Displaying items by tag: decarbonisation

China: A new study from Hong Kong Polytechnic University showcases sustainable cement production methods, focusing on low-clinker cements and alternative solutions for incinerator fly ash (IFA). The research demonstrates that using carbonated-washed IFA mixed with slag, coal fly ash, or metakaolin can replace 60% of Portland cement, forming ternary blended cement. This approach reportedly reduces the carbon footprint of cement production.

The study found that slag was the most effective, improving pore structure and increasing ettringite and hemicarboaluminate formation with a blend of 40% slag and 20% IFA. It achieved 90% of the compressive strength of pure Portland cement after 90 days.

The researchers said "This study demonstrated the promising potential of the blended cements to simultaneously divert IFA from landfills and reduce the clinker content of cement."

Philippines: A recent study from Cebu, Philippines presents a method for reducing greenhouse emissions in the cement industry. The research, supported by the Department of Science & Technology (DOST) of the Philippines, focuses on partially substituting cement with coal fly ash (CFA). According to the University of San Carlos researchers, CFA's efficacy as a cement substitute depends on its source, with variations in quality, performance, and water requirements when used in paste and mortar formulations.

The study evaluated CFA from a Philippine power plant, examining its use as a partial cement substitute. Researchers designed paste and mortar mixtures with different CFA-to-binder ratios and water-to-binder ratios. The study revealed that increasing the amount of CFA in cement up to 20% by weight could enhance compressive strength, ‘outperforming’ pure cement mixtures.

The study concluded that substituting a portion of cement with CFA not only reduces greenhouse gas emissions but also improves the compressive strength of the resultant material.

Thailand: Chair of the Thai Cement Manufacturers Association (TCMA), Dr Chana Poomee, announced the company’s new strategy, called 'TCMA Synergising the Actions toward Net Zero 2050'. This strategy aims to drive the cement industry towards clean energy transition, connect with global green funds and address climate change.

The vision involves four key missions for 2024-2026, including developing low-carbon cement, enhancing resource-efficient mining practices, building an integrated waste-to-value ecosystem, and transitioning to clean energy.

The TCMA also aims to reduce its CO₂ emissions by 6.9Mt/yr by 2030. Collaborations with various partners, including the Thailand Fellowship Cement Manufacturers and the Thai Bankers Association, are planned to leverage innovation and government policy support.

US: The Portland Cement Association (PCA) has commended the Connecticut Department of Transportation's approval of Portland limestone cement (PLC), marking its acceptance in all US states and the District of Columbia. PLC, with increased limestone content, maintains traditional Portland cement's efficacy but reduces CO₂ emissions by up to 10%. The US avoided more than 4Mt of CO₂ emissions in 2023 by using PLC and other blended cements. This achievement coincides with growing cement consumption by state transportation departments, fuelled by the Bipartisan Infrastructure Law.

Mike Ireland, president and CEO of PCA, said "This milestone is a huge step forward for sustainable American construction. Switching to PLC promises to save millions of tonnes of CO₂. Using a lower-emission product that meets all the performance requirements of traditional cement means the construction sector can build with durability, safety and sustainability in mind."

Brazil: Votorantim Cimentos has made progress in reducing its carbon footprint, reporting embodied CO₂ emissions of 556kg/t of cement produced in 2023, a 4% year-on-year decrease. The company aims to reach a target of 475kg of CO₂/t by 2030, aligning with the Science Based Target initiative standards.

The company's decarbonisation strategy involves four stages: co-processing, which involves substituting fossil fuel with biomass and waste; use of cementitious materials to replace clinker; enhancing energy efficiency and use of renewable energy; and developing new technologies and materials, including carbon capture. In 2023, Votorantim Cimentos achieved a 31% global thermal substitution rate through co-processing, an increase from 26.5% in 2022, with a goal of reaching 53% by 2030. The clinker factor was reduced to 72.8% in 2023 from 73.9% in 2022. This reduction means a decrease in emissions, with a target clinker factor of 68% set for 2030. Additionally, 35.1% of the electricity consumed by Votorantim Cimentos in 2023 came from renewable sources, an increase from 22.9% in 2022, with an aim of 45% by 2030.

Álvaro Lorenz, global director of sustainability, institutional relations, product development, engineering, and energy at Votorantim Cimentos, said "The most competitive and sustainable companies will be those with the lowest emissions. In all countries where we operate, we are committed to advancing in our decarbonisation journey, in line with our goal of producing carbon-neutral concrete by 2050."

Votorantim Cimentos’ environmental efforts were recognised with an A score by CDP and a Top-Rated Industry company distinction by Sustainalytics in the Latin American building materials sector. The company also announced a US$989m investment to further reduce its CO₂ emissions. This includes a project at Salto de Pirapora to increase thermal substitution, with expected completion by 2028. Votorantim Cimentos has also started constructing a solar energy complex in Paracatu, with an estimated capacity of 470MWp.

South Korea: A recent study from Daejeon explored the potential of low-lime calcium silicate cement as a low CO₂ emission alternative to Ordinary Portland Cement. Researchers from the Korea Institute of Geoscience and Mineral Resources examined the setting and flow characteristics of a mixture of Ordinary Portland Cement and low-lime calcium silicate cement under carbonation curing conditions. The study was financially supported by the Ministry of Trade, Industry & Energy's industrial strategic technology development programme.

The study aimed to explore the reaction and microstructural characteristics of these cement pastes. The low-lime calcium silicate cement was synthesised using limestone and silica fume, with varying proportions added to the Portland cement pastes. The research findings suggest improvements in compressive strength with the inclusion of 30% or more low-lime calcium silicate cement, highlighting its ability to enhance the durability and sustainability of construction materials.

US: A research team from Lehigh University has won a three-year, US$2m grant from the Department of Energy's industrial efficiency and decarbonisation office for a project on concrete decarbonisation. The team, including Carlos Romero, director of Lehigh's Energy Research Centre, aims to develop a sustainable concrete binder using calcined clay, reducing emissions associated with Ordinary Portland Cement production. The project collaborates with Buzzi Unicem USA and focuses on processing and testing calcined clay to mimic the properties of conventional cement.

Lehigh's team will explore various low-grade calcined clays, supplied by Buzzi, testing their compressive strength and durability. The goal is to halve the CO₂ emissions of traditional concrete mixes.

Chair of the Department of Civil and Environmental Engineering Shamim Pakzad said "I am excited about the expansion of the research portfolio of CEE departments into this area of greener cement, which opens many opportunities for future research and implementation in industry."

The US Department of Energy (DOE) announced a US$1.6bn investment in the cement sector this week. The funding was part of a total of US$6bn for 33 projects in over 20 states to decarbonise energy-intensive industries also including chemicals and refining, iron and steel, aluminium and metals, food and beverages, glass, process heat applications and pulp and paper. The DOE was keen to link the money to “the President’s Bipartisan Infrastructure Law and Inflation Reduction Act.” Politics is never far away it seems! The projects are part of the Industrial Demonstrations Program, managed by DOE’s Office of Clean Energy Demonstrations (OCED).

Table 1: Summary of US Department of Energy funding announced on March 2024 to decarbonise cement and concrete production

Table 1 above shows the main approaches each of the projects aim to use. The two most expensive ones involve carbon capture and sequestration (CCS) at Heidelberg Materials US’ Mitchell cement plant in Indiana and National Cement’s Lebec plant in California respectively. In a complimentary press release Chris Ward, the CEO of Heidelberg Materials North America, said “This substantial federal funding investment will help create the first full-scale deployment of carbon capture and storage on a cement plant in the US.” The proposed CCS unit at the plant will capture around 2Mt/yr of CO₂ from 2030. If Ward’s forecast is accurate (and no one beats them to it), then Heidelberg Materials will likely have set up the first full-scale CCS units at cement plants in both North America and Europe. This will be a significant achievement. The National Cement project, by contrast, is a mixed bag of approaches to decarbonising cement production that follows the multi-lever approach advocated for in many of the industry net-zero roadmaps. It intends to use agricultural by-products such as pistachio shells, as alternatives fuels to lower the fuel-based emissions, calcined clay to lower the clinker factor and CCS to capture the remaining 950,000t/yr of CO₂ emissions.

The other projects either involve using calcined clay or substituting limestone with calcium silicate. The Summit Materials proposal is noteworthy because it aims to build four clay calcination units in locations in Maryland, Georgia and Texas. None of these appear to be near Summit’s (or Cementos Argos’) cement plants. This suggests that the company may be intending to use calcined clay in ready-mixed concrete production. The Roanoke Cement Company calcined clay project will be baseEuropead at its cement plant in Troutville, Virginia.

The remaining two grant recipients, Brimstone and Sublime Systems, will both test the companies’ different methods of manufacturing cement by using calcium silicate instead of limestone. Brimstone’s method produces ordinary Portland cement (OPC) and supplementary cementitious materials (SCM). The company said in July 2023 that its OPC met the ASTM C150 standards. However, the company has released less information about its actual process. Sublime Systems’ uses an electrolysis approach to create its ASTM C1157-compliant cement. It calls this ‘ambient temperature electrochemical calcination.’

Investment on the same scale of the DOE has also been happening in Europe. In July 2023, for example, the European Commission announced an investment of Euro3.6bn in clean tech projects to be funded from the proceeds of the European Union emissions trading scheme (ETS). This was the third call for large-scale projects following previous announcements of recipients in 2021 and 2022. Euro1.6bn of the third call funding went towards cement and refining projects including five cement and lime projects in Belgium, Croatia, Germany and Greece. The money granted for each of these schemes was in the region of Euro115 - 235m.

Both the US and Europe are throwing serious finance at the cement industry to try and kickstart the various pathways towards net zero. They are also doing it in different ways, with the US aiming to boost its economy by onshoring sustainable industry, and Europe hoping to fund its approach via carbon taxation. Government-driven decarbonisation investment for cement in other large countries and regions around the world appears to be lagging behind the US and Europe but these may spring up as net zero targets are set, roadmaps drawn up and government policy formulated. These places could also benefit from watching what works and does not work elsewhere first. Back in the US and Europe the next tricky part of this process will be bridging the gap between government subsidy and commercial viability.

France: Ecocem has launched a new low-carbon advanced cement technology (ACT) cement, aiming for widespread adoption in European construction projects. The ACT range promises a clinker concentration of 20%, lower than the current norm of 35% minimum.

Jean-Christophe Trassard, Director, Marketing of Sustainable Innovation, said "We achieve competitive rates by controlling granularity, the fineness of grinding and admixtures. We have also greatly developed our thinking on the addition of additives in our formulations, which required more than fifteen years of R&D and the filing of six patents."

This product contains locally sourced additives, with the capability to adapt mixes to regional availability. The ACT cement is expected to reduce water usage by one-third compared to conventional concrete. An ACT-based concrete reportedly emits 198kg CO₂/t, a substantial reduction from the 614kg CO₂/t for standard concrete in France.

Gaining market entry for ACT required European technical evaluation and European assessment document certification, currently pending in the EU Official Journal. Trassard added, "As we are dealing with clinker rates below the standards, we had to go through this certification, which gives us a very good passport for the European markets. However, local administrative variations will have to be carried out subsequently."

In France, Ecocem has already applied for ATEX certification to facilitate deployment of the ACT range, expected later in 2024. Ecocem aims to include the ACT range in standard norms by 2026.

US: The US Department of Energy has selected four cement producers to receive funding under the Bipartisan Infrastructure Law and the Inflation Reduction Act.

Heidelberg Materials US secured up to US$500m for its planned 2Mt/yr carbon capture project at the Mitchell cement plant in Indiana. National Cement also received up to US$500m, for its Lebec Net Zero limestone calcined clay cement (LC3) project in California. Summit Materials received up to US$216m for a series of clay calcination projects in Georgia, Maryland and Texas. Lastly, Roanoke Cement will receive up to US$61.7m for an LC3 project at its Troutville cement plant in Virginia.  These projects also involve developing a training, education and certification consortium in the cement sector.

Portland Cement Association (PCA) president and CEO Mike Ireland said "This funding is a welcome acknowledgement from the government that America's cement manufacturers are taking ambitious and significant steps toward reaching carbon neutrality. This will move the needle closer to achieving what industry considers the 'heavyweight' of carbon solutions: carbon capture utilisation and storage (CCUS). Once established nationwide, CCUS will greatly accelerate cement manufacturers' charge toward net zero."

Senior vice president of government affairs Sean O'Neill added “From passage of the Bipartisan Energy Act of 2020 to securing funding through the Inflation Reduction Act and the Infrastructure Investment and Jobs Act, today's announcement is another major milestone in the cement industry's decarbonisation efforts. The PCA is committed to continuing to work with policymakers to ensure the regulatory environment facilitates rather than impedes these and future investments.