Solidia Cement™ reduces embodied CO2 of concrete by ~70% while increasing performance using incumbent industrial equipment and processes.
Solidia Technologies has developed a novel cementitious binder; this synthesized calcium-metasilicate, Solidia Cement™, is carbonated to form concrete end-products that show enhanced strength and durability as compared to traditional Portland cement concrete. The cement is manufactured using traditional Portland cement kilns and raw materials, eliminating the need for new capital infrastructure or supply chains. Solidia Cement consumes less limestone and is synthesized at substantially lower temperatures than Portland cement (1250C vs 1450C), resulting in a ~30% reduction in CO2 emissions through lower calcination and energy use at the cement production stage.
Concrete products are formed with Solidia Cement and aggregates typically used with Portland cement products. This product mix is reacted with CO2 gas at atmospheric pressure at 60C to form a durable binding matrix, achieving complete cure and full strength within hours rather than weeks. When waste CO2 is used as the reactant, lifecycle emissions of the concrete are reduced by an additional ~40%.
Due to higher strength molecular bonding, reduced permeability and absence of alkali silica reactivity, Solidia ConcreteTM outperforms traditional concrete in a range of properties including compressive strength, abrasion resistance, and durability. Higher strength combined with lower energy consumption and shorter processing time all contribute to overall cost savings.
Category of the action
Industrial Efficiency: Cement Industry
What actions do you propose?
There are two major milestones to be achieved for full deployment of this technology: (1) full-scale adoption by cement and concrete manufacturers and (2) revision of regulatory standards and test methods to accommodate a carbonated rather than hydraulic based concrete system. Both sets of activities will be undertaken in tandem, progress in each enabling the other.
- Solidia Cement ™ and Solidia Concrete™ Technology Deployment
Solidia Technologies has developed a “green” cementitious binder that consumes ~30% less energy and emits ~30% less CO2 than Portland cement. This new binder, referred to as Solidia Cement, is predominantly comprised of calcium metasilicate (CaSiO3) that can either be naturally mined or synthesized by solid-state reaction. The naturally mined mineral results in a carbon neutral cement and potentially carbon negative concrete product. While use of the naturally mined silicate eliminates the need for preliminary calcining and solid-state reaction (process steps in Portland cement manufacturing that result in emissions of 0.8 – 1.0 tonne of CO2 for each tonne of cement produced), the naturally occurring silicate is mined in limited quantities in remote geographical regions; it is not cost-competitive when compared to traditional Portland cement binder and so would have limited impact.
To address this deficiency, Solidia Technologies has discovered a method for synthesizing the CaSiO3 using existing Portland cement kilns and globally available precursor materials; predominantly limestone and shale. By shifting the ratio of CaO to SiO2 in the mix and firing at 1250°C instead of 1450°C (the temperature used to produce Portland cement clinker), a cement composition of CaSiO3 is achieved rather than the standard Ca3SiO5-Ca2SiO4. The reduced energy and limestone decomposition combine to reduce CO2 emissions in cement manufacturing by approximately 30%. Because of the use of incumbent capital equipment and supply chains, adoption of this technology by the cement industry is technologically relatively simple. An appetite for innovation coupled with downstream demand for this cement will drive adoption.
As with Portland cement concrete, fabrication of Solidia Concrete products is accomplished by mixing Solidia cement with standard aggregate materials (sand and crushed stone), but with a minimal amount of water. Rather than adding as much as 50wt% water to enable binder reaction, Solidia Cement is carbonated with CO2 in a closed chamber at moderate temperature (60C or less) and ambient pressure (724 torr) to form CaCO3 and SiO2. These new phases form a binding matrix to create fully cured, stable concrete with no residual water or alkali silica reactivity. Full cure is achieved in a matter of hours rather than days or weeks required for hydration of Portland cement. Solidia Concrete is produced using the same mixing, forming and finishing equipment used to make traditional concrete; the only change is the addition of the means to introduce CO2 into the mix.
There is a unique opportunity for Solidia to utilize waste CO2 captured from the combustion flue gas of industrial emitters, including cement manufacturing facilities. This sequestration enables an additional ~40% reduction in lifecycle CO2 emissions, for a total ~70% reduction in embodied CO2 as compared to Portland cement based concrete.
As shown in the attached graph, emissions from the cement industry are estimated to grow at a rapid rate over the next 20 years. The International Energy Agency (IEA) and the World Business Council for Sustainable Development estimate that the cement industry would have to reduce emissions by 66% as compared to 1990 levels to limit global temperature rise to 2-3°C by 2050; global targets set to date will not accomplish this goal. Efforts to use alternative energy, enhance energy efficiency, and substitute binder for supplementary cementitious materials (such as blast furnace slag and fly-ash) will help lower emissions but will not enable achievement of the IEA/WBCSD goal by themselves. Full adoption of Solidia Cement and Concrete production in conjunction with existing efforts can potentially help the cement industry achieve the emission reductions needed to help avert global temperature rise.
- Regulatory Standards Alignment
Perhaps the greatest challenge to enabling use of Solidia’s technology is the modification of existing regulatory standards and testing methodologies. There is a strong need for partnership with regulatory agencies to revise current specifications and regulations and create performance based specifications that will better reflect product performance rather than manufacturing technique. The regulatory agencies governing these standards range along the full spectrum from municipal to state, federal, regional, and international. Solidia proposes (and has already begun) to engage regulatory agencies including Federal and State Departments of Transportation, ASTM to the FHWA, ASHTO, ICC and ACI as well as industry partners to build a culture of openness to innovation and acceptance of technologies based on relevant validation criteria and test methods. This task is critical toward enabling worldwide implementation of Solidia Cement and Solidia Concrete.
Who will take these actions?
Solidia is actively growing an ecosystem of stakeholders and will continue to include and expand on these partnerships through development and implementation of its cement and concrete technology.
- Researchers and Developers: In addition to the Solidia Technologies team, these include faculty and students in the Riman Group at Rutgers, The State University of New Jersey, the North Central Superpave Center at Purdue University, Argonne National Laboratories, and the Energy and Environment Research Center at the University of North Dakota Grand Forks to continue with process improvements and innovations. ThyssenKrupp Polysius and IBU-tec have and will continue to help with process development for Cement production.
- Cement Producers: Both local and global partners who will pilot and implement Solidia Cement manufacturing.
- Building Materials Manufacturers: Local and global partners who will pilot and implement final production of non-structural and structural pre-cast and cast-in-place applications of Solidia Concrete.
- Industrial Emitters: Producers of CO2 such as manufacturing facilities with deployed oxy-combustion furnaces, glass, steel and chemical manufacturers, and landfill gas emitters (to name a few) that will be the source of waste stream CO2.
- Regulatory and Test Agencies: Including Federal and State Departments of Transportation, ASTM, FHWA, ACI, CCI, AASHTO and their international equivalents, to assist with the development of relevant standards and specifications and with product validation. The CTL Group (formerly part of the Portland Cement Association) does all of Solidia’s third party testing of concrete properties.
- Thought Leaders and Market Players: These include architects, general contractors, public policy makers and other influencers of behavioral change who will ultimately enable growth in demand for Solidia Concrete.
Where will these actions be taken?
Development of Solidia Cement technology and its applications is performed predominantly at the company headquarters in Piscataway, NJ. At the same time, Solidia has developed partnerships with universities, manufacturers, and government agencies throughout the US and the world as a part of its strategic plan for ensuring technical readiness, manufacturability, performance verification and compliance with government and industrial regulations.
Solidia will focus deployment in countries that impose a liability for CO2 emissions and rapidly growing BRIC countries in the short term. Solidia’s strategy is to prioritize those regions of the world with the greatest cement production rates and the greatest commitment to GHG reduction (2,3). By targeting these locations up-front, Solidia will have engaged over 80% of global concrete producers, paving the way for subsequent worldwide implementation.
How much will emissions be reduced or sequestered vs. business as usual levels?
Scientific literature suggests that limiting average global temperature rise to 2 °C above pre-industrial levels – the target internationally adopted in UN climate negotiations – is possible if cumulative emissions in the 2000–2050 period do not exceed 1,500 Gt CO2 (3). With an accumulation of 420 Gt calculated between 2000-2011, the goal demands a cumulative CO2 emission of 1080 Gt over the next 39 years. As the cement industry continues to grow, controlling emissions will become more and more important. As shown in the attached graph, full deployment of Solidia Cement and Concrete in conjunction with full deployment of energy efficiency, alternative energy and binder replacement strategies, would make the cement industry almost carbon neutral.
What are other key benefits?
Solidia Concrete’s additional benefits include
- Improved Physical Properties: Compressive strength and abrasion resistance are 6 times greater than that of comparable Portland cement concrete, increasing product life and reducing maintenance costs
- Improved Durability: Resistance to microcracking under freeze/thaw, low permeability and no ASR susceptibility increase product life and reduce maintenance
- Reduced Toxins: Lower cement processing temperature yields less NOx, SO2, mercury, dust and other toxins along with CO2
- Lower Production Cost: Energy reduction in the production of cement results in lower cost of the binder; improved workability, reduced curing time, and enhanced physical properties could provide lower cost to the concrete manufacturer
What are the proposal’s costs?
Significant costs associated with the implementation of this technology come from human effort. This includes:
- R&D Activities: Research is needed to expand the technology and broaden the field of applications, as well as to improve CO2 capture and conditioning. Validation testing of products at recognized third-party facilities forms a large part of this work.
- Regulatory Activities: Significant effort is needed to develop a regulatory environment that enables broad industry acceptance of Solidia Cement and Concrete. This includes engagement with a wide variety of industry and policy-making stakeholders, locally and globally. These activities are expected to be substantial beyond the anticipated 5-10 year technology development timeline.
- Marketing Activities: Education of the industry from cement manufacturers to concrete installation line workers will be crucial to instilling a sense of confidence in this new material in an industry that is traditionally resistant to transformative innovation. Education and confidence building will be core to the introduction of this technology in every local market.
Solidia has already raised some of the investment it believes is needed to accomplish these goals.
- Short Term (5-15 years): The focus over the next 5-15 years will be the development of fundamental science and industrial and regulatory infrastructure that will enable expansion in applications from non-structural pre-cast concrete to structural pre-cast and cast-in-place products, thus encompassing the full spectrum of cement and concrete applications. By the end of this period, all concrete applications will be market-ready. In 2012, Solidia began to deploy non-structural pre-cast concrete through technology licensing. Target marketplaces for the technology currently include countries with an appetite for CO2 emission reductions (because of legislated liability) and rapidly growing emerging markets.
- Mid-Term (15-50 years): During this period, the focus will be on educating producers and policy makers, changing behavior to improve market acceptance of the technology, and continuing execution of worldwide deployment. Solidia hopes to achieve full-deployment of non-structural and structural pre-cast concrete applications. Cast-in-place deployment is expected to be emerging.
- Long Term (50-100 years): Solidia hopes to achieve full deployment in all applications and in all global regions.
The technological approach of this proposal is focused on alternative binder and reaction chemistry, which is substantially different from all other proposals submitted to date. There are currently three proposals listed for Profitably Removing Emissions from Cement: one uses an alternative energy source; a second uses SCMs to replace Portland cement, and a third works to improve binder efficiency. Outside of this contest, global manufacturers have substituted 10-30wt% clinker in cement, turned to dry processing with preheating and pre-calcining to save ~25% in thermal energy use, or have used alternative fuels (including alternative fossil fuels and biomass), to achieve between 30-60% reduction in thermal energy use (6). These other emissions reduction strategies could be easily incorporated into the Solidia Cement and Concrete manufacturing processes to further decrease embodied CO2 beyond the already substantial ~70% reduction possible.
- Gupta A (2011). Cement Primer Report. The Gigaton Throwdown Initiative, Gigaton Analysis of the Cement Industry: The Case for Rapid Adoption of Proven Technologies. Washington DC: The Carbon War Room, March.
- CEMBUREAU (2012). Activity Report 2011. Bruxelles: The European Cement Association, May.
- Olivier JGJ, Janssens-Maenhout G, Peters JAHW (2012). Trends in global CO2 emissions, 2012 Report. The Hague: PBL Netherlands Environmental Assessment Agency and Institute for Environment and Sustainability (IES) of the European Commission’s Joint Research Centre (JRC).
- Ochsendorf J, Norford LK, Brown D, Durschlag H, Hsu SL, Love A, Santero N, Swei O, Webb A, Wildnauer M (2011). Methods, Impacts, and Opportunities in the Concrete Building Life Cycle. Cambridge MA: Concrete Sustainability Hub, Massachusetts Institute of Technology Department of Civil and Environmental Engineering, Research Report R11-01, August.
- NRMCA (2012). Concrete CO2 Fact Sheet. Silver Springs MD: National Ready Mixed Concrete Association, NRMCA Publication 2PCO2, February.
- WBCSD-CSI (2009). Cement Industry Energy and CO2 Performance: “Getting the Numbers Right.” Geneva: World Business Council for Sustainable Development Cement Sustainability Initiative.