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

18/04/23 www.tececo.comwww.propubs.com 1

Why Future Cements?The Techno Process

Primary Production Process Build, & Manufacture Use Dispose

Underlying Molecular FlowsPrimary

Production

Methane NOX &

SOXHeavy Metals

CO2

etc.Embodied & Process

Energy

Process,Build

&Manufacture

NOX & SOX

Heavy Metals CO2

etc.

Embodied & Process

Energy

Use

NOX & SOX

Heavy Metals CO2

etc.

Lifetime Energy

Disposeor WasteMethane

NOX & SOX

Heavy Metals

CO2

etc.

Process Energy

Portland Cement ProductionPart of the Problem and/or Potential Solution?

Source USGS: Cement Pages

Assumptions - 50% non PC N-Mg mix and Substitution by Mg Carbonate AggregatePercentage by Weight of Cement in Concrete 15.00%Percentage by weight of MgO in cement 6%Percentage by weight CaO in cement 29%Proportion Cement Flyash and/or GBFS 50%1 tonne Portland Cement 0.864Tonnes CO2Proportion Concrete that is Aggregate 72.5%CO2 captured in 1 tonne aggregate 1.092Tonnes CO2CO2 captured in 1 tonne MgO (N-Mg route) 2.146Tonnes CO2CO2 captured in 1 tonne CaO (in PC) 0.785Tonnes CO2

Criteria for New Cements

Criteria Good BadEnergy Requirements and Chemical Releases, Reabsorption (Sequestration?)

Speed and Ease of Implementation

Barriers to Deployment

Cost/Benefit

Use of Wastes? or Allow Use of Wastes?

Performance

Engineering

Thermal

Architectural

Safety

Audience 1

Audience 2

Future Cement ContendersPC and Derivatives

1. http://www.tececo.com/files/spreadsheets/TecEcoCementLCA20Jan2011.xls2. http://www.tececo.com/files/newsletters/Newsletter93.php

The Global Warming Problem

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.

Global Carbon FlowsAfter: David Schimel and Lisa Dilling, National Centre for Atmospheric Research 2003

Atmospheric increase

= Emissions from fossil fuels

+ Net emissions from changes in land use

- Oceanic uptake

- Missing carbon sink

3.2 (±0.2)

6.3 (±0.4) 2.2 (±0.8) 2.4 (±0.7) 2.9 (±1.1)

From: Haughton, R., Understanding the Global Carbon Cycle. 2009, Woods Hole Institute at http://www.whrc.org/carbon/index.htm

Woods Hole Carbon Equation (In billions of metric tonnes)

Net Atmospheric Increase in Termsof Billions of Tonnes CO2

Atmospheric increase

= Emissions from fossil fuels

+ Net emissions from changes in land use

- Oceanic uptake

- Missing carbon sink

3.2 (±0.2) 6.3 (±0.4) 2.2 (±0.8) 2.4 (±0.7) 2.9 (±1.1)

Converting to tonnes CO2 in the same units by multiplying by 44.01/12.01, the ratio of the respective molecular weights.

Atmospheric increase

= Emissions from fossil fuels

+ Net emissions from changes in land use

- Oceanic uptake

- Missing carbon sink

11.72 (±0.2) 23.08 (±0.4) 8.016 (±0.8) 8.79 (±0.7) 10.62 (±1.1)

From the above the annual atmospheric increase of CO2 is in the order of 12 billion metric tonnes.

Using the Figures from Woods Hole on the Previous Slide

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 nesquehoniteorMgO + 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)

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

Assumptions - 50% non PC N-Mg mix and Substitution by Mg Carbonate AggregatePercentage by Weight of Cement in Concrete 15.00%Percentage by weight of MgO in cement 6%Percentage by weight CaO in cement 29%Proportion Cement Flyash and/or GBFS 50%1 tonne Portland Cement 0.864Tonnes CO2Proportion Concrete that is Aggregate 72.5%CO2 captured in 1 tonne aggregate 1.092Tonnes CO2CO2 captured in 1 tonne MgO (N-Mg route) 2.146Tonnes CO2CO2 captured in 1 tonne CaO (in PC) 0.785Tonnes CO2

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?

Criteria Good BadEnergy Requirements and Chemical Releases, Reabsorption (Sequestration?)

Use >50% replacements and still set like “normal” concrete!

Speed and Ease of Implementation Rapid adoption possible

Barriers to Deployment

Permissions and rewards systems see http://www.tececo.com/sustainability.permissions_rewards.php

Cost/Benefit Excellent until fly ash runs out!

Use of Wastes? or Allow Use of Wastes?Uses GBFS and fly ash and nanufactured nesquehonite based aggregate

Performance Engineering Excellent all round Thermal High thermal capacity Architectural ExcellentSafety No issuesAudience 1Audience 2

Future Cement ContendersMg Group

1. http://www.tececo.com/files/spreadsheets/TecEcoCementLCA20Jan2011.xls

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)

Criteria Good BadEnergy Requirements and Chemical Releases, Reabsorption (Sequestration?) The MgO used could be made without releases There is not much phosphate on the planetSpeed and Ease of Implementation Rapid adoption possible If barrier overcome (see below)

Barriers to Deployment

Permissions and rewards systems see http://www.tececo.com/sustainability.permissions_rewards.php. Must find a way to extract phosphate from organic pollution.

Cost/Benefit Economies of scale issue for MgO to overcome

Use of Wastes? or Allow Use of Wastes?With technology could use waste phosphate reducing water pollution

Performance Engineering Excellent all round Thermal High thermal capacity ArchitecturalSafety No issuesAudience 1Audience 2

Sorel Type Cements and DerivativesSorel 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

Criteria Good BadEnergy Requirements and Chemical Releases, Reabsorption (Sequestration?) The MgO used could be made without releasesSpeed and Ease of Implementation More could be used If barrier overcome (see below) Barriers to Deployment Not waterproof even with modification.Cost/Benefit Economies of scale issue for MgO to overcomeUse of Wastes? or Allow Use of Wastes? Not waterproofPerformance Engineering Excellent except Not waterpoof, salt affect metals Thermal High thermal capacity ArchitecturalSafety No issuesAudience 1Audience 2

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.

Future Cement ContendersMg Group

1. http://www.tececo.com/files/spreadsheets/TecEcoCementLCA20Jan2011.xls

TecEco Eco-Cements (Tec-Kiln)

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

Criteria Good BadEnergy Requirements and Chemical Releases, Reabsorption (Sequestration?)

The MgO used could be made without releases and using the N-Mg route

Speed and Ease of ImplementationEasily implemented as no carbonation rooms etc reqd.

Permissions and rewards systems see http://www.tececo.com/sustainability.permissions_rewards.php.

Barriers to Deployment We need carbon trading!Cost/Benefit Economies of scale issue for MgO to overcomeUse of Wastes? or Allow Use of Wastes? A vast array of wastes can be incorporatedPerformance Engineering Excellent Need to be handled gently in the first few days Thermal Engineered thermal capacity and conductivity. ArchitecturalSafetyAudience 1Audience 2

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.

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.

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.

Nesquehonite courtesy of Vincenzo Ferrini, university of Rome.

Criteria Good BadEnergy Requirements and Chemical Releases, Reabsorption (Sequestration?) The total process uses two

Speed and Ease of ImplementationEasily implemented as no carbonation rooms etc reqd.

Permissions and rewards systems see http://www.tececo.com/sustainability.permissions_rewards.php.

Barriers to Deployment We need carbon trading!Cost/Benefit Economies of scale issue for MgO to overcomeUse of Wastes? or Allow Use of Wastes? A vast array of wastes can be incorporatedPerformance Engineering Excellent Need to be handled gently in the first few days Thermal Engineered thermal capacity and conductivity. ArchitecturalSafetyAudience 1Audience 2

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).

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

Gaia Engineering

MgCO3.3H2

ON-Mg

Process

NH4Cl or HCl

Industrial CO2 MgOTecEcoTec-Kiln

Eco-Cements

Buildingcomponents & aggregates

TecEcoCementManufacture

CaO

Clays

Portland CementManufacture

Brine, Seawater, Oil Process water, De Sal Waste Water etc .

Tec-Cements

Other wastes

FreshWater

GBFS

Fly ash

The N-Mg Process

Tec-Kiln

NH3 and a small amount of CO2

MgCO3.3H2O

MgO

MgO Mg(OH)2

CO2

H2O

Steam

NH4Cl and a small amount of NH4HCO3FilterFilter

Mg rich waterAm

mon

iaca

l Mg

rich

wat

er

MgCO3.3H2O

HCl

A Modified Solvay Process for Nesquehonite

Future Cement Contenders

1. http://www.tececo.com/files/spreadsheets/TecEcoCementLCA20Jan2011.xls3. Quillin, K. and P. Nixon (2006). Environmentally Friendly MgO-based cements to support sustainable construction - Final report, British Research Establishment.4. http://www.geopolymers.com.au/science/sustainability

CaO-Lime

Criteria Good BadEnergy Requirements and Chemical Releases, Reabsorption (Sequestration?) The CaO used could be made without

Speed and Ease of ImplementationEasily implemented as no carbonation rooms etc reqd.

Permissions and rewards systems see http://www.tececo.com/sustainability.permissions_rewards.php.

Barriers to Deployment We need carbon trading!Cost/BenefitUse of Wastes? or Allow Use of Wastes?Performance Engineering Good Thermal Engineered thermal capacity and conductivity. ArchitecturalSafety An irritating dustAudience 1Audience 2

Geopolymers

Criteria Good BadEnergy Requirements and Chemical Releases, Reabsorption (Sequestration?) Low provided we do not run out of fly ash

Speed and Ease of Implementation Process issues to be overcome

Permissions and rewards systems see http://www.tececo.com/sustainability.permissions_rewards.php.

Barriers to Deployment We need carbon trading!Cost/BenefitUse of Wastes? or Allow Use of Wastes?Performance Engineering Good but inconsistent Thermal Engineered thermal capacity and conductivity. ArchitecturalSafety Caustic liquorsAudience 1Audience 2

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.

Barriers to Market - Patents

http://www.google.com/patents?id=hhYJAAAAEBAJ&printsec=abstract&zoom=4#v=onepage&q&f=false

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

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.

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