lafarge

7th CSI Forum 7th CSI Forum -- VancouverVancouverInnovative approaches to Innovative approaches to

reduce COreduce CO22 emissionsemissions

GGüünther Walentanther Walenta

Lafarge LCRLafarge LCR02/10/201302/10/2013

Date 27th CSI Forum - CO 2 reduction solutions – G. Walenta - Lafarge Centre de Recherche

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LAFARGE & CO2 - Some Figures

� In 2012, LAFARGE produced 153 Mt cement and emitted ~94 Mt CO2

� About 65% of the CO2 related to decarbonation of limestone and 35% from fuel combustion

� Between 1990-2010, Lafarge decreased net CO2 emissions by 20% (from 774 to 630 kg CO2/tcement ) i.e. a reduction of ~25 Mt CO2/yr

� Since 2011 new commitment : minus 33% of net CO2 emissions reduction from 1990 to 2020

� Main conventional levers used to reduce CO2:

� Reduce specific heat consumption of the cement kiln

� Increase cementitious additions into the cement (slag, FA, pozzolans, limestone…)

� Substitution of fuels (animal meal, tires, shredded wastes…)


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Some potential non conventional solutions

� Although the conventional industrial levers still need to be developed, we think they will soon come to a limit and that we will not be able divide our CO2 emissions by factor 4 (by year 2050)

⇒ Other non conventional means need to be developed:

� Carbon Capture & Sequestration (CCS)

� Carbon Capture & Transformation (CCT)

Micro- Algae

� Low CO2 clinker development: AETHER


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Algae ponds – Photo-bio-reactors (PBR)

� Algae growing based on Photosynthetic reaction

Sunlight

+ + CO2 + H2O Biomass + O2

Micro-algae

Bio-fuels: biodiesel / bioethanol / methanisationHigh value products (omega-3…)

Vertical tubular PBR

Surface needed: ~4 km²

485 €/t CO2 avoided(without CAPEX)

Total CO 2 reduction: 50% CO2

But:Business model not valid

Significant technology breakthrough needed for indu strial use


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Lafarge’s objectives for Aether :A low CO2 clinker for all types of cement

� Objective :

� Develop a new class of clinkers for making cements with similar mechanical performances to conventional OPC s, and which can be produced in existing PC plants , while giving significantly lower CO 2 emissions (20%-30%) in production

� Targeting ‘Niche products ’ & mainstream products

� Not looking for specific applications, but looking to replace the ordinary clinker

� Ready mix, Precast…


What is AETHER?

� Aether is a new, patented* class of low-CO2

cements based on BCSAF clinkers containing:

� Belite: C2S 40 – 75%

� Calcium sulfoaluminate (ye’elimite): C4A3$ 15 - 35 %

� Ferrite : C2(A,F) 5 – 25%

*Gartner, E., and Li, G., 2006. World Patent Application WO2006/018569 A2


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~29%~12%~11%~5%~37%~3%

LOISiO2

Al2O3

Fe2O3

CaOSO3

Aether raw mix *

Aether cement: CO 2 emissions and manufacturing

‘Portland’ raw mix

LOISiO2

Al2O3

Fe2O3

CaOSO3

~35%~14%~3%~3%

~43%~0.3%

C3S

C3A

C2S

C4AF

‘Portland’clinker

~65%

~6%

~15%

~12%

C4A3$

C2S

C2(A,F)

Aether clinker *

~25%

~55%

~20%

� Aether main characteristics vs. Portland:

� Higher Alumina and SO3 content and lower LOI of the raw mix = lower CaCO3

� No C3S, but C4A3$ & higher C2S content

* a potential Aether composition


Overview CSA and belite based binder technologies

� Chemistry & mineralogy different from OPC

Buzzi (NEXT)Heidelberger (BCT)

Italcementi (ALIPRE)Vicat (ALPENAT)

Lafarge (AETHER)

Different approaches (not exhaustive):

� C3S is no longer major phase; C2S takes on more importance (15 to 75%)� Presence of C4A3$ (15% to 70%), C5S2$, C$

� Raw materials similar to OPC, but generally higher alumina needs –higher raw material cost - use of alternative raw materials is preferred

� Lower limestone & burning temperatures = lower CO2 emissions� Wide range of compositions, allowing a high variety of properties

� Higher short term strength, etc…,

Some common points:


Aether industrial trial 2012– Le Teil (South of France)

Timing: 06/12/2012 to 18/12/2012

~100 Participants2 times 5000t of good AETHER clinker produced

Rotary kilnLength ~70m


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The manufacturing of Aether generates 20 to 30% less CO2 per tonne of cement than pure Portland

cement (CEM (I) type)

� Aether clinkers can be produced :

� in kilns designed for Portland production (Lepol 2011 & Dry 2012)

� using similar process parameters and fuels

� using mainly conventional raw materials

� at lower temperatures (≈1225 -1300°C) than for Portland cement clinker (1400 – 1500°C)

� with significantly lower energy than Portland cement clinker

� Aether cement grinding energy is lower than for OPC (based on lab grinding -must be confirmed industrially)

Aether : Experiences from Industrial trials: CO2 emissions and manufacturing facts


Ongoing & next steps

Evaluate clinker & cement properties � Mineralogy & Chemistry

� Standard motar & Concrete testing

� Durability testing

� Creation of suitable standards

� Identify most promising AETHER applications


Results AETHERTM Concrete testsPrecast Concrete application

Slump life: 45 min -1 hour Slump Class: S3-S4Strenghts: 6 hours: 20 MPa (without heating

24 hours: 27 MPa7 days: 41 MPa

28 days: 48 MPa


Strength development and dimensional variations

�Strength development (will continue for 10 years)

o in water (40, 68, 95°F, ie: 5, 20, 35°C), o in air (68°F / 20°C, 65%RH)

� All results comparable to OPC (6 months)

Durability Results AETHERTM

Concrete

Ongoing study with Lafarge - BRE (British Research Establishment)

with European Union support (Life+ project)

0 1y

-250

-500 µm/m

dl/l

time

Aether®

Portland

Typical mix for « wet precast »

W/C=0.4

� Dimensional variations Results (1year):

� Drying shrinkage reduced 50%


Resistance to agressive medium

� Use of alkali reactive aggregates:

� In progress

� Possibility to use embedded steel reinforcement:

� Protective passivating layer on the surface of embedded steel rebar confirmed

� further study foreseen (PhD)


Concrete

� Wear ratingo Class 5 sulfate at 5°C

o 3% citric acid at 20°C

� min. equivalent to OPC(still in progress)


Risk of corrosion of embedded steel corrosion


Concrete

� Resistance to carbonation for laboratory & natural exposure� Carbonation equivalent to a blended Portland cement with

similar CO2 saving

� Resistance to chloride ingress

� Matches equivalent OPC concretes


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AETHER cements based on clinkers containing belite, calcium sulfoaluminate and ferrite seem to be a promising alternative toPortland cements.

� 20%-30% Reduction of CO2 emissions relative to Portland cements

� Use of similar raw materials and production possible in existing industrial installations

� Similar concrete performance to Portland cements

�But more research is needed on process, hydration and durability, in order to develop appropriate standards, before Aether cements can be considered a large-scale alternative to Portland cement.

Aether: Conclusion


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2011 Team AETHER TM before returning to the individual working groups: Nationalities:Brazil, Canada, China, Germany, England, France, Austria, Spain


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Thank you !

Discussion…

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conventional solutions

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