Energy-intensive industries play a critical role in achieving carbon reduction goals. This paper proposes a quantitative evaluation model for Marginal Abatement Costs (MACs) and carbon reduction potential, enabling scientific assessment of abatement costs and capabilities. Building on this model, a comprehensive assessment framework is further introduced, integrating both economic and environmental dimensions through novel indicators such as the baseline MAC and the carbon reduction index. Using 2022 data on carbon reduction technologies and industrial carbon emissions from China’s steel, cement, petrochemical, power, and coal industries, an empirical analysis is conducted. The results reveal clear differences in abatement capabilities across industries, offering valuable insights for developing targeted low-carbon transition strategies in energy-intensive industries.
Excavated soil from construction and demolition activities can be stabilized by alkali-activated binders to manufacture low-carbon construction materials. This research attempts to investigate the efficacy of non-sonicated (S) and sonicated sucrose (USS) as a controlled retarder in alkali-activated materials containing excavated lateritic soil (EAAM) (clay content of 42.5 %). Influences of sucrose dosage and sonication on hydration kinetics, setting, and structural build-up of EAAM have been investigated. Findings from isothermal calorimetry show 30 – 65 % retardation in hydration kinetics leading to a 50 – 60 % delay in setting and slower structural build-up of EAAM during the initial 12 h. This results in higher flowability and superior flow retention for longer duration than the control (0 % sucrose). By decoupling the effect on hydration of GGBS and FA, it is found that sucrose has a more dominant retarding effect on GGBS compared to FA, attributed to its stronger interaction with calcium-rich sites than aluminates. The addition of 2 % USS to EAAM results in higher retardation compared to 2 %S. This is attributed to the formation of acidic byproducts due to sonication-induced breakdown of sucrose molecules, leading to reduced pH and electrostatic repulsion. The densified microstructure of EAAM with USS compared to that with S results in a noticeable improvement in strength retention under wet conditions, suggesting reduced moisture sensitivity. Due to enhanced hydration at later ages, sucrose-EAAM possesses 30 – 48 % higher wet compressive strength than the control EAAM at the 28-day mark. Overall, sucrose, which can be prepared from waste biomass through “green” processes, can be a potential chemical admixture for earth-based alkali-activated constructions.
Industries are significant contributors to global energy consumption and greenhouse gas emissions, making energy efficiency improvements essential. WHR offers a valuable solution by capturing and reusing heat that would otherwise be lost, thus enhancing energy efficiency and reducing environmental impacts. This paper explores the application of WHR technologies across various industries, including steel, cement, and petrochemicals, where waste heat accounts for a large portion of energy losses. Technologies such as heat exchangers, ORC, and TEGs are discussed for their roles in converting waste heat into usable energy forms, such as electricity or heat for industrial processes. The review also covers advancements in materials and hybrid systems to optimize efficiency, as well as the potential of WHR in stabilizing renewable energy sources like solar and wind power. The integration of WHR systems into smart grids is highlighted as a future trend for improving energy management.
Concrete sleepers worldwide have been affected by internal swelling reactions (ISR), primarily alkali-silica reaction (ASR) and internal sulfate attack (ISA). While numerous studies have focused on diagnosing ISR-affected sleepers, most emphasize identifying the cause rather than estimating the extent of deterioration, which is critical for informed decision-making. This study presents a comprehensive condition assessment of concrete sleepers displaying numerous ages and environmental exposure conditions through visual inspection (i.e., crack measurements) followed by the implementation of the multi-level assessment protocol, composed of microscopic (i.e., damage rating index-DRI) and mechanical (i.e., stiffness damage test-SDT) testing procedures. Results evidenced the multi-level protocol efficiency in estimating the cause(s) (i.e., ASR+ISA), further confirmed through SEM-EDS analysis, and quantifying the deterioration extent. These findings reveal gaps in current specification to prevent ISR damage in new sleepers and the importance of considering environmental conditions in condition assessment of existing sleepers, demonstrating an urgent need to review specifications/protocols.
Muhammad Nasir, Ashraf A. Bahraq, Rida Assaggaf
et al.
Abstract The lack of periodic safe disposal of silico-manganese wastes poses significant environmental and health risks. Producing each ton of silico-manganese alloy results in more than one ton of slag and 10%–15% fume, which can supplement cement in concrete. This study presents the first critical review of silicomanganese fume (SiMnF) for the synthesis of cementitious composites and evaluation of engineering properties. The review covers the fresh, hardened, and durability characteristics, along with the microstructural development of SiMnF-based Portland cement and alkali-activated products. It also examines the synergistic effects of SiMnF with other supplementary cementitious materials, focusing on rheological and mechanical aspects. The findings indicate that pre-treatment of raw materials and post-treatment of composites are essential for achieving target properties. Optimized dosage of SiMnF, alkaline activator concentration, and curing conditions can provide workable mixes with compressive strengths of up to 50 MPa. A detailed life-cycle assessment was conducted to quantify the environmental impact of SiMnF-based mixtures. Based on identified knowledge gaps, the study proposes a roadmap for future research. This review highlights the strategies for SiMnF from ferroalloy plants to be used in the cement and concrete industries, promoting solid waste management, reducing carbon footprints, and supporting sustainable development towards net-zero emission targets.
Materials of engineering and construction. Mechanics of materials, Environmental engineering
Bahiru Bewket Mitikie, Teshome Anteneh Wubetie, Walied A. Elsaigh
Abstract The production of cement is growing every year due to its higher consumption in the construction industries. Several studies have been carried out that focus on the possibility of alternative cementing materials such as Industrial and agricultural wastes. Rice husk is one of such agricultural residues and cattle bone is animal waste that are available but didn’t get much attention as alternative cementing material. This study aimed to investigate the effect of partial replacement of cement by combining cattle bone ash and rice husk ash mix in cement mortar at 0%, 5% 10% 15% and 20% by volume of cement. The workability test, compressive strength, Ultrasonic Pulse Velocity, water absorption, and sulfate attack tests were conducted for different curing ages (3, 7, 28, 56, and 90 day). In addition, the morphology scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential thermal analysis (DTA), fourier transform infrared spectroscopy (FTIR) and Brunauer–Emmett–Teller (BET) surface area test, complete silicate analysis test was conducted. Compressive strength increases with an increment of from 0 to 10% replacement at 28 days of curing from 31.5 to 45.9 MPa and slightly decreased beyond 15–20% replacement with 39.9 MPa and 30.6 MPa. The result revealed that the mechanical performance of mortar indicated enhancement of calcium silicate hydrate gel, thus reduce the porosity of cement matric. Under scanning Electron Microscopy (SEM) image, mortar sample possessed a dense matrix with a widespread presence of calcium silicate hydrate (C–S–H) gels.
To produce calcium aluminate cement (CAC), bauxites are usually fused with lime/limestone at high temperature (1600 °C). At this temperature, the bauxite´s hydrates of alumina break down - dehydroxylation - and combine with calcium forming monocalcium aluminate (CA), the principal active phase in CAC.A previous study evidenced that the Saudi bauxite begins dehydroxylation at low temperature (300 °C). This paper investigates whether low temperature can produce a cement, to reduce the carbon footprint of cement production. Cements are sintered by fusing the bauxite with calcium sources (limestone and quicklime) at temperatures from 600 to 1200 °C.The results evidenced that limestone fusion is the most efficient method, as it renders hydraulic phases at 800 °C (C12A7) and 1000 °C (haüyne). The early release of Ca2+ from the limestone acts as a flux, lowering the breakdown point of the bauxite´s components. C12A7 (mayenite) which can speed up hydration and setting, appears widely in the limestone-bauxite cements, beginning at 800 °C and remaining stable up to 1200 °C.The bauxite´s gypsum released sulphur, affording the sintering of calcium-sulfoaluminate (haüyne) at 1000 °C. Therefore, the bauxite can produce sulfoaluminate cement, a green cement which can reduce carbon emissions and fight climate change.The bauxite´s high silica content and the breakdown of its kaolinite polymorph nacrite, facilitate the production of hydraulic calcium silicate clinkers (belite, andradite, gehlenite, wollastonite and prehnite) which afford strength on hydration.The fluxing action of iron, aluminium and sulphur, significant in the bauxite, lowered the clinkering temperature.
Daniel A. Geddes, Brant Walkley, Taku Matsuda
et al.
This paper describes the hydration products and microstructural formation processes that yield excellent mechanical properties in “zero-cement concretes” (ZCC) produced by chemical activation of a blend of silica fume, blast furnace slag, and fly ash, using a CaO-rich additive (commercially supplied as an expansive agent but taking a chemical activation role here), a high superplasticizer dose, and a very low water content. These concretes reach 70 MPa at 28 days and then continue to gain strength beyond 150 MPa after 5 years, either under sealed conditions or exposed on a rooftop in the climate of Tokyo, Japan. The reaction products of ZCC are dominated by C-A-S-H gel, accompanied by aluminate hydrates of different layered double hydroxide forms; this unconventional cementitious blend yields reaction products that are familiar from Portland cement and blended binder systems. The ferronickel slag used as fine aggregate in these mixes makes an important contribution to the balance of fresh-state and hardened-state properties by modifying hydration chemistry.
This paper presents a novel waste-heat-powered, wireless, and battery-less Industrial Internet of Things (IIoT) device designed for predictive maintenance in Industry 4.0 environments. With a focus on real-time quality data, this device addresses the limitations of current battery-operated IIoT devices, such as energy consumption, transmission range, data rate, and constant quality of service. It is specifically developed for heat-intensive industries (e.g., iron and steel, cement, petrochemical, etc.), where self-heating nodes, low-power processing platforms, and industrial sensors align with the stringent requirements of industrial monitoring. The presented IIoT device uses thermoelectric generators based on the Seebeck effect to harness waste heat from any hot surface, such as pipes or chimneys, ensuring continuous power without the need for batteries. The energy that is recovered can be used to power devices using mid-range wireless protocols like Bluetooth 5.0, minimizing the need for extensive in-house wireless infrastructure and incorporating light-edge computing. Consequently, up to 98% of cloud computation efforts and associated greenhouse gas emissions are reduced as data is processed within the IoT device. From the environmental perspective, the deployment of such self-powered IIoT devices contributes to reducing the carbon footprint in energy-demanding industries, aiding their digitalization transition towards the industry 5.0 paradigm. This paper presents the results of the most challenging energy harvesting technologies based on an all-silicon micro thermoelectric generator with planar architecture. The effectiveness and self-powering ability of the selected model, coupled with an ultra-low-power processing platform and Bluetooth 5 connectivity, are validated in an equivalent industrial environment to monitor vibrations in an electric machine. This approach aligns with the EU’s strategic objective of achieving net zero manufacturing capacity for renewable energy technologies, enhancing its position as a global leader in renewable energy technology (RET).
Ashtar S. AL-LUHYBI, Taghreed Khaleefa MOHAMMED ALI, Azad A. MOHAMMED
Geopolymer is known to have many structural and nonstructural benefits, but the attractive characteristic of this novel material is that it depends essentially on a byproduct from different industries, and the use of Portland cement is absent. This concrete is an environmentally friendly product and is essential as the sustainability issue is considered. Compared with the material properties, the behavior of reinforced concrete members made of geopolymer has gained less importance by past researchers. Therefore, this review paper aims to summarize the evidence of the structural behavior of geopolymer concrete beams to provide a better understanding of the characteristics of reinforced geopolymer beams. A total of sixteen published works on geopolymer beams reinforced with steel rebar have been reviewed, and it found that there are 83 beams tested in flexure and 29 beams tested to highlight the shear behavior. For comparison, some researchers have tested control beams made of Portland cement concrete (PCC). It is noted that geopolymer concrete (GPC) beams have a performance, in general, better than that of PCC beams in terms of strength and ductility. Design proposals for PCC beams could be safely used for GPC beams, and the software based on the finite element method accurately predicts the load-deflection response. However, further study is recommended to provide more detailed and cost-effective design methodologies for the potential use of GPC in large-scale field applications.
Heavy industries such as cement, iron and steel, oil refining, and petrochemicals are responsible for about 22% of global carbon dioxide (CO2) emissions. There exist several pathways for global CO2 mitigation. Capturing, storage, and utilization of CO2 (CCS and CCU) provide an operational solution for significant emission mitigation. High purity CO2 streams are the most interesting points for CCS and CCU. Pure CO2 streams are suitable for compression, transport, and storage. Capture technology categories are typically pre-combustion, oxy-fuel combustion, and post-combustion processes. Moreover, the main challenges of the robust industrial CCS/U development are the high costs of CO2 separation from flue gas or ambient air and the conversion of CO2 in various utilization pathways. This research study includes a summary of several CCS technologies and CCU pathways, their current status, cost, and industrial deployment.
Mitigation of greenhouse gas emissions is becoming a significant factor in all industries. Cement manufacturing is one of the industries responsible for greenhouse gas emissions, specifically carbon dioxide emissions. Pozzolanic materials have long been used as cement additives due to the pozzolanic reaction that occurs when hydrated and the formation a cementitious material similar to that of cement. In this study, shale, which is a common component found in wellbore drill cuttings, was used in various sizes and quantities to determine the effect it had on the mechanical properties of wellbore cement. The unconfined compressive strength of the cement containing shale was compared to the cement without shale to observe the effect that both the quantity and particle size had on this property. SEM–EDS microscopy was also performed to understand any notable variations in the cement microstructure or composition. The samples containing micron shale appeared to have the best results of all the samples containing shale, and some of the samples had a higher UCS than one or more of the base case samples. Utilization of cuttings as a cement additive is not just beneficial in that it minimizes the need for cuttings removal and recycling, but also in that it reduces the amount of greenhouse gas emissions associated with cement manufacturing.
The carbon footprint of cement industries has been a major environmental issue in recent decades. Carbon Capture and Storage (CCS), use of Supplementary Cementing Materials (SCMs) as partial replacement to cement, and use of nanotechnology are some approaches that are being tested and practiced for reducing the carbon dioxide (CO2) emissions from the cement industries. Each of these approaches, however, comes with their own limitations and the implementation in real industrial scenarios is yet a concern. This paper proposes an integrated approach where CO2 captured from cement plant will be utilized within the plant for producing nano calcium carbonate (CaCO3) for use in cement manufacturing process. This technology incorporates all the above three approaches and help cement industries produce sustainable, durable, and economical cement while reducing the CO2 emissions into the atmosphere: thus, leading towards green infrastructure and global environmental sustainability. Additionally, adoption of this technology ensures proper dispersion of nano materials thereby improving the performance of concrete. Further, this technology is economically attractive to cement industries as they will have a new product (nano CaCO3) with much higher cost than cement with potential of additional economic revenues.
Environmental sciences, Environmental effects of industries and plants
The application of waste materials in concrete is getting more popular in the concrete industries as it can reduce the associated costs and environmental impacts. The present study investigates the performances of concrete while incorporating polypropylene (PP) plastic, derived from waste plastic products, as a partial replacement of natural stone aggregate (SA) and burnt clay brick aggregate (BA). The main variables include the percentage of PP aggregate (PPA) (0%, 10 %, 20 %, and 30 %), water-cement ratio (0.45 and 0.55), and types of aggregate (SA and BA). Results are presented in terms of workability, hardened density, compressive, tensile strengths, modulus of rupture, modulus of elasticity (MoE), ultrasonic pulse velocity (UPV), and cost analysis. Furthermore, empirical equations are proposed for predicting different properties of concrete; especially, predicting compressive strengths from the UPV values. Results indicated that the slump value increased with increasing the percentage of PPA. Concrete with 10 % PPA exhibited higher compressive strength, modulus of rupture, and splitting tensile strengths, even, higher than that of the control stone aggregate concrete (SAC) and control brick aggregate concrete (BAC). The UPV values varied with aggregate types and PPA content. Both the compressive strength and the UPV values decreased with the increasing percentages of PPA from 10 to 30. Furthermore, SAC exhibited higher compressive strength and UPV values compared to BAC. A good correlation was found between the compressive strength and the UPV values for concrete with PPA. From the cost sensitivity analysis, it was observed that concrete containing 10 % PP content had the highest strength over cost ratio compared to the control and other PPA concrete. Therefore, it is recommended to use up to 10 % PPA either with stone aggregate or brick aggregate for structural concrete. Finally, this study will open new opportunities for producing green concrete by using non-biodegradable waste plastic materials.
Materials of engineering and construction. Mechanics of materials