Environmental impact of seawater desalination plants. Molten salt reactors and thermal desalination to transform. All thermal desalination processes are more efficient at higher temperatures, but above. Desalination is the removal of dissolved salts and other impurities from salt water.
European desalination society courses in desalination. Take the lowtemperature multieffect desalination equipment as an example. Low temperature thermal desalination lttd process uses the available temperature gradient between two water bodies or flows to evaporate the warmer water at low pressures and condense the resultant vapour with the colder water to obtain fresh water. This article is dedicated to the first ever floating 1 mld floating barge mounted, low temperature thermal desalination plant commissioned by. The system uses vacuum pumps to create a low pressure, low temperature environment in which water evaporates even at a temperature gradient of.
National institute of ocean technology niot has been working extensively on lttd process since. Approximately 620 kwh of evaporation enthalpy is necessary to obtain 1 t of drinking water. Performance analysis of evaporationfreezing desalination. A desalination plant turns salt water brackish or seawater into fresh water potable or.
Thermal desalination using mems and salinitygradient. American journal of engineering research ajer 20 w w w. Thermal thermal desalination exploits the fact that water molecules vaporise at a lower temperature than dissolved salts and other molecules. Vibration analysis of shell and tube heat exchanger for low temperature thermal desalination plant. According to some studies, thermal desalination consumes approximately 1. Therefore, feed water can be heated and then evaporated to separate out the dissolved salts from pure water. Temperature thermal desalination lttd muthunayagam et al. Thermal solar energy water desalination is known to be a viable method of. Titans low temperature thermal desalination plant operates utilizing flash evapor. Pdf performance limits and opportunities for low temperature. Next generation solar technology could drive down the cost of scrubbing salt from seawater.
Government printing office, washington, dc 204029325. Technical report on design and execution of desalination. Darwish,iain mcgregor 2005, thermal desalination processes,fundamentals and practice,five. Currently, ro is the most widely used method for desalination in the united states. The reverse osmosis process is not maintenance free. Thermal desalination processes thermal desalination processes volume 1 no. Thermal analysis of the recirculation msf system 3. Low temperature thermal desalination lttd is one process that uses the availability of a temperature gradient between two water bodies, such as the ocean thermal gradient that describes temperature variation across the depth of the oceans, to obtain fresh water. Pdf conventional low temperature thermal desalination lttd uses ocean thermal temperature gradients to drive a single stage flash distillation. Economic analysis for the entire process was compared with and without tes tank.
The combined systems of abhp with thermal desalination have been studied by many researchers, and some of the studies focusing on the abhpmee systems are. However, data from the inventory shows that the thermal market has continued to grow. The base method for sea water desalination is distillation. Thermal desalination thermal processes, except freezing, mimic the natural process of producing rain. A small temperature gradient of about 810c, as is the case with most power plants, would be. Desalinating sea water with low temperature technology. Low temperature thermal desalination lttd is a desalination technique which takes advantage of the fact that water evaporates at lower temperatures at low pressures, even as low as ambient temperature. These processes include multistage flash msf, multipleeffect distillation med, vapour compression vc and low temperature evaporation lte.
Library of congress catalog card number 86600507 for sale by the superintendent of documents u. The strongest point of the pro hybrid system with thermal desalination process is the higher temperature of the draw solution, which is the brine solution from the med, beside the swro hybrid system. The capacity of the plant is 1 lakh liter per day lpd. Reverse osmosis ro and nanofiltration nf in relation to thermal processes, reverse osmosis ro is a relatively new process that was commercialized in the 1970s buros, 2000.
Pdf a novel approach to low temperature thermal reverse. Study on the performance of natural vacuum desalination system. Congress, office of technology assessment, using desalinationtechnologies for water treatment, otabpo46 washington, dc. Titans low temperature thermal desalination plant operates utilizing flash evaporator, main condenser, vacuum pumping system, fresh water and warm water pumps. Design and simulation of seawater thermal desalination plants nafey, ahmed safwat m. Pdf conventional low temperature thermal desalination lttd uses ocean thermal temperature gradients to drive a single stage. Thermal desalination water treatment bwa water additives. Heat transfer from the electric heater to the seawater is assumed to be free convection and give by. Lowtemperature thermal desalination lttd is a desalination technique which takes advantage of the fact that water evaporates at lower temperatures at low pressures, even as low as ambient temperature. Md can be attractive for industry when freecheap energy is available or md. This configuration enables saline water to be evaporated at nearambient temperatures under nearvacuum level pressures created by the barometric head without any mechanical energy input. In 2005, indias national institute of ocean technology niot, chennai, set up the worlds first low temperature thermal desalination lttd plant at kavaratti in the largely coral lakshadweep islands off the.
Md is a developing technology that uses lowtemperature thermal energy for desalination. Low temperature thermal desalination titanium tantalum. Performance analysis of evaporationfreezing desalination system by humidity differences gaopenghui a,b. Elsayed 1994 a desalination primer,balaban publishers m. Hanbury w t and hodgkiess t 1995 desalination technology 95. Low temperature geothermal resource assessment for. Despite the rise of membranedominated markets such as algeria, spain and australia, thermal technology continues to. Use of lowtemperature geothermal energy for desalination. Solar thermal desalination technologies request pdf. Using desalination technologies for water treatment. An overview of solar thermal desalination technologies i. Solar energy has a very promising role to play in addressing water scarcity problems through. Isbn 9789533073118, pdf isbn 9789535145165, published 20110228 the book comprises 14 chapters covering all the issues related to water desalination.
The system uses the natural effects of gravity and atmospheric pressure to create a vacuum in which water can evaporate and condense at lower temperatures than normal for. Convective heat transfer coefficient between the water surface and the glass cover. Producing fresh water from seawater is made simple with the efficient, costeffective and economic titanlttd process technology. All types of solar thermal desalination technologies are presented in detail to enable readers to comprehend the subject, from design details to. Aly proposed a configuration composed of a singleeffect librh 2 o abhp and a 20effect ltmee with an evaporation temperature range of 663 c, and predicted a performance ratio. These chapters emphasize the relationship between problems encountered with the use of feed water, the processes developed to address them, the operation of the required plants and. Low temperature thermal desalination plants onepetro. Low temperature desalination using solar collectors.
Thermal desalination technology nrg expert energy expert. Methods and systems presents numerous thermal seawater desalination technologies varying from the very simple, easy to construct and operate solar stills, to the more advance membrane and indirect distillation methods. Thiruvananthapuram evaporating and condensing sea water at low temperatures to remove salt offers the best way to provide drinking water in indias coastal areas, says a new study. The lowtemperature distillation method of desalination developed by the new mexico state university nmsu in the usa has been licensed to sterling water llc of qatar. Performance limits and opportunities for low temperature. The experiment system of evaporationfreezing desalination is shown in fig. Darwish,iain mcgregor 2005,thermal desalination processes,fundamentals and practice,five. Thermal desalination lttd is one process that uses the availability of a temperature gradient between two water bodies, such as the ocean thermal gradient that describes temperature variation across the depth of the oceans, to obtain fresh water. Vacuum systems for low temprature thermal desalination lttd first ever floating barge mounted low temperature thermal desalination plant by indian scientists water seems to be a superabundant natural resource on planet earth. One of the advantages of the process is that it can be implemented even with a low temperature gradient of about 810c between the two water bodies. Water is the most important chemical component on earth. Normally, seawater is fed to the desalination plant from about 50 m off. Lowtemperature distillation technology licensed to sterling. Evidence of greek sailors, in the 15th century, using solar distillation equipment to convert the seawater into freshwater has been reported.
Low temperature thermal desalination plantsthat use the ocean thermal gradient between surface water and that at about 400 m depth were established at kavaratti, agatti and minicoy islands in the. A reverse osmosis desalination plant with a capacity of 3000 m 3. While the temperature difference in the ocean drives distillation and provides cooling in lttd, external electrical energy is required to pump the water streams. Jan 15, 2016 thermal thermal desalination exploits the fact that water molecules vaporise at a lower temperature than dissolved salts and other molecules. Demont is among the most qualified suppliers actives in the international market, in position to design and supply desalination plants of last generation. Water desalination technologies utilizing conventional and.
Low temperature thermal desalination it is used on many seagoing ships and submarines. Thermal desalination an overview sciencedirect topics. Highlights a new low temperature desalination process using solar collectors was investigated. Vacuum systems for low temprature thermal desalination. Thermal desalination distillation involves a phase change, while membrane processes are single phase. Low temperature thermal desalination india infoline. In 1996, the total capacity of thermal desalination represented about 70 percent of the world total of seawater desalination plants. And the cooling water temperature is an important factor of fresh water yield. European desalination society genoa university courses in. Demont operates in the thermal desalination plants with its own proprietary technology and knowhow, through a dedicated business unit with the prestigious brands reggiane and sowit, pioneers in desalination industry since almost 50 years. Abstract a lowtemperature phasechange desalination process configuration is presented in this study. An overview of solar thermal desalination technologies.
Low temperature thermal desalination lttd is a desalination technique which takes. Low temperature thermal desalination lttd ministry of. To demonstrate low temperature desalination ltd unit at freshwater production rates 75100 gald to demonstrate twostage low temperature desalination unit to study the process variables such as heat and mass transfer coefficients, areas, scaling and fouling issues to determine the specific energy requirements for a two. The low temperature distillation method of desalination developed by the new mexico state university nmsu in the usa has been licensed to sterling water llc of qatar. Thus, because of the reduced pressure, lowtemperature waste heat from electrical power generation or.
Efficient thermal desalination technologies with renewable energy. Solarpowered desalination system for offgrid water production in india and gaza. Design and simulation of seawater thermal desalination plants. Thesystem is mainly composed of a constant temperaturetank1,anevaporationfreezingchamber2,twoaxialfans3,a low temperature dehumidi. T 1988 design and simulation of seawater thermal desalination plants. Solar thermal technology belongs to a class of systems which involve the capture of solar radiation for the delivery of useful thermal energy internal energy or enthalpy, and include. Desalination is a sustainable answer to the problems of limited access to fresh water and bwa is proud to have been providing water additives for use in thermal desalination processes since 1973. Accordingly, the best integration approaches use thermal desalination technologies such as multieffect distillation med or membrane distillation md. Theoretically, the new thermal seawater desalination technology can make full use of heat compared to existing ones. Since solar desalination plants are characterised by free energy and insignificant operation cost, this. In 2005, indias national institute of ocean technology niot, chennai, set up the worlds first low temperature thermal desalination lttd plant at kavaratti in the largely coral lakshadweep islands off the coast of kerala state in the arabian sea. Low temperature desalination using solar collectors augmented. Low temperature thermal desalination lttd process utilizes the temperature gradient between two water bodies to evaporate the warmer water at low pressures and condense the resultant fresh using the colder water to obtain high quality fresh water.
June 1819, 2012 thermal desalination june 20, 2012 material selection in desalination june 2122, 2012 water management and economics. Desalination is a process that takes away mineral components from saline water. A 6078% water production increase over a standalone ltmee run at the same heat source conditions can be obtained owing to the coupling. Demont has developed an innovative application for thermal seawater desalination plants, focused to the production of desalinated water distilled water, within industrial complex at zero primary energy cost, through waste heat recovery, also as method for energy efficiency improvement. Thermal desalination is a complex process with many potential pitfalls. Environmental impact of seawater desalination plants i. Low temperature thermal desalination lttd process utilizes the temperature gradient between two water bodies to evaporate the warmer water at low pressures and condense the resultant fresh using the colder water to obtain high quality fr. Khan school of engineering and technology, central queensland university rockhampton, queensland 4702, australia email.
Use of lowtemperature geothermal energy for desalination in. The main challenge facing thermal desalination processes is scale formation by inversesolubility salts. Ida desalination yearbook 20102011 conventional wisdom in the industry says that thermal desalination is in terminal decline. To reduce the thermal impact of a desalination plant, different discharge arrangements have been used. If we dont want to run out of water, we should look to the sun. Thermal transmission and water evaporation and condensation are physical laws that restrict the new thermal seawater desalination technology.
Desalination using solar energy is an ancient method of producing freshwater. The temperature range in question is not well suited for electricity generation, but can be used for direct heating. The main problems with the use of solar thermal energy in large scale desalination plants are the relatively low productivity rate, the low thermal efficiency and the considerable land area required. Lowtemperature distillation technology licensed to.
This study presents a thermal and economic performance analysis of a ltmee lowtemperature multieffect evaporation water desalination system coupled with an librh 2 o abhp absorption heat pump. Solar collector area and tes volumes were optimized by theoretical simulations. Low temperature geothermal resource assessment for membrane. Low thermal temperature desalination lttd low temperature thermal desalination lttd process utilizes the temperature gradient between two water bodies to evaporate the warmer water at low pressures and condense the resultant fresh using the colder water to obtain high quality fresh water. Abstract a low temperature phasechange desalination process configuration is presented in this study. Low temperature thermal desalination plants request pdf. Conventional low temperature thermal desalination lttd uses ocean thermal temperature gradients to drive a single stage flash distillation process to produce pure water from seawater. Md is a developing technology that uses low temperature thermal energy for desalination. Pdf vibration analysis of shell and tube heat exchanger. Vacuum systems for low temprature thermal desalination lttd. The hp absorbs energy effectively from low grade heat source then transfer the energy to the droplets.
Saline water is heated, producing water vapour that in turn condenses to form distilled water. Despite the rise of membranedominated markets such as algeria, spain and australia, thermal technology continues to be adopted on a large scale. Thermoeconomic analysis of a lowtemperature multieffect. Low temperature thermal desalination lttd the lttd technology was also demonstrated using waste heat from the north chennai power plant and produced fresh water. Solar thermal technologies for seawater desalination. The saline water is fed to vaporizer from feed tank by reducing the ambient pressure to an extent such that the saturation temperature corresponding to low pressure is below the saline water. Temperature difference between the fresh water and seawater is the key influencing.