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Keeping you informed about the TecEco Cement and Tec-Kiln projects. Issue 45, 16th March 2005
Kyoto now has the force of law and the reality is that 90% of our trade is with members of the treaty so it will effect us. We are involved.
Having said this it is important to remember that the objective is to get CO2 out of the air. To achieve this we really need to support what is an artificial price for carbon introduced by the treaty with a real underlying and hopefully one day dominating value.
We have to change the technical paradigm. Let me explain....
James Watt invented the steam engine and this used coal. Somebody else came along and said this black stuff is better because you can carry it about in a barrel. A few thousand inventions later and you have the well developed techo-process that now dominates our lives, our landscape and unfortunately our planet. This was a technical revolution of huge proportions.
Underlying the flow of all the materials that are involved are molecular flows in the global commons that are damaging to everything that lives. To mention but a few; heavy metals, CFC's and of course CO2 in the air. We are choking and poisoning ourselves - slowly. It's a bit like the old agar dish experiment from biology at school - remember how it works? You put a spec of bacteria in the middle of a food supply loaded in agar jelly and behold - the bacteria grows in a ring to the edge of the dish dying in the middle as the poisons in its world (the dish) kill it. There is no escape.
How can we avoid this fate? Fortunately the world is a big place and there are externals not present in the agar dish. Winds, tides and currents circulate nutrients like oxygen, microscopic food in the sea and take a way wastes. We used to live in a balanced ecological system where supply and demand were as in a stable economy balanced. We are alive because in natural systems that are in equilibrium there is no waste, no poison. Everything that is produced naturally is used naturally. That is until we came along with our machines and threw the whole lot of balance.
Not that I don't love my computer, my fridge, my car and so on - I admit that I do even though I try and ride my bike to work as much as I can. The trouble is that more than 500 million other people also love their cars. According to the Worldwatch Institute "In 2002, the world's passenger car fleet hit 531 million. A quarter of these cars were in the United States, a country with just five percent of the world's population, and a long known love affair for the automobile. The average car in the US travels 10 percent more each year than a car in the United Kingdom, about 50 percent more than one in Germany, and almost 200 percent more than a car in Japan." All these cars along with the airplanes, power stations and so on use fossil fuels and are upsetting our global carbon balance. Let's face it we have used up over half of the last few billion years worth of carbon stored by nature in the form of petroleum, and a somewhat lower proportion of the total coal.
How can we turn this juggernaut of such immense proportions around? I guess the point I am trying to make is that we have no choice but to change the technical paradigms. Part of this is learning how to use the flux of energy coming from the sun and from geo sources which is of immense proportions and everywhere but hard to capture. I once read that fossil fuel energy was only two millionths or was it billionths of the total flux. Can anybody email me with more authoritative numbers at john.harrison at tececo.com. Please replace at in our email address above with @, then write out the address with no spaces between the characters. (Our email address is released in this non-standard format, in order to foil the harvesting software used by spammers to capture the e-mail addresses of their victims.)
Unfortunately, even if we shut down all our power stations, garage all our cars and ground our planes global warming is inevitable - it will take hundreds of years to remove all the CO2 we have put in the air.
We have to find ways to get CO2 out of the air. These ways will not be effective unless everybody everywhere is using them so they have to be economic. They have to produce real tangible benefits that satisfy human survival instincts because human beings can never be expected to do anything just because it is the right thing to do. That is the responsibility of governments. Unfortunately however governments are only elected for a few years and the people involved are driven not so much by statesmanship but by the need to keep their jobs!
If the Australian and US governments are waiting for a technical revolution the size of the one started by James Watt then they had better stop their procrastination and talk to me because TecEco have the solution. Its simple really. I didn't even come up with the idea. I got it from nature. We must find uses for carbon dioxide. In nature the gas is used to create the homes of the vast proportion of plants and animals. We have to do the same. We have to find ways of incorporating carbon into our built environment and that is exactly what Eco-Cements do.
Using TecEco Eco-Cement and Tec-Kiln technologies we can change global carbon flows as in the diagram below.
By using carbon dioxide to build our homes just like shellfish and trees alike we can make a start. To get to the approximate rate of 15 billion tonnes per annum required to reverse global warming we will also have to, for a while at least until we are weaned of the fossil fuel habit, think of a few other ways of sequestering the gas. As yet it is not economic to shoot it into outer space so we will have to bury (geologically sequester) it like the rest of the rubbish we have buried for so many years. Fortunately the earth provides strata that held oil and natural gas for billions of years and will also most likely safely store carbon dioxide. Once in the ground, in most strata it will slowly be neutralised by alkaline rocks.
To scrub CO2 out of the air we need a way to do it. Some sort of artificial photosynthetic or mineralisation (as in shellfish) process is required. This way is likely to be a chemical reaction rather than a physical or mechanical process as the latter would be less efficient. Magnesium oxide-hydroxide systems are favoured because magnesium has a low molecular weight, bonding with a significant amount of CO2 . What's more driving the magnesium thermodynamic cycle around and around does not take huge amounts of energy and can generally occur at low temperatures. Non fossil fuel energy can be used.
The important step is the carbonation of magnesium hydroxide (Brucite) slurries. To do this however we needs lots of magnesium oxide and water. If we want to solve the problem the only way to make magnesium oxide is using sustainable non fossil fuel energy. The TecEco Tec-Kiln technology will provide this paradigm.
Some scientists think that we have a ten year window to turn global warming around. Even if they are all wrong it makes sense to move towards sustainability because living more sustainably in the long run involves spending less on resources like fuel and materials. Our wastes become our resources and our energy will come freely from the sun.
It is essential therefore that the funds required to develop the TecEco Cement and Tec-Kiln technology is forthcoming soon and at TecEco we think this is very much the role of governments.
Maybe then we could experience the security of moving into a low carbon future.
The concrete industry is in a terrific position to make money now carbon trading is a reality and at the same time become much more sustainable. I don't mean by burning tyres or tweaking the bearings on motors. I mean a fundamental improvement in sustainability. Let me explain.
First I must stress that the industry need to realise that they are really in the glue business. Organic binders are going out of favour because many such as urea and phenol formaldehyde have been linked to cancer. Pure mineral binders are much safer. Note however as there have also been some warnings about plasticisers and various other organic additives to concrete. It follows that if you could get to the end result without them is would be better.
The industry also need to become less polarised. There are a big range of mineral binders as one glance at sedimentary rocks should teach us and many have specific advantages. The concrete industry has been fixated on Portland cement because of the quirks of history and the fact that it is, relative to what has been previously been available, a good binder (well almost anyway). Industry managers need to understand that what is gray is not necessarily great and all they make will not be what goes out the gate in years to come.
How can I be so blasphemous! The reason is that there are strong drivers for change. These are robotics , the need to utilise wastes of all kinds and to reduce emissions. If we are to house the world more cheaply and effectively, remembering there are many who still do not have a proper home, then we are going to have to use what is available and cheap locally and wastes are usually cheap and we are also going to have to build very quickly and cheaply. In some countries labour will be cheap but in others robotics will be required to achieve these goals.
In this new paradigm buildings like the new Eureka building in Melbourne, Australia would go up with a central structural core but all around would be built with robots squeezing out a cementitious composite with a consistency a bit like toothpaste that will be smoothed off with little robo paddles. This technique is being developed by many people all over the world and I suspect the most advanced is Behrokh Khoshnevis at the University of Southern California. Think for a moment about the requirements for this "toothpaste" like composite. Some will need to be structural, some insulating, some sound proofing, some opaque.
Cementitious composites can in fact deliver a vast array of properties depending on their composition, aggregates and fillers. This leads me to the next point. If we want a more sustainable product wastes will need to be incorporated. What is more many wastes can impart the properties we are looking for in composites. What an opportunity! The global production of cement for 2005 will be around two billion tonnes and this means that we are pouring roughly 15 billion tonnes of concrete, more than two tonnes per person on the planet. This is the largest material flow by far and the obvious place to put wastes.
Toxic and hazardous waste technology and concrete technology will have to merge because the fact is the standards on risks associated with using wastes and the pressures to do so are both rising rapidly. Even now it no longer makes sense to just encapsulate waste materials in a concrete and bury them. They have to be so safe that we may as well make useful product out of them.
To sort wastes for their chemical composition at the tip face they first have to be disassembled and this is usually done with some sort of shredder. The problem is that most of us cannot identify them and robots that could do this quickly (especially if they were encoded with intelligence) are expensive.
Recycling for chemical composition is expensive in some areas, particularly away from big cites because of the cost of freight so why not recycle for physical property? That way plastics generally for example could compose a wastes stream instead of having to sort on the basis of composition - polycarbonate, polyethylene, styrene and so on (Can you tell the difference?). As a cheaper and possibly more affective alternative in country areas many of these wastes could be used for their physical properties imparted to the composites needed for construction, especially construction with robots. For example plastics generally are light in weight, have tensile strength and low conductance. Wood fibre if wasted on a tip is either burned (producing carbon dioxide) or anaerobicly decomposed releasing methane, which is worse.
If we are going to use all these wastes to make composites with a Bingham plastic quality that can be squeezed out like toothpaste we are going to have to work on reducing the reactivity of concrete as well as improve the rheology.
We can do a lot with chemicals but I worry about this. Most aromatics smell at about 3 or 4 parts per million or more in the air (yes our noses are that sensitive - think of the poor dogs and other animals that have a much stronger sense of smell!). If you can smell them you are breathing them. Ever wondered why so many of us are dying of cancer? I think a lot of the reason is the unnatural chemicals we imbibe. Modern plasticisers, air entraining agents, retarders etc. do not exist as molecules in nature, and being organic, tend to release volatile organic compounds (VOC's).
Portland cement concretes retain pore water and are alkaline in the long term. These properties are related because together they mean that the matrix inside the material is reactive. Tried picking up a lump of pure caustic soda? No problem as long as your fingers are dry. Then try wetting them first. Reactions generally occur much more readily in an aqueous medium than by diffusion and concretes retain a lot of water because we generally add twice as much as is actually needed for hydration reactions. Adding water also reduces the voids paste ratio reducing strength (Duff Abrams law) and the alkalinity during the early plastic stages with the result that silicification reactions are less effective.
There is another problem with Portland cement concretes as they are today. True, they have very low embodied energies relative to other building materials as in the graphic below.
The problem is the chemical release of CO2 during the manufacture of cement.
Consider the reactions involved.
CaCO3 => CaO + CO2 (gas); DeltaH = 178.77 kJ.mol-1, DeltaG = 130.98 kJ.mol-1
CaO + clay => clinker products (exothermic)
Now as you might expect the amount of CO2 released varies depending on the authority and assumptions made but generally a release of 1 tonne per tonne is accepted as reasonable. We have to work on capturing this chemically released carbon dioxide during the manufacture of cement and Kyoto may just make doing so economic.
There is something else happening. The oil industry want carbon dioxide - lots of it - delivered in tankers and ships to pump underground to push more oil up. Now much as I am against burning oil, putting CO2 underground is strata that managed to capture and hold oil for billions of years will probably work.
People in the industry need to think outside the square, to think about what TecEco are saying. Our technology will make concretes more sustainable and as in the long run sustainable and profit are actually the same direction there is nothing to fear from them!
The modifications to Portland cement proposed by TecEco will reduce the pH of concretes in the long run and because the hydration of magnesia consumes moisture, they will also be drier. For both these reasons they will be less reactive and the fact that brucite sticks well means that composites made with the modifications to PC binders suggested by us will be able to host a much wider range of wastes.
To really make concretes sustainable it will be necessary to make them using a more sustainable process and TecEco have designed a Tec-Kiln that combines calcining and grinding in the same vessel and can use non fossil fuel energy.
Instead of thinking about the ingredient - cement - we need to think from the market backwards. The industry would be very surprised if they actually did some market research to see what people really wanted in a binder. The problem is that they have never asked the question. Only by de-focusing from standard GP will a wider range of purchasing behaviors be satisfied and at the same time will the material evolve to be more sustainable by utilising a wider range of wastes.
For example the industry need to consider the implications of putting so much specific heat into cities. Ever walked up a pebbly beach after swimming on a warm sunny day? It's not easy because the rocks, which have high specific heat nearly burn your feet off. The use of permeable low fines concrete (TecEco permecocrete) would allow the ground to breathe, aquifers to replenish, makes roads safer and cleanse run off water which requires less infrastructure to transport it to the sea.
Concretes can be much greener and TecEco technology will allow the industry to make a painless transition towards sustainability by allowing us to tweak the material to respond to the drivers of robotics and the need to reduce net emissions and utilise waste.
On Tuesday and Wednesday the 15th and 16th of March 2005 I attended the Victorian Sustainability Conference and was the last speaker. As a result of my attendance I am concerned that the sustainability discussion is getting seriously off track.
There was a lot of talk about water and salinity. We heard policy makers and empire heads telling us what a great job they were doing, engineers telling us the solution was in more pipes, dams etc. yet there was no-one (except me) who attempted to get to the root of the problem and suggest strategies to alleviate it.
I enunciated the principles of biomimicry and suggested that in everything it should be considered.
The problem of salinity and water shortages is a complex one. Water is a mercurious asset that easily slips away. Engineers have for years compounded this problem by building streets, drains culverts and pipes to quickly take it away and farmers have been equally as guilty as they have denuded our soils of carbon in the form of humus which holds the water so it can do some good.
As a result of these bad practices water today takes much less time to return to the sea after rain both in the country and in cities. It does not replenish and freshen aquifers and we remove trees allowing the un replenished saline aquifers to rise bringing salt and poisoning the land.
We must return carbon in the form of a dry compost from bio waste and possibly sewerage to the soils and perhaps we could use empty trains returning to the countryside to carry the stuff. We must reconsider how we build streets and the associated drains. I mentioned to one chief engineer of a council the value of pervious pavements for in situ and dispersed treatment of run off water and I don't think he even understood what I was talking about.
Future editions of the TecEco Times will contain articles on water and the problem of salinity that will hopefully go to root of the problem.