Cement Production Process Research Articles

Evaluating the Carbon Footprint of Cement Plants Integrated With the Calcium Looping CO2 Capture Process

Cement industry is estimated to account for ~6–7% of anthropogenic CO2 emissions globally. Therefore, the identification of innovative solutions for their mitigation is both a priority and a challenge. The integration of carbon capture and storage technologies into the industrial production process is considered among the most viable solutions for this purpose, and calcium looping (CaL) represents one of the most promising. A key research challenge points to maximize process efficiencies and minimize production cost to decouple cement production from carbon emissions. The carbon capture process proposed in this work is a looping system where CO2 is absorbed by calcium oxide (CaO) in the first reactor (carbonator) and the calcium carbonate (CaCO3) produced is regenerated in an oxy-fired calciner. During calcination, CO2 is released from the sorbents, purified, compressed, and then made available for geological storage. In this study, greenhouse gas (GHG) emissions related to two cement production systems with CaL carbon capture are evaluated: the tail-end CaL carbon capture and the integrated CaL carbon capture. The carbon footprint is complemented with the assessment of the resources depletion mineral and elements and the demand of primary energy. An eco-design approach was pursued by carrying out a life cycle assessment to identify the environmental hotspots and which CaL integration approach presents a higher potential for cement industry decarbonization. The results of the analysis were compared with a conventional cement production process. The results show that the GHG emissions may be reduced by 74% with a tail-end approach and 71% when the CaL is fully integrated into the cement production process. When a future perspective, with higher penetration of renewable energy resources into the electricity sector, was modeled, the results showed that CaL integrated into the clinker production process is more promising in terms of reduction of the carbon footprint, rather than the tail-end solutions. Primary energy consumption from non-renewables is substantially impacted by CaL, with the integrated CaL configuration showing to be a more efficient solution because of less primary energy consumption (coal).

Decarbonization options for cement production process: A techno-economic and environmental evaluation

The long-term environmental targets require significant cuts of CO2 emissions in fossil fuel-intensive industrial processes. Currently, the cement production sector is responsible for approximate 8% of world anthropogenic CO2 emissions. The present paper assesses from the technical, environmental and economic point of view different decarbonization systems integrated into cement production plants. As CO2 capture technologies, the tail-end post-combustion capture using amine-based chemical scrubbing, membrane and calcium looping were assessed as well as the partial and total oxy-combustion options. The size of decarbonized cement concept has a capacity of 1 Mt/y with 90% CO2 capture rate. The overall techno-economic assessment was based on modelling and simulation to assess the key performance indexes. A non-decarbonized cement plant was also assessed for comparison to calculate the energy and economic penalties for decarbonization. The membrane and oxy-combustion concepts have the lowest cement production cost in comparison to the reactive absorption and adsorption concepts (112–119 vs. 125–145 €/t). The full oxy-combustion plant followed by the membrane concept exhibit the lowest CO2 avoided costs comparable with the current emission tax (60–70 vs. 60–80 €/t). The reactive gas–solid system (calcium looping) exhibits superior indicators than the chemical scrubbing system due to high temperature heat recovery.

Analisis Kegagalan Permukaan Kontak Rail dan Wheel pada Overhead Travelling Crane

For the sake of the smooth process of cement production, it is necessary to maintain each component of the production. One of the tools that play an important role in the maintenance and production of cement is the Overhead Traveling Crane, which is a combination of a separate lifting mechanism with a frame to lift and move loads that can be hung freely or attached to the crane itself. The problems that arise in the Overhead Traveling Crane include the reverse direction of the motor rotation due to an error in the motor connection, the motor cannot start due to a disconnected power supply, the occurrence of bending (curving) on ​​the girder due to lifting operations that exceed the maximum capacity which can also accelerate service life. of the girder, wear on the wheel due to high workload during operation. Due to the need for very long use, periodic maintenance is needed so that it can be in normal condition for a long time. The main parts that support the overall weight of the crane are rails and wheels. This journal discusses the analysis of failures that occur due to contact between rails and wheels that occur in a cement factory. Failure analysis is done by testing the hardness of both the wheel and the rely which is considered to have failed or is no longer suitable for use. Then review the results of direct field observations with data from hardness tests and literature studies related to wheels and rails. after that it was concluded that the company considered for the procurement of rails and wheels. The conclusion obtained is that the hardness value on the rail is lower than on the wheel. Resulting in failure of the rail so that the rail must be replaced.

A Contribution towards a More Sustainable Cement: Synergy of Mill Scales, Greek Wet Fly Ash, Conventional Raw Materials and Clinkering Temperature

Portland cement is the most common type of cement and one of the most important ingredients in concrete. Concrete, on the other hand, is the most used building material worldwide just behind the water with an increasing usage trend in infrastructure for the upcoming years. During the production process of cement, massive CO2 emissions are released into the environment, while large amounts of raw materials and energy are consumed. In the present study, Portland type cement was prepared in laboratory-scale by Greek Wet Fly Ash and Mill Scales, as well as conventional raw materials such as limestone, shale and lava. The experiments were conducted at 1450 °C and 1340 °C. The fired compositions were characterized by XRD, Q–XRD, optical microscopy, SEM/EDS and the concrete specimens were tested for their compressive strength. The results indicated that formation of cement clinker at lower temperatures (1340 °C) is feasible with the combined use of natural raw materials and industrial byproducts following the standard production route of cement industries. Finally, the so-obtained cement presented compressive strength values comparable to the conventional ones fired at 1450 °C.

Cement industry – Associated emissions, environmental issues and measures for the control of the emissions

The cement industry though the backbone of modern construction and civilization is associated with the emission of diverse atmospheric pollutants with numerous attendant effects on the balance of ecosystem, human and environmental health and the global climate in general. Despite the huge advantages derivable from the industry, exploitation and processing of cement must be done in a sustainable manner to prevent irreversible damage to human, animal and vegetation health as well as the environment. Research papers were reviewed from different databases like ScienceDirect, ResearchGate, Google scholar, and Scopus the chief air pollutants are the inorganic gaseous emissions (carbon dioxide (CO2), carbon monoxide (CO), oxides of nitrogen (NOx), oxides of sulphur SO2), particulates of various size ranges and elemental emissions. The present study carries out holistic review of the cement production process with a view to identifying the principal air pollutants, sources and associated environmental issues. The study also reviews the pollution control measures currently in use and calls for a concerted effort from researchers, industry operators and regulators at working to reduce emissions with a view to upholding environmental sustainability.

ECO FRIENDLY HIGH EARLY STRENGTH SELF COMPACTING CONCRETE USING KAOLIN AND WASTE MARBLE DUST

The growth and development of infrastructure in Indonesia is currently growing very rapidly, and the cement production process produces the second largest amount of carbon dioxide after waste, which plays an important role in the current global warming. Self compacting concrete is one of the biggest innovations in the field of construction, Self compacting concrete is one of the biggest innovations in the construction field, where this concrete has high workability but does not ignore compressive strength. Therefore, new, sustainable materials are needed to replace cement production, but they are also required for the workability required to make self-compacting concrete. Green concrete concept, the use of kaolin, and marble dust waste, can be a solution to replace some cement. This innovation research uses XRF or X-ray fluorescence methods to identify and analyze the constituent elements of self-compacting concrete innovations. In this study, self-compacting concrete was obtained using (marble dust waste) which replaced 15% cement, and kaolin which replaced 10% concrete waste. with the main element calcium oxide (CaO) and containing (SiO) can be used as an additive or partial replacement of cement in the manufacture of concrete and kaolin can be obtained from kaolin mines spread across Indonesia, and waste marble dust can be obtained from marble processing, for information 25% of the mass of marble will be lost in the cutting process obtained from marble companies in Solo Raya, the slump flow test measurement is carried out with reference to according to the rules of SNI 1972-2008 and the workability of self-compacting concrete also meets the required requirements. So it can be concluded that it can be a reference source by utilizing waste in Indonesia, easy to obtain, and effective.
 
 Keywords: Self-compacting concrete, waste marble dust, kaolin

Eco-friendly fibre reinforced geopolymer concrete: A critical review on the microstructure and long-term durability properties

The environmental impact caused by the production process of ordinary Portland cement (OPC) concrete is a major challenge that requires demanding solutions in the construction sector. In the process of substituting OPC concrete production, the development of geopolymer concrete (GPC) is considered as the major breakthrough. However, research works related to durability of fibre reinforced geopolymer in several corrosive environments, i.e., sewage conveyer concrete pipeline, wastewater treatment, and offshore structures is limited compared to other types of concrete structures, and which is essential to estimate the long-term performance of concrete structure in extensive engineering applications. This review paper analyzes and discusses the mechanical and durability related properties of GPC containing various supplementary binding materials together with organic or synthetic fibres exposed to chloride salt, acid, and sulfate solution. Significant findings have concluded that the better long-term performance of geopolymer concrete is explained than OPC concrete, the durability mechanism is greatly affected by the calcium content. The fly ash/slag based geopolymer concrete geopolymer concrete specimens immersed in MgSO4 didn’t indicate a certain dimensional change in the first 120 d exposure, except that of salt deposition. Whereas, the conventional ordinary Portland cement, showed a 0.0184% expansion. Further, alkali activated slag mortar shows an approximate of 12 mm chloride penetration compared to the 10 mm depth of concrete specimens with a 25 w.t % fly ash replacement. Increasing the cement content from 10% to 20% had no significant effect on the properties of fly-ash based geopolymer concrete with crumb rubber and steel fibre subjected to normal and acid environmental exposure, considering the chemical reaction of sulfuric acid and calcium, and this chemical reaction led to the destruction of C-S-H bonds and production of different gypsums. The impact of fiber on the long-term behavior of geopolymer concrete have been highlighted. At last, potential recommendations and notable challenges have been forwarded for further studies on the durability of GPC.

Bowtie Method: Study of Occupational Health and Safety Risks in Cement Production Process

The kiln area is an area that has a very complex hazard potential in the cement production process. This study aimed to assess the risks of occupational safety and health during the production process in the kiln area of ​​PT. X uses the bowtie method. This study used a qualitative descriptive design. The informants used were three managers of the clinker production department, one safety manager, and one field operator. Research data were collected through interviews and observations. The data were analyzed qualitatively using the bowtie method. The study results stated that hot dust could be dangerous if it comes out of the system caused by positive pressure, such as the Induced Draft Fan (IDF) turning off, causing losses such as burns to workers. Heat can be dangerous if it experiences a significant increase due to excess fuel, causing losses, such as health-related illnesses. Preventive controls were carried out such as routine inspections. Mitigation controls were carried out such as light signals. Escalation factors can thwart hot dust and heat control, such as the deformation of raw meals. Escalation factor control, such as the implementation of work instructions. PT. X has carried out control in the kiln area, but additional controls are needed.

Effect of Curing Temperature on the Mechanical Strength of Alkali Activated Laterite Geopolymeric Samples

A huge amount of carbon dioxide is released in the Portland cement production process. A large quantity of greenhouse gases is produced because of the significant amount of energy consumption via making bricks through firing. Using the pozzolanic sources containing the aluminosilicate and alkaline reagents, a new type of green materials called geopolymeric materials are produced with quite lower environmental hazards. The use of laterite as an iron-rich aluminosilicate material has a high potential for building materials. In this study, the effect of the curing temperature and characteristics of the alkaline reagent including the concentration of sodium hydroxide solution and the water-glass to sodium hydroxide mass mixing ratio on the mechanical strength of the laterite-based, oven-cured geopolymer samples was investigated. The results showed that the curing temperature had a significant effect on the compressive strength of the laterite-based geopolymer samples so that with a 15°C change at the curing temperature, the compressive strength of the samples could be multiplied and a sharp increase in the mechanical strength could occur. Also, according to the results of this study, the 6 M sodium hydroxide is recommended for the construction of the laterite-based geopolymer materials with low cost and relatively high strength, and for the construction of higher-strength building materials, the 14 M sodium hydroxide is recommended.

Mechanical Properties Prediction of Normal and High Strength Geopolymer Concrete

The production process of cement is the main binder material in concrete usually accompanied by carbon dioxide emission. Therefore, geopolymer concrete (GPC) an alternative binder material was developed as a replacement for cement. In order to make this promising material more common in constructions and applicable for different design purposes further investigations for GPC mechanical properties were needed. This work aims to predicate the splitting tensile strength, modulus of elasticity and flexural strength for normal and high strength GPC by deriving new equations covering a wide range of compressive strength based on data available from previous work. Equations behavior along the changes in compressive strength from normal to high is adopted in comparisons as illustrated. The results show that the proposed equations, as compared with other equations established by previous works, provide a steady behavior for the various values of compressive strength especially for high strength. The coefficient of variation (COV) used as additional comparison criteria, and shows that the proposed equations provide better estimation of GPC mechanical properties.

Energetic assessment of a precalcining rotary kiln in a cement plant using process simulator and neural networks

Cement production has been increasing rapidly leading to energy consumption, with serious cost implications and environmental challenges. Energy efficiency is a key component required to maintain the cement company’s environmental strategy. In this study, Aspen Plus process model and neural networks are used to assess the energetic efficiency of a precalcining rotary kiln in a cement production process. Aspen Plus process simulator estimated energy efficiency at 61.30 % using the first law of thermodynamic. Further, for the ANN model, kiln feed, kiln gas, calciner gas, clinker cooling air, and primary air were the operation parameters inputs. ANN model is validated and demonstrated it is capable of predicting cement rotary kiln energy efficiency accurately with a correlation coefficient (R2) of 0.991. In conclusion, the Bootstrap aggregated neural network (BANN) was used to search the optimal operational parameters in achieving the lowest mean square error (MSE) of the energy efficiency. The MSE for training, testing, and validation data sets were 3.64 × 10-5, 3.70 × 10-5, and 5.00 × 10-5 for in the estimation of rotary kiln system energy efficiency. To achieve this optimal condition of 61.5 % energy efficiency, the optimal parameters as determined by ANN (BANN) were kiln feed of 205050 kg/hr, kiln fuel gas of 2821 kg/hr, calciner fuel gas of 5648 kg/hr, clinker cooling air of 247463 kg/hr and primary air of 7309 kg/hr. Consequently, it is recommended that ANN should be combined with Bootstrap aggregated neural network (BANN) for effective prediction and monitoring of energy efficiency for precalcining rotary kiln system.

A Calculation Approach of Embodied Energy, Carbon Emission and Eco-Costs on Waste Recycled Composite Materials

ABSTRACT The issue of waste recycling has recently become a major topic of research, particularly regarding building material technology. From the subject, numerous studies discussed recycling waste into building components, for instance, wall panels, mixed concrete material, concrete bricks, etc. Nevertheless, it brought another environmental issue due to the use of cement as the major ingredient. The cement production process is releasing carbon emissions that have a negative impact on the environment. The recycled materials that used as concrete components also, from its basic form, have a negative impact on the environment. Disposable diapers and plastic PET are non-degradable materials that are hard to demolish. The paradox has created pros and cons, especially in environmental impact-based research. This study gives calculation approach in determining the environmental impact using manual database. It employs several environmental impact indicators such as embodied energy (EE), carbon emissions (CE) that come out during the manufacturing process of the composite material product, and the environmental costs called eco-cost (EC) as the key indicators. Three types of waste concrete materials were analyzed, such as disposable diapers concrete, PET concrete, and shredded wood concrete. The result showed in term of EE, the material manufacturing is very important to decrease the EE. The material selection that has lower EE is important to reduce EE in the building. Additionally, the result showed the beneficial environmental impact in terms of CE and EC, the waste materials could reduce the impact due to recycling credit that applies to the process.

Development of high-ferrite cement: Toward green cement production

The reduction of energy consumption and CO2 emissions is essential for the development of cement industry. To this end, this work designed and prepared a green cementitious material to reduce the clinkering temperature and CO2 emissions by increasing the amount of ferrite as an intermediate mineral in the cement production process. The properties of the intermediate minerals, namely tricalcium aluminate (C3A) and tetracalcium ferroaluminate (C4AF), in terms of liquid viscosity at high temperatures and the synergistic interactions between the mineral phases formed at different calcination temperatures during the hydration process were systematically studied. The results indicate that, by adjusting the composition, microstructure, and liquid viscosity of the intermediate minerals and the clinkering regime, a high-ferrite cement (HFC) with high activity can be prepared at a calcination temperature of 1375 °C, which is about 50–100 °C lower than that of ordinary Portland cement. Consequently, the HFC obtained at a temperature of 1375 °C exhibits an excellent compressive strength of 72.7 MPa at a curing period of 28 days. Furthermore, according to the environmental evaluation performed, the prepared HFC can effectively reduce the energy consumption by 17.0%–20.3% and CO2 emissions by 15.0%–18.6% compared to ordinary Portland cement, indicating that high-ferrite cement can have promising applications in the protection of the environment and green construction industry.

Gaseous air pollutants dispersion emitted from point and line sources by coupling WRF-AERMOD models (Case study: Lowshan, Guilan Province, Iran)

The cement factories in urban areas can affect the air quality of cities due to the variety of pollutants emitted from cement production processes. In the present study, the impacts of the Khazar cement factory and two transportation axes between Guilan and Qazvin provinces were investigated on the air quality of Lowshan in Guilan Province, Iran in 2019. Due to the lack of suitable meteorological data for dispersion modeling, the WRF model was used to predict the meteorological parameters. The pollutants dispersion modeling was conducted by AERMOD software and the accuracy of results was confirmed by field measurements of NO2 obtained by passive samplers. The CO and NO2 dispersion modeling results showed that the air quality of Lowshan is in an acceptable situation compared to the ambient air quality standards. So that, the maximum one-hour concentration of NO2 in most residential areas was lower than the ambient standard, and only in small parts of the areas close to line sources, the concentration value was close to the standard limits. The maximum value of annually-averaged concentration of NO2 and the maximum one-hour concentration of CO were 17 ppb and 2.5 ppm, respectively, which are much lower than the clean air standards. Further investigation showed that in the cold weather seasons, due to the less vertical displacement of air and the decrease in the boundary layer height, the concentration of pollutants in the urban environment is higher than that in the warm weather seasons. Considering the night and day time wind roses showed that despite the existence of valley-mountain structure in the city, the air quality of the city is not affected by the mountain and valley breezes and also night and day wind roses do not follow the trend of these breezes.

Fate of Lead and Cadmium in Precalciner Cement Plants and Their Atmospheric Releases.

Disclosing the fate of lead (Pb) and cadmium (Cd) during the cement production process is the key to control their atmospheric emissions, which have not attracted much attention yet. In this study, three precalciner cement plants (CPs) using different raw materials in Guizhou Province in Southwest China were investigated. It showed that the concentrations of Pb and Cd in different raw materials and the associated total metal input of these materials were different among CPs; the behavior of Pb and Cd were almost the same during the clinker production process that there has been no accumulation of these two elements inside the system, and nearly all input of Pb and Cd were discharged by the clinker. Although the temperature of clinkerization was pretty high of 1450 °C, the atmospheric emission ratio of both metals was negligible (<0.006% for Pb and <0.002% for Cd of the total output, respectively); the main reason might be that the two elements were incorporated into the minerals of clinker, either as silicate or sulfate. The long-term environmental impacts of some high Pb-and Cd-laden clinkers and cement need to be monitored and evaluated.

Strategic Evaluation Plan and Improvement of Cement Plants (Iraqi Kurdistan Region - as a Case Study)

The cement plants in the Kurdistan Regional Government of Iraq (KRG) have made a considerable contribution to the economy of the region and almost dominated the cement market in the entire region and middle and south of Iraq. The cement plants as a part of KRG’s industrial sector needs to consider strategic planning, through this research the condition and quality of the cement plants in KRG have been evaluated, using Strengths, Weaknesses, Opportunities, and Threats analysis (SWOT Analysis) technique as a strategic planning tool to demonstrate weakness points and strong points in the cement production process and to review opportunities to turn weaknesses into strengths while identifying the challenges facing this process and suggesting strategies to develop the cement plants. The main aim of the current study is to strategically evaluate, plan, and improve cement plants in KRG through the application (SWOT Analysis Technique). To achieve the study objectives, the methodology consists of a literature survey and field survey; including Interviews, field visits, data collection, presentation, analysis, and discussion of the results. In this study the reality of cement production in Iraq and Kurdistan region of Iraq has been demonstrated, the research sample was Gasin Cement Company (GCC) located in Sulaimaniya Governorate, SWOT analysis has been conducted to study the reality in the plant, some strong points, weakness points, opportunities, and threats have been founded. As a strong point; the quality of cement in GCC is high then as a weakness point Absence supervision on contractor’s work, after that as an opportunity Iraqi government has prevented the import of cement since 2016, finally as a threat the fluctuation of oil price does have dangerous effects on the cement market.

Optimizing the Preventive Maintenance Scheduling Based on Dynamic Deterministic Demand in The Cement Manufacturing

Preventive maintenance is a planned and scheduled maintenance method that is carried out before a machine failure occurs. The maintenance schedule can be determined based on experience, historical data, or recommendations. Selecting the maintenance schedule greatly affects the production system. The Clin machine in cement manufacturing has an important role in the cement production process. During treatment, the client machine cannot produce clinker, so it is necessary to plan a production system to meet the demand. This paper aims to design an optimization model for determining the preventive maintenance schedule for cement manufacturing by considering the production process and inventory control. Mathematical models with binary options are used to model that system. The model supports showing the optimal preventive maintenance schedule for the ciln machines with a binary decision each period. This mathematical model describes the interaction of production planning, inventory control, and scheduling of total maintenance on a kiln machine. The goal of this system is to determine the optimal preventive maintenance schedule with minimum costs. In addition, the system's output is the optimal production and inventory decision rule for each period. Based on the analysis and simulation of the model with the deterministic and dynamic demand, the optimal preventive maintenance schedule is in the 9th and 21st periods. The kiln machines are maintained every July with minimal costs. The model scenario shows the interaction of the variables and the sensitivity of the production capacity and demand to the decision rule of the variable.

Multi-objective optimization design of cement grate cooler control system based on improved long short-term memory network

For the cement production process, the optimization method of the grate cooler is important in reducing energy consumption and ensuring product quality. As a complicated and slow control process, there are several control objectives of the grate cooler, which are determined by design parameters. To compute the time delay of the design parameters automatically, we propose an improved long short-term memory with adaptive computation time (ACT-LSTM) model for objective prediction. An improved multi-objective optimization algorithm named bounded stable non-dominated sorting genetic algorithm II (BS-NSGA-II) is proposed to solve the optimal solutions. With the proposed methods, the average electricity consumption is reduced by 13.2%, the secondary air temperature is increased, the clinker outlet temperature is stabilized in a reasonable range, and the design parameters change smoothly. The experiment results have indicated that the proposed method is effective in the optimization of objectives and the stability operation of the equipment.

Тенденции развития цементной индустрии в Узбекистане

The article provides an overview and analysis of the cement industry in Uzbekistan. The authors analyzed the volume of construction work, the volume of production and sales of cement products on the exchange, as well as the target parameters of the production of cement products in 2019–2025. Particular attention is paid to the technological process of cement production, in particular dry and wet methods. The advantages and disadvantages of each production technology are presented in detail. The authors reviewed the existing and projected cement manufacturing enterprises in Uzbekistan.

Implementation of Lean Manufacturing in a Cement Industry

The lean manufacturing concept is a systematic minimization of waste and non-value activities in production processes introduced by the Toyota production system. In this research, lean manufacturing is implemented in a cement production line. Value Stream Mapping (VSM) is applied to give a clear picture of the value chain in cement production processes and to highlight the non-value-added in the shop floor. To begin, the existing VSM is constructed based on the information and data gathered during visiting and observing the manufacturing process in the firm. As a result, the excess inventory between workstations was identified as a major waste generation, hence, the proposed VSM conducts further improvement and makes action plans to alleviate the unwanted activities. Then, the takt time to ensure smooth material flow and to avoid any occurring delay or bottleneck in the production line was figured out. The supermarket pull-based production control is suggested to be adopted in the future map. Two pull production strategies are selected in this case. The first is applying the Kanban system to control the level of inventory between workstations. The other is the CONWIP approach to control the amount of work in process to the entire production line. The outcome of the proposed models indicates a decrease of the none-value time from 23 days in the current state to about 4 and 2 days in Kanban and CONWIP systems respectively, so the CONWIP was suggested as most efficient. Some suggestions for further research are also mentioned.