Appendix 6: Low-carbon Cements – Barriers and Opportunities in Comparison to Conventional Portland Clinker
|
Technology |
Patent families |
Examples |
Phase (i) |
CO2 mitigation potential (% reduction vs. Portland clinker) |
Raw material availability |
Costs |
Energy demand |
Water demand |
Concrete properties |
Applications |
Standards |
|---|---|---|---|---|---|---|---|---|---|---|---|
|
Low- Portland-clinker cements |
934 |
LC3, CEMX, L3K, Ecocem |
Commercialized |
>70% (ii) |
Limited fly ash and slag supplies globally in long term, but plentiful supplies in China, Japan, India, South Africa and Australia in short term. (iii) Plentiful supplies of limestone for use as a filler. Limited availability of silica fume globally.(iv) Clays widely available. Using calcined clays as a clinker substitute will be particularly viable in locations with stockpiles of clays associated with large ceramics industries, e.g. China, Brazil and India. (v) Natural pozzolans will be important in locations with volcanic activity, particularly Greece, Italy, Indonesia and the US. (vi) |
Variable but can be lower with traditional SCMs. Decrease in operational costs of up to €3.1/t of cement with calcined clays. Retrofit costs: €8–12 million. (vii) Potentially higher with pre-processing if needed for calcined clays and natural pozzolans. |
Generally results in decreased energy demand, but this varies by material. GBFS results in decrease in thermal energy of 1,590 MJ/t of cement, but a small increase in electric energy of up to 10 kWh/t of cement. (viii) |
Varies depending on material. Water demand for fly ash, silica fume and calcined clays (when not using flash calcination) can be high, but using limestone as a filler can lower water demand. (ix) |
Vary depending on material and proportion of clinker replaced. Many high-blend cements have low early-strength development but can achieve superior durability later on. |
A wide range of applications. High-blend cements made with slag and fly ash have been used in structural and non-structural applications in many different contexts. (x) |
High-blend cements using traditional SCMs are covered by European and US standards. Non-traditional SCMs are included in European standards, but are often excluded, not mentioned or allowed only with restriction in most exposure classes in European concrete standards. (xi) |
|
Geopolymers and alkali-activated binders |
418 |
banahCEM, Zeobond cement |
Commercialized |
>90% (xii) |
Same as for low-Portland-clinker cements. Limited by current global production of sodium silicate, needed as an activator. (xiii) Waste glass could be used in place of sodium silicate as an activator. (xiv) |
Cost-competitive in some contexts. In Australia, geopolymer cements are currently 10–15% more expensive than Portland cement. (xv) |
Varies depending on energy input required for manufacturing the activator, e.g. Sodium silicate often requires a high energy input. (xvi) |
Ceratech claims that its geopolymers use 50% less water. (xvii) |
Can match the performance of Portland cement concrete. Historically, quality has varied depending on composition, but predictable performance is now claimed. (xviii) |
A wide range of applications. Geopolymer cements have been used in major infrastructure and multi-storey buildings in Australia. (xix) |
Not covered by standards. Geopolymer concrete standard being developed in Australia, but will likely take several years. Several organizations have recognized geopolymer concretes in their own standards. (xx) |
|
Belite-rich Portland cements (BPC) |
20 |
Commercialized |
~10% (xxi) |
High (same materials as traditional cement). (xxii) |
Can be produced in conventional cement plants. (xxiii) Retrofit costs: €0–12 million. Increase in operational costs: €2–3.8/t of cement. (xxiv) |
Varies, thermal energy demand can decrease by 150–200 MJ/t of clinker. Electric energy demand can increase by 20–40 kWh/t of cement. (xxv) |
Less water needed for hydration. (xxvi) |
Slower strength development than traditional cement, but expected to be more durable. (xxvii) |
Limited to applications where low early-strength development is less of an issue, e.g. used in dams in China. Well suited to applications in hot climates. (xxviii) |
Meets Chinese standards for Portland cements. (xxix) |
|
|
Belitic clinkers containing ye’elimite (CSA) |
33 |
Commercialized |
~50% (xxx) |
Limited bauxite supplies if high ye’elimite content is targeted, but more potential where bauxite waste is available, for example in large producing countries such as Australia, China, Brazil, Malaysia and India.xxxi Variable sulphur supplies. (xxxii) |
Can be produced in conventional cement plants. (xxxiii) Higher raw material costs than for Portland cement. |
30–50% less grinding energy required compared with OPC. (xxxiv) |
Similar performance to Portland cement appears feasible. Concretes can show less carbonation and chloride migration resistance. (xxxv) |
Mostly used in applications in China where the additional cost can be justified. (xxxvi) |
Small number of compositions covered by existing Chinese CSA standards. European standard is being drafted. (xxxvii) |
||
|
BYF clinker (also known as BCSA clinkers) |
23 |
Aether |
Demonstration |
>20% (xxxviii) |
Similar to CSA, however, BYF clinkers can have a lower ye’elimite content than CSA, meaning relatively abundant aluminium sources such as clays and coal ashes can be used in place of scarce concentrated aluminium sources such as bauxite. (xxxix) |
Similar to CSA, however, BYF clinkers can have a lower ye’elimite content than CSA, meaning relatively cheap aluminium sources such as clays and coal ashes can be used in place of concentrated aluminium sources such as bauxite, which can be expensive. (xl) |
Same as for CSA. |
Data from EU’s LIFE programme indicate similar strength development rate to OPC, better sulphate resistance and lower drying shrinkage. Other durability tests are still under way. (xli) |
Only demonstrated in a limited number of applications, but in theory can be used for a very wide range of applications. Lower setting and hardening times mean that BYF clinker may have an advantage in precast concretes but can also be adapted for use in ready-mixed concrete applications. (xlii) |
Same as for CSA. |
|
|
Low-carbonate clinkers with pre-hydrated calcium silicates |
8 |
Celitement |
Demonstration |
>50% (xliii) |
High (same materials as traditional cement). |
Roughly similar to costs for producing OPC clinker. (xliv) Similar raw material costs. |
50% less energy required. (xlv) Potential increase in electricity needed for activation grinding. |
Less water needed. (xlvi) |
Similar performance to traditional cement. Strength development, final strength and hydration vary in the same range as for conventional cement. Increased reactivity over belite-rich Portland cement clinkers. (xlvii) |
May be suitable for a wide variety of applications, but particularly for high-durability applications. (xlviii) |
Not covered by existing standards. (xlix) |
|
Carbonatable calcium silicate clinkers(CCSC) |
15 |
Solidia, Calera |
Pilot |
>70% (l) |
High (same materials as traditional cement). (li) Variable supply of pure CO2. |
Can be produced in conventional cement plants. (lii) Similar raw material costs to Portland cement. |
Less grinding energy required. (liii) |
Solidia claims around 80% less water is consumed. (liv) |
Similar performance to traditional concretes is claimed. (lv) |
Limited to precast applications for now. Not expected to be suitable for reinforced-concrete applications. Some on-site curing applications may be possible. (lvi) |
Precast concretes can be sold under local technical approvals and do not necessarily require standardization at the national level. However, national standards are being sought. (lvii) |
|
Magnesium-based cements |
24 |
Novacem |
Research |
>100 % (lviii) |
Plentiful but localized supply of basic magnesium silicates. Limited supply of natural magnesite. |
Too early to assess, as no established manufacturing process. (lix) |
Too early to assess, as no established manufacturing process but could in theory require less energy to produce. (lx) |
Too early to assess. Very little information available on durability. (lxi) |
Too early to assess. |
Notes
(i) International Energy Agency (2017), Energy Technology Perspectives 2017.
(ii) Schuldyakov, K. V., Kramar, L. Y. and Trofimov, B. Y. (2016), ‘The Properties of Slag Cement and Its Influence on the Structure of Hardened Cement Paste’, Procedia Engineering, International Conference on Industrial Engineering, doi: 10.1016/j.proeng.2016.07.202 (accessed 9 Feb. 2018).
(iii) Scrivener, John and Gartner (2016), Eco-efficient cements.
(iv) European Cement Research Academy and Cement Sustainability Initiative (2017), CSI/ECRA-Technology Papers 2017.
(v) Scrivener, John and Gartner (2016), Eco-efficient cements.
(vi) Ibid.
(vii) European Cement Research Academy and Cement Sustainability Initiative (2017), CSI/ECRA-Technology Papers 2017.
(viii) Ibid.
(ix) European Cement Research Academy and Cement Sustainability Initiative (2017), CSI/ECRA-Technology Papers 2017; Beyond Zero Emissions (2017), Zero Carbon Industry Plan: Rethinking Cement; Scrivener, John and Gartner (2016), Eco-efficient cements.
(x) Beyond Zero Emissions (2017), Zero Carbon Industry Plan: Rethinking Cement.
(xi) Müller (2011), ‘Use of cement in concrete according to European standard EN 206-1’.
(xii) Beyond Zero Emissions (2017), Zero Carbon Industry Plan: Rethinking Cement.
(xiii) Scrivener, John and Gartner (2016), Eco-efficient cements.
(xiv) Beyond Zero Emissions (2017), Zero Carbon Industry Plan: Rethinking Cement.
(xv) Ibid.
(xvi) Ibid.
(xvii) Ibid.
(xviii) Beyond Zero Emissions (2017), Zero Carbon Industry Plan: Rethinking Cement; Taylor (2013), Novel cements; Van Deventer, Provis, and Duxson (2012), ‘Technical and commercial progress in the adoption of geopolymer cement’.
(xix) Beyond Zero Emissions (2017), Zero Carbon Industry Plan: Rethinking Cement.
(xx) Ibid.
(xxi) Scrivener, John and Gartner (2016), Eco-efficient cements.
(xxii) Gartner and Sui (2017), ‘Alternative cement clinkers’.
(xxiii) Ibid.
(xxiv) European Cement Research Academy and Cement Sustainability Initiative (2017), CSI/ECRA-Technology Papers 2017.
(xxv) Ibid.
(xxvi) Ibid.
(xxvii) European Cement Research Academy and Cement Sustainability Initiative (2017), CSI/ECRA-Technology Papers 2017; Gartner and Sui (2017), ‘Alternative cement clinkers’.
(xxviii) Beyond Zero Emissions (2017), Zero Carbon Industry Plan: Rethinking Cement; Gartner and Sui (2017), ‘Alternative cement clinkers’.
(xxix) Gartner and Sui (2017), ‘Alternative cement clinkers’.
(xxx) Quillin, (2010), ‘Low-CO2 Cements based on Calcium Sulfoaluminate’.
(xxxi) Gartner and Sui (2017), ‘Alternative cement clinkers’; Scrivener, John and Gartner (2016), Eco-efficient cements.
(xxxii) Gartner and Sui (2017), ‘Alternative cement clinkers’.
(xxxiii) Ibid.
(xxxiv) European Cement Research Academy and Cement Sustainability Initiative (2017), CSI/ECRA-Technology Papers 2017.
(xxxv) European Cement Research Academy and Cement Sustainability Initiative (2017), CSI/ECRA-Technology Papers 2017; Taylor (2013), Novel cements.
(xxxvi) Scrivener, John and Gartner (2016), Eco-efficient cements.
(xxxvii) Gartner and Sui (2017), ‘Alternative cement clinkers’.
(xxxviii) Scrivener, John and Gartner (2016), Eco-efficient cements.
(xxxix) Ibid.
(xl) Ibid.
(xli) Gartner and Sui (2017), ‘Alternative cement clinkers’.
(xlii) Ibid.
(xliii) Celitement (2017), ‘Celitement Binders’.
(xliv) Stemmermann, P., Beuchle, G., Garbev, K. and Schweike, U. (2011), ‘Celitement’, in ‘Innovations in Sustainable Development’, https://josbrouwers.bwk.tue.nl/publications/Other27.pdf (accessed 19 Mar. 2018).
(xlv) Stemmerman, P. (2017), ‘Celitement – Reducing the CO2 Footprint of Cement’, presentation, COP 23, 7 November 2017, http://climatestrategies.org/wp-content/uploads/2017/10/Peter-Stemmerma… (accessed 19 Mar. 2018).
(xlvi) Stemmermann et al. (2011), ‘Celitement’.
(xlvii) European Cement Research Academy and Cement Sustainability Initiative (2017), CSI/ECRA-Technology Papers 2017; Scrivener, John and Gartner (2016), Eco-efficient cements.
(xlviii) European Cement Research Academy and Cement Sustainability Initiative (2017), CSI/ECRA-Technology Papers 2017.
(xlix) Dewald and Achternbosch (2015), ‘Why more sustainable cements failed so far?’.
(l) Jain, J., Deo, O., Sahu, S. and DeCristofaro, N. (2014), ‘Solidia Concrete: Part Two of a Series Exploring the Chemical Properties and Performance Results of Sustainable Solidia Cement and Solidia Concrete’, Solidia Technologies, 19 February 2014, http://solidiatech.com/wp-content/uploads/2014/02/Solidia-Concrete-Whit… (accessed 19 Mar. 2018).
(li) Gartner and Sui (2017), ‘Alternative cement clinkers’.
(lii) lbid.
(liii) Sahu, S. and DeCristofaro, N. (2013), ‘Solidia Cement: Part One of a Two-Part Series Exploring the Chemical Properties and Performance Results of Sustainable Solidia Cement and Solidia Concrete’, Solidia Technologies, 17 December 2013, http://solidiatech.com/wp-content/uploads/2014/02/Solidia-Cement-White-… (accessed 19 Mar. 2018).
(liv) Oil and Gas Climate Initiative (2017), ‘OCGI announces three investments in low emissions technologies and launches third annual report’, press release, 27 October 2017, http://oilandgasclimateinitiative.com/ogci-announces-three-investments-… (accessed 19 Mar. 2018).
(lv) European Cement Research Academy and Cement Sustainability Initiative (2017), CSI/ECRA-Technology Papers 2017; Gartner and Sui (2017), ‘Alternative cement clinkers’.
(lvi) Ibid.
(lvii) Gartner and Sui (2017), ‘Alternative cement clinkers’.
(lvii) Ibid.
(lix) Ibid.
(lx) Ibid.
(lxi) Ibid.