Hasil untuk "Cement industries"

K. Scrivener, V. John, E. Gartner

Abstract The main conclusions of an analysis of low-CO2, eco-efficient cement-based materials, carried out by a multi-stakeholder working group initiated by the United Nations Environment Program Sustainable Building and Climate Initiative (UNEP-SBCI) are presented, based on the white papers published in this special issue. We believe that Portland-based cement approaches will dominate in the near future due to economies of scale, levels of process optimisation, availability of raw materials and market confidence. Two product-based approaches can deliver substantial additional reductions in their global CO2 emissions, reducing the need for costly investment in carbon capture and storage (CCS) over the next 20–30 years: 1. Increased use of low-CO2 supplements (SCMs) as partial replacements for Portland cement clinker. 2. More efficient use of Portland cement clinker in mortars and concretes. However, other emerging technologies could also play an important role in emissions mitigation in the longer term, and thus merit further investigation.

N. B. Singh, B. Middendorf

Abstract Portland cement manufacture emits 5–7% CO2, which is responsible for global warming. Geopolymers minimize CO2 emission and may be a partial alternative to Portland cement in the building industry. The geopolymer technology gives solution to the utilization of industrial byproducts (waste) containing aluminosilicate phases with little negative impact on environment. Geopolymer cements are mainly produced by using secondary raw materials such as fly ash, metakaolin, calcined clays, zeolite etc. by the activation of alkali/alkali silicate solutions. Combination of different source materials containing aluminosilicate and alkali solutions with optimization of curing temperature, alkali concentrations, additives, Na2O/SiO2 ratio etc. gives geopolymer cements of high mechanical and durability properties. Due to their high mechanical properties and environmental benefit, geopolymer cement and concrete appear as a future prospective construction material and have applications in different areas.

Nabilla Mohamad, K. Muthusamy, R. Embong et al.

Abstract This paper reviews the impact of cement industry towards the global environment and solutions to the problem. The increasing harvesting of raw materials for mounting cement manufacturing causes reduction in quantity of the non-renewable resources such as limestone. The activities linked to harvesting of the resources from natural surroundings, damages the green landscape which is the habitat of flora and fauna exposing to the risk of ecological imbalance. The continuous reaping of these precious resources, exposes it to the risk of depletion in future. Furthermore, the raw materials processing phases in the factory releases dust, noises, greenhouse gases especially carbon dioxide that contaminates the environment and aggravates the climate change. These uninvited environmental issues cause distress to the lifestyle of mankind. Therefore, enhancing the manufacturing technology of cement plant for cleaner production is one of the resolutions to this issue. Approach of using industrial waste as supplementary cementitious material or cement free concrete also would reduce dependency on cement demand. Success in utilizing other alternative material which production consumes lesser natural resources, economic and has lesser harm to the nature to act as binder in concrete would contribute to sustainable and healthier environment for future generation.

E. Benhelal, E. Shamsaei, M. Rashid

Cement industry is an intensive source of fuel consumption and greenhouse gases (GHGs) emissions. This industry is responsible for 5% of GHGs emissions and is among the top industrial sources of carbon dioxide (CO2) emissions. Therefore, CO2 emissions reduction from cement production process has been always an appealing subject for researches in universities and industry. Various efforts have been carried out to mitigate the huge mass of CO2 emissions from the cement industry. Although, majority of these strategies are technically viable, due to various barriers, the level of CO2 mitigation in cement industry is still not satisfactory. Among numerous researches on this topic, only a few have tried to answer why CO2 abatement strategies are not globally practiced yet. This work aims to highlight the challenges and barriers against widespread and effective implementation of CO2 mitigation strategies in the cement industry and to propose practical solutions to overcome such barriers.

Danyang Cheng, David M. Reiner, Fan Yang et al.

Achieving low-carbon development of the cement industry in the developing countries is fundamental to global emissions abatement, considering the local construction industry’s rapid growth. However, there is currently a lack of systematic and accurate accounting and projection of cement emissions in developing countries, which are characterized with lower basic economic country condition. Here, we provide bottom-up quantifications of emissions from global cement production and reveal a regional shift in the main contributors to global cement CO2 emissions. The study further explores cement emissions over 2020-2050 that correspond to different housing and infrastructure conditions and emissions mitigation options for all developing countries except China. We find that cement emissions in developing countries except China will reach 1.4-3.8 Gt in 2050 (depending on different industrialization trajectories), compared to their annual emissions of 0.7 Gt in 2018. The optimal combination of low-carbon measures could contribute to reducing annual emissions by around 65% in 2050 and cumulative emissions by around 48% over 2020-2050. The efficient technological paths towards a low carbon future of cement industry vary among the countries and infrastructure scenarios. Our results are essential to understanding future emissions patterns of the cement industry in the developing countries and can inform policies in the cement sector that contribute to meeting the climate targets set out in the Paris Agreement.

Yangyang Guo, L. Luo, Tingting Liu et al.

Carbon dioxide (CO2) emissions from the cement industry account for 26% of the total industrial emissions, and the need to develop low-carbon techniques within the cement industry is extremely urgent. Low-carbon projects and technologies for the cement industry in different regions and countries have been thoroughly reviewed in this manuscript, and the low-carbon development concept for each county has been analyzed. For developing countries such as China and India, energy saving and efficiency enhancement are currently the key points, while for developed countries and regions such as Europe, more efforts have been focused on carbon capture, utilization, and storage (CCUS). Global CCUS projects have been previously conducted, and the majority of CCUS projects are currently performed in Europe where major projects such as the CEMCAP, CLEANKER, and IEILAC projects represent the latest research progress in cement production technologies and low-carbon technologies for the global cement industry. The development of low-carbon cement technologies has changed from focusing on the end point to instead focusing on the source and process through the exploration of hydrogen and solar energies, and more disruptive and original technologies are expected to be developed, particularly in the cement industry in China.

Osman Gencel, Omer Karadag, Osman Hulusi Oren et al.

Abstract In this review, steel slag usage in the cement and concrete industry and its environmental effects were examined. Also, its physical and chemical structure, its effect on the characteristics of concrete, and its applications in different usage areas were specified. Within the scope of the study, literature was examined by reviewing investigations of steel slag usage in the cement and concrete industry. The content and results of these studies were assessed, and the intended effects of these by-products were presented. These factory by-products, whose storage and release into nature are quite inconvenient, are assessed at different sites around the world and regained to the sector. Thus the benefits of both economic and ecological balance were examined. As a result, opinions and recommendations were presented.

Oluwafemi Ezekiel. Ige, Daramy Vandi Von Kallon, D. Desai

Cement production contributes significantly to anthropogenic greenhouse gas emissions (GHG), a major contributor to global carbon emissions. The environmental impacts of cement production have grown in recent years and it is urgent to reduce its carbon footprint. Systems dynamics (SD) is a simulation method used to understand the nonlinear behavior of complex systems over time. It is commonly used in various sectors to predict emissions and conduct policy experiments. Due to the poor implementation of carbon mitigation strategies within the cement industry, enhancing policymaking by employing more advanced decision-support tools is necessary. This paper reviews previous studies that use the SD approach to assess and compare different mitigation strategies proposed and implemented to reduce carbon emissions in the cement industry. These strategies encompass technological advancements and process improvements, including using alternative fuels and raw materials (adopting low-carbon cementitious materials), energy efficiency improvements, carbon capture and storage and waste heat recovery. The review examines the papers' scope, model descriptions, validation method and mitigation methods highlighted in each study, providing valuable insights for decision makers in the cement industry. Furthermore, the paper discusses the limitations and gaps related to SD modeling, highlighting important factors such as stakeholder engagement in designing effective carbon mitigation strategies. The reviewed studies constantly emphasized technical strategies for mitigating carbon emissions from the cement industry, as stated by the International Energy Agency (IEA) classification. Innovative and emerging technologies, such as WHR, depends on adequate funding, motivation and research and development. However, they frequently neglected to address the barriers hindering their implementation or provide detailed policy measures to overcome them using SD. Additional research is required to assess the practicality and costs of implementing these strategies. Navigating the way to sustainability in the cement industry: Exploring mitigation strategies through systems dynamics model

S. Barbhuiya, Bibhuti Bhusan Das, Dibyendu Adak

The cement industry plays a significant role in global carbon emissions, underscoring the urgent need for measures to transition it toward a net-zero carbon footprint. This paper presents a detailed plan to this end, examining the current state of the cement sector, its carbon output, and the imperative for emission reduction. It delves into various low-CO2 technologies and emerging innovations such as alkali-activated cements, calcium looping, electrification, and bio-inspired materials. Economic and policy factors, including cost assessments and governmental regulations, are considered alongside challenges and potential solutions. Concluding with future prospects, the paper offers recommendations for policymakers, industry players, and researchers, highlighting the roadmap's critical role in achieving a carbon-neutral cement sector.

O. Cavalett, M. Watanabe, M. Voldsund et al.

Cement production is a main source of carbon emissions. Decarbonization options exist, but their climate change mitigation potential, feasibility and environmental implications are still unclear. Here we assess 15 decarbonization options for the European cement industry under current and future conditions. Climate impacts per tonne of clinker produced today in European countries vary between 832 and 1,075 kg CO2-equivalents. Decarbonization options at various maturity levels can mitigate between 7 and 135 Mt CO2-equivalents per year (4–108% of today’s annual emissions from European cement plants), with a range of synergies and trade-offs. Solutions such as alternative fuels or technological improvements reduce climate impacts up to 30%, while a mix of ambitious complementary measures achieves a mitigation of about 50% by 2050. Only rapid and large-scale implementation of carbon capture and storage can approach climate neutrality. Carbon capture for production of e-fuels presents no significant mitigation benefits while it increases other environmental impacts. Cement is a ubiquitous material in modern construction, but produces substantial carbon emissions. Emerging technologies exist that can reduce cement’s carbon footprint, but the right strategies must be implemented ambitiously and synergistically to be effective.

Yutong Jiang, Chenghua Zhang, Kaiwen Feng et al.

Accurate carbon accounting is essential for equitable global carbon trading, particularly in energy-intensive industries. Existing online monitoring systems enable real-time tracking of flue gas parameters but are often hindered by high costs and low accuracy. To address these challenges, this study proposes a carbon emission monitoring method based on the average flow velocity across the flue cross-section. Simulation results indicate that positioning sensors within the central 0.375D to 0.625D region (where D is the flue diameter) minimizes radial velocity deviations and improves measurement uniformity. A customized laboratory platform validated the proposed method, achieving a 5 % average error between measured and actual emissions. Field verification in a cement plant further demonstrated a relative error of 3.58 % compared with the traditional equal-area method. This method significantly reduces the number of required flow sensors while maintaining comparable accuracy, offering a cost-effective and reliable solution for industrial carbon emission monitoring.

Thomas Forbriger, Felix Münch, Laura Hillmann et al.

A rigid connection between the optical fiber and the rock makes amplitudes of 'fiber strain' measured with Distributed Acoustic Sensing (DAS) equal to 'rock strain'. We demonstrate this by running four interrogator units (IU) on a DAS testbed with single-fiber patch cables being cemented into a groove in the concrete floor of Black Forest Observatory (BFO). The recorded signals are compared with the recordings of a calibrated Invar wire strain meter array that has been continuously in operation for the last decades. This way we measure 'strain transfer rate' (ratio of 'fiber strain' over 'rock strain') at frequencies below 0.2 Hz. Waveform similarity for strong earthquake signals is high with typical values of the normalized correlation coefficient greater than 0.95. The 'strain transfer rate' is close to 1 for all four IUs, while it was significantly less in a previous study with DAS cables unreeled on the floor and loaded down by sand and sandbags, only. At frequencies up to 14 Hz we make an intercomparison of IUs, showing no significant variation with frequency. The scatter of 'strain transfer rate' in between channels which are spatially near to each other in the same fiber route is about $\pm$10 % in most cases. The variation of median values in between different IUs and earthquakes is less than 5 %. By subtracting the common mode laser noise, which is coherent along the fiber route, we lower the background signal level to an rms-amplitude of 100 pstrain at 0.1 Hz and 5 pstrain at 1 Hz in a bandwidth of 1/6 decade for the best cases. This allows the detection of the marine microseisms during times of moderate amplitude level.

Elisabeth Van Roijen, Kati Sethares, A. Kendall et al.

Rapid decarbonization of the cement industry is critical to meeting climate goals. Oversimplification of direct air capture benefits from hydrated cement carbonation has skewed the ability to derive decarbonization solutions. Here, we present both global cement carbonation magnitude and its dynamic effect on cumulative radiative forcing. From 1930–2015, models suggest approximately 13.8 billion metric tons (Gt) of CO2 was re-absorbed globally. However, we show that the slow rate of carbonation leads to a climate effect that is approximately 60% smaller than these apparent benefits. Further, we show that on a per kilogram (kg) basis, demolition emissions from crushing concrete at end-of-life could roughly equal the magnitude of carbon-uptake during the demolition phase. We investigate the sensitivity of common decarbonization strategies, such as utilizing supplementary cementitious materials, on the carbonation process and highlight the importance of the timing of emissions release and uptake on influencing cumulative radiative forcing. Given the urgency of determining effective pathways for decarbonizing cement, this work provides a reference for overcoming some flawed interpretations of the benefits of carbonation. The time-dependent effects of cement production emissions and CO2 uptake through carbonation of hydrated cement at a global scale were quantified. The results show the climate benefits of the CO2 uptake by cement are being significantly over-estimated.

Xinhang Xu, Chong-chong Qi, X. Aretxabaleta et al.

Cement hydration is crucial for the strength development of cement-based materials; however, the mechanism that underlies this complex reaction remains poorly understood at the molecular level. An in-depth understanding of cement hydration is required for the development of environmentally friendly cement and consequently the reduction of carbon emissions in the cement industry. Here, we use molecular dynamics simulations with a reactive force field to investigate the initial hydration processes of tricalcium silicate (C3S) and dicalcium silicate (C2S) up to 40 ns. Our simulations provide theoretical support for the rapid initial hydration of C3S compared to C2S at the molecular level. The dissolution pathways of calcium ions in C3S and C2S are revealed, showing that, two dissolution processes are required for the complete dissolution of calcium ions in C3S. Our findings promote the understanding of the calcium dissolution stage and serve as a valuable reference for the investigation of the initial cement hydration. Despite being crucial for elucidating the cement hydration mechanism, the initial hydration stage is poorly understood. Here, authors uncover the unbiased Ca dissolution pathway during the initial hydration of calcium silicates via atomistic simulations and reveal a key Ca ligand structure.

J. Mañosa, A. Calderón, R. Salgado-Pizarro et al.

Limestone calcined clay cement (LC3) is a recently developed binder with huge potential to reduce the clinker factor in cement and the environmental impact. This study aimed to evaluate the evolution of the research on LC3 by conducting a bibliometric analysis, evaluating key metrics such as publications, authorships, sources, or countries, to provide greater knowledge and a strategic vision of this technology. This work provides an important perspective of the field and elucidates the research trends and path that the LC3 technology followed from its beginning to date. The analysis reveals a noticeable increase in technology readiness and researchers' interest, as indicated by a significant rise in publications' number over time. Also, the authorship metrics reveal an important cooperation between communities in the development of this technology. The research on LC3 is essential since the technology is a viable and reliable approach to decreasing the cement industry's carbon footprint.

Isabel Pol Segura, Navid Ranjbar, Anne Juul Damø et al.

A growing interest in alternative cements has emerged with the sole purpose of reducing the environmental footprint associated with cement production. One of the promising alternatives is to use non-carbonate materials such as alkali-activated materials. They have demonstrated to have a similar performance as traditional Portland cement and have the potential to significantly reduce CO2 emissions. This paper reviews the main relevant technologies that are already available in the construction industry and explains how to consider them for alkali-activated cement and concrete production. This includes aluminosilicate pre-treatment methods (drying, grinding, and calcining) to increase the precursor's reactivity and degree of amorphization, alkali activation by two-part or one-part mix, as well as, mixing and casting fresh alkali-activated concrete ensuring low porosity and adequate strength development. This review also presents an overview of the alkali-activated cements market, providing examples of commercialized products, estimating related CO2 and costs, as well as future considerations for standardization and commercialization. Most of the commercialized alkali-activated materials are two-part mixes despite their limitations for in-situ applications. CO2 emissions can be reduced by more than 68% when compared to Portland cements. However, they have been estimated to be 2 to 3 times more expensive and the cost is primarily dependent on the aluminosilicate and alkali activators source.

Songbin Wu, Zi Shao, R. Andrew et al.

The majority of the carbon footprint of the cement industry originates from the decomposition of alkaline carbonates during clinker production. Recent studies have demonstrated that calcium oxides and other alkaline oxides in cement materials can sequester CO2 through the carbonation process and partially offset the carbon emissions generated during cement production. This study employs a comprehensive analytical model to estimate the CO2 uptake via hydrated cement carbonation, including concrete, mortar, construction waste, and cement kiln dust (CKD), covering major cement production and consumption regions worldwide from 1930 to 2023. In 2023, the global annual cement CO2 uptake reached 0.93 Gt/yr (95% CI: 0.80–1.13Gt/yr). From 1930 to 2023, the global cumulative cement CO2 absorption reached 23.89 Gt (95% CI: 20.47–28.74 Gt), equivalent to 52.32% of the CO2 process emissions from cement production during the same period. Our system for estimating cement emissions and uptake is updated annually, providing consistent and accurate data for the cement industry and carbon cycle studies. This data supports improved adaptation to future challenges.

JaeMyung Lee, BooMee Park

Of the 37% of carbon dioxide emissions generated by the construction industry, 5–7% comes from cement processing. In response to this problem, ways to utilize soil, a material with low energy consumption, are being explored as an eco-friendly option. In particular, eco-friendly design is being emphasized in the construction field through 3D printing technology. The research method proceeds in two stages. The first measures the changes in drying shrinkage, volume mass, compressive strength, and flexural strength over 7 days for a test specimen created by mixing coffee, charcoal, and rice bran with Hwangto. In the second step, slaked lime, a solidifying material, is mixed and tested under the same test specimen conditions as in the first. As a result of the experiment, the higher the mixing ratio of Hwangto, the greater the compressive strength and flexural strength. In particular, coffee exhibited the highest compressive strength at 1.50MPa, while charcoal demonstrated the highest flexural strength at 0.51MPa. However, when solidifying materials were mixed, the overall strength decreased, especially in the case of coffee (1.50MPa for the first time/0.87MPa for the second time), which showed a 42% decrease. Overall, charcoal was the most suitable mixing material and exhibited consistent and stable strength values in all experiments. Based on these experimental results, a 1/50 scale pavilion was produced through 3D printing. The stable shape and appropriate strength of the result were confirmed, making it suitable for educational or practical purposes. It suggests the possibility of use across industries.

Bakhtiar Javaheri, Seyed Meysam Mousavi Fatah, Khaled Ahmadzadeh

Objective In recent years, the increasing demand for energy has highlighted the importance of energy in production. As a strategic energy source, natural gas is a vital component of the production process for goods and services. On the other hand, financial markets are crucial to any country's economy, and stock exchanges are a key component of these markets. Various indices calculated on stock exchanges indicate the return and overall trend of stock prices in the entire market and specific industries. The fluctuation of each index is influenced by changes in the stock prices of companies included in the calculation. Many factors contribute to fluctuations in companies' stock prices, including the price of natural gas, which is used by various industries in their production processes. Changes in gas prices affect companies' profit margins, leading to changes in their stock prices. Ultimately, these changes impact the overall return of the capital market. Given the significance of this topic, this research examines the short-term and long-term effects of changes in natural gas prices on the return of the Iranian stock market.   Methods This research is classified as applied research, employing quantitative methodology. To analyze the monthly data spanning from April 2009 to March 2022, this study utilized the Vector Autoregression (VAR) method and the Johansen Cointegration Test.   Results The results confirm a long-term relationship between natural gas price changes and selected capital market indices. The Johansen Cointegration Test indicates that changes in gas prices have a negative impact on stock market indices, OTC, chemical industries, industry, cement, and petroleum products in both the short- and long-term. Furthermore, the results indicate that exchange rate changes have a positive and significant effect on capital market indices in both the short- and long-term. Finally, the test results show that oil price changes have a negative impact on indices in the short-term, but in the long-term, changes in indices will move in the same direction as oil price changes.   Conclusion Considering the significant impact of gas prices on capital market fluctuations, it is recommended that the government regulate gas prices to minimize their negative effects on capital market indices. To achieve this, sudden decisions regarding gas prices should be avoided. Instead of making annual budget decisions, a dynamic gas pricing formula should be designed, allowing the price of gas offered to industries to fluctuate in response to global gas price changes. This would provide investors with the stable, long-term economic conditions they require. To promote diversification of energy consumption, the government can implement policies to increase investment in renewable and emerging energy sectors, encouraging companies to switch to alternative energy sources. This would reduce industries' dependence on gas and mitigate the impact of gas price changes on the stock market. Objective In recent years, the increasing demand for energy has highlighted the importance of energy in production. As a strategic energy source, natural gas is a vital component of the production process for goods and services. On the other hand, financial markets are crucial to any country's economy, and stock exchanges are a key component of these markets. Various indices calculated on stock exchanges indicate the return and overall trend of stock prices in the entire market and specific industries. The fluctuation of each index is influenced by changes in the stock prices of companies included in the calculation. Many factors contribute to fluctuations in companies' stock prices, including the price of natural gas, which is used by various industries in their production processes. Changes in gas prices affect companies' profit margins, leading to changes in their stock prices. Ultimately, these changes impact the overall return of the capital market. Given the significance of this topic, this research examines the short-term and long-term effects of changes in natural gas prices on the return of the Iranian stock market.   Methods This research is classified as applied research, employing quantitative methodology. To analyze the monthly data spanning from April 2009 to March 2022, this study utilized the Vector Autoregression (VAR) method and the Johansen Cointegration Test.   Results The results confirm a long-term relationship between natural gas price changes and selected capital market indices. The Johansen Cointegration Test indicates that changes in gas prices have a negative impact on stock market indices, OTC, chemical industries, industry, cement, and petroleum products in both the short- and long-term. Furthermore, the results indicate that exchange rate changes have a positive and significant effect on capital market indices in both the short- and long-term. Finally, the test results show that oil price changes have a negative impact on indices in the short-term, but in the long-term, changes in indices will move in the same direction as oil price changes.   Conclusion Considering the significant impact of gas prices on capital market fluctuations, it is recommended that the government regulate gas prices to minimize their negative effects on capital market indices. To achieve this, sudden decisions regarding gas prices should be avoided. Instead of making annual budget decisions, a dynamic gas pricing formula should be designed, allowing the price of gas offered to industries to fluctuate in response to global gas price changes. This would provide investors with the stable, long-term economic conditions they require. To promote diversification of energy consumption, the government can implement policies to increase investment in renewable and emerging energy sectors, encouraging companies to switch to alternative energy sources. This would reduce industries' dependence on gas and mitigate the impact of gas price changes on the stock market.

Giovanni De Gasperis, Sante Dino Facchini

Industrial monitoring systems, especially when deployed in Industry 4.0 environments, are experiencing a shift in paradigm from traditional rule-based architectures to data-driven approaches leveraging machine learning and artificial intelligence. This study presents a comparison between these two methodologies, analyzing their respective strengths, limitations, and application scenarios, and proposes a basic framework to evaluate their key properties. Rule-based systems offer high interpretability, deterministic behavior, and ease of implementation in stable environments, making them ideal for regulated industries and safety-critical applications. However, they face challenges with scalability, adaptability, and performance in complex or evolving contexts. Conversely, data-driven systems excel in detecting hidden anomalies, enabling predictive maintenance and dynamic adaptation to new conditions. Despite their high accuracy, these models face challenges related to data availability, explainability, and integration complexity. The paper suggests hybrid solutions as a possible promising direction, combining the transparency of rule-based logic with the analytical power of machine learning. Our hypothesis is that the future of industrial monitoring lies in intelligent, synergic systems that leverage both expert knowledge and data-driven insights. This dual approach enhances resilience, operational efficiency, and trust, paving the way for smarter and more flexible industrial environments.