Hasil untuk "Cement industries"

Ankur Mehta, Deepankar Kumar Ashish

Abstract The vast emission of greenhouse gases from industrial wastes is a global problem. The non-biodegradable nature of industrial wastes like silica fume, glass, bottom ash, and rubber tyres increases the severity of the problem. Past studies suggest that the use of waste materials in the cement and construction industry could be a viable solution to prevent natural resources from extinction. The chemical composition of silica fume and waste glass are attracting cement and concrete industries as a sustainable solution. In recent years, green concrete is very popular among researchers and academicians, but green concrete is still at an early stage. This paper studies the influence of silica fume and waste glass on the workability, strength, and durability properties of concrete. Moreover, the microstructural analysis was also studied.

Sabbie A. Miller, G. Habert, R. Myers et al.

Summary Cement is used globally in construction materials for nearly all civil infrastructure systems supporting improved quality of life, and there is currently no substitute that can meet its functional capacity. The magnitude of cement production leads to more than 7% of annual anthropogenic greenhouse gas (GHG) emissions, resulting from both energy use and chemical reactions, which imposes a notable barrier to reach net zero emissions by 2050. This barrier is exacerbated by the interconnectivity of industries responsible for cement consumption. Here, we articulate current emission reduction challenges facing industries responsible for the production and use of cement and its products, and propose a compilation of solutions that focus on mitigating emissions from cement production at various stages along its value chain. We present frameworks for design within a circular economy and for policy decisions. We anticipate that these strategies can deliver cement production with zero GHG emissions and alleviate other environmental impacts.

Hessam Golmohamadi

The penetration of renewable energies is increasing in power systems all over the world. The volatility and intermittency of renewable energies pose real challenges to energy systems. To overcome the problem, demand-side flexibility is a practical solution in all demand sectors, including residential, commercial, agricultural, and industrial sectors. This paper provides a comprehensive review of industrial demand response opportunities in energy-intensive industries. Flexibility potentials are discussed from (1) viewpoints of power flexibility for cement manufacturing and aluminum smelting plants (2) viewpoints of joint power-heat flexibility for oil refinery industries. The flexibility potentials of industrial processes are classified based on their compatibility with time responses on long, mid, and short advance notices of different electricity market floors and ancillary service markets. Challenges and opportunities of industrial demand management are classified from viewpoints of power systems and industry owners. Software tools and solution methodologies of industrial energy models are surveyed for energy researchers. The studies show that cement manufacturing plants have great potentials in providing peak-shaving and valley-filling in crushers and cement mills with up to 10% and 16.9% reduction in energy consumption cost and power consumption, respectively. The aluminum smelting plants can provide up to 34.2% and 20.70% reduction in energy consumption cost and power consumption by turning down/off the variable voltage smelting pots.

P. V. Nidheesh, M. Kumar

Abstract Eco-friendly industrial production is essential to save our environment. The present article reviews the sustainability aspects for steel and cement industries, as both are highly demanding. Carbon dioxide emissions from the steel industry can be reduced effectively by carbon sequestration methods. The generation of by-products from steel can be used as raw materials in manufacturing of paints, cement fertilizers etc. The major challenge in cement production is higher input of raw material and fuel in clinker production. These problems can be rectified by adopting suitable co-processing method. Energy requirement can be reduced by using blended cement with highly efficient clinker cooler, dryer, separators, calciner, pre-calciner and waste heat recovery system.

Bahiru Bewket Mitikie, Demelash Leyekun Kebede, Walied A. Elsaigh

Cement is a critical construction material globally and particularly in Ethiopia, where its production is energy-intensive, costly, and a major source of greenhouse gas emissions. This study explores the partial replacement of Portland cement with volcanic ash and crushed laterite powder in cement mortar as a sustainable and cost-effective alternative. Preliminary mix designs were prepared with varying proportions of volcanic ash and laterite powder to determine optimal combinations which is equal percentage of volcanic ash and laterite powder as selected based the compressive strength result. Subsequent experimental mixes replaced cement with equal proportion of volcanic ash and laterite soil at 0%, 5%, 10%, 15%, 20%, 25%, and 30% by weight, following ASTM C109 standards. The study assessed characterization, mechanical (compressive strength and ultrasonic pulse velocity), durability (sulfate resistance, porosity, and water absorption), and microstructural properties using Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), and differential thermal analysis (DTA) analyses. Characterization results showed that volcanic ash and crushed laterite are finer than cement and are predominantly pozzolanic. Bernauer-Emmett-Teller (BET) analysis confirmed their fine particle sizes, contributing to the dense packing of the mortar. At 10% of replacement of cement by equal amount of volcanic ash and laterite soil, the highest compressive strength was recorded 33.1 MPa at 28 days and 46.2 MPa at 56 days. Water absorption decreased with increasing the replacement percentage up to 15%, indicating improved durability. Microstructural analysis revealed a denser morphology due to secondary C-S-H formation and filler effects. Overall, volcanic ash and laterite powder improved both mechanical and durability properties of mortar up to 15% replacement, with optimal performance at 10%. This shows the potential of those pozzolanic as a viable partial cement substitute, promoting sustainable construction practices in Ethiopia.

Nataliya Tkachenko, Kevin Tang, Matthew McCarten et al.

Cement producers and their investors are navigating evolving risks and opportunities as the sector’s climate and sustainability implications become more prominent. While many companies now disclose greenhouse gas emissions, the majority from carbon-intensive industries appear to delegate emissions to less efficient suppliers. Recognizing this, we underscore the necessity for a globally consolidated asset-level dataset, which acknowledges production inputs provenance. Our approach not only consolidates data from established sources like development banks and governments but innovatively integrates the age of plants and the sourcing patterns of raw materials as two foundational variables of the asset-level data. These variables are instrumental in modeling cement production utilization rates, which in turn, critically influence a company’s greenhouse emissions. Our method successfully combines geospatial computer vision and Large Language Modelling techniques to ensure a comprehensive and holistic understanding of global cement production dynamics.

Manvendra Verma, Nirendra Dev, I. Rahman et al.

Geopolymer concrete (GPC) is a new material in the construction industry, with different chemical compositions and reactions involved in a binding material. The pozzolanic materials (industrial waste like fly ash, ground granulated blast furnace slag (GGBFS), and rice husk ash), which contain high silica and alumina, work as binding materials in the mix. Geopolymer concrete is economical, low energy consumption, thermally stable, easily workable, eco-friendly, cementless, and durable. GPC reduces carbon footprints by using industrial solid waste like slag, fly ash, and rice husk ash. Around one tonne of carbon dioxide emissions produced one tonne of cement that directly polluted the environment and increased the world’s temperature by increasing greenhouse gas production. For sustainable construction, GPC reduces the use of cement and finds the alternative of cement for the material’s binding property. So, the geopolymer concrete is an alternative to Portland cement concrete and it is a potential material having large commercial value and for sustainable development in Indian construction industries. The comprehensive survey of the literature shows that geopolymer concrete is a perfect alternative to Portland cement concrete because it has better physical, mechanical, and durable properties. Geopolymer concrete is highly resistant to acid, sulphate, and salt attack. Geopolymer concrete plays a vital role in the construction industry through its use in bridge construction, high-rise buildings, highways, tunnels, dams, and hydraulic structures, because of its high performance. It can be concluded from the review that sustainable development is achieved by employing geopolymers in Indian construction industries, because it results in lower CO2 emissions, optimum utilization of natural resources, utilization of waste materials, is more cost-effective in long life infrastructure construction, and, socially, in financial benefits and employment generation.

Katrin E. Daehn, R. Basuhi, J. Gregory et al.

Martin Chaigne, Sébastien Manneville, Michael Haist et al.

Cement paste serves as the universal binder in concrete, formed by mixing water with Ordinary Portland Cement (OPC). In its fresh state, cement paste is a suspension in which the initial particle inventory continuously dissolves, while simultaneously, a growing population of colloidal calcium silica-hydrate (C-S-H) particles forms and progressively builds a percolated structure that densifies and hardens through hydration. Like most colloidal gels, cement paste is sensitive to external stimuli such as mechanical vibrations and temperature variations. Here, we show that power ultrasound (PUS) applied to OPC paste during the very early stages of hydration significantly alters the mechanical properties of the hardened material. Freshly prepared cement pastes are exposed to PUS at varying durations and intensities before curing for 28 days. Micro-indentation testing at the scale of tens of microns reveals that increasing PUS amplitude and prolonged PUS exposure degrade the micro-mechanical properties of hardened cement paste, making it more ductile. This softening behavior evolves continuously with exposure conditions and is consistent with an increase in porosity, likely caused by micro-cracks induced by PUS. This scenario is further supported by micro-scratch testing, which shows higher levels of acoustic emission in PUS-exposed samples. Finally, nano-indentation confirms that the properties of the individual phases composing the hardened paste -- low-density and high-density C-S-H -- remain largely unaffected. These findings offer valuable experimental insights into novel pathways for modifying the mechanical properties of reactive colloidal gels.

Luca Michel, Antoine Sanner, Franco Zunino et al.

The early stiffening of fresh cement paste plays a key role in shaping and stability during casting and 3D printing. In Portland cement systems, this phenomenon arises from the formation of calcium-silicate-hydrate (C-S-H), which stiffens grain-to-grain contacts. However, the role of powder characteristics such as particle size and morphology remains poorly understood. Here, we vary the fineness and grain shape by blending Portland cement with either coarse or fine limestone, leveraging the affinity of C-S-H to nucleate on limestone surfaces. By coupling calorimetry and rheometry, we relate the amount of formed hydration products to the increase in stiffness, and show that the mechanism of contact stiffening through C-S-H formation remains unchanged with limestone addition. Nevertheless, the rate of stiffening varies across blends. We find that these rates correlate with a characteristic length scale that captures particle size and shape. These results demonstrate that early stiffening depends not only on the amount of hydration products formed, but also on the geometry of the contacts where these products form, offering a framework for understanding more complex systems such as limestone-calcined clay cements.

Melanie Schaller, Sergej Hloch, Akash Nag et al.

This study investigates a pulsating fluid jet as a novel precise, minimally invasive and cold technique for bone cement removal. We utilize the pulsating fluid jet device to remove bone cement from samples designed to mimic clinical conditions. The effectiveness of long nozzles was tested to enable minimally invasive procedures. Audio signal monitoring, complemented by the State Space Model (SSM) S4D-Bio, was employed to optimize the fluid jet parameters dynamically, addressing challenges like visibility obstruction from splashing. Within our experiments, we generate a comprehensive dataset correlating various process parameters and their equivalent audio signals to material erosion. The use of SSMs yields precise control over the predictive erosion process, achieving 98.93 \% accuracy. The study demonstrates on the one hand, that the pulsating fluid jet device, coupled with advanced audio monitoring techniques, is a highly effective tool for precise bone cement removal. On the other hand, this study presents the first application of SSMs in biomedical surgery technology, marking a significant advancement in the application. This research significantly advances biomedical engineering by integrating machine learning combined with pulsating fluid jet as surgical technology, offering a novel, minimally invasive, cold and adaptive approach for bone cement removal in orthopedic applications.

Anissa Nurdiawati, F. Urban

Industries account for about 30% of total final energy consumption worldwide and about 20% of global CO2 emissions. While transitions towards renewable energy have occurred in many parts of the world in the energy sectors, the industrial sectors have been lagging behind. Decarbonising the energy-intensive industrial sectors is however important for mitigating emissions leading to climate change. This paper analyses various technological trajectories and key policies for decarbonising energy-intensive industries: steel, mining and minerals, cement, pulp and paper and refinery. Electrification, fuel switching to low carbon fuels together with technological breakthroughs such as fossil-free steel production and CCS are required to bring emissions from energy-intensive industry down to net-zero. A long-term credible carbon price, support for technological development in various parts of the innovation chain, policies for creating markets for low-carbon materials and the right condition for electrification and increased use of biofuels will be essential for a successful transition towards carbon neutrality. The study focuses on Sweden as a reference case, as it is one of the most advanced countries in the decarbonisation of industries. The paper concludes that it may be technically feasible to deep decarbonise energy-intensive industries by 2045, given financial and political support.

T. Watari, A. Cabrera Serrenho, Lukas Gast et al.

The current decarbonization strategy for the steel and cement industries is inherently dependent on the build-out of infrastructure, including for CO2 transport and storage, renewable electricity, and green hydrogen. However, the deployment of this infrastructure entails considerable uncertainty. Here we explore the global feasible supply of steel and cement within Paris-compliant carbon budgets, explicitly considering uncertainties in the deployment of infrastructure. Our scenario analysis reveals that despite substantial growth in recycling- and hydrogen-based production, the feasible steel supply will only meet 58–65% (interquartile range) of the expected baseline demand in 2050. Cement supply is even more uncertain due to limited mitigation options, meeting only 22–56% (interquartile range) of the expected baseline demand in 2050. These findings pose a two-fold challenge for decarbonizing the steel and cement industries: on the one hand, governments need to expand essential infrastructure rapidly; on the other hand, industries need to prepare for the risk of deployment failures, rather than solely waiting for large-scale infrastructure to emerge. Our feasible supply scenarios provide compelling evidence of the urgency of demand-side actions and establish benchmarks for the required level of resource efficiency.

Yu Wang, Honghong Yi, Xiaolong Tang et al.

The cement industry is one of the most energy- and carbon-intensive industries in China, and it is difficult to attain deep decarbonization toward carbon neutrality. This paper provides a comprehensive review of the historical emission trend and future decarbonization pathway of China's cement industry, in which the opportunities and challenges of key technologies, carbon mitigation potential and co-benefits are examined. The results showed that from 1990 to 2020, the carbon dioxide (CO2) emissions of China's cement industry experienced a growing trend, while air pollutant emissions were largely decoupled from cement production growth. Between 2020 and 2050, China's cement production may decrease by over 40 %, and CO2 emissions will decline from 1331 Tg to 387 Tg under the Low scenario given a combination of certain mitigation measures, including energy efficiency improvement, alternative energy sources, alternative materials, carbon capture, utilization, and storage (CCUS) technology, and new cement. Before 2030, carbon reduction under the low scenario is determined by factors including energy efficiency improvement, alternative energy sources, and alternative materials. Afterward, CCUS technology will become increasingly imperative and conducive to deep decarbonization of the cement industry. After implementation of all the above measures, 387 Tg of CO2 will still be emitted by the cement industry in 2050. As such, improving the quality and service life of buildings and infrastructure as well as the carbonation of cement materials has a positive effect on carbon reduction. Finally, carbon mitigation measures in the cement industry can provide air quality improvement co-benefits.

L. Nilsson, Fredric Bauer, Max Åhman et al.

ABSTRACT The target of zero emissions sets a new standard for industry and industrial policy. Industrial policy in the twenty-first century must aim to achieve zero emissions in the energy and emissions intensive industries. Sectors such as steel, cement, and chemicals have so far largely been sheltered from the effects of climate policy. A major shift is needed, from contemporary industrial policy that mainly protects industry to policy strategies that transform the industry. For this purpose, we draw on a wide range of literatures including engineering, economics, policy, governance, and innovation studies to propose a comprehensive industrial policy framework. The policy framework relies on six pillars: directionality, knowledge creation and innovation, creating and reshaping markets, building capacity for governance and change, international coherence, and sensitivity to socio-economic implications of phase-outs. Complementary solutions relying on technological, organizational, and behavioural change must be pursued in parallel and throughout whole value chains. Current policy is limited to supporting mainly some options, e.g. energy efficiency and recycling, with some regions also adopting carbon pricing, although most often exempting the energy and emissions intensive industries. An extended range of options, such as demand management, materials efficiency, and electrification, must also be pursued to reach zero emissions. New policy research and evaluation approaches are needed to support and assess progress as these industries have hitherto largely been overlooked in domestic climate policy as well as international negotiations. Key policy insights Energy and emission intensive industries can no longer be complacent about the necessity of zero greenhouse gas (GHG) emissions. Zero emissions require profound technology and organizational changes across whole material value chains, from primary production to reduced demand, recycling and end-of-life of metals, cement, plastics, and other materials. New climate and industrial policies are necessary to transform basic materials industries, which are so far relatively sheltered from climate mitigation. It is important to complement technology R&D with the reshaping of markets and strengthened governance capacities in this emerging policy domain. Industrial transformation can be expected to take centre stage in future international climate policy and negotiations.

Nitin Ankur, Navdeep Singh

Shashank Gupta, Reza Moini

Cortical bone is a tough biological material composed of tube-like osteons embedded in the organic matrix surrounded by weak interfaces known as cement lines. The cement lines provide a microstructurally preferable crack path, hence triggering in-plane crack deflection around osteons due to cement line-crack interaction. Here, inspired by this toughening mechanism and facilitated by a hybrid (3D-printing/casting) process, we engineer architected tubular cement-based materials with a new stepwise cracking toughening mechanism, that enabled a non-brittle fracture. Using experimental and theoretical approaches, we demonstrate the underlying competition between tube size and shape on the stress intensity factor from which engineering stepwise cracking can emerge. Two competing mechanisms, both positively and negatively affected by the growing tube size, arise to significantly enhance the overall fracture toughness by up to 5.6-fold compared to the monolithic brittle counterpart without sacrificing the specific strength. This is enabled by crack-tube interaction and engineering the tube size and shape, which leads to stepwise cracking and promotes rising R-curves. Disorder curves are proposed for the first time to quantitatively characterize the degree of disorder for describing the representation of architected arrangement of materials (using statistical mechanics parameters) in lieu of otherwise inadequate periodicity classification.

Jan Lorenz Svensen, Wilson Ricardo Leal da Silva, Javier Pigazo Merino et al.

This study provides a systematic description and results of a dynamical simulation model of a rotary kiln for clinker, based on first engineering principles. The model is built upon thermophysical, chemical, and transportation models for both the formation of clinker phases and fuel combustion in the kiln. The model is presented as a 1D model with counter-flow between gas and clinker phases and is demonstrated by a simulation using industrially relevant input. An advantage of the proposed model is that it provides the evolution of the individual compounds for both the fuel and clinker. As such, the model comprises a stepping stone for evaluating the development of process control systems for existing cement plants.

Jan Lorenz Svensen, Nicola Cantisani, Wilson Ricardo Leal da Silva et al.

We provide a cyclone model for dynamical simulations in the pyro-process of cement production. The model is given as an index-1 differential-algebraic equation (DAE) model based on first engineering principle. Using a systematic approach, the model integrates cyclone geometry, thermo-physical aspects, stoichiometry and kinetics, mass and energy balances, and algebraic equations for volume and internal energy. The paper provides simulation results that fit expected dynamics. The cyclone model is part of an overall model for dynamical simulations of the pyro-process in a cement plant. This model can be used in the design of control and optimization systems to improve energy efficiency and reduce CO2 emission.

E. T. Stepkowska, J. L. Pérez Rodríguez, M. J. Sayagués et al.

Cement hydration products were studied as influenced by the hydration conditions (hydration time in liquid phase; relative humidity, RH, in gaseous phase). The formation of calcium hydroxide (portlandite, P) and its transformation to calcium carbonates is mainly discussed here.