Eco-efficient cements:Potential economically viable solutions for a low CO2 Cement Based Materials industry

Karen Scrivener, EPFL, SwitzerlandVanderley John, USP, Brazil

Ellis Gartner, Imperial College, UK

Cement Based Materials: cannot be replaced by alternatives

0 2000 4000 6000 8000 10000 12000 14000 16000 18000

Cementitious

Wood

Ceramic

Iron

Lime

Asphalt

Glass

Aluminium

Copper

Materials production (Mt/year)

Cementitious materials make up 30-50%of everything we produce.

In the light of this,CO2 emissions of 5-10%

very good

Concrete is an environmentally friendly materialMaterial MJ/kg kgCO2/kg

Cement 4.6 0.83

Concrete 0.95 0.13Masonry 3.0 0.22

Wood 8.5 0.46

Wood: multilayer 15 0.81

Steel: Virgin 35 2.8

Steel: Recycled 9.5 0.43

Aluminium: virgin 218 11.46

Aluminium recycled

28.8 1.69

Glass fibre composites

100 8.1

Glass 15.7 0.85

ICE version 1.6aHammond G.P. and Jones C.I 2008 Proc Instn Civil Engineerswww.bath.ac.uk/mech-eng/sert/embodied/

Rel

ativ

e en

ergy

, CO

2

Given these low figures, local supply is keyTransport costs:1 kg by sea Australia to Europe = 0.5 kg CO2

Forecast growth

We need solutions for people in developing countries

0

2000

4000

6000

8000

2015 2025 2035 2045

Prod

uctio

n (M

t)

OECD

China

India

Other

11 10

54

32

8

22

2637

0%

20%

40%

60%

80%

100%

2015 2050

Contribution of cement to CO2 emissions

5

0.00

5.00

10.00

15.00

20.00

25.00

30.00

Countries ranked by CO2 emission from cement production

%overall CO2 from cement

World average

UNEP report

Download at

http://lmc.epfl.ch

“White Papers”: special issue of Cement and Concrete Research1. Alternative Cement Clinkers: Ellis GARTNER and SUI Tongbo2. Alkali Activated Binder: John PROVIS3. Calcined Clays as Supplementary Cementitious Materials: Karen SCRIVENER4. Vegetable ashes as Supplementary Cementitious Materials:

Fernando MARTIRENA and Jose Maria MONZO BALBUENA5. Engineered Fillers and Dispersants in Cementitious Materials:

Vanderley M JOHN, Bruno L DAMINELI, Marco QUATRONE, Rafael PILEGGI6. Admixtures and Sustainability:

Josephine CHEUNG, Lawrence ROBERTS, and Jiaping LIU7. Earth Concrete: Henri VAN DAMME and Hugo HOUBEN8. Education for Sustainable Use of Cement Based Materials:

Wolfram SCHMIDT, Mark ALEXANDER and Vanderley JOHN9. CO2 Reduction Potential of New Cement-Based Materials Technologies:

Sarah MILLER, Vanderley M JOHN, Sergio de Almeida PACCA, Arpad HORVATH

White Paper structure

Description of the technology, degree of development, scope of application robustness when used in different climates and by

people without formal training; Overview of durability; State of the development and research needs; Scalability potential, including raw material availability.; Investment and production costs in comparison with

Portland cement; CO2 mitigation potential; Barriers and incentives for introduction of the

technology; Research priorities to further develop the technology.

Use of Cementitious Materials

0.1

0.15

0.2

0.25

0.3

0.35

0.4

2002 2004 2006 2008 2010 2012 2014

Frac

tion

of C

emen

t use

d w

ith

Rein

forc

men

t (t/

t)

Global Brazil

China EU

USA

Proportion of cement used with reinforcing steel

BricklayingRenders

-200

0

200

400

600

800

1000

0 10 20 30 40 50 60 70

CO

2M

itiga

tion

Pote

ntia

l(M

t)

Market Share at 2050 (%)

Geopolymer + Calcined clay

BYF

CCSC

Calcined Clayand limestone

Fillers 30%

CO2 mitigation potential of different technologies

“New” solutions mitigation potential

-300

-100

100

300

500

700

0 5 10 15 20

CO

2 m

itiga

tion

Pote

ntia

l (M

t)

Market Share 2050 (%)

Geopolymer CC

BFY

CCSC

CCS/U Target

Alternative clinkers

13

How cement works:

Cement grain water hydrates

reaction with water increases solid volume, joins grains together

What is available on earth?

Na2OK2OFe2O3

MgOCaOSiO2

Al2O3

Too soluble

Too low mobility in alkaline solutio

The most useful

MgK

rest

Na

CaFe

Al

Si

O

Slagcementblend

SiO2

Al2O3CaO

Portland Cement

16

Hydraulic materials in CaO-SiO2-Al2O3 system

Calcium aluminate /calcium sulfo aluminate

BUT, what sources of minerals are there which contain Al2O3 >> SiO2 ?Bauxite – localised, under increasing demand for Aluminium production, EXPENSIVE(100-500€/tonne)

Also resource limited. All current bauxite production diverted to produce CSA would cover <15% of need

BYF: Belite Ye’elimite Ferrite cements

First hydrating phase in Ye’elimite, C4A3$ - calcium sulfo aluminate

Problem is expense of high alumina sources (bauxite)

Potential to reuse waste alumina materials (bauxite residue)

Maximum penetration of 10% assumes all present bauxite production used for BYF

17

Clinker compound: Chemical CO2 emissions, kg/tonne

Alite (C3S) 579Belite (C2S) 512Tricalcium Aluminate (C3A) 489Tetracalcium Alumino-Ferrite (C4AF, “Ferrite”) 362Quicklime (CaO) 786Wollastonite (CS) [a major component in Solidia clinkers]

379

Ye’elimite (C4A3$)[made with CaSO4 as sulphur source]

216

Periclase (MgO) [made from magnesium carbonate]

1100

Periclase (MgO) [made from basic magnesium silicate rocks]

0

Belite rich clinkers <10% reduction more than offset by slower kinetics

Good reduction potential

Much worse than calcium silicates

Portland based cement will continue to be dominant

Incredible economy of scalemarginal cost of clinker is as low as $20 per tonne!

Raw materials abundant nearly everywhere Easily manipuable open time Robust

Portland cement is amazingly robust

• Open time of several hours – easy to manipulate with admixtures• Hardened in matter of days

~10 h ~24 h~3 h

Heat evolution

“New” solutions mitigation potential

-300

-100

100

300

500

700

0 5 10 15 20

CO

2 m

itiga

tion

Pote

ntia

l (M

t)

Market Share 2050 (%)

Geopolymer CC

BFY

CCSC

CCS/U Target

Alkali Activated Materials (Geopolymers)

22

Alkali Activated Materials / Geopolymers

Most formulations used in practice contain slag(high calcium flyash also possible)

Globally 8% of slag compared to cement, almost all already used in blended cement of in concrete

Negligible potential for further CO2 reduction by diversion to AAMs Need for activator (CO2 intensive) could even increase global CO2

Formulations with calcined clay could have potential But as present these need high amounts of sodium silicate (CO2 intensive) Max penetration of 15% shown would require 40X increase in sodium silicate

production! Technical difficulties

Robustness Durability

Unlikely to be more than niche in some pre-cast operations.

23

“New” solutions mitigation potential

-300

-100

100

300

500

700

0 5 10 15 20

CO

2 m

itiga

tion

Pote

ntia

l (M

t)

Market Share 2050 (%)

Geopolymer CC

BFY

CCSC

CCS/U Target

“New” cements mitigation potential

-300

-100

100

300

500

700

0 5 10 15 20

CO

2 m

itiga

tion

Pote

ntia

l (M

t)

Market Share 2050 (%)

Geopolymer CC

BFY

CCSC

CCS/U Target

CCSC: Carbonating Calcium silicate cements

Wolastonite, CS clinker Lower CO2 emissions Hardens by carbonation Overall CO2 reduction ~ 60% “Solidia” technology

Limitations Thin elements, to get CO2 in No reinforcement Carbonation chamber CO2 source

26

Long term prospect: Carbonating Magnesia based cementsNot from Magnesium Carbonates – this has much

higher emissions than calcium silicate Portland cements

Magnesium silicates could be a source, but at present no process to do this economically at scale

Magnesium silicates are abundant but much more localised than limestone

27

Conclusions: new binders

Cost is higher than OPC, but lower than CCSMarket penetration more limitedBYF / CSA Carbonation hardening: Carbon Capture and Use AAC or Geopolymer

Calcined clay: new route production for sodium silicate

GBFS: Low CO2, almost no mitigation potential

-200

0

200

400

600

800

1000

0 10 20 30 40 50 60 70

CO

2M

itiga

tion

Pote

ntia

l(M

t)

Market Share at 2050 (%)

Geopolymer + Calcined clay

BYF

CCSC

Calcined Clayand limestone

Fillers 30%

CO2 mitigation potential of different technologies

Extending use of blended cements

Will be discussed later

30

-200

0

200

400

600

800

1000

0 10 20 30 40 50 60 70

CO

2M

itiga

tion

Pote

ntia

l(M

t)

Market Share at 2050 (%)

Fillers 30%

Extending use of SCMs:Calcined Clayand limestone(50%)

2 solutions have large potential to reduce CO2

MITIGATION POTENTIAL OF INDUSTRIALIZATION

Materials wastage

Materials wastage

Materials wastage

Industrialization reduces wastage rates Data from High-Rise building sites in Brazil

Coarse aggregate

s

Sand CementReady-

mixconcrete

Mat

eria

ls w

asta

ge ra

te

(%)

Efficiency of binder use (29 countries)

0

5

10

15

20

0 20 40 60 80 100

Bin

der I

nten

sity

(kg/

m³.M

Pa)

Compressive Strength (MPa)

250kg/m³

DAMINELI, et al . Measuring the eco-efficiency of cement use. Cement and Concrete Composites, 32, p. 555-562, 2010

Site mixing

Ready-mixed industrial

Bulk Market Share

Cement production isconcentrated in markets with high share of inefficient bagged cement

Sales of bagged cement in Europe already very low R² = 0.7233

0

20

40

60

80

100

0 20000 40000 60000 80000

Cem

ent i

n B

ulk

(%)

GDP per capita (USD)

1st Filler as cement replacement50% cement substitution

Arrowrock Dam – 1915, Boise River, IdahoPhoto: Gary O Grimm

DAVIS et al. ASTM STP99 1950

Max Limestone Filler in standards

1990

2007

2008

2012

?

2010

2015

2002

1992

0 5 10 15 20 25 30 35 40

Brasil

China

Canada

USA

Nova Zelândia

Austrália

Argentina

África do Sul

Europa

High filler, advanced performancewater & binder minimization technology

Good rheology min water

ParticleDispersion

MinimumBinder

Particle packing

Filler without dispersion:agglomeration may increase water demand

LEAP cement + filler

Dispersants are key enabling technology

Efficiency of binder use (29 countries)

0

5

10

15

20

0 20 40 60 80 100

Bin

der I

nten

sity

(kg/

m³.M

Pa)

Compressive Strength (MPa)

250kg/m³

DAMINELI, et all . Measuring the eco-efficiency of cement use. Cement and Concrete Composites, v.

Low-Binder concrete formulations(29 countries)

0

5

10

15

20

0 20 40 60 80 100

Bin

der I

nten

sity

(kg/

m³.M

Pa)

Compressive Strength (MPa)

250kg/m³

CBI/KTH - Sweden; USP – Brazil; U Darmastad, U Karlsrhue, VDZ - Germany

-200

0

200

400

600

800

1000

0 10 20 30 40 50 60 70

CO

2M

itiga

tion

Pote

ntia

l(M

t)

Market Share at 2050 (%)

Fillers 30%

Extending use of SCMs:Calcined Clayand limestone(50%)

2 solutions have large potential to reduce CO2

Conclusions: Portland clinker based Calcined Clay + Pozzolan and Filler Low cost Unlimited raw materials High filler: protection of steel may be a problem

Industrialization of cement use Low- cost New-design methods Mitigation potential probably ~CCS target

Can substitute CCS and exceed! Cheaper and simple to scale-up

Conclusions

Research, Development & Innovation investments Governmental Industry Education, standardization are challenges CCS is not the most promising mitigation

technology

vmjohn@usp.brkaren.scrivener@epfl.ch

THANK YOU!