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Keeping you informed about the Eco-Cement project. Issue 20 1 June 2002

Understanding Carbon and Oxygen Cycles

Figure 0- Contributions to Atmospheric Carbon Dioxide  (from the Woods Hole Institute Web Site

Rising atmospheric carbon dioxide concentration and its potential impact on future climate is an issue of global economic and political significance. Of possible even greater importance is the depletion of Oxygen in the atmosphere.

Carbon dioxide is currently around 370 ppm whilst oxygen is just over 20 %. Nitrogen is ubiquitous at around 78%. Both carbon and oxygen are present in a combined form because of their importance in reduction and oxidisation processes.

The Carbon Cycle and the Impact of TecEco Technology

The Carbon Cycle is a complex series of processes through which many of the carbon atoms in existence rotate and in this article an attempt to explain it and the potential impact of the TecEco technology could make

Carbon is a major courier of energy. Plants capture energy from the sun using the photosynthesis process as a result of which carbon is fixed in their structures. Animals consume food produced in this way releasing the stored up energy and CO2. We also burn what was once living to obtain energy and release CO2.

Living plants and the geological remains of living plants and animals are major reservoirs of carbon. While there is considerable debate about the magnitude and location of these sinks, there is strong evidence that they are very significant.


We release large quantities of carbon dioxide by burning fossil fuels – according to the Wood’s Hole site on the internet  “The concentration of CO2 in the atmosphere has already increased by about 30% since the start of the industrial revolution sometime around the middle of the 19th century and will continue to increase unless societies choose to change their ways.” We are also destroying the living carbon sink by manipulating of the land surface for settlement, food and energy production, and water management.

Carbon dioxide is a major greenhouse gas and the continued release has resulted in a rise in the temperature of the earth’s surface, disruption in climates and as a result agriculture and caused a small rise in sea level due to the melting of ice.

According to the Wood’s Hole Institute web page[1] “Most of the increase in atmospheric CO2 concentrations came from and will continue to come from the use of fossil fuels (coal, oil, and natural gas) for energy, but 20-25% of the increase over the last 150 years came from changes in land use, for example, the clearing of forests and the cultivation of soils for food production.”

Numbers in the Carbon Cycle













Figure 1 - The Carbon Cycle (From from Schimel, et al. 1995. CO2 and the carbon cycle.)

Summary totals presented by the Wood’s Hole Institute for carbon in the carbon cycle during the decade ending 1990 (in billion metric tonnes or petograms) are:

Atmospheric increase


Emissions from Fossil fuels


Net emissions from changes in land use


Oceanic uptake


Missing carbon sink










Converting to CO2 in the same units this is:

Atmospheric increase


Emissions from Fossil fuels


Net emissions from changes in land use


Oceanic uptake


Missing carbon sink

12.07 (±0.73)


20.152 (±0.1.83)


5.86 (±2.56)


7.32 (±2.93)


6.59 (±4.39)

In general agreement with other research there appears to be a discrepancy which is believed to be because there has been a greater than measurable amounts taken up by living plant sinks (We may also be increasing the overall size of our atmosphere! – ed.)

Figure 2 - Sequestration and Emission of Carbon Dioxide (from the Woods Hole Institute web site).

The Impact of TecEco Eco-Cement Technology

TecEco cements are a system of blending reactive magnesia, Portland cement and usually a pozzolan in a number of different proportions depending on the properties required. Two main formulation groups have so far been developed. TecEco modified Portland cements containing much more Portland cement than reactive magnesia for durability and rheological improvements and TecEco Eco-Cements for lower emissions, fire resistance and a number of other advantageous properties. In both formulation groups the reactive magnesia first hydrates to brucite (magnesium hydroxide) and in Eco-Cements it further carbonates forming magnesite and hydromagnesite.

Around 98% of the world’s energy is derived from fossil fuels that when burnt to produce energy release vast amounts of CO2 and the production of Portland cement clinker, lime and magnesia all produce energy

The production of Portland cement, lime and reactive magnesia also results in the release of chemically bound CO2

The built environment is our footprint on earth. Buildings account for 30% of the raw materials used, 42% of the energy, 25% of water, 12% of land use, 40% of atmospheric emissions, 20% of water effluents, 25% of solid waste and 13% of other releases[2][3]. Include infrastructure and the numbers are more. Reducing the embodied energy and improving the durability of the built environment will reduce it’s impact on earth systems.

As some of my early calculations were incorrect, how these releases are abated in TecEco modified Portland cements and Eco-Cements has been updated in this article.

TecEco Modified Portland cements

TecEco modified Portland cements are much more durable because brucite is so much less soluble, mobile or reactive than Portlandite. TecEco modified Portland cements are not attacked by salts, they maintain the passivity of steel and can be used with a wider range of aggregates. As a result concrete structures built using modified Portland cement containing a small proportion of reactive magnesia as well as fly ash should last a lot longer and need replacing less often using less energy to remove them, less energy to waste them (a high proportion of urban waste is discarded building materials) and less energy to reconstruct them. As energy given scale is directly related to CO2 emissions, net emissions are lower.

TecEco Eco-Cements

TecEco Eco-Cements differ in that they produce less net emissions because they reabsorb CO2.

The easiest way to understand them is to think about a 1:1:7 , opc, lime and sand mortar in which there is a little less Portland cement and in which the lime is replaced with a bit more reactive magnesia which first hydrates and then carbonates. Toss in a bit of fly ash for good measure as it is a nuisance waste and to consume the lime. Magnesite is a strong often fibrous and acicular mineral and definitely worth encouraging in a binder. What follows is a bit more scientific explanation.

A mole of both magnesite and limestone, being carbonates will on calcination chemically release a mole of carbon dioxide and a mole of the respective oxides and hydroxides will reabsorb a mole of the gas. Table 1 below shows that more CO2is chemically released on a tonnes CO2/tonne product basis for both the calcination of magnesite and limestone than the production of Portland cement clinker and this is because the share of lime in Portland cement is only 65.5%. It is also true that on a mass basis, more CO2 is also chemically released by the calcination of magnesite than limestone, and this is because of the lower molecular weight of magnesium.

Portland cement as it hydrates produces around 24% lime (often referred to in the cement industry as Portlandite Ca(OH)2). In Eco-Cements relatively large proportions of reactive magnesia are blended with Portland cement and pozzolans and the magnesia hydrates first to become brucite (Mg(OH)2 and in permeable materials like bricks, blocks, pavers, mortars and possibly even highway and footpath pavement (for which it is suggested Eco-Cements should be used[4]), virtually all of the brucite and lime (unless the latter is consumed by a pozzolan) will reabsorb CO2 out of the atmosphere and eventually reconvert to their respective carbonates completing what are thermodynamic cycles. As a result net emissions are less. The proportion of materials, and in particular reactive magnesia, that will carbonate in Eco-Cements is much higher, so much more CO2 is reabsorbed.

Process emissions for cement manufacture are the emissions from the energy used in mining, transport, mixing, homogenising, grinding, preheating, calcining, finish inter grinding, packaging, transport and warehousing etc. The process emissions from the production of lime and Portland cement are slightly less when measured relative to the products than those for the production of reactive magnesia. On a per mole basis the production of magnesia is however more efficient.

What is important is that the sequestration by carbonation in the thermodynamic cycle magnesite=>magnesia=>brucite=>magnesite is potentially substantial and therefore represents a very useful way to create more sustainable building materials, particularly if the CO2 produced during calcining could be captured during the manufacturing process as TecEco propose to do with their new kiln[5]. The main technical requirement is that reactions in the system occur quickly enough[6].

Relative to Product

From Process Energy Release 100% Efficient

From Process Energy Release with Inefficiencies

From Chemical Release

Total CO2 100% Efficient

Total CO2with Inefficiencies

Total CO2 Released (tonnes/tonne)          













Portland Cement






Table 1 - Emissions from Magnesite, Limestone and Portland Cement

Given the huge size of the materials flows required to create and maintain the built environment the substitution of pure Portland cements by Eco-Cements on a widespread scale could result in massive abatement, particularly with capture of CO2 during manufacture.

To understand the huge scale of possible abatement and sequestration consider a typical concrete made with 15 mass% Portland cement compared to a concrete made with 15 mass% Eco-Cement that could be used for permeable masonry products such bricks, blocks, pavers and mortars as well as possibly highway and footpath pavement[4] and hence carbonate. Of the Eco-Cement 25 mass % is Portland cement, 75 mass % is reactive magnesia as shown in Figure 1. Assume the Portland cement on hydration produces 24 mass % Portlandite.

Figure 1 - Emissions With and Without Capture CO2 from Eco-Cement Compared to Portland Cement - The determination of a figure of .140 and .241 tonnes CO2 to the tonne net emissions from the production of reactive magnesia after carbonation (with and without capture of CO2 ) is complex and has been done on the basis all factors being the same for the production of magnesia as for the production of Portland cement other than the calcination energies[7].

The figure for the CO2 emissions from the production of Portland cement blocks used in calculating the numbers shown in Figure 1 of .896 tonnes CO2 to the tonne of cement is in broad agreement with the figures of Hendriks C.A. et. al. in an IEA paper[8] The lime produced as Portland cement used in permeable materials sets is assumed to totally carbonate and results in net emissions of .78 tonnes CO2 to the tonne of cement. The 15% Portland cement concrete in the above example has net emissions of .299 tonnes to the tonne. The Eco-Cement formulation in the above example on the other hand has lower net emissions of .241 tonnes to the tonne. With capture of CO2 during the manufacturing process which is relatively easy for the production of reactive magnesia, the figure for net emissions drops to a low .140 tonnes CO2 to the tonne of cement.

Because of the high molecular weight proportion of CO2 in MgCO3, and low temperatures involved, in the long run, as existing cement plants that could be converted to the manufacture of reactive magnesia are decommissioned, the manufacture of reactive magnesia using a new 25% more efficient TecEco kiln design (patents pending) in which CO2 is captured during calcining and grinding and sold for other purposes would be economically feasible. If sustainable energy were used to power the new kiln that does not release CO2 such as from wind power then Eco-Cements could even become a net carbon sink.

The use of fly and bottom ash, in which the energy costs are already accounted for in the power industry would also reduce net emissions as some process energies such as for mining would not be included.

In summary the potential for sustainability by changing the materials flows involved in the construction of our built environment, which represents our footprint on earth, is enormous. Buildings and even roads could be built using Eco-Cements of similar composition to the above example. After all the weakest part of multi story building today currently built of brick is the mortar in between which seldom exceeds 12 mpa and even that is probably more than necessary with good design. The only downside is that to gain full strength, carbonation must occur and this takes some time.

Consider the abatement, if the above formulation of 15 mass% Eco-Cement was generally adopted for 80 % of construction purposes (With no fly or bottom ash as there would not be enough!).


No Capture



Total Portland Cement Produced Globally
billion tonnes
Concrete with same Proportion (15 mass% cement)
billion tonnes
Emissions Portland Cement
billion tonnes
80% Substitution by Eco-Cements
billion tonnes
Abatement Portland Cement Emissions
billion tonnes
Emissions Substituted Eco-Cement
billion tonnes
Abatement by Substituting Eco-Cement
billion tonnes


Table 2 - Abatement from Substitution of Portland Cement by Eco-cement

Abatement without capture is .289 billion tonnes and with capture of CO2 during manufacture is 1.532 billion tonnes. If fly and bottom ash were used the figures would be higher at 1.5 billion tonnes and with capture of CO2 during manufacture, 2.75 billion tonnes. Fortunately there is not enough fly and bottom ash as the emissions from their production are accounted for in relation to the energy produced by burning coal.

Realistically there would also be considerable substitution replacing clay bricks, steel and aluminium used in construction because TecEco Eco-Cement concretes would be the first building materials devised of high thermal mass and low embodied energy. The cement industry should therefore see the production of Eco-Cements as an opportunity, not a threat[9].

Leaving out timber used in the built environment because it is a relatively short term sink, Table 3 sets out TecEco's estimates of global markets, the percentage substitution (assuming a mass for mass basis) and abatement worked out using a similar analysis to the above.



World Market

(Millions of Tonnes)

Substituted Tonnes (millions of tonnes)

CO2 Factors[10]

Emission from Material Before Substitution

Emission/Sequestration from Substituted Eco-Cement (Tonne for Tonne)

Net Abatement (Millions of Tonnes)


Emission - No Capture

Emissions - CO2 Capture

Abatement No Capture

Abatement CO2 Capture

Bricks 85%

250 [11]


.28 [12]






Steel 25%

840 [13]


2.38 [14]

499.8 56.56 29.38 443.24 470.42



20.5 [15]


18 MtCO2 t-1 [16]














Table 3 - Abatement from Substitution (MtCO2 t-1,millions of tonnes)

A further 518.21 or 573.42 billion tonnes would be sequestered depending on whether CO2 is captured at source or not. Total sequestration if Eco-Cements were adopted for 80% of the current uses of Portland cement could therefore be as high as 2.105 billion tonnes.

Further sequestration would result from the inclusion of waste carbon based matter including sawdust, waste timber shavings and chippings, plastics, rubbers etc, many of which are currently burnt adding to the global atmospheric CO2 level. Many of these materials will add strength to Eco-Cement products as they have innate tensile strength. Wood for example is in the order of 250 mpa whilst some waste plastics are closer to 1000 mpa. The figure is impossible to calculate because of the variation that may be expected, but would be in the order of more than .5 billion tonne.

With the inclusion of materials containing carbon the total abatement from the widespread adoption of TecEco Eco-Cement technology could therefore be as high as more than 2.5 billion tonnes. As the annual atmospheric increase in CO2 is around 12.7 billion tonnes[17] this would be over 15 % of the annual increase.

As Fred Pearce reported in New Scientist[18] “There is a way to make our city streets as green as the Amazon rainforest. Almost every aspect of the built environment, from bridges to factories to tower blocks, and from roads to sea walls, could be turned into structures that soak up carbon dioxide- the main greenhouse gas behind global warming. All we need to do is change the way we make cement” The TecEco cement technologies therefore merit serious attention by industry and governments as they represent a way forward for the Kyoto process.

Oxygen Depletion?

Oxygen is ubiquitous at around 47% by weight of crustal earth. Like carbon it is substantially present in a combined form because of their importance in reduction and oxidisation processes.

There is a lot of it – some 600 moles above every square metre and 250 moles below in the oceans.

The stoichiometry of the reaction

C (organic, inorganic etc.) + O2 « CO2

Suggests that with the burning of fossil fuels the level of oxygen in the atmosphere should be declining and this is the case according to recent studies, such as conducted by Ray Langenfelds from CSIRO Atmospheric Research which showed a .03% reduction in just 20 years using air samples taken from Cape Grim in remote Western Tasmania. The level as at the date of the study was 20.92%, down from 20.95% 20 years earlier.

According to scientist Richard Matear from CSIRO marine a recent series of experiments showed a decline in the level of oxygen at between 500 and 1500 metres in samples taken from the Aurora Australis between Tasmania and Antartica.

The decline at about .0015% (or about 3 ppm out of 209,500 ppm) per year is very slight and much less than the stoichiometry of the above equation predicts and this is thought to be because of biological catch up.







Figure 3 - Oxygen Depletion (Unofficially obtained data from a high latitude site - no references available!)

The figure given in most text books for the level of oxygen in the air is 20.95%, however studies supporting this were conducted prior to 1965. In pristine and isolated places the figure today is more like 20.92% as found by- the CSIRO in remote western Tasmania. In more populated areas where land has been cleared the average figure has fallen to more like 19% or 20%. In some cities (where the majority of the world’s population live) the level is even lower due to consumption, higher levels of CO2 and pollution and figures as low a 12-18% have been recorded. As 7% is considered starvation level and some 90% of the world’s population live in cities this is concerning.

What is the optimal level of oxygen? Field geologists have found that the evidence from small pockets of air trapped in fossilised amber that the level of oxygen some 80 million years ago was somewhat higher at around 30% - was that an optimal level and has it been falling since then?

More research obviously needs to be done in this area and made public. It is also important when considering emissions and sequestration to not only consider the affects on CO2 emissions but on O2 deletion as well.

TecEco Can Make it To Johannesburg!

I found the following press release send to me by a friend at Ethical Investor Magazine very interesting. Note the comments about a sustainable cement initiative. We need all our friends to help us get there!

Press release from: World Business Council for Sustainable Development:

Sustainable Development is Serious Stuff for Industries

(CSRwire) GENEVA, Switzerland - 'Sector projects', a new WBCSD brochure, outlines the groundbreaking work carried out by six industry sectors toward sustainable development. It is being launched today in Bali during the fourth and final Preparation Committee for the upcoming World Summit on Sustainable Development.

Bali, May 28, 2002: Sustainable development is too big for companies to handle individually, regardless of their size. By working together in sector projects, companies can achieve more than they would alone, shows a new report released today by the World Business Council for Sustainable Development (WBCSD).

The WBCSD's six sector projects, led by member companies, look at the sustainability performance and challenges for the whole value-chain of an industry sector. They harness independent research, stakeholder consultations and partnerships into how a particular industry can contribute to sustainable development. The ultimate purpose is to change industry practices and policies to make them more sustainable.

"These projects are not trying to develop industry positions. Each goes well beyond the normal confines of industry," said WBCSD president Björn Stigson. "We deliberately seek external inputs, including substantive funds from industry and non-business sources, to ensure that proposals developed are not 'industry solutions' only."

The project philosophy is based on the participatory concept, bringing together stakeholders with widely differing views, and seeking to build partnerships between industry, government and other institutions to identify ways forward. The purpose is to make the findings and conclusions supported and relevant to the broadest possible spectrum of companies, from all regions, at all stages of economic development.

The six WBCSD sector projects are:

The progress these sector initiatives demonstrate is valuable for the upcoming World Summit in Johannesburg because it shows that companies can come together to tackle long-standing, difficult dilemmas.

For more information please contact:

Genevičve Tremblay

WBCSD Communications


(+41) 22 839 31 08


Some Interesting Quotes From the WBCSD

The following were scrolling on the WBSCD – Towards as Sustainable Cement Industry web site at http://www.wbcsdcement.org/

Concrete is second only to water as the most consumed substance on Earth, with almost one ton of it being used for each human every year, reports French cement maker Lafarge.
Globe and Mail, October 20, 2000

Concrete paving eats traffic pollution. Titanium dioxide-containing paving blocks use sunlight to absorb nitrogen oxides in the atmosphere and converts them into harmless nitrogen and oxygen.
Concrete quarterly, August 2000

World production of cement is 1.56 billion metric tons. One third of this is produced in China alone.
USGS Minerals information.
Cement statistics. 2000.

Annual global production of concrete hovers around 5 billion cubic yards.
Cement Association of Canada.

In 1824, Joseph Aspdin, a bricklayer in Leeds, England, took out a patent on a hydraulic cement that he called portland cement because its color resembled the stone quarried on the Isle of Portland off the British coast.
Cement Association of Canada

Cement, an ultra-fine gray powder, binds sand and rocks into a mass or matrix of concrete. Cement is the key ingredient of concrete.
Cement Association of Canada

Twice as much concrete is used in construction around the world than the total of all other building materials including wood, steel, plastic and aluminum.
Cement Association of Canada.

Supplementary cementing materials such as fly ash and slag - have the potential to substantially reduce CO2 emissions over current practices.
Canada, Office of Energy Efficiency, November 15, 1998 Vol. II No. 22

In manufacturing 1500M tonnes of Portland cement each year worldwide, an equivalent amount of CO2 is released into the atmosphere.
Center for Contaminated Land Remediation

Cement kilns have been identified as a stationary source that emit more than 25 tons of nitrogen oxides (NOx).

Carbonaceous material used for making cement releases significant amounts of CO2 in creating the final product.

The Superiority of TecEco Second Generation Magnesium Cement Technology Compared to Sorel Cement Technology

I have written this article because a number of people have asked me why TecEco cements are superior for many applications in comparison to Sorel type cements[19]. These enquiries have come from as far away as Singapore and the US and often from people associated with proponents of Sorel type technologies, disclosed or otherwise. In later editions I will address our superiority for certain applications over Portland cements and geopolymers (this will make for interesting reading!).

A number of companies in Australia are marketing first generation Sorel cements with secret formulae, patents not registered in Australia and so on and claiming them to be the panacea for waste fixation etc. Some are not even disclosing the cements as being of Sorel type and this is very misleading. Sorel type cements are not suitable for waste fixation in the longer term for a number of technical reasons discussed below.

A large number of leading scientists in the field of Sorel cement technology that we are in contact with agree that, as Stanislas Sorel noted in 1867, the cements have a remarkable capacity to bond with and contain other materials[20] This outstanding capacity is also a feature of our second generation magnesium cements.

Sorel technology is limited however in that:

The cements are subject to phase changes to weaker forms. To prevent this, great precision is required in formulation. This can be particularly difficult once wastes are introduced. For example, in some cases the 5 form phase of magnesium oxychloride is transformed at later stages to the 3 form phase with mechanical strength decrease.

·       The cements themselves are layered structures which exfoliate and release environmentally undesirable salts The risk of breakdown makes Sorel type cements unsuitable for toxic and hazardous waste immobilisation given the longer term.

·       Sorel cements are made by adding salts and the technology is well known. These salts can however be as undesirable as many of the wastes claimed to be encapsulated by the proponents of the cement. Salt leaching also makes Sorel type technology unsuitable for longer term metallic reinforcement.

Scientific consensus is that carbonation protects Sorel type cements against further breakdown. Many have recognised this in both secret and patented formulations. However, as Cole and Demediuk[21] noted in 1955, the carbonation of magnesium oxychlroide, to form magnesium chlorocarbonate, for example, is a long and very slow process.

Our second generation magnesium cement technologies overcome all the difficulties of first generation Sorel type cements and they carbonate much more rapidly.

Magnesium cements have a terrific future, but not in the waste industry with the addition of mobile salts, proprietary, secret or otherwise.

First Commercial Blocks

The first blocks for commercial use were ordered by James Morrison and Yvette Breytenbach Architects Pty Ltd of Hobart for a house in Hobart and made on the Tuesday 21 May 2002 at Breadlebane near Launceston by Island Block and Paver Pty. Ltd.

According to masonry guru Bill Fawdry of Island Block and Paver they went through the block machine very well on a day when making blocks had not been easy.

We are expecting them to take a month or so to really get hard but when they do they will be just as strong as blocks made with three times the amount of Portland cement in them. This makes them very environmentally friendly. What is more the total Eco-Cement content was less than the cement that would normally have been used in a lightweight block.

Lower Share Price Brings New Strategic Shareholders

Two new shareholders have joined the company since the last newsletter. One is a scientist with excellent credentials and a penchant for writing and the other an economist who also has keen skills with the pen. May the pen is mightier than the sword!!

We are keen for people who may have a strategic interest in what we are doing to contact us. At the moment we are trying hard to raise funds so we can pay the patent fees to secure as many countries as possible. If you are thinking of joining us – now would be a good time!

Ken’s Column

Eco-cement.  A better cement.  A cheaper cement.  A more environmentally friendly cement.

Let’s get that message out to the world!

There is a very high latent demand for Eco-Cement because the world is forever looking for better products, cheaper products and more environmentally friendly products.

We have to turn that latent demand into real commercial demand.

We need cement manufacturers and cement users who are not only interested in Eco-Cement: we want them to back their curiosity with money.

That’s when the dollars will start flowing: when we have manufacturers and users lined up insisting on having the technology.

Eco-cement is not just an interesting idea:  it is a fantastic business opportunity.

The way to turn latent demand into real commercial demand is to tell everyone about the benefits of Eco-Cement.  The more the better, though we need to be targeted because time is precious.  So do please tell them:

Eco-cement - better cement!

 - cheaper cement!

-        more environmentally friendly cement!

Anyone know a good jingle? - (editor)

JJ’s Column[22]

I am in the process of re-writing TecEco’s website with PHP-based server side programming. This will help make TecEco’s web page easier to update and iron out some problems.

The top number of referrals this month came from ON LINE opinion (file:///C:/Inetpub/wwwroot/TecEco/bin/Newsletters/www.onlineopinion.com.au)

I am in the process of creating a new website to help widen the debate on sequestration  (removing CO2 from the air). Everyone is encouraged to become involved - not just big corporations. The central theme will be broadening the debate to include other than just forestry. By the next newsletter the site should be up and running at www.CO2Busters.org

Because the website is in the process of being re-written updates are being made but not necessarily uploaded. They are as followed:

EcoFlex (http://www.ecoflex.com.au) has been added to the links page and additions have been made to the chronological history page.

Editorial Policy

Because the editorial staff (*!?*) at TecEco are very busy many of our articles ask more questions than they answer such as the articles on carbon cycles and oxygen depletion in this newsletter. We hope however that they make you think, and if you do any research to answer your enquiring minds – please send it on to us if it is of value!

[1] http://www.whrc.org/science/carbon/carbon.htm

[2] Australian Federal department of Industry Science and Tourism, Environmental and Economic Life Cycle Costs of Construction, 1998 - Detailed Discussion Paper, (section 2 - page 8)

[3] The reference given by Industry Science and Tourism was Worldwatch paper 124 How Ecology and Health Concerns Are Transforming Construction Worldwatch Paper 124 by David Malin Roodman and Nicholas Lenssen

[4] There is considerable merit to the argument that road and footpath pavement should be permeable to allow the earth to soak up rainwater replenishing aquifers rather than running off. See ecocreto.com

[5] Patents pending

[6] The kinetics of the reactions are a different aspect of TecEco technology and not considered here apart from reassuring the reader that low temperature calcined magnesia can be made reactive enough so that it hydrates sufficiently quickly as to not cause dimensional distress when blended with Portland cement.

[6] There is considerable merit to the argument that road and footpath pavement should be permeable to allow the earth to soak up rainwater replenishing aquifers rather than running off. See ecocreto.com

[7] Complex spreadsheets are available for scrutiny. We could do with some help to improve them!

[8] Hendriks C.A. et. al. in an IEA paper, C.A. Hendriks, E. Worrell, L. Price, N. Martin, D. de Jager, K. Blok, and P. Riemer, Emission Reduction of Greenhouse Gases from the Cement Industry. International Energy Agency Conference Paper at www.ieagreen.org.uk

[9] This is very basic economics. The industry are however one product focused and cannot yet understand the merit of diversification into Eco-Cement.

[10] Converted to CO2 from carbon using figures from the Woods Hole Institute at http://www.whrc.org/science/carbon/carbon.htm

[11] Dr Selwyn Tucker, CSIRO dbce. Published figures.

[12] This figure was derived from known figures in some countries.

[13] Dr Selwyn Tucker

[14] International Iron and Steel Institute figure at http://www.worldsteel.org/article/iisi20020118.

[15] Dr Selwyn Tucker, cross checked to AGO Australia data.

[16] International Aluminium Institute at http://www.world-aluminium.org/iai/stats/index.html

[17] Alan Pears, RMIT

[18] Articles have appeared in a diverse range of publications including New Scientist (Fred Pearce, "The Concrete Jungle Overheats", New Scientist, vol 175 issue 2351, 19 July 2002, page 39 and Tam Dalyell, "Westminster Diary", New Scientist vol 176 issue 2368, 09 November 2002, page 55), the Toronto Star, National Report, Saturday, July 27, 2002, p. F05, the CSIRO online Sustainability Newsletter and more recently in The Guardian (Owen Dyer, A Rock and a Hard Place, Eco-cement yet to cover ground in the building industry, The Guardian, Wednesday May 28, 2003) and Climate Change Management, June 2003 issue. A film about block making using the technology has been shown by Discovery Channel Canada and more recently in the USA. The technology also won the Tasmanian Innovation of the Year Award in 2002.

[19] Sorel cements do not include magnesium phosphate type cements which are of excellent quality, but will never be economic for large scale use as phosphates are becomingly increasingly expensive.

[20] See also Ramachandran VS, Feldman RF, Beaudoin JJ, Concrete Science – Treatise on Current Research, London, Philadelphia: Heydon, 1981.

[21] W.F.Cole and T.Demediuk, “X-ray, Thermal and Dehydration studies on magnesium oxychlorides”, Aust.J.Chem., 8(2), 234-51, (1955)

[22] For those who our wondering, JJ is John Harrison’s 13 year old son (yes JJ’s a teenager!) and TecEco’s webmaster and information systems manager.