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Keeping you informed about the TecEco cement and kiln projects. Issue 43, 10th February 2005
John Harrison, the inventor of tec, eco and Enviro-Cements and managing director
of TecEco Pty. Ltd. has just won the 9th February episode of the New Inventors
broadcast across Australia.
John won unanimously with TecEco Eco-Cement which is a blend of reactive magnesium oxide (reactive magnesia) with conventional hydraulic cements like Portland cement.
The invention is of global importance because Eco-Cements set by absorbing CO2 out of the air and combined with kiln technology being developed by TecEco which captures CO2, could potentially turn the problem of global warming around.
John is determined to show that people care about the environment by winning
the New Inventors peoples choice.
Voting for peoples choice is open from 8:30pm Wednesday 9th to 12:00pm on Saturday the 12th February. Don't miss your chance to give John a helping hand by voting by phone, fax, sms or on the net as below.
You can vote in a number of different ways
Fax number: (02) 8333 2651
SMS - 1999 2220 (Insert 2 and send. You must have the facility)
Phone - 1902 55 22 77 (Listen, then when asked press 2)
Maximum 55c Inc GST.
Or by going to the New Inventors web site at ABC New Inventors
More information on TecEco and Eco-Cement can be found at the company web site at www.tececo.com
Dear Friends around the world
Thanks for all the congratulatory emails full of support and encouragement. They keep me going. I do however long for the day when talk that something should be done becomes talk about what has been done!
My name is John Harrison and I am the managing director of TecEco Pty. Ltd.,
a small company in far off Tasmania.
You sir are chairman of Shell - one of the most powerful companies on the planet.
You have encouraged me with your statements regarding climate change (See http://news.bbc.co.uk/1/hi/uk/3815151.stm).
There are reasons we should be talking to each other.
The need is obvious
The will is rising rapidly amongst the populations of the world
The means is lacking
My company can deliver the means to reduce CO2 in the air at an economic price with benefits to the oil industry.
Let me explain.
We are not likely to be able to reduce emissions quickly. The techno-process is powered by fossil fuels and people are not likely to give up their techno toys in a hurry. It is more likely that we start running out of fossil fuels first and price drives us out of burning liquid hydrocarbons. Coal will last much longer.
Carbon trading will help but an artificial price for CO2 would never be as good as a price supported by sound underlying economics.
Rationing as advocated by Meyer Hillman basically means one nation holding a gun over another. There are enough conflicts going on.
The answer is a holistic approach - reducing emissions at the same time as sequestering carbon. Both on a massive scale.
In your industry you should be aware of a fundamental law of economics espoused first by Pilzer and that is that technology defines what is or is not a resource. Only a paradigm shift in technology can deliver both emissions reduction and sequestration on a massive scale.
Attached is a process diagram to save the planet and make money at the same time.
The benefit for shell is a lot of bottled CO2 to geologically sequester, pushing up more oil to crack into hydrogen buying us time to develop more solar or indirect solar powered processes. The built environment is another good place to put the gas given the materials flows involved and the fact that the inhabitants will not notice. The magnesium carbonates nesquehonite and lansfordite are the main binders in our Eco-Cement and contain respectively 73 and 76% water and CO2, making them potentially very cheap.
Please take a look at the process diagram for a moment. Mineral sequestration using either forsterite or one of the serpentine group minerals is well advanced. The manufacture of Eco-Cement blocks, pavers, pervious pavement and a host of other components of the built environment is as far as I am concerned also well proven. The only component that has not yet been delivered in a workable form in the diagram is our kiln technology. We need money to develop it.
There is no doubt that magnesium oxide (magnesia, hydratable to brucite) is one of the best candidates for scrubbing CO2 out of the air. The process of manufacturing the material, hydrating and then carbonating it is favoured by thermodynamics and kinetics.
TecEco's kiln is, like Eco-Cement, a paradigm shift in technology because it will make it possible to manufacture magnesia and capture CO2 released at the same time. By combining calcining and grinding the process will also be around 30% more efficient than current processes. What's more, the calcination occurs readily at low temperatures and is therefore suitable for using solar, solar derived or waste energy.
We will achieve the ultimate challenge, making sustainability an economic process. Please consider helping us develop and install the technology on a massive scale as a money making venture for Shell under the Kyoto regime.
More information can be found on our web site. I look forward to further discussions
John Harrison B.Sc. B.Ec. FCPA
TecEco Pty. Ltd.
Materials are purchased and used for the volume they occupy providing a given set of properties.
I have for a long time thought that the use of the measure of CO2 per tonne of material is a nonsense so if you are using this term please think about the consequences especially in relation to the built environment which is 3D space.
Steel for example provides strength but at the cost of high thermal conductivity and weight, aluminium provides strength with a less weight. Steel is three times as heavy as aluminium so that there is actually 10.8 times greater embodied energy in steel as in aluminum per unit volume (and therefore more CO2 emissions on a volume basis).
Tececo cements provide strength but weigh less than Portland cement and because of their unique properties provide a more diverse set of properties. The embodied energy for the volume of cement produced is less.
The source of the energy would also make a difference - a lot of aluminum is
made in countries with cheap hydro-electric power such as Canada and I plan
to make TecEco cements using solar energy.
At the moment there is a high price for reactive magnesia relative to Portland cement. The process energies involved are however less for the volume of cement produced and debatably less for the mass or weight due to the fact that low temperature processes are inherently more efficient.
TecEco kiln technology combines grinding and calcining and captures CO2. More importantly the kiln is designed to operate using solar or solar derived energy as I have long argued that this is essential if we are to reverse damaging molecular flows that are the result of the techno-process such as too much CO2 going into the atmosphere.
Solar or solar derived energy is also potentially very cheap as there are no ongoing costs for fuel and using TecEco kiln technology to make reactive magnesia will bring the cost of Eco-Cements to below that of Portland cement.
Because of economy of scale issues In the short run TecEco are focusing on block manufacture using Tec-Cements as PC can be substituted on a 1:4 basis up to about 10% bringing the total input cost to below current levels. The blocks in the picture with their proud (still overweight) inventor contain around 30% less total binder than normal yet exceeded structural standards with ease. The strength reduced by the aspect ratio according to the Australian Standard AS/NZS 4456.4 for the eight (2001, standard structural) blocks tested was respectively 17.5, 16, 18.5, 23.5, 24, 16.5, 16.5 and 18.5 MPa averaging 19 MPa with an unbiased standard deviation of 3.37 MPa. The structural standard requires 12 MPa, non structural 8 MPa.
By David Moore, P.E., 1995
Retired Professional Engineer, Bureau of Reclamation
Assistant Professor, Central Texas College
Copyright 1993 David Moore, P.E.
(This article first appeared in "The Spillway" a newsletter of the US Dept. of the Interior, Bureau of Reclamation, Upper Colorado Region, February, 1993. The article is included with the kind permission of the Moore family. See www.romanconcrete.com for more information.)
Ancient Roman concrete has withstood the attack by elements for over 2,000 years. The basic construction techniques of the Romans must be better than those of modern practice as judged by comparing the products. Can we learn from the Romans in some way to improve our concrete?
Dusty ancient history books taught us that Roman concrete consisted of just three parts: a pasty, hydrate lime; pozzolan ash from a nearby volcano; and a few pieces of fist-sized rock. If these parts were mixed together in the manner of modern concrete and placed in a structure, the result certainly would not pass the test of the ages. The riddle plaguing the minds of our concrete specialists . . . how did those Romans around the time of Christ build such elaborate, ageless structures in concrete as seen on the skyline of Rome?
A most unusual Roman structure depicting their technical advancement is the Pantheon, a brick faced building that has withstood the ravages of weathering in near perfect condition, sitting magnificently in the business district of Rome. Perhaps its longevity is told by its purpose . . . to honor all gods. Above all, this building humbles the modern engineer not only in its artistic splendor, but also because there are no steel rods to counter the high tensile forces such as we need to hold modern concrete together. Describing this large circular building tells much of the intelligence of its builders; it was designed to contain a fictional ball, and is some 143 feet in diameter with a wall in the form of skirts dropping from its circumference. In the center of the dome is a 19-foot opening held in place by a bronze ring backed by a brick ring integrated into the concrete dome. This ingenious opening admitted sunlight to brighten the interior The slightly curved marble floor provided drainage and the complex notches in the walls and ceiling tell only a few features of its meticulous design.
Solving the riddle of ancient concrete consisted of two studies: one was understanding the chemistry, and the other was determining the placement of ancient concrete. To understand its chemical composition, we must go back in time much before Moses. People of the Middle East made walls for their fortifications and homes by pounding moist clay between forms, often called pise work. To protect the surfaces of the clay from erosion, the ancients discovered that a moist coating of thin, white, burnt limestone would chemically combine with the gases in the air to give a hard protecting shied. We can only guess that the event of discovering pseudo concrete occurred some 200 years before Christ when a lime coating was applied to a wall made of volcanic, pozzolanic ash near the town of Pozzuoli in Italy.
A chemical reaction took place between the chemicals in the wall of volcanic ash (silica and small amounts of alumina and iron oxide) and the layer of lime (calcium hydroxide) applied to the wall. Later they found that mixing a little volcanic ash in a fine powder with the moist lime made a thicker coat, but it also produced a durable product that could be submerged in water- something that the plaster product of wet lime and plain sand could not match.
To explain this chemical difference we must examine the atomic structure. Common plaster is made with wet lime and plain sand. This sand has a crystalline atomic structure whereby the silica is so condensed there are no atom holes in the molecular network to allow the calcium hydroxide molecule from the lime to enter and react. The opposite is true with the wet lime-pozzolan contact. The pozzolan has an amorphous silica atomic structure with many holes in the molecular network. Upon mixing the wet lime with the pozzolan, the calcium hydroxide enters the atomic holes to make a concrete gel that expands, bonding pieces of rock together. The fine powder condition of the pozzolan provides a large surface area to enhance chemical reaction. We find parts of the complex chemistry of the ancient concrete bonding gel matching the same chemical formula of modern concrete bonding gel. So the pozzolan-wet lime gel gave permanence to the ancient concrete.
Explaining the placement of ancient concrete solved the second part of the riddle. Unwittingly, research by the Bureau of Reclamation played a key role here. Chemistry alone will not make good concrete. People make good concrete, and the Bureau of Reclamation has claimed the fame of this expertise. Although a new concrete product called roller compacted concrete had been crudely developed, Reclamation's refinements made it an economical candidate for dam construction. In 1987, the Bureau of Reclamation's astute engineering force built the large Upper Stillwater Dam made of roller compacted concrete in eastern Utah. This concrete consisted of a mixture of 40 percent Portland cement and 60 percent fly ash, a byproduct of electric power plants. By coincidence, the fly ash contained the same amorphous silica compounds as the ash from explosive volcanoes. And the hydrated Portland cement released the calcium component recognized in the lime part of the ancient concrete formula.
When the Bureau of Reclamation mixed these two parts for their dam, a bonding gel was formed to tie inert rock pieces of the hatch together. The rocks were used as a strong filler material much in the same manner as is used in standard concrete practices. So we can easily relate the calcium hydroxide molecules from the Portland cement to that of the ancient wet lime, and the amorphous silica of the pozzolan fly ash to the amorphous silica of the volcanic pozzolan. Thus, we have established a reasonable relationship for the concrete components that make the gel for both modern and ancient concrete.
The similarity of the ingredients of modern and ancient concrete has been explained, but there is more. Studies of the placement process are very important in making durable concrete. The Bureau of Reclamation mixed their components (cement, ash, and rock) with as little water as possible to give a stiff, "no-slump" concrete; spread it in layers on the dam; and pounded it into place by large vibrating rollers to make a new class of concrete.
The ancients hand mixed their components (wet lime and volcanic ash) in a mortar box with very little water to give a nearly dry composition; carried it to the job site in baskets placing it over a previously prepared layer of rock pieces; and then proceeded to pound the mortar into the rock layer. Fortunately, we have proof. Vitruvius, the noted Roman architect (cir. 20 BC) mentioned this process in his history formulas for his concrete, plus the fact that special tamping tools were used to build a cistern wall. Is this important? Yes, close packing of the molecular structure by tamping reduced the need of excess water, which is a source of voids and weakness. But also close packing produces more bonding gel than might be normally expected. Again, we have a similarity in the ancient and roller compacted concrete practices, which is that of tightly compacting the materials in their placement.
We have learned that ancient concrete was a simple mixture of wet lime and pozzolan in specific ratios to match the desires of the Roman architect. We have also learned that the Romans followed a placement method of tamping their stiff mortar into the voids of a rock layer. And interestingly enough, the new concrete that has been developed by the Bureau of Reclamation follows closely that of the ancients. So we can readily assume that the new class of concrete in Upper Stillwater Dam will last . . .perhaps for 2.000 years like the ancient Roman concrete.