Post on 20-Jan-2016
description
Les enjeux du dessalement de l’eau de mer
Mary-Fleur Tordjmann
Master 2 ILTS
2005 - 2006
Sommaire
• Introduction
• Présentation du domaine
• Arborescences
• Fiches terminologiques
• Texte de traduction
• Conclusion
Introduction
Why did I choose « seawater desalination: what is at stake? »
Water is vital to life.
Water covers about 75% of Earth’s surface, 94 % being salt water from the oceans and 6 % freshwater. (O.K. Buros, The ABC’s of Desalting, 2000)
The need of freshwater is increasing as the world’s population, industrialization and agriculture are growing. In 2005, the world’s population amounted to 6.5 billion people. (UN)
There is not a best desalination process. They all have advantages and drawbacks. So one of the questions is: which of the desalination processes is more appropriate?
Seawater desalination: definitions
What is desalination? A process that removes salts. Desalination can be found in nature through the water cycle.
Desalination is a term that applies to all processes which remove salts.
Seawater desalination: a brief history Seawater distillation desalination was known in
Antiquity.
The first industrialized distillation devices were found on steamboats in the 19th century. But real development dates back to the 20th century.
Research started in the 50s in the United States.
In 1952, the US government created the « Office of saline Water » while the French government created a Comity in 1966.
In the 70s, oil crises fostered investment by Middle-East countries.
400 AD (Desware Information Booklet, UNESCO)
Seawater desalination today Today industrialized desalination technologies are:
• Distillation: Multi-stage flash distillation; Multiple-effect distillation; Vapour compression distillation.
• Membrane: Reverse osmosis; Electrodialysis, only used to desalt brackish water.
Membrane vs. Distillation in the world: in 1998, reverse osmosis 42%, electrodialysis 6%, multi-stage flash distillation 44%, Multiple-Effect distillation 4% and vapour compression distillation 4%.
Reverse osmosis
(Introduction to Desalination Technologies in Australia, AFFA, 2002) (Desware Information Booklet, UNESCO)
Multi-stage flash distillation
(Desware Information Booklet, UNESCO)
Multiple-effect distillation
(The ABC’s of Desalting O. Buros, 2000)
Vapour compression distillation
(Desware Information Booklet, UNESCO)
Seawater desalination: what for?
Seawater desalination aims at converting salt water to• Freshwater for: Agriculture; Industry;
• Drinking water for human consumption.
To be used by a growing number of countries.
Energy consumption
A lot of energy is needed to run a seawater desalination plant and depends on the process.
As a result, operating a plant is still expensive.
Using a lot of power has a negative environmental impact.
The environmental impact
A high energy consumption has an undeniable environmental impact.
It seems that there is discrepancy between French and English speaking countries’ points of view about the impact of the plant itself. It seems there are more texts about the negative impact of desalination plants in English texts.
Seawater desalination alternatives
Research is being conducted to try to find alternatives to reduce technical, environmental and energy drawbacks.
Today there are many alternatives more or less developed: • Freezing desalination for cold countries;• Hybrid processes i.e. the association of two desalination processes;• Membrane distillation;• Nuclear desalination;• Renewable energy powered desalination such as wave-powered
desalination, solar desalination, wind-powered desalination, cogeneration i.e. plant that produces energy while desalting seawater, etc.
At least 27 different desalination processes.
Which process to choose?
Many studies held in the world compare all the processes to determine which of them is the most appropriate depending in the situation.
One has to take into account:• Seawater parameters such as salinity, turbidity, temperature, etc; • Energy consumption and availability;• Technical requirements like pretreatment, equipment standards or
equipment deterioration;• Environmental impacts, that are more considered in the English
speaking countries.
Seawater desalination future
Today desalination is still under intensive research and new technologies are being developed.
Examples: French scientists have developed a new distillation evaporator in 1999. The world's low temperature thermal desalination plant designed by an Indian Institute opened in July
2005 on Kavaratti island, in India.
Expert
Author of my text:
Philip Davies
School of Engineering, the University of Warwick
Aston University, Birmingham
http://www2.warwick.ac.uk/fac/sci/eng/staff/ad/publications/
ArborescencesLégende
hyperonyme/hyponymes
tout/parties
cause/effet
opération/résultat
chronologiques
« rapport »
« apport de »
« risque de »
« détermine »
fiches longues
ayant arborescence termes
termes
« par phénomène de »
Liens Termes
liste non exhaustive
1 : Le dessalement
dessalement
dessalement des eaux saumâtres
dessalement de l’eau de
mer (2)
dessalementdes eaux usées
Légende
liens hyperonyme/hyponymes
termes
termes
termes à fiches longues
termes ayant arborescence
2 : Le dessalement de l’eau de mer
prise d’eau
dessalement de l’eau de mer
prétraitement
dessalement (procédés de) (3)
post traitement
distribution
eau de mer (12)
eaud’alimentatio
n
eau produite
saumure
eau douce
eau potable
énergie (4)
rejet
recyclage taux deperformance
(distillation)
tauxde conversion(osmose inverse)
Légendeliens hyperonyme/hyponymesliens opération/résultat
liens chronologiquesliens « apport de » liens tout/partiesliens « rapport »
3 : Les procédés de dessalement
Légende
termes procédés utilisés pour l’eau de mer
procédé de dessalement
hybride avec changementde phase
termes procédés non conventionnelspour eau de mer
membranaire chimique
échange d’ionsélectrodialyseosmoseinverse (5)
congélationdistillation (11)
liens hyponyme/hyperonymes
membrane (9)distillation
àmultipleseffets (6)
distillationpar
détentessuccessives (7)
distillationpar
compressionde
vapeur (8)
solaire
à longstubes
verticaux
à tubeshorizontaux
arrosés
effet
liens tout/parties
liste non exhaustive
thermocompressioncompressionmécaniquede vapeur
4 : Les types d’énergie pour le dessalement de l’eau de mer
type d’énergie
cogénération
thermal
électrique
renouvelable
nucléaire
distillation parcompression de vapeur (8)
distillation àmultiple effets (6)
distillation pardétentes successives
(7)
osmose inverse (5)
solaire
éolienne
des vagues
dessalement nucléaire
récupérationd’énergie
turbopompe
intégrée
systèmeà piston
turbinePelton
saumure
à cycle direct
à recirculation récupérationde chaleur
Légendeliens « apport de »
liens tout/parties
liens opération/résultat
liens hyponyme/hyperonymes
termes énergie pour distillation et osmose inverse
5 : Le dessalement de l’eau de mer par osmose inverse
pompehaute pression
module membrane (9)
eau d’alimentation
saumure
système derécupération
d’énergie
eau douce
Légendeliens « apport de »
liens tout/parties
liens chronologiques
liens hyponyme/hyperonymes
liens opération/résultat
6 : Le dessalement de l’eau de mer par distillation à multiples effets
vapeur 1er effet 2ème effet
vapeur
n effet
saumure
évaporation
condensation
condenseurfinal
eaud’alimentation
vapeur vapeur
cellule
échangeurde chaleur
Légende
liens « apport de »
liens tout/partiesliens chronologiques
liens opération/résultat
températurepression
liens« par phénomène de » liens cause/effet
températurepression
eau doucefluidechauffant
saumure
7 : Le dessalement de l’eau de mer par distillation par détentes successives
réchauffeur 1er chambre 2ème chambre
vapeur
n chambre
saumure
évaporation
eau douce
condensation
eaud’alimentation
vapeurvapeurréceptable
échangeurde chaleur
température
condenseurcondenseurcondenseur
réceptable réceptable
vapeur
eau doucetempératurepression
températurepression
Légende
liens « apport de »
liens tout/parties
liens cause/effetliens « par phénomène
de » liens chronologiques
liens opération/résultat
liens hyponyme/hyperonymes
8 : Le dessalement de l’eau de mer par distillation par compression de vapeur
échangeurrécupérateur de chaleur
eau d’alimentation
saumure
eau douce
évaporateur/condenseur
compression de vapeur
vapeur évaporation
eau douce
saumure
condensation
Légende
liens « apport de »
liens opération/résultat
liens « par phénomène de » liens chronologiques
9 : Les principales contraintes techniques liées à la membrane d’osmose inverse
membrane
polarisation
entartrage
colmatageencrassement
salissures
tartre
précipitation
réversible irréversible
gâteau
matières en suspension matières colloïdales
hydroxydede magnésium
sulfatede calcium
carbonatede calcium
silicatesde calcium
compactage
pression
Légendeliens « par phénomène de »
liens cause/effet
liens tout/parties liens hyponyme/hyperonymes
liens « risque de »
Fouling index
liens « détermine »
biofouling
eau de mer (12)
érosion corrosion
10 : Autres contraintes techniques liées au procédé d’osmose inverse
installation
Légende
liens « risque de »
liens cause/effet
normes
liens « détermine »
11: Les contraintes techniques liées au procédé de distillation
installation
encrassement entartrage
corrosion
érosion
Légende
liens « risque de »
liens hyponyme/hyperonymes
12 : Propriétés de l’eau de mer
propriétés del’eau de mer
turbidité
matières en suspension
selsdissous salinité température
liens hyponyme/hyperonymes
liens « détermine »
Légende
liste non exhaustive
Tree diagramsLegend
hyperonym/hyponyms
whole/parts
cause/effect
operation/result
chronological
« ratio »
« adding of »
« risk of »
« determine »
long records
with tree diagramterms
terms
« by a phenomon of »
Relations Terms
non exhaustive list
1: Desalination
desalination
brackish waterdesalination
seawater
desalination (2)
waste waterdesalination
Legend
hyperonym/hyponyms relations
terms
terms
terms with long records
terms with tree diagam
2: Seawater desalination
water intake
seawater desalination
pretreatment
desalination (processs of) (3)
post-treatment
distribution
seawater (12)
feedwater
product water
brine
freshwater
drinking water
power (4)
discharge
recycling performanceratio
(distillation)
efficiency
Legend
hyperonym/hyponyms relationsoperation/result relationsChronological relations
« adding of » relationswhole/parts relations« rapport » relations
entrainment impingement
cause/effect relations
plume
3: Desalination processes
Légende
terms processes use for seawater
desalination process
hybrid based on physical change
terms non conventional processes for seawater
using membrane chemical
ion exchangeelectrodialysisreverseosmosis (5)
freezingdesalination
distillation (11)
hyponym/hyperonyms relations
membrane (9)multiple-
effectdistillation (6)
multi-stageflash
distillation (7)
vapourcompressiondistillation (8)
solar
withvertical tubes
with fallingbrine film
with horizontalTubes with falling film
effect
whole/parts relations
non exhaustive list
thermal vapour
compression
mechanicalvapour
compression
4: The types of power used for seawater desalination
type of power
cogeneration
thermal
electrical
renewableenergy
nuclear
vapour compressiondistillation (8)
multiple-effectdistillation (6)
multi-stage flashdistillation (7)
reverse osmosis (5)
solarenergy
windenergy
waveenergy
nucleardesalination
energyrecovery
integrated turbopump
pistonspump
Peltonturbine
brine
heat recovery
Legend« adding of » relations
whole/parts relations
operation/result relations
hyponym/hyperonyms relations
terms power for distillation and reverse osmosis
solardesalination
wind-powereddesalination
wave-powereddesalination
5: Reverse osmosis
high pressurepump
membrane assembly membrane (9)
feedwater
brine
energy recovery device
freshwater
Legend« adding of » relations
whole/parts relations
Chronological relations
hyponym/hyperonyms relations
operation/result relations
6: Multiple-effect distillation
vapour 1st effect 2nd effect
vapour
nth effect
brine
evaporation
condensation
final condenser
feedwater
vapour vapour
vessel
heatexchanger
Legend
« adding of » relations
whole/parts relations chronological relationsoperation/result relations
temperaturepression
« by a phenomenon of » relations cause/effect relations
temperaturepression
freshwaterfluid
brine
7: Multi-stage flash distillation
brine heater 1st stage 2nd stage
vapour
nth stage
brine
evaporation
freshwater
condensation
feedwater
vapourvapourrecipient
heat exchanger
temperature
condensercondensercondenser
recipient recipient
vapour
freshwatertemperaturepression
temperaturepression
Légende
« adding of » relations
whole/parts relations
cause/effect relations
« by a phenomenon of » relations
chronological relations
operation/result relations
hyponym/hyperonyms relations
8: Vapour compression distillation
heat exchanger heat recovery
feedwater
brine
freshwater
evaporator/condenser
Vapourcompression
vapour evaporation
freshwater
brine
condensation
Legend
« adding of » relations
operation/result relations
« by a phenomenon of » relationsChronological relations
9: The main technical disadvantages of reverse osmosis membranes
membranescaling
fouling
scale
precipitation
biofilm
suspendedsolids
colloidalparticles
magnesiumhydroxide
calciumsulfate
calciumcarbonate
calciumsilicates
Legend
« by phenomon of » relations
cause/effect relations
whole/parts relationshyponym/hyperonyms relations« risk of » relations
biofouling
film
biological matters
non exhaustive list
« determine » relations
Fouling Index
seawater (12)
erosion corrosion
10: Other technical disadvantages related to reverse osmosis process
device
Legend
« risk of » relations
cause/effect relations
standards
« determine » relations
11: Technical disadvantages related to distillation processes
device
scaling
corrosion
erosion
Legend
« risque de » relations
hyponym/hyperonyms relations
12: Seawater properties
seawaterproperties
turbidity
suspended solids
dissolvedsalts salinity temperature
hyponym/hyperonyms relations
« determine » relations
Legend
non exhaustive list
Terminology problems
Difficult to select the terms.
Still not sure about the terms and their equivalents because the same word can be written in many ways. For example: Multi-Stage Flash distillation without upper case, freshwater in two words, desalination synonymous like desalinization, desalting (which is an old word), dessalement or désalinisation in French, acronyms for desalination processes such as reverse osmosis: RO, a shorter version of the terms like vapour compression distillation and vapour compression, etc.
Brine and concentrate vs. samure and concentrat.
Terms in British or American English?
The difference between French and English texts will oblige me to deal with terms without equivalent.
Literature searching problems
A lot of documents on the subject in English, from articles to reports, organizations, associations… and as a result it is difficult to select them.
The most interesting documents in French are books which take a
long time to deal with.
Wave-powered Desalination: Resource Assessment and Review of Technology
Wave-powered Desalination: Resource Assessment and Review of Technology
Text presentation
I found this text on the Internet. The text was actually published in
“Desalination” in the December 2005 issue.
A text which is renewable-energy-oriented because energy consumption is one of the major problems in seawater desalination. As a result, a lot of terms in the text do not directly belong to the subject area of my dictionary.
Desalination in the dictionary because it is crucial to understand
what it is about to comprehend the text.
Text sample
Wave-powered desalination: resource assessment and review of technology
Le dessalement• couplé à/associé à/généré par• l’énergie houlomotrice/l’énergie des vagues/l’énergie due aux vagues :
évaluation de la ressource et bilan de la technologie
Text sample
The second technology reviewed is based on the Salter duck. The duck was originally conceived at the time of the UK Wave Energy Program of the 1970’s and demonstrated that it was possible to achieve an efficiency of wave-energy extraction exceeding 80% using a single degree of- freedom mechanism [25,33].
La deuxième technologie traitée utilise le canard de Salter. L’invention de ce canard remonte à l’époque du Wave Energy Program britannique (un programme gouvernemental qui, en plein choc pétrolier, visait à utiliser l’énergie houlomotrice comme alternative) lancé dans les années 70. Ce nouveau système avait alors démontré qu’il était possible de récupérer 80% de l’énergie générée par les vagues en utilisant un mécanisme à un degré de liberté [25,33].
Text sample
The UK government did not pursue this or other wave technologies at that time. However, Salter later proposed a version of the duck for desalination, in which vapour compression equipment is actually housed inside the floating duck [34,35].
Mais, le gouvernement britannique cessa toutes recherches sur l’énergie houlomotrice. Cependant, plus tard, Stephen Salter proposa une version du canard conçue pour le dessalement dans lequel une installation de compression de vapeur est logé à l’intérieur même du canard flottant à la surface [34,35].
Text sample
Rocking motion will give rise to changes in water level inside the hull of the duck, generating pressures sufficient to drive evaporation and condensation across a falling-film heat exchanger. The process is designed to run at 100ºC, but the large size of ocean-going ducks (typically 6–12 m in diameter) will minimize heat losses.
Le hochement provoquera un changement du niveau de l'eau à l'intérieur de la coque du canard, générant assez de pressions pour que l’évaporation et la condensation se produisent en traversant l’échangeur de chaleur à film tombant. Ce procédé est conçu pour fonctionner à 100°C, mais la grande taille de ces canards de haute mer (en général 6-12 m de diamètre) permet de réduire les pertes de chaleur.
Conclusion
Many uncertainties remain.
Many details will probably be changed.