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Environmental challenges in the energy sector a chemical engineering perspective.

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ASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING
Asia-Pac. J. Chem. Eng. 2010; 5: 553–562
Published online 4 May 2010 in Wiley InterScience
(www.interscience.wiley.com) DOI:10.1002/apj.436
Special Theme Review
Environmental challenges in the energy sector: a chemical
engineering perspective†
Philippe A. Tanguy*
Corporate Scientific Development, Total SA, 2 Place Jean Millier, 92078 Paris La Défense, France
Received 22 January 2010; Revised 9 February 2010; Accepted 11 February 2010
ABSTRACT: The supply of energy in sufficient quantities and the access to clean water are among the most significant
global challenges to address in the decades to come, as these are key elements of human well-being and further
development. These challenges are of course related, and future practices must consider their connectivity. As the
present energy system is clearly reaching its limits in terms of sustainability, new approaches have been proposed
based on much improved energy efficiency, development of renewable and new energy sources, and the use of carbon
capture and storage for fossil resources. The industrial deployment of these alternate scenarios is intrinsically related to
the availability of water on a large scale. Because the access to freshwater is becoming scarce in many countries, better
water practices and the exploitation of new water resources must be developed for the supply of industrial water. This
paper begins with a brief description of our present energy system based on fossil resources, this being a legacy of the
industrial revolution. We then review the main drivers supporting the energy and water demand, and the constraints
they are facing. The final section considers several chemical engineering challenges that arise when proposing ways
of dealing with the energy-environment nexus in the future.  2010 Curtin University of Technology and John Wiley
& Sons, Ltd.
KEYWORDS: energy sources; water resources; energy utilization; water reuse; carbon capture and storage (CCS);
sustainability
ENERGY LANDSCAPE
The supply of hydrocarbons to meet the global demand
is ensured for the century. The latest estimates[1]
recalled in Fig. 1(a) shows that the oil reserves amount
to 40 years. Reserves climb to 70 years when extra
heavy oil is included and even more when considering
oil shales.[2] Gas reserves (Fig. 1(b)) are at least of the
order of 60 years at the present rate of consumption,[3]
and new resources can also be exploited like gas shales
an natural gas hydrates in the longer term. Data for coal
as a primary energy are less accurate but the supply is
guaranteed for at least 150 years.
When a projection is made to Year 2030 (Fig. 2), an
oil production ceiling is appearing within a decade. This
levelling trend has two origins: one is a general underinvestment in production capacities by oil-rich states
in the recent past, and the other is an increasingly
*Correspondence to: Philippe A. Tanguy, Corporate Scientific
Development, Total SA 2 Place Jean Millier, 92078 Paris La
Défense, France. E-mail: philippe.tanguy@total.com
†
The ideas proposed in this paper were first presented as a keynote
address at the CHEMECA 2009 Conference in Perth, Western
Australia.
 2010 Curtin University of Technology and John Wiley & Sons, Ltd.
complex geopolitical landscape that limits new production opportunities by international oil companies. As a
result, the present production rate of about 84 Mbl/d
should barely reach the 100 Mbl/d mark as shown in
Fig. 2.[4] . Figure 2 also shows that the relative share of
fossil fuels will only drop by 6% in the next 20 years.
The differential energy demand is expected to be met
mainly by gas and coal and more marginally by other
energy resources, such as wind/solar, hydro, biomass
and nuclear. A thorough change of the energy mix in
the foreseeable future is not expected due to built-in
inertia of the energy system, and the world economic
development will still heavily rely on non-renewable
resources from primary energy supply in 2030. For this
reason, R&D efforts must be intensified to develop new
energy technologies less dependent on classical fossil
resources. It should be highlighted that this analysis was
carried out before the financial and economical crisis,
and it assumes that there will not be an impact on the
long-term energy demand.
The present energy system is inherited from the
industrial revolution.[5] It is based on fossil carbon,
trapped as coal, oil or gas, and uranium. When carbon
reacts with air during combustion, CO2 is released and
554
P.A. TANGUY
Asia-Pacific Journal of Chemical Engineering
754
367
222
36
14
62
128
Europe
463
North America
126
123
FSU
94
99
48
42
Africa
Central and South
America
Asia
Middle-East
300
250
200
150
100
50
0
North America
Central & South
America
Europe & FSU
Africa/MEA
Asia
Figure 1. (a) Oil and gas reserves in GBoe and (b) coal reserves in Gtons.
Figure 2. Energy supply trend analysis.
ultimately accumulates in the atmosphere. The relation
between this carbon footprint and climate change is
now well established, as highlighted by the work
of the Inter-government Panel on Climate Changes.
Figure 3 provides a view of the risks and results of a
 2010 Curtin University of Technology and John Wiley & Sons, Ltd.
global temperature increase.[6] The often mentioned 2◦
temperature increase scenario shows consequences that
are believed to be manageable. At this level, however,
some countries are already severely hit by the sea rise
due to unfavourable geography (low lands). Beyond
this 2◦ increase threshold, predictions show a dramatic
rise of risks of acute health problems, hunger, draught
episodes and water shortage, which would be much
more difficult to control.
As conventional oil production will not be sufficient
to meet the energy demand, a large-scale exploitation
of unconventional hydrocarbons is very likely in the
future. The two unconventional ‘liquid’ hydrocarbon
resources that can be considered are oil shales and oil
sands. The exploitation of gas shales is also turning
into reality. Oil shale is clay-like material containing
organic matter called ‘kerogen’. As this unfinished oil
lacks 60 million years to reach ‘maturity’, processes are
developed to bridge this gap. No large-scale commercial
exploitation of oil shales exists now but several R&D
efforts are being pursued. Oil sands are naturally
Asia-Pac. J. Chem. Eng. 2010; 5: 553–562
DOI: 10.1002/apj
Asia-Pacific Journal of Chemical Engineering
ENVIRONMENTAL CHALLENGES IN THE ENERGY SECTOR
occurring mixtures of sand, clay, water and bitumen.
The bitumen can be separated by processes that are
very similar to those of the mining industry, and
then upgraded to synthetic crude. Table 1[7] lists the
compositions of crude oil, bitumen (oil sands) and
kerogen (oil shales). Similarities between bitumen and
kerogen are striking, except that kerogen contains a high
level of oxygenates, which brings some challenges in
refining.
An alternative resource to meet the energy demand is
to resort to chemical conversion. Chemical conversion
can readily be applied to a wide variety of feedstock.
The generic term is XtY (X to Y) conversion, where the
feedstock X can be coal, gas, biomass, etc. The product
Y can be diesel and other fuels, e.g. methanol, hydrogen
or dimethylether (DME). Olefins can also be obtained.
Several conversion processes have been developed
as depicted in Fig. 4. For DME, direct conversion
is also possible. The various biomass valorization
pathways are detailed in Fig. 5. Several chemical routes
are already widely industrialized as the production of
biodiesel through the trans-esterification of vegetable
oil and ethanol production by fermentation of sugars.
One important issue related to biomass is the huge
consumption of water. We will come back to this later.
It is clear from the above that several process/
feedstock scenarios are available to offset the anticipated relative decline of conventional oil production.
The processes are, however, more difficult to design and
their environmental footprint creates new challenges
that must be addressed prior to a large-scale deployment. Indeed, the production of the synthetic fuels
coming from the processing of unconventional hydrocarbon, the XtY routes and the conversion of biomass
all have a serious impact on CO2 emission and water.
The graph of Fig. 6 highlights the relative impact of the
various options and the proposed solutions for remediation, namely carbon capture and storage and water
management.
Table 1. Comparison of oil, bitumen and kerogen
properties.
Crude Heavy
oil
oil
Bitumen Kerogen
Specific gravity
C
H
N
S
O
H/C
Heating value (MJ/kg)
0.85
86
13.6
0.2
0.2
0
1.9
42
0.95
86.5
11.5
0.5
1
0.5
1.6
38
0.98
85.1
11.3
1.6
1.5
0.5
1.59
35
1
79
10
2
1
7
1.52
34
Malaria
Water Flooding
Hunger
Figure 3.
Anticipated consequences of climate changes (http://www.
greenpeace.org/raw/content/international/press/reports/millions-at-risk.
pdf, consulted on January 18, 2010).
 2010 Curtin University of Technology and John Wiley & Sons, Ltd.
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Asia-Pacific Journal of Chemical Engineering
Reforming
gasification
Methane
Hydrogen
Diesel
Naphta
Gas
Fischer
Tropsch
Coal
CO/H2
DME
Direct Synthesis
MeOH
Olefins
Fermentation – Distillation
Esterification – Hydrotreatment
Enzymatic Hydrolysis
Biomass
Biofuels
Figure 4. Chemical conversion pathways.
Biomass Conversion
Biochemical
Fat Chemistry
Thermochemical
Enzymatic Hydrolysis
Sugar, fermentation
feedstock
Fermentation using biocatalysts
(like yeast and bacteria)
Gasification
Syngas
Pyrolysis
Transesterification
Pyrolysis oil
Biodiesel
Fermentation products
Refining, chemical pathways
Biofuels, bioproducts, fuels, hydrogen,…
Figure 5. Biomass valorization pathways.
CARBON CAPTURE AND STORAGE
Carbon capture and storage (CCS) process technology
involves four stages, namely the capture of CO2 , its
compression, its transportation by pipeline and its
storage or reuse. The more costly part is the capture,
which has been recently estimated at about 150$/ton
for a typical amine absorption separation process by a
Harvard Kennedy School team.[8] A decrease by 50%
is expected but this still represents a significant cost.
Several alternatives to standard amine absorption have
been proposed, which are all the subject of R&D work,
namely:
– Using new specially designed amines with a more
favourable Henry’s law constant for post-combustion
capture.
– Using sorbents like zeolites, high porosity metal–
organic framework and amine-coated sorbents also
for post-combustion capture.
 2010 Curtin University of Technology and John Wiley & Sons, Ltd.
– Membrane technology.
– In-process capture through chemical looping or oxycombustion.
– Capture by hydrates, photosynthesis or cryogenics.
Figure 7 illustrates the CCS platform designed and
operated by Total SA in Lacq, France. This RD&D
pilot uses an oxy-combustion technology implemented
in a 32-MWth steam boiler fed by natural gas coming
from the Lacq field. The purpose of this facility started
recently after a long societal and regulatory concertation
process with local and national stakeholders, is to inject
120 kT CO2 at 87% purity in a depleted gas reservoir.
The reservoir is located 4500 m deep underground. The
entire CCS facility is fully instrumented such that CO2
fugitive emissions if any can be detected and fixed. The
region surrounding the injection well above the storage
reservoir is also thoroughly monitored. This platform is
one of the very few demonstrations of the feasibility of
geological storage, and it is the first one in Europe. It
Asia-Pac. J. Chem. Eng. 2010; 5: 553–562
DOI: 10.1002/apj
Asia-Pacific Journal of Chemical Engineering
ENVIRONMENTAL CHALLENGES IN THE ENERGY SECTOR
Low
Adv.
biofuels
H2O use
GTL
CTL
Oil sands
Oil shales
Conv.
biofuels
High
High
Carbon Capture and Storage
CO2 atmospheric emissions
Low
Water management
Figure 6. Synthetic fuel production impact on CO2 and H2 O.
Figure 7. Lacq’s CCS pilot.
will serve as a R&D tool to improve CCS technology
as well better evaluate the true economical feasibility
of CCS with geo-storgae.
WATER CHALLENGES IN ENERGY
PRODUCTION
Water and energy are inter-related:
(1) Energy is required to produce water. Examples
include the treatment of drinking water, wastewater collection and pollution treatment, water lifting
from aquifers and pumping for transportation and
distribution in pipes. Water desalination, an increasingly important process to supply fresh water has
also a strong energy footprint.
 2010 Curtin University of Technology and John Wiley & Sons, Ltd.
(2) Water is needed for energy production. It is used
to grow energy crops, for conditioning coal (prewashing step) and inside process for cooling purposes, among others. Water consumption can vary
significantly and the actual water footprint will
depend on the source of energy and the valorization
process used.
The issue of water footprint is a complex one that
incorporates four dimensions: quality, quantity, geographical distribution and time scale. It is important
to make the distinction between the water supply by
withdrawal from rivers or aquifers, the water net consumption (‘lost’ by evaporation or underground penetration), and the water discharge. The water footprint also
involves a geopolitical dimension as its impact can be
felt only locally, at the basin level or at a much broader
international scale.
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generation biofuels and nuclear energy, the reality of
the data is very different. With the former one, most
of the water is used to grow the crop and ultimately
vanishes by evaporation or underground. Only a tiny
fraction (1%) is used in biorefining. For nuclear energy,
water is used for cooling and is returned to the river. It
should be noted that with the advent of 2nd generation
biofuels (non-food crops and cellulosic residues), water
consumption is expected to be significantly reduced.
As seen in Fig. 8(a), at the global level, water is
primarily used for agriculture and then for domestic and industrial use.[10] Projections to 2025 show a
significant increase in water demand by all sectors,
the agriculture sector still dominating by far due to
the further development of irrigation. Water consumption (losses be evaporation or underground drainage)
is very significant in agriculture and amount to almost
90% of withdrawal. Better irrigation practices like the
use of sprinklers and drip irrigation should be able
to improve the water use. For domestic and industrial
Table 2. Water consumption in energy production.
Water intensity (m3 /MWh)
Fuel source
Natural gas
Tar sands
Fischer-Tropsch
Coal
Liquefied natural gas
Ethanol
Nuclear
0.038
0.19–0.49
0.53–0.775
0.53–2.1
1.875
32.4–376
31–750
Table 2 lists typical values of water intensity in
energy production.[9] Conventional (liquefied natural
gas (LNG), coal and nuclear) and unconventional
resources (coal to liquid conversion, and exploitation
of oil sands) data are given along with those associated
with biofuel production. Figures are given in m3 /MWh
(1 MWh = 1.6 Boe). It can be seen that the range of
water demand is extremely wide. For the cases of 1st
3500
(a)
3000
2500
2000
1500
1000
500
0
Agriculture
Domestic
Industry
(b)
Figure 8. (a) Evolution of global water use (km3 ) from 1975 to 2025 (20 year
time interval) and (b) water poverty map. This figure is available in colour online at
www.apjChemEng.com.
 2010 Curtin University of Technology and John Wiley & Sons, Ltd.
Asia-Pac. J. Chem. Eng. 2010; 5: 553–562
DOI: 10.1002/apj
Asia-Pacific Journal of Chemical Engineering
ENVIRONMENTAL CHALLENGES IN THE ENERGY SECTOR
uses, water consumption is minimal and the problem
is rather related to water contamination and the generation of waste, as the amount of water to be treated
almost corresponds to water withdrawal. This creates
wastewater treatment challenges of a formidable amplitude and complexity. It is essential to properly manage
these three uses in a complementary way and not to
oppose them. It is however believed that the growth
in the water demand and water usage will force to
reconsider current practices so as to save this precious
resource.
It should be noted that, although a relationship exists
between the energy consumption per capita and the
gross domestic product (GDP) per capita, there is no
obvious link between the water consumption and GDP.
The complexity of the water use pattern is very high
and has not been really studied in depth so far.
The access to water, and even more so to clean water,
is linked to poverty. Although water has been considered as essentially a free commodity in the past, the
situation could be significantly different in the future,
especially in the countries the most adversely affected
by climate changes and an increased water stress. IPCC
models show that the already dry regions of the planet
(intra-tropical region) where poverty is concentrated
will get drier, with consequences that can be hardly
imagined.
A criterion, called the Water Poverty Index (WPI),
has been proposed, which is a complex relationship
incorporated resources, access, capacity, use and environment through the following relation[11] :
challenging: as domestic water supply is the obvious
first priority, the development of agriculture is problematic and so is industrialization. Aquifers are often
overexploited, which seriously hampers their sustainability. This typical situation may get more common due
to climate changes and highlights the importance of the
development of water resource management policies.
Population growth and sustained economic development are the two reasons underlying the development
of agriculture. Not only food consumption increases,
but food habits also evolve, in particular the consumption of meat. Table 3[14] gives the demand of water for
plant and animal products. The water footprint in food
production is clearly significant. When food is traded at
the international level, a large amount of virtual water is
displaced sometimes on very long distances. This hindered water trade has economic consequences as many
dry (and often poor) countries are encouraged to produce export food for rich countries, making them poorer
in terms of water resources for their own domestic use.
Coming back to water intensity in energy production,
although Table 2 data may suggest the opposite, global
water withdrawal for the production of biofuels from
agriculture (agro-fuels) still plays only a relatively
minor role. Indeed, the origin of water is not neutral, as
it may come from rain and/or from irrigation, and many
biofuel productions are rain-fed (palm oil in Indonesia
and Malaysia, sugarcane in Brazil) and rainwater can
be harvested.
In the energy industry, steam production and the
associated cooling process require a huge amount of
water. Figure 9(a) and (b) illustrates the two common
setups: the once-through steam plant cooling (Fig. 9(a))
and the recirculated steam plant cooling (Fig. 9(b)).
With the former type, water is withdrawn from the
river, goes through the process, is cooled down, then
some wastewater treatment is applied and the water
is then returned to the river. In this case, the water
use is very large (average 140 m3 /MWh), but the water
consumption is minimal (about 0.4 m3 /MWh). With the
second option, most of the water is recirculated and
cooled in a big tower, sometimes with forced air as
a cooling medium. With this approach, the amount of
water used is very small (5 m3 /MWh), but consumption
(water lost by evaporation) reaches almost 100%. As the
consumptive use is strongly affected by the selection of
the cooling system, an important effort must be made
WPI =
wr R + wa A + wc C + wu U + we E
wr + wa + wc + wu + we
where the coefficients wi are weighing factors, R represents Resources (availability of surface and ground
water), A represents Access (to safe water, sanitation and irrigation), C represents Capacity (income to
enable purchase, education and lobbying), U represents
Use (domestic, agricultural and industrial use) and E
represents Environment (related to local aqueous ecosystem).
Figure 8(b) illustrates the geographical distribution
of WPI.[12] A low WPI value indicates a high hydric
stress, which is usually related to the life expectancy
at birth. Although interesting for comparison purposes,
these average values give only a macroscopic view for
a given country and are insensitive to the strong differences that may exist within. The dramatic depletion
of the Ogallala aquifer in the southern part of central
USA coupled with its contamination by nitrates and
livestock feeding operations is an illustration of how
serious problems can be when the water use is not
properly managed.[13] In China, the northern part of
the country is suffering from a severe rainfall deficit,
whereas the southern part is prone to flooding. Consequences of a low WPI for economic development are
 2010 Curtin University of Technology and John Wiley & Sons, Ltd.
Table 3. Water use in raw food production (m3 /ton).
Plant
products
Vegetable oil
Rice
Corn
Vegetables
Water
consumed
Animal
products
Water
consumed
5000
1500–2000
700
200–400
Beef
Poultry
Eggs
Milk
13 000
4000
2700
800
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Figure 9. (a) Once-through cooling and (b) recirculating cooling.
when a cooling strategy is selected in a new process or
a plant, which must be adapted to the local conditions.
The common practice of resorting to pumping from
aquifers must be thoroughly evaluated due to its impact
on water supply for populations, in particular, the risks
of chemical or biological contamination.
As many oil fields are getting mature and therefore
produce a significant amount of water under the form
oil–water emulsion, the oil industry is actually the
largest producer and processor of water in the world. To
recover oil, the emulsion must be broken, the separated
water being treated to meet quality standards. Produced
water is often reinjected in the field, but it happens that
the water is also discharged in nature, which raises the
question of whether this water could be better valorized.
It is expected that industry and in particular the oil
industry will increasingly regard water as a strategic
resource.
WASTEWATER TREATMENT IN THE ENERGY
SECTOR
Wastewater treatment in the oil industry is a critical
subject, and the type of treatment must be adapted to
the oily nature of the waste. In terms of inventory,
at the upstream level, water is produced from wells
and surface separators, and wastewater is produced
from drilling operations and LNG plants. In refining
sites, process water comes from desalting, crackers,
distillation, hydro-treatment as well as deballasting
 2010 Curtin University of Technology and John Wiley & Sons, Ltd.
and tank drainage. Further downstream, the production
of petrochemicals requires process water and cooling
water, which contains chemicals. The treatment to apply
depends on the nature of the wastewater. For that
reason, wastewater can be classified as oily or non-oily.
Oily water comes mainly from the process, the produced
water and surface runoff. Non-oily water originates
from cooling, boiler blowdown, condensates and noncontaminated runoff.
Figure 10 shows a diagram of water treatment in
energy production. Depending on the process at hand,
the nature of the contaminants generated is very diverse,
including polycyclic aromatic hydrocarbons (PAH),
benzente-toluene-ethylbenzene-xylene (BTEX), metals,
phenols, chemicals, bacteria, enzymes and hydrocarbons. One major difficulty to handle is the variability
in terms of composition, concentration, temperature and
flowrate of the wastewater streams. At present, it is
extremely difficult to establish upper bounds for concentration for every contaminant, and only a few critical
ones are usually monitored. The most common practice is to track the evolution of global criteria like total
organic carbon, pH, suspended solids, to name a few.
Because of the intrinsic link between the quality of
discharge and the quantity of water handled, the main
challenge is clearly to reduce the water demand.
Modern wastewater treatment can be seen as a
juxtaposition of technology building blocks that can
be grouped in four categories: aerobic/anaerobic fermentation, membrane reactors, membrane separators
Asia-Pac. J. Chem. Eng. 2010; 5: 553–562
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ENVIRONMENTAL CHALLENGES IN THE ENERGY SECTOR
Figure 10. Wastewater treatment in energy production.
and evaporation/crystallization. As wastewater treatment uses lot of energy, energy efficiency is a major
issue to address. Another issue is the elimination or at
least the neutralization of the highly concentrated waste
residues being produced from these processes. As their
effects on the ecosystem are unknown, the minimization
of the residue quantity is also an important target.
Treated water leaving the wastewater plant must meet
regulations in terms of chemical and biological toxicity.
Beyond addressing the ecological and chemical status of
discharge streams, more work is needed to understand
the true impact of exit streams on the environment and
the biodiversity. What is the fate of the trace elements
and their impact on bioaccumulation, especially when
they may combine with trace elements emitted by other
industries in the same area?
Wastewater treatment in the energy industry is still
very challenging. Stricter and stricter standards pushing
the concentration level down to the limit of detection
make sampling, measurement, and therefore the establishment of species mass balance uncertain. Similar
to the impact of CO2 and its global warming potential, it would be useful to derive a water quality index
with some sort of impact criterion. Conductivity, total
organic carbon and turbidity are good starting points
but more specific indices will be needed in this area.
Another important issue is the management of unforeseen spot emissions, whether originating from storms,
extreme weather or accidental spills. The objective
should be to develop very flexible processing routes
that allow treating wastewater that follow the ‘business as usual’ expectations, and also those coming from
unusual circumstances. Efforts are also needed on the
economic side in terms of cost reduction of chemicals,
the disposal of sludge, energy efficiency, environmental
footprint (local constraints or more global regulations),
 2010 Curtin University of Technology and John Wiley & Sons, Ltd.
spatial footprint (modularity or compactness) and the
cumulative effect on the local or regional ecosystems
of multiple sources.
THE ROLE OF CHEMICAL ENGINEERING
The key to sustainable industrial water management is
not only looking at surface water and ground water
quality, catchment rights and flows, but also paying
attention to key drivers, namely:
(1) water disposal, recycling, and treatment,
(2) water demand versus seasonal and climate variations in supply,
(3) process water availability, handling and reuse,
(4) water consumption and use in energy generation,
(5) long-term impact to water after site closure.
Addressing these drivers will require innovative R&D
work that can be translated into better processes, products and practices. The development of new technologies to improve the treatment of contaminated water
is essential but not sufficient. Responsible methods to
dispose the removed contaminants must also be found.
To reduce the water footprint of the energy industry,
the recycle/reuse of lower quality water, process water,
industrial water coming possibly from other companies
around and even municipal water provides options to
consider, while keeping the treatment to a minimum
acceptableness (for instance, use of grey water in cooling). Cross-industry and municipality/industry cooperative use of water is seen as a very promising avenue to
minimize the water footprint of an industrial park.
Technically, the reduction of water footprint can be
obtained by reworking the processes with a new look
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assisted by accepted methods of process integration
and optimization, such as water pinch analysis, which
had their roots in energy optimization. Examples of
successful redesign of industrial plants that reduce
water make-up and effluent load provide incentives.
One example is the water closure in pulp mill.[15] A
second recent example is the redesign of a refinery water
circuit to decrease the water footprint.[16] The reduction
of evaporative cooling losses is also part of the same
optimization efforts.
To address the key issue of sustainability, life-cycle
analysis driven R&D work is needed to model the
overall system dynamics behaviour outside the plant
boundary, as well as developing new tools that can help
assess and analyse risks to the environment. A holistic
approach is essential in order to capture the possible
effects on the whole ecosystem.
CONCLUSIONS
Addressing the energy–water nexus provides outstanding R&D opportunities for chemical engineers. New scientific advances and disruptive technologies are needed
in cooling, desalination and separation. Advanced process integration methods must be developed to better
optimize the existing plants.
The ‘smart management’ of water and energy is a part
of the more global interdisciplinary field of industrial
ecology,[17] which is mainly concerned with tracking
flows of substances and materials in industrial activities in order to reduce their environmental impact. This
relatively young science is a fertile research land for
chemical engineers, where the fundamental study and
training includes mass and energy balances, transport
phenomena, optimization and control. With environmental system analysis and complex system thinking,
all these ingredients can be utilized to improve our interactions with nature and to reduce the water and energy
footprints of human activities on the environment.
 2010 Curtin University of Technology and John Wiley & Sons, Ltd.
Asia-Pacific Journal of Chemical Engineering
REFERENCES
[1] BP, Statistical Review on World Energy, 2009; http://www.
bp.com/productlanding.do?categoryId=6929&contentId=
7044622, consulted on January 21, 2010.
[2] P. Pouyanne. Journées annuelles du pétrole, AFTP, Paris,
2008; jdp.ecritel.net/Presentations/documents/Pleniere 1/2 P.
Pouyanne.pdf, consulted on January 21, 2010.
[3] World Energy Council, 2006; www.sourcewatch.org/index.
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DOI: 10.1002/apj
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