Innovation with Graphene:

Towards a More Sustainable and Efficient Cement Industry

Part 1

Carbon dioxide (CO2) is a colorless, odorless, and non-toxic gas naturally present in the atmosphere. Under normal conditions, it should remain balanced to retain the heat necessary for human survival without becoming a greenhouse gas. However, overpopulation, industrialization, and environmental exploitation have disrupted this balance, making CO2 levels increasingly difficult to control. Consequently, these levels rise, concentrate, absorb radiation, and prevent heat from escaping, contributing to global warming.

According to statistics, cement production and the fossil fuel industry (coal, oil, and natural gas) are responsible for releasing about 90% of CO2 and probably 70% of greenhouse gases. Other industries, such as agriculture, fashion, and transportation, also contribute.

“Sustainability of our civilization depends on whether we can provide energy, food, and chemicals to the growing population without compromising the long-term health of our planet.” Doria-Serrano, 2009.

Concerning cement, the main component of concrete, reports mention that it alone accounts for between 7% and 8% of global CO2 emissions. For reference, producing one ton of clinker, the main component of cement, releases approximately ~0.86 tons of CO2, of which around 60% comes from the transformation of limestone into calcium oxide or lime at an average temperature of 1450 °C, a process also known as clinker burning. The remaining 40% is attributed to the combustion of fossil fuel (coal) necessary for the calcination of limestone and clinker formation.

“In 2021, carbon emissions from cement production reached nearly 2,900 million tons of carbon dioxide, while in 2002, 1,400 million tons were recorded.” The Global Carbon Project.

Therefore, to achieve the net-zero emissions target by 2050 required by the Paris Agreement, the cement industry has been forced to take measures to reduce its impact by using alternative fuels (biomass, tires, urban solid waste); improving energy efficiency by reducing the clinkerization temperature through fluxes and mineralizers (such as CaF2, BaO, SnO2, P2O5, Na2O, NiO, ZnO, etc.) or by renewing kilns; modifying cement chemistry with supplementary materials to reduce clinker consumption or capture CO2; and, recently, using graphene to improve the quality of cement and concrete.

“By 2050, global concrete consumption is expected to increase by 12% to 23% from 25 billion per year.”

According to the National Cement Chamber (CANACEM), most projects registered in Latin America are working on replacing fossil fuels with alternative fuels; Mexico is the only country registering higher production of blended cements to reduce clinker content.

Graphene is a nanomaterial consisting of atomic carbon sheets separated from graphite, with mechanical, electrical, thermal, and barrier properties superior to other carbon-based materials, allowing it to venture into countless applications and industries, including construction. According to estimates by Graphene Flagship, the use of graphene in construction is expected to reduce CO2 emissions by 30%.

“The production of 1 kg of graphene produces 0.17 kg of CO2, compared to 0.86 kg of CO2 for Portland cement, reinforcing the nanomaterial’s environmental advantages.”

Since the isolation of graphene in 2004 and the subsequent Nobel Prize in Physics 2010 awarded to its discoverers, an international race began to study, understand, and obtain the nanomaterial in sufficient quantities for large-scale applications at an affordable cost. In the construction sector, it was not until 2018 that research and investments manifested their first results in various parts of the world, such as:

2018: Graphenemex® launched Nanocreto®, the world’s first graphene oxide concrete additive (Mexico).

2019: Graphenenano developed Smart additives, graphene additives for concrete (Spain).

2019: GrapheneCA presented its OG concrete admix product line for the concrete industry (USA).

2021: Scientists at the University of Manchester developed the Concretene concrete additive (UK).

2022: Energeia Fusion-Graphenemex® launched the Graphenergy construction line, an improved version of Nanocreto® (Mexico).

2022: Versarien presented Cementene™, the world’s first 3D-printed construction with a graphene-reinforced mix (UK).

Basquiroto de Souza and collaborators, in their article “Graphene opens pathways to a carbon-neutral cement industry” published in 2022 in Science Bulletin, summarized the opportunities that graphene has for the sustainability of construction materials:

Reduction of Portland cement thanks to significant improvements in compressive strength and elastic modulus of concrete.

Increase the use of by-products or recycled materials in concrete to reduce greenhouse gas emissions by up to 7%, as well as a 2% reduction in energy consumption during the manufacture of graphene oxide reinforced mortar.

Reduction in construction costs due to improved strength or greater incorporation of by-products or waste materials. A cost analysis concluded that while the use of graphene oxide may slightly increase concrete costs, the economy index (compressive strength/cost per m3) of the mixes can increase by up to 40%.

Reduction in maintenance costs. By improving the quality of concrete structures, reductions in CO2 emissions are inferred through a reduction in the amount of construction materials and energy associated with maintenance.

Energy-efficient buildings: graphene’s thermal properties can also be applied to buildings to achieve energy savings by reducing the use of cooling/heating systems.

For Energeia-Graphenemex®, the leading company in Latin America in designing applications with graphene materials, it is a pride to be part of the graphene timeline for sustainable construction.

Authored by: EF/DHS

References

1. Ige, O.E.; Olanrewaju, O.A.; Duffy, K.J.; Collins, O.C. Environmental Impact Analysis of Portland Cement (CEM1) Using the Midpoint Method. Energies 2022, 15, 2708.
2. International Energy Agency, World Business Council for Sustainable Development. Technology roadmap – low-carbon transition in the cement industry. April 2018
3. Felipe Basquiroto de Souza, Xupei Yao, Wenchao Gao, Wenhui Duan, Graphene opens pathways to a carbon-neutral cement industry, Science Bulletin, 2022, 67, 1, 2022, 5
4. Papanikolaou I, Arena N, Al-Tabbaa A. Graphene nanoplatelet reinforced concrete for self-sensing structures– a lifecycle assessment perspective. Journal of Cleaner Production, 2019, 240: 118202
5. Devi S, Khan R. Effect of graphene oxide on mechanical and durability performance of concrete. Journal of Building Engineering, 2020, 27: 101007
6. Doria- Serrano. Química verde: un nuevo enfoque para el cuidado del medio ambiente. Educación química. 2009. UNAM.
7. https://theplanetapp.com/que-son-las-emisiones-de-co2/
8. https://graphene-flagship.eu/materials/news/materials-of-the-future-graphene-and-concrete/#:~:text=Graphene%2Denhanced%20concrete%20is%202.5,CO2%20emissions%20by%2030%25.
9. https://www.versarien.com/files/5716/3050/8952/White_Paper_-_Graphene_for_the_construction_sector_-_final_version.pdf

Graphene Oxide Versatile Applications:

From Sensing Technologies to Environmental Solutions

Graphene and its derivatives such as graphene oxide (GO) and reduced graphene oxide (rGO) are two-dimensional, sheet-like carbon nanomaterials with a wide range of opportunities for numerous applications due to their thinness, transparency, conductivity, flexibility, chemical stability, impermeability, and mechanical strength. In the case of GO and rGO, in addition to their large surface area with hydrophilic and hydrophobic regions inherent to graphene, they allow the adsorption of organic aromatic molecules, ions, and polymers through π-π stacking, hydrogen bonding, and electrostatic interactions. These properties make them suitable materials for constructing sensors or biocatalytic and photocatalytic platforms. According to various reports, the surface-to-volume ratio of graphene materials enhances the surface charge of the desired molecules, while their excellent electrical conductivity, especially at room temperature, favors electron transfer to the surface of electrodes for analysis or photocatalysis.

On the other hand, graphene sheets are not perfectly flat; they exhibit undulations formed as a result of the bonding between their carbon atoms or thermal fluctuations, which can ultimately induce magnetic fields and alter their electronic properties for designing sensors, biosensors, or electronic devices in general. Thus, through more than ten years of research and exploration of their remarkable multifunctionality, the study of graphene has transcended to the development of highly sensitive devices for monitoring, for example, the presence of harmful gases, medically relevant molecules, or proteins, and even water decontamination.

Detection Systems

Metamaterials are a type of compound with the ability to produce useful electromagnetic responses for designing sensors or non-destructive detection devices. Generally, these sensors consist of an insulating material and a conductive material, sensitive to the refractive index of the analyte’s upper layer. In the presence of graphene, it has been observed that this interaction (sensor-analyte) is enhanced by changes in resonance intensity, leading to amplitude changes that further favor detection sensitivity.

In a study conducted in 2023 by the School of Electronic and Information Engineering at Zhejiang University of Science and Technology, Hangzhou, China, a sensor was designed comprising a polyimide (PI) film as an insulating layer, an aluminum structure as a conductive layer, and a monolayer of graphene as the detection interface. Simulation results indicated that graphene could modulate the entire electric field and produce an amplitude change that significantly increases detection limits.

In another study conducted at the Laboratory of Nanostructured Materials of the Institute of Physics at UASLP, functionalized graphene oxide with gold nanoparticles was used as a SERS (Surface Enhanced Raman spectroscopy) biodetection platform, an important technique for biological detection due to its high sensitivity, low sample requirements, relatively low cost, and real-time detection. Crystal violet was used as the standard molecule and flavin adenine dinucleotide as the experimental coenzyme for its participation in numerous redox processes of metabolic reactions and biological electron transport. The results showed that graphene oxide hybrids with gold nanoparticles substantially enhance SERS signals compared to individual nanoparticles. Additionally, the results are consistent with other research on identifying significant improvements for molecule stabilization and fluorescence reduction during measurements, which is often a major drawback of such techniques, supporting its potential as a diagnostic or monitoring tool.

Toxic Gas Removal

Advances in nanoengineering allow graphene and GO sheets to be manipulated for the detection and separation of certain gases. According to the results of a study conducted by the Department of Energy Engineering at Hanyang University, Seoul, Korea, selective diffusion can be achieved by controlling the gas flow channels and pores through different stacking methods, demonstrating that GO’s functional groups provide a unique adsorption behavior towards CO2.

CO2 Conversion

The photocatalytic properties of GO can also be harnessed for converting CO2 into hydrocarbons such as methanol for solar energy capture and CO2 reduction. In 2018, at the Advanced Technology Laboratory for Materials Synthesis and Processing, Wuhan University of Technology, China, silver chromate (Ag2CrO4) nanoparticles were used as a photosensitizer and GO as a co-catalyst for the photocatalytic reduction of CO2 into methanol and methane. The study concluded that this synergy between nanoparticles could enhance conversion activity up to 2.3 times under solar irradiation due to better light absorption, increased CO2 adsorption, and improved charge separation efficiency.

Water Decontamination

Water technologies have various areas of opportunity, particularly in improving filtration or membrane systems. In this regard, it has been found that using hybrid graphene nanostructures, for example, with ruthenium or magnetite, can allow the removal of microorganisms and organic matter present in water. However, research continues to advance to perfect graphene-based methodologies for the removal and reduction of metal ions such as zinc, copper, lead, cadmium, cobalt, among others.

At Energeia-Graphenemex®, we recognize and admire the advancements that research centers have achieved in various areas of knowledge, starting from basic science to applied science results. We firmly believe that in the short or medium term, these technologies will materialize into real products that are useful to society and the environment.

Redaction: EF/ DHS   

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