AD) and membrane distillation (MD), which can be driven by waste heat, geothermal or solar energy. A demonstration solar-powered AD facility has been constructed and a life cycle assessment showed that a specific energy consumption of <1.5 kW h e /m 3 is possible. An innovative hybrid approach has also been explored which would combine solar and geothermal energy using an alternating 12-h cycle to reduce the probability of depleting the heat source

Sustainable desalination using ocean thermocline energy

KAUST Repository

Ng, Kim Choon; Shahzad, Muhammad Wakil

2017-01-01

The conventional desalination processes are not only energy intensive but also environment un-friendly. They are operating far from thermodynamic limit, 10–12%, making them un-sustainable for future water supplies. An innovative desalination

Trombay symposium on desalination and water reuse: proceedings

International Nuclear Information System (INIS)

2007-02-01

Trombay Symposium on Desalination and Water Reuse (TSDWR-07) addresses the issues related to desalination and water reuse including integrated water resource management. It aims to bring together the desalination and water purification technologists from government R and D, academia, industry and representatives from NGOs and user groups including policy makers. The papers received cover a wide range of topics from water resource management to different aspects of desalination and water purification. Papers relevant to INIS are indexed separately

Clinical outcome associated with the use of different inhalation method with and without humidification in asthmatic mechanically ventilated patients.

Science.gov (United States)

Moustafa, Islam O F; ElHansy, Muhammad H E; Al Hallag, Moataz; Fink, James B; Dailey, Patricia; Rabea, Hoda; Abdelrahim, Mohamed E A

2017-08-01

Inhaled-medication delivered during mechanical-ventilation is affected by type of aerosol-generator and humidity-condition. Despite many in-vitro studies related to aerosol-delivery to mechanically-ventilated patients, little has been reported on clinical effects of these variables. The aim of this study was to determine effect of humidification and type of aerosol-generator on clinical status of mechanically ventilated asthmatics. 72 (36 females) asthmatic subjects receiving invasive mechanical ventilation were enrolled and assigned randomly to 6 treatment groups of 12 (6 females) subjects each received, as possible, all inhaled medication using their assigned aerosol generator and humidity condition during delivery. Aerosol-generators were placed immediately after humidifier within inspiratory limb of mechanical ventilation circuit. First group used vibrating-mesh-nebulizer (Aerogen Solo; VMN) with humidification; Second used VMN without humidification; Third used metered-dose-inhaler with AeroChamber Vent (MDI-AV) with humidification; Forth used MDI-AV without humidification; Fifth used Oxycare jet-nebulizer (JN) with humidification; Sixth used JN without humidification. Measured parameters included clinical-parameters reflected patient response (CP) and endpoint parameters e.g. length-of-stay in the intensive-care-unit (ICU-days) and mechanical-ventilation days (MV-days). There was no significant difference between studied subjects in the 6 groups in baseline of CP. VMN resulted in trend to shorter ICU-days (∼1.42days) compared to MDI-AV (p = 0.39) and relatively but not significantly shorter ICU-days (∼0.75days) compared JN. Aerosol-delivery with or without humidification did not have any significant effect on any of parameters studied with very light insignificant tendency of delivery at humid condition to decrease MV-days and ICU-days. No significant effect was found of changing humidity during aerosol-delivery to ventilated-patient. VMN to deliver

Strategies for merging microbial fuel cell technologies in water desalination processes: Start-up protocol and desalination efficiency assessment

Science.gov (United States)

Borjas, Zulema; Esteve-Núñez, Abraham; Ortiz, Juan Manuel

2017-07-01

Microbial Desalination Cells constitute an innovative technology where microbial fuel cell and electrodialysis merge in the same device for obtaining fresh water from saline water with no energy-associated cost for the user. In this work, an anodic biofilm of the electroactive bacteria Geobacter sulfurreducens was able to efficiently convert the acetate present in synthetic waste water into electric current (j = 0.32 mA cm-2) able to desalinate water. .Moreover, we implemented an efficient start-up protocol where desalination up to 90% occurred in a desalination cycle (water production:0.308 L m-2 h-1, initial salinity: 9 mS cm-1, final salinity: osmosis (RO) or reverse electrodialysis.

An experimental study of the air humidification process using a membrane contactor

Directory of Open Access Journals (Sweden)

Englart Sebastian

2017-01-01

Full Text Available The article presents the results of the experimental examination of the effectiveness of air humidification using a membrane module. The construction of the membrane module and the measuring stand is also discussed. In order to assess the effectiveness of air humidification using the membrane module, the measurements of temperature and humidity at the membrane module’s inlet and outlet, air flow rate, water flow rate and water temperature were taken. Based on the measurements, the effectiveness coefficients, E, have been determined. The power demand for the solution under study has also been discussed.

The nuclear energy in the seawater desalination

International Nuclear Information System (INIS)

Moreno A, J.; Flores E, R.M.

2004-01-01

In general, the hydric resources of diverse regions of the world are insufficient for to satisfy the necessities of their inhabitants. Among the different technologies that are applied for the desalination of seawater are the distillation processes, the use of membranes and in particular recently in development the use of the nuclear energy (Nuclear Desalination; System to produce drinkable water starting from seawater in a complex integrated in that as much the nuclear reactor as the desalination system are in a common location, the facilities and pertinent services are shared, and the nuclear reactor produces the energy that is used for the desalination process). (Author)

Use of nuclear reactors for seawater desalination

International Nuclear Information System (INIS)

1990-09-01

The last International Atomic Energy Agency (IAEA) status report on desalination, including nuclear desalination, was issued nearly 2 decades ago. The impending water crisis in many parts of the world, and especially in the Middle East, makes it appropriate to provide an updated report as a basis for consideration of future activities. This report provides a state-of-the-art review of desalination and pertinent nuclear reactor technology. Information is included on fresh water needs and costs, environmental risks associated with alternatives for water production, and data regarding the technical and economic characteristics of immediately available desalination systems, as well as compatible nuclear technology. 68 refs, 60 figs, 11 tabs

Thermal desalination in GCC and possible development

KAUST Repository

Darwish, Mohamed Ali

2013-01-01

The Water Desalination and Reuse Center in King Abdulla University of Science and Technology, in Saudi Arabia, held a workshop on thermal desalination on the 11th and 12th of March, 2013. This paper was presented as part of a lecture at the workshop. It presents the status and possible developments of the two main thermal desalination systems processing large quantities of seawater in the Gulf Cooperation Council, multi-stage flash, and thermal vapor compression systems. Developments of these systems were presented to show how these systems are competing with the more energy-efficient seawater reverse osmosis desalting. © 2013 © 2013 Balaban Desalination Publications. All rights reserved.

Thermal desalination in GCC and possible development

KAUST Repository

Darwish, Mohamed Ali

2013-06-28

The Water Desalination and Reuse Center in King Abdulla University of Science and Technology, in Saudi Arabia, held a workshop on thermal desalination on the 11th and 12th of March, 2013. This paper was presented as part of a lecture at the workshop. It presents the status and possible developments of the two main thermal desalination systems processing large quantities of seawater in the Gulf Cooperation Council, multi-stage flash, and thermal vapor compression systems. Developments of these systems were presented to show how these systems are competing with the more energy-efficient seawater reverse osmosis desalting. © 2013 © 2013 Balaban Desalination Publications. All rights reserved.

Water vapor permeation and dehumidification performance of poly(vinyl alcohol)/lithium chloride composite membranes

KAUST Repository

Bui, Duc Thuan

2015-10-09

Thin and robust composite membranes comprising stainless steel scaffold, fine and porous TiO2 and polyvinyl alcohol/lithium chloride were fabricated and studied for air dehumidification application. Higher hydrophilicity, sorption and permeation were observed for membranes with increased lithium chloride content up to 50%. The permeation and sorption properties of the membranes were investigated under different temperatures. The results provided a deeper insight into the membrane water vapor permeation process. It was specifically noted that lithium chloride significantly reduces water diffusion energy barrier, resulting in the change of permeation energy from positive to negative values. Higher water vapor permeance was observed for the membrane with higher LiCl content at lower temperature. The isothermal air dehumidification tests show that the membrane is suitable for dehumidifying air in high humid condition. Additionally, results also indicate a trade-off between the humidity ratio drop with the water vapor removal rate when varying air flowrate.

The application of nuclear energy for seawater desalination. The Candesal nuclear desalination system

International Nuclear Information System (INIS)

Humphries, J.R.; Sweeney, C.B.

1997-01-01

As the global consumption of water increases with growing population and rising levels of industrialization, major new sources of potable water production must be developed. Desalination of seawater is an energy intensive process which brings with it a demand for additional energy generation capacity. The Candesal nuclear desalination/cogeneration system has been developed to address both requirements, providing improved water production efficiency and lower costs. To meet large scale water production requirements the Candesal system integrates a nuclear energy source, such as the CANDU reactor, with a reverse osmosis (ro) desalination facility, capturing the waste heat from the electrical generation process to improve the efficiency of the ro process. By also using advanced feed water pre-treatment and sophisticated system design integration and optimization techniques, the net results is a substantial improvement in energy efficiency, economics, and environmental impact. The design is also applicable to a variety of conventional energy sources, and applies over the full range of desalination plant sizes. Since potable water production is based on membrane technology, brackish water and tertiary effluent from waste water treatment can also be used as feed streams to the system. Also considered to be a fundamental component of the Candesal philosophy is a technology transfer program aimed at establishing a complete local capability for the design, fabrication, operation and maintenance of these facilities. Through a well defined and logical technology transfer program, the necessary technologies are integrated into a nation's industrial capability and infrastructure, thus preparing local industry for the long term goal of manufacturing large scale, economical and environmentally benign desalination facilities. (author). 8 refs, 3 figs

Status of nuclear desalination in IAEA member states

International Nuclear Information System (INIS)

2007-01-01

Some of the IAEA Member States have active nuclear desalination programmes and, during the last few years, substantial overall progress has been made in this field. As part of the ongoing activities within the IAEA's nuclear power programme, it was thus decided to prepare a status report, which would briefly describe the recent nuclear seawater desalination related developments and relevant IAEA activities. This status report briefly covers salient aspects of the new generation reactors and a few innovative reactors being considered for desalination and other non-electrical applications, the recent advances in the commonly employed desalination processes and their coupling to nuclear reactors. A summary of techno-economic feasibility studies carried out in interested Member States has been presented and the potable water cost reduction strategies from nuclear desalination plants have been discussed. The socio-economic and environmental benefits of nuclear power driven desalination plants have been elaborated. It is expected that the concise information provided in this report would be useful to the decision makers in the Member States and would incite them to consider or to accelerate the deployment of nuclear desalination projects in their respective countries

Costing methods for nuclear desalination

International Nuclear Information System (INIS)

1966-01-01

The question of the methods used for costing desalination plants has been recognized as very important in the economic choice of a plant and its optimization. The fifth meeting of the Panel on the Use of Nuclear Energy in Saline Water Conversion, convened by the International Atomic Energy Agency in April 1965, noted this fact and recommended the preparation of a report on suitable methods for costing and evaluating nuclear desalination schemes. The Agency has therefore prepared this document, which was reviewed by an international panel of experts that met in Vienna from 18 to 22 April, 1966. The report contains a review of the underlying principles for costing desalination plants and of the various methods that have been proposed for allocating costs in dual-purpose plants. The effect of the different allocation methods on the water and power costs is shown at the end of the report. No attempt is made to recommend any particular method, but the possible limitations of each are indicated. It is hoped that this report will help those involved in the various phases of desalination projects

Enhancing forward osmosis water recovery from landfill leachate by desalinating brine and recovering ammonia in a microbial desalination cell.

Science.gov (United States)

Iskander, Syeed Md; Novak, John T; He, Zhen

2018-05-01

In this work, a microbial desalination cell (MDC) was employed to desalinate the FO treated leachate for reduction of both salinity and chemical oxygen demand (COD). The FO recovered 51.5% water from a raw leachate and the recovery increased to 83.5% from the concentrated leachate after desalination in the MDC fed with either acetate or another leachate as an electron source and at a different hydraulic retention time (HRT). Easily-degraded substrate like acetate and a long HRT resulted in a low conductivity desalinated effluent. Ammonia was also recovered in the MDC cathode with a recovery efficiency varying from 11 to 64%, affected by current generation and HRT. Significant COD reduction, as high as 65.4%, was observed in the desalination chamber and attributed to the decrease of both organic and inorganic compounds via diffusion and electricity-driven movement. Copyright © 2018 Elsevier Ltd. All rights reserved.

New Technologies for Seawater Desalination Using Nuclear Energy

International Nuclear Information System (INIS)

2015-01-01

As seawater desalination technologies are rapidly evolving and more States are opting for dual purpose integrated power plants (i.e. cogeneration), the need for advanced technologies suitable for coupling to nuclear power plants and leading to more efficient and economic nuclear desalination systems is obvious. The Coordinated Research Programme (CRP) New Technologies for Seawater Desalination using Nuclear Energy was organized in the framework of the Technical Working Group on Nuclear Desalination (TWG-ND). The TWGND was established in 2008 with the purpose of advising the IAEA Deputy Director General and promoting the exchange of technical information on national programmes in the field of seawater desalination using nuclear energy. This CRP project was conducted within the Nuclear Power Technology Development Section of the IAEA. It was launched in 2009 and completed by 2011, with research proposals received from nine Member States: Algeria, Egypt, France, India, Indonesia, Pakistan, the Syrian Arab Republic, the United Kingdom and the United States of America. The project aimed to review innovative technologies for seawater desalination which could be coupled to main types of existing nuclear power plant. Such coupling is expected to help making nuclear desalination safer and more economical, and hence more attractive for newcomer States interested in nuclear desalination. The project also aimed to collect ideas and suggestions necessary to update the IAEA desalination economic evaluation program (DEEP) software to become more robust and versatile. The specific objectives of the project were the introduction of innovative technologies and their economic viability, which could help make nuclear desalination a globally viable option for the safe and sustainable production of fresh water. The technologies under scrutiny in this CRP involve the low temperature horizontal tube multi-effect distillation, heat recovery systems using heat pipe based heat exchangers

Water Desalination using geothermal energy

KAUST Repository

Goosen, M.

2010-08-03

The paper provides a critical overview of water desalination using geothermal resources. Specific case studies are presented, as well as an assessment of environmental risks and market potential and barriers to growth. The availability and suitability of low and high temperature geothermal energy in comparison to other renewable energy resources for desalination is also discussed. Analysis will show, for example, that the use of geothermal energy for thermal desalination can be justified only in the presence of cheap geothermal reservoirs or in decentralized applications focusing on small-scale water supplies in coastal regions, provided that society is able and willing to pay for desalting. 2010 by the authors; licensee MDPI, Basel, Switzerland.

Electrokinetic desalination of glazed ceramic tiles

DEFF Research Database (Denmark)

Ottosen, Lisbeth M.; Ferreira, Celia; Christensen, Iben Vernegren

2010-01-01

Electrokinetic desalination is a method where an applied electric DC field is the driving force for removal of salts from porous building materials. In the present paper, the method is tested in laboratory scale for desalination of single ceramic tiles. In a model system, where a tile...... was contaminated with NaCl during submersion and subsequently desalinated by the method, the desalination was completed in that the high and problematic initial Cl(-) concentration was reduced to an unproblematic concentration. Further conductivity measurements showed a very low conductivity in the tile after...... treatment, indicating that supply of ions from the poultice at the electrodes into the tile was limited. Electroosmotic transport of water was seen when low ionic content was reached. Experiments were also conducted with XVIII-century tiles, which had been removed from Palacio Centeno (Lisbon) during...

Changes in ocular and nasal signs and symptoms among air crew in relation to air humidification on intercontinental flights.

Science.gov (United States)

Norbäck, Dan; Lindgren, Torsten; Wieslander, Gunilla

2006-04-01

This study evaluates the influence of air humidification in aircraft on symptoms, tear-film stability, nasal patency, and peak expiratory flow. Commercial air crew (N=71) were given a medical examination during eight flights from Stockholm to Chicago and eight flights in the opposite direction. Examinations were done onboard one Boeing 767 aircraft equipped with an evaporation humidifier in the forward part of the cabin. The investigators followed the air crew, staying one night in Chicago and returning with the same crew. Four of the flights had the air humidification device active in-flight to Chicago and deactivated when returning to Stockholm. The other four flights had the inverse humidification sequence. The humidification sequence was randomized and double blind. Hygienic measurements were performed. The humidification increased the relative air humidity by 10% in the 1st row in business class, by 3% in the last row (39th row) in tourist class, and by 3% in the cockpit. Air humidification increased tear-film stability and nasal patency and decreased ocular, nasal, and dermal symptoms and headache. The mean concentration of viable bacteria [77-108 colony-forming units (cfu)/m(3)], viable molds (74-84 cfu/m(3)), and particulate matter (1-8 microg/m(3)) was low, both during the humidified and non-humidified flights. Relative air humidity is low (10-12%) during intercontinental flights and can be increased by the use of a ceramic evaporation humidifier, without any measurable increase of microorganisms in cabin air. Air humidification could increase passenger and crew comfort by increasing tear-film stability and nasal patency and reducing various symptoms.

World interest in nuclear desalination

International Nuclear Information System (INIS)

1969-01-01

Nuclear power will be used in a desalination plant for the first time in a USSR plant now nearing completion. Studies are in progress to expand the concept of linking the power to chemical industries. These and other developing ideas were subjects of keen discussion by world experts at an Agency conference on nuclear desalination in Madrid. (author)

Airway humidification with a heated wire humidifier during high-frequency ventilation using Babylog 8000 plus in neonates.

Science.gov (United States)

Nagaya, Ken; Okamoto, Toshio; Nakamura, Eiki; Hayashi, Tokitsugi; Fujieda, Kenji

2009-03-01

Little data are available on airway humidity during high-frequency ventilation (HFV). Our purpose is to evaluate the airway humidification during HFV. We examined the airway humidification and temperature in a neonatal HFV system using Babylog 8000 plus. The absolute humidity (AH), relative humidity (RH), and temperature at different sites and under different HFV conditions were compared with those during conventional intermittent positive pressure ventilation (IPPV). The mean AH and RH at the patient end of the respiratory circuit under 37 degrees C in the humidification chamber (HC) during HFV were less than 35 mg/L and 65%, respectively, while those during IPPV were 42.3 mg/L and 96.8%, respectively. The humidification at the outlet of the HC was similar results. Moreover, during HFV an increase in the bias-flow of ventilator led to a further decrease in the humidity at the patient end of respiratory circuit and the outlet of HC. It was necessary to set the temperature in the HC at >39 degrees C to maintain adequate humidity at the HC and the patient end of respiratory circuit during HFV. An increase in the incubator temperature led to an increase in the temperature at the patient end of the respiratory circuit. The temperature at the patient end of the respiratory circuit was about 39-40 degrees C when the incubator temperature was 35-37 degrees C. The airway humidification at the patient end of respiratory circuit and the outlet of HC in HFV were poorer than those in IPPV. However, the adequacy of humidification and safety in HFV remain to be demonstrated in clinical practice.

Effects of air conditioning, dehumidification and natural ventilation on indoor concentrations of 222Rn and 220Rn

International Nuclear Information System (INIS)

Lee, Thomas K.C.; Yu, K.N.

2000-01-01

A bedroom was selected for detailed measurements on 220 Rn and 222 Rn concentrations and environmental parameters including CO 2 concentration, temperature and relative humidity. To simulate different sealing conditions, five conditions were artificially created in the sampling period of 25 consecutive days. It was concluded that natural ventilation is the most efficient way to lower the 222 Rn levels, while air conditioning is the next. Dehumidification provides only a marginal reduction of 222 Rn levels. The 220 Rn concentrations are not affected by natural ventilation, air conditioner or dehumidification, and were all around 10 Bq m -3 . There are no significant correlations between the 220 Rn and 222 Rn concentrations and environmental conditions such as CO 2 concentrations, temperature, relative humidity and pressure

Solar-Powered Desalination: A Modelling and Experimental Study

Science.gov (United States)

Leblanc, Jimmy; Andrews, John

2007-10-01

Water shortage is becoming one of the major problems worldwide. As such, desalination technologies have been implemented to meet growing demands for fresh water. Among the desalination technologies, thermal desalination, including multi stage flash (MSF) and multi effect evaporation (MEE), is the current leading desalination process. Reverse osmosis (RO) is also being increasingly used. Despite technological improvements, thermal desalination and reverse osmosis continue to be intensive fossil-fuel consumers and contribute to increased levels of greenhouse gases. As energy costs rise, thermal desalination by solar energy and/or low cost waste heat is likely to become increasingly attractive. As part of a project investigating the productive use of saline land and the development of sustainable desalination systems, the feasibility of producing potable water from seawater or brackish water using desalination systems powered by renewable energy in the form of low-temperature solar-thermal sources has been studied. A salinity-gradient solar pond and an evacuated tube solar collector system have been used as heat sources. Solar ponds combine solar energy collection with long-term storage and can provide reliable thermal energy at temperature ranges from 50 to 90 °C. A visual basic computer model of the different multi-stage flash desalination processes coupled with a salinity-gradient solar pond was developed to determine which process is preferable in regards to performance and greenhouse impact. The governing mathematical equations are derived from mass balances, heat energy balances, and heat transfer characteristics. Using the results from the modelling, a small-scale solar-powered desalination system, capable of producing up to 500 litres of fresh water per day, was designed and manufactured. This single-stage flash system consists of two main units: the heat supply and storage system and the flash desalination unit. Two different condenser heat exchanger

Impact of socio-economic growth on desalination in the US.

Science.gov (United States)

Ziolkowska, Jadwiga R; Reyes, Reuben

2016-02-01

In 2013, around 1336 desalination plants in the United States (US) provided purified water mainly to municipalities, the industry sector and for power generation. In 2013 alone, ∼200 million m(3) of water were desalinated; the amount that could satisfy annual municipal water consumption of more than 1.5 million people in the US. Desalination has proven to be a reliable water supply source in many countries around the world, with the total global desalination capacity of ∼60 million m(3)/day in 2013. Desalination has been used to mitigate water scarcity and lessen the pressure on water resources. Currently, data and information about desalination are still limited, while extensive socio-economic analyses are missing. This paper presents an econometric model to fill this gap. It evaluates the impact of selected socio-economic variables on desalination development in the US in the time span 1970-2013. The results show that the GDP and population growth have significantly impacted the desalination sector over the analyzed time period. The insights into the economics of desalination provided with this paper can be used to further evaluate cost-effectiveness of desalination both in the US and in other countries around the world. Copyright © 2015 Elsevier Ltd. All rights reserved.

Coupling of AST-500 heating reactors with desalination facilities

International Nuclear Information System (INIS)

Kourachenkov, A.V.

1998-01-01

The general issues regarding NHR and desalination facility joint operation for potable water production are briefly considered. AST-500 reactor plant and DOU GTPA-type evaporating desalination facilities, both relying on proven technology and solid experience of construction and operation, are taken as a basis for the design of a large-output nuclear desalination complex. Its main design characteristics are given. Similarity of NHR operation for a heating grid and a desalination facility in respect of reactor plant operating conditions and power regulation principles is pointed out. The issues of nuclear desalination complexes composition are discussed briefly as well. (author)

Sea water desalination using nuclear reactors

International Nuclear Information System (INIS)

Nisan, S.

2003-01-01

The paper first underlines the water shortage problem today and in the years to come when, around the time horizon 2020, two-thirds of the total world population would be without access to potable water. Desalination of sea-water (and, to a limited extent, that of brackish water) is shown to be an attractive solution. In this context, sea-water desalination by nuclear energy appears to be not only technically feasible and safe but also economically very attractive and a sustainable solution. Thus, compared to conventional fossil energy based sources, desalination costs by nuclear options could be 30 to 60% lower. The nuclear options are therefore expected to satisfy the fundamental water needs and electricity demands of human beings without in any way producing large amounts of greenhouse gases which any desalination strategy, based on the employment of fossil fuels, cannot fail to avoid. (author)

Energy Implications of Seawater Desalination (Invited)

Science.gov (United States)

Cooley, H.; Heberger, M. G.

2013-12-01

Freshwater has traditionally come from rivers, lakes, streams, and groundwater aquifers. As demand increases and climate change alters the location and timing of water supply, these traditional sources are becoming unavailable, more difficult, or increasingly expensive to develop. As a result, many communities are switching to alternative sources of water. Interest in pursuing seawater desalination is high in many coastal communities. In California, for example, 17 plants are proposed for development along the California coast and two in Mexico. Water managers are pursing desalination because is a local supply that can help diversify the water supply portfolio. Additionally, it is a reliable supply, which can be especially valuable during a drought. But removing the salt from seawater is an energy-intensive process that consumes more energy per gallon than most other water supply and treatment options. These energy requirements are key factors that will impact the extent and success of desalination in California. Energy requirements for seawater desalination average about 4.0 kWh per cubic meter (m3) of water produced. By comparison, the least energy-intensive options of local sources of groundwater and surface water require 0 - 0.90 kWh per m3; wastewater reuse, depending on treatment levels, may require from 0.26 - 2.2 kWh per m3. Beyond the electricity required for the desalination facility itself, producing any new source of water, including through desalination, increases the amount of energy required to deliver and use the water produced as well as collect, treat, and dispose of the wastewater generated. Energy is the largest single variable cost for a desalination plant, varying from one-third to more than one-half the cost of produced water. Building a desalination plant may reduce a water utility's exposure to water reliability risks at the added expense of an increase in exposure to energy price risk. In dependent on hydropower, electricity prices tend to

Seawater desalination with nuclear power

International Nuclear Information System (INIS)

2005-01-01

Nuclear power helps reduce costs for energy-intensive processes such as seawater desalination. A new generation of innovative small and medium nuclear power plants could co-generate electricity and potable water from seawater, both safely and at competitive prices in today's market. The IAEA provides technical support to Member States facing water shortage problems, on assessing the viability of nuclear power in seawater desalination. The support, usually channelled through national Technical Cooperation (TC) projects, can take several forms, ranging from educational training and technical advice on feasibility studies to design and safety review of demonstration projects. The IAEA offers a software tool (DEEP) that can be used to evaluate the economics of the different desalination and heat source configurations, including nuclear and fossil options

Economic competitiveness of seawater desalinated by nuclear and fossil energy

International Nuclear Information System (INIS)

Tian Li; Wang Yongqing; Guo Jilin; Liu Wei

2001-01-01

The levelized discounted production water cost method and the new desalination economic evaluation program (DEEP1.1) were used to compare the economics of desalination using nuclear or fossil energy. The results indicate that nuclear desalination is more economic than fossil desalination with reverse osmosis (RO), multi-effect distillation (MED) and multi-stage flash (MSF). The desalination water cost varies depending on the desalination technology and the water plant size from 0.52-1.98 USD·m -3 with the lowest water price by RO and the highest by MSF. The sensitivity factors for the economic competitiveness increases in order of the discounted rate, desalination plant scale, fossil fuel price, specific power plant investment, seawater temperature and total dissolve solid (TDS). The highest water cost is about 22.6% more than the base case

Physicochemical characteristics and sensory profile of honey samples from stingless bees (Apidae: Meliponinae submitted to a dehumidification process

Directory of Open Access Journals (Sweden)

Carlos A.L. Carvalho

2009-03-01

Full Text Available This study was conducted to evaluate the effect of a dehumidification process on the physicochemical and sensory characteristics of stingless-bee honey. Melipona scutellaris and M. quadrifasciata honey samples were submitted to a dehumidification process and to physicochemical (reducing sugars, apparent sucrose, moisture, diastatic activity, hydroxymethylfurfural, ash, pH, acidity, and electric conductivity and sensory evaluations (fluidity, color, aroma, crystallization,flavor,and acceptability. The results indicated that the dehumidification process does not interfere with honey quality and acceptability.Este estudo foi conduzido com o objetivo de avaliar o efeito do processo de desumidificação sobre as características físico-químicas e sensoriais do mel das abelhas sem ferrão. Amostras de méis de Melipona scutellaris e M. quadrifasciata foram submetidas ao processo de desumidificação, passando em seguida por avaliações físico-químicas (açúcares redutores, sacarose aparente, umidade, atividade diastásica, hidroximetilfurfural, cinzas, pH, acidez e condutividade elétrica e sensoriais (fluidez, cor, aroma, cristalização, sabor e aceitabilidade. Os resultados indicaram que o processo de desumidificação não interfere na qualidade e aceitabilidade do mel.

Renewable energy-driven innovative energy-efficient desalination technologies

KAUST Repository

Ghaffour, NorEddine; Lattemann, Sabine; Missimer, Thomas M.; Ng, Kim Choon; Sinha, Shahnawaz; Amy, Gary L.

2014-01-01

Globally, the Kingdom of Saudi Arabia (KSA) desalinates the largest capacity of seawater but through energy-intensive thermal processes such as multi-stage flash (MSF) distillation (>10 kW h per m3 of desalinated water, including electrical and thermal energies). In other regions where fossil energy is more expensive and not subsidized, seawater reverse osmosis (SWRO) is the most common desalination technology but it is still energy-intensive (3-4 kW h_e/m3). Both processes therefore lead to the emission of significant amounts of greenhouse gases (GHGs). Moreover, MSF and SWRO technologies are most often used for large desalination facilities serving urban centers with centralized water distribution systems and power grids. While renewable energy (RE) sources could be used to serve centralized systems in urban centers and thus provide an opportunity to make desalination greener, they are mostly used to serve rural communities off of the grid. In the KSA, solar and geothermal energy are of most relevance in terms of local conditions. Our group is focusing on developing new desalination processes, adsorption desalination (AD) and membrane distillation (MD), which can be driven by waste heat, geothermal or solar energy. A demonstration solar-powered AD facility has been constructed and a life cycle assessment showed that a specific energy consumption of <1.5 kW h_e/m3 is possible. An innovative hybrid approach has also been explored which would combine solar and geothermal energy using an alternating 12-h cycle to reduce the probability of depleting the heat source within the geothermal reservoir and provide the most effective use of RE without the need for energy storage. This paper highlights the use of RE for desalination in KSA with a focus on our group's contribution in developing innovative low energy-driven desalination technologies. © 2014 Elsevier Ltd. All rights reserved.

Renewable energy-driven innovative energy-efficient desalination technologies

KAUST Repository

Ghaffour, Noreddine

2014-04-13

Globally, the Kingdom of Saudi Arabia (KSA) desalinates the largest capacity of seawater but through energy-intensive thermal processes such as multi-stage flash (MSF) distillation (>10 kW h per m3 of desalinated water, including electrical and thermal energies). In other regions where fossil energy is more expensive and not subsidized, seawater reverse osmosis (SWRO) is the most common desalination technology but it is still energy-intensive (3-4 kW h_e/m3). Both processes therefore lead to the emission of significant amounts of greenhouse gases (GHGs). Moreover, MSF and SWRO technologies are most often used for large desalination facilities serving urban centers with centralized water distribution systems and power grids. While renewable energy (RE) sources could be used to serve centralized systems in urban centers and thus provide an opportunity to make desalination greener, they are mostly used to serve rural communities off of the grid. In the KSA, solar and geothermal energy are of most relevance in terms of local conditions. Our group is focusing on developing new desalination processes, adsorption desalination (AD) and membrane distillation (MD), which can be driven by waste heat, geothermal or solar energy. A demonstration solar-powered AD facility has been constructed and a life cycle assessment showed that a specific energy consumption of <1.5 kW h_e/m3 is possible. An innovative hybrid approach has also been explored which would combine solar and geothermal energy using an alternating 12-h cycle to reduce the probability of depleting the heat source within the geothermal reservoir and provide the most effective use of RE without the need for energy storage. This paper highlights the use of RE for desalination in KSA with a focus on our group\\'s contribution in developing innovative low energy-driven desalination technologies. © 2014 Elsevier Ltd. All rights reserved.

Experimental study on the self-humidification effect in proton exchange membrane fuel cells containing double gas diffusion backing layer

International Nuclear Information System (INIS)

Kong, Im Mo; Choi, Jong Won; Kim, Sung Il; Lee, Eun Sook; Kim, Min Soo

2015-01-01

Highlights: • Investigated self-humidification effect of structurally modified GDBLs in PEMFCs. • One conventional and two modified GDLs were prepared. • Structural design of the GDBLs significantly affected self-humidification. • Stacking was found to have negligible effect on self-humidification. • It can be applied readily to self-humidified PEMFCs. - Abstract: Adequate hydration of the membrane is required to ensure high proton conductivity in proton exchange membrane fuel cells (PEMFCs), which, in turn, is required for achieving high cell performances. While external humidifiers are typically used to humidify the supplied air in conventional systems, their use increases the complexity, weight, volume, and parasitic power loss in fuel cell systems, rendering them unviable in some systems, particularly for portable applications. In this study, the structure of a gas diffusion backing layer (GDBL) was modified to enhance the self-humidification effect in PEMFCs. Three types of GDLs were prepared for the experiments: a conventional GDL (GDL-A with uniform single GDBL) and two modified GDLs (GDL-A′B with uniform double GDBL and GDL-A′C with heterogeneous double GDBLs). In order to evaluate the effect of stacking and structural design on the self-humidification characteristics, some characteristics of the GDLs such as contact angle, resistance, and vapor permeation rate were measured. The electrochemical performances of the fuel cells were also measured at various relative humidity (RH) and stoichiometric ratio (SR) conditions. The results showed that stacking had a negligible effect, whereas the structural design of the GDBL had a significant effect on self-humidification. The self-humidification effect and the cell performance were improved significantly in the structurally modified GDBL. In addition, considering the actual field conditions and the results of the present study, it was concluded that the structural modifications made to the GDBL would

Desalination - A solution to water shortage

International Nuclear Information System (INIS)

Shakaib, M.

2005-01-01

Pakistan as well as neighbouring countries are faced with critical water shortage for the last few decades. The demand for water has outstripped its supply making the availability of safe water sources an issue Also conflicts over water sharing are expected in many regions of the world. Thus, because of this looming crisis water problems are getting increasing attention all over the world. With the advancement of desalination technology many countries had resorted removal of salts from brackish and sea water as an alternative water supply and they are now viewing desalination as a future solution to problems of lack of water. Today, over 100 countries use desalting requirement. A total of 12,451 desalting units (of a unit size of 100 m/sup 3//d or more) with a total capacity of 22,735,000 m /d had been installed or contracted worldwide. Brackish water desalination plants contribute with 9,400,000 m3/d, whereas the capacity of the sea water plants had reached up to 13,300,000 m3/d. This paper will discuss the use of desalination to produce potable water from saline water for domestic or municipal purposes and also the available desalination techniques that have been developed over the years and have achieved commercial success. (author)

Technology development and application of solar energy in desalination: MEDRC contribution

KAUST Repository

Ghaffour, Noreddine

2011-12-01

Desalination has become one of the sources for water supply in several countries especially in the Middle East and North Africa region. There is a great potential to develop solar desalination technologies especially in this region where solar source is abundantly available. The success in implementing solar technologies in desalination at a commercial scale depends on the improvements to convert solar energy into electrical and/or thermal energies economically as desalination processes need these types of energies. Since desalination is energy intensive, the wider use of solar technologies in desalination will eventually increase the demand on these technologies, making it possible to go for mass production of photovoltaic (PV) cells, collectors and solar thermal power plants. This would ultimately lead to the reduction in the costs of these technologies. The energy consumed by desalination processes has been significantly reduced in the last decade meaning that, if solar technologies are to be used, less PV modules and area for collectors would be needed. The main aspects to be addressed to make solar desalination a viable option in remote location applications is to develop new materials or improve existing solar collectors and find the best combinations to couple the different desalination processes with appropriate solar collector. In the objective to promote solar desalination in MENA, the Middle East Desalination Research Center has concentrated on various aspects of solar desalination in the last twelve years by sponsoring 17 research projects on different technologies and Software packages development for coupling desalination and renewable energy systems to address the limitations of solar desalination and develop new desalination technologies and hybrid systems suitable for remote areas. A brief description of some of these projects is highlighted in this paper. The full details of all these projects are available the Centers website. © 2011 Elsevier

Approach for smart application to desalination and power generation

International Nuclear Information System (INIS)

Chang Moon Hee; Kim Si-Hwan

1998-01-01

A 330 MWt integral reactor, SMART, and an integrated nuclear seawater desalination system coupled with SMART are currently under conceptual development at KAERI. The SMART will provide energy to the desalination system either in the form of heat or electricity, or both. The integrated nuclear desalination system aims to produce about 40,000 m 3 /day potable water from seawater for demonstration purposes. The remaining energy produced by SMART will be converted into electrical energy. Several important factors are especially considered in the process of SMART and its application system development. The development emphasizes the adoption of technically proven and advanced technology, measures to secure the safety and reliability of the reactor system, consideration of the desalination process for coupling with SMART, a licensing strategy for SMART and the integrated nuclear desalination system, and international cooperation for promoting nuclear desalination with the SMART development program. The current effort to establish the concept of SMART and its application for desalination is being pursued intensively to secure the safety and reliability of SMART, to prove the implemented concepts/technology considering the coupling with the desalination process, and to formulate an optimum licensing approach. This paper aims to present the technical and strategic approach of SMART and its application system. (author)

Present and future activities of nuclear desalination in Japan

International Nuclear Information System (INIS)

Minato, A.; Hirai, M.

2004-01-01

Seawater desalination plants have been installed at several nuclear power plants in Japan in order to satisfy the regulations for nuclear plant installation. This has been done where there is a limited source of water due to the geological conditions. These desalination plants are being operated to ensure supplemental water by using thermal or electrical energy from the nuclear power plant. The desalination plant is not operated continuously during the year because the major function of the plant is to ensure the supply of supplemental water for the nuclear power plant. Regarding maintenance of the desalination plant, some piping was exchanged due to corrosion by high temperature seawater, however, the desalination plants are being operated without any trouble as of today. Recently, the development of innovative and/or small reactor designs, that emphasise safety features, has been promoted in Japan to use for seawater desalination and for installation in developing countries. An advanced RO system with lower energy consumption technology is also being developed. Furthermore, some Japanese industries and universities are now very interested in nuclear desalination. (author)

Comparative study of economic competitive for nuclear seawater desalination

International Nuclear Information System (INIS)

Tian Li; Wang Yongqing

2001-01-01

The method of levelized discounted production water cost and the new desalination economic evaluation program (DEEP1.1) are used. Many cases of seawater desalination by nuclear energy or fossil energy combined with reverse osmosis (RO), Multi-effect distillation (MED) or multi-stage flash (MSF) technology in south-east Asia is performed and their economic competitive is analyzed. Their results indicate, the nuclear desalination plants have stronger economic competitive comparing to the fossil in the RO, MED and MSF technology. The desalination water cost is very changeable depending on the difference of desalination technology and water plant size. Its range is 0.56 dollar · m -3 - 1.89 dollar · m -3 , the lowest desalination water cost is product by RO and the highest is by MSF. The sensitive factors of the economic competitive are orderly the discounted rate, desalination plant size, seawater temperature and total dissolved solids (TDS), fossil fuel price and specific power plant investment. The highest rate of water cost is about 19.3% comparing to base case

Multilayer Nanoporous Graphene Membranes for Water Desalination.

Science.gov (United States)

Cohen-Tanugi, David; Lin, Li-Chiang; Grossman, Jeffrey C

2016-02-10

While single-layer nanoporous graphene (NPG) has shown promise as a reverse osmosis (RO) desalination membrane, multilayer graphene membranes can be synthesized more economically than the single-layer material. In this work, we build upon the knowledge gained to date toward single-layer graphene to explore how multilayer NPG might serve as a RO membrane in water desalination using classical molecular dynamic simulations. We show that, while multilayer NPG exhibits similarly promising desalination properties to single-layer membranes, their separation performance can be designed by manipulating various configurational variables in the multilayer case. This work establishes an atomic-level understanding of the effects of additional NPG layers, layer separation, and pore alignment on desalination performance, providing useful guidelines for the design of multilayer NPG membranes.

Coupling of AST-500 heating reactors with desalination facilities

International Nuclear Information System (INIS)

Gureyeva, L.V.; Egorov, V.V.; Podberezniy, V.L.

1997-01-01

The general issues regarding the joint operation of a NHR and a desalination facility for potable water production are briefly considered. The AST-500 reactor plant and the DOUGTPA-type evaporating desalination facilities, both relying on proven technology and solid experience of construction and operation, are taken as a basis for the design of a large-output nuclear desalination complex. Its main design characteristics are given. The similarity of NHR operation for heating grid and desalination facility in respect of reactor plant operating conditions and power regulation principles is pointed out. The issues of nuclear desalination complexes composition are discussed briefly as well. (author). 2 refs, 1 fig., 1 tab

Coupling of AST-500 heating reactors with desalination facilities

Energy Technology Data Exchange (ETDEWEB)

Gureyeva, L V; Egorov, V V [OKBM, Nizhny Novgorod (Russian Federation); Podberezniy, V L [Scientific Research Inst. of Machine Building, Ekaterinburg (Russian Federation)

1997-09-01

The general issues regarding the joint operation of a NHR and a desalination facility for potable water production are briefly considered. The AST-500 reactor plant and the DOUGTPA-type evaporating desalination facilities, both relying on proven technology and solid experience of construction and operation, are taken as a basis for the design of a large-output nuclear desalination complex. Its main design characteristics are given. The similarity of NHR operation for heating grid and desalination facility in respect of reactor plant operating conditions and power regulation principles is pointed out. The issues of nuclear desalination complexes composition are discussed briefly as well. (author). 2 refs, 1 fig., 1 tab.

Energy-positive wastewater treatment and desalination in an integrated microbial desalination cell (MDC)-microbial electrolysis cell (MEC)

Science.gov (United States)

Li, Yan; Styczynski, Jordyn; Huang, Yuankai; Xu, Zhiheng; McCutcheon, Jeffrey; Li, Baikun

2017-07-01

Simultaneous removal of nitrogen in municipal wastewater, metal in industrial wastewater and saline in seawater was achieved in an integrated microbial desalination cell-microbial electrolysis cell (MDC-MEC) system. Batch tests showed that more than 95.1% of nitrogen was oxidized by nitrification in the cathode of MDC and reduced by heterotrophic denitrification in the anode of MDC within 48 h, leading to the total nitrogen removal rate of 4.07 mg L-1 h-1. Combining of nitrogen removal and desalination in MDC effectively solved the problem of pH fluctuation in anode and cathode, and led to 63.7% of desalination. Power generation of MDC (293.7 mW m-2) was 2.9 times higher than the one without salt solution. The electric power of MDC was harvested by a capacitor circuit to supply metal reduction in a MEC, and 99.5% of lead (II) was removed within 48 h. A kinetic MDC model was developed to elucidate the correlation of voltage output and desalination efficiency. Ratio of wastewater and sea water was calculated for MDC optimal operation. Energy balance of nutrient removal, metal removal and desalination in the MDC-MEC system was positive (0.0267 kW h m-3), demonstrating the promise of utilizing low power output of MDCs.

Mechanical vapor compression Desalination plant at Trombay

International Nuclear Information System (INIS)

Adak, A.K.; Kishore, G.; Srivastava, V.K.; Tewari, P.K.

2007-01-01

Desalination plants based on Mechanical Vapour Compression (MVC) technology are inherently the most thermodynamically efficient. The thermodynamic efficiency of the MVC process is derived from the application of the heat pump principle. A single unit of two-effect MVC desalination pilot plant of capacity 50 m3/day has recently been commissioned at Trombay, Mumbai. The desalination unit is very compact and unique of its kind in the seawater desalination technologies and is being operated by using electricity only. Horizontal tube thin film spray desalination evaporators are used for efficient heat transfer. It is suitable for a site, where feed water is highly saline and condenser cooling water is absent and where a thermal heat source is not available. The unit produces high quality water, nearly demineralized (DM) quality directly from seawater. There is no need of polishing unit and product water can be utilized directly as make up of boiler feed and for other high quality process water requirements in the industries. This paper includes the design and highlights the technical features of this unit. (author)

Introduction of nuclear desalination. A guidebook

International Nuclear Information System (INIS)

2000-01-01

Interest in using nuclear energy for producing potable water has been growing worldwide in the past decade. This has been motivated by wide varieties of reasons, inter alia, from economic competitiveness of nuclear energy to energy supply diversification, from conservation of limited fossil fuel resources to environmental protection, and by nuclear technology in industrial development. IAEA feasibility studies, which have been carried out with participation of interested Member States since 1989, have shown that nuclear desalination of seawater is technically and economically viable in many water shortage regions. In view of its perspectives, several Member States have, or are planning to launch, demonstration programmes on nuclear desalination. This guidebook has been prepared for the benefit of such Member States so that the development could be facilitated as well as their resources could be shared among such interested Member States. This guidebook comprises three major parts: Part I - Overview of nuclear desalination, Part II - Special aspects and considerations relevant to the introduction of nuclear desalination, and Part III - Steps to introduce nuclear desalination. In Part I, an overview of relevant technologies and pertinent experience accumulated in the past is presented. The global situation of the freshwater problem is reviewed and incentives for utilizing nuclear energy to contribute to solving the problems are briefly set forth. State-of-the-art relevant technologies and experience with them are summarized. Part II identifies special aspects to be considered in decision making process concerning nuclear desalination. There are technical, safety and environmental and economical aspects as well as national requirements. In Part III necessary steps to be taken once nuclear desalination has been selected are elaborated. Policy issues are discussed, and project planning is summarized. This point also elaborates on project implementation aspects, which

Nuclear desalination for the northwest of Mexico

International Nuclear Information System (INIS)

Ortega C, R. F.

2008-01-01

The IMPULSA project of the Engineering Institute of UNAM, it has dedicated from the year 2005 to the study and development of new desalination technologies of seawater with renewable energies. The objective is to form a group of expert engineers and investigators in the desalination topics able to transform their scientific knowledge in engineering solutions, with a high grade of knowledge of the environment and the renewable energies. In the middle of 2007 was took the initiative in the IMPULSA project to study the nuclear desalination topic. It is evident that before the high cost of the hydrocarbons and its high environmental impact, the nuclear generation alternative of energy becomes extremely attractive, mainly for desalination projects of seawater of great size. The Northwest of Mexico is particularly attractive as the appropriate site for one nuclear desalination plant of great size given its shortage of drink water and the quick growth of its population; as well as its level of tourist, agricultural and industrial activity. In this study was revised the state of the art of the nuclear desalination on the world and it is simulated some couplings and operation forms of nuclear reactors and desalination units, from the thermodynamic and economic viewpoint with the purpose of identifying the main peculiarities of this technology. The objective of the study was to characterize several types and sizes of nuclear reactors of the last generation that could be couple to a desalination technology as multi-stage distillation, type flash distillation or inverse osmosis. It is used for this effect the DEEP 3.1 program of the IAEA to simulate the coupling and to carry out an economic preliminary evaluation. Was found cost very competitive of 0.038-0.044 US$/kWh for the electric power production and 0.60 to 0.77 US$/m 3 for the drink water produced, without including the water transport cost or the use of carbon certificates. (Author)

Nuclear desalination newsletter, No. 1, September 2009

International Nuclear Information System (INIS)

2009-09-01

This issue discusses the recent IAEA and Member States activities in the field of desalination. Reports about these activities in Algeria, China, Germany, India, Cuba, France, Indonesia, Kuwait, Libya, South Africa, Morocco, Saudi Arabia, Spain and USA are given. The new version of the DEEP software - DEEP 3.2 - is presented. A newly developed toolkit on nuclear desalination is also presented. The ongoing IAEA activities include organization and participation in meetings on nuclear desalination, or related topics, like Technical Meeting on Non Electric Applications, held in Daejeon, Rep. of Korea, 3-6 March 2009; Management of Water Use and Consumption in Water Cooled Nuclear Power; Joint ICTP/IAEA Training Workshop on Technology and Performance of Desalination Systems; Advances in Nuclear Power for Process Heat Applications. The plans for future activities and meetings are also presented

The nuclear desalination project in Morocco

International Nuclear Information System (INIS)

1996-01-01

The objectives of the seawater desalination demonstration plant in Morocco are to buildup the technical confidence in the utilization of nuclear heating reactor for seawater desalination; to establish a data base for reliable extrapolation of water production costs for a commercial nuclear plant; and to further strengthen the nuclear infrastructure in Morocco. The water production capacity of the demonstration plant would be about 8000 m 3 /d. The objectives of pre-project study are to establish a reliable basis for a decision on a nuclear desalination plant in Morocco, using a small Chinese heating reactor and to train the Morocco experts in reactor technology and licensing aspects

Desalination and nuclear energy

International Nuclear Information System (INIS)

Romeijn, A.A.

1992-01-01

The techniques for fresh water production from seawater have matured and capacities have increased considerably over the past decades. It is feasible to combine seawater desalination with the generation of electricity since power stations can provide energy and low grade heat during off peak periods for the purpose of fresh water production. A dual purpose installation, combining a seawater desalination facility with a light water reactor power generation station promises interesting possibilities. The case in South Africa, where nuclear power stations are most economically sited far from the inland coal fields, is discussed. 1 ill

Status of CEA studies on desalination on July 1, 1967

International Nuclear Information System (INIS)

Huyghe, J.; Vignet, P.; Courvoisier, P.; Frejacques, M.; Coriou, M.; Agostini, M.; Lackme, C.; CORPEL, M.; Thiriet, L.

1967-01-01

This publication contains a set of articles reporting studies on desalination performed within the CEA: preliminary draft of a desalination plant coupled with a nuclear reactor; the reverse osmosis; corrosion problems in seawater desalination plants; optimisation program of a distillation-based seawater desalination plant; activities of the department of analysis and applied chemistry in the field of desalination; abstract of a lecture on studies on price functions; studies of the department of steady isotopes on the formation of tartar depositions and their prevention; studies performed within the thermal transfer department

Dehumidification by dessiccant regenerated by natural gas at the Campeau ice rink in Gatineau; La deshumidification par dessiccant regenere par le gaz naturel a l'Arena Campeau de Gatineau

Energy Technology Data Exchange (ETDEWEB)

Lajoie, S.

2003-03-01

As air quality gains in importance, dehumidification by dessiccant represents an interesting technological solution, especially in ice rinks where bad air quality (carbon monoxide) is not unknown. Contrary to conventional technologies, dehumidification by dessiccant allows to maintain adequate levels of air quality and optimum humidity levels. Three major advantages are: improved user comfort, the building structure is protected from corrosion, and superior air quality levels are achieved. The document first provided the reader with a brief overview of conventional mechanical dehumidification systems before discussing dehumidification by natural gas dessiccant. A quick historical review of the Campeau ice rink in Gatineau, Quebec was provided, including results obtained. The article concluded by indicating that the technology offers interesting potential for ice rinks. Energy savings are made possible through the utilization of this technology, and improves revenues by stretching operations for longer periods. 1 tab., 1 fig.

Improving environmental performance of post-harvest supply chains of fruits and vegetables in Europe: Potential contribution from ultrasonic humidification

DEFF Research Database (Denmark)

Fabbri, Serena; Olsen, Stig Irving; Owsianiak, Mikołaj

2018-01-01

Post-harvest losses of fruits and vegetables during refrigerated storage, transportation and retail are an important contributor to total environmental impacts of food supply chains in Europe. Ultrasonic humidification can reduce these post-harvest losses, but it is currently unknown whether...... that humidification may be an attractive technology for making supply chain management more sustainable....... implementing the technology in practice improves the environmental performance of the supply chains. Here, using life cycle assessment we showed that ultrasonic humidification has the potential to reduce environmental impacts, including climate change impacts, of selected fruits and vegetables in Europe by up...

Functional short- and long-term effects of nasal CPAP with and without humidification on the ciliary function of the nasal respiratory epithelium.

Science.gov (United States)

Sommer, J Ulrich; Kraus, Marius; Birk, Richard; Schultz, Johannes D; Hörmann, Karl; Stuck, Boris A

2014-03-01

Continuous positive airway pressure (CPAP) is the gold standard in the treatment of obstructive sleep apnea (OSA), but its impact on ciliary function is unclear to date. Furthermore, CPAP is associated with numerous side effects related to the nose and upper airway. Humidified CPAP is used to relieve these symptoms, but again, little is known regarding its effect on ciliary function of the nasal respiratory epithelium. In this prospective, randomized, crossover trial, 31 patients with OSA (AHI >15/h) were randomized to two treatment arms: nasal continuous positive airway pressure (nCPAP) with humidification or nCPAP without humidification for one night in each modality to assess short-term effects of ciliary beat frequency (CBF) and mucus transport time (MTT) and consecutively for 8 weeks in each modality to assess long-term effects in a crossover fashion. The baseline CBF was 4.8 ± 0.6 Hz, and baseline MTT was 540 ± 221 s. After one night of CPAP with and without humidification, ciliary function increased moderately yet with statistical significance (p humidification did not differ statistically significant. Regarding long-term effects of CPAP, a statistically significant increase in ciliary function above the baseline level and above the short-term level was shown without humidification (7.2 ± 0.4 Hz; 402 ± 176 s; p humidification (9.3 ± 0.7 Hz; 313 ± 95 s; p humidification, nCPAP has moderate effects on short-term ciliary function of the nasal respiratory epithelium. However, a significant increase in ciliary function-both in terms of an increased CBF and a decreased MTT-was detected after long-term use. The effect was more pronounced when humidification was used during nCPAP.

NDDP multi-stage flash desalination process simulator design

International Nuclear Information System (INIS)

Chatterjee, M.; Sashi Kumar, G.N.; Mahendra, A.K.; Sanyal, A.; Gouthaman, G.

2006-05-01

A majority of large-scale desalination plants all over the world employ multi-stage flash (MSF) distillation process. Many of these MSF desalination plants have been set up near to nuclear power plants (generally called as nuclear desalination plants) to effectively utilize the low-grade steam from the power plants as the source of energy. A computer program called MSFSIM has been developed to simulate the MSF desalination plant operation both for steady state and various transients including start up. This code predicts the effect of number of stages, flashing temperature, velocity of brine flowing through the tubes of brine heater and evaporators, temperature of the condensing thin film etc. on the plant performance ratio. Such a code can be used for the design of a new plant and to predict its operating and startup characteristics. The code has been extensively validated with available start up data from the pilot MSF desalination plant of 425-m3/day capacity at Trombay, Mumbai. A MSF desalination plant of 4500-m3/day capacity is under construction by BARC at Kalpakkam, which will utilize the steam from Madras Atomic Power Station (MAPS). In this present work extensive parametric study of the 4500-m3/day capacity desalination plant at Kalpakkam has been done using the code MSFSIM for optimizing the operating parameters in order to maximize the performance ratio for stable plant operation. The aim of the work is prediction of plant performance under different operating conditions. (author)

Process technologies for water desalination

International Nuclear Information System (INIS)

Ramilo, Lucia B.; Gomez de Soler, Susana M.; Coppari, Norberto R.

2003-01-01

The use of the nuclear energy for simultaneous electricity and potable water production is an attractive, technically feasible and safe alternative to fossil energy options. In Argentina the nuclear desalination option is being studied together with the alternative uses of the innovative advanced Argentinean CAREM reactor, in a research contract between CNEA and the IAEA to evaluate projects of nuclear desalination. This paper analyses the benefits and drawbacks of each desalination technology, the distinctive characteristics of the technology that fit better the different uses, and outlines the related antecedents of its application in the world. In this report a summarized description of those technologies is included by way of introduction, so as to highlight the main advantages and disadvantages of each of them. The improvements and innovations made in the last years for the different technologies are also described. (author)

Evaluation of the Performance of Houses With and Without Supplemental Dehumidification in a Hot-Humid Climate

Energy Technology Data Exchange (ETDEWEB)

Kerrigan, P.; Norton, P.

2014-10-01

This report, Evaluation of the Performance of Houses with and without Supplemental Dehumidification in a Hot-Humid Climate, describes a research study that that was conducted by the Building Science Corporation (BSC) Building America Research Team. BSC seeks to research and report on the field monitoring of the performance of in-situ supplemental dehumidification systems in low energy, high performance, homes in a Hot-Humid climate. The purpose of this research project was to observe and compare the humidity control performance of new, single family, low energy, and high performance, homes. Specifically, the study sought to compare the interior conditions and mechanical systems operation between two distinct groups of houses, homes with a supplemental dehumidifier installed in addition to HVAC system, and homes without any supplemental dehumidification. The subjects of the study were ten single-family new construction homes in New Orleans, LA.Data logging equipment was installed at each home in 2012. Interior conditions and various end-use loads were monitored for one year. In terms of averages, the homes with dehumidifiers are limiting elevated levels of humidity in the living space. However, there was significant variation in humidity control between individual houses. An analysis of the equipment operation did not show a clear correlation between energy use and humidity levels. In general, no single explanatory variable appears to provide a consistent understanding of the humidity control in each house. Indoor humidity is likely due to all of the factors we have examined, and the specifics of how they are used by each occupant.

Sea water desalination by horizontal tubes evaporator

International Nuclear Information System (INIS)

Mohammadi, H.K.; Mohit, M.

1986-01-01

Desalinated water supplies are one of the problems of the nuclear power plants located by the seas. This paper explains saline water desalination by a Horizontal Tube Evaporator (HTE) and compares it with flash evaporation. A thermo compressor research project using HTE method has been designed, constructed, and operated at the Esfahan Nuclear Technology Center ENTC. The poject's ultimate goal is to obtain empirical formulae based on data gathered during operation of the unit and its subsequent development towards design and construction of desalination plants on an industrial scale

Humidification mitigates acute mucosal toxicity during radiotherapy when factoring volumetric parameters. Trans Tasman Radiation Oncology Group (TROG) RadioHUM 07.03 substudy.

Science.gov (United States)

Macann, A; Fauzi, F; Simpson, J; Sasso, G; Krawitz, H; Fraser-Browne, C; Manitz, J; Raith, A

2017-12-01

To model in a subset of patients from TROG 07.03 managed at a single site the association between domiciliary based humidification use and mucositis symptom burden during radiotherapy (RT) for head and neck cancer (HNC) when factoring in volumetric radiotherapy parameters derived from tumour and normal tissue regions of interest. From June 2008 through June 2011, 210 patients with HNC receiving RT were randomised to either a control arm or humidification using the Fisher & Paykel Healthcare MR880 humidifier. This subset analysis involves patients recruited from Auckland City Hospital treated with a prescribed dose of ≥70 Gy. Regression models included control variables for Planning Target Volume 70 GY (PTV70Gy); Equivalent Uniform Dose (EUD) MOIST and TSV (surrogates of total mucosal and total swallowing volumes respectively). The analysis included 39 patients (humidification 20, control 19). There was a significant odds reduction in CTCAE v3.0 functional mucositis score of 0.29 associated with the use of humidification (pfactor of 11.11 for humidification patients (p=.013). The results support the hypothesis that humidification can help mitigate mucositis symptom burden. Radiotherapy dosimetric parameters assist in the evaluation of toxicity interventions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Randomized controlled trial on postoperative pulmonary humidification after total laryngectomy: external humidifier versus heat and moisture exchanger.

Science.gov (United States)

Mérol, Jean-Claude; Charpiot, Anne; Langagne, Thibault; Hémar, Patrick; Ackerstaff, Annemieke H; Hilgers, Frans J M

2012-02-01

Assessment of immediate postoperative airway humidification after total laryngectomy (TLE), comparing the use of an external humidifier (EH) with humidification through a heat and moisture exchanger (HME). Randomized controlled trial (RCT). Fifty-three patients were randomized into the standard (control) EH (N = 26) or the experimental HME arm (N = 27). Compliance, pulmonary and sleeping problems, patients' and nursing staff satisfaction, nursing time, and cost-effectiveness were assessed with trial-specific structured questionnaires and tally sheets. In the EH arm data were available for all patients, whereas in the HME arm data were incomplete for four patients. The 24/7 compliance rate in the EH arm was 12% and in the HME arm 87% (77% if the four nonevaluable patients are considered noncompliant). Compliance and patients' satisfaction were significantly better, and the number of coughing episodes, mucus expectoration for clearing the trachea, and sleeping disturbances were significantly less in the HME arm (P humidification by means of an HME over the use of an EH after TLE. This study therefore underlines that HMEs presently can be considered the better option for early postoperative airway humidification after TLE. Copyright © 2011 The American Laryngological, Rhinological, and Otological Society, Inc.

Corrosion and Protection of Metal in the Seawater Desalination

Science.gov (United States)

Hou, Xiangyu; Gao, Lili; Cui, Zhendong; Yin, Jianhua

2018-01-01

Seawater desalination develops rapid for it can solve water scarcity efficiently. However, corrosion problem in the seawater desalination system is more serious than that in normal water. So, it is important to pay attention to the corrosion and protection of metal in seawater desalination. The corrosion characteristics and corrosion types of metal in the seawater desalination system are introduced in this paper; In addition, corrosion protect methods and main influencing factors are stated, the latest new technologies about anti-corrosion with quantum energy assisted and magnetic inhibitor are presented.

Desalination of seawater with nuclear power reactors in cogeneration

International Nuclear Information System (INIS)

Flores E, R.M.

2004-01-01

The growing demand for energy and hydraulic resources for satisfy the domestic, industrial, agricultural activities, etc. has wakened up the interest to carry out concerning investigations to study the diverse technologies guided to increase the available hydraulic resources, as well as to the search of alternatives of electric power generation, economic and socially profitable. In this sense the possible use of the nuclear energy is examined in cogeneration to obtain electricity and drinkable water for desalination of seawater. The technologies are analysed involved in the nuclear cogeneration (desalination technology, nuclear and desalination-nuclear joining) available in the world. At the same time it is exemplified the coupling of a nuclear reactor and a process of hybrid desalination that today in day the adult offers and economic advantages. Finally, the nuclear desalination is presented as a technical and economically viable solution in regions where necessities of drinkable water are had for the urban, agricultural consumption and industrial in great scale and that for local situations it is possible to satisfy it desalinating seawater. (Author)

Seawater desalination using an advanced small integral reactor - SMART

International Nuclear Information System (INIS)

Hwang, Young Dong; Chang, Moon Hee; Lee, Man Ki

1999-01-01

A concept of a dual-purpose integrated nuclear desalination plant coupled with the advanced small integral reactor SMART was established. The design concept of the plant aims to produce 40,000m 5 /day of water with the MED process and to generate about 90 MWe of electricity. In order to examine the technical, economic, and safety considerations in coupling SMART with desalination, a preliminary analysis on water production costs and a safety review of potential disturbances of the integrated nuclear desalination plant have been performed. The results of economic evaluation show that the use of SMART for seawater desalination is either comparative to or more economical, with respect to the water production cost, than the use of fossil fuels in comparison with the data published by the IAEA. It was also found that any possible transient event of the desalination plant does not impact on the reactor safety. The key safety parameters of the transient events induced by the potential disturbances of the desalination plant are bounded by the limits of safety analysis of SMART

Regulatory requirements for desalination plant coupled with nuclear reactor plant

International Nuclear Information System (INIS)

Yune, Young Gill; Kim, Woong Sik; Jo, Jong Chull; Kim, Hho Jung; Song, Jae Myung

2005-01-01

A small-to-medium sized reactor has been developed for multi-purposes such as seawater desalination, ship propulsion, and district heating since early 1990s in Korea. Now, the construction of its scaled-down research reactor, equipped with a seawater desalination plant, is planned to demonstrate the safety and performance of the design of the multi-purpose reactor. And the licensing application of the research reactor is expected in the near future. Therefore, a development of regulatory requirements/guides for a desalination plant coupled with a nuclear reactor plant is necessary for the preparation of the forthcoming licensing review of the research reactor. In this paper, the following contents are presented: the design of the desalination plant, domestic and foreign regulatory requirements relevant to desalination plants, and a draft of regulatory requirements/guides for a desalination plant coupled with a nuclear reactor plant

Humidification of incubators.

Science.gov (United States)

Harpin, V A; Rutter, N

1985-01-01

The effect of increasing the humidity in incubators was examined in 62 infants of less than 30 weeks' gestation. Thirty three infants nursed in high humidity for two weeks were compared retrospectively with 29 infants from an earlier study who were nursed under plastic bubble blankets or with topical paraffin but without raised humidity. Humidification reduced skin water loss and improved maintenance of body temperature from birth, but did not delay the normal postnatal maturation of the skin. Infants nursed without humidity frequently became hypothermic in spite of a high incubator air temperature. These advantages must be weighed against the finding that overheating was more common and Pseudomonas was more commonly isolated from the infants. It is recommended that incubator humidity is raised for babies under 30 weeks' gestation in the first days of life but meticulous attention should be paid to fluid balance, avoiding overheating, and cleansing of the humidifier reservoir. PMID:3985653

Process technologies for water desalination

International Nuclear Information System (INIS)

Ramilo, Lucia B.; Gomez de Soler, Susana M.; Coppari, Norberto R.

2003-01-01

The use of the nuclear energy for simultaneous electricity and potable water production is an attractive, technically feasible, and safe alternative to fossil energy options. In Argentina the nuclear desalination option is being studied together with the alternative uses of the innovative advanced Argentinean CAREM reactor, in the research contract CNEA - IAEA to evaluate projects of nuclear desalination. The objective and scope of this work is to know the advantages and disadvantages of each desalination technology, distinctive characteristics of each of them, that make them adapt better to different uses and outline conditions and analysis of related antecedents of its use in the world. In this report a summarized description of those technologies is included by way of introduction, so as to highlight the main advantages and disadvantages of each of them. The improvements and innovations found in the last years for the different technologies are also included. (author)

The cost of nuclear desalination

International Nuclear Information System (INIS)

1966-01-01

Full text: What would be the cost of fresh water obtained by desalination of sea or brackish water with the help of a nuclear reactor? What methods are being employed for such costing and evaluation? These are basic questions for the increasing number of countries which are considering water desalination for the production of drinking water or for industrial or agricultural purposes. Following the recommendations of a panel of experts convened by the IAEA in Vienna, Austria, in April 1965, the Agency is now preparing a report on the desalination methods used or developed in various countries. Another panel met in Vienna in April of the current year, to help the Agency with the final draft of this report which is due to be published this autumn. The panel, 20 experts from 7 countries, was chaired consecutively by Mr. N. Carrillo (Mexico) and Mr. V.N. Meckoni (India). (author)

Impact of heated humidification with automatic positive airway pressure in obstructive sleep apnea therapy.

Science.gov (United States)

Salgado, Sara Moreira da Silva Trindade; Boléo-Tomé, José Pedro Correia Fernandes; Canhão, Cristina Maria Sardinha; Dias, Ana Rita Tavares; Teixeira, Joana Isaac; Pinto, Paula Maria Gonçalves; Caetano, Maria Cristina de Brito Eusébio Bárbara Prista

2008-09-01

To study the impact that heated humidification instituted in the beginning of automatic positive airway pressure (APAP) therapy has on compliance with and the side effects of the treatment. Thirty-nine treatment-naïve patients with obstructive sleep apnea were randomized into two groups to receive APAP using one of two modalities: with heated humidification (APAPwith group); and without heated humidification (APAPw/o group).Patients were evaluated at 7 and 30 days after APAP initiation. The following parameters were analyzed: compliance with treatment (mean number of hours/night); side effects (dry nose or mouth, nasal obstruction and rhinorrhea); daytime sleepiness (Epworth sleepiness scale score) and subjective comfort (visual analog scale score). Patients were also evaluated in terms of residual apnea-hypopnea index (AHI), as well as mean pressures and leaks registered in the ventilators. There were no differences between the two groups in terms of mean age (APAPwith: 57.4 +/- 9.2; APAPw/o: 56.5 +/- 10.7 years), AHI (APAPwith: 28.1 +/- 14.0; APAPw/o: 28.8 +/- 20.5 events/hour of sleep), baseline Epworth score (APAPwith: 11.2 +/- 5.8; APAPw/o: 11.9 +/- 6.3) and initial nasal symptoms. Compliance was similar in both groups (APAPwith: 5.3 +/- 2.4; APAPw/o: 5.2 +/- 2.3 h/night). There were no differences in any of the other parameters analyzed. The introduction of heated humidification at the beginning of APAP therapy provided no advantage in terms of treatment compliance or side effects of treatment.

A floating desalination/co-generation system using the KLT-40 reactor and Canadian RO desalination technology

International Nuclear Information System (INIS)

Humphries, J.R.; Davies, K.

2000-01-01

As the global consumption of water increases with growing populations and rising levels of industrialization, major new sources of potable water production must be developed. To address this issue efficiently and economically, a new approach has been developed in Canada for the integration of reverse osmosis (RO) desalination systems with nuclear reactors as an energy source. The resulting nuclear desalination/cogeneration plant makes use of waste heat from the electrical generation process to preheat the RO feedwater, advanced feedwater pre-treatment and sophisticated system design integration and optimization techniques. These innovations have led to improved water production efficiency, lower water production costs and reduced environmental impact. The Russian Federation is developing the KLT-40 reactor for application as a Floating Power Unit (FPU). The reactor is ideally suited for such purposes, having bad many years of successful operation as a marine propulsion reactor aboard floating nuclear powered icebreakers and other nuclear propelled vessels. Under the terms of a cooperation agreement with the Russian Federation Ministry of Atomic Energy, CANDESAL Enterprises Ltd has evaluated the FPU, containing two KLT-40 reactors, as a source of electrical energy and waste heat for RO desalination. A design concept for a floating nuclear desalination complex consisting of the FPU and a barge mounted RO desalination unit has been analyzed to establish preliminary performance characteristics for the complex. The FPU, operating as a barge mounted electrical generating station, provides electricity to the desalination barge. In addition, the condenser cooling water from the FPU is used as a source of preheated feedwater for the RO system on the desalination barge. The waste heat produced by the electrical generating process is sufficient to provide RO feedwater at a temperature of about 10 deg. C above ambient seawater temperature. Preliminary design studies have

Nuclear Desalination Demonstration Project (NDDP) in India

International Nuclear Information System (INIS)

Tewari, P.K.; Misra, B.M.

2001-01-01

In order to gainfully employ the years of experience and expertise in various aspects of desalination activity, BARC (India) has undertaken installation of a hybrid nuclear desalination plant coupled to 170 MW(e) PHWR station at Kalpakkam, Chennai in the Southeast coast of India. The integrated system, called the Nuclear Desalination Demonstration Project (NDDP), will thus meet the dual needs of process water for nuclear power plant and drinking water for the neighbouring people. NDDP aims for demonstrating the safe and economic production of good quality water by nuclear desalination of seawater. It comprises a 4500 m 3 /d Multistage Flash (MSF) and a 1800 m 3 /d Reverse Osmosis (RO) plant. MSF section uses low pressure steam from Madras Atomic Power Station (MAPS), Kalpakkam. The objectives of the NDDP (Kalpakkam) are as follows: to establish the indigenous capability for the design, manufacture, installation and operation of nuclear desalination plants; to generate necessary design inputs and optimum process parameters for large scale nuclear desalination plant; to serve as a demonstration project to IAEA welcoming participation from interested member states. The hybrid plant is envisaged to have a number of advantages: a part of high purity desalted water produced from MSF plant will be used for the makeup demineralised water requirement (after necessary polishing) for the power station; blending of the product water from RO and MSF plants would provide requisite quality drinking water; the RO plant will continue to be operated to provide the water for drinking purposes during the shutdown of the power station

Humidification performance of 48 passive airway humidifiers: comparison with manufacturer data.

Science.gov (United States)

Lellouche, François; Taillé, Solenne; Lefrançois, Frédéric; Deye, Nicolas; Maggiore, Salvatore Maurizio; Jouvet, Philippe; Ricard, Jean-Damien; Fumagalli, Bruno; Brochard, Laurent

2009-02-01

Heat and moisture exchangers (HMEs) are increasingly used in the ICU for gas conditioning during mechanical ventilation. Independent assessments of the humidification performance of HMEs are scarce. The aim of the present study was thus to assess the humidification performance of a large number of adult HMEs. We assessed 48 devices using a bench test apparatus that simulated real-life physiologic ventilation conditions. Thirty-two devices were described by the manufacturers as HMEs, and 16 were described as antibacterial filters. The test apparatus provided expiratory gases with an absolute humidity (AH) of 35 mg H(2)O/L. The AH of inspired gases was measured after steady state using the psychrometric method. We performed three hygrometric measurements for each device, measured their resistance, and compared our results with the manufacturer data. Of the 32 HMEs tested, only 37.5% performed well (>or= 30 mg H(2)O/L), while 25% performed poorly ( 4 mg H(2)O/L. The mean difference for the antibacterial filters was 0.2 +/- 1.4 mg H(2)O/L. The mean resistance of all the tested devices was 2.17 +/- 0.70 cm H(2)O/L/s. Several HMEs performed poorly and should not be used as HMEs. The values determined by independent assessments may be lower than the manufacturer data. Describing a device as an HME does not guarantee that it provides adequate humidification. The performance of HMEs must be verified by independent assessment.

A change in humidification system can eliminate endotracheal tube occlusion.

Science.gov (United States)

Doyle, Alex; Joshi, Manasi; Frank, Peter; Craven, Thomas; Moondi, Parvez; Young, Peter

2011-12-01

Inadequate airway humidification can result in endotracheal tube occlusion. There is evidence that heat and moisture exchangers (HMEs) are more prone to endotracheal tube occlusion than heated humidifiers (HHs) that contain a heated wire circuit. We aimed to compare the incidence of endotracheal tube occlusion while introducing a new dual-heated wire circuit HH in place of an established hydrophobic HME. This was a prospective observational study. All patients who required intubation were included in our analysis. Univariate statistical analysis was performed using a Fisher exact test. P humidification exclusively by HH. In the subsequent 18-month period, there were no further episodes of endotracheal tube occlusion. Our study demonstrates that there is a significant increase in the incidence of endotracheal tube occlusion when using a hydrophobic HME compared with an HH and that using a dual-heated wire circuit HH can eliminate endotracheal tube occlusion. Copyright © 2011 Elsevier Inc. All rights reserved.

Prospects of solar desalination in Pakistan

Energy Technology Data Exchange (ETDEWEB)

Saif-ur-Rehman, M; Bhatti, M R; Malik, M A

1973-01-01

This paper deals with the present state-of-the-art of solar desalination and evaluates the possibility of using solar stills in Pakistan. Along with the world survey of solar desalination units a brief description of the process and solar still is described. The areas of prospective users, i.e., having acute shortage of freshwater, even for drinking, are outlined.

Experience with nuclear desalination in Japan

International Nuclear Information System (INIS)

Shiota, Y.

1996-01-01

In Japan, the seawater desalination facilities were used mainly for potable water in remote islands and industrial water such as boiler feedwater. In order to produce potable water, distillation processes, Electrical Dialysis (ED) and Reverse Osmosis (RO) were used in the past. The distillation facilities were used to produce boiler feedwater, however, RO facilities are now used for this purpose, such as the nuclear desalination facilities with capacities of 2600 m 3 /d, 2000 m 3 /d and 1000 m 3 /d, in Kansai Electric Power Co., Ltd., Shikoku Electric Power Co., Inc. and Kyuhshu Electric Power Co., Inc., respectively. The RO process is becoming a main stream of desalination because the process has a low energy consumption. 6 tabs

Why do local communities support or oppose seawater desalination?

Science.gov (United States)

Mirza Ordshahi, B.; Heck, N.; Faraola, S.; Paytan, A.; Haddad, B.; Potts, D. C.

2016-12-01

Freshwater shortages have become a global problem due to increasing water consumption and environmental changes which are reducing the reliability of traditional water resources. One option to address water shortages in coastal areas is the use of seawater desalination. Desalination technology is particularly valued for the production of high quality drinking water and consistent production. However, seawater desalination is controversial due to potential environmental, economic, and societal impacts and lack of public support for this water supply method. Compared to alternative potable water production methods, such as water recycling, little is known about public attitudes towards seawater desalination and factors that shape local support or rejection. Our research addresses this gap and explores variables that influence support for proposed desalination plants in the Monterey Bay region, where multiple facilities have been proposed in recent years. Data was collected via a questionnaire-based survey among a random sample of coastal residents and marine stakeholders between June-July, 2016. Findings of the study identify the influence of socio-demographic variables, knowledge about desalination, engagement in marine activities, perception of the environmental context, and the existence of a National Marine Sanctuary on local support. Research outcome provide novel insights into public attitudes towards desalination and enhances our understanding of why communities might support or reject this water supply technology.

Improvement of water desalination technologies in reverse osmosis plants

Science.gov (United States)

Vysotskii, S. P.; Konoval'chik, M. V.; Gul'ko, S. E.

2017-07-01

The strengthening of requirements for the protection of surface-water sources and increases in the cost of reagents lead to the necessity of using membrane (especially, reverse osmosis) technologies of water desalination as an alternative to ion-exchange technologies. The peculiarities of using reverse osmosis technologies in the desalination of waters with an increased salinity have been discussed. An analogy has been made between the dependence of the adsorptive capacity of ion-exchange resins on the reagent consumption during ion exchange and the dependence of the specific ion flux on the voltage in the electrodialysis and productivity of membrane elements on the excess of the pressure of source water over the osmotic pressure in reverse osmosis. It has been proposed to regulate the number of water desalination steps in reverse osmosis plants, which makes it possible to flexibly change the productivity of equipment and the level of desalinization, depending on the requirements for the technological process. It is shown that the selectivity of reverse osmotic membranes with respect to bivalent ions (calcium, magnesium, and sulfates) is approximately four times higher than the selectivity with respect to monovalent ions (sodium and chlorine). The process of desalination in reverse osmosis plants depends on operation factors, such as the salt content and ion composition of source water, the salt content of the concentrate, and the temperatures of solution and operating pressure, and the design features of devices, such as the length of the motion of the desalination water flux, the distance between membranes, and types of membranes and turbulators (spacers). To assess the influence of separate parameters on the process of reverse osmosis desalination of water solutions, we derived criteria equations by compiling problem solution matrices on the basis of the dimensional method, taking into account the Huntley complement. The operation of membrane elements was

An exergy approach to efficiency evaluation of desalination

KAUST Repository

Ng, Kim Choon

2017-05-02

This paper presents an evaluation process efficiency based on the consumption of primary energy for all types of practical desalination methods available hitherto. The conventional performance ratio has, thus far, been defined with respect to the consumption of derived energy, such as the electricity or steam, which are susceptible to the conversion losses of power plants and boilers that burned the input primary fuels. As derived energies are usually expressed by the units, either kWh or Joules, these units cannot differentiate the grade of energy supplied to the processes accurately. In this paper, the specific energy consumption is revisited for the efficacy of all large-scale desalination plants. In today\\'s combined production of electricity and desalinated water, accomplished with advanced cogeneration concept, the input exergy of fuels is utilized optimally and efficiently in a temperature cascaded manner. By discerning the exergy destruction successively in the turbines and desalination processes, the relative contribution of primary energy to the processes can be accurately apportioned to the input primary energy. Although efficiency is not a law of thermodynamics, however, a common platform for expressing the figures of merit explicit to the efficacy of desalination processes can be developed meaningfully that has the thermodynamic rigor up to the ideal or thermodynamic limit of seawater desalination for all scientists and engineers to aspire to.

Influence of fuel costs on seawater desalination options

International Nuclear Information System (INIS)

Methnani, Mabrouk

2007-01-01

Reference estimates of seawater desalination costs for recent mega projects are all quoted in the range of US$0.50/m 3 . This however does not reflect the recent trends of escalating fossil fuel costs. In order to analyze the effect of these trends, a recently updated version of the IAEA Desalination Economic Evaluation Program, DEEP-3, has been used to compare fossil and nuclear seawater desalination options, under varied fuel cost and interest rate scenarios. Results presented for a gas combined-cycle and a modular high-temperature gas-cooled reactor design, show clear cost advantages for the latter, for both Multi-Effect Distillation (MED) and Reverse Osmosis (RO). Water production cost estimates for the Brayton cycle nuclear option are hardly affected by fuel costs, while combined cycle seawater desalination costs show an increase of more than 40% when fuel costs are doubled. For all cases run, the nuclear desalination costs are lower and if the current trend in fossil fuel prices continues as predicted by pessimist scenarios and the carbon tax carried by greenhouse emissions is enforced in the future, the cost advantage for nuclear desalination will be even more pronounced. Increasing the interest rate from 5 to 8% has a smaller effect than fuel cost variations. It translates into a water cost increase in the range of 10-20%, with the nuclear option being the more sensitive. (author)

An exergy approach to efficiency evaluation of desalination

Science.gov (United States)

Ng, Kim Choon; Shahzad, Muhammad Wakil; Son, Hyuk Soo; Hamed, Osman A.

2017-05-01

This paper presents an evaluation process efficiency based on the consumption of primary energy for all types of practical desalination methods available hitherto. The conventional performance ratio has, thus far, been defined with respect to the consumption of derived energy, such as the electricity or steam, which are susceptible to the conversion losses of power plants and boilers that burned the input primary fuels. As derived energies are usually expressed by the units, either kWh or Joules, these units cannot differentiate the grade of energy supplied to the processes accurately. In this paper, the specific energy consumption is revisited for the efficacy of all large-scale desalination plants. In today's combined production of electricity and desalinated water, accomplished with advanced cogeneration concept, the input exergy of fuels is utilized optimally and efficiently in a temperature cascaded manner. By discerning the exergy destruction successively in the turbines and desalination processes, the relative contribution of primary energy to the processes can be accurately apportioned to the input primary energy. Although efficiency is not a law of thermodynamics, however, a common platform for expressing the figures of merit explicit to the efficacy of desalination processes can be developed meaningfully that has the thermodynamic rigor up to the ideal or thermodynamic limit of seawater desalination for all scientists and engineers to aspire to.

Rotating carbon nanotube membrane filter for water desalination

Science.gov (United States)

Tu, Qingsong; Yang, Qiang; Wang, Hualin; Li, Shaofan

2016-01-01

We have designed a porous nanofluidic desalination device, a rotating carbon nanotube membrane filter (RCNT-MF), for the reverse osmosis desalination that can turn salt water into fresh water. The concept as well as design strategy of RCNT-MF is modeled, and demonstrated by using molecular dynamics simulation. It has been shown that the RCNT-MF device may significantly improve desalination efficiency by combining the centrifugal force propelled reverse osmosis process and the porous CNT-based fine scale selective separation technology. PMID:27188982

Development of an Air-Source Heat Pump Integrated with a Water Heating / Dehumidification Module

Energy Technology Data Exchange (ETDEWEB)

Rice, C Keith [ORNL; Uselton, Robert B. [Lennox Industries, Inc; Shen, Bo [ORNL; Baxter, Van D [ORNL; Shrestha, Som S [ORNL

2014-01-01

A residential-sized dual air-source integrated heat pump (AS-IHP) concept is under development in partnership between ORNL and a manufacturer. The concept design consists of a two-stage air-source heat pump (ASHP) coupled on the air distribution side with a separate novel water heating/dehumidification (WH/DH) module. The motivation for this unusual equipment combination is the forecast trend for home sensible loads to be reduced more than latent loads. Integration of water heating with a space dehumidification cycle addresses humidity control while performing double-duty. This approach can be applied to retrofit/upgrade applications as well as new construction. A WH/DH module capable of ~1.47 L/h water removal and ~2 kW water heating capacity was assembled by the manufacturer. A heat pump system model was used to guide the controls design; lab testing was conducted and used to calibrate the models. Performance maps were generated and used in a TRNSYS sub-hourly simulation to predict annual performance in a well-insulated house. Annual HVAC/WH energy savings of ~35% are predicted in cold and hot-humid U.S. climates compared to a minimum efficiency baseline.

Active versus passive humidification for self-ventilating tracheostomy and laryngectomy patients: a systematic review of the literature.

Science.gov (United States)

Wong, C Y Y; Shakir, A A; Farboud, A; Whittet, H B

2016-12-01

To determine whether active or passive humidification methods are more effective in preventing pulmonary complications in self-ventilating neck breather patients. Systematic Review adhering to PRISMA guidance (checklist sourced from www.equator-network.org/). Review of current published relevant literature at a tertiary department of Otolaryngology and Head & Neck Surgery. We included all separate studies and comparison studies of active and passive humidification techniques in adult and paediatric neck breather patients. The primary outcome is the reduction in pulmonary complications. Secondary outcomes include patient compliance; carer and user satisfaction. Seven studies were included in this review: two RCTs (133 patients), one randomised controlled cross-over trial (29 patients), three randomised prospective studies (171 patients), and one retrospective study (73 patients). Only one study was conducted on paediatric neck breathers. The overall quality of the studies was low. Five studies were at a high risk of bias. Of the remaining two studies, one study had a low risk of bias and the other had an unclear risk. Despite limited subject evidence, results show that passive methods of humidification (mainly HME) is the preferred choice of humidification in the spontaneously breathing neck breather patients group mainly due to the reduction in pulmonary complaints, and better patient compliance. © 2015 John Wiley & Sons Ltd.

RO-PRO desalination: An integrated low-energy approach to seawater desalination

International Nuclear Information System (INIS)

Prante, Jeri L.; Ruskowitz, Jeffrey A.; Childress, Amy E.; Achilli, Andrea

2014-01-01

Highlights: • In the novel RO-PRO system, the energy produced by PRO is utilized to offset the energy consumed by the RO. • The specific energy consumption of a RO-PRO system was modeled for the first time. • A novel module-based PRO model for full-scale applications was developed. • The minimum net specific energy consumption of the modeled RO-PRO system was 1.2 kW h/m 3 at 50% RO recovery. • A sensitivity analysis showed a min RO-PRO specific energy consumption of 1.0 kW h/m 3 and a max power density of 10 W/m 2 . - Abstract: Although reverse osmosis (RO) is currently the most energy efficient desalination technology, it still requires a great deal of energy to create the high pressures necessary to desalinate seawater. An opposite process of RO, called pressure retarded osmosis (PRO), utilizes the salinity gradient between a relatively fresh impaired water source and seawater to produce pressure and hence, energy. In this paper, PRO is evaluated in conjunction with RO, in a system called RO-PRO desalination, to reduce the energy requirement of seawater RO desalination. RO-PRO specific energy consumption was modeled using RO conditions at the thermodynamic restriction and a newly developed module-based PRO model. Using a well-characterized cellulose triacetate (CTA) membrane, the minimum net specific energy consumption of the system was found to be approximately 40% lower than state-of-the-art seawater RO. A sensitivity analysis was performed to determine the effects of membrane characteristics on the specific energy production of the PRO process in the RO-PRO system. The sensitivity analysis showed that the minimum specific energy consumption using virtual membranes is approximately 1.0 kW h per m 3 of RO permeate at 50% RO recovery and that a maximum power density of approximately 10 W/m 2 could be achieved

Low Energy Desalination Using Battery Electrode Deionization

KAUST Repository

Kim, Taeyoung

2017-09-21

New electrochemical technologies that use capacitive or battery electrodes are being developed to minimize energy requirements for desalinating brackish waters. When a pair of electrodes is charged in capacitive deionization (CDI) systems, cations bind to the cathode and anions bind to the anode, but high applied voltages (>1.2 V) result in parasitic reactions and irreversible electrode oxidation. In the battery electrode deionization (BDI) system developed here, two identical copper hexacyanoferrate (CuHCF) battery electrodes were used that release and bind cations, with anion separation occurring via an anion exchange membrane. The system used an applied voltage of 0.6 V, which avoided parasitic reactions, achieved high electrode desalination capacities (up to 100 mg-NaCl/g-electrode, 50 mM NaCl influent), and consumed less energy than CDI. Simultaneous production of desalinated and concentrated solutions in two channels avoided a two-cycle approach needed for CDI. Stacking additional membranes between CuHCF electrodes (up to three anion and two cation exchange membranes) reduced energy consumption to only 0.02 kWh/m3 (approximately an order of magnitude lower than values reported for CDI), for an influent desalination similar to CDI (25 mM decreased to 17 mM). These results show that BDI could be effective as a very low energy method for brackish water desalination.

Seawater desalination using small and medium light water reactors

International Nuclear Information System (INIS)

Shimamura, Kazuo

2000-01-01

Water is an essential substance for sustaining human life. As Japan is an island country, surrounded by the sea and having abundant rainfall, there is no scarcity of water in daily life except during abnormally dry summers or after disasters such as earthquakes. Consequently, there is hardly any demand for seawater desalination plants except on remote islands, Okinawa and a part of Kyushu. However, the IAEA has forecast a scarcity of drinking water in developing countries at the beginning of the 21st century. Further, much more irrigation water will be required every year to prevent cultivated areas from being lost by desertification. If developing countries were to produce such water by seawater desalination using current fossil fuel energy technology, it would cause increased air pollution and global warming. This paper explains the concept of seawater desalination plants using small and medium water reactors (hereinafter called 'nuclear desalination'), as well as important matters regarding the export nuclear desalination plants to developing countries. (author)

An experimental study on the cathode humidification and evaporative cooling of polymer electrolyte membrane fuel cells using direct water injection method at high current densities

International Nuclear Information System (INIS)

Hwang, Seong Hoon; Kim, Min Soo

2016-01-01

Highlights: • Proposal of a cathode humidification and evaporative cooling system for PEM fuel cells. • An external-mixing air-assist atomizer is used to produce a very fine water spray. • The system is effective in both cathode humidification and stack cooling. • Increased water flow rate improves stack performance and evaporative cooling capacity. • At a given water flow rate, lower stack temperatures cause greater humidification effect. - Abstract: Humidification and cooling are critical issues in enhancing the efficiency and durability of polymer electrolyte membrane fuel cells (PEMFCs). However, existing humidifiers and cooling systems have the disadvantage that they must be quite large to achieve adequate PEMFC performance. In this study, to eliminate the need for a bulky humidifier and to lighten the cooling load of PEMFCs, a cathode humidification and evaporative cooling system using an external-mixing air-assist atomizer was developed and its performance was investigated. The atomization performance of the nozzle was analyzed experimentally under various operating conditions with minimal changes in the system design. Experiments with a five-cell PEMFC stack with an active area of 250 cm"2 were carried out to analyze the effects of various parameters (such as the operating temperature, current density, and water injection flow rate) on the evaporation of injected water for humidification and cooling performances. The experimental results demonstrate that the direct water injection method proposed in this study is quite effective in cathode humidification and stack cooling in PEM fuel cells at high current densities. The stack performance was improved by humidification effect and the coolant temperature at the stack outlet decreased by evaporative cooling effect.

An experimental investigation on MEDAD hybrid desalination cycle

KAUST Repository

Shahzad, Muhammad Wakil; Thu, Kyaw; Kim, Yong-deuk; Ng, Kim Choon

2015-01-01

This paper presents an advanced desalination cycle called "MEDAD" desalination which is a hybrid of the conventional multi-effect distillation (MED) and an adsorption cycle (AD). The combined cycles allow some of MED stages to operate below ambient

Nuclear energy for seawater desalination - options in future

International Nuclear Information System (INIS)

Yadav, M.K.; Murugan, V.; Balasubramaniyan, C.; Nagaraj, R.; Dangore, Y.

2010-01-01

Full text: With ever increasing water scarcity, many alternatives are being tried to supplement the existing water resources. There are regions where water is scarce and population is growing and is at the mercy of inadequate supplies. Seawater constitutes a practically unlimited source of saline water. When desalted, it can augment the existing potable water resources for the people in nearby area and also meet the increasing demand. BARC has been engaged in the field of desalination and developed expertise in both thermal and membrane technologies. It has setup 6300 M 3 /D Nuclear Desalination Demonstration Project (NDDP) at Kalpakkam, where both membrane and thermal technologies have been used for sea water desalination. Desalination process needs energy and nuclear energy is strong option in view of limited fossil fuels and environmental concerns. Multi Stage Flash (MSF) plant based on thermal technology has been coupled to MAPS Reactors and Sea Water Reverse Osmosis (SWRO) plant is based on membrane technology. This paper discusses various aspects of coupling of desalination plant with nuclear reactors and also discusses salient features of hybridization of thermal and membrane technologies

Economic Considerations of Nuclear Desalination in Korea

International Nuclear Information System (INIS)

Man-Ki, Lee; Seung-Su, Kim

2006-01-01

The objective of this study is to assess the economics of SMART (System-integrated Modular Advanced Reactor) desalination plant in Korea through DEEP (Devaluation Economic Evaluation Program). SMART is mainly designed for the dual purpose of producing water and electricity with the total capacity of 100 MWe which 10 MWe is used for water production and the remains for the electric generation. SMART desalination plant using MED (Multi-Effect Distillation) process is in the stage of the commercial development and its cost information is also being accumulated. In this circumstances, the economic assessment of nuclear desalination by SMART and the effect of water(or electric) supply price to the regional economy is meaningful to the policy maker. This study is focused on the case study analysis about the economics of SMART desalination plant and the meanings of the case study result. This study is composed of two parts. One is prepared to survey the methodology regarding cost allocation between electricity and water in DEEP and the other is for the economic assessment of SMART. The cost allocation methods that have been proposed or used can be classified into two main groups, one is the cost prorating method and the other is the credit method. The cost of an product item in the dual-purpose plant can be determined differently depending on the costing methods adopted. When it comes to applying credit method adopted in this thesis, the production cost of water depends on what kind of the power cost will be chosen in calculating the power credit. This study also analyses the changes of nuclear desalination economics according to the changes of the important factors such as fossil fuel price. I wish that this study can afford to give an insight to the policy maker about SMART desalination plant. (authors)

Sustainable desalination using ocean thermocline energy

KAUST Repository

Ng, Kim Choon

2017-09-22

The conventional desalination processes are not only energy intensive but also environment un-friendly. They are operating far from thermodynamic limit, 10–12%, making them un-sustainable for future water supplies. An innovative desalination processes are required to meet future sustainable desalination goal and COP21 goal. In this paper, we proposed a multi-effect desalination system operated with ocean thermocline energy, thermal energy harnessed from seawater temperature gradient. It can exploit low temperature differential between surface hot water temperature and deep-sea cold-water temperature to produce fresh water. Detailed theoretical model was developed and simulation was conducted in FORTRAN using international mathematical and statistical library (IMSL). We presented four different cases with deep-sea cold water temperature varies from 5 to 13°C and MED stages varies from 3 to 6. It shows that the proposed cycle can achieve highest level of universal performance ratio, UPR = 158, achieving about 18.8% of the ideal limit. With the major energy input emanated from the renewable solar, the proposed cycle is truly a “green desalination” method of low global warming potential (GWP), best suited for tropical coastal shores having bathymetry depths up to 300m or more.

Desalination of brackish and sea water

International Nuclear Information System (INIS)

Shukla, Dilip R.

2005-01-01

In Pali, Rajasthan, a population of 4 lacs gets about 6 million liters of water. Only 34 out of 116 municipalities in AP get regular water. Desalination found acceptance because of the decreasing water table leading to high salinity and making conventional treatment methods irrelevant. While choosing amongst the competitive desalination techniques that are available today for conversion of large quantities of saline water, Reverse Osmosis (RO) and distillation techniques stand out. RO rules the brackish water market where feed salinity is over 700 mg/L. Waste heat is nowadays a non-entity in power plants due to the developments of waste heat recovery systems in power plant technology. Most of the large plants tend to choose thermal desalination. Improved RO economics have in turn increased the attractiveness and use of seawater reverse osmosis (SWRO) technology for many large drinking water projects through out the world. Energy cost is the single largest factor in the cost of Sea Water System (usually 20 to 30% of total cost of water). Nuclear Power Corporation, Kudankulam proposed to build a SW desalination system based on RO technology to meet the water requirement of the Anu Vijay Nagar township and Nuclear Power Station. Energy recovery turbine helps reduce the overall system energy requirement. (author)

Emerging desalination technologies for water treatment: a critical review.

Science.gov (United States)

Subramani, Arun; Jacangelo, Joseph G

2015-05-15

In this paper, a review of emerging desalination technologies is presented. Several technologies for desalination of municipal and industrial wastewater have been proposed and evaluated, but only certain technologies have been commercialized or are close to commercialization. This review consists of membrane-based, thermal-based and alternative technologies. Membranes based on incorporation of nanoparticles, carbon nanotubes or graphene-based ones show promise as innovative desalination technologies with superior performance in terms of water permeability and salt rejection. However, only nanocomposite membranes have been commercialized while others are still under fundamental developmental stages. Among the thermal-based technologies, membrane distillation and adsorption desalination show the most promise for enhanced performance with the availability of a waste heat source. Several alternative technologies have also been developed recently; those based on capacitive deionization have shown considerable improvements in their salt removal capacity and feed water recovery. In the same category, microbial desalination cells have been shown to desalinate high salinity water without any external energy source, but to date, scale up of the process has not been methodically evaluated. In this paper, advantages and drawbacks of each technology is discussed along with a comparison of performance, water quality and energy consumption. Copyright © 2015 Elsevier Ltd. All rights reserved.

Water quality assessment of solar-assisted adsorption desalination cycle

KAUST Repository

Kim, Youngdeuk

2014-07-01

This study focuses on the water quality assessment (feed, product and brine) of the pilot adsorption desalination (AD) plant. Seawater from the Red Sea is used as feed to the AD plant. Water quality tests are evaluated by complying the Environmental Protection Agency (EPA) standards with major primary and secondary inorganic drinking water pollutants and other commonly tested water quality parameters. Chemical testing of desalinated water at the post desalination stage confirms the high quality of produced fresh water. Test results have shown that the adsorption desalination process is very effective in eliminating all forms of salts, as evidenced by the significant reduction of the TDS levels from approximately 40,000. ppm in feed seawater to less than 10. ppm. Test results exhibit extremely low levels of parameters which are generally abundant in feed seawater. The compositions of seawater and process related parameters such as chloride, sodium, bromide, sulfate, calcium, magnesium, and silicate in desalinated water exhibit values of less than 0.1. ppm. Reported conductivity measurements of desalinated water are comparable to distilled water conductivity levels and ranged between 2 and 6. μS/cm while TOC and TIC levels are also extremely low and its value is less than 0.5. ppm. © 2014 Elsevier B.V.

Effect of air humidification on the sick building syndrome and perceived indoor air quality in hospitals: a four month longitudinal study.

Science.gov (United States)

Nordström, K; Norbäck, D; Akselsson, R

1994-01-01

The sensation of dryness and irritation is essential in the sick building syndrome (SBS), and such symptoms are common in both office and hospital employees. In Scandinavia, the indoor relative humidity in well ventilated buildings is usually in the range 10-35% in winter. The aim of this study was to evaluate the effect of steam air humidification on SBS and perceived air quality during the heating season. The study base consisted of a dynamic population of 104 hospital employees, working in four new and well ventilated geriatric hospital units in southern Sweden. Air humidification raised the relative air humidity to 40-45% in two units during a four months period, whereas the other two units served as controls with relative humidity from 25-35%. Symptoms and perceived indoor air quality were measured before and after the study period by a standardised self administered questionnaire. The technical measurements comprised room temperature, air humidity, static electricity, exhaust air flow, aerosols, microorganisms, and volatile organic compounds in the air. The most pronounced effect of the humidification was a significant decrease of the sensation of air dryness, static electricity, and airway symptoms. After four months of air humidification during the heating season, 24% reported a weekly sensation of dryness in humidified units, compared with 73% in controls. No significant changes in symptoms of SBS or perceived air quality over time were found in the control group. The room temperature in all units was between 21-23 degrees C, and no significant effect of air humidification on the air concentration of aerosols or volatile organic compounds was found. No growth of microorganisms was found in the supply air ducts, and no legionella bacteria were found in the supply water of the humidifier. Air humidification, however, significantly reduced the measured personal exposure to static electricity. It is concluded that air humidification during the heating season

Summary of experience and practice in Japanese nuclear desalination plants at the interface between nuclear and desalination systems

International Nuclear Information System (INIS)

Shiota, Y.; Minato, A.

1998-01-01

The widely prevalent large scale desalination of seawater is accomplished by two primary methods: Distillation and reverse osmosis (RO). In any case, an external energy supply source is mandatory for the operation of the desalination plants. Reverse Osmosis is more energy efficient than distillation. The energy input for RO is usually supplied by electric power, whereas thermal energy is extracted from an electric power plant for the distillation processes (dual purpose plant). There are no impediments in using nuclear power plants to supply energy to desalination plants in an integral site. However, it is essential to eliminate the possibility of penetration of radioactive contamination into produced water. Besides, the investigation of possible back-up facilities is detrimental to meet the demand of electric power and water. In accordance with the Japanese regulations, a nuclear power plant cannot be operated if any amount of radioactive contamination resulted from the failure of fuel is detected in the cooling water. In our experience, we have found that no special provisions and no additional selection criteria are needed to install the desalination plants within the nuclear power plants, except for the carbon steel shell utilized for the RO module. (author)

Aerosol delivery and humidification with the Boussignac continuous positive airway pressure device.

Science.gov (United States)

Thille, Arnaud W; Bertholon, Jean-François; Becquemin, Marie-Hélène; Roy, Monique; Lyazidi, Aissam; Lellouche, François; Pertusini, Esther; Boussignac, Georges; Maître, Bernard; Brochard, Laurent

2011-10-01

A simple method for effective bronchodilator aerosol delivery while administering continuing continuous positive airway pressure (CPAP) would be useful in patients with severe bronchial obstruction. To assess the effectiveness of bronchodilator aerosol delivery during CPAP generated by the Boussignac CPAP system and its optimal humidification system. First we assessed the relationship between flow and pressure generated in the mask with the Boussignac CPAP system. Next we measured the inspired-gas humidity during CPAP, with several humidification strategies, in 9 healthy volunteers. We then measured the bronchodilator aerosol particle size during CPAP, with and without heat-and-moisture exchanger, in a bench study. Finally, in 7 patients with acute respiratory failure and airway obstruction, we measured work of breathing and gas exchange after a β(2)-agonist bronchodilator aerosol (terbutaline) delivered during CPAP or via standard nebulization. Optimal humidity was obtained only with the heat-and-moisture exchanger or heated humidifier. The heat-and-moisture exchanger had no influence on bronchodilator aerosol particle size. Work of breathing decreased similarly after bronchodilator via either standard nebulization or CPAP, but P(aO(2)) increased significantly only after CPAP aerosol delivery. CPAP bronchodilator delivery decreases the work of breathing as effectively as does standard nebulization, but produces a greater oxygenation improvement in patients with airway obstruction. To optimize airway humidification, a heat-and-moisture exchanger could be used with the Boussignac CPAP system, without modifying aerosol delivery.

Development of a poultice for electrochemical desalination of porous building materials: desalination effect and pH changes

DEFF Research Database (Denmark)

Rörig-Dalgaard, I.

2013-01-01

vaults two different techniques are applied: poultices or establishment of climate chambers. Both techniques can result in ion transport away from the valuable surfaces with murals, but satisfying desalination has not been obtained according to conservators from the Danish National Museums mural...... experiment with a traditional poultice significant pH changes and an absence of satisfying high desalination effect was measured. The new idea in the present paper was to introduce a calculated amount of buffer components corresponding to the productions during the electrode processes to a poultice (a solid......) to minimize the adverse effects and to optimize on the effects. The results showed good ability to retain neutral pH values in the substrate which is of major importance when the method should be applied on existing structures. Also the desalination process continued until a very low and harmless salt content...

Humidification performance of heat and moisture exchangers for pediatric use.

Science.gov (United States)

Chikata, Yusuke; Sumida, Chihiro; Oto, Jun; Imanaka, Hideaki; Nishimura, Masaji

2012-01-01

Background. While heat and moisture exchangers (HMEs) have been increasingly used for humidification during mechanical ventilation, the efficacy of pediatric HMEs has not yet been fully evaluated. Methods. We tested ten pediatric HMEs when mechanically ventilating a model lung at respiratory rates of 20 and 30 breaths/min and pressure control of 10, 15, and 20 cmH(2)O. The expiratory gas passed through a heated humidifier. We created two rates of leakage: 3.2 L/min (small) and 5.1 L/min (large) when pressure was 10 cmH(2)O. We measured absolute humidity (AH) at the Y-piece. Results. Without leakage, eight of ten HMEs maintained AH at more than 30 mg/L. With the small leak, AH decreased below 30 mg/L (26.6 to 29.5 mg/L), decreasing further (19.7 to 27.3 mg/L) with the large leak. Respiratory rate and pressure control level did not affect AH values. Conclusions. Pediatric HMEs provide adequate humidification performance when leakage is absent.

Humidification Performance of Heat and Moisture Exchangers for Pediatric Use

Directory of Open Access Journals (Sweden)

Yusuke Chikata

2012-01-01

Full Text Available Background. While heat and moisture exchangers (HMEs have been increasingly used for humidification during mechanical ventilation, the efficacy of pediatric HMEs has not yet been fully evaluated. Methods. We tested ten pediatric HMEs when mechanically ventilating a model lung at respiratory rates of 20 and 30 breaths/min and pressure control of 10, 15, and 20 cmH2O. The expiratory gas passed through a heated humidifier. We created two rates of leakage: 3.2 L/min (small and 5.1 L/min (large when pressure was 10 cmH2O. We measured absolute humidity (AH at the Y-piece. Results. Without leakage, eight of ten HMEs maintained AH at more than 30 mg/L. With the small leak, AH decreased below 30 mg/L (26.6 to 29.5 mg/L, decreasing further (19.7 to 27.3 mg/L with the large leak. Respiratory rate and pressure control level did not affect AH values. Conclusions. Pediatric HMEs provide adequate humidification performance when leakage is absent.

Comparison of dehumidification and heat and vent drying of hem-fir softwood

Energy Technology Data Exchange (ETDEWEB)

Mackay, J F.G.; Nielson, R W

1988-03-01

The objective of this project was to demonstrate the performance of dehumidifier kilns, compared to gas-fired, hot-air kilns in drying a commercial grade of softwood lumber. To accomplish this, drying tests were conducted with matched loads of lumber in a new test facility which was constructed to operate as a conventional heat and vent kiln or as a dehumidifier kiln. Comparisons were made of drying times, shrinkage and quality of dried product and total drying energy consumptions. Data from these tests were used in conjunction with capital, energy and other costs obtained from suppliers and operators of existing kilns to make economic comparisons between commercial-sized dehumidifier and heat and vent kilns. These comparisons were made on the basis of equivalent uniform annual costs. Dehumidification drying took about 20% longer and used about 50% of energy compared to heat and vent drying. Analysis of the test runs indicated that further improvements in the energy utilization efficiencies of dehumidifier kilns are feasible since one run indicated an energy consumption of only 36% of that in heat and vent drying. No differences in shrinkage or degrade were apparent. Economic comparisons for three sizes of kilns showed total drying costs by dehumidification to be less for a small-size kiln but more for medium- and large-size operations. Sensitivity analyses were performed to observe the effect of alternate energy prices, dehumidifier energy consumptions, dehumidifier drying times, building costs and degrade. 9 refs., 7 figs., 36 tabs.

Wireless desalination using inductively powered porous carbon electrodes

NARCIS (Netherlands)

Kuipers, J.; Porada, S.

2013-01-01

Water desalination by capacitive deionization (CDI) uses electrochemical cell pairs formed of porous carbon electrodes, which are brought in contact with the water that must be desalinated. Upon applying a cell voltage or current between the electrodes, ions are electrosorbed and water is produced

Membrane-based seawater desalination: Present and future prospects

KAUST Repository

Amy, Gary L.

2016-10-20

Given increasing regional water scarcity and that almost half of the world\\'s population lives within 100 km of an ocean, seawater represents a virtually infinite water resource. However, its exploitation is presently limited by the significant specific energy consumption (kWh/m) required by conventional desalination technologies, further exasperated by high unit costs ($/m) and environmental impacts including GHG emissions (g CO-eq/m), organism impingement/entrainment through intakes, and brine disposal through outfalls. This paper explores the state-of-the-art in present seawater desalination practice, emphasizing membrane-based technologies, while identifying future opportunities in step improvements to conventional technologies and development of emerging, potentially disruptive, technologies through advances in material science, process engineering, and system integration. In this paper, seawater reverse osmosis (RO) serves as the baseline conventional technology. The discussion extends beyond desalting processes into membrane-based salinity gradient energy production processes, which can provide an energy offset to desalination process energy requirements. The future membrane landscape in membrane-based desalination and salinity gradient energy is projected to include ultrahigh permeability RO membranes, renewable-energy driven desalination, and emerging processes including closed-circuit RO, membrane distillation, forward osmosis, pressure retarded osmosis, and reverse electrodialysis according various niche applications and/or hybrids, operating separately or in conjunction with RO.

Life Cycle Assessment for desalination: a review on methodology feasibility and reliability.

Science.gov (United States)

Zhou, Jin; Chang, Victor W-C; Fane, Anthony G

2014-09-15

As concerns of natural resource depletion and environmental degradation caused by desalination increase, research studies of the environmental sustainability of desalination are growing in importance. Life Cycle Assessment (LCA) is an ISO standardized method and is widely applied to evaluate the environmental performance of desalination. This study reviews more than 30 desalination LCA studies since 2000s and identifies two major issues in need of improvement. The first is feasibility, covering three elements that support the implementation of the LCA to desalination, including accounting methods, supporting databases, and life cycle impact assessment approaches. The second is reliability, addressing three essential aspects that drive uncertainty in results, including the incompleteness of the system boundary, the unrepresentativeness of the database, and the omission of uncertainty analysis. This work can serve as a preliminary LCA reference for desalination specialists, but will also strengthen LCA as an effective method to evaluate the environment footprint of desalination alternatives. Copyright © 2014 Elsevier Ltd. All rights reserved.

Desalination demonstration plant using nuclear heat

International Nuclear Information System (INIS)

Hanra, M.S.; Misra, B.M.

1998-01-01

Most of the desalination plants which are operating throughout the world utilize the energy from thermal power station which has the main disadvantage of polluting the environment due to combustion of fossil fuel and with the inevitable rise in prices of fossil fuel, nuclear driven desalination plants will become more economical. So it is proposed to set up nuclear desalination demonstration plant at the location of Madras Atomic Power Station (MAPS), Kalpakkam. The desalination plant will be of a capacity 6300 m 3 /day and based on both Multi Stage Flash (MSF) and Sea Water Reverse Osmosis (SWRO) processes. The MSF plant with performance ratio of 9 will produce water total dissolved solids (TDS-25 ppm) at a rate of 4500 m 3 /day from seawater of 35000 ppm. A part of this water namely 1000 m 3 /day will be used as Demineralised (DM) water after passing it through a mixed bed polishing unit. The remaining 3500 m 3 /day water will be mixed with 1800 m 3 /day water produced from the SWRO plant of TDS of 400 ppm and the same be supplied to industrial/municipal use. The sea water required for MSF and SWRO plants will be drawn from the intake/outfall system of MAPS which will also supply the required electric power pumping. There will be net 4 MW loss of power of MAPS namely 3 MW for MSF and 1 MW for SWRO desalination plants. The salient features of the project as well as the technical details of the both MSF and SWRO processes and its present status are given in this paper. It also contains comparative cost parameters of water produced by both processes. (author)

Experimental validation of a local dehumidification system based on cold water droplets and air-to-air heat exchanger

NARCIS (Netherlands)

Janssen, E.G.O.N.; Hammink, H.A.J.; Hendriksen, L.J.A.M.

2015-01-01

Excessive humidity is a problem in Dutch growing circumstances. A traditional solution is heating and natural ventilation. To save energy a number of energy efficient dehumidification methods are developed, like mechanical ventilation with dry outside air or a curtain of cold water droplets. In this

Energy system impacts of desalination in Jordan

DEFF Research Database (Denmark)

Østergaard, Poul Alberg; Lund, Henrik; Mathiesen, Brian Vad

2014-01-01

and Multi Stage Flash (MSF) desalination driven by Cogeneration of Heat and Power (CHP). The two systems impact the energy systems in different ways due to the technologies’ particular characteristics. The systems are analyses in the energy systems analysis model EnergyPLAN to determine the impacts......Climate change mitigation calls for energy systems minimising end-use demands, optimising the fuel efficiency of conversion systems, increasing the use of renewable energy sources and exploiting synergies wherever possible. In parallel, global fresh water resources are strained due to amongst...... others population and wealth increase and competitive water uses from agriculture and industry is causing many nations to turn to desalination technologies. This article investigates a Jordanian energy scenario with two different desalination technologies; reverse osmosis (RO) driven by electricity...

Desalination by renewable energy: A mini review of the recent patents

Directory of Open Access Journals (Sweden)

Al-Rawajfeh Aiman Eid

2017-01-01

Full Text Available Recent patents on water desalination by using renewable energy technologies are critically reviewed with highlighting on environmental impacts and sustainable development. An overview of using wind, hydroelectric, wave and tidal, wind/solar, geothermal, and solar renewable energy technologies for desalinated water production are assessed. Solar energy is the mother of all other renewable energies; it does not pollute, it is free and available everywhere. Several patents have been invented systems and methods that collected and converted solar energy to electrical energy via solar energy which can be used for water desalination. Wind farm with wind-driven pressurizing devices is used to desalinate salt water by reverse osmosis. Geothermal has been used as an effective method for water desalination. It is highly recommended to provide seawater desalination powered by a renewable energy source in remote areas. On the other hand, sequentially staged of energy conversion steps operate at low efficiencies.

Economics of Renewable Energy for Water Desalination in Developing Countries

Directory of Open Access Journals (Sweden)

Enas R. Shouman

2015-12-01

Full Text Available The aim of this study is to investigate the economics of renewable energy- powered desalination, as applied to water supply for remote coastal and desert communities in developing countries. In this paper, the issue of integration of desalination technologies and renewable energy from specified sources is addressed. The features of Photovoltaic (PV system combined with reverse osmosis desalination technology, which represents the most commonly applied integration between renewable energy and desalination technology, are analyzed. Further, a case study for conceptual seawater reverse osmosis (SW-RO desalination plant with 1000 m3 /d capacity is presented, based on PV and conventional generators powered with fossil fuel to be installed in a remote coastal area in Egypt, as a typical developing country. The estimated water cost for desalination with PV/ SW-RO system is about $1.25 m3 , while ranging between $1.22-1.59 for SW-RO powered with conventional generator powered with fossil fuel. Analysis of the economical, technical and environmental factors depicts the merits of using large scale integrated PV/RO system as an economically feasible water supply relying upon a renewable energy source.

Pushing desalination recovery to the maximum limit: Membrane and thermal processes integration

KAUST Repository

Shahzad, Muhammad Wakil; Burhan, Muhammad; Ng, Kim Choon

2017-01-01

The economics of seawater desalination processes has been continuously improving as a result of desalination market expansion. Presently, reverse osmosis (RO) processes are leading in global desalination with 53% share followed by thermally driven

A prototype for communitising technology: Development of a smart salt water desalination device

Science.gov (United States)

Fakharuddin, F. M.; Fatchurrohman, N.; Puteh, S.; Puteri, H. M. A. R.

2018-04-01

Desalination is defined as the process that removes minerals from saline water or commonly known as salt water. Seawater desalination is becoming an attractive source of drinking water in coastal states as the costs for desalination declines. The purpose of this study is to develop a small scale desalination device and able to do an analysis of the process flow by using suitable sensors. Thermal technology was used to aid the desalination process. A graphical user interface (GUI) for the interface was made to enable the real time data analysis of the desalination device. ArduinoTM microcontroller was used in this device in order to develop an automatic device.

Heated CO(2) with or without humidification for minimally invasive abdominal surgery.

Science.gov (United States)

Birch, Daniel W; Manouchehri, Namdar; Shi, Xinzhe; Hadi, Ghassan; Karmali, Shahzeer

2011-01-19

Intraoperative hypothermia during both open and laparoscopic abdominal surgery may be associated with adverse events. For laparoscopic abdominal surgery, the use of heated insufflation systems for establishing pneumoperitoneum has been described to prevent hypothermia. Humidification of the insufflated gas is also possible. Past studies have shown inconclusive results with regards to maintenance of core temperature and reduction of postoperative pain and recovery times. To determine the effect of heated gas insufflation on patient outcomes following minimally invasive abdominal surgery. The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), MEDLINE (PubMed), EMBASE, International Pharmaceutical Abstracts (IPA), Web of Science, Scopus, www.clinicaltrials.gov and the National Research Register were searched (1956 to 14 June 2010). Grey literature and cross-references were also searched. Searches were limited to human studies without language restriction. All included studies were randomized trials comparing heated (with or without humidification) gas insufflation with cold gas insufflation in adult and pediatric populations undergoing minimally invasive abdominal procedures. Study quality was assessed in regards to relevance, design, sequence generation, allocation concealment, blinding, possibility of incomplete data and selective reporting. The selection of studies for the review was done independently by two authors, with any disagreement resolved in consensus with a third co-author. Screening of eligible studies, data extraction and methodological quality assessment of the trials were performed by the authors. Data from eligible studies were collected using data sheets. Results were presented using mean differences for continuous outcomes and relative risks with 95% confidence intervals for dichotomous outcomes. The estimated effects were calculated using the latest version of RevMan software. Publication bias was taken into

Dry air preservation and corrosion prevention using desiccant dehumidification

International Nuclear Information System (INIS)

Tykesson, M.; Ashworth, C.

1991-01-01

The preservation and longevity of power station plants is a significant problem, particularly in cold shut down situations for prolonged periods of time, and also in storage of parts prior to installation. Power station protection and equipment preservation using the desiccant method is not new. For many years dehumidification machinery has been employed as a barrier to moisture related degradation. The first rotary desiccant dehumidifiers were installed within the power plant industry in the mid 1960s. Many of these first installations remain in operation today. In order to understand the functioning of a desiccant unit as compared with other air handling systems, it is essential to understand the fundamentals of a psychrometric chart. This article will attempt to give the reader an understanding of the subject. (author)

Inadequate humidification of respiratory gases during mechanical ventilation of the newborn.

Science.gov (United States)

Tarnow-Mordi, W O; Sutton, P; Wilkinson, A R

1986-01-01

Proximal airway humidity was measured during mechanical ventilation in 14 infants using an electronic hygrometer. Values below recommended minimum humidity of adult inspired gas were recorded on 251 of 396 occasions. Inadequate humidification, largely due to inadequate proximal airway temperature, is commoner than recognised in infants receiving mechanical ventilation. PMID:3740912

Science Communication and Desalination Research: Water Experts' Views

Science.gov (United States)

Schibeci, R. A.; Williams, A. J.

2014-01-01

Access to clean drinking water is a major problem for many people across the world. Desalination is being increasingly used in many countries to provide this important resource. Desalination technology has received varying degrees of support in the communities in which this technology has been adopted. Productive communication suggests we…

Solar hybrid cooling system for high-tech offices in subtropical climate - Radiant cooling by absorption refrigeration and desiccant dehumidification

International Nuclear Information System (INIS)

Fong, K.F.; Chow, T.T.; Lee, C.K.; Lin, Z.; Chan, L.S.

2011-01-01

Highlights: → A solar hybrid cooling system is proposed for high-tech offices in subtropical climate. → An integration of radiant cooling, absorption refrigeration and desiccant dehumidification. → Year-round cooling and energy performances were evaluated through dynamic simulation. → Its annual primary energy consumption was lower than conventional system up to 36.5%. → The passive chilled beams were more energy-efficient than the active chilled beams. - Abstract: A solar hybrid cooling design is proposed for high cooling load demand in hot and humid climate. For the typical building cooling load, the system can handle the zone cooling load (mainly sensible) by radiant cooling with the chilled water from absorption refrigeration, while the ventilation load (largely latent) by desiccant dehumidification. This hybrid system utilizes solar energy for driving the absorption chiller and regenerating the desiccant wheel. Since a high chilled water temperature generated from the absorption chiller is not effective to handle the required latent load, desiccant dehumidification is therefore involved. It is an integration of radiant cooling, absorption refrigeration and desiccant dehumidification, which are powered up by solar energy. In this study, the application potential of the solar hybrid cooling system was evaluated for the high-tech offices in the subtropical climate through dynamic simulation. The high-tech offices are featured with relatively high internal sensible heat gains due to the intensive office electric equipment. The key performance indicators included the solar fraction and the primary energy consumption. Comparative study was also carried out for the solar hybrid cooling system using two common types of chilled ceilings, the passive chilled beams and active chilled beams. It was found that the solar hybrid cooling system was technically feasible for the applications of relatively higher cooling load demand. The annual primary energy

Feasibilty study of renewable energy powered seawater desalination technology using natural vacuum technique

Energy Technology Data Exchange (ETDEWEB)

Ayhan, Teoman; Al Madani, Hussain [Mechanical Engineering Department, College of Engineering, University of Bahrain, P.O. box 32038, Isatown 32036 (Bahrain)

2010-02-15

With an ever-increasing population and rapid growth of industrialization, there is great demand for fresh water. Desalination has been a key proponent to meet the future challenges due to decreasing availability of fresh water. However, desalination uses significant amount of energy, today mostly from fossil fuels. It is, therefore, reasonable to rely on renewable energy sources such as solar energy, wind energy, ocean thermal energy, waste heat from the industry and other renewable sources. The present study deals with the energy-efficient seawater desalination system utilizing renewable energy sources and natural vacuum technique. A new desalination technology named Natural Vacuum Desalination is proposed. The novel desalination technique achieve remarkable energy efficiency through the evaporation of seawater under vacuum and will be described in sufficient detail to demonstrate that it requires much less electric energy compared to any conventional desalination plant of fresh water production of similar capacity. The discussion will highlight the main operative and maintenance features of the proposed natural vacuum seawater desalination technology which seems to have promising techno-economic potential providing also advantageous coupling with renewable energy sources. (author)

PBMR desalination options: An economic study - HTR2008-58212

International Nuclear Information System (INIS)

De Bruyn, R.; Van Ravenswaay, J. P.; Hannink, R.; Kuhr, R.; Bhagat, K.; Zervos, N.

2008-01-01

The Pebble Bed Modular Reactor (PBMR), under development in South Africa, is an advanced helium-cooled graphite moderated high-temperature gas-cooled nuclear reactor. The heat output of the PBMR is primarily suited for process applications or power generation. In addition, various desalination technologies can be coupled to the PBMR to further improve the overall efficiency and economics, where suitable site opportunities exist. Several desalination application concepts were evaluated for both a cogeneration configuration as well as a waste heat utilization configuration. These options were evaluated to compare the relative economics of the different concepts and to determine the feasibility of each configuration. The cogeneration desalination configuration included multiple PBMR units producing steam for a power cycle, using a back-pressure steam turbine generator exhausting into different thermal desalination technologies. These technologies include Multi-Effect Distillation (MED), Multi-Effect Distillation with Thermal Vapor Compression (MED-TVC) as well as Multi-Stage Flash (MSF) with all making use of extraction steam from back-pressure turbines. These configurations are optimized to maximize gross revenue from combined power and desalinated water sales using representative economic assumptions with a sensitivity analysis to observe the impact of varying power and water costs. Increasing turbine back pressure results in a loss of power output but a gain in water production. The desalination systems are compared as incremental investments. A standard MED process with minimal effects appears most attractive, although results are very sensitive with regards to projected power and water values. (authors)

Seawater desalination in micro grids. An integrated planning approach

Energy Technology Data Exchange (ETDEWEB)

Bognar, Kristina; Behrendt, Frank [Technische Univ. Berlin (Germany). Dept. of Energy Engineering; Blechinger, Philipp [Technische Univ. Berlin (Germany). Dept. of Energy Engineering; Reiner Lemoine Institut gGmbH, Berlin (Germany)

2012-12-15

Islands often depend on the import of fossil fuels for power generation. Due to the combined effect of high oil prices and transportation costs, energy supply systems based on renewable energies are already able to compete successfully with fossil fuel systems for a number of these islands. Depending on local and regional conditions, not only energy supply is a challenge, but also the finding of a reliable supply of water. A promising alternative to freshwater shipments is seawater desalination. Desalination processes can act as a flexible load whenever excess electricity generated by renewable sources is present. Numerical simulations of combined energy and water supply systems for the Caribbean island, Petite Martinique, Grenada, are accomplished. Considering renewable energy sources like wind and solar radiation, energy storage technologies, and desalination processes, various scenarios are introduced and simulated, and the results are compared. An extension of the current energy supply system with renewable energy technologies reduces power generation costs by approximately 40%. The excess energy generated by renewables can supply a significant share of a desalination plant's energy demand. The levelized costs of electricity and water show that the integration of desalination as a deferrable load is beneficial to the considered micro grid. The implementation of renewable energy generation and desalination as deferrable load is recommendable in Petite Martinique. Possible refinancing strategies depending on the combination of different electricity and water tariffs can be derived and applied to similar business cases in remote regions. (orig.)

Seawater desalination plant using nuclear heating reactor coupled with MED process

Institute of Scientific and Technical Information of China (English)

无

2000-01-01

A small size plant for seawater desalination using nuclear heating reactor coupled with MED process was developed by the Institute of Nuclear Energy Technology, Tsinghua University, China. This seawater desalination plant was designed to supply potable water demand to some coastal location or island where both fresh water and energy source are severely lacking. It is also recommended as a demonstration and training facility for seawater desalination using nuclear energy. The design of small size of seawater desalination plant couples two proven technologies: Nuclear Heating Reactor (NHR) and Multi-Effect Destination (MED) process. The NHR design possesses intrinsic and passive safety features, which was demonstrated by the experiences of the project NHR-5. The intermediate circuit and steam circuit were designed as the safety barriers between the NHR reactor and MED desalination system. Within 10～200 MWt of the power range of the heating reactor, the desalination plant could provide 8000 to 150,000 m3/d of high quality potable water. The design concept and parameters, safety features and coupling scheme are presented.

Seawater desalination plant using nuclear heating reactor coupled with MED process

International Nuclear Information System (INIS)

Wu Shaorong; Dong Duo; Zhang Dafang; Wang Xiuzhen

2000-01-01

A small size plant for seawater desalination using nuclear heating reactor coupled with MED process was developed by the Institute of Nuclear Energy Technology, Tsinghua University, China. this seawater desalination plant was designed to supply potable water demand to some coastal location or island where both fresh water and energy source are severely lacking. It is also recommended as a demonstration and training facility for seawater desalination using nuclear energy. The design of small size of seawater desalination plant couples two proven technologies: Nuclear Heating Reactor (NHR) and Multi-Effect Destination (MED) process. The NHR design possesses intrinsic and passive safety features, which was demonstrated by the experiences of the project NHR-5. the intermediate circuit and steam circuit were designed as the safety barriers between the NHR reactor and MED desalination system. Within 10-200 MWt of the power range of the heating reactor, the desalination plant could provide 8000 to 150,000 m 3 /d of high quality potable water. The design concept and parameters, safety features and coupling scheme are presented

Potential Effects of Desalinated Seawater on Arteriosclerosis in Rats.

Science.gov (United States)

Duan, Lian; Zhang, Li Xia; Zhang, Shao Ping; Kong, Jian; Zhi, Hong; Zhang, Ming; Lu, Kai; Zhang, Hong Wei

2017-10-01

To evaluate the potential risk of arteriosclerosis caused by desalinated seawater, Wistar rats were provided desalinated seawater over a 1-year period, and blood samples were collected at 0, 90, 180, and 360 days. Blood calcium, magnesium, and arteriosclerosis-related indicators were investigated. Female rats treated with desalinated seawater for 180 days showed lower magnesium levels than the control rats (P seawater for 360 days (P seawater, and no increase in risk of arteriosclerosis was observed. Copyright © 2017 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

Development of a novel rotary desiccant cooling cycle with isothermal dehumidification and regenerative evaporative cooling using thermodynamic analysis method

International Nuclear Information System (INIS)

La, D.; Li, Y.; Dai, Y.J.; Ge, T.S.; Wang, R.Z.

2012-01-01

A novel rotary desiccant cooling cycle is proposed and studied using thermodynamic analysis method. The proposed cycle integrates the technologies of isothermal dehumidification and regenerative evaporative cooling, which are beneficial for irreversibility reduction. Thermodynamic investigation on the basic rotary desiccant cooling cycle shows that the exergy efficiency of the basic cycle is only 8.6%. The processes of desiccant dehumidification and evaporative cooling, which are essentially the basis for rotary desiccant cooling, affect the exergy performance of the cycle greatly and account for about one third of the total exergy destruction. The proposed cycle has potential to improve rotary desiccant cooling technology. It is advantageous in terms of both heat source utilization rate and space cooling capacity. The exergy efficiency of the new cycle is enhanced significantly to 29.1%, which is about three times that of the ventilation cycle, and 60% higher than that of the two-stage rotary desiccant cooling cycle. Furthermore, the regeneration temperature is reduced from 80 °C to about 60 °C. The corresponding specific exergy of the supply air is increased by nearly 30% when compared with the conventional cycles. -- Highlights: ► A novel rotary desiccant cooling cycle is developed using thermodynamic analysis method. ► Isothermal dehumidification and regenerative evaporative cooling have been integrated. ► The cycle is advantageous in terms of both heat source utilization rate and space cooling capacity. ► Cascaded energy utilization is beneficial for cycle performance improvement. ► Upper limits, which will be helpful to practical design and optimization, are obtained.

Examining the economics of seawater desalination using the DEEP code

International Nuclear Information System (INIS)

2000-11-01

This Technical Document presents analysis of the results of the study initiated by the IAEA on comparison of costs of nuclear and fossil fuel energy sources coupled with selected seawater desalination processes, including regional studies and sensitivity analysis. The economical modelling was performed with use of the Desalination Economic Evaluation Program code (DEEP) released in 1998 which incorporated the latest advances in economic modelling and technological changes in both desalination and reactor technologies

Modern air humidification in the tension field of hygiene and technology; Moderne Luftbefeuchtung im Spannungsfeld von Hygiene und Technik

Energy Technology Data Exchange (ETDEWEB)

Huester, R. [SCIENTICON Scientific Consulting, Rielasingen (Germany)

2006-07-01

The new methods of air conditioning must also guarantee sufficient air humidification in the supplied rooms. In order to avoid the humidified air being a special risk for diseases and allergies, the drinking water quality and humidification technology must be adjusted to each other. The use of water with a low content of alive or dead bacteria or cell components is as important as avoiding large magnitudes of aerosols, which access lungs or alveoli. (orig.)

A comparative study of parameters used in design and operation of desalination experimental facility versus the process parameters in a commercial desalination plant

International Nuclear Information System (INIS)

Hanra, M.S.; Verma, R.K.; Ramani, M.P.S.

1982-01-01

Desalination Experimental Facility (DEF) based on multistage flash desalination process has been set up by the Desalination Division of the Bhabha Atomic Research Centre, Bombay. The design parameters of DEF and materials used for various equipment and parts of DEF are mentioned. DEF was operated for 2300 hours in six operational runs. The range of operational parameters maintained during operation and observations on the performance of the materials of construction are given. Detailed comparison has been made for the orocess parameters in DEF and those in a large size plant. (M.G.B.)

Some interesting aspects of water, with special reference to nuclear desalination

International Nuclear Information System (INIS)

Inam-ur-Rahman

2002-01-01

A brief review is given of the formation, importance, resources and some unique characteristics of water. A reference has been made about the available water racecourse of Pakistan and urgent need of acquiring additional water resources in the county. Importance of water for energy production and energy for acquiring additional water resources is mentioned. Attractive features and feasibility of nuclear desalination, using dual purpose nuclear power plants are discussed. Criteria for selection of suitable reactor type and desalination process are discussed for desired water to power ratios. The world wide growth of desalination capacity, using various desalination processes are listed. (author)

Desalination of water using conventional and nuclear energy

International Nuclear Information System (INIS)

1964-01-01

The purpose of the present publication is to outline the status of desalination of water at the end of 1963, and is intended as a general review of the subject. Since the International Atomic Energy Agency considers that nuclear energy may, in the near future, be important in the conversion of sea and brackish water into fresh water, the following pages will deal mainly with different aspects of desalination on a large scale. These aspects will be discussed in the light of progress made using demonstration plants as well as results obtained in recent design studies. But in no way is it intended to put forward definitive statements on the advantages or disadvantages of using one or another kind of energy or any particular desalination process. This publication should serve as a technical report intended to help in a preliminary evaluation of projects that may be considered. The scientific and technical aspects of desalination will be subject of further study by the Agency. 65 refs, 25 figs, 12 tabs

Short Review on Predicting Fouling in RO Desalination

Directory of Open Access Journals (Sweden)

Alejandro Ruiz-García

2017-10-01

Full Text Available Reverse Osmosis (RO membrane fouling is one of the main challenges that membrane manufactures, the scientific community and industry professionals have to deal with. The consequences of this inevitable phenomenon have a negative effect on the performance of the desalination system. Predicting fouling in RO systems is key to evaluating the long-term operating conditions and costs. Much research has been done on fouling indices, methods, techniques and prediction models to estimate the influence of fouling on the performance of RO systems. This paper offers a short review evaluating the state of industry knowledge in the development of fouling indices and models in membrane systems for desalination in terms of use and applicability. Despite major efforts in this field, there are gaps in terms of effective methods and models for the estimation of fouling in full-scale RO desalination plants. In existing models applied to full-scale RO desalination plants, neither the spacer geometry of membranes, nor the efficiency and frequency of chemical cleanings are considered.

Conjugate heat and mass transfer in heat mass exchanger ducts

CERN Document Server

Zhang, Li-Zhi

2013-01-01

Conjugate Heat and Mass Transfer in Heat Mass Exchanger Ducts bridges the gap between fundamentals and recent discoveries, making it a valuable tool for anyone looking to expand their knowledge of heat exchangers. The first book on the market to cover conjugate heat and mass transfer in heat exchangers, author Li-Zhi Zhang goes beyond the basics to cover recent advancements in equipment for energy use and environmental control (such as heat and moisture recovery ventilators, hollow fiber membrane modules for humidification/dehumidification, membrane modules for air purification, desi

Desalination and water recycling by air gap membrane distillation

NARCIS (Netherlands)

Meindersma, G.W.; Guijt, C.M.; Haan, de A.B.

2006-01-01

Membrane distillation (MD) is an emerging technology for desalination. Membrane distillation differs from other membrane technologies in that the driving force for desalination is the difference in vapour pressure of water across the membrane, rather than total pressure. The membranes for MD are

Desalination and Water Recycling by Air Gap Membrane Distillation

NARCIS (Netherlands)

Meindersma, G.W.; Guijt, C.M.; de Haan, A.B.

2006-01-01

Membrane distillation (MD) is an emerging technology for desalination. Membrane distillation differs from other membrane technologies in that the driving force for desalination is the difference in vapour pressure of water across the membrane, rather than total pressure. The membranes for MD are

Performance analysis of a direct expansion air dehumidification system combined with membrane-based total heat recovery

Energy Technology Data Exchange (ETDEWEB)

Liang, Cai-Hang; Zhang, Li-Zhi; Pei, Li-Xia [Key Laboratory of Enhanced Heat Transfer and Energy Conservation of Education Ministry, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640 (China)

2010-09-15

A direct expansion (DX) air dehumidification system is an efficient way to supply fresh and dry air to a built environment. It plays a key role in preventing the spread of respiratory disease like Swine flu (H1N1). To improve the efficiency of a conventional DX system in hot and humid regions, a new system of DX in combination with a membrane-based total heat exchanger is proposed. Air is supplied with dew points. A detailed mathematical modeling is performed. A cell-by-cell simulation technique is used to simulate its performances. A real prototype is built in our laboratory in South China University of Technology to validate the model. The effects of inlet air humidity and temperature, evaporator and condenser sizes on the system performance are investigated. The results indicate that the model can predict the system accurately. Compared to a conventional DX system, the air dehumidification rate (ADR) of the novel system is 0.5 times higher, and the coefficient of performance (COP) is 1 times higher. Furthermore, the system performs well even under harsh hot and humid weather conditions. (author)

Nuclear desalination and electricity production for islands

International Nuclear Information System (INIS)

Tran Dai Nghiep

2005-01-01

Nuclear desalination is an established and commercially proven technology that is now available and has the potential of further improvement. The technology of a small-sized reactor for desalination and electricity production will be an economically viable option and will also be suitable for islands with geographic, climatic, ecological and hydrological specifics. The operating experiences and achieved safety should benefit the early stage of a national nuclear power programme in developing countries. (author)

DESALINATION AND WATER TREATMENT RESEARCH AT SANDIA NATIONAL LABORATORIES.

Energy Technology Data Exchange (ETDEWEB)

Rigali, Mark J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Miller, James E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Altman, Susan J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Biedermann, Laura [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Brady, Patrick Vane. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Kuzio, Stephanie P. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Nenoff, Tina M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Rempe, Susan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2016-11-01

Water is the backbone of our economy - safe and adequate supplies of water are vital for agriculture, industry, recreation, and human consumption. While our supply of water today is largely safe and adequate, we as a nation face increasing water supply challenges in the form of extended droughts, demand growth due to population increase, more stringent health-based regulation, and competing demands from a variety of users. To meet these challenges in the coming decades, water treatment technologies, including desalination, will contribute substantially to ensuring a safe, sustainable, affordable, and adequate water supply for the United States. This overview documents Sandia National Laboratories' (SNL, or Sandia) Water Treatment Program which focused on the development and demonstration of advanced water purification technologies as part of the larger Sandia Water Initiative. Projects under the Water Treatment Program include: (1) the development of desalination research roadmaps (2) our efforts to accelerate the commercialization of new desalination and water treatment technologies (known as the 'Jump-Start Program),' (3) long range (high risk, early stage) desalination research (known as the 'Long Range Research Program'), (4) treatment research projects under the Joint Water Reuse & Desalination Task Force, (5) the Arsenic Water Technology Partnership Program, (6) water treatment projects funded under the New Mexico Small Business Administration, (7) water treatment projects for the National Energy Technology Laboratory (NETL) and the National Renewable Energy Laboratory (NREL), (8) Sandia- developed contaminant-selective treatment technologies, and finally (9) current Laboratory Directed Research and Development (LDRD) funded desalination projects.

Water quality assessment of solar-assisted adsorption desalination cycle

KAUST Repository

Kim, Youngdeuk; Thu, K.; Masry, Moawya Ezet; Ng, Kim Choon

2014-01-01

in desalinated water exhibit values of less than 0.1. ppm. Reported conductivity measurements of desalinated water are comparable to distilled water conductivity levels and ranged between 2 and 6. μS/cm while TOC and TIC levels are also extremely low and its

Water recycling and desalination by air gap membrane distillation

NARCIS (Netherlands)

Meindersma, G.W.; Guijt, C.M.; de Haan, A.B.

2005-01-01

Because salt and other small components are the most common compounds in wastewater from the process industry, desalination techniques are likely to be suitable as treatment processes in many cases. Although membrane distillation (MD) is a well-known technology for desalination and water treatment,

Nuclear power for desalination

International Nuclear Information System (INIS)

Patil, Siddhanth; Lanjekar, Sanket; Jagdale, Bhushan; Srivastava, V.K.

2015-01-01

Water is one of the most important assets to mankind and without which the human race would cease to exist. Water is required by us right from domestic to industrial levels. As notified by the 'American Nuclear Society' and 'World Nuclear Association' about 1/5 th of the world population does not access to portable water especially in the Asian and African subcontinent. The situation is becoming adverse day by day due to rise in population and industrialization. The need of alternative water resource is thus becoming vital. About 97.5% of Earth is covered by oceans. Desalination of saline water to generate potable water is thus an important topic of research. Currently about 12,500 desalination plants are operating worldwide with a capacity of about 35 million m 3 /day using mainly fossil fuels for generation of large amount of energy required for processing water. These thermal power station release large amount of carbon dioxide and other green house gases. Nuclear reactors are capable of delivering energy to the high energy-intensive processes without any environmental concerns for climate change etc., giving a vision to sustainable growth of desalination process. These projects are currently employed in Kazakhstan, India, Japan, and Pakistan and are coupled to the nuclear reactor for generating electricity and potable water as well. The current climatic scenario favors the need for expanding dual purpose nuclear power plants producing energy and water at the same location. (author)

Floating nuclear energy plants for seawater desalination. Proceedings of a technical committee meeting

International Nuclear Information System (INIS)

1997-05-01

Floating nuclear desalination facilities are one of the alternatives being considered. They may offer a particularly suitable choice for remote locations and small island or coastal communities where the necessary manpower and infrastructure to support desalination plants are not available. In the interest of focusing specific attention on the technology of floating nuclear desalination, the IAEA sponsored a Technical Committee Meeting on Floating Nuclear Plants for Seawater Desalination from 29 to 31 May 1995 in Obninsk, Russian Federation. This publication documents the papers and presentations given by experts from several countries at that meeting. It is hoped that the information contained in this report will be a valuable resource for those interested in nuclear desalination, and that it will stimulate further interest in the potential for floating nuclear desalination facilities. Refs, figs, tabs

Future sustainable desalination using waste heat: kudos to thermodynamic synergy

KAUST Repository

Shahzad, Muhammad Wakil

2015-12-02

There has been a plethora of published literature on thermally-driven adsorption desalination (AD) cycles for seawater desalination due to their favorable environmentally friendly attributes, such as the ability to operate with low-temperature heat sources, from either the renewable or the exhaust gases, and having almost no major moving parts. We present an AD cycle for seawater desalination due to its unique ability to integrate higher water production yields with the existing desalination methods such as reverse osmosis (RO), multi-stage flashing (MSF) and multi-effect distillation (MED), etc. The hybrid cycles exploit the thermodynamic synergy between processes, leading to significant enhancement of the systems\\' performance ratio (PR). In this paper, we demonstrate experimentally the synergetic effect between the AD and MED cycles that results in quantum improvement in water production. The unique feature is in the internal latent heat recovery from the condenser unit of AD to the top-brine stage of MED, resulting in a combined, or simply termed as MEAD, cycle that requires no additional heat input other than the regeneration of an adsorbent. The batch-operated cycles are simple to implement and require low maintenance when compared with conventional desalination methods. Together, they offer a low energy and environmentally friendly desalination solution that addresses the major issues of the water-energy-environment nexus. © 2016 The Royal Society of Chemistry.

Adsorption desalination—Principles, process design, and its hybrids for future sustainable desalination

KAUST Repository

Shahzad, Muhammad Wakil; Burhan, Muhammad; Ang, Li; Ng, Kim Choon

2018-01-01

The energy, water, and environment nexus is a crucial factor when considering the future development of desalination plants or industry in water-stressed economies. The new generation of desalination processes or plants has to meet the stringent environment discharge requirements and yet the industry remains highly energy efficient and sustainable when producing good potable water. Water sources, either brackish or seawater, have become more contaminated as feed while the demand for desalination capacities increases around the world. One immediate solution for energy efficiency improvement comes from the hybridization of the proven desalination processes to the newer processes of desalination: For example, the integration of the available heat-driven to adsorption desalination (AD) cycles where significant thermodynamic synergy can be attained when cycles are combined. For these hybrid cycles, a quantum improvement in energy efficiency as well as an increase in water production can be expected. The advent of MED with AD cycles, or simply called the MED-AD cycles, is one such example where seawater desalination can be pursued and operated in cogeneration with the electricity production plants: The hybrid desalination cycles utilize only the low exergy bled-stream at low temperatures, complemented with waste exhaust or renewable solar thermal heat at temperatures between 60°C and 80°C. In this chapter, the authors have reported their pioneered research on aspects of AD and related hybrid MED-AD cycles, both at theoretical models and experimental pilots. Using the cogeneration of electricity and desalination concepts, the authors examine the cost apportionment of fuel cost by the quality or exergy of the working steam for such cogeneration configurations.

Adsorption desalination—Principles, process design, and its hybrids for future sustainable desalination

KAUST Repository

Shahzad, Muhammad Wakil

2018-05-03

The energy, water, and environment nexus is a crucial factor when considering the future development of desalination plants or industry in water-stressed economies. The new generation of desalination processes or plants has to meet the stringent environment discharge requirements and yet the industry remains highly energy efficient and sustainable when producing good potable water. Water sources, either brackish or seawater, have become more contaminated as feed while the demand for desalination capacities increases around the world. One immediate solution for energy efficiency improvement comes from the hybridization of the proven desalination processes to the newer processes of desalination: For example, the integration of the available heat-driven to adsorption desalination (AD) cycles where significant thermodynamic synergy can be attained when cycles are combined. For these hybrid cycles, a quantum improvement in energy efficiency as well as an increase in water production can be expected. The advent of MED with AD cycles, or simply called the MED-AD cycles, is one such example where seawater desalination can be pursued and operated in cogeneration with the electricity production plants: The hybrid desalination cycles utilize only the low exergy bled-stream at low temperatures, complemented with waste exhaust or renewable solar thermal heat at temperatures between 60°C and 80°C. In this chapter, the authors have reported their pioneered research on aspects of AD and related hybrid MED-AD cycles, both at theoretical models and experimental pilots. Using the cogeneration of electricity and desalination concepts, the authors examine the cost apportionment of fuel cost by the quality or exergy of the working steam for such cogeneration configurations.

An experimental investigation of a novel design air humidifier using direct solar thermal heating

International Nuclear Information System (INIS)

Abd-ur-Rehman, Hafiz M.; Al-Sulaiman, Fahad A.

2016-01-01

the optimum operating conditions of the humidifier for its possible integration with the dehumidifier. Consequently, an improved humidification-dehumidification desalination system attained.

Microporous Silica Based Membranes for Desalination

Directory of Open Access Journals (Sweden)

João C. Diniz da Costa

2012-09-01

Full Text Available This review provides a global overview of microporous silica based membranes for desalination via pervaporation with a focus on membrane synthesis and processing, transport mechanisms and current state of the art membrane performance. Most importantly, the recent development and novel concepts for improving the hydro-stability and separating performance of silica membranes for desalination are critically examined. Research into silica based membranes for desalination has focussed on three primary methods for improving the hydro-stability. These include incorporating carbon templates into the microporous silica both as surfactants and hybrid organic-inorganic structures and incorporation of metal oxide nanoparticles into the silica matrix. The literature examined identified that only metal oxide silica membranes have demonstrated high salt rejections under a variety of feed concentrations, reasonable fluxes and unaltered performance over long-term operation. As this is an embryonic field of research several target areas for researchers were discussed including further improvement of the membrane materials, but also regarding the necessity of integrating waste or solar heat sources into the final process design to ensure cost competitiveness with conventional reverse osmosis processes.

Desalination of Walls and Façades

Science.gov (United States)

Wedekind, W.; Jáuregui Arreola, K.; Siegesmund, S.

2012-04-01

For large monumental objects like walls and façades, the common technique of applying poultices for desalination often are not effective. This practice is neither cost effective nor does it lead to the desired result of desalination. To manage the conservation and desalination of these kinds of objects, several sprinkling techniques are known and have been applied on historical objects. For example, in the wooden warship Vasa, which was excavated from the sea bottom in Stockholm/Sweden, a sprinkling method was applied in 1961 for conservation and desalination. A sprinkling method to desalinate porous mineral materials will be presented using three different case studies: the rock cut monument no. 825 in Petra/Jordan, the medieval monastary church of the former Franziscan convent in Zeitz/Germany and the baroque monastary church Santa Monica in Guadalajara/Mexico. Before to start with practical conservation, the material- and petropysical properties, focoussed on water transport properties, like porosity, pore size distribution, water uptake and drying rate were investigadet. Diagnostic investigations on the objects included the mapping of deterioration, moister content measurements and salt accumulation determined by borehole cuts samples at depth. In the sprinkling method water is sprayed onto the wall surface through nozzels arranged in a modular grid. Depending on the sprinkling duration, a small or a large amount of water seeps into the porous materials, whereby the depth penetration can be adjusted accordingly. The water not absorbed by the stone runs off the facade and can be collected in liter amounts and tested by electrical conductivity with respect to the dissolved substances. After the drying of the wall's surface and the accumulation of salt at the material's surface, the procedure is repeated. For each subsequent washing a lower content of salt should be brought to the surface. Step by step the salt concentration will eventually decrease to almost

Desalination - an alternative freshwater resource

International Nuclear Information System (INIS)

Shakaib, M.

2005-01-01

Global water constitutes 94 percent salt water that is from the oceans and 6% is in the form of freshwater. Out of this 6% freshwater approximately 27% is trapped in glaciers and 72% is underground. The sea water is important for transportation, fisheries. Oceans regulate climate through air sea interaction. However direct consumption of sea water is too salty to sustain human life. Water with a dissolved solids (salt) content generally below about 1000 milligrams per liter (mg/L) is considered acceptable for human consumption. The application of desalting technologies over the past 50 years have been in many of the arid zone where freshwater is available. Pakistan lies in the Sun Belt. It is considered a wide margin coastal belt (990 km), having an Exclusive Economic Zone of 240,000 km/sup 2/, that strokes trillion cubic meters of sea water that can be made available as freshwater source to meet the shortfall in the supply of domestic water through desalination along the coastal belt of Pakistan. The freshwater obtained from the other desalination processes is slightly expensive, but the cost of desalination can be considerably reduced provided that the available inexpensive or free waste energy is utilized mainly. (author)

A feasibility and efficacy trial of a hand-held humidification device in patients undergoing radiotherapy for head and neck cancer.

Science.gov (United States)

Ghosh, Priyanka; Lazar, Ann A; Ryan, William R; Yom, Sue S

2017-08-01

This study aimed to evaluate the effects of warm-mist humidification during and after head and neck radiation therapy (HN RT) on quality of life (QOL), as measured by the M. D. Anderson Symptom Inventory-Head and Neck (MDASI-HN) HN score. A secondary aim was to compare QOL among compliers (≥60% of protocol-recommended usage) versus non-compliers. Twenty patients self-administered a hand-held, self-sterilizing humidification device for a recommended time of at least 15 min twice daily for 12 weeks. Patients completed the MDASI-HN instrument at RT start, after 6 weeks, and after 12 weeks. Compliance was reported weekly. The average HN score at baseline was 1.7 (SD = 1.8) and increased to 6.0 (SD = 1.6) after 6 weeks; this increase was much higher than anticipated and the primary endpoint could not be reached. However, compliers had an average of nearly two less HN symptoms (-1.8, 95% CI -4 to 0.2; p = 0.08) than non-compliers at 6 weeks and fewer symptoms at 12 weeks as well (-0.9, 95% CI -2.9 to 1.2; p = 0.39). The most common terms patients used to describe humidification were "helpful" and "soothing." Compliance with humidification during RT was associated with fewer reported HN symptoms and a strong trend to better QOL. Improvements were seen from compliance with occasional required use of a portable, inexpensive device. Our findings support continued efforts to reduce barriers to humidification, as an intervention that should be considered for standard HN RT clinical practice.

Current activities on nuclear desalination in the Russian Federation

International Nuclear Information System (INIS)

Baranaev, Y.D.

1996-01-01

The goal of the RF desalination programme has been to develop small power floating nuclear seawater desalination complex based on KLT-40 reactor, originally developed for ship propulsion, as an energy source. Russia has sufficient fresh water resource rather evenly distributed over country territory (except for several specific conditions where sea or brackish water desalination is required for reliable long term potable water supply) and only limited internal deployment of this system is expected. Therefore, the development programme is mostly oriented to external market. Development of the floating nuclear desalination complex goes in parallel and is backed by the project of floating nuclear electricity and heat cogeneration plant using two KLT-40 reactors. This plant producing up to 70 MW(e) of electricity and up to 50 Gcal/of heat for district heating is now at the basic design stage and planned to be implemented around the year 2000 in Russia, at the Arctic Sea area

Marine monitoring surveys for desalination plants-A critical review

KAUST Repository

Lattemann, Sabine

2013-01-01

Environmental impact assessment (EIA) studies are standard practice and a regulatory requirement for most new desalination projects today. However, most of the EIA studies are limited to predictive information; that is, they gather information on the project and the project\\'s environment before project implementation to make predictions about likely impacts. The EIAs may involve comprehensive studies, such as field monitoring, laboratory toxicity testing, and modeling studies. Consequently, the"surprising paucity of useful experimental data, either from laboratory tests or from field monitoring studies", which was observed by the US National Research Council in 2008, has been gradually decreasing. However, there is still a long-term research need on the site-specific effects of desalination plants after project commissioning has taken place. A main challenge of field research is the adequate design of the monitoring studies, which have to adequately distinguish the effects of the desalination project from natural processes over long periods of time. The existing monitoring studies have so far used a wide range of approaches and methods to investigate the environmental impacts of desalination plant discharges. Shortfalls are often that they are limited in scope, short-term, or localized. In essence, many studies fall short of recognizing the potentially synergetic effects of the single waste components of the discharges on marine organisms and the complexity of the potential responses by the ecosystem. While the possible risk of damage arising from the concentrate discharge to the marine environment in close proximity to the outfall is at hand, no conclusive evidence can yet be provided concerning the long-term impacts of desalination plant discharges, let alone the cumulative impacts on certain sea areas. This paper conducts a critical review of existing monitoring programs for desalination plants. Shortcomings of current practices are identified and relevant

Future sustainable desalination using waste heat: kudos to thermodynamic synergy

KAUST Repository

Shahzad, Muhammad Wakil; Ng, Kim Choon; Thu, Kyaw

2015-01-01

There has been a plethora of published literature on thermally-driven adsorption desalination (AD) cycles for seawater desalination due to their favorable environmentally friendly attributes, such as the ability to operate with low-temperature heat

Use of reactor plants of enhanced safety for sea water desalination, industrial and district heating

International Nuclear Information System (INIS)

Panov, Yu.; Polunichev, V.; Zverev, K.

1997-01-01

Russian designers have developed and can deliver nuclear complexes to provide sea water desalination, industrial and district heating. This paper provides an overview of these designs utilizing the ABV, KLT-40 and ATETS-80 reactor plants of enhanced safety. The most advanced nuclear powered water desalination project is the APVS-80. This design consists of a special ship equipped with the distillation desalination plant powered at a level of 160 MW(th) utilizing the type KLT-40 reactor plant. More than 20 years of experience with water desalination and reactor plants has been achieved in Aktau and Russian nuclear ships without radioactive contamination of desalinated water. Design is also proceeding on a two structure complex consisting of a floating nuclear power station and a reverse osmosis desalination plant. This new technology for sea water desalination provides the opportunity to considerably reduce the specific consumption of power for the desalination of sea water. The ABV reactor is utilized in the ''Volnolom'' type floating nuclear power stations. This design also features a desalinator ship which provides sea water desalination by the reverse osmosis process. The ATETS-80 is a nuclear two-reactor cogeneration complex which incorporates the integral vessel-type PWR which can be used in the production of electricity, steam, hot and desalinated water. (author). 9 figs

Economic Investigation of Different Configurations of Inclined Solar Water Desalination Systems

Directory of Open Access Journals (Sweden)

O. Phillips Agboola

2014-02-01

Full Text Available This study empirically investigated the performance of four configurations of inclined solar water desalination (ISWD system for parameters such as daily production, efficiency, system cost, and distilled water production cost. The empirical findings show that in terms of daily productivity improved inclined solar water desalination (IISWD performed best with 6.41 kg/m2/day while improved inclined solar water desalination with wire mesh (IISWDWM produced the least with 3.0 kg/m2/day. In terms of cost price of the systems, the control system inclined solar water desalination (ISWD is the cheapest while IISWDWM is the most expensive system. Distilled water cost price ranges from 0.059 TL/kg, for IISWDW, to 0.134 TL/kg, for IISWDWM system. All the systems are economically and technically feasible as a solar desalination system for potable water in northern Cyprus. Potable water from vendors/hawkers ranges from 0.2 to 0.3 TL/kg.

Study of the Utilization BWR Type Nuclear Power Reactor for Desalination Process

International Nuclear Information System (INIS)

Itjeu Karliana; Sumijanto; Dhandhang Purwadi, M.

2008-01-01

The needs of fresh water increased by rapid population growth and industrials expansion, but these demands can not be prepared naturally. Following this case, seawater desalination becomes the primer option which can fulfill the need through the nuclear desalination technology. The coupled nuclear power reactor enables to supply thermal energy for auxiliary equipment and pumps operation. The utilization study of power reactor type BWR coupled with desalination process has been performed. The goal of study is to obtain characteristic data of desalted water specification which desalination system coupling with nuclear power plant produced energy for desalination process. The study is carried out by browsing data and information, and comprehensive review of thermal energy correlation between NPP with desalination process installation. According to reviewing are found that the thermal energy and electric power utilization from the nuclear power reactor are enable to remove the seawater to produce desalted water and also to operate auxiliary equipments. The assessment results is VK-300 reactor prototype, BWR type 250 MW(e) power are cogeneration unit can supplied hot steam temperature 285 °C to the extraction turbine to empower 150 MW electric power, and a part of hot steam 130 °C is use to operate desalination process and remind heat is distribute to the municipal and offices at that region. The coupled of VK-300 reactor power type BWR with desalination installation of MED type enable to produce desalted water with high quality distillate. Based on the economic calculation that the VK-300 reactor power of BWR type produced water distillate capacity is 300.000 m 3 /hour with cost US$ 0.58/m 3 . The coupling VK-300 reactor power type BWR with MED desalination plant is competitive economically. (author)

Technical and economic evaluation of nuclear seawater desalination systems

International Nuclear Information System (INIS)

Grechko, A.G.; Romenkov, A.A.; Shishkin, V.A.

1998-01-01

The IAEA Cogeneration/Desalination Cost Model spreadsheets were used for the economic evaluation of sea water desalination plants coupled with small and medium size nuclear reactors developed in RDIPE. The results of calculations have shown that the cost of potable water is equal to or even below 1$/m 3 . This is very close to similar indices of the best fossil driven desalination plants. For remote and difficult-to-access regions, where the transportation share contributes significantly to the product water cost at fossil plants, the nuclear power sources of these reactor types are cost-efficient and can successfully compete with fossil power sources. (author)

Electro-desalination of glazed tile panels - discussion of possibilities

DEFF Research Database (Denmark)

Dias-Ferreira, Célia; Ottosen, Lisbeth M.; Ribeiro, Alexandra B.

2016-01-01

. In the few experiments conducted on tiles with attached mortar, the mortar was desalinated to a higher degree than the biscuit and successful desalination of the biscuit through the mortar requires further research. In-situ pilot scale tests were performed on highly salt-contaminated walls without tiles...... by placing electrodes at the same side of the wall. Thus it may be possible to desalinate tile panels, without any physical damage of the fragile glaze, by placing electrodes on the back of the wall or by removing some tiles, placing electrodes in their spaces, and extracting the salts from there before...... the tiles are placed back again....

ZVI (Fe0 Desalination: Stability of Product Water

Directory of Open Access Journals (Sweden)

David D. J. Antia

2016-03-01

Full Text Available A batch-operated ZVI (zero valent iron desalination reactor will be able to partially desalinate water. This water can be stored in an impoundment, reservoir or tank, prior to use for irrigation. Commercial development of this technology requires assurance that the partially-desalinated product water will not resalinate, while it is in storage. This study has used direct ion analyses to confirm that the product water from a gas-pressured ZVI desalination reactor maintains a stable salinity in storage over a period of 1–2.5 years. Two-point-three-litre samples of the feed water (2–10.68 g (Na+ + Cl−·L−1 and product water (0.1–5.02 g (Na+ + Cl−·L−1 from 21 trials were placed in storage at ambient (non-isothermal temperatures (which fluctuated between −10 and 25 °C, for a period of 1–2.5 years. The ion concentrations (Na+ and Cl− of the stored feed water and product water were then reanalysed. The ion analyses of the stored water samples demonstrated: (i that the product water salinity (Na+ and Cl− remains unchanged in storage; and (ii the Na:Cl molar ratios can be lower in the product water than the feed water. The significance of the results is discussed in terms of the various potential desalination routes. These trial data are supplemented with the results from 122 trials to demonstrate that: (i reactivity does not decline with successive batches; (ii the process is catalytic; and (iii the process involves a number of steps.

Algal blooms: an emerging threat to seawater reverse osmosis desalination

KAUST Repository

Villacorte, Loreen O.

2014-08-04

Seawater reverse osmosis (SWRO) desalination technology has been rapidly growing in terms of installed capacity and global application over the last decade. An emerging threat to SWRO application is the seasonal proliferation of microscopic algae in seawater known as algal blooms. Such blooms have caused operational problems in SWRO plants due to clogging and poor effluent quality of the pre-treatment system which eventually forced the shutdown of various desalination plants to avoid irreversible fouling of downstream SWRO membranes. This article summarizes the current state of SWRO technology and the emerging threat of algal blooms to its application. It also highlights the importance of studying the algal bloom phenomena in the perspective of seawater desalination, so proper mitigation and preventive strategies can be developed in the near future. © 2014 © 2014 Balaban Desalination Publications. All rights reserved.

Algal blooms: an emerging threat to seawater reverse osmosis desalination

KAUST Repository

Villacorte, Loreen O.; Tabatabai, S. Assiyeh Alizadeh; Dhakal, N.; Amy, Gary L.; Schippers, Jan Cornelis; Kennedy, Maria Dolores

2014-01-01

Seawater reverse osmosis (SWRO) desalination technology has been rapidly growing in terms of installed capacity and global application over the last decade. An emerging threat to SWRO application is the seasonal proliferation of microscopic algae in seawater known as algal blooms. Such blooms have caused operational problems in SWRO plants due to clogging and poor effluent quality of the pre-treatment system which eventually forced the shutdown of various desalination plants to avoid irreversible fouling of downstream SWRO membranes. This article summarizes the current state of SWRO technology and the emerging threat of algal blooms to its application. It also highlights the importance of studying the algal bloom phenomena in the perspective of seawater desalination, so proper mitigation and preventive strategies can be developed in the near future. © 2014 © 2014 Balaban Desalination Publications. All rights reserved.

Nuclear desalination of sea water. Proceedings of an international symposium

International Nuclear Information System (INIS)

1997-01-01

About 250 participants from 24 Member States and seven international organizations took part in the Symposium. A wide variety of topics related to nuclear desalination were reviewed and discussed. These covered the activities of some organizations and institutes, the experience gained in existing nuclear desalination plants and their facilities, national and bilateral programmes, including research, design and development, forecasts for the future and the challenges that lie ahead. It is hoped that the Proceedings will be of value to technical, financial and regulatory decision makers associated with nuclear desalination

Batteryless photovoltaic reverse-osmosis desalination system

Energy Technology Data Exchange (ETDEWEB)

Thomson, M.; Miranda, M.; Gwillim, J.; Rowbottom, A.; Draisey, I.

2001-07-01

The aim of this project was to design an efficient cost-effective batteryless photovoltaic-powered seawater reverse-osmosis desalination system, to deliver in the order of 3 m{sup 3} of fresh drinking water per day. The desalination of seawater to produce fresh drinking water is extremely valuable on islands and in coastal regions wherever natural freshwater is scarce. Existing small-scale desalination equipment, suitable for areas of medium and low population density, often requires a copious and constant supply of energy, either electricity or diesel. If supply of these fuels is expensive or insecure, but the area has a good solar resource, the use of photovoltaic power is an attractive option. Existing demonstrations of photovoltaic-powered desalination generally employ lead-acid batteries, which allow the equipment to operate at a constant flow, but are notoriously problematic in practice. The system developed in this project runs at variable flow, enabling it to make efficient use of the naturally varying solar resource, without need of batteries. In a sense, the freshwater tank is providing the energy storage. In this project, we have reviewed the merits of a wide variety of reverse-osmosis system configurations and component options. We have completed extensive in-house testing and characterisation of major hardware components and used the results to construct detailed software models. Using these, we have designed a system that meets the above project aim, and we have predicted its performance in detail. Our designs show that a system costing 23,055 pounds stirling will produce 1424 m{sup 3} of fresh drinking water annually - an average of just over 3.9 m{sup 3}/day. The system has no fuel costs and no batteries. The overall cost of water, including full maintenance, is 2.00 pounds stirling per m{sup 3}. The energy consumption (photovoltaic-electricity) is typically between 3.2 and 3.7 kWh/m{sup 3} depending on the solar irradiance and feed water

Experimental analysis of pressurised humidification tower for humid air gas turbine cycles. Part A: Experimental campaign

International Nuclear Information System (INIS)

Pedemonte, A.A.; Traverso, A.; Massardo, A.F.

2008-01-01

One of the most interesting methods of water introduction in a gas turbine circuit is represented by the humid air turbine cycle (HAT). In the HAT cycle, the humidification can be provided by a pressurised saturator (i.e. humidification tower or saturation tower), this solution being known to offer several attractive features. This part A is focused on an experimental study of a pressurised humidification tower, with structured packing inside. After a description of the test rig employed to carry out the measuring campaign, the results relating to the thermodynamic process are presented and discussed. The experimental campaign was carried out over 162 working points, covering a relatively wide range of possible operating conditions. Details about measured data are provided in the appendix. It is shown that the saturator's behaviour, in terms of air outlet humidity and temperature, is primarily driven by, in decreasing order of relevance, the inlet water temperature, the inlet water over inlet dry air mass flow ratio and the inlet air temperature. Finally, the exit relative humidity is shown to be consistently over 100%, which may be explained partially by measurement accuracy and droplet entrainment, and partially by the non-ideal behaviour of air-steam mixtures close to saturation

Cogeneration cycles applied to desalination in the Arab World: state of the art

International Nuclear Information System (INIS)

Yassin, Jamal Saleh

2006-01-01

This paper presents a review of cogeneration cycles applied to water desalination in most of the Arab countries. The scarcity of fresh water resources in many countries around the world, and in particular Gulf countries and north African countries such as Libya and Tunisia forced the local authorities to establish many desalination plants to compensate the water shortage. Some plants are conventional for desalination processes only and others are with cogeneration cycle. The high performance of cogeneration cycles encouraged establishing combined power and desalination plants. The present study is intended to provide an overview of cogeneration cycles in conjunction with desalination technologies under the two main resources of energy, fossils and renewables. Thermal technologies, which utilize fossil resource constitute the mainstay of large-scale desalination in the Arab countries and enjoy a relatively important position worldwide. While the technologies which utilize renewable resources such as solar are getting more attention year by year and still under research and almost for small units.(Author)

A comprehensive economic evaluation of integrated desalination systems, including environmental costs

International Nuclear Information System (INIS)

Nisan, S.

2007-01-01

Seawater desalination is now widely accepted as an attractive alternative source of freshwater for domestic and industrial uses. Despite the considerable progress made in the relevant technologies desalination, however, remains an energy intensive process in which the energy cost is the paramount factor. Many papers have already been published on desalination economics but a comprehensive study, based on the exhaustive analysis of a combination of energy sources and desalination processes, using state of the art economic models and realistic assumptions, is still quite rare. The aim of this paper is to fulfil this gap with a view to provide clear choices of techno-economic options to decision makers in a wide range of countries be they from the developed regions or emerging countries

Impact of Desalination on Physical and Mechanical Properties of Lanzhou Loess

Science.gov (United States)

Bing, Hui; Zhang, Ying; Ma, Min

2017-12-01

Soluble salt in soil has a significant influence on the physical and mechanical properties of the soil. We performed desalination experiments on Lanzhou loess, a typical sulfate saline soil, to study the effects of salt on the physical and mechanical properties of the loess and compare variations in the soil properties after desalination. The Atterberg limits of the soil increased after desalination as a result of changes in the soil particle composition and grain refinement. The shear and uniaxial compressive strength of the soil increased as a result of decreased calcitic cementation and other changes to the soil structure. Scanning electron microstructure (SEM) and mercury intrusion porosimetry (MIP) procedures revealed changes to the microstructure and pore-size distribution of the Lanzhou loess after desalination.

Humidification policies for mechanically ventilated intensive care patients and prevention of ventilator-associated pneumonia: a systematic review of randomized controlled trials.

Science.gov (United States)

Niël-Weise, B S; Wille, J C; van den Broek, P J

2007-04-01

The Dutch Working Party on Infection Prevention (WIP) aimed to determine whether certain humidification policies are better than others in terms of prevention of ventilator-associated pneumonia (VAP) in mechanically ventilated intensive care unit (ICU) patients. Publications were retrieved by a systematic search of Medline and the Cochrane Library up to February 2006. All (quasi-) randomized trials and systematic reviews/meta-analyses comparing humidification methods in ventilated ICU patients were selected. Two reviewers independently assessed trial quality and extracted data. If the data was incomplete, clarification was sought from original authors and used to calculate the relative risk of VAP. Data for VAP were combined in the analysis, where appropriate, using a random-effects model. Ten trials were included in the review. In general, the quality of the trials and the way they were reported were unsatisfactory. The results did not show any benefit from specific humidification techniques in terms of reducing VAP. WIP do not recommend either passive or active humidifiers to prevent VAP, nor the type of passive humidifiers to be used. Regarding active humidification, WIP recommends using heated wire circuits. This is due to the theoretical consideration that less condensate reduces colonization and subsequent risk of spread throughout an ICU when condensate is removed.

Canadian nuclear desalination/cogeneration technology development

International Nuclear Information System (INIS)

Humphries, J.R.

1996-01-01

The goal of the CANDESAL program has been to develop innovative applications of existing technologies that would offer an energy efficient, cost effective mechanism for the production of potable water and electricity. Large scale seawater desalination will be an important element in the solution of the global water shortage problem. For nuclear desalination to capture a significant share of this growing market, it must be economically competitive, as well as offer other advantages over more traditional fossil-fueled alternatives. The focus of activities in Canada has been on development of the technology in directions that would result in improved water production efficiency, reduced energy consumption, reduced environmental burden and reduced costs

Nasal high-frequency oscillatory ventilation impairs heated humidification: A neonatal bench study.

Science.gov (United States)

Ullrich, Tim L; Czernik, Christoph; Bührer, Christoph; Schmalisch, Gerd; Fischer, Hendrik S

2017-11-01

Nasal high-frequency oscillatory ventilation (nHFOV) is a novel mode of non-invasive ventilation used in neonates. However, upper airway obstructions due to viscous secretions have been described as specific adverse effects. We hypothesized that high-frequency oscillations reduce air humidity in the oropharynx, resulting in upper airway desiccation. Therefore, we aimed to investigate the effects of nHFOV ventilatory settings on oropharyngeal gas conditions. NHFOV or nasal continuous positive airway pressure (nCPAP) was applied, along with heated humidification, to a previously established neonatal bench model that simulates oropharyngeal gas conditions during spontaneous breathing through an open mouth. A digital thermo-hygro sensor measured oropharyngeal temperature (T) and humidity at various nHFOV frequencies (7, 10, 13 Hz), amplitudes (10, 20, 30 cmH 2 O), and inspiratory-to-expiratory (I:E) ratios (25:75, 33:66, 50:50), and also during nCPAP. Relative humidity was always >99%, but nHFOV resulted in lower mean T and absolute humidity (AH) in comparison to nCPAP (P humidification during nHFOV. © 2017 Wiley Periodicals, Inc.

Closed-Loop Control of Humidification for Artifact Reduction in Capacitive ECG Measurements.

Science.gov (United States)

Leicht, Lennart; Eilebrecht, Benjamin; Weyer, Soren; Leonhardt, Steffen; Teichmann, Daniel

2017-04-01

Recording biosignals without the need for direct skin contact offers new opportunities for ubiquitous health monitoring. Electrodes with capacitive coupling have been shown to be suitable for the monitoring of electrical potentials on the body surface, in particular ECG. However, due to triboelectric charge generation and motion artifacts, signal and thus diagnostic quality is inferior to galvanic coupling. Active closed-loop humidification of capacitive electrodes is proposed in this work as a new concept to improve signal quality. A capacitive ECG recording system integrated into a common car seat is presented. It can regulate the micro climate at the interface of electrode and patient by actively dispensing water vapour and monitoring humidity in a closed-loop approach. As a regenerative water reservoir, silica gel is used. The system was evaluated with respect to subjective and objective ECG signal quality. Active humidification was found to have a significant positive effect in case of previously poor quality. Also, it had no diminishing effect in case of already good signal quality.

Water Desalination with Wires

NARCIS (Netherlands)

Porada, S.; Sales, B.B.; Hamelers, H.V.M.; Biesheuvel, P.M.

2012-01-01

We show the significant potential of water desalination using a novel capacitive wire-based technology in which anode/cathode wire pairs are constructed from coating a thin porous carbon electrode layer on top of electrically conducting rods (or wires). By alternately dipping an array of electrode

Utility/user requirements for the MHTGR desalination plant

International Nuclear Information System (INIS)

Brown, S.J.; Snyder, G.M.

1989-01-01

This paper describes the approach used by Gas-Cooled Reactor Associates (GCRA) and the Metropolitan Water District of Southern California (MWD) in developing Utility/User (U/U) Requirements for the Modular High Temperature Gas-cooled Reactor (MHTGR) Desalination Plant. This is a cogeneration plant that produces fresh water from seawater, and electricity. The U/U requirements for the reference MHTGR plant are used except for those changes necessary to: provide low-grade heat to a seawater desalination process, enable siting in a Southern California coastal area, take advantage of reduced weather extremes where substantial cost reductions are expected, and use seawater cooling instead of a cooling tower. The resulting requirements and the differences from the reference MHTGR requirements are discussed. The nuclear portion of the design is essentially the same as that for the reference MHTGR design. The major differences occur in the turbine-generator and condenser, and for the most part, the design parameters for the reference plant are found to be conservative for the desalination plant. The most important difference in requirements is in the higher seismic levels required for a Southern California site, which requires reassessment and possible modification of the design of some reference plant equipment for use in the desalination plant. (author). 5 refs, 1 tab

Water Desalination using geothermal energy

KAUST Repository

Goosen, M.; Mahmoudi, H.; Ghaffour, NorEddine

2010-01-01

The paper provides a critical overview of water desalination using geothermal resources. Specific case studies are presented, as well as an assessment of environmental risks and market potential and barriers to growth. The availability

The water desalination complex based on ABV-type reactor plant

International Nuclear Information System (INIS)

Panov, Yu.K.; Fadeev, Yu.P.; Vorobiev, V.M.; Baranaev, Yu.D.

1997-01-01

A floating nuclear desalination complex with two barges, one for ABV type reactor plant, with twin reactor 2 x 6 MW(e), and one for reverse osmosis desalination plant, was described. The principal specifications of the ABV type reactor plant and desalination barge were given. The ABV type reactor has a traditional two-circuit layout using an integral type reactor vessel with all mode natural convection of primary coolant. The desalted water cost was estimated to be around US $0.86 per cubic meter. R and D work has been performed and preparations for commercial production are under way. (author)

Numerical simulation and performance investigation of an advanced adsorption desalination cycle

KAUST Repository

Thu, Kyaw; Chakraborty, Anutosh; Kim, Youngdeuk; Myat, Aung; Saha, Bidyut Baran; Ng, Kim Choon

2013-01-01

Low temperature waste heat-driven adsorption desalination (AD) cycles offer high potential as one of the most economically viable and environmental-friendly desalination methods. This article presents the development of an advanced adsorption

A Feasibility Study of Optimal Nuclear Desalination Process for Industrial Water Supply in Korea

International Nuclear Information System (INIS)

Park, Hyunchul; Han, Kiin

2013-01-01

Seawater Desalination can be an alternative technology for water production based on salt separation from seawater. Seawater desalination can produce freshwater with necessary quality by choosing an appropriate desalination process and posttreatment methods of the product water. The commercial seawater desalination processes which are proven and reliable for large scale freshwater production are MSF and MED for evaporative desalination and RO for membrane desalination. Vapor compression plants based on thermal and mechanical compression are also employed for the small and medium capacity ranges. The aim of this study is to compare the characteristics and cost of each process methods and suggest the most efficient and effective method of desalination for an industrial water supply to the National Industrial Complex nearby Nuclear Power Plant. The costs associated with desalination depend on many factors such as capital, energy, labor, chemicals that are specific to the location, plant capacity, product salinity pre-treatment necessities, and other site-related costs for land, plant and brine disposal. A detailed analysis of each situation is thus required to estimate desalination costs. It could be stated that RO cost is lower than distillation one in energy and environmental terms. The optimal capacity(10,000 m 3 /day) was decided to analyze the estimated water usage in nuclear power plants. And then compared the availability of each process, energy consumption, O and M and economic aspects. In terms of economic feasibility study, RO is the most recommendable process in nuclear power plants in Korea

Electrochemical desalination of bricks - Experimental and modeling

DEFF Research Database (Denmark)

Skibsted, Gry; Ottosen, Lisbeth M.; Jensen, Pernille Erland

2015-01-01

Chlorides, nitrates and sulfates play an important role in the salt-decay of porous materials in buildings and monuments. Electrochemical desalination is a technology able to remove salts from such porous materials in order to stop or prevent the decay. In this paper, experimental and numerical......-contaminated bricks with respect to the monovalent ions is discussed. Comparison between the experimental and the simulation results showed that the proposed numerical model is able to predict electrochemical desalination treatments with remarkable accuracy, and it can be used as a predictive tool...

Solar fired combined RO/MED desalination plant integrated with electrical power grid

International Nuclear Information System (INIS)

Alrobaei, H.

2006-01-01

Currently, there is a strong demand for efficient seawater desalination plants, which can meet the tougher environment regulation and energy saving requirements. From this standpoint the present work was undertaken to include proposed scheme (solar Fired Combined Reverse Osmosis (ROY Multi-Effect Distillation (MED) Seawater desalination Plant (SCDP) integrated with electrical power grid (EPG)) for repowering and modification of the conventional grid connected RO desalination plants. The model of SCDP during sunny periods may be applied to the following modes operation: *Full solar desalination (i.e. solar thermal and electrical power generation in solar plant is elivered to the desalination process and the surplus electricity is fed into EPG). *Hybrid solar desalination (I.e. a small share of the electrical power consumption for desalination process compensated by EPG). During cloudly periods and at night the SCDP operates as a conventional RO desalination plant. To establish the range, in which solar energy for seawater desalination would be competitive to fossil energy and investigates the potential effect of the proposed scheme on the repowering effectiveness, mathematical model has been developed. The repowered effectiveness, mathematical model has been developed.The repowered effectiveness in optaimizing model was characterized by the condition of attaining maximum fuel saving in the EPG. The study result shows the effectiveness of proposed scheme for modification and repowering the RO plant. For the case study. (SCDP with maual share of solar electrical power generation 67.4%) the economical effect amount 138.9 ton fuel/year for each MW design thermal energy of parabolic solar collectors array and the corresponding decrease in exhaust gases emission (Nitrogen oxides (NO x ) 0.55 ton/year.MW, carbon dioxides (CO2) 434.9 ton/year.MW). Moreover, implementation of combined RO/MED design for repowering and modification of conventional grid connected RO plant will

Sensitivity analysis and probabilistic assessment of seawater desalination costs fueled by nuclear and fossil fuel

International Nuclear Information System (INIS)

Kavvadias, K.C.; Khamis, I.

2014-01-01

The reliable supply of water and energy is an important prerequisite for sustainable development. Desalination is a feasible option that can solve the problem of water scarcity in some areas, but it is a very energy intensive technology. Moreover, the rising cost of fossil fuel, its uncertain availability and associated environmental concerns have led to a need for future desalination plants to use other energy sources, such as renewables and nuclear. Nuclear desalination has thus the potential to be an important option for safe, economic and reliable supply of large amounts of fresh water to meet the ever-increasing worldwide water demand. Different approaches to use nuclear power for seawater desalination have been considered including utilisation of the waste heat from nuclear reactors to further reduce the cost of nuclear desalination. Various options to implement nuclear desalination relay mainly on policy making based on socio-economic and environmental impacts of available technologies. This paper examines nuclear desalination costs and proposes a methodology for exploring interactions between critical parameters. - Highlights: • The paper demonstrated desalination costs under uncertainty conditions. • Uncertainty for nuclear power prevails only during the construction period. • Nuclear desalination proved to be cheaper and with less uncertainty

Performance investigation of an advanced multi-effect adsorption desalination (MEAD) cycle

KAUST Repository

Thu, Kyaw; Kim, Young Deuk; Shahzad, Muhammad Wakil; Saththasivam, Jayaprakash; Ng, Kim Choon

2015-01-01

This article presents the development of an advanced adsorption desalination system with quantum performance improvement. The proposed multi-effect adsorption desalination (MEAD) cycle utilizes a single heat source i.e., low-temperature hot water

A multi evaporator desalination system operated with thermocline energy for future sustainability

KAUST Repository

Shahzad, Muhammad Wakil

2017-05-05

All existing commercial seawater desalination processes, i.e. thermally-driven and membrane-based reverse osmosis (RO), are operated with universal performance ratios (UPR) varying up to 105, whilst the UPR for an ideal or thermodynamic limit (TL) of desalination is at 828. Despite slightly better UPRs for the RO plants, all practical desalination plants available, hitherto, operate at only less than 12% of the TL, rendering them highly energy intensive and unsustainable for future sustainability. More innovative desalination methods must be sought to meet the needs of future sustainable desalination and these methods should attain an upper UPR bound of about 25 to 30% of the TL. In this paper, we examined the efficacy of a multi-effect distillation (MED) system operated with thermocline energy from the sea; a proven desalination technology that can exploit the narrow temperature gradient of 20°C all year round created between the warm surface seawater and the cold-seawater at depths of about 300–600m. Such a seawater thermocline (ST)-driven MED system, simply called the ST-MED process, has the potential to achieve up to 2 folds improvement in desalination efficiency over the existing methods, attaining about 18.8% of the ideal limit. With the major energy input emanated from the renewable solar, the ST-MED is truly a “green desalination” method of low global warming potential, best suited for tropical coastal shores having bathymetry depths of 300m or more.

On brackish water desalination economics and alternative renewable energies in Mena countries

International Nuclear Information System (INIS)

El Borgi, Anis

2009-01-01

Nowadays, water management in MENA, no longer exclusive to a sectoral issue pertaining to engineering and technical expertise such as irrigation, water supply and water storage, becomes a shared developmental challenge. In order to face an increasingly growing water crisis, attention on balancing the supply and demand for water given the current constraints, needs analysis of conventional and non conventional water resources from a range of perspectives, including considerations about technological dynamics and alternative renewable energies, which are highly recommended. Thanks to engaged technical progress enabling sensitive desalination cost reduction, water crisis could be of lower impacts. For this region being the world leader in desalination technology investments, we are obliged to rexamine the characteristics of alternative renewable energies. To prevent water shortage from being a constraint to economic development and social stability in MENA, we argue brackish water desalination as one of the most promising and viable options, notably in long term for future generations. This paper contains four sections. brackish water characteristics are clarified in section 1. Then in section 2, we focus on factors affecting both desalination costs and desalination implementation costs. A particular attention is spent in section 3 to electro-dialysis reverse (EDR), subsequent capital and O and M costs approximations. Besides, since there is a pressing need for brackish water desalination, which is energy intensive, alternative renewable energies related to desalination technologies are hightlighted in section 4.

Desalination by biomimetic aquaporin membranes: Review of status and prospects

DEFF Research Database (Denmark)

Tang, C.Y.; Zhao, Y.; Wang, R.

2013-01-01

Based on their unique combination of offering high water permeability and high solute rejection aquaporin proteins have attracted considerable interest over the last years as functional building blocks of biomimetic membranes for water desalination and reuse. The purpose of this review is to prov......Based on their unique combination of offering high water permeability and high solute rejection aquaporin proteins have attracted considerable interest over the last years as functional building blocks of biomimetic membranes for water desalination and reuse. The purpose of this review...... is to provide an overview of the properties of aquaporins, their preparation and characterization. We discuss the challenges in exploiting the remarkable properties of aquaporin proteins for membrane separation processes and we present various attempts to construct aquaporin in membranes for desalination......; including an overview of our own recent developments in aquaporin-based membranes. Finally we outline future prospects of aquaporin based biomimetic membrane for desalination and water reuse....

Prospect of floating desalination facilities using nuclear energy in Indonesia

International Nuclear Information System (INIS)

Rusli, A.; Rina, G.; Gunandjar; Subki, I.R.

1997-01-01

This paper summarizes studies on the water demand and supply problems in Indonesia in the last few years. During the dry season in 1990, it was reported that lack of fresh drinking water in Java and Bali amounted to 2.4 x 10 6 ton/month. Since Indonesia consists of more than 13,000 islands, more problems are faced by other islands. The studies are focused on certain regions (groups of islands) which may have a potential for using a floating desalination facility. Water reservoirs in each island and delivery systems from the floating desalination facilities need to be assessed to see the prospective uses of the systems. Cheap, self-forgiving and easily operated systems, using transportable ship mounted desalination facilities, may be required as a solution to the water supply shortages for these islands. Conclusions based on current problems in water demand and supply and comments on the prospective future market using floating desalination facilities in Indonesia are also given. (author). 9 refs, 10 tabs

Sea water desalination utilizing waste heat by low temperature evaporation

International Nuclear Information System (INIS)

Raha, A.; Srivastava, A.; Rao, I.S.; Majumdar, M.; Srivastava, V.K.; Tewari, P.K.

2007-01-01

Economics of a process is controlled by management of energy and resources. Fresh water has become most valued resource in industries. Desalination is a process by which fresh water resource is generated from sea water or brackish water, but it is an energy intensive process. The energy cost contributes around 25-40% to the total cost of the desalted water. Utilization of waste heat from industrial streams is one of the ecofriendly ways to produce low cost desalted water. Keeping this in mind Low Temperature Evaporation (LTE) desalination technology utilizing low quality waste heat in the form of hot water (as low as 50 deg C) or low pressure steam (0.13 bar) has been developed for offshore and land based applications to produce high purity water (conductivity < 2μS/cm) from sea water. The probability of the scale formation is practically eliminated by operating it at low temperature and controlling the brine concentration. It also does not require elaborate chemical pretreatment of sea water except chlorination, so it has no environmental impact. LTE technology has found major applications in nuclear reactors where large quantity of low quality waste heat is available to produce high quality desalted water for make up water requirement replacing conventional ion exchange process. Successful continuous operation of 30 Te/day LTE desalination plant utilizing waste heat from nuclear research reactor has demonstrated the safety, reliability, extreme plant availability and economics of nuclear desalination by LTE technology. It is also proposed to utilize waste heat from Main Heat Transport (MHT) purification circuit of Advanced Heavy Water Reactor (AHWR) to produce about 250 Te/ day high quality desalinated water by Low Temperature Evaporation (LTE) process for the reactor make up and plant utilization. Recently we have commissioned a 50 Te/day 2-effect low temperature desalination plant with cooling tower where the specific energy and cooling water requirement are

R and D areas for next generation desalination and water purification technologies

International Nuclear Information System (INIS)

Raha, A.; Rao, I.S.; Srivastava, V.K.; Tewari, P.K.

2007-01-01

By 2020, desalination and water purification technologies are expected to contribute significantly to ensure a safe, sustainable, affordable and adequate water supply. The cost of producing water from the current generation desalination technologies has declined over time at a rate of only approximately 4% per year. So we need to accelerate our research and development (R and D) activities with a near and long term objective for evolution of current generation desalination technology and to create revolutionary next generation advanced desalination and water purification technologies which will offer a promise of step reduction in cost of producing water. There are five broad technological areas-thermal technologies, membrane technologies, alternate technologies, concentrate management technologies, reuse and recycle technologies that encompass the spectrum of desalination technology. In this paper high priority research areas in all the above technologies areas are discussed to make decision about research direction that will help to mitigate our nation's future water supply challenges. (author)

Assessing environmental performance of humidification technology used in supply of fresh fruit and vegetables

DEFF Research Database (Denmark)

Fabbri, Serena; Owsianiak, Mikolaj

-harvest losses of fruit and vegetables. Humidifiers release a fine mist thereby reducing the difference in water vapour pressure at the surface of the fruit or vegetable and in the air, preventing dry-out of fruits and deterioration. In addition, humidification provides cooling as a result of the evaporation...... scenarios considered strawberries, flat peaches, asparagus, and table grapes. The results show that the technology has the potential to reduce life cycle environmental impacts, provided that it allows reducing food loss in the post-harvest. When compared to the conventional supply chain of lettuce without...... humidification, the impact scores are reduced on average by 2.6, 6.0 and 7.4% when the total losses of the supply chain are decreased by 2, 5 and 6%, respectively (corresponding to low, medium and high efficiency of the technology). This is true for all impact categories, except resource depletion which...

Development of regulatory requirements/guides for desalination unit coupled with nuclear plant

International Nuclear Information System (INIS)

Jo, Jong Chull; Yune, Young Gill; Kim, Woong Sik

2005-10-01

The basic design of System-integrated Modular Advanced Reactor (SMART), a small-to-medium sized integral type pressurized water reactor (PWR) with the capacity of 330MWth, has been developed in Korea. In order to demonstrate the safety and performance of the SMART design, 'Development Project of SMART-P (SMART-Pilot Plant)' has been being performed as one of the 'National Mid and Long-term Atomic Energy R and D Programs', which includes design, construction, and start-up operation of the SMART-P with the capacity of 65MWth, a 1/5 scaled-down design of the SMART. At the same time, a study on the development of regulatory requirements/guides for the desalination unit coupled with nuclear plant has been carried out by KINS in order to prepare for the forthcoming SMART-P licensing. The results of this study performed from August of 2002 to October of 2005 can be summarized as follows: (1) The general status of desalination technologies has been survey. (2) The design of the desalination plant coupled with the SMART-P has been investigated. (3) The regulatory requirements/guides relevant to a desalination unit coupled with a nuclear plant have been surveyed. (4) A direction on the development of domestic regulatory requirements/guides for a desalination unit has been established. (5) A draft of regulatory requirements/guides for a desalination unit has been developed. (6) Expert technical reviews have been performed for the draft regulatory requirements/guides for a desalination unit. The draft regulatory requirements/guides developed in this study will be finalized and can be applied directly to the licensing of the SMART-P and SMART. Furthermore, it will be also applied to the licensing of the desalination unit coupled with the nuclear plant

Class and Home Problems: Humidification, a True "Home" Problem for p. Chemical Engineer

Science.gov (United States)

Condoret, Jean-Stephane

2012-01-01

The problem of maintaining hygrothermal comfort in a house is addressed using the chemical engineer's toolbox. A simple dynamic modelling proved to give a good description of the humidification of the house in winter, using a domestic humidifier. Parameters of the model were identified from a simple experiment. Surprising results, especially…

Water production for irrigation and drinking needs in remote arid communities using closed-system greenhouse: A review

Directory of Open Access Journals (Sweden)

A.E. Kabeel

2015-06-01

Full Text Available Water needs for agriculture, food production and drinking are considered one of the most critical challenges facing the world in the present days. This is due mainly to the scarcity and lack of fresh water resources, and the increasing ground water salinity. Most of these countries have a high solar energy potential. This potential can be best developed by solar desalination concepts and methods specifically suited for rural water supply, irrigation. In this paper, a humidification–dehumidification (HD water desalination system with several technologies for irrigation and drinking needs in remote arid areas is introduced from technical and economic point of views. This study has investigated (1 detailed discussion of technical developments, economical and sustainable aspects; (2 benefits of the new design over traditional applications, desalination and other irrigation methods; (3 specific requirements and implementation challenges in remote and cold regions; (4 performance and reliability improvement possible techniques. Recommended researches and projects leading to high efficiency, economical and sustainable applications of some desalination devices driven by solar energy are highlighted.

Options identification programme for demonstration of nuclear desalination

International Nuclear Information System (INIS)

1996-08-01

This report responds to Resolutions GC(XXXVIII)/RES/7 in 1994 and GC(XXXIX)/RES/15 in 1995 at the IAEA General Conference, which requested the Director General to initiate a two year Options Identification Programme to identify and define practical options for demonstration of nuclear desalination and to submit a report on this programme to the General Conference of 1996. This programme was implemented by a Working Group, consisting of experts from interested Member States and IAEA staff, through a combination of periodic meetings and individual work assignments. It resulted in identification of a few practical options, based on reactor and desalination technologies which are themselves readily available without further development being required at the time of demonstration. The report thus provides a perspective how to proceed with demonstration of nuclear desalination, which is expected to help solving the potable water supply problem in the next century. Refs, figs, tabs

Electrokinetic desalination of sandstones for NaCl removal

DEFF Research Database (Denmark)

Ottosen, Lisbeth M.; Christensen, Iben V.

2012-01-01

of reliable methods to remove the damaging salts in order to stop the decay. Electrokinetic desalination of fired clay bricks have previously shown efficient in laboratory scale and in the present work the method is tested for desalination of Cotta and Posta sandstones, which both have lower porosity than...... each stone, but electroosmosis in the poultices may have caused suction/pressure over the interface between stone and poultice causing the differences in poultice water content. The transport numbers for Cl− and Na+ differed in the two stones and were highest in the most porous Cotta sandstone in spite...... of similar high pore water concentrations and the same applied electric current. The hypotheses is that a layered structure of the sandstones could be the cause for this, as the electric current may preferentially flow in certain paths through the stone, which are thus desalinated first. After...

Energy-water-environment nexus underpinning future desalination sustainability

KAUST Repository

Shahzad, Muhammad Wakil

2017-03-11

Energy-water-environment nexus is very important to attain COP21 goal, maintaining environment temperature increase below 2°C, but unfortunately two third share of CO2 emission has already been used and the remaining will be exhausted by 2050. A number of technological developments in power and desalination sectors improved their efficiencies to save energy and carbon emission but still they are operating at 35% and 10% of their thermodynamic limits. Research in desalination processes contributing to fuel World population for their improved living standard and to reduce specific energy consumption and to protect environment. Recently developed highly efficient nature-inspired membranes (aquaporin & graphene) and trend in thermally driven cycle\\'s hybridization could potentially lower then energy requirement for water purification. This paper presents a state of art review on energy, water and environment interconnection and future energy efficient desalination possibilities to save energy and protect environment.

Electrochemical desalination of historic Portuguese tiles

DEFF Research Database (Denmark)

Ottosen, Lisbeth M.; Dias-Ferreira, Celia; Ribeiro, Alexandra B.

2015-01-01

Soluble salts cause severe decay of historic Portuguese tiles. Treatment options for removal of the salts to stop the decay are few. The present paper deals with development of a method for electrochemical desalination, where an electric DC field is applied to the tiles. Laboratory experiments were...... the electrochemical treatment. The removal rate was similar for the two anions so the chloride concentration reached the lowest concentration level first. At this point the electric resistance increased, but the removal of nitrate continued unaffected till similar low concentration. The sulfate concentration...... was successful. Based on the obtained results an important step is taken towards development of an electrochemical technique for desalination of tile panels....

Technology development and application of solar energy in desalination: MEDRC contribution

KAUST Repository

Ghaffour, NorEddine; Reddy, V. K.; Abu-Arabi, Mousa K.

2011-01-01

Desalination has become one of the sources for water supply in several countries especially in the Middle East and North Africa region. There is a great potential to develop solar desalination technologies especially in this region where solar

Multi criteria sizing approach for Photovoltaic Thermal collectors supplying desalination plant

International Nuclear Information System (INIS)

Ammous, Mahmoud; Chaabene, Maher

2015-01-01

Highlights: • Concept of reverse osmosis desalination plant supplied by hybrid collectors. • Energy consumption optimization. • Plant modeling. • Sizing approach for a desalination plant supplied by hybrid collectors. - Abstract: Reverse osmosis desalination plants require both thermal and electrical energies in order to produce water. As Photovoltaic Thermal panels are able to provide the two energies, they become suitable to supply reverse osmosis plants mainly while installed in remote areas. Autonomous based desalination plants must be optimally sized to meet the criteria related to the reverse osmosis operating temperature, the plant autonomy, the needed water, etc. This paper presents a sizing approach for Photovoltaic Thermal collectors supplying reverse osmosis desalination plant to compute the optimal surface of Photovoltaic Thermal collectors and the tank volume with respect to the operating criteria. The approach is composed of three optimization consideration steps: the monthly average data, the fulfillment of the water need and a three day of autonomy for the water tank volume. The algorithm is tested for a case of study of 10 ha of tomato irrigation. The results converged to 700 m 2 of Photovoltaic Thermal collector’s surface and 3000 m 3 of water tank volume

Emgas pioneers gas conditioning by humidification

Energy Technology Data Exchange (ETDEWEB)

de Winton, C

1975-03-01

As a first solution to any problems of serious joint leaking in low- and medium-pressure distribution networks, East Midlands Gas is using gas conditioning by steam or water injection and/or oil fogging. The project has been conceived on a sufficiently large scale to take in the whole area of supply; plans call for completion over a period of 7 yr. Emgas has based its humidification process on a positive control system, first and foremost to avoid certain serious pitfalls which can befall the casual injection of steam or water into a gas main. The control system used has been built around the Foxboro Dewcel, a thin-walled metal socket covered with a woven glass tape impregnated with lithium chloride. A 25-V ac source is connected to a pair of gold wires wound around the tape.

Forward osmosis niches in seawater desalination and wastewater reuse.

Science.gov (United States)

Valladares Linares, R; Li, Z; Sarp, S; Bucs, Sz S; Amy, G; Vrouwenvelder, J S

2014-12-01

This review focuses on the present status of forward osmosis (FO) niches in two main areas: seawater desalination and wastewater reuse. Specific applications for desalination and impaired-quality water treatment and reuse are described, as well as the benefits, advantages, challenges, costs and knowledge gaps on FO hybrid systems are discussed. FO can play a role as a bridge to integrate upstream and downstream water treatment processes, to reduce the energy consumption of the entire desalination or water recovery and reuse processes, thus achieving a sustainable solution for the water-energy nexus. FO hybrid membrane systems showed to have advantages over traditional membrane process like high pressure reverse osmosis and nanofiltration for desalination and wastewater treatment: (i) chemical storage and feed water systems may be reduced for capital, operational and maintenance cost, (ii) water quality is improved, (iii) reduced process piping costs, (iv) more flexible treatment units, and (v) higher overall sustainability of the desalination and wastewater treatment process. Nevertheless, major challenges make FO systems not yet a commercially viable technology, the most critical being the development of a high flux membrane, capable of maintaining an elevated salt rejection and a reduced internal concentration polarization effect, and the availability of appropriate draw solutions (cost effective and non-toxic), which can be recirculated via an efficient recovery process. This review article highlights the features of hybrid FO systems and specifically provides the state-of-the-art applications in the water industry in a novel classification and based on the latest developments toward scaling up these systems. Copyright © 2014 Elsevier Ltd. All rights reserved.

Forward osmosis niches in seawater desalination and wastewater reuse

KAUST Repository

Valladares Linares, Rodrigo

2014-12-01

This review focuses on the present status of forward osmosis (FO) niches in two main areas: seawater desalination and wastewater reuse. Specific applications for desalination and impaired-quality water treatment and reuse are described, as well as the benefits, advantages, challenges, costs and knowledge gaps on FO hybrid systems are discussed. FO can play a role as a bridge to integrate upstream and downstream water treatment processes, to reduce the energy consumption of the entire desalination or water recovery and reuse processes, thus achieving a sustainable solution for the water-energy nexus. FO hybrid membrane systems showed to have advantages over traditional membrane process like high pressure reverse osmosis and nanofiltration for desalination and wastewater treatment: (i) chemical storage and feed water systems may be reduced for capital, operational and maintenance cost, (ii) water quality is improved, (iii) reduced process piping costs, (iv) more flexible treatment units, and (v) higher overall sustainability of the desalination and wastewater treatment process. Nevertheless, major challenges make FO systems not yet a commercially viable technology, the most critical being the development of a high flux membrane, capable of maintaining an elevated salt rejection and a reduced internal concentration polarization effect, and the availability of appropriate draw solutions (cost effective and non-toxic), which can be recirculated via an efficient recovery process. This review article highlights the features of hybrid FO systems and specifically provides the state-of-the-art applications in the water industry in a novel classification and based on the latest developments toward scaling up these systems.

Combined desalination and solar-assisted air-conditioning system

International Nuclear Information System (INIS)

Gude, Veera Gnaneswar; Nirmalakhandan, Nagamany

2008-01-01

Analysis of a new desalination process utilizing low grade thermal energy is presented. In this process, fresh water is distilled from saline water under near-vacuum pressures created by passive means, enabling low-temperature distillation with lower energy requirements. The energy for low-temperature distillation is provided by a thermal energy storage (TES) system maintained at 55 deg. C utilizing any low grade waste heat source. In this study, heat rejected by the condenser of a modified absorption refrigeration system (ARS) is evaluated as a possible source to drive this desalination process. The energy for the generator of the ARS is provided by a combination of solar collector system and grid power. Results of this study show that the thermal energy rejected by an ARS of cooling capacity of 3.25 kW (0.975 tons of refrigeration) along with an additional energy input of 208 kJ/kg of desalinated water is adequate to produce desalinated water at an average rate of 4.5 kg/h. This energy consumption is competitive with that of the multi-stage flash distillation process of similar capacity (338 kJ/kg). An integrated process model and performance curves of the proposed approach are presented in this paper. Effects of process parameters on the performance of the system are also presented

蓄冰柜在密闭空间中的降温除湿性能分析%Cooling and dehumidification performance ofthe storage freezer in the emergency confined space

Institute of Scientific and Technical Information of China (English)

刘立瑶; 茅靳丰; 侯普民; 陈飞

2017-01-01

To ensure the confined space within the environment of temperature and humidity in the acceptable range, according to the mine chamber cooling and dehumidification technology, a new type of storage freezer cooling and dehumidification device was developed based on numerical simulation of fluent and theoretical calculation.The device adopts the modular design, and the number of ice storage module can be adjusted according to the change of the load, and removed for cooling dehumidification of the natural convection when power is interruption.Melted water can also be used for drinking.Through experiments, cooling and dehumidification performance and insulation properties of the storage freezer in a forced convection conditions were obtained.The results show that under the same ambient conditions of temperature and humidity, the larger the inlet airflow, the larger the total cooling and dehumidification amount, but with the air temperature increase, relative humidity reduces, and cooling and dehumidification effect of the unit mass air decreases.Under the same air flow rate, the higher the ambient temperature and humidity, the more obvious the unit mass air cooling and dehumidification effect.The total heat transfered is approximately in direct proportion to the air flow rate, and the higher the ambient temperature and humidity, the greater the proportion coefficient.Under the condition that the air flow rate is more than 420 m3/h, the storage freezer cooling and dehumidification capacity can meet the cooling load of 15 people in the emergency confined space.%为保证密闭空间内环境的温湿度在人员可接受的范围内,参照矿用救生舱降温除湿技术,基于fluent数值模拟与理论计算,研制了一种新型蓄冰柜降温除湿装置.该装置采用模块化设计,可以根据负�

Long-term market prospects/demand for seawater desalination for municipal supply

International Nuclear Information System (INIS)

Furukawa, D.H.; Zimerman, Z.

1996-01-01

The current status of the seawater desalination market was reviewed, and the expected evolution of installed capacities up to the year 2015 was projected in five year intervals by: Individual countries; unit size; desalination process used. 2 refs, 2 figs

Transient behaviour and coupling aspects of a hybrid MSF-RO nuclear desalination plant

International Nuclear Information System (INIS)

Tewari, P.K.; Misra, B.M.

1998-01-01

BARC is setting up a 6300 M 3 /day (1.4 MGD) hybrid MSF-RO nuclear desalination plant for sea water desalination at Madras Atomic Power Station (MAPS) coupled to a 170 MWe Pressurised Heavy Water Reactor (PHWR). The transient behaviour and coupling aspects of this dual purpose plant has been discussed. A hybrid desalination plant appears to offer high availability factor. (author)

Feasibility study of a dedicate nuclear desalination system: Low-pressure inherent heat sink nuclear desalination plant (LIND)

Energy Technology Data Exchange (ETDEWEB)

Kim, Ho Sik; No, Hee Cheon; Jo, Yu Gwan; Wivisono, Andhika Feri; Park, Byung Ha; Choi, Jin Young; Lee, Jeong Ik; Jeong, Yong Hoon; Cho, Nam Zin [Dept. of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

2015-04-15

In this paper, we suggest the conceptual design of a water-cooled reactor system for a low-pressure inherent heat sink nuclear desalination plant (LIND) that applies the safety-related design concepts of high temperature gas-cooled reactors to a water-cooled reactor for inherent and passive safety features. Through a scoping analysis, we found that the current LIND design satisfied several essential thermal-hydraulic and neutronic design requirements. In a thermal-hydraulic analysis using an analytical method based on the Wooton-Epstein correlation, we checked the possibility of safely removing decay heat through the steel containment even if all the active safety systems failed. In a neutronic analysis using the Monte Carlo N-particle transport code, we estimated a cycle length of approximately 6 years under 200 MW{sub th} and 4.5% enrichment. The very long cycle length and simple safety features minimize the burdens from the operation, maintenance, and spent-fuel management, with a positive impact on the economic feasibility. Finally, because a nuclear reactor should not be directly coupled to a desalination system to prevent the leakage of radioactive material into the desalinated water, three types of intermediate systems were studied: a steam producing system, a hot water system, and an organic Rankine cycle system.

Feasibility study of a dedicated nuclear desalination system: Low-pressure Inherent heat sink Nuclear Desalination plant (LIND

Directory of Open Access Journals (Sweden)

Ho Sik Kim

2015-04-01

Full Text Available In this paper, we suggest the conceptual design of a water-cooled reactor system for a low-pressure inherent heat sink nuclear desalination plant (LIND that applies the safety-related design concepts of high temperature gas-cooled reactors to a water-cooled reactor for inherent and passive safety features. Through a scoping analysis, we found that the current LIND design satisfied several essential thermal–hydraulic and neutronic design requirements. In a thermal–hydraulic analysis using an analytical method based on the Wooton–Epstein correlation, we checked the possibility of safely removing decay heat through the steel containment even if all the active safety systems failed. In a neutronic analysis using the Monte Carlo N-particle transport code, we estimated a cycle length of approximately 6 years under 200 MWth and 4.5% enrichment. The very long cycle length and simple safety features minimize the burdens from the operation, maintenance, and spent-fuel management, with a positive impact on the economic feasibility. Finally, because a nuclear reactor should not be directly coupled to a desalination system to prevent the leakage of radioactive material into the desalinated water, three types of intermediate systems were studied: a steam producing system, a hot water system, and an organic Rankine cycle system.

Study on underground-water restoration of acid in-situ leaching process with electrodialytic desalination

International Nuclear Information System (INIS)

Huang Chongyuan; Meng Jin; Li Weicai

2003-01-01

The study focus undergrounder water restoration of acid in-situ leaching process with electrodialysis desalination in Yining Uranium Mine. It is shown in field test that electrodialysis desalination is an effective method for underground water restoration of acid in-situ leaching process. When TDS of underground-water at the decommissioning scope is 10-12 g/L, and TDS will be less than 1 g/L after the desalination process, the desalination rate is more than 90%, freshwater recovery 60%-70%, power consumption for freshwater recovery 5 kW·h/m 3 , the distance of the desalination flow 12-13 m, current efficiency 80%, and the throughput of the twin membrane 0.22-0.24 m 3 /(m 2 ·d)

Modeling and Simulation of Membrane-Based Dehumidification and Energy Recovery Process

Energy Technology Data Exchange (ETDEWEB)

Gao, Zhiming [ORNL; Abdelaziz, Omar [ORNL; Qu, Ming [ORNL

2017-01-01

This paper introduces a first-order physics-based model that accounts for the fundamental heat and mass transfer between a humid-air vapor stream on feed side to another flow stream on permeate side. The model comprises a few optional submodels for membrane mass transport; and it adopts a segment-by-segment method for discretizing heat and mass transfer governing equations for flow streams on feed and permeate sides. The model is able to simulate both dehumidifiers and energy recovery ventilators in parallel-flow, cross-flow, and counter-flow configurations. The predicted tresults are compared reasonably well with the measurements. The open-source codes are written in C++. The model and open-source codes are expected to become a fundament tool for the analysis of membrane-based dehumidification in the future.

Thermodynamic advantages of nuclear desalination through reverse osmosis

International Nuclear Information System (INIS)

Bhattacharyya, K.P.; Prabhakar, S.; Tewari, P.K.

2009-01-01

Seawater Reverse Osmosis (SWRO) integrated with nuclear power station has significant thermodynamic advantages since it can utilize the waste heat available in the condenser cooling circuit and electrical power from the nuclear power plant with provision for using grid power in case of exigencies and shared infrastructure. Coupling of RO plants to the reactor is simple and straightforward and power loss due to RO unit, resulting in the loss of load, does not impact reactor turbine. Product water contamination probability is also very less since it has in-built mechanical barrier. Preheat reverse osmosis desalination has many thermodynamic advantages and studies have indicated improved performance characteristics thereby leading to savings in operational cost. The significant advantages include the operational flexibility of the desalination systems even while power plant is non-operational and non-requirement of safety systems for resource utilization. This paper brings out a comprehensive assessment of reverse osmosis process as a stand-alone nuclear desalination system. (author)

Characterization of saline groundwater across the coastal aquifer of Israel as resource for desalination

Science.gov (United States)

Stein, Shaked; Russak, Amos; Sivan, Orit; Yechieli, Yospeh; Oren, Yoram; Kasher, Roni

2015-04-01

In arid countries with access to marine water seawater desalination is becoming an important water source in order to deal with the water scarcity and population growth. Seawater reverse osmosis (RO) facilities use open seawater intake, which requires pretreatment processes to remove particles in order to avoid fouling of the RO membrane. In small and medium size desalination facilities, an alternative water source can be saline groundwater in coastal aquifers. Using saline groundwater from boreholes near the shore as feed water may have the advantage of natural filtration and low organic content. It will also reduce operation costs of pretreatment. Another advantage of using groundwater is its availability in highly populated areas, where planning of large RO desalination plants is difficult and expensive due to real-estate prices. Pumping saline groundwater underneath the freshwater-seawater interface (FSI) might shift the interface towards the sea, thus rehabilitating the fresh water reservoirs in the aquifer. In this research, we tested the potential use of saline groundwater in the coastal aquifer of Israel as feed water for desalination using field work and desalination experiments. Specifically, we sampled the groundwater from a pumping well 100 m from the shore of Tel-Aviv and sea water from the desalination plant in Ashqelon, Israel. We used an RO cross flow system in a pilot plant in order to compare between the two water types in terms of permeate flux, permeate flux decline, salt rejection of the membrane and the fouling on the membrane. The feed, brine and fresh desalinated water from the outlet of the desalination system were chemically analyzed and compared. Field measurements of dissolved oxygen, temperature, pH and salinity were also conducted in situ. Additionally, SDI (silt density index), which is an important index for desalination, and total organic carbon that has a key role in organic fouling and development of biofouling, were measured and

Photosynthetic microbial desalination cells (PMDCs) for clean energy, water and biomass production.

Science.gov (United States)

Kokabian, Bahareh; Gude, Veera Gnaneswar

2013-12-01

Current microbial desalination cell (MDC) performances are evaluated with chemical catalysts such as ferricyanide, platinum catalyzed air-cathodes or aerated cathodes. All of these methods improve power generation potential in MDCs, however, they are not preferable for large scale applications due to cost, energy and environmental toxicity issues. In this study, performance of microbial desalination cells with an air cathode and an algae biocathode (Photosynthetic MDC - PMDC) were evaluated, both under passive conditions (no mechanical aeration or mixing). The results indicate that passive algae biocathodes perform better than air cathodes and enhance COD removal and utilize treated wastewater as the growth medium to obtain valuable biomass for high value bioproducts. Maximum power densities of 84 mW m(-3) (anode volume) or 151 mW m(-3) (biocathode volume) and a desalination rate of 40% were measured with 0.9 : 1 : 0.5 volumetric ratios of anode, desalination and algae biocathode chambers respectively. This first proof-of-concept study proves that the passive mechanisms can be beneficial in enhancing the sustainability of microbial desalination cells.

Integrated pretreatment and desalination by electrocoagulation (EC)-ion concentration polarization (ICP) hybrid.

Science.gov (United States)

Choi, Siwon; Kim, Bumjoo; Han, Jongyoon

2017-06-13

Conventional water treatment process is composed of multiple stages, including desalination (salt removal) and pre/post-treatment of desalination to remove particles, chemicals, and other potential foulants for desalination. In this work, we developed a microfluidic proof-of-concept for a single device water treatment system, which removes both salt ions and non-salt contaminants. Our system combines electrocoagulation (EC), a versatile contaminant removal process, and ion concentration polarization (ICP) desalination, which is an electromembrane desalination process. We demonstrated a continuous EC-ICP operation that removed >95% of suspended solids and reduced the salinity from brackish range (20 mM NaCl) to a potable level (<8.6 mM NaCl). We also demonstrated that our system is flexible in terms of the type and concentration of contaminants it can handle. Combining two different electrochemical processes into a single system, we can reduce unnecessary voltage drop by having a shared anode, and achieve both seamless integration and energy efficient operation. Our system will find applications as a small-scale water treatment system, if properly scaled up in the future.

Performance of indigenously fabricated pyramid type solar desalination unit at Nawabshah

International Nuclear Information System (INIS)

Memon, A.H.; Rajpar, A.H.; Memon, N.A.

2010-01-01

The performance of locally fabricated pyramid type solar desalination unit was studied and compared with the conventional basin type solar still. Both stills were initially filled with same quantity of brackish water. Their performance was studied in terms of the quality of water produced, quantity of water desalinated per hour and total quantity of water desalinated per day during the time under study. The experiments were conducted and various parameters were recorded from 9-15 hours daily. These results showed that pyramid solar still produced 20% higher desalinated water as compared to the conventional double slope basin type solar still. This study showed that the productivity rate of soar still is dependent upon geometrical configuration of solar still. It was observed that the units can highly reduce the salinity, TDS (Total Dissolved Solids) and EC (Electrical Conductivity) of the saline ground water providing the availability of safe drinking water. (author)

Electrochemical desalination of salt infected limestone masonry of a historic warehouse

DEFF Research Database (Denmark)

Ottosen, Lisbeth M.; Christensen, Iben Vernegren; Rörig-Dalgaard, Inge

2012-01-01

plant for electrochemical desalination, a method where the driving force is an applied electrical potential. The test plant covered about 25 m2 surface of a limestone wall of a historic warehouse. It consisted of 72 electrode units which were placed in two rows; the one above the other and the mutual...... was successfully desalinated; however, the Cl concentration was in the same level as initially in samples taken just between sets of anodes and cathodes. The desalination was thus not completed during the test. The removal rate for Cl into the anodes was constant all through the test revealing...... that the desalination could have continued if the test had lasted longer. The test showed that the overall method works, but it also underlined the necessity for development of a new design, which allow for shorter distance between the electrodes in order to shorten the duration of the treatment....

Effectiveness of Humidification with Heat and Moisture Exchanger-booster in Tracheostomized Patients.

Science.gov (United States)

Gonzalez, Isabel; Jimenez, Pilar; Valdivia, Jorge; Esquinas, Antonio

2017-08-01

The two most commonly used types of humidifiers are heated humidifiers and heat and moisture exchange humidifiers. Heated humidifiers provide adequate temperature and humidity without affecting the respiratory pattern, but overdose can cause high temperatures and humidity resulting in condensation, which increases the risk of bacteria in the circuit. These devices are expensive. Heat and moisture exchanger filter is a new concept of humidification, increasing the moisture content in inspired gases. This study aims to determine the effectiveness of the heat and moisture exchanger (HME)-Booster system to humidify inspired air in patients under mechanical ventilation. We evaluated the humidification provided by 10 HME-Booster for tracheostomized patients under mechanical ventilation using Servo I respirators, belonging to the Maquet company and Evita 4. There was an increase in the inspired air humidity after 1 h with the humidifier. The HME-Booster combines the advantages of heat and moisture exchange minimizing the negatives. It increases the amount of moisture in inspired gas in mechanically ventilated tracheostomized patients. It is easy and safe to use. The type of ventilator used has no influence on the result.

Phase 3 Trial of Domiciliary Humidification to Mitigate Acute Mucosal Toxicity During Radiation Therapy for Head-and-Neck Cancer: First Report of Trans Tasman Radiation Oncology Group (TROG) 07.03 RadioHUM Study

International Nuclear Information System (INIS)

Macann, Andrew; Fua, Tsien; Milross, Chris G.; Porceddu, Sandro V.; Penniment, Michael; Wratten, Chris; Krawitz, Hedley; Poulsen, Michael; Tang, Colin I.; Morton, Randall P.; Hay, K. David; Thomson, Vicki; Bell, Melanie L.; King, Madeleine T.; Fraser-Browne, Carol L.; Hockey, Hans-Ulrich P.

2014-01-01

Purpose: To assess the impact of domicile-based humidification on symptom burden during radiation therapy (RT) for head-and-neck (H and N) cancer. Methods and Materials: From June 2007 through June 2011, 210 patients with H and N cancer receiving RT were randomized to either a control arm or to receive humidification using the Fisher and Paykel Healthcare MR880 humidifier. Humidification commenced on day 1 of RT and continued until Common Terminology Criteria for Adverse Events (CTCAE), version 3.0, clinical mucositis (CMuc) grade ≤1 occurred. Forty-three patients (42%) met a defined benchmark for humidification compliance and contributed to per protocol (PP) analysis. Acute toxicities, hospitalizations, and feeding tube events were recorded prospectively. The McMaster University Head and Neck Radiotherapy Questionnaire (HNRQ) was used for patient-reported outcomes. The primary endpoint was area under the curve (AUC) for CMuc grade ≥2. Results: There were no significant differences in AUC for CMuc ≥2 between the 2 arms. Humidification patients had significantly fewer days in hospital (P=.017). In compliant PP patients, the AUC for CTCAE functional mucositis score (FMuc) ≥2 was significantly reduced (P=.009), and the proportion who never required a feeding tube was significantly greater (P=.04). HNRQ PP analysis estimates also in the direction favoring humidification with less symptom severity, although differences at most time points did not reach significance. Conclusions: TROG 07.03 has provided efficacy signals consistent with a role for humidification in reducing symptom burden from mucositis, but the influence of humidification compliance on the results moderates recommendations regarding its practical utility

Phase 3 Trial of Domiciliary Humidification to Mitigate Acute Mucosal Toxicity During Radiation Therapy for Head-and-Neck Cancer: First Report of Trans Tasman Radiation Oncology Group (TROG) 07.03 RadioHUM Study

Energy Technology Data Exchange (ETDEWEB)

Macann, Andrew, E-mail: amacann@adhb.govt.nz [Department of Radiation Oncology, Auckland City Hospital, Auckland (New Zealand); Fua, Tsien [Department of Radiation Oncology, Peter MacCallum Cancer Centre, East Melbourne, Victoria (Australia); Milross, Chris G. [Department of Radiation Oncology, Royal Prince Alfred Hospital, Camperdown, New South Wales (Australia); Porceddu, Sandro V. [Oncology Services, Princess Alexandra Hospital, Woolloongabba, Queensland (Australia); Penniment, Michael [Radiation Oncology, Royal Adelaide Hospital, Adelaide, South Australia (Australia); Wratten, Chris [Radiation Oncology, Calvary Mater Newcastle, Waratah, New South Wales (Australia); Krawitz, Hedley [Department of Radiation Oncology, Auckland City Hospital, Auckland (New Zealand); Poulsen, Michael [Department of Radiation Oncology, Radiation Oncology Mater Centre, South Brisbane, Queensland (Australia); Tang, Colin I. [Department of Radiation Oncology, Sir Charles Gairdner Hospital, Nedlands, Western Australia (Australia); Morton, Randall P. [Department of Otorhinolaryngology, Middlemore Hospital, Otahuhu, Auckland (New Zealand); Hay, K. David [Department of Oral Health, Auckland City Hospital, Auckland (New Zealand); Thomson, Vicki [Department of Otorhinolaryngology, Auckland City Hospital, Auckland (New Zealand); Bell, Melanie L.; King, Madeleine T. [Psycho-oncology Cooperative Research Group, Univerity of Sydney, Sydney, New South Wales (Australia); Fraser-Browne, Carol L. [Adult Oncology Research Centre, Auckland City Hospital, Auckland (New Zealand); Hockey, Hans-Ulrich P. [Biometrics Matters Ltd, Hamilton (New Zealand)

2014-03-01

Purpose: To assess the impact of domicile-based humidification on symptom burden during radiation therapy (RT) for head-and-neck (H and N) cancer. Methods and Materials: From June 2007 through June 2011, 210 patients with H and N cancer receiving RT were randomized to either a control arm or to receive humidification using the Fisher and Paykel Healthcare MR880 humidifier. Humidification commenced on day 1 of RT and continued until Common Terminology Criteria for Adverse Events (CTCAE), version 3.0, clinical mucositis (CMuc) grade ≤1 occurred. Forty-three patients (42%) met a defined benchmark for humidification compliance and contributed to per protocol (PP) analysis. Acute toxicities, hospitalizations, and feeding tube events were recorded prospectively. The McMaster University Head and Neck Radiotherapy Questionnaire (HNRQ) was used for patient-reported outcomes. The primary endpoint was area under the curve (AUC) for CMuc grade ≥2. Results: There were no significant differences in AUC for CMuc ≥2 between the 2 arms. Humidification patients had significantly fewer days in hospital (P=.017). In compliant PP patients, the AUC for CTCAE functional mucositis score (FMuc) ≥2 was significantly reduced (P=.009), and the proportion who never required a feeding tube was significantly greater (P=.04). HNRQ PP analysis estimates also in the direction favoring humidification with less symptom severity, although differences at most time points did not reach significance. Conclusions: TROG 07.03 has provided efficacy signals consistent with a role for humidification in reducing symptom burden from mucositis, but the influence of humidification compliance on the results moderates recommendations regarding its practical utility.

Phase 3 trial of domiciliary humidification to mitigate acute mucosal toxicity during radiation therapy for head-and-neck cancer: first report of Trans Tasman Radiation Oncology Group (TROG) 07.03 RadioHUM study.

Science.gov (United States)

Macann, Andrew; Fua, Tsien; Milross, Chris G; Porceddu, Sandro V; Penniment, Michael; Wratten, Chris; Krawitz, Hedley; Poulsen, Michael; Tang, Colin I; Morton, Randall P; Hay, K David; Thomson, Vicki; Bell, Melanie L; King, Madeleine T; Fraser-Browne, Carol L; Hockey, Hans-Ulrich P

2014-03-01

To assess the impact of domicile-based humidification on symptom burden during radiation therapy (RT) for head-and-neck (H&N) cancer. From June 2007 through June 2011, 210 patients with H&N cancer receiving RT were randomized to either a control arm or to receive humidification using the Fisher & Paykel Healthcare MR880 humidifier. Humidification commenced on day 1 of RT and continued until Common Terminology Criteria for Adverse Events (CTCAE), version 3.0, clinical mucositis (CMuc) grade ≤1 occurred. Forty-three patients (42%) met a defined benchmark for humidification compliance and contributed to per protocol (PP) analysis. Acute toxicities, hospitalizations, and feeding tube events were recorded prospectively. The McMaster University Head and Neck Radiotherapy Questionnaire (HNRQ) was used for patient-reported outcomes. The primary endpoint was area under the curve (AUC) for CMuc grade ≥2. There were no significant differences in AUC for CMuc ≥2 between the 2 arms. Humidification patients had significantly fewer days in hospital (P=.017). In compliant PP patients, the AUC for CTCAE functional mucositis score (FMuc) ≥2 was significantly reduced (P=.009), and the proportion who never required a feeding tube was significantly greater (P=.04). HNRQ PP analysis estimates also in the direction favoring humidification with less symptom severity, although differences at most time points did not reach significance. TROG 07.03 has provided efficacy signals consistent with a role for humidification in reducing symptom burden from mucositis, but the influence of humidification compliance on the results moderates recommendations regarding its practical utility. Copyright © 2014 Elsevier Inc. All rights reserved.

Nanotechnology applications to desalination : a report for the joint water reuse & desalination task force.

Energy Technology Data Exchange (ETDEWEB)

Brady, Patrick Vane; Mayer, Tom; Cygan, Randall Timothy

2011-01-01

Nanomaterials and nanotechnology methods have been an integral part of international research over the past decade. Because many traditional water treatment technologies (e.g. membrane filtration, biofouling, scale inhibition, etc.) depend on nanoscale processes, it is reasonable to expect one outcome of nanotechnology research to be better, nano-engineered water treatment approaches. The most immediate, and possibly greatest, impact of nanotechnology on desalination methods will likely be the development of membranes engineered at the near-molecular level. Aquaporin proteins that channel water across cell membranes with very low energy inputs point to the potential for dramatically improved performance. Aquaporin-laced polymer membranes and aquaporin-mimicking carbon nanotubes and metal oxide membranes developed in the lab support this. A critical limitation to widespread use of nanoengineered desalination membranes will be their scalability to industrial fabrication processes. Subsequent, long-term improvements in nanoengineered membranes may result in self-healing membranes that ideally are (1) more resistant to biofouling, (2) have biocidal properties, and/or (3) selectively target trace contaminants.

Nuclear's potential role in desalination

International Nuclear Information System (INIS)

Kupitz, J.

1992-01-01

Motivated by the growing need for fresh water in developing countries, the International Atomic Energy Agency (IAEA) has promoted a study of the technical and economic viability of using nuclear energy for producing fresh water by desalination of seawater. The outcome of the study is summarized. The most promising desalination processes for large scale water production are outlined and possible energy sources considered. The main incentives for using nuclear energy rather than fossil fuelled plants include: overall energy supply diversification; conservation of limited fossil fuel resources; promotion of technological development; and in particular, environmental protection through the reduction of emissions causing climate change and acid rain. An economic analysis showed that the levelized costs of electricity generation by nuclear power are in general in the same range as those for fossil fuel. Competitiveness depends on the unit size of the plant and interest rates. (UK)

Economic feasibility of a solar still desalination system with enhanced productivity

KAUST Repository

Ayoub, George M.

2014-02-01

Solar still desalination systems offer sustainable tools for fresh water production. However, their widespread application is often hindered by their relatively low production rates compared to other desalination methods. In this study, a simple amendment, in the form of a slowly-rotating hollow cylinder, was introduced within the solar still, significantly increasing the evaporative surface area. This new modified still was analyzed in terms of both operation and economic feasibility. The introduced cylinder resulted in a 200-300% increase in water output relative to a control, which did not include the cylinder. The resulting percent improvement far exceeds that obtained by other modifications. Unit production cost estimates varied between 6 and 60$/m3 depending on discount rates, productivity, service lifetime and initial capital costs. These projections are well within reported cost ranges for renewable-based technologies. In order to evaluate the system\\'s feasibility in real market value, different scenarios that introduce carbon-trading schemes and environmental degradation costs for fuel-based desalination, were performed. Reported costs for fuel-based brackish water and seawater desalination were thus adjusted to include unaccounted-for costs related to environmental damage. This analysis yielded results that further justify the economic feasibility of the new modified solar still, particularly for seawater desalination. © 2013 Elsevier B.V.

Model-based Extracted Water Desalination System for Carbon Sequestration

Energy Technology Data Exchange (ETDEWEB)

Gettings, Rachel; Dees, Elizabeth

2017-03-23

The focus of this research effort centered around water recovery from high Total Dissolved Solids (TDS) extracted waters (180,000 mg/L) using a combination of water recovery (partial desalination) technologies. The research goals of this project were as follows: 1. Define the scope and test location for pilot-scale implementation of the desalination system, 2.Define a scalable, multi-stage extracted water desalination system that yields clean water, concentrated brine, and, salt from saline brines, and 3. Validate overall system performance with field-sourced water using GE pre-pilot lab facilities. Conventional falling film-mechanical vapor recompression (FF-MVR) technology was established as a baseline desalination process. A quality function deployment (QFD) method was used to compare alternate high TDS desalination technologies to the base case FF-MVR technology, including but not limited to: membrane distillation (MD), forward osmosis (FO), and high pressure reverse osmosis (HPRO). Technoeconomic analysis of high pressure reverse osmosis (HPRO) was performed comparing the following two cases: 1. a hybrid seawater RO (SWRO) plus HPRO system and 2. 2x standard seawater RO system, to achieve the same total pure water recovery rate. Pre-pilot-scale tests were conducted using field production water to validate key process steps for extracted water pretreatment. Approximately 5,000 gallons of field produced water was processed through, microfiltration, ultrafiltration, and steam regenerable sorbent operations. Improvements in membrane materials of construction were considered as necessary next steps to achieving further improvement in element performance at high pressure. Several modifications showed promising results in their ability to withstand close to 5,000 PSI without gross failure.

Desalination Economic Evaluation Program (DEEP-3.0). User's manual

International Nuclear Information System (INIS)

2006-01-01

DEEP is a Desalination Economic Evaluation Program developed by the International Atomic Energy Agency (IAEA) and made freely available for download, under a license agreement (www.iaea.org/nucleardesalination). The program is based on linked Microsoft Excel spreadsheets and can be useful for evaluating desalination strategies by calculating estimates of technical performance and costs for various alternative energy and desalination technology configurations. Desalination technology options modelled, include multi-stage flashing (MSF), multi-effect distillation (MED), reverse osmosis (RO) and hybrid options (RO-MSF, RO-MED) while energy source options include nuclear, fossil, renewables and grid electricity (stand-alone RO). Version 3 of DEEP (DEEP 3.0) features important changes from previous versions, including upgrades in thermal and membrane performance and costing models, the coupling configuration matrix and the user interface. Changes in the thermal performance model include a revision of the gain output ratio (GOR) calculation and its generalization to include thermal vapour compression effects. Since energy costs continue to represent an important fraction of seawater desalination costs, the lost shaft work model has been generalized to properly account for both backpressure and extraction systems. For RO systems, changes include improved modelling of system recovery, feed pressure and permeate salinity, taking into account temperature, feed salinity and fouling correction factors. The upgrade to the coupling technology configuration matrix includes a re-categorization of the energy sources to follow turbine design (steam vs. gas) and cogeneration features (dual-purpose vs. heat-only). In addition, cost data has also been updated to reflect current practice and the user interface has been refurbished and made user-friendlier

IDA world congress on desalination and water reuse, october 6-9, 1997, Madrid

Energy Technology Data Exchange (ETDEWEB)

International desalination association

1997-12-31

The books contain the Congress on Desalination and water reuse held in Madrid during October 1997. The five volumen present the following scopes. 1.- Fresh water world and Regional prospective 2.- Membrane desalination design 3. -Evaporative desalination operational experience 4.- Potable water reuse 5.- Plant automation design and experience 6.- Materials and corrosion research 7.- Chemistry and pretreatment. 8.- Research and development review 9.- Water treatment and potabilitation

Desalinated drinking water in the GCC countries - The need to address consumer perceptions.

Science.gov (United States)

Shomar, Basem; Hawari, Jalal

2017-10-01

The Gulf Cooperation Council (GCC) countries consist of Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, and the United Arab Emirates. These countries depend mainly on seawater desalination to meet their water needs. Although great emphasis is given to characterize desalinated water for its physicochemical and microbial properties, e.g. presence of metals, other organic contaminants and for bacteria, sensorial characteristics including smell, taste and color have not received the same attention. This is possibly attributed to the fact that inhabitants of GCC States do not use desalinated tap water for drinking consumption, rather they depend on locally produced or imported bottled water where color, taste and odor are not problematic. To address the consumer needs and perceptions of drinking desalinated water in GCC countries, water quality standards and guidelines, should respond to the public concern about other sensorial characteristics (organoleptic properties) including taste, odor, and trigeminal sensations. Often the root causes of color and smell in water are attributed to the presence of organic and inorganic contaminants and to bacterial growth which is frequently accompanied by the production of metabolites and byproducts that are obnoxious. The unpleasant sensorial problems associated with desalinated drinking tap water may constitute the driving force for most people in GCC countries to depend on bottled water. To encourage people in the GCC countries to consume desalinated tap water, it is essential that water testing include measurements of physicochemical properties, biofilm presence and organoleptic parameters to improve overall water quality. This review highlights the contribution of organoleptics for consumers of desalinated tap water. It extends water quality research to be addressed by standards for organoleptic parameters in desalinated drinking water. Accordingly, consumer awareness and outreach campaigns should be implemented to encourage people

Economic evaluation of the integrated SMART desalination plant

International Nuclear Information System (INIS)

Hwang, Young Dong; Lee, Man Kye; Yeo, Ji Won; Kim, Hee Chul; Chang, Moon Hee

2001-04-01

In this study, an economic evaluation methodology of the integrated SMART desalination plant was established and the economic evaluation of SMART was performed. The plant economics was evaluated with electricity generation costs calculated using approximate estimates of SMART cost data and the result was compared with the result calculated using the SMART design data and estimated bulk materials. In addition, a series of sensitivity studies on the power generation cost was performed for the main economic parameters of SMART Power credit method was used for the economic analysis of the integrated SMART desalination plant. Power credit method is a widely used economic analysis method for the cogeneration plant when the major portion of the energy is used for the electricity generation. In the case of using SMART fot power generation only, the result shows that the electricity generation cost of SMART is higher than that of the alternative power options. However, it can be competitive with the other power options in the limited cases, especially with the gas fired combined plant. In addition, an economic analysis of the integrated SMART desalination plant coupled with MED was performed. The calculated water production cost is in the range of 0.56 approx. 0.88($/m 3 ) for the plant availability of 80% or higher, which is close to the study results presented by the various other countries. This indicates that SMART can be considered as a competitive choice for desalination among various alternative energy sources

Economic evaluation of the integrated SMART desalination plant

Energy Technology Data Exchange (ETDEWEB)

Hwang, Young Dong; Lee, Man Kye; Yeo, Ji Won; Kim, Hee Chul; Chang, Moon Hee

2001-04-01

In this study, an economic evaluation methodology of the integrated SMART desalination plant was established and the economic evaluation of SMART was performed. The plant economics was evaluated with electricity generation costs calculated using approximate estimates of SMART cost data and the result was compared with the result calculated using the SMART design data and estimated bulk materials. In addition, a series of sensitivity studies on the power generation cost was performed for the main economic parameters of SMART Power credit method was used for the economic analysis of the integrated SMART desalination plant. Power credit method is a widely used economic analysis method for the cogeneration plant when the major portion of the energy is used for the electricity generation. In the case of using SMART fot power generation only, the result shows that the electricity generation cost of SMART is higher than that of the alternative power options. However, it can be competitive with the other power options in the limited cases, especially with the gas fired combined plant. In addition, an economic analysis of the integrated SMART desalination plant coupled with MED was performed. The calculated water production cost is in the range of 0.56 approx. 0.88($/m{sup 3}) for the plant availability of 80% or higher, which is close to the study results presented by the various other countries. This indicates that SMART can be considered as a competitive choice for desalination among various alternative energy sources.

Heated humidification versus heat and moisture exchangers for ventilated adults and children.

Science.gov (United States)

Kelly, Margaret; Gillies, Donna; Todd, David A; Lockwood, Catherine

2010-10-01

Humidification by artificial means must be provided when the upper airway is bypassed during mechanical ventilation. Heated humidification (HH) and heat and moisture exchangers (HMEs) are the most commonly used types of artificial humidification in this situation. To determine whether HHs or HMES are more effective in preventing mortality and other complications in people who are mechanically ventilated. We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library 2010, Issue 4) and MEDLINE, EMBASE and CINAHL (January, 2010) to identify relevant randomized controlled trials. We included randomized controlled trials comparing HMEs to HHs in mechanically ventilated adults and children. We included randomized crossover studies. We assessed the quality of each study and extracted the relevant data. Where appropriate, results from relevant studies were meta-analyzed for individual outcomes. We included 33 trials with 2833 participants; 25 studies were parallel group design (n = 2710) and 8 crossover design (n = 123). Only 3 included studies reported data for infants or children. There was no overall effect on artificial airway occlusion, mortality, pneumonia, or respiratory complications; however, the PaCO(2) and minute ventilation were increased when HMEs were compared to HHs and body temperature was lower. The cost of HMEs was lower in all studies that reported this outcome. There was some evidence that hydrophobic HMEs may reduce the risk of pneumonia and that blockages of artificial airways may be increased with the use of HMEs in certain subgroups of patients. There is little evidence of an overall difference between HMEs and HHs. However, hydrophobic HMEs may reduce the risk of pneumonia and the use of an HMEs may increase artificial airway occlusion in certain subgroups of patients. Therefore, HMEs may not be suitable for patients with limited respiratory reserve or prone to airway blockage. Further research is needed relating to

Potential for nuclear desalination as a source of low cost potable water in North Africa

International Nuclear Information System (INIS)

1996-11-01

Based on the limited regional water resources and in recognizing the possible role of nuclear energy in seawater desalination, the five North African Countries (NACs): Algeria, Egypt, Libya, Morocco and Tunisia submitted a request to the IAEA in 1990 for assistance in carrying out a feasibility study on the use of nuclear energy for seawater desalination in some pre-selected sites in these countries to cover their medium- and long-term needs for economical potable water. The present report has been prepared and is presented to the NACs in response to their request. It contains an assessment of the regional specific aspects, the available technical options with respect to desalination processes and energy sources, the cost evaluation of various technical options for the production of desalinated water, as well as the financial constraints and options, and finally the necessary steps needed to ensure the successful implementation of a nuclear desalination programme. The report also complements other work of the IAEA in the field of nuclear desalination, carried out in response to various resolutions of the IAEA General Conferences since 1989, namely: ''Use of Nuclear Reactors for Seawater Desalination'', IAEA-TECDOC-574 (1990) and ''Technical and Economic Evaluation of Potable Water Production through Desalination of Seawater by using Nuclear Energy and Other Means'', IAEA-TECDOC-666 (1992). 105 refs, 39 figs, tabs

Potential for nuclear desalination as a source of low cost potable water in North Africa

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-11-01

Based on the limited regional water resources and in recognizing the possible role of nuclear energy in seawater desalination, the five North African Countries (NACs): Algeria, Egypt, Libya, Morocco and Tunisia submitted a request to the IAEA in 1990 for assistance in carrying out a feasibility study on the use of nuclear energy for seawater desalination in some pre-selected sites in these countries to cover their medium- and long-term needs for economical potable water. The present report has been prepared and is presented to the NACs in response to their request. It contains an assessment of the regional specific aspects, the available technical options with respect to desalination processes and energy sources, the cost evaluation of various technical options for the production of desalinated water, as well as the financial constraints and options, and finally the necessary steps needed to ensure the successful implementation of a nuclear desalination programme. The report also complements other work of the IAEA in the field of nuclear desalination, carried out in response to various resolutions of the IAEA General Conferences since 1989, namely: ``Use of Nuclear Reactors for Seawater Desalination``, IAEA-TECDOC-574 (1990) and ``Technical and Economic Evaluation of Potable Water Production through Desalination of Seawater by using Nuclear Energy and Other Means``, IAEA-TECDOC-666 (1992). 105 refs, 39 figs, tabs.

Conditions of competition between the production of water by desalination and natural resources

International Nuclear Information System (INIS)

Gaussens, J.

1969-01-01

A close examination of the local supply and demand for fresh water is involved when considering a sea water desalination plant in a given region. This examination makes it possible in most cases to undertake a thorough study of the natural resources, resulting in the use of desalination being rejected. After confirming this fact by precise examples, the authors consider that the preliminary study should be extended, taking into account the complementary character of natural resources and desalination systems: contribution to peak demand, contribution to base demand. This analysis results in a classification of the main user regions according to certain economic criteria defining their suitability for the use of desalination processes. (author) [fr

A conceptual demonstration of freeze desalination-membrane distillation (FD-MD) hybrid desalination process utilizing liquefied natural gas (LNG) cold energy.

Science.gov (United States)

Wang, Peng; Chung, Tai-Shung

2012-09-01

The severe global water scarcity and record-high fossil oil price have greatly stimulated the research interests on new desalination technologies which can be driven by renewable energy or waste energy. In this study, a hybrid desalination process comprising freeze desalination and membrane distillation (FD-MD) processes was developed and explored in an attempt to utilize the waste cold energy released from re-gasification of liquefied natural gas (LNG). The concept of this technology was demonstrated using indirect-contact freeze desalination (ICFD) and direct-contact membrane distillation (DCMD) configurations. By optimizing the ICFD operation parameters, namely, the usage of nucleate seeds, operation duration and feed concentration, high quality drinkable water with a low salinity ∼0.144 g/L was produced in the ICFD process. At the same time, using the optimized hollow fiber module length and packing density in the DCMD process, ultra pure water with a low salinity of 0.062 g/L was attained at a condition of high energy efficiency (EE). Overall, by combining FD and MD processes and adopting the optimized operation parameters, the hybrid FD-MD system has been successfully demonstrated. A high total water recovery of 71.5% was achieved, and the water quality obtained met the standard for drinkable water. In addition, with results from specific energy calculation, it was proven that the hybrid process is an energy-saving process and utilization of LNG cold energy could greatly reduce the total energy consumption. Copyright © 2012 Elsevier Ltd. All rights reserved.

A seawater desalination scheme for global hydrological models

Science.gov (United States)

Hanasaki, Naota; Yoshikawa, Sayaka; Kakinuma, Kaoru; Kanae, Shinjiro

2016-10-01

Seawater desalination is a practical technology for providing fresh water to coastal arid regions. Indeed, the use of desalination is rapidly increasing due to growing water demand in these areas and decreases in production costs due to technological advances. In this study, we developed a model to estimate the areas where seawater desalination is likely to be used as a major water source and the likely volume of production. The model was designed to be incorporated into global hydrological models (GHMs) that explicitly include human water usage. The model requires spatially detailed information on climate, income levels, and industrial and municipal water use, which represent standard input/output data in GHMs. The model was applied to a specific historical year (2005) and showed fairly good reproduction of the present geographical distribution and national production of desalinated water in the world. The model was applied globally to two periods in the future (2011-2040 and 2041-2070) under three distinct socioeconomic conditions, i.e., SSP (shared socioeconomic pathway) 1, SSP2, and SSP3. The results indicate that the usage of seawater desalination will have expanded considerably in geographical extent, and that production will have increased by 1.4-2.1-fold in 2011-2040 compared to the present (from 2.8 × 109 m3 yr-1 in 2005 to 4.0-6.0 × 109 m3 yr-1), and 6.7-17.3-fold in 2041-2070 (from 18.7 to 48.6 × 109 m3 yr-1). The estimated global costs for production for each period are USD 1.1-10.6 × 109 (0.002-0.019 % of the total global GDP), USD 1.6-22.8 × 109 (0.001-0.020 %), and USD 7.5-183.9 × 109 (0.002-0.100 %), respectively. The large spreads in these projections are primarily attributable to variations within the socioeconomic scenarios.

Optimal scheduling of biocide dosing for seawater-cooled power and desalination plants

KAUST Repository

Mahfouz, Abdullah Bin; Atilhan, Selma; Batchelor, Bill; Linke, Patrick; Abdel-Wahab, Ahmed; El-Halwagi, Mahmoud M.

2011-01-01

Thermal desalination systems are typically integrated with power plants to exploit the excess heat resulting from the power-generation units. Using seawater in cooling the power plant and the desalination system is a common practice in many parts

Desalination of painted brick vaults

DEFF Research Database (Denmark)

Larsen, Poul Klenz

The subject of the thesis is salt and moisture movement that causes damage to wall paintings on church vaults. The deterioration was studied in the churches of Fanefjord, Kirkerup and Brarup. A desalination method was tested om location. The salt and moisture transfer was examined in detail...

Thermodynamic cycles of adsorption desalination system

International Nuclear Information System (INIS)

Wu, Jun W.; Hu, Eric J.; Biggs, Mark J.

2012-01-01

Highlights: ► Thermodynamic cycles of adsorption desalination (AD) system have been identified all possible evaporator temperature scenarios. ► Temperature of evaporator determines the cycle. ► Higher evaporator temperature leads to higher water production if no cooling is required. -- Abstract: The potential to use waste heat to co-generate cooling and fresh water from saline water using adsorption on silica is attracting increasing attention. A variety of different thermodynamic cycles of such an adsorption desalination (AD) system arise as the temperature of the saline water evaporator is varied relative to temperature of the water used to cool the adsorbent as it adsorbs the evaporated water. In this paper, all these possible thermodynamic cycles are enumerated and analysed to determine their relative performances in terms of specific energy consumption and fresh water productivity.

A multi evaporator desalination system operated with thermocline energy for future sustainability

KAUST Repository

Shahzad, Muhammad Wakil; Burhan, Muhammad; Ghaffour, NorEddine; Ng, Kim Choon

2017-01-01

) of desalination is at 828. Despite slightly better UPRs for the RO plants, all practical desalination plants available, hitherto, operate at only less than 12% of the TL, rendering them highly energy intensive and unsustainable for future sustainability. More

Coupling of RO-MSF hybrid desalination plants with nuclear reactors

International Nuclear Information System (INIS)

Al-Sulaiman, Khalil; Al-Mutaz, Ibrahim S.

1999-01-01

Full text.Reverse osmosis (RO) and multistage flash (MSF) desalination are the most widely commercial available processes. MSF utilizes stream in the brine heater as a primary source of energy. RO is derived mainly by electricity that pumps the feed water against the mambranes. Steam and electricity and be produced easily by nuclear reactors. Nuclear reactors may be coupled with deslination plants (MSF, RO or combined (hybrid) RO/MSF configuration). This integrated plant will be capable of producing power and water at reasonable cost. The capital and operating cost will be reduced and the excess power can be efficiently utilized. Maintenance and operating cost will drop significantly. In this paper, a techno-economic study of hybrid reverses osmosis /multistage flash desalination will be carried. The proposed configuration (hybrid RO/MSF) coupled with nuclear reactor is considered the most appropriate candidate system for the application of dual-purpose nuclear desalination plants. the design parameters for such a desalination hybrid system will be the applied pressure and recovery for reverse osmosis plant and the number of stages and the heat transfer areas for multistage flash plant

Desalination and reuse of high-salinity shale gas produced water: drivers, technologies, and future directions.

Science.gov (United States)

Shaffer, Devin L; Arias Chavez, Laura H; Ben-Sasson, Moshe; Romero-Vargas Castrillón, Santiago; Yip, Ngai Yin; Elimelech, Menachem

2013-09-03

In the rapidly developing shale gas industry, managing produced water is a major challenge for maintaining the profitability of shale gas extraction while protecting public health and the environment. We review the current state of practice for produced water management across the United States and discuss the interrelated regulatory, infrastructure, and economic drivers for produced water reuse. Within this framework, we examine the Marcellus shale play, a region in the eastern United States where produced water is currently reused without desalination. In the Marcellus region, and in other shale plays worldwide with similar constraints, contraction of current reuse opportunities within the shale gas industry and growing restrictions on produced water disposal will provide strong incentives for produced water desalination for reuse outside the industry. The most challenging scenarios for the selection of desalination for reuse over other management strategies will be those involving high-salinity produced water, which must be desalinated with thermal separation processes. We explore desalination technologies for treatment of high-salinity shale gas produced water, and we critically review mechanical vapor compression (MVC), membrane distillation (MD), and forward osmosis (FO) as the technologies best suited for desalination of high-salinity produced water for reuse outside the shale gas industry. The advantages and challenges of applying MVC, MD, and FO technologies to produced water desalination are discussed, and directions for future research and development are identified. We find that desalination for reuse of produced water is technically feasible and can be economically relevant. However, because produced water management is primarily an economic decision, expanding desalination for reuse is dependent on process and material improvements to reduce capital and operating costs.

Technical and economic assessment of photovoltaic-driven desalination systems

International Nuclear Information System (INIS)

Al-Karaghouli, Ali; Renne, David; Kazmerski, Lawrence L.

2010-01-01

Solar desalination systems are approaching technical and cost viability for producing fresh-water, a commodity of equal importance to energy in many arid and coastal regions worldwide. Solar photovoltaics (PV) represent an ideal, clean alternative to fossil fuels, especially for remote communities such as grid-limited villages or isolated islands. These applications for water production in remote areas are the first to be nearing cost-competitiveness due to decreasing PV prices and increasing fossil fuel prices over the last five years. The electricity produced from PV systems for desalination applications can be used for electro-mechanical devices such as pumps or in direct-current (DC) devices. Reverse osmosis (RO) and electrodialysis (ED) desalination units are the most favorable alternatives to be coupled with PV systems. RO usually operates on alternating current (AC) for the pumps, thus requiring a DC/AC inverter. In contrast, electrodialysis uses DC for the electrodes at the cell stack, and hence, it can use the energy supplied from the PV panels with some minor power conditioning. Energy storage is critical and batteries are required for sustained operation. In this paper, we discuss the operational features and system designs of typical PV-RO and PV-ED systems in terms of their suitability and optimization for PV operation. For PV-RO and PV-ED systems, we evaluate their electricity need, capital and operational costs, and fresh-water production costs. We cover ongoing and projected research and development activities, with estimates of their potential economics. We discuss the feasibility of future solar desalination based on expected (or predicted) improvements in technology of the desalination and PV systems. Examples are provided for Middle East and other parts of the World. (author)

Microbial Electrodialysis Cell for Simultaneous Water Desalination and Hydrogen Gas Production

KAUST Repository

Mehanna, Maha

2010-12-15

A new approach to water desalination is to use exoelectrogenic bacteria to generate electrical power from the biodegradation of organic matter, moving charged ions from a middle chamber between two membranes in a type of microbial fuel cell called a microbial desalination cell. Desalination efficiency using this approach is limited by the voltage produced by the bacteria. Here we examine an alternative strategy based on boosting the voltage produced by the bacteria to achieve hydrogen gas evolution from the cathode using a three-chambered system we refer to as a microbial electrodialysis cell (MEDC). We examined the use of the MEDC process using two different initial NaCl concentrations of 5 g/L and 20 g/L. Conductivity in the desalination chamber was reduced by up to 68 ± 3% in a single fed-batch cycle, with electrical energy efficiencies reaching 231 ± 59%, and maximum hydrogen production rates of 0.16 ± 0.05 m3 H2/m3 d obtained at an applied voltage of 0.55 V. The advantage of this system compared to a microbial fuel cell approach is that the potentials between the electrodes can be better controlled, and the hydrogen gas that is produced can be used to recover energy to make the desalination process self-sustaining with respect to electrical power requirements. © 2010 American Chemical Society.

Microbial Electrodialysis Cell for Simultaneous Water Desalination and Hydrogen Gas Production

KAUST Repository

Mehanna, Maha; Kiely, Patrick D.; Call, Douglas F.; Logan, Bruce. E.

2010-01-01

A new approach to water desalination is to use exoelectrogenic bacteria to generate electrical power from the biodegradation of organic matter, moving charged ions from a middle chamber between two membranes in a type of microbial fuel cell called a microbial desalination cell. Desalination efficiency using this approach is limited by the voltage produced by the bacteria. Here we examine an alternative strategy based on boosting the voltage produced by the bacteria to achieve hydrogen gas evolution from the cathode using a three-chambered system we refer to as a microbial electrodialysis cell (MEDC). We examined the use of the MEDC process using two different initial NaCl concentrations of 5 g/L and 20 g/L. Conductivity in the desalination chamber was reduced by up to 68 ± 3% in a single fed-batch cycle, with electrical energy efficiencies reaching 231 ± 59%, and maximum hydrogen production rates of 0.16 ± 0.05 m3 H2/m3 d obtained at an applied voltage of 0.55 V. The advantage of this system compared to a microbial fuel cell approach is that the potentials between the electrodes can be better controlled, and the hydrogen gas that is produced can be used to recover energy to make the desalination process self-sustaining with respect to electrical power requirements. © 2010 American Chemical Society.

Renewable energy-driven desalination technologies: A comprehensive review on challenges and potential applications of integrated systems

KAUST Repository

Ghaffour, Noreddine

2015-01-01

Despite the tremendous improvements in conventional desalination technologies, its wide use is still limited due primarily to high energy requirements which are currently met with expensive fossil fuels. The use of alternative energy sources is essential to meet the growing demand for water desalination. In the last few decades a lot of effort has being directed in the use of different renewable energy (RE) sources to run desalination processes. However, the expansion of these efforts towards larger scale plants is hampered by several techno-economic challenges. Several medium-scale RE-driven desalination plants have been installed worldwide. Nevertheless, most of these plants are connected to the electrical grid to assure a continuous energy supply for stable operation. Furthermore, RE is mostly used to produce electric power which can be used to run desalination systems. This review paper focuses on an integrated approach in using RE-driven with an emphasis on solar and geothermal desalination technologies. Innovative and sustainable desalination processes which are suitable for integrated RE systems are presented. An assessment of the benefits of these technologies and their limitations are also discussed.

Optimum design of cogeneration system for nuclear seawater desalination - 15272

International Nuclear Information System (INIS)

Jung, Y.H.; Jeong, Y.H.

2015-01-01

A nuclear desalination process, which uses the energy released by nuclear fission, has less environmental impact and is generally cost-competitive with a fossil-fuel desalination process. A reference cogeneration system focused on in this study is the APR-1400 coupled with a MED (multi-effect distillation) process using the thermal vapor compression (TVC) technology. The thermal condition of the heat source is the most crucial factor that determines the desalination performance, i.e. energy consumption or freshwater production, of the MED-TVC process. The MED-TVC process operating at a higher motive steam pressure clearly shows a higher desalination performance. However, this increased performance does not necessarily translate to an advantage over processes operated at lower motive steam pressures. For instance, a higher motive steam pressure will increase the heat cost resulting from larger electricity generation loss, and thus may make this process unfavorable from an economic point of view. Therefore, there exists an optimum design point in the coupling configuration that makes the nuclear cogeneration system the most economical. This study is mainly aimed at investigating this optimum coupling design point of the reference nuclear cogeneration system using corresponding analysis tools. The following tools are used: MEE developed by the MEDRC for desalination performance analysis of the MED-TVC process, DE-TOP and DEEP developed by the IAEA for modeling of coupling configuration and economic evaluation of the nuclear cogeneration system, respectively. The results indicate that steam extraction from the MS exhaust and condensate return to HP FWHTR 5 is the most economical coupling design

Reasons for the Fast Growing Seawater Desalination Capacity in Algeria

KAUST Repository

Drouiche, Nadjib

2011-05-24

Seawater/brackish water desalination has been widely adopted by the Algerian Government in the last few years to supply potable water to municipality for various purposes mainly for domestic and industrial uses especially in areas where demand is high due to shortage of fresh water resources, rapid population growth and development of industry and tourism. Ten years ago, desalination was confined to the industrial use only especially in oil and gas industry as the country was relying on rain water and other available sources to supply fresh water to municipalities. Due to chronic drought conditions, the Ministry of Water Resources reviewed the national water strategy and a strong option for desalination was adopted where an ambitious program was thus put into action. Sixteen mega-plants, with capacities ranging from 100,000 to 500,000 m3 per day, primarily based on Reverse Osmosis technology, were launched in the last few years making the Algerian desalination program one of the world\\'s fastest growing markets. Five desalination plants, including the Africa\\'s largest seawater reverse osmosis project with a total capacity of 200,000 m3 per day, are already in operation and the remaining projects are either under construction or in commissioning. An integrated water resources management was also adopted as additional option to cuter the increasing water demand as there is also a great potential for water reuse and conventional water treatment. An additional benefit of this would be reducing the volume of treated wastewater disposed into the environment. © 2011 Springer Science+Business Media B.V.

Integrating Desalination and Energy Storage using a Saltwater-based Hybrid Sodium-ion Supercapacitor.

Science.gov (United States)

Guo, Zhaowei; Ma, Yuanyuan; Dong, Xiaoli; Hou, Mengyan; Wang, Yonggang; Xia, Yongyao

2018-06-11

Ever-increasing freshwater scarcity and energy crisis problems require efficient seawater desalination and energy storage technologies; however, each target is generally considered separately. Herein, a hybrid sodium-ion supercapacitor, involving a carbon-coated nano-NaTi 2 (PO 4 ) 3 -based battery anode and an activated-carbon-based capacitive cathode, is developed to combine desalination and energy storage in one device. On charge, the supercapacitor removes salt in a flowing saltwater electrolyte through Cl - electrochemical adsorption at the cathode and Na + intercalation at the anode. Discharge delivers useful electric energy and regenerates the electrodes. This supercapacitor can be used not only for energy storage with promising electrochemical performance (i.e., high power, high efficiency, and long cycle life), but also as a desalination device with desalination capacity of 146.8 mg g -1 , much higher than most reported capacitive and battery desalination devices. Finally, we demonstrate renewables to usable electric energy and desalted water through combining commercial photovoltaics and this hybrid supercapacitor. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Water desalination using different capacity reactors options

International Nuclear Information System (INIS)

Alonso, G.; Vargas, S.; Del Valle, E.; Ramirez, R.

2010-01-01

The Northwest region of Mexico has a deficit of potable water, along this necessity is the region growth, which requires of additional energy capacity, cogeneration of potable water production and nuclear electricity is an option to be assessed. In this paper we will perform an economical comparison for cogeneration using a big reactor, the AP1000, and a medium size reactor, the IRIS, both of them are PWR type reactors and will be coupled to the desalination plant using the same method. For this cogeneration case we will assess the best reactor option that can cover both needs using the maximum potable water production for two different desalination methods: Multistage Flash Distillation and Multi-effect Distillation. (authors)

Indirect economic impacts in water supplies augmented with desalinated water

DEFF Research Database (Denmark)

Rygaard, Martin; Arvin, Erik; Binning, Philip John

2010-01-01

Several goals can be considered when optimizing blends from multiple water resources for urban water supplies. Concentration-response relationships from the literature indicate that a changed water quality can cause impacts on health, lifetime of consumer goods and use of water additives like...... going from fresh water based to desalinated water supply. Large uncertainties prevent the current results from being used for or against desalination as an option for Copenhagen's water supply. In the future, more impacts and an uncertainty analysis will be added to the assessment....... softeners. This paper describes potential economic consequences of diluting Copenhagen's drinking water with desalinated water. With a mineral content at 50% of current levels, dental caries and cardiovascular diseases are expected to increase by 51 and 23% respectively. Meanwhile, the number of dish...

Apparatus and method for improved desalination

KAUST Repository

Ng, Kim Choon; Thu, Kyaw; Hideharu, Yanagi; Saha, Bidyut Baran; Chakraborty, Anutosh; Al-Ghasham, Tawfiq

2009-01-01

A water desalination system comprising an evaporator for evaporating saline water to produce water vapor; a condenser for condensing the water vapor; wherein the evaporator and the condenser are in heat transfer communication such that heat used

Humidification performance of humidifying devices for tracheostomized patients with spontaneous breathing: a bench study.

Science.gov (United States)

Chikata, Yusuke; Oto, Jun; Onodera, Mutsuo; Nishimura, Masaji

2013-09-01

Heat and moisture exchangers (HMEs) are commonly used for humidifying respiratory gases administered to mechanically ventilated patients. While they are also applied to tracheostomized patients with spontaneous breathing, their performance in this role has not yet been clarified. We carried out a bench study to investigate the effects of spontaneous breathing parameters and oxygen flow on the humidification performance of 11 HMEs. We evaluated the humidification provided by 11 HMEs for tracheostomized patients, and also by a system delivering high-flow CPAP, and an oxygen mask with nebulizer heater. Spontaneous breathing was simulated with a mechanical ventilator, lung model, and servo-controlled heated humidifier at tidal volumes of 300, 500, and 700 mL, and breathing frequencies of 10 and 20 breaths/min. Expired gas was warmed to 37°C. The high-flow CPAP system was set to deliver 15, 30, and 45 L/min. With the 8 HMEs that were equipped with ports to deliver oxygen, and with the high-flow CPAP system, measurements were taken when delivering 0 and 3 L/min of dry oxygen. After stabilization we measured the absolute humidity (AH) of inspired gas with a hygrometer. AH differed among HMEs applied to tracheostomized patients with spontaneous breathing. For all the HMEs, as tidal volume increased, AH decreased. At 20 breaths/min, AH was higher than at 10 breaths/min. For all the HMEs, when oxygen was delivered, AH decreased to below 30 mg/L. With an oxygen mask and high-flow CPAP, at all settings, AH exceeded 30 mg/L. None of the HMEs provided adequate humidification when supplemental oxygen was added. In the ICU, caution is required when applying HME to tracheostomized patients with spontaneous breathing, especially when supplemental oxygen is required.

Role of Aquaporin Water Channels in Airway Fluid Transport, Humidification, and Surface Liquid Hydration

Science.gov (United States)

Song, Yuanlin; Jayaraman, Sujatha; Yang, Baoxue; Matthay, Michael A.; Verkman, A.S.

2001-01-01

Several aquaporin-type water channels are expressed in mammalian airways and lung: AQP1 in microvascular endothelia, AQP3 in upper airway epithelia, AQP4 in upper and lower airway epithelia, and AQP5 in alveolar epithelia. Novel quantitative methods were developed to compare airway fluid transport–related functions in wild-type mice and knockout mice deficient in these aquaporins. Lower airway humidification, measured from the moisture content of expired air during mechanical ventilation with dry air through a tracheotomy, was 54–56% efficient in wild-type mice, and reduced by only 3–4% in AQP1/AQP5 or AQP3/AQP4 double knockout mice. Upper airway humidification, measured from the moisture gained by dry air passed through the upper airways in mice breathing through a tracheotomy, decreased from 91 to 50% with increasing ventilation from 20 to 220 ml/min, and reduced by 3–5% in AQP3/AQP4 knockout mice. The depth and salt concentration of the airway surface liquid in trachea was measured in vivo using fluorescent probes and confocal and ratio imaging microscopy. Airway surface liquid depth was 45 ± 5 μm and [Na+] was 115 ± 4 mM in wild-type mice, and not significantly different in AQP3/AQP4 knockout mice. Osmotic water permeability in upper airways, measured by an in vivo instillation/sample method, was reduced by ∼40% by AQP3/AQP4 deletion. In doing these measurements, we discovered a novel amiloride-sensitive isosmolar fluid absorption process in upper airways (13% in 5 min) that was not affected by aquaporin deletion. These results establish the fluid transporting properties of mouse airways, and indicate that aquaporins play at most a minor role in airway humidification, ASL hydration, and isosmolar fluid absorption. PMID:11382807

Installations for water desalination by reverse osmosis. P. 2

International Nuclear Information System (INIS)

Bauermann, H.D.; Ermert, U.

1974-01-01

Starting with the explanation of an installation scheme of a reverse osmosis (RO) plant for water desalination, the various parts of such a plant are firstly discussed briefly. After a chapter dealing with the feed pre-treatment required, the operation of RO-plants is dealt with. The usual variations of arrangement are shown, as well as some information given on maintenance and costs of such methods of desalination. The last part contains some examples of plants installed so far. (orig.) [de

Energy system impacts of desalination in Jordan

Directory of Open Access Journals (Sweden)

Poul Alberg Østergaard

2014-02-01

Full Text Available Climate change mitigation calls for energy systems minimising end-use demands, optimising the fuel efficiency of conversion systems, increasing the use of renewable energy sources and exploiting synergies wherever possible. In parallel, global fresh water resources are strained due to amongst others population and wealth increase and competitive water uses from agriculture and industry is causing many nations to turn to desalination technologies. This article investigates a Jordanian energy scenario with two different desalination technologies; reverse osmosis (RO driven by electricity and Multi Stage Flash (MSF desalination driven by Cogeneration of Heat and Power (CHP. The two systems impact the energy systems in different ways due to the technologies’ particular characteristics. The systems are analyses in the energy systems analysis model EnergyPLAN to determine the impacts on energy system performance. Results indicate that RO and MSF are similar in fuel use. While there is no use of waste heat from condensing mode plants, efficiencies for CHP and MSF are not sufficiently good to results in lower fuel usage than RO. The Jordanian energy system is somewhat inflexible giving cause to Critical Excess Electricity Production (CEEP even at relatively modest wind power penetrations. Here RO assists the energy system in decreasing CEEP – and even more if water storage is applied.

Forward-Osmosis Desalination with Poly(Ionic Liquid) Hydrogels as Smart Draw Agents.

Science.gov (United States)

Fan, Xuelin; Liu, Huili; Gao, Yating; Zou, Zhu; Craig, Vincent S J; Zhang, Guangzhao; Liu, Guangming

2016-06-01

The combination of high desalination efficiency, negligible draw-solute leakage, nontoxicity, ease of regeneration, and effective separation to produce liquid water makes the smart draw agents developed here highly suited for forward-osmosis desalination. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

EXPERIMENTAL RESEARCH OF THE INFLUENCE OF VARIOUS TYPES OF SOLAR COLLECTORS FOR PERFORMANCE SOLAR DESALINATION PLANT

Directory of Open Access Journals (Sweden)

Rakhmatulin I.R.

2014-04-01

Full Text Available The article discusses the possibility of using renewable energy for water purification. Results of analysis of a preferred energy source for a water purification using installed in places where fresh water shortages and a lack of electrical energy. The possibility of desalination of salt water using solar energy for regions with temperate climate. Presented desalination plant working on energy vacuum solar collectors, principles of action developed by the desalination plant. The experimental results of a constructed distiller when working with vacuum glass tubes and vacuum tubes with copper core inside. Conclusions about the possibility of using solar collectors for water desalination, are tips and tricks to improve the performance of solar desalination plant.

Electrokinetic desalination of protruded areas of stone avoiding the direct contact with electrodes

DEFF Research Database (Denmark)

Feijoo, J.; Matyscák, O.; Ottosen, Lisbeth M.

2017-01-01

of the sandstone highly contaminated with salts. Therefore, these results confirmed that it was possible to desalinate the sandstone using electrokinetic methods without the need to put in contact the affected areas with the equipment, reducing the possibility of altering it by manipulation.......Soluble salts are considered one of the main deterioration factors of porous building materials such as rocks, bricks or granites. The desalination treatments currently used in order to mitigate this alteration process are usually applied directly on the affected areas, which have often a low...... degree of cohesion precisely due to the deteriorating effect of the salts. The present study aimed to investigate the evaluation of a new approach based on electrokinetic techniques to desalinate rocks in monuments, specifically to desalinate carved reliefs. The procedure avoids the direct contact...

Pushing desalination recovery to the maximum limit: Membrane and thermal processes integration

KAUST Repository

Shahzad, Muhammad Wakil

2017-05-05

The economics of seawater desalination processes has been continuously improving as a result of desalination market expansion. Presently, reverse osmosis (RO) processes are leading in global desalination with 53% share followed by thermally driven technologies 33%, but in Gulf Cooperation Council (GCC) countries their shares are 42% and 56% respectively due to severe feed water quality. In RO processes, intake, pretreatment and brine disposal cost 25% of total desalination cost at 30–35% recovery. We proposed a tri-hybrid system to enhance overall recovery up to 81%. The conditioned brine leaving from RO processes supplied to proposed multi-evaporator adsorption cycle driven by low temperature industrial waste heat sources or solar energy. RO membrane simulation has been performed using WinFlow and IMSDesign commercial softwares developed by GE and Nitto. Detailed mathematical model of overall system is developed and simulation has been conducted in FORTRAN. The final brine reject concentration from tri-hybrid cycle can vary from 166,000ppm to 222,000ppm if RO retentate concentration varies from 45,000ppm to 60,000ppm. We also conducted economic analysis and showed that the proposed tri-hybrid cycle can achieve highest recovery, 81%, and lowest energy consumption, 1.76kWhelec/m3, for desalination reported in the literature up till now.

Impact of the water symmetry factor on humidification and cooling strategies for PEM fuel cell stacks

Energy Technology Data Exchange (ETDEWEB)

Picot, D; Metkemeijer, R; Bezian, J J; Rouveyre, L [Centre d` Energetique, Ecole des Mines de Paris, 06 - Sophia Antipolis (France)

1998-10-01

In this paper, experimental water and thermal balances with three proton exchange membrane fuel cells (PEMFC) are proposed. On the test facility of Ecole des Mines de Paris, three De Nora SPA fuel cell stacks have been successfully studied: An 1 kW{sub e} prototype using Nafion {sup trademark} 117, a 5 and 10 kW{sub e} module using Nafion {sup trademark} 115. The averaged water symmetry factor determines strategies to avoid drying membrane. So, we propose analytical solutions to find compromises between humidification and cooling conditions, which determines outlet temperatures of gases. For transport applications, the space occupied by the power module must be reduced. One of the main efforts consists in decreasing the operative pressure. Thus, if adequate cooling power is applied, we show experimentally and theoretically the possibility to use De Nora PEM fuel cells with low pressure, without specific external humidification. (orig.)

Effects of blending of desalinated water with treated surface drinking water on copper and lead release.

Science.gov (United States)

Liu, Haizhou; Schonberger, Kenneth D; Korshin, Gregory V; Ferguson, John F; Meyerhofer, Paul; Desormeaux, Erik; Luckenbach, Heidi

2010-07-01

This study examined effects of desalinated water on the corrosion of and metal release from copper and lead-containing materials. A jar test protocol was employed to examine metal release from copper and lead-tin coupons exposed to water chemistries with varying blending ratios of desalinated water, alkalinities, pHs and orthophosphate levels. Increasing fractions of desalinated water in the blends resulted in non-monotonic changes of copper and lead release, with generally lower metal concentrations in the presence of desalinated water, especially when its contribution increased from 80% to 100%. SEM examination showed that the increased fractions of desalinated water were associated with pronounced changes of the morphology of the corrosion scales, likely due to the influence of natural organic matter. This hypothesis was corroborated by the existence of correlations between changes of the zeta-potential of representative minerals (malachite and hydrocerussite) and metal release. For practical applications, maintaining pH at 7.8 and adding 1 mg/L orthophosphate as PO(4) were concluded to be adequate to decrease copper and lead release. Lower alkalinity of desalinated water was beneficial for blends containing 50% or more desalinated water. Copyright 2010 Elsevier Ltd. All rights reserved.

Influence of mouth opening on oropharyngeal humidification and temperature in a bench model of neonatal continuous positive airway pressure.

Science.gov (United States)

Fischer, Hendrik S; Ullrich, Tim L; Bührer, Christoph; Czernik, Christoph; Schmalisch, Gerd

2017-02-01

Clinical studies show that non-invasive respiratory support by continuous positive airway pressure (CPAP) affects gas conditioning in the upper airways, especially in the presence of mouth leaks. Using a new bench model of neonatal CPAP, we investigated the influence of mouth opening on oropharyngeal temperature and humidity. The model features the insertion of a heated humidifier between an active model lung and an oropharyngeal head model to simulate the recurrent expiration of heated, humidified air. During unsupported breathing, physiological temperature and humidity were attained inside the model oropharynx, and mouth opening had no significant effect on oropharyngeal temperature and humidity. During binasal CPAP, the impact of mouth opening was investigated using three different scenarios: no conditioning in the CPAP circuit, heating only, and heated humidification. Mouth opening had a strong negative impact on oropharyngeal humidification in all tested scenarios, but heated humidification in the CPAP circuit maintained clinically acceptable humidity levels regardless of closed or open mouths. The model can be used to test new equipment for use with CPAP, and to investigate the effects of other methods of non-invasive respiratory support on gas conditioning in the presence of leaks. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Design aspects of a multipurpose fusion power plant for desalination and agrochemical processes

International Nuclear Information System (INIS)

Sabri, Z.A.

1975-02-01

A description is given of the skeletal structure of a multipurpose fusion power plant, designed for desalination and agrochemicals production. The plant is a complex that comprises dual purpose power and desalination units, separation and processing units for recovery of soluble salts in the effluent of the desalination unit, mariculture units for production of algae for food and as food for shrimp and other fish species. The electrical power unit is a two-component fusion device that burns deuterium and helium-3 utilizing a fast fusion cycle

Determination of the costs of the nuclear desalination using the DEEP code from IAEA

International Nuclear Information System (INIS)

Ramirez S, J.R.; Palacios H, J.C.; Alonso V, G.

2005-01-01

The desalination of seawater is being an important solution to satisfy the demands of drinking water to population's centers that have hydric resources very limited, like it is the case of some Arab countries and arid regions of the planet, in where they have settled desalination plants that use as energy source to those fossil fuels or nuclear energy plants. Taking into account that the desalination of seawater is a process that consumes a lot of thermal and/or electric energy, it is necessary to quantify the costs of the supply and that of the desalination plant for different options and technologies, looking for this way the but appropriate for the specific conditions of the region where it has planned the desalination of seawater. In this report the three technologies but promising for the desalination are described and by means of the DEEP code the costs of production of water and energy are evaluated, using as thermal source different types of power nuclear reactors. It was obtained according to DEEP that the costs of the electricity generation for the considered reactors are around 40 USD/MWh. With these costs of electric power generation and using the DEEP code is obtained that the costs of production of drinking water are around 1 USD/m 3 . (Author)

Sustainable renewable energy seawater desalination using combined-cycle solar and geothermal heat sources

KAUST Repository

Missimer, Thomas M.; Kim, Youngdeuk; Rachman, Rinaldi; Ng, Kim Choon

2013-01-01

Key goals in the improvement of desalination technology are to reduce overall energy consumption, make the process "greener," and reduce the cost of the delivered water. Adsorption desalination (AD) is a promising new technology that has great

Techno-economic evaluation of a solar powered water desalination plant

International Nuclear Information System (INIS)

Fiorenza, G.; Sharma, V.K.; Braccio, G.

2003-01-01

Water desalination technologies and their possible coupling with solar energy have been evaluated. The topic is of particular interest, especially for countries located within the Southern Mediterranean belt, generally characterized with vast arid and isolated areas having practically no access to electric power from the national grid. Economic factors being one of the main barriers to diffusion of solar devices so far, an attempt has been made to estimate the water production cost for two different seawater desalination systems: reverse osmosis and multiple effect, powered by a solar thermal and a photovoltaic field, respectively. The results obtained for plants of capacity varying between 500 and 5000 m 3 /d have been compared to results concerning a conventional desalination system. In addition, the influences of various parameters, such as depreciation factor, economic incentives, PV modules cost and oil price, have also been considered

Applications of heat pipes for HVAC dehumidification at Walt Disney World

International Nuclear Information System (INIS)

Allen, P.J.; Dinh, K.

1993-01-01

This paper presents the theory and application of heat pipes for HVAC dehumidification purposes. In HVAC applications, a heat pipe is used as a heat exchanger that transfers heat from the return air directly to the supply air. The air is pre-cooled entering the cooling coil and reheated using the same heat removed from the return air. While consuming no energy, the heat pipe lets the evaporator coil operate at a lower temperature, increasing the moisture removal capabilities of the HVAC system by 50% to 100%. WALT DISNEY WORLD is currently testing several heat pipe applications ranging from 1 to 240 tons. The applications include (1) water attractions (2) museums/artifacts areas (3) resort guest rooms and (4) locker rooms. Actual energy usage and relative humidity reductions are shown to determine the effectiveness of the heat pipe as an energy efficient method of humidity control

Optimal design and control of solar driven air gap membrane distillation desalination systems

International Nuclear Information System (INIS)

Chen, Yih-Hang; Li, Yu-Wei; Chang, Hsuan

2012-01-01

Highlights: ► Air gap membrane distillation unit was used in the desalination plants. ► Aspen Custom Molder was used to simulate each unit of desalination plants. ► Design parameters were investigated to obtain the minimum total annual cost. ► The control structure was proposed to operate desalination plants all day long. -- Abstract: A solar heated membrane distillation desalination system is constructed of solar collectors and membrane distillation devices for increasing pure water productivity. This technically and economically feasible system is designed to use indirect solar heat to drive membrane distillation processes to overcome the unstable supply of solar radiation from sunrise to sunset. The solar heated membrane distillation desalination system in the present study consisted of hot water storage devices, heat exchangers, air gap membrane distillation units, and solar collectors. Aspen Custom Molder (ACM) software was used to model and simulate each unit and establish the cost function of a desalination plant. From Design degree of freedom (DOF) analysis, ten design parameters were investigated to obtain the minimum total annual cost (TAC) with fixed pure water production rate. For a given solar energy density profile of typical summer weather, the minimal TAC per 1 m 3 pure water production can be found at 500 W/m 2 by varying the solar energy intensity. Therefore, we proposed two modes for controlling the optimal design condition of the desalination plant; day and night. In order to widen the operability range of the plant, the sensitivity analysis was used to retrofit the original design point to lower the effluent temperature from the solar collector by increasing the hot water recycled stream. The simulation results show that the pure water production can be maintained at a very stable level whether in sunny or cloudy weather.

Safety aspects of nuclear plants coupled with seawater desalination units

International Nuclear Information System (INIS)

2001-08-01

The purpose of this publication is to address the safety and licensing aspects of nuclear power plants for which a significant portion of the heat energy produced by the reactor is intended for use in heat utilization applications. Although intended to cover the broad spectrum of nuclear heat applications, the focus of the discussion will be the desalination of sea water using nuclear power plants as the energy source for the desalination process

Reverse osmosis desalination of chitosan cross-linked graphene oxide/titania hybrid lamellar membranes.

Science.gov (United States)

Deng, Hui; Sun, Penzhan; Zhang, Yingjiu; Zhu, Hongwei

2016-07-08

With excellent mass transport properties, graphene oxide (GO)-based lamellar membranes are believed to have great potential in water desalination. In order to quantify whether GO-based membranes are indeed suitable for reverse osmosis (RO) desalination, three sub-micrometer thick GO-based lamellar membranes: GO-only, reduced GO (RGO)/titania (TO) nanosheets and RGO/TO/chitosan (CTS) are prepared, and their RO desalination performances are evaluated in a home-made RO test apparatus. The photoreduction of GO by TO improves the salt rejection, which increases slowly with the membrane thickness. The RGO/TO/CTS hybrid membranes exhibit higher rejection rates of only about 30% (greater than threefold improvement compared with a GO-only membrane) which is still inferior compared to other commercial RO membranes. The low rejection rates mainly arise from the pressure-induced weakening of the ion-GO interlayer interactions. Despite the advantages of simple, low-cost preparation, high permeability and selectivity of GO-based lamellar membranes, as the current desalination performances are not high enough to afford practical application, there still remains a great challenge to realize high performance separation membranes for water desalination applications.

A Well Water Reverse Osmosis Desalination Unit Diagnosis

International Nuclear Information System (INIS)

Elfil, H.; Hila, M.; Hannachi, A.; Yeza, A.

2009-01-01

In this present work the diagnosis results of a reverse osmosis desalination unit are reported. Since 1997, the desalination unit was supplying a 1200 bed hotel. The feed water was driven from a well situated 300 m away form the sea. The water has an approximate salinity of 6gg.L -1 . The unit was producing 600 m 3 per day of desalinated water with a Total Dissolved Salts (TDS) of nearly 400 mg.L -1 . The desalination unit has two stages with 67 pour cent and 42 pour cent yields respectively giving an average yield of 81 pour cent. The behavior of all water streams with respect to aggressiveness and scaling tendency was assessed. The 2nd stage reject water was shown to exhibit a very high scaling behavior with an instantaneous precipitation in the absence of feed water chemical treatment. The analyses have shown that the produced water was very aggressive. The second stage module autopsy has revealed a sharp decrease of the membrane performances because of mineral as well as organic fooling buildup. The inorganic scale was essentially made of coesite and calcite and kaolinite clay. The presence of silica and clay could be attributed to an inadequate filtration pre-treatment process that was not able to retain all the suspended matter in the feed water. Whereas the presence calcite crystals at the membrane surface, reveals that the chemical inhibition performed at the pre-treatment process without adjusting the water pH was not able to prevent calcium carbonate precipitation. A periodic acid wash of the 2nd stage membranes is then necessary to guarantee this stage desired objectives.

IAEA activity related to safety of nuclear desalination

International Nuclear Information System (INIS)

Gasparini, M.

2000-01-01

The nuclear plants for desalination to be built in the future will have to meet the standards of safety required for the best nuclear power plants currently in operation or being designed. The current safety approach, based on the achievement of the fundamental safety functions and defence in depth strategy, has been shown to be a sound foundation for the safety and protection of public health, and gives the plant the capability of dealing with a large variety of sequences, even beyond the design basis. The Department of Nuclear Safety of the IAEA is involved in many activities, the most important of which are to establish safety standards, and to provide various safety services and technical knowledge in many Technical Co-operation assistance projects. The department is also involved in other safety areas, notably in the field of future reactors. The IAEA is carrying out a project on the safety of new generation reactors, including those used for desalination, with the objective of fostering an exchange of information on safety approaches, promoting harmonization among Member States and contributing towards the development and revision of safety standards and guidelines for nuclear power plant design. The safety, regulatory and environmental concerns in nuclear powered desalination are those related directly to nuclear power plants, with due consideration given to the coupling process. The protection of product water against radioactive contamination must be ensured. An effective infrastructure, including appropriate training, a legal framework and regulatory regime, is a prerequisite to considering use of nuclear power for desalination plants, also in those countries with limited industrial infrastructures and little experience in nuclear technology or safety. (author)

Comparison of Configurations for High-Recovery Inland Desalination Systems

Directory of Open Access Journals (Sweden)

Philip A. Davies

2012-09-01

Full Text Available Desalination of brackish groundwater (BW is an effective approach to augment water supply, especially for inland regions that are far from seawater resources. Brackish water reverse osmosis (BWRO desalination is still subject to intensive energy consumption compared to the theoretical minimum energy demand. Here, we review some of the BWRO plants with various system arrangements. We look at how to minimize energy demands, as these contribute considerably to the cost of desalinated water. Different configurations of BWRO system have been compared from the view point of normalized specific energy consumption (SEC. Analysis is made at theoretical limits. The SEC reduction of BWRO can be achieved by (i increasing number of stages, (ii using an energy recovery device (ERD, or (iii operating the BWRO in batch mode or closed circuit mode. Application of more stages not only reduces SEC but also improves water recovery. However, this improvement is less pronounced when the number of stages exceeds four. Alternatively and more favourably, the BWRO system can be operated in Closed Circuit Desalination (CCD mode and gives a comparative SEC to that of the 3-stage system with a recovery ratio of 80%. A further reduction of about 30% in SEC can be achieved through batch-RO operation. Moreover, the costly ERDs and booster pumps are avoided with both CCD and batch-RO, thus furthering the effectiveness of lowering the costs of these innovative approaches.

Selection of Nuclear Desalination Technology in East Kalimantan Province

International Nuclear Information System (INIS)

Siti Alimah; Sudi Ariyanto; Erlan Dewita; Budiarto; Geni R Sunaryo

2009-01-01

Nowadays, electricity demand in East Kalimantan increases with a rate of 12% per annum. Since the electricity supply produced by PT PLN increases 8,5% per annum, then it can consequently an occurrence of electricity shortage in the region. NPP may be regarded as one viable option to overcome the problem. In case of fresh water availability, the supply is also less than the demand. Therefore, a serious effort is necessary. Nuclear desalination, which is a process of separating dissolved salts of seawater or brackish water, can be coupled to the NPP to produce fresh water. There are some desalination technology commonly used in the world i.e. MSF (Multi-Stage Flash Distillation), MED (Multi-Effect Distillation) and RO (Reverse Osmosis). This paper shows the study result of selection for desalination technology to obtain the optimum solution. The selection is done based on the thirteen important parameters, which are estimated to affect on determine technology option on the nuclear desalination with a weighing factor with ranges from 1 to 4. The most favourable technology is that with the highest point. The result show that MED has highest weighing factor that is 39, followed 36 for RO and 33 for MSF. Since the water quality requirement to supply NPP is about 1 ppm and to supply public demand is below 1000 ppm, so a hybrid system of MED-RO is optimum option to produce fresh water. (author)

Status and prospect of R and D aimed at application of nuclear reactors for seawater desalination in Russia

International Nuclear Information System (INIS)

Zverev, K.V.; Baranaev, Y.D.; Toshinsky, G.I.; Polunichev, V.I.; Romenkov, A.A.; Shamanin, V.G.; Podberezny, V.L.

2004-01-01

In the document 'Strategy of Nuclear Power Development in Russia for the First Half of XXI Century', approved by the Government of the RF, seawater desalination is considered as a prospective area of application of the small-sized nuclear power plants (SNPP). Taking into account vast water resources of Russia evenly distributed over the territory of the country, seawater desalination is not a vital domestic demand for this country. Therefore, the R and D activities of the RF MINATOM institutions on nuclear desalination are aimed mainly at the assessment of implementation of the SNPP based nuclear desalination system in the developing countries suffering from the lack of fresh water supply. Within these activities, analysis of engineering and economical problems related to optimisation of the use of different type nuclear reactors as a source of electricity and heat for seawater desalination plants has been performed. The objective of the work is to develop scientific and technological basis for comprehensive design studies required for practical implementation of the projects. An important factor stimulating the R and D on nuclear desalination is rather active involvement of the MINATOM's institutions in the various activities in this field organised and coordinated by the IAEA. Since 1998, SRC RF-IPPE, OKBM, ENTEK, MALAYA ENERGETIKA, JSC, and VNIPI PROMTECHNOLOGIYI etc. have been participants of the IAEA Coordinated Research Program (CRP) on 'Optimization of Coupling of Nuclear Reactor and Desalination System'. This work is being carried out within the framework of special Russian Project: 'Use of Small Size Russian Nuclear Reactors as Power Source for Nuclear Desalination Complexes: Optimization of Coupling Schemes, Design and Economical Characteristics'. The small nuclear reactors KLT-40C, NIKA and RUTA are considered in the study. In 2002, IAEA initiates new CRP 'Economic Research on, and Assessment of, selected Nuclear Desalination Projects and Case Studies

Carbon electrode for desalination purpose in capacitive deionization

International Nuclear Information System (INIS)

Endarko,; Fadilah, Nurul; Anggoro, Diky

2016-01-01

Carbon electrodes for desalination purpose have been successfully synthesized using activated carbon powder (BET surface area=700 – 1400 m 2 /g), carbon black and polyvinyl alcohol (PVA) binder by cross-linking method with glutaric acid (GA) at 120 °C. The electrochemical properties of the carbon electrodes were analyzed using electrical impedance spectroscopy (EIS) and cyclic voltammetry (CV) whilst the physical properties were observed with scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDX). In order to assess the desalting performance, salt removal experiments were performed by constructing a capacitive deionization unit cell with five pairs of carbon electrodes. For each pair consisted of two parallel carbon electrodes separated by a spacer. Desalination and regeneration processes were also observed in the salt-removal experiments. The salt-removal experiments were carried out in single-pass mode using a solution with 0.1 M NaCl at a flow rate of 10 mL/min. A voltage of 3 V was applied to the cell for 60 minutes for both processes in desalination and regeneration. The result showed that the percentage value of the salt-removal was achieved at 20%.

Preparation and desalination performance of multiwall carbon nanotubes

International Nuclear Information System (INIS)

Zhang Dengsong; Shi Liyi; Fang Jianhui; Dai Kai; Li Xuanke

2006-01-01

Multiwall carbon nanotubes (MWCNTs) were prepared by catalytic decomposition of methane at 680-700 deg. C, using nickel oxide-silica binary aerogels as the catalyst. The morphological structure of MWCNTs was investigated by transmission electron microscopy (TEM), X-ray diffraction (XRD) and Raman spectroscopy. The results revealed that MWCNTs had a diameter of 40-60 nm, with high quality and high length/diameter ratio, and some metal catalyst particles were encapsulated at the tip of nanotubes. Using MWCNTs as the electrodes of flow-through capacitor (FTC), desalination performance was investigated. The results showed that modification methods had great effect on desalination performance of MWCNTs. The removal amount of NaCl was generally dependent on the surface area and pore volume of MWCNTs. After modification in diluted HNO 3 solution with ultrasonic and then ball milling, the metal catalyst particles at the tip of nanotubes disappeared, the nanotube length became short, the cap at the tip of nanotubes was opened, the internal surface area could be effectively used, leading to increasing the specific surface area and pore volume for MWCNTs, and thus, the desalination performance thereof was the best of all

Tracing disinfection byproducts in full-scale desalination plants

KAUST Repository

Le Roux, Julien

2015-03-01

The aim of this study was to assess the formation and the behavior of halogenated byproducts (regulated THMs and HAAs, as well as nitrogenous, brominated and iodinated DBPs including the emerging iodo-THMs) along the treatment train of full-scale desalination plants. One thermal multi-stage flash distillation (MSF) plant and two reverse osmosis (RO) plants located on the Red Sea coast of Saudi Arabia. DBPs formed during the prechlorination step were efficiently removed along the treatment processes (MSF or RO). Desalination plants fed with good seawater quality and using intermittent chlorine injection did not show high DBP formation and discharge. One RO plant with a lower raw water quality and using continuous chlorination at the intake formed more DBPs. In this plant, some non-regulated DBPs (e.g., dibromoacetonitrile and iodo-THMs) reached the product water in low concentrations (< 1.5 μg/L). Regulated THMs and HAAs were far below their maximum contamination levels set by the US Environmental Protection Agency. Substantial amounts of DBPs are disposed to the sea; low concentrations of DBPs were indeed detected in the water on shore of the desalination plants.

Carbon electrode for desalination purpose in capacitive deionization

Energy Technology Data Exchange (ETDEWEB)

Endarko,, E-mail: endarko@physics.its.ac.id; Fadilah, Nurul; Anggoro, Diky [Physics Department, Institut Teknologi Sepuluh Nopember (ITS) Kampus ITS, Sukolilo Surabaya 60111, Jawa Timur (Indonesia)

2016-03-11

Carbon electrodes for desalination purpose have been successfully synthesized using activated carbon powder (BET surface area=700 – 1400 m{sup 2}/g), carbon black and polyvinyl alcohol (PVA) binder by cross-linking method with glutaric acid (GA) at 120 °C. The electrochemical properties of the carbon electrodes were analyzed using electrical impedance spectroscopy (EIS) and cyclic voltammetry (CV) whilst the physical properties were observed with scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDX). In order to assess the desalting performance, salt removal experiments were performed by constructing a capacitive deionization unit cell with five pairs of carbon electrodes. For each pair consisted of two parallel carbon electrodes separated by a spacer. Desalination and regeneration processes were also observed in the salt-removal experiments. The salt-removal experiments were carried out in single-pass mode using a solution with 0.1 M NaCl at a flow rate of 10 mL/min. A voltage of 3 V was applied to the cell for 60 minutes for both processes in desalination and regeneration. The result showed that the percentage value of the salt-removal was achieved at 20%.

Nuclear floating power desalination complexes

International Nuclear Information System (INIS)

Panov, Y.K.; Polunichev, V.I.; Zverev, K.V.

1998-01-01

Russia is a single country in the world which possesses a powerful ice-breaker transport fleet that allows a solution of important social-economic tasks of the country's northern regions by maintaining a year-round navigation along the Arctic sea route. A total operating record of the marine nuclear reactors up until till now exceeds 150 reactor-years, with their main equipment operating life reacting 120 thousand hours. Design and constructional progresses have been made continuously during forty years of nuclear-powered ships construction in Russia. Well proven technology of all components experienced in the marine nuclear reactors give grounds to recommend marine NSSSs of KLT-40 type as energy sources for the heat and power co-generation plants and the sea water desalination complexes, particularly as a floating installation. Co-generation stations are considered for deployment in the extreme Northern Region of Russia. Nuclear floating desalination complexes can be used for drinkable water production in the coastal regions of Northern Africa, the Near East, India etc. (author)

Small and medium size nuclear power reactors for desalination

International Nuclear Information System (INIS)

Raisic, N.; Goodman, E.I.

1976-01-01

Taking the water needs, e.g. of some of the world's major towns, as a basis, it is investigated whether nuclear energy can be utilized economically for desalination. When a certain distance for the transport of water from other regions is exceeded it is quite possible that nuclear desalination becomes economical. Taking the example of Honkong, it is shown that this method can find application for other reasons, too, e.g. if the need exceeds the possibilities there are of meeting this need from natural sources. (UA) [de

Control and Modelling of Seawater Desalination Using Solar Technology

Energy Technology Data Exchange (ETDEWEB)

Roca, L.; Yebra, L. J.; Berenguel, M.; Alarcon, D. C.

2006-07-01

Desalination plants play a fundamental role in fighting the shortage of fresh water in places with plentiful seawater resources. This paper briefly describes a solar desalination system designed, erected and operated in the AQUASOL project at the Plataforma Solar de Almeria (PSA), consisting basically of a CPC (Compound Parabolic Concentrator) solar collector field, two water storage tanks, a multi-effect distillation plant (MED) and a Double Effect Absorption Heat Pump (DEAHP). These subsystems have been modeled to estimate system behaviour and develop control techniques for maintaining optimal operating conditions. (Author)

A comparative evaluation of different types of microbial electrolysis desalination cells for malic acid production.

Science.gov (United States)

Liu, Guangli; Zhou, Ying; Luo, Haiping; Cheng, Xing; Zhang, Renduo; Teng, Wenkai

2015-12-01

The aim of this study was to investigate different microbial electrolysis desalination cells for malic acid production. The systems included microbial electrolysis desalination and chemical-production cell (MEDCC), microbial electrolysis desalination cell (MEDC) with bipolar membrane and anion exchange membrane (BP-A MEDC), MEDC with bipolar membrane and cation exchange membrane (BP-C MEDC), and modified microbial desalination cell (M-MDC). The microbial electrolysis desalination cells performed differently in terms of malic acid production and energy consumption. The MEDCC performed best with the highest malic acid production rate (18.4 ± 0.6 mmol/Lh) and the lowest energy consumption (0.35 ± 0.14 kWh/kg). The best performance of MEDCC was attributable to the neutral pH condition in the anode chamber, the lowest internal resistance, and the highest Geobacter percentage of the anode biofilm population among all the reactors. Copyright © 2015 Elsevier Ltd. All rights reserved.

A preliminary economic feasibility assessment of nuclear desalination in Madura Island

International Nuclear Information System (INIS)

Kim, S.-H.; Hwang, Y.-D.; Konishi, T.; Hudi Hastowo

2005-01-01

A joint study between KAERI and BATAN, which is entitled 'A preliminary economic feasibility assessment of nuclear desalination in Madura Island', is being conducted under the framework of the Interregional Technical Cooperation Project of IAEA, signed on Oct. 10, 2001 at IAEA. The duration of the project is January 2002 to December 2004. An economic feasibility of nuclear desalination using system-integrated modular advanced reactor (SMART), which will provide Madura Island with electricity and potable water and also support industrialisation and tourism, will be assessed during the project. The scope of this joint study includes the analyses for the short- and long-term energy and water demand as well as the supply plan for Madura Island, evaluation of the site characteristics, environmental impacts and health aspects, technical and economic evaluation of SMART and its desalination system, including the feasibility of its being identified on the Madura Island. KAERI and BATAN are cooperating in conducting a joint study, and IAEA provides technical support and a review of the study products. This paper presents the interim results of the joint study by focussing on the technical and economic aspects of nuclear desalination using SMART in Madura Island. (author)

Direct seawater desalination by ion concentration polarization

Science.gov (United States)

Kim, Sung Jae; Ko, Sung Hee; Kang, Kwan Hyoung; Han, Jongyoon

2010-04-01

A shortage of fresh water is one of the acute challenges facing the world today. An energy-efficient approach to converting sea water into fresh water could be of substantial benefit, but current desalination methods require high power consumption and operating costs or large-scale infrastructures, which make them difficult to implement in resource-limited settings or in disaster scenarios. Here, we report a process for converting sea water (salinity ~500 mM or ~30,000 mg l-1) to fresh water (salinity water is divided into desalted and concentrated streams by ion concentration polarization, a phenomenon that occurs when an ion current is passed through ion-selective membranes. During operation, both salts and larger particles (cells, viruses and microorganisms) are pushed away from the membrane (a nanochannel or nanoporous membrane), which significantly reduces the possibility of membrane fouling and salt accumulation, thus avoiding two problems that plague other membrane filtration methods. To implement this approach, a simple microfluidic device was fabricated and shown to be capable of continuous desalination of sea water (~99% salt rejection at 50% recovery rate) at a power consumption of less than 3.5 Wh l-1, which is comparable to current state-of-the-art systems. Rather than competing with larger desalination plants, the method could be used to make small- or medium-scale systems, with the possibility of battery-powered operation.

Low temperature desalination using solar collectors augmented by thermal energy storage

International Nuclear Information System (INIS)

Gude, Veera Gnaneswar; Nirmalakhandan, Nagamany; Deng, Shuguang; Maganti, Anand

2012-01-01

Highlights: ► A new low temperature desalination process using solar collectors was investigated. ► A thermal energy storage tank (TES) was included for continuous process operation. ► Solar collector area and TES volumes were optimized by theoretical simulations. ► Economic analysis for the entire process was compared with and without TES tank. ► Energy and emission payback periods for the solar collector system were reported. -- Abstract: A low temperature desalination process capable of producing 100 L/d freshwater was designed to utilize solar energy harvested from flat plate solar collectors. Since solar insolation is intermittent, a thermal energy storage system was incorporated to run the desalination process round the clock. The requirements for solar collector area as well as thermal energy storage volume were estimated based on the variations in solar insolation. Results from this theoretical study confirm that thermal energy storage is a useful component of the system for conserving thermal energy to meet the energy demand when direct solar energy resource is not available. Thermodynamic advantages of the low temperature desalination using thermal energy storage, as well as energy and environmental emissions payback period of the system powered by flat plate solar collectors are presented. It has been determined that a solar collector area of 18 m 2 with a thermal energy storage volume of 3 m 3 is adequate to produce 100 L/d of freshwater round the clock considering fluctuations in the weather conditions. An economic analysis on the desalination system with thermal energy storage is also presented.

Low grade heat utilisation for seawater desalination by the HTTF process

Energy Technology Data Exchange (ETDEWEB)

Chandrasekhar, M. [Desalination Division, Bhabha Atomic Research Centre (BARC), Trombay, Mumbai (India)]. E-mail: mchansh@magnum.barc.ernet.in; Majumdar, M.; Srivastava, V.K.; Tewari, P.K. [Desalination Division, Bhabha Atomic Research Centre (BARC), Trombay, Mumbai (India)

2006-07-01

To improve heat transfer efficiency, Horizontal Tube Thin Film (HTTF) evaporators are being used in multieffect desalination plants. These plants require less pumping energy than thermal-based desalination plants. To generate the design data, experimental studies were carried out in a single-tube HTTF experimental setup, and heat transfer correlations were developed at BARC. The experimental findings and results are presented and discussed in this paper. (author)

Adsorption Characteristics of Water and Silica Gel System for Desalination Cycle

KAUST Repository

Cevallos, Oscar R.

2012-07-01

An adsorbent suitable for adsorption desalination cycles is essentially characterized by a hydrophilic and porous structure with high surface area where water molecules are adsorbed via hydrogen bonding mechanism. Silica gel type A++ possesses the highest surface area and exhibits the highest equilibrium uptake from all the silica gels available in the market, therefore being suitable for water desalination cycles; where adsorbent’s adsorption characteristics and water vapor uptake capacity are key parameters in the compactness of the system; translated as feasibility of water desalination through adsorption technologies. The adsorption characteristics of water vapor onto silica gel type A++ over a temperature range of 30 oC to 60 oC are investigated in this research. This is done using water vapor adsorption analyzer utilizing a constant volume and variable pressure method, namely the Hydrosorb-1000 instrument by Quantachrome. The experimental uptake data is studied using numerous isotherm models, i. e. the Langmuir, Tóth, generalized Dubinin-Astakhov (D-A), Dubinin-Astakhov based on pore size distribution (PSD) and Dubinin-Serpinski (D-Se) isotherm for the whole pressure range, and for a pressure range below 10 kPa, proper for desalination cycles; isotherms type V of the International Union of Pure and Applied Chemistry (IUPAC) classification were exhibited. It is observed that the D-A based on PSD and the D-Se isotherm models describe the best fitting of the experimental uptake data for desalination cycles within a regression error of 2% and 6% respectively. All isotherm models, except the D-A based on PSD, have failed to describe the obtained experimental uptake data; an empirical isotherm model is proposed by observing the behavior of Tóth and D-A isotherm models. The new empirical model describes the water adsorption onto silica gel type A++ within a regression error of 3%. This will aid to describe the advantages of silica gel type A++ for the design of

Nuclear desalination for the northwest of Mexico; Desalacion nuclear para el noroeste de Mexico

Energy Technology Data Exchange (ETDEWEB)

Ortega C, R. F. [Instituto de Ingenieria, UNAM, 04510 Mexico D.F. (Mexico)

2008-07-01

The IMPULSA project of the Engineering Institute of UNAM, it has dedicated from the year 2005 to the study and development of new desalination technologies of seawater with renewable energies. The objective is to form a group of expert engineers and investigators in the desalination topics able to transform their scientific knowledge in engineering solutions, with a high grade of knowledge of the environment and the renewable energies. In the middle of 2007 was took the initiative in the IMPULSA project to study the nuclear desalination topic. It is evident that before the high cost of the hydrocarbons and its high environmental impact, the nuclear generation alternative of energy becomes extremely attractive, mainly for desalination projects of seawater of great size. The Northwest of Mexico is particularly attractive as the appropriate site for one nuclear desalination plant of great size given its shortage of drink water and the quick growth of its population; as well as its level of tourist, agricultural and industrial activity. In this study was revised the state of the art of the nuclear desalination on the world and it is simulated some couplings and operation forms of nuclear reactors and desalination units, from the thermodynamic and economic viewpoint with the purpose of identifying the main peculiarities of this technology. The objective of the study was to characterize several types and sizes of nuclear reactors of the last generation that could be couple to a desalination technology as multi-stage distillation, type flash distillation or inverse osmosis. It is used for this effect the DEEP 3.1 program of the IAEA to simulate the coupling and to carry out an economic preliminary evaluation. Was found cost very competitive of 0.038-0.044 US$/kWh for the electric power production and 0.60 to 0.77 US$/m{sup 3} for the drink water produced, without including the water transport cost or the use of carbon certificates. (Author)

Safety analysis of coupling system of hybrid (MED-RO) nuclear desalination system utilising waste heat from HTGR

International Nuclear Information System (INIS)

Raha, Abhijit; Kishore, G.; Rao, I.S.; Adak, A.K.; Srivastava, V.K.; Prabhakar, S.; Tewari, P.K.

2010-01-01

To meet the generation IV goals, High Temperature Gas Cooled Reactors (HTGRs) are designed to have relatively higher thermal efficiency and enhanced safety and environmental characteristics. It can provide energy for combined production of hydrogen, electricity and other industrial applications. The waste heat available in the HTGR power cycle can also be utilized for the desalination of seawater for producing potable water. Desalination is an energy intensive process, so use of waste heat from HTGR certainly makes desalination process more affordable to create fresh water resources. So design of the coupling system, as per the safety design requirement of nuclear desalination plant, of desalination plant with HTGR is very crucial. In the first part of this paper, design of the coupling system between hybrid Multi Effect Desalination-Reverse Osmosis (MED-RO) nuclear desalination plant and HTGR to utilize the waste heat in HTGR are discussed. In the next part deterministic safety analysis of the designed coupling system of are presented in detail. It was found that all the coupling system meets the acceptance criteria for all the Postulated Initiating Events (PIE's) limited to DBA. (author)

Heat loss during carbon dioxide insufflation: comparison of a nebulization based humidification device with a humidification and heating system.

Science.gov (United States)

Noll, Eric; Schaeffer, Roland; Joshi, Girish; Diemunsch, Sophie; Koessler, Stefanie; Diemunsch, Pierre

2012-12-01

This study compared the heat loss observed with the use of MR860 AEA Humidifier™ system (Fisher & Paykel Healthcare, New Zealand), which humidifies and heats the insufflated CO(2), and the use of the AeronebPro™ device (Aerogen, Ireland), which humidifies but does not heat the insufflated CO(2). With institutional approval, 16 experiments were conducted in 4 pigs. Each animal, acting as its own control, was studied at 8-day intervals in randomized sequence with the following four conditions: (1) control (C) no pneumoperitoneum; (2) standard (S) insufflation with nonhumidified, nonheated CO(2); (3) Aeroneb™ (A): insufflation with humidified, nonheated CO(2); and (4) MR860 AEA humidifier™ (MR): insufflation with humidified and heated CO(2). The measured heat loss after 720L CO(2) insufflation during the 4 h was 1.03 ± 0.75 °C (mean ± SEM) in group C; 3.63 ± 0.31 °C in group S; 3.03 ± 0.39 °C in group A; and 1.98 ± 0.09 °C in group MR. The ANOVA showed a significant difference with time (p = 0.0001) and with the insufflation technique (p = 0.024). Heat loss in group C was less than in group S after 60 min (p = 0.03), less than in group A after 70 min (p = 0.03), and less than in group MR after 150 min (p = 0.03). The heat loss in group MR was less than in group S after 50 min (p = 0.04) and less than in group A after 70 min (p = 0.02). After 160 min, the heat loss in group S was greater than in group A (p = 0.03). As far as heat loss is concerned, for laparoscopic procedures of less than 60 min, there is no benefit of using any humidification with or without heating. However, for procedures greater than 60 min, use of heating along with humidification, is superior.