developments needed in the production …webpages.mcgill.ca/staff/group3/aboyd1/web/conferences/amw...

DEVELOPMENTS NEEDED IN THE PRODUCTION AND USE OF CEMENT FOR LARGE REDUCTIONS IN

CO2 EMISSIONS BY 2050

DUNCAN HERFORT

Corresponds to stabilization of CO2 concentrations at c. 500 ppm and temperature increase of 2.4°C, and acidification of ocean above solubility product for aragonite.

From the IEA: “Four approaches can be applied to increase the energy efficiency and reduce CO2 emissions in the cement industry:

(1) increase the process energy efficiency, (2) use coal fuel substitutes,(3) capture and store CO2

(4) develop new cement types that reduce the use of cement clinker.”

MRS BULLETIN • VOLUME 33 • APRIL 2008 • www.mrs.org/bulletin • Harnessing Materials for Energy

2500 Mt

5000 Mt

At 0.81 tCO2 /t cement= 2000 Mt CO2 emission

Increasing to 4000 Mt

0

1

2

3

4

2008 2050

Glo

ba

l C

O2 e

mis

sio

n f

rom

ce

me

nt

pro

du

cti

on

10

9 t

on

ne

pa

improved kiln efficiency,

biofuel,n.gas where practicable

40% SMC for same concrete

performance

1/3 of RM CO2 recarbonated

1/4 of CO2 emissions stored

and captured

Serie1

Improved kiln efficiency, use of bio fuels & natural gas (0.93 109 t CO2)

40% SCM for same concrete performance (0.88 109 t CO2)

1/5 of RM CO2 recarbonated(0.34 109 t CO2)

2/5 of CO2 emissions captured and stored (0.83 109 t CO2)

Emissions must

effectively be

reduced from a

business as usual

scenario of 4 Gt to 1 Gt

CO2 EMISSIONS FROM CLINKER PRODUCTION

SCMS

CONCRETE CARBONATION

CARBON CAPTURE & STORAGE

ALKALI ACTIVATED ALUMINO SILICATES

CO2 EMISSIONS FROM CLINKER PRODCUTION

•RAW MATERIALS

•KILN EFFICIENCY

•LOW CARBON FUELS

SCMS




raw materials

C2S

C

S

C3S

C3S2

CS

CAC3A C12A7 CA2 CA6 A

A3S2

C2AS

CAS2

Argillaceous

Qz rich sand

Portland cement clinker

Limestone

C2S

C

S

C3S

C3S2

CS


A3S2

C2AS

CAS2

Argillaceous

Qz rich sand

Belite rich Portland cement clinker

Limestone

belite clinker

RM CO2 emissions reduced by about 10%.

C2S

C

S

C3S

C3S2

CS


A3S2

C2AS

CAS2

Argillaceous

Qz rich sand

Di and chainsilicates

Limestone

Further reductions in the Ca content form SiO2-saturated silicates which are non-hydraulic unless they are quenched to form a glass.

C2S

C

S

C3S

C3S2

CS


A3S2

C2AS

CAS2

Argillaceous

Qz rich sand


Limestone

Anorthosites

Anorthosite

C2S

C

S

C3S

C3S2

CS


A3S2

C2AS

CAS2

Argillaceous RMs

Quartz rich sand


BFS

Class C PFA

Limestone

BFS and Class C fly ash

LOW CARBON FUELS AND KILN EFFICIENCY

LOW CARBON FUELS AND KILN EFFICIENCY

CO2 emissions from FD and RM fuels as

function of heat consumption

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

600 800 1000 1200 1400 1600 1800 2000

heat consumption, kcal/kg

t C

O2 e

mis

sio

n /

t c

lin

ke

r

0.2

8

0.3

4

0.5

3 0

.80

0.5

3

Eff

icie

nt

dry

Euro

pe

an A

ve

rag

e

Eff

icie

nt

we

t

Inefficient wet

* *coalCO2 emissions from clinker production as a function of kiln efficiency

Coal R

aw

mate

rials

3 4 5 6 7

0.4

2

Glo

ba

l A

ve

rag

e

Heat consumption, GJ/t clinker

100 kWh/t cement = 0.1 t CO2

Energy Consumption - 2006 -(Average CEMBUREAU)

Alternative Fuels *

15.4%

HVFO

0,9%

Gas

0,9%

Fuel Oil

2,2%

Lignite/Shale/Schiste

7,9%

Coal & Petcoke

12,8%

Petcoke

39,1%

Coal

20,8%

© CEMBUREAU EL 5 March 2008

Total consumption

TJ= 821 409

*six countries

consumed between

40% & 90% of

alternative fuels

Global average of5% AF

Alternative fuels used in cement kilns - 2006-(Average CEMBUREAU)

0,0

2,0

4,0

6,0

8,0

10,0

12,0

14,0

16,0

18,0

20,0

Wood, p

aper

, car

dboard

Textil

es P

last

ics

RD

FR

ubber/T

yres

Indust

rial s

ludges

Munic

ipal

Sew

age

sludges

Anim

al m

eal,

fats

Coal

/Car

bon Was

te

Agric

ultura

l was

te

Solid a

ltern

ativ

e fu

els

(impre

gnated

saw

dust

)

Solven

ts a

nd rela

ted w

aste

Oil

and o

ily w

aste

Oth

ers

Wood, paper, cardboard

Textiles

Plastics

%

© CEMBUREAU EL 5 June 2008

RDF with typical

biomass content of35%

Used tires with typical

biomass content of 25%

Alternative fuels used in cement kilns - 2006-(Average CEMBUREAU)

0,0

2,0

4,0

6,0

8,0

10,0

12,0

14,0

16,0

18,0

20,0

Wood, p

aper

, car

dboard

Textil

es P

last

ics

RD

FR

ubber/T

yres

Indust

rial s

ludges

Munic

ipal

Sew

age

sludges

Anim

al m

eal,

fats

Coal

/Car

bon Was

te

Agric

ultura

l was

te

Solid a

ltern

ativ

e fu

els

(impre

gnated

saw

dust

)

Solven

ts a

nd rela

ted w

aste

Oil

and o

ily w

aste

Oth

ers

Wood, paper, cardboard

Textiles

Plastics

%

© CEMBUREAU EL 5 June 2008

In all 34% of AFs can beclassified as biomass

= 5% of total fuel



0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

600 800 1000 1200 1400 1600 1800 2000


t C

O2 e

mis

sio

n /

t c

lin

ke

r

0.2

8

0.3

4

0.5

3 0

.80

0.5

3

Eff

icie

nt

dry

Eu

rop

ean

Ave

rag

e

Eff

icie

nt

we

t

Inefficient wet


Coal R

aw

mate

rials

3 4 5 6 7

0.4

2

Glo

ba

l A

ve

rag

e




0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

600 800 1000 1200 1400 1600 1800 2000


t C

O2 e

mis

sio

n /

t c

lin

ke

r

0.2

0

0.5

3

Eff

icie

nt

dry

Eu

rop

ean

Ave

rag

e

Eff

icie

nt

we

t

Inefficient wet


Coal R

aw

mate

rials

3 4 5 6 7

Glo

ba

l A

ve

rag

e


20/20 biomass NG scenario

FD CO2 emission reduced to 0.20 t/t clinker

0

1

2

3

4

2008 2050

Glo

ba

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O2 e

mis

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n f

rom

ce

me

nt

pro

du

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10

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performance



and captured

Serie1


0

1

2

3

4

2008 2050

Glo

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O2 e

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performance



and captured

Serie1


This will happen anyway if an effective C&T system is in place

From an R&D perspective better understanding of the role

played by minor and trace elements is needed, including P2O5, leaching of heavy metals etc.

CO2 EMISSIONS FROM CLINKER

PRODCUTION

•RAW MATERIALS

•KILN EFFICIENCY

•LOW CARBON FUELS

SCMS




0 100 200 300 400 500 600

Cement

Fly ash

Blast furnace slag

Natural pozzolana

Burnt shale

Silica fume

Rice husk ash

Metakaolin

Mill. tons/year

Used in cement

Reserve

x

2003 figures

Availability of supplementary cementitious materials

IEA production data

published 2008:

Cement 2500 tpa

Fly ash 300 tpa

BF slag 220 tpa

i.e. max 20% of cement

C0.8SHy

C1.7SHx

C3A.CS.H12

C3A.CC.H12

C3A.3CS.H32

CH

C3A

70% GBFS

35% basaltic pozzolan

25% granitic pozzolan

25% calcined clay or PFA

Portland cement

stratlingite

silica gel

gibsite

20% Silica fume

C-S-Hss

clays

pozzolans

CEM I 32%

CEM II L 23%

Others 28%

CEM II M 17%

0

20

40

60

80

100

120

140

unspecified 32,5 42,5 52,5

strength class

millio

n t

on

ne

sCEM ICEM III,IV,V & II without limestoneCEM IIMCEM II L

CaSO4

monosulfate

Monocarbonate

ettringite

gypsum+ CSH + CH + FH3

+ pore solution

Hemicarbonate

Ms-ss

thaumasite

C4AH13

C3A

Reduced

porosity

Increased

porosity

CaCO3

calcite

-15

-10

-5

0

5

10

15

0 2 4 6 8 10 12 14 16 18 20 22

amount of CaCO3 added [wt.-%]

rela

tive c

han

ge o

f p

oro

sit

y a

nd

co

mp

ressiv

e s

tren

gth

[%

]

decrease

increase

compressive strength measured

total porosity calculated

Very good correlation between predicted changes of relative

porosity and measured compressive strength

Correlation: Porosity – Compressive Strength (exp. Data by D. Herfort, Aalborg cement)

-15

-10

-5

0

5

10

15

0 2 4 6 8 10 12 14 16 18 20 22

amount of CaCO3 added [wt.-%]

rela

tive c

han

ge o

f p

oro

sit

y a

nd

co

mp

ressiv

e s

tren

gth

[%

]

decrease

increase

compressive strength measured

total porosity calculated

Very good correlation between predicted changes of relative

porosity and measured compressive strength

C0.8SHy

C1.7SHx

C3A.CS.H12

C3A.CC.H12

C3A.3CS.H32

CH

C3A

70% GBFS




Portland cement

stratlingite

silica gel

gibsite

C-S-Hss

20% Silica fume clays

pozzolans

0

1

2

3

4

2008 2050

Glo

ba

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O2 e

mis

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rom

ce

me

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pro

du

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10

9 t

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performance



and captured

Serie1


40% clinker replacement for same concrete performance (0.88 109 t CO2)

0

1

2

3

4

2008 2050

Glo

ba

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O2 e

mis

sio

n f

rom

ce

me

nt

pro

du

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10

9 t

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performance



and captured

Serie1


40% clinker replacement for same concrete performance (0.88 109 t CO2)

This won’t happen on its own.

The mineralogical systems have to be developed to maximize

the use of SCMs for fit for purpose concrete performance.


PRODCUTION

•RAW MATERIALS

•KILN EFFICIENCY

•LOW CARBON FUELS

SCMS




Actual recycled

aggregate, stockpiled

1 year

0

1

2

3

4

2008 2050

Glo

ba

l C

O2 e

mis

sio

n f

rom

ce

me

nt

pro

du

cti

on

10

9 t

on

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performance



and captured

Serie1





PRODCUTION

•RAW MATERIALS

•KILN EFFICIENCY

•LOW CARBON FUELS

SCMS




CARBON CAPTURE AND STORAGE

POST COMBUSTION

Cement kiln

Air

Fuel

Clinker Raw materials

Residual exhaust gas

CO2

CO2 separation(amine absorption

process)

(a)

Adds $50 to $100/t CO2

avoided to cost of production

Cement kiln

Air

Fuel

Clinker Raw materialsCO2

CO2

condensation

Oxygen

separation

N2

Gas recycling

H2O(b)

O2

OXYFUEL


Geological storage possible where suitable anticlines capped by impervious rock exist


Ocean storage not an option owing to acidification, except where AWL is involved (bicarbonate solution rather than carbonic acid by scrubbing flue gasses with limestone)

0

1

2

3

4

2008 2050

Glo

ba

l C

O2 e

mis

sio

n f

rom

ce

me

nt

pro

du

cti

on

10

9 t

on

ne

pa




performance



and captured

Serie1






PRODCUTION

•RAW MATERIALS

•KILN EFFICIENCY

•LOW CARBON FUELS

SCMS




ALKALI ACTIVATED ALUMINO-SILICATE CEMENTS

•alkali-activated systems are claimed to require 60% less energy to produce than PC and to reduce CO2 emissions by 80%

CaO Al2O3

SiO2

C3S

C2S

C3S

2

CS

C3A C

12A

7CA CA

2CA

6

A3S

2

lime

belite

alite

wollastonite

cristobalite

tridymite

gehlenite

anorthite mullite

corundum

CA6CA2

CA

C12A7

C2AS

CAS2

rankinite

2400ºC

2200ºC

2000ºC

1800ºC

Earth’s crust low in Calow in CO2

PChigh in Cahigh in CO2

CaO Al2O3

SiO2

C3S

C2S

C3S

2

CS

C3A C

12A

7CA CA

2CA

6

A3S

2

lime

belite

alite

wollastonite

cristobalite

tridymite

gehlenite

anorthite mullite

corundum

CA6CA2

CA

C12A7

C2AS

CAS2

rankinite

2400ºC

2200ºC

2000ºC

1800ºC

Earth’s crust Consisting of 60% feldspars

PChigh in Cahigh in CO2

C0.8SHy

C1.7SHx

C3A.CS.H12

C3A.CC.H12

C3A.3CS.H32

CH

C3A

70% GBFS




Portland cement

stratlingite

silica gel

gibsite

C-S-Hss

20% Silica fume

Clays, PFA etc. from weathering of feldspars used as SCM or as geopolymer if alkalis topped up to original alkali/aluminate balance in feldspar

Instead of feldspars which are only stable at high temperature low T, much more open framework silicates, are formed which are closely related to the zeolites.

Despite the high alkali content, the alkalis are tied up in the silicates and a high pH pore solution cannot be maintained for protection of steel reinforcement against corrosion, which makes hybrid PC-alkali activated AS interesting.

C0.8SHy

C1.7SHx

CH

C3APortland cement

silica gel

gibsite

Fly ash and clay

Zeolite, e.g. natrolite

C3A.CS.H12

C3A.CC.H12

C3A.3CS.H32

Hydrate phase assemblage at high pozzolan contents and high alkali content

Na-zeolite + C-S-H + AFm/AFt

0

1

2

3

4

2008 2050

Glo

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O2 e

mis

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Serie1 Serie2 Serie3

Serie4 Serie5 Serie6






CONCLUDING COMMENTS

In order to achieve these reductions, the efforts must be global.

In some areas CCS may be more economical than maximum use of SCMs or biofuels and visa versa.

Alkali activated alumino-silicates can in theory replace up to 40% of Portland cement, but in regions where CCS is already required, would not provide additional CO2 avoidance.

Realistically these solutions can only take place within a global and transparent cap and trade system that does not distort competition.

developments needed in the production …webpages.mcgill.ca/staff/group3/aboyd1/web/conferences/amw...

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