Covey Consulting News

Covey Consulting News
December 2011
Seasons Greetings
to all of our readers
The Covey Notebook
Items of interest from
Covey Consulting
Dennis Shore was recently an invited speaker at the 30th FAPPI Conference in Malaysia. FAPPI is the
Federation of ASEAN Pulp and Paper
manufacturers (Indonesia, Malaysia,
Philippines, Thailand & Vietnam) but
was also attended by contingents
from Japan, Korea & Taiwan , all of
whom presented country reports.
Dennis presented a paper entitled
“A Low or No Effluent Mill can make
Good business Sense”.
Although much of Asia has a high
rainfall, and indeed Thailand was
suffering extensive flooding, water is
scarce in many regions & the topic
was of considerable interest. Contact Covey Consulting if you would
like a copy of the presentation.
Please contact John Trewick
to learn more about
Radiata Bulletin
Water Purification Systems for
Remote Water Supplies
At this time of the year much of Australia goes into a dry spell.
Alan Harvey has been working on a
development with Melbourne com- This emphasises that desalination
pany, Aquamill to develop a novel processes exchange energy for wanew process to address this challenge. ter, thus contributing to greenhouse gases. This regrettable situaWater is the lifeblood of remote com- tion does not have an answer at
munities. Brackish bore water is often present but hopefully future techthe only source of supply. Methods to nologies may improve that situamake such water suitable for human tion. Nano-tubes hold out the posconsumption or fit for feeding farm sibility of providing a membrane for
animals are vital. Thermal methods RO which will reduce membrane
such as distillation may be used and pressure drop & therefore energy
Membrane based techniques may be costs.
applicable. Membrane based purifiThe following methods of purificaers using reverse osmosis (RO) are
tion will be discussed
widely used for city water supplies but
1.
Multi Effect Distillation
have major disadvantages for inland
2.
Flash Distillation
water supply purification. This article
3.
Reverse Osmosis
reviews the principal methods of water purification in relation to remote Multi Effect Distillation
community water supplies, including Assuming salt water as a typical
a novel high efficiency method based feedstock, in a classical distillation
on spray drying techniques and va- system, feed water heating by
pour compression developed
by steam or other means produces
Aquamill Melbourne.
water vapour or steam & an effluMethods of Water Purification ent liquid stream of stronger saline.
To the beginning of this millennium, The condensed steam becomes the
multi-stage flash & multiple-effect purified water product stream. In
distillation dominated technologies multi-effect evaporation, steam
for purification of brackish water. At from the previous evaporator is fed
coastal sites, reverse osmosis (RO) to the next evaporator as a heating
based techniques now dominate new medium for the incoming salt wainstallations for seawater desalina- ter. The steam from this effect then
tion. Large RO desalination plants are goes to the next effect. Thus 1 kg
in operation in WA, SA, Queensland, of steam can ideally produce N kg
the Gold Coast & many more are un- of product stream in an N effect
evaporator. For seawater applicader construction.
tions, salts start to precipitate out
Different considerations apply for at approximately 90% concentrainland remote communities which tion limiting recovery to less than
mean that thermal techniques will this percentage.
often be more suitable (sometimes in
conjunction with RO). For instance
certain elements & compounds found
in bore water may disable or diminish
the effectiveness of RO membranes
thus making their use unattractive. All
purification systems have the following basic architecture:
2
Operating pressure for subsequent
evaporation stages will lower progressively. The boiling point increases
with salt concentration & also the
energy required to evaporate a specified amount of water increases so
practical levels of recovery are of the
order of 80% of feed water volume.
Multi Effect Distillation systems commonly use a steam compression system or thermo-compression to provide an increase in the steam temperature and pressure. See below.
Vapour Compression is a simple
means of reducing thermal energy
required for evaporation of feed
stream in a distillation unit. In the
mechanical method, a compressor,
(commonly rotary, centrifugal or
axial flow) is used to compress vapour from an evaporator which then
provides higher temperature steam
for the heating of the inlet brackish
water stream. Due to the thermodynamic advantage of such a system,
heating requirements can be more
than halved by such methods. Temperature differences for such systems are limited to between 5.5 &
11 °C so initial costs of the evaporator will be greater due to the larger
surface area required for heating.
Against that, feed heating equipment & product cooling costs are
eliminated. In thermo-compression,
higher pressure steam is used with
an ejector nozzle to increase the
pressure & condensing temperature
of the steam.
with higher salt concentration. The
gaseous phase can then be condensed back to nearly pure water.
This process can be continued by
feeding the stronger saline to another stage at a lower pressure, producing more and more steam and
successively stronger salt solution.
Figure 3. Flash Distillation stage
Energy can be recovered by preheating the feed saline with the hot
exit strong saline in a conventional
heat exchanger.
Also energy can be recovered from
the steam by a similar means. With
a large number of stages, high fractions of water recovery are obtained. With a multi-stage system,
temperatures may range from 90°C
and 0.5 Atmosphere for the first
stage to 35°C and a pressure of less
than 0.05 Atmosphere for the last
stage. For an N stage system, heat
requirements are reduced from approximately 2.3 MJ/kg of evaporated water for salt water at low
concentration levels to an ideal
value of 1/Nth of that energy. This
is an oversimplification as the energy required for evaporation increases with salt concentration, rising to approximately 4.0 MJ/kg at
8% salt concentration. Note steam
injection is also commonly used to
provide vapour compression as an
alternative to mechanical compression methods.
Flash Distillation
Distillation methods all rely on a pure
gaseous phase, i.e. steam being produced by boiling the feed liquid by
thermal energy or at lower temperatures, by reduced pressure methods
& then condensing the steam back to
near pure water. In flash distillation,
the feed saline is compressed by
means of a pump & then allowed to
expand through a nozzle into a sepa- Reverse Osmosis Water Recovery
ration chamber. At the reduced pres- In reverse osmosis, (RO) near pure
sure, steam flashes off from the in- water is recovered by applying an
input feed at high pressure to a
feed solution leaving a liquid phase
semi-permeable membrane. Due to
osmotic forces, about 40-50% of the
input stream can be recovered on
the output side of the membrane,
leaving a relatively large outflow of
more concentrated saline, around
twice the inlet salt concentration.
For seawater, typical values would
be 3.5% for input concentration and
7% strong saline exit concentration.
Energy requirements compared
with multistage flash distillation are
less, making it the method of choice
when relatively low pure water recovery is acceptable, around 50%.
As a consequence of the low permeate percentage a large effluent
stream of strong saline results. In
coastal applications, the effluent
stream can be pumped back into
the sea. However in inland areas
this is not feasible.
A possible problem is fouling of the
membranes by heavy metals or certain types of organic matter, e.g.
oils. Membranes are typically cellulose acetate although many different materials are used in order to
provide resistance to fouling against
a number of specific contaminants.
Since the exit saline is at high pressure, it is common practice to pass it
through a turbine to recover energy
from it for assisting the feed pump
drive. Energy is of course still required to provide the high pressures
needed to drive the reverse osmosis
process.
For desalination, Inlet pressures are
of the order of 15 atmospheres for
up to 2% salt while pressures of
about 40 atmospheres are used for
sea water desalination.
Comparison of Recovery Methods
Reverse osmosis requires less energy per cubic meter of exit water
produced. However for inland use,
the disposal of an effluent stream of
the order of 50 % of the supply
stream is a major disadvantage.
(Ctd p. 7)
3
Chanukah – the Festival of
Lights
Christmas as we know is a time of celebration in the Christian calendar. These
days it often seems that it is a time of
great commercial celebration. As Martha and Nafty Vanderhoek explain
there is also an important celebration
in the Jewish calendar that falls around
the same time as Christmas.
BUT NO IT IS NOT THE JEWISH
CHRISTMAS
This is a common misconception, but
in reality the Jewish Festival of Chanukah has nothing to do with the Christian celebration. It is celebrated on
the 25th day of Kislev, according to the
Jewish calendar, which can fall any
time from late November to the end of
December.
The story of Chanukah goes back to
ancient times, to 165 BCE.
The Syrian King Antiochus the fourth
invaded Jerusalem & ordered the
desecration of the Temple which was
built by King Solomon. This was the
holiest site in Jerusalem so this was a
great blow to the Jews living there.
The intention was to virtually eliminate the practice of Judaism. To further humiliate & antagonise the Jews
Antiochus decreed that an altar to
Zeus (pagan god) be built and that pigs
(a forbidden food for Jews) should be
slaughtered at the altar.
There was great consternation amongst
the Jews as it would
take them several
days to either find
oil that was not
desecrated or to
make new oil.
In recent times, so that children do
not feel left out by the obvious gift
giving at Christmas, they are given
gifts.
There are eight candle holders in
each Chanukiah, including a special
one, usually raised or next to it
which is called the Shamash or the
attendant. It is only this special
candle that can be used to light
each candle for eight consecutive
days. The first night one candle is
lit, the second night two candles
and so on until all eight have been
lit. Three prayers are said at this
time and families usually sing songs
about freedom.
lovely brass Chanukiah that was
given to Nafty for his Bar Mitzvah
(13th birthday) and we use this each
year. Last year our granddaughter
made her own Chanukiah from bottle tops glued onto a wooden stand
which she decorated with coloured
paper and drawings (she was only
four years old) and proudly lit her
candles each night. She especially
enjoyed eating jam donuts.
It is traditional to place the Chunukah lights in a prominent position so
that all may see it (however, during
However, to their delight they the Spanish Inquisition, and during
found that there was sufficient oil other times when Jews were persefor eight days, allowing the lights to cuted, they used to light their canbe kindled. To celebrate this, Jews dles where no-one could see them).
all over the world light candles for In our family, Chanukah is celethe eight days of Chanukah.
brated simply. We have a very
Since gambling is allowed on Chanukah, many families play with a spinChildren usually make their own ning top called a dreidel.
Chanukiah and are often given
them as gifts.
Families celebrate this festival usually by eating foods that are cooked
in oil – very delicious jam filled
donuts which are then rolled in
sugar, and latkes, which are potato
pancakes cooked in oil.
Chanukah, like many of the other
Jewish Festivals, is a happy celebration shared with family and friends
and emphasises the importance of
family unity and the joy of living.
Antiochus, however, made a serious
mistake in this. A Jewish High Priest,
Mattitiyahu & his five sons organised a
revolt against the invaders, & successfully drove them out. This revolt was
led by one of the sons, Yehuda Ha
Makabi (Judah the Hammer) and plans
were made to rededicate the temple.
Oil was needed for the seven branched
candelabra, a Menorah that was lit in
the Temple every day. Since the Temple had been desecrated, the oil that
was available was not able to be used
to light the Menorah. Only one jar of
sealed oil was found and this was sufficient only for one day.
Families in different countries celebrate in differing ways. Some families give their children small gifts on
each night of Chanukah, others may
give “Chunukah Gelt” which is
chocolate money, and others may
not give gifts at all.
4
Tempting Potato
Geoff Covey seems to have an
endless repertoire of Christmas
recipes. This is one with a difference but could well be a great hit
as part of your festive feast.
Strangely for one who has worked
nearly 35 years in the pulp and
paper industry, until recently I
had never been to Sweden (and I
have still never been to Japan, but
with two children learning Japanese at school that will probably
change soon too). This year I
spent six weeks in southern Sweden & thoroughly enjoyed myself.
There were but two disappointments – I felt humbled by the fact
that teenage shop assistants
spoke better English than I do,
and I had great difficulty in finding
‘traditional’ Swedish food. We ate
fantastic pizzas and some of the
best Italian food I have ever had
(this from someone who took a
job at Melbourne University because of its proximity to Lygon
Street). We also ate lots of
smoked and salted salmon
(magnificent) and some beautiful
pickled herrings, but where were
the Smorgasbords? In our whole
trip we saw one restaurant offering them, and that didn’t start for
four hours by which time we had
to be in our hotel far away (and
were in fact eating another delicious pizza!).
Making smorgasbord at home
was not practical, but all our
guide books assured us that an all
-time favourite in Sweden was the
potato dish Jansson’s delight. Alas
we could find this no-where either, but I could get a recipe and
make it in our small flat – and it
was delicious.
I will share it with you and it can
go with hot or cold dishes during
your Christmas/New Year celebrations.
For four people you will need:
3 medium potatoes peeled and
cut into slices or strips, or
coarsely grated.
About 8 anchovies (if you don’t
like anchovies, you can use
smoked salmon, or even make it
fishless – it just won’t taste as
good – personally I use a whole
jar of anchovies, but I also like
anchovy pizzas).
A large onion, thinly sliced.
1 tablespoon of butter
1 cup breadcrumbs.
1 cup of thickened cream
Salt and pepper.
Soak the potatoes in cold water
for 10 minutes to remove surplus starch (you can omit this
stage if you like).
Sauté the onions until soft, but
not beginning to brown.
Layer the ingredients in a
greased casserole – the idea is
to have potatoes as the top and
bottom layer, and one or more
layers in between (how many
layers will depend on the size of
your casserole and the quantity
you make. Over each layer of
potatoes spread some onions
and anchovies and season with
salt and pepper.
Pour in cream until it comes
about ¾ way up the stack.
Melt the butter and blend in the
bread crumbs and then spread
this mixture over the top layer
of potatoes.
Into an oven at 220°C for 45-60
minutes and enjoy!
Rudolph the Red Nosed Reindeer
Almost every child in the Western World
knows the words & tunes to the song
about Rudolph. Surprisingly Rudolph
came out of nowhere & quite recently.
In 1939 Santas at
Montgomery Ward
stores gave away 2.4
million copies of a
booklet "Rudolph the
Red-Nosed Reindeer."
The story was written
by Robert May, a 34
year old employee in
the advertising department & the booklet was illustrated
by Denver Gillen.
Despite wartime paper shortages, over 6
million copies had been distributed by
1946.
The story was written in verse as a series of rhyming couplets & it is reported
that May tested the story on his 4-year
old daughter Barbara, who loved the
story.
There is quite a Hollywood Christmas
post-script attached to this story.
Sadly, May’s wife died around the time
he was creating Rudolph, leaving him
deeply in debt due to medical bills. However, he persuaded Montgomery Ward
to turn the copyright over to him in
1947, ensuring his financial security.
"Rudolph the Red-Nosed Reindeer" was
printed commercially in 1947 & in 1948
a movie cartoon of the story was created. May's brother-in-law, songwriter
Johnny Marks, wrote the lyrics & melody
for the song "Rudolph the Red-Nosed
Reindeer".
The Rudolph phenomenon
was
born when the
song was recorded by Gene
Autry in 1949 at
the urging of
Autry's wife. The
song sold 2 million copies that year, going on to become the second bestselling song of all time, after Bing
Crosby's "White Christmas".
5
Pinatubo
Reg Harvey provides us with another
unique analysis of an interesting
natural event for your holiday reading.
Volcanoes have been getting some
bad press lately. What with Ian
Plimer blaming all the CO2 rise on volcanoes, and the completely unpronounceable (& unspellable) volcano
in Iceland last year which disrupted
air travel in Europe for thousands of
passengers….. Even more significantly
from my point of view, it delayed the
playoff for the world chess championship by two whole days (the
champ was stranded in Paris and had
to drive to Bulgaria). Shocking.
However to return to the subject of
volcanoes, it is very popular nowadays to write letters to the paper restating the Plimer bit. I was recently
sent a copy of an email by someone
who was claiming that the Mt Pinatubo eruption in 1991 put more
CO2 into the atmosphere than all the
manmade (womanmade? personmade?) anthropogenic emissions
since time immoral. I did admire the
wording - it was a very well written
letter with a searing combination of
scorn and vitriol. If you log onto the
web, it only takes eight keystrokes to
check this claim (NOAA CO2) and see
that it is obvious rubbish. I wonder
why people with obvious talent write
such things … politics I suppose.
What I would like to do is give volcanoes a bit of a boost in the Damon
Runyon sense – or alternatively ‘I
come to praise volcanoes, not to bury
them’ to make an awkward pun.
The interesting thing about volcanoes
is that the big ones do actually have
measurable effect on the earth’s
temperature for a couple of years or
so – the problem for the extreme climate change deniers is that it reduces the temperature rather than
increasing it. This is because the ash
that is injected into the stratosphere
(or troposphere, or some such lofty
and elevated sphere) reflects some of
the light from the sun. Ditto for the
sulphurous gases that are also emitted into the whatever sphere it is and
are oxidised to what are tactfully
called sulphate particles - these are
even better at reflecting/absorbing
the light. Krakatoa cooled the earth
by about 1oC, and Tambora (1815)
cooled the earth by about double
this. Both of these resulted in crop
failures in both Europe and the US.
Not all big volcanoes cool the earth –
there are different types of volcanoes. In my view, the best way to
categorise them is by the opportunities they present for TV film crews…
which is, let’s face it, the closest you
and I get to see them. Although,
come to think of it, the wife did go &
peer at a rather considerate and low
key volcano in Vanuatu which threw
up the odd piece of red hot rock at
regular intervals for the tourists. She
says it was the highlight of her trip,
although I think it was because she
was chatted up by the local chief in
the guest house she was staying in.
The most common type of volcano
emits very large amounts of grey ash
– the more the better. The best camera angle seems to be from a plane,
but if the TV station is a bit strapped
for cash, then a long distance shot
from ground level is OK, especially if
it can be taken across water.
The second type go sort of glug glug
as in Hawaii where the molten lava
flows down the hill. It is well known
that these only occur at night where
the TV can bring out the orange red
glare more advantageously.
The third type involves very large
clouds of hot gas (& ash) which whips
down the mountain at great
speed & you see on the telly a
bloke in a white ute driving furiously in the general direction of
away. These are a bit risky to film,
but this can be easily averted by
reference to the archives. No one
has yet noticed that the licence
plate number on the ute is the
same irrespective of which continent the volcano is located in.
The fourth type (& far and away
the best) is/are? the ones that go
ka-blam of which the best known
would be Krakatoa in 1883. While
these obviously present the most
dramatic photo opportunities,
there do not seem to be too
many of these on the telly. And
(most reprehensibly) there were
no TV film crews at Krakatoa …
wimps I say, wimps the lot of
them.
And yet, and yet
Volcanoes can (quite possibly) be
bad for you & spoil your entire
day. The biggest mass extinction
known to science occurred 251
million years ago when 90% of all
species went extinct.
Also at 251 million years ago,
there was a massive type two volcano in Siberia. While it cannot
be proven that this caused the
extinction, the timing is an interesting co-incidence to say the
least.
Do not think I am joining the volcano gang of deniers – far from it.
The letter I referred to above
noted that the Mt Pinatubo eruption lasted a whole year. Wow!
The eruption in Siberia lasted for
a million years, & the lava covered an area of two million
square kilometres one kilometre
deep.
This is really a ‘Paul Hogan’s
knife’ type volcano ……..
Coming soon – “Climate Change
the Musical”. Watch this
6
space.
Christmas Around the World
(Ctd from P. 3)
In Australia Christmas is usually
celebrated according to English traditions. Even though there are
shared traditions & values around
Christmas celebrations there are
often significant differences.
In Sweden, December 13 commences Christmas festivities on St.
Lucia's Day, which celebrates the
patron saint of light. By tradition
the eldest daughter rises early &
dresses as the "Queen of Light" in a
long white dress & wears a crown
of leaves. Singing "Santa Lucia," the
Lucia Queen serves coffee & treats
to each member of the family.
If a multi-stage flash distillation system is used in conjunction with electricity generation, steam for distillation purposes may be available free
as a by-product of the steam turbine energy production cycle. In
this case, energy is not a problem
and the high water recovery is an
In Spain Christmas season begins advantage, since it also means a low
on December 8, with a weeklong effluent volume of high solids conobservance of the Feast of the Im- tent to dispose of.
maculate Conception. Churches &
outdoor markets are decorated Spray Drying Systems
throughout the Christmas season
Recently, a novel method of water
with evergreens. Tambourines,
purification has been developed by
gourd rattles, castanets, and miniaAquamill Melbourne. This method
ture guitars accompany the singing
sprays water into a process chamand dancing in the streets.
ber where it meets a counterIn The Netherlands, Christmas cele- current stream of high temperature
brations commence with the arrival steam. A concentrated impurity
of Sinterklaas December 6, St. stream is recovered by a mist elimiNicholas Day. Dressed in red robes nator & a fraction of the exit steam
& a pointed mitre on his head Sin- is taken off and condensed to proterklaas travels by ship from Spain duce very pure water. A thermal
to Amsterdam's harbor every win- compression system then raises the
ter with his white horse & a sack temperature of the remaining exit
full of gifts for children. Families steam to provide the high pressure
celebrate St. Nicholas Eve at home steam for the evaporation of the
with lots of good food, hot choco- feed droplets via a heat exchanger.
late, and a letterbanket, a "letter
cake" made in the shape of the first
letter of the family's last name.
In China to the few Christians there
Christmas is “Sheng Dan Jieh”, or
Holy Birth Festival. Homes are
decorated with evergreens, posters, & bright paper chains. Christmas trees, called "trees of light,"
are decorated with beautiful lanterns, flowers, & red paper chains
symbolising happiness. Red pagodas are pasted on the windows &
houses are lit with paper lanterns.
A 10:1 thermal advantage has been
obtained by this method. Using
thermal compression for heating &
heat exchanger systems means that
very good energy efficiencies can be
obtained. Aquamill have produced
a working plant using this system
and are currently investigating applications for this plant in remote
locations for water purification.
Conclusion
In most cases of brackish water purification, distillation or spray drying
methods give a high water recovery
and a low effluent stream. This outweighs the higher energy costs of
these methods compared with the
lower energy per cubic meter of RO
based methods. For inland use, the
disposal of an effluent stream of the
order of 50 % of the supply stream
for RO systems is a major disadvantage. Also organic and ionic materials in some brackish water streams
reduce the effectiveness of the RO
membranes, which means RO may
be impractical or costly due to
membrane replacement costs.
Thermal methods are capable of
handling higher levels of salt concentration Spray drying systems are
simpler than distillation systems giving considerable cost savings.
Acknowledgements
Use of notes from Dr Ron Zmood of
Aquamill is gratefully acknowledged.
7
Covey Consulting
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Intimate knowledge of Australian
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25 professionals, over 600 years total
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knowledge
The Covey team
Dr. Geoff Covey
Mr. Gerke Faber
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Chairman & chemical Engineer
Engineering Manager
Process Manager
Mr. Dennis Shore
Dr. Dennis Creasy
Mr. Roger Canty
Dr. Ajit Ghosh
Dr. Bruce Allender
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Mr. Alan Eagle
Ms. Jo-Ann Moore
Mr. Steve Grist
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Dr. Alan Harvey
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8