An overview of Future Cements

1. An overview of Future Cements An overview of the alternative mineral binder systems including novel concrete technologies addressing practical supply chain and economic issues including energy www.tececo.com www.propubs.com

2. Why Future Cements?The Techno Process Primary Production Process Build, & Manufacture Use Dispose Underlying Molecular Flows Disposeor Waste Process,Build &Manufacture Use PrimaryProduction NOX & SOX Heavy Metals CO2etc. MethaneNOX & SOX Heavy MetalsCO2etc. Methane NOX & SOXHeavy MetalsCO2etc. NOX & SOX Heavy Metals CO2etc. Lifetime Energy Embodied & Process Energy Process Energy Embodied & Process Energy

3. Portland Cement ProductionPart of the Problem and/or Potential Solution? Source USGS: Cement Pages

4. Criteria for New Cements

5. Future Cement ContendersPC and Derivatives • http://www.tececo.com/files/spreadsheets/TecEcoCementLCA20Jan2011.xls • http://www.tececo.com/files/newsletters/Newsletter93.php

6. The Global Warming Problem Global Carbon FlowsAfter: David Schimel and Lisa Dilling, National Centre for Atmospheric Research 2003 The global CO2 budget is the balance of CO2 transfers to and from the atmosphere. The transfers shown below represent the CO2 budget after removing the large natural transfers (shown to the right) which are thought to have been nearly in balance before human influence. Woods Hole Carbon Equation (In billions of metric tonnes) From: Haughton, R., Understanding the Global Carbon Cycle. 2009, Woods Hole Institute at http://www.whrc.org/carbon/index.htm

7. Net Atmospheric Increase in Termsof Billions of Tonnes CO2 Using the Figures from Woods Hole on the Previous Slide Converting to tonnes CO2 in the same units by multiplying by 44.01/12.01, the ratio of the respective molecular weights. From the above the annual atmospheric increase of CO2 is in the order of 12 billion metric tonnes.

8. How Much Man Made Carbonateto Solve Global Warming? If a proportion of the built environment were man made carbonate, how much would we need to reverse global warming? MgO + H2O => Mg(OH)2 + CO2 + 2H2O => MgCO3.3H2O40.31 + 18(l) => 58.31 + 44.01(g) + 2 X 18(l) => 138.368 molar masses.44.01 parts by mass of CO2 ~= 138.368 parts by mass MgCO3.3H2O1 ~= 138.368/44.01= 3.14412 billion tonnes CO2 ~= 37.728 billion tonnes of nesquehonite or MgO + H2O => Mg(OH)2 + CO2 + 2H2O => MgCO340.31 + 18(l) => 58.31 + 44.01(g) + 2 X 18(l) => 84.32 molar masses.CO2 ~= MgCO344.01 parts by mass of CO2 ~= 84.32 parts by mass MgCO31 ~= 84.32/44.01= 1.915912 billion tonnes CO2 ~= 22.99 billion tonnes magnesite CaO + H2O => Ca(OH)2 + CO2 + 2H2O => CaCO356.08 + 18(l) => 74.08 + 44.01(g) + 2 X 18(l) => 100.09 molar masses.CO2 ~= CaCO344.01 parts by mass of CO2 ~= 100.09 parts by mass MgCO31 ~= 100.09/44.01= 2.27412 billion tonnes CO2 ~= 27.29 billion tonnes calcite (limestone)

9. Modified PC 50% Ternary PC Mixwith N-Mg Route Mg Carbonate Aggregate The addition of 6 - 10% MgO replacing PC in high substitution mixes accelerates setting. Source USGS: Cement Pages

10. Modified PC 50% Ternary Mix withN-Mg Route Mg Carbonate Aggregate • 25-30% improvement in strength • Fast first set • Better Rheology • Less shrinkage – less cracking • Less bleeding • Long term durability • Solve autogenous shrinkage?

11. Future Cement ContendersMg Group • http://www.tececo.com/files/spreadsheets/TecEcoCementLCA20Jan2011.xls

12. Magnesium Phosphate Cements • Chemical cements that rely on the precipitation of insoluble magnesium phosphate from a mix of magnesium oxide and a soluble phosphate. • Some of the oldest binders known (dung +MgO) • Potentially very green • if the magnesium oxide used is made with no releases or via the nesquehonite (N-Mg route) and • a way can be found to utilise waste phosphate from intensive agriculture and fisheries e.g. feedlots. (Thereby solving another environmental problem)

13. Sorel Type Cements and Derivatives Sorel Type Cements and Derivatives are all nano or mechano composites relying on a mix of ionic, co-valent and polar bonding. There are a very large number of permutations and combinations and thus a large number of patents

14. Magnesium Carbonate Cements • Magnesite (MgCO3) and the di, tri, and pentahydrates known as barringtonite (MgCO3·2H2O), nesquehonite (MgCO3·3H2O), and lansfordite (MgCO3·5H2O), respectively. • Some basic forms such as artinite (MgCO3·Mg(OH)2·3H2O),hydromagnestite (4MgCO3·Mg(OH)2·4H2O) and dypingite (4MgCO3· Mg(OH)2·5H2O) also occur as minerals. • We pointed out as early as 2001 that magnesium carbonates are ideal for sequestration as building materials mainly because a higher proportion of CO2 than with calcium can be bound and significant strength can be achieved. • The significant strength is a result of increased density through carbonation (high molar volume increases) and the microstructure developed by some forms.

15. Future Cement ContendersMg Group • http://www.tececo.com/files/spreadsheets/TecEcoCementLCA20Jan2011.xls

16. TecEco Eco-Cements (Tec-Kiln) Eco-Cements are blends of one or more hydraulic cements and relatively high proportions of reactive magnesia with or without pozzolans and supplementary cementitious additions. They will only carbonate in gas permeable substrates forming strong fibrous minerals. Water vapour and CO2 must be available for carbonation to ensue. Eco-Cements can be used in a wide range of products from foamed concretes to bricks, blocks and pavers, mortars renders, grouts and pervious concretes such as our own permeacocrete. Somewhere in the vicinity of the Pareto proportion (80%) of conventional concretes could be replaced by Eco-Cement. Left: Recent Eco-Cement blocks made, transported and erected in a week. Laying and Eco-Cement floor. Eco-Cement mortar & Eco-cement mud bricks. Right: Eco-Cement permeacocretes and foamed concretes

17. TecEco Eco-Cements (Tec-Kiln, N-Mg route) Scope for Reducing Energy Using Waste Heat? Initial weight loss below 100" consists almost entirely of water (1.3 molecules per molecule of nesquehonite). Between 100 and 1500C volatilization of further water is associated with a small loss of carbon dioxide (~3-5 %). From 1500C to 2500C, the residual water content varies between 0-6 and 0-2 molecules per molecule of MgC03. Above 3000C, loss of carbon dioxide becomes appreciable and is virtually complete by 4200C, leaving MgO with a small residual water content. Energy could be saved using a two stage calcination process using waste energy for the first stage. Nesquehonite courtesy of Vincenzo Ferrini, university of Rome. Dell, R. M. and S. W. Weller (1959). "The Thermal Decomposition of Nesquehonite MgCO3 3H20 And Magnesium Ammonium Carbonate MgCO3 (NH4)2CO3 4H2O." Trans Faraday Soc 55(10): 2203 - 2220.

18. Moleconomic Flows – N-Mg ProcessThe Nesquehonite Route The annual world production of HCl is about 20 million tons, most of which is captive (about 5 million tons on the merchant market). 

19. The Tec-Reactor HydroxideCarbonate Capture Cycle • The solubility of carbon dioxide gas in seawater • Increases as the temperature approached zero and • Is at a maxima around 4oC • This phenomenon is related to the chemical nature of CO2 and water and • Can be utilised in a carbonate – hydroxide slurry process to capture CO2 out of the air and release it for storage or use in a controlled manner

20. Gaia Engineering Portland CementManufacture CaO TecEcoTec-Kiln MgO Industrial CO2 Clays Brine, Seawater, Oil Process water, De Sal Waste Water etc . GBFS TecEcoCementManufacture N-Mg Process MgCO3.3H2O Fly ash Eco-Cements Tec-Cements NH4Cl or HCl FreshWater Buildingcomponents & aggregates Other wastes

21. The N-Mg Process HCl NH3 and a small amount of CO2 MgCO3.3H2O CO2 Mg rich water MgO Tec-Kiln Ammoniacal Mg rich water Mg(OH)2 H2O MgO Steam MgCO3.3H2O Filter NH4Cl and a small amount of NH4HCO3 Filter A Modified Solvay Process for Nesquehonite

22. Future Cement Contenders • http://www.tececo.com/files/spreadsheets/TecEcoCementLCA20Jan2011.xls • Quillin, K. and P. Nixon (2006). Environmentally Friendly MgO-based cements to support sustainable construction - Final report, British Research Establishment. • http://www.geopolymers.com.au/science/sustainability

23. CaO-Lime

24. Geopolymers

25. Other Contenders • Belite cements suffer from a slower setting rate which could be accelerated with more aluminates rather than alite. MgO works to some extent as well althougth as yet we have not done enough work • Sulfoaluminate type cements have a low energy requirement.

26. Barriers to Market - Patents Fierce competition whilst the world heats up reminds me of Nero. Perhaps a more co-operative approach is more appropriate. We face after all common supply chain, economic and technical issues. We should jointly be marketing to governments as new technologies are essential as the potential for emissions reduction and sequestration is enormous http://www.google.com/patents?id=hhYJAAAAEBAJ&printsec=abstract&zoom=4#v=onepage&q&f=false

27. Barriers to Market – Lack of Carbon Trading TecEco have been held up by unrelenting patent attacks, unfair competition from universities and a lack of carbon trading. There are still some easily overcome supply chain and economy of scale issues however we have invented our way through most of them.

28. The Concept of a Carbonate Built Environment 13th July 2002 – Fred Pearce in New Scientist about TecEco magnesium cement technology: “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. All we have to do is change the way we do things and do what a big old tree does – make our homes out of CO2