scholarly journals Global CO<sub>2</sub> uptake of cement in 1930–2019

2020 ◽  
Author(s):  
Rui Guo ◽  
Jiaoyue Wang ◽  
Longfei Bing ◽  
Dan Tong ◽  
Philippe Ciais ◽  
...  
Keyword(s):  
Calcium Content ◽  
Cement Industry ◽  
Cement Kiln ◽  
Low Carbon ◽  
Uptake Capacity ◽  
Cement Production ◽  
Dominant Position ◽  
High Calcium ◽  
Estimation System ◽  
Kiln Dust

Abstract. Because of the alkaline nature and high calcium content of cements in general, they serve as a CO2 absorbing agent through carbonation processes, resembling silicate weathering in nature. This carbon uptake capacity of cements could abate some of the CO2 emitted during their production. Given the scale of cement production worldwide (4.10 Gt in 2019), a life-cycle assessment is necessary in determining the actual net carbon impacts of this industry. We adopted a comprehensive analytical model to estimate the amount of CO2 that had been absorbed from 1930 to 2019 in four types of cement materials including concrete, mortar, construction waste and cement kiln dust (CKD). Besides, the process CO2 emission during the same period based on the same datasets was also estimated. The results show that 21.12 Gt CO2 (18.12–24.54 Gt CO2, 95 % CI) had been absorbed in the cements produced from 1930 to 2019, with the 2019 annual figure mounting up to 0.90 Gt CO2 yr−1 (0.76–1.07 Gt CO2, 95 % CI). The cumulative uptake is equivalent to approx. 52 % of the process emission, based on our estimation. In particular, China's dominant position in cement production/consumption in recent decades also gives rise to its uptake being the greatest with a cumulative sink of 6.21 Gt CO2 (4.59–8.32 Gt CO2, 95 % CI) since 1930. Among the four types of cement materials, mortar is estimated to be the greatest contributor (approx. 58 %) to the total uptake. Potentially, our cement emission and uptake estimation system can be updated annually and modified when necessary for future low-carbon transitions in the cement industry. All the data described in this study, including the Monte Carlo uncertainty analysis results, are accessible at https://doi.org/10.5281/zenodo.4064803.

scholarly journals Global CO<sub>2</sub> uptake by cement from 1930 to 2019

2021 ◽  
Vol 13 (4) ◽  
pp. 1791-1805
Author(s):  
Rui Guo ◽  
Jiaoyue Wang ◽  
Longfei Bing ◽  
Dan Tong ◽  
Philippe Ciais ◽  
...  
Keyword(s):  
Calcium Content ◽  
Cement Industry ◽  
Cement Kiln ◽  
Low Carbon ◽  
Uptake Capacity ◽  
Cement Production ◽  
Dominant Position ◽  
High Calcium ◽  
Estimation System ◽  
Kiln Dust

Abstract. Because of the alkaline nature and high calcium content of cements in general, they serve as a CO2-absorbing agent through carbonation processes, resembling silicate weathering in nature. This carbon uptake capacity of cements could abate some of the CO2 emitted during their production. Given the scale of cement production worldwide (4.10 Gt in 2019), a life-cycle assessment is necessary to determine the actual net carbon impacts of this industry. We adopted a comprehensive analytical model to estimate the amount of CO2 that had been absorbed from 1930 to 2019 in four types of cement materials, including concrete, mortar, construction waste, and cement kiln dust (CKD). In addition, the process CO2 emission during the same period based on the same datasets was also estimated. The results show that 21.02 Gt CO2 (95 % confidence interval, CI: 18.01–24.41 Gt CO2) had been absorbed in the cements produced from 1930 to 2019, with the 2019 annual figure mounting up to 0.89 Gt CO2 yr−1 (95 % CI: 0.76–1.06 Gt CO2). The cumulative uptake is equivalent to approximately 55 % of the process emission based on our estimation. In particular, China's dominant position in cement production or consumption in recent decades also gives rise to its uptake being the greatest, with a cumulative sink of 6.21 Gt CO2 (95 % CI: 4.59–8.32 Gt CO2) since 1930. Among the four types of cement materials, mortar is estimated to be the greatest contributor (approximately 59 %) to the total uptake. Potentially, our cement emission and uptake estimation system can be updated annually and modified when necessary for future low-carbon transitions in the cement industry. All the data described in this study, including the Monte Carlo uncertainty analysis results, are accessible at https://doi.org/10.5281/zenodo.4459729 (Wang et al., 2021).

scholarly journals Thermoactivated Recycled Cement

2021 ◽  
Author(s):  
José Alexandre Bogas ◽  
Ana Carriço ◽  
Sofia Real
Keyword(s):  
Ordinary Portland Cement ◽  
Ghg Emissions ◽  
Resource Depletion ◽  
Cement Industry ◽  
Future Perspective ◽  
Low Carbon ◽  
Cement Production ◽  
Waste Concrete ◽  
Cement Based Materials ◽  
Main Production

The cement industry is currently faced by the great challenge of reducing its vast carbon footprint, due to being the second highest industrial greenhouse gases (GHG) emitter. This value is expected to further increase, since cement production is foreseen to rise by about 20% until 2050. Therefore, more eco-efficient alternatives to ordinary Portland cement have been developed towards a sustainable concrete industry. This chapter presents some of the latest advances in low-carbon thermoactivated recycled cements (RC) obtained from old waste concrete, leading to a significant reduction of the GHG emissions, while also encouraging the valorization reuse of waste materials and the reduction of natural resource depletion. The manufacture and general performance of RC, including the main production issues, rehydration behavior and phase and microstructure development, as well as its incorporation in cement-based materials are discussed. Some of the most recent research, main challenges and future perspective of RC are addressed.

scholarly journals FEASIBILITY ANALYSIS ON INDUSTRIAL SYMBIOSIS BETWEEN CEMENT INDUSTRY AND TEA INDUSTRY

2015 ◽  
Vol 4 (3) ◽  
pp. 20-34 ◽  
Author(s):  
Shailendra Kumar Yadav ◽  
R Kalaiyarasi
Keyword(s):  
Cement Industry ◽  
Effluent Treatment ◽  
Cement Kiln Dust ◽  
Cement Kiln ◽  
Industrial Symbiosis ◽  
Air Pollution Control ◽  
Optimum Dosage ◽  
Tea Industry ◽  
Removal Efficiencies ◽  
Kiln Dust

The project aims at analyzing the feasibility of utilizing cement kiln dust (CKD) in treating wastewater from tea industry with the concept of industrial symbiosis. CKD is the dust collected at the air pollution control device(s) associated with a kiln system from cement industry. A very less percent of CKD is recycled and the rest is land filled /stockpiled; disrupts groundwater through leaching of minerals. Cement Kiln Dust (CKD), rich in CaO, SiO2, behaves as a neutralizing as well as stabilizing agent for tea effluent treatment. The ability of CKD to reduce the BOD, COD, TSS, and phosphates in tea effluent was analyzed and the optimum dosage is determined. The effect of different dosages of Cement Kiln Dust ranging from (1-3) gm/l has been discussed on the bench scale tests. The results show that, for different CKD concentrations, high removal efficiencies of 94.4 and 99.0, 58.9 for BOD, TSS, phosphates and a lower efficiency for COD with 9.09 are achieved for 2.5gm/l. The persistent presence of color providing proteins theaflavins (TF) and the arubigins (TR) from the leftover tea leaves in the effluent imparts the low removal efficiencies of COD. However, the COD value is within the dischargeable limits (CPCB standards). Moreover, a considerable removal efficiency and high SVI of 0.181 makes CKD a feasible coagulant in treating tea effluent with optimum dosage of 2.5g/l. The objective of developing industrial symbiosis network was thus achieved using the CKD to treat wastewater from tea industries.   International Journal of EnvironmentVolume-4, Issue-3, June-August 2015Page: 20-34

Research Progress on Low-Carbon Technologies and Assessment Methods in Cement Industry

2021 ◽  
Vol 1035 ◽  
pp. 933-943
Author(s):  
Hai Tao Zhao ◽  
Yu Liu ◽  
Xiao Qing Li ◽  
Li Wei Hao
Keyword(s):  
Ghg Emissions ◽  
Assessment Methods ◽  
Cement Industry ◽  
Research Progress ◽  
Main Trend ◽  
Low Carbon ◽  
Cement Production ◽  
Technology And Assessment ◽  
Manufacturing Technologies ◽  
Low Carbon Technologies

As one of the pillar industries for social development and economic construction, cement manufacture is energy and carbon-intensive, whose greenhouse gas (GHG) emissions account for more than 6% of total global man-made GHG emission annually. With the growing attention on the problem of global warming, researching and promoting low-carbon manufacturing technologies to reduce GHG emissions have become the main trend in the development of cement industry under the new era. This article sorted out the low-carbon technologies for cement production reported in recent years, introduced the mainstream methods of GHG accounting and assessment such as life cycle assessment (LCA) and carbon footprint analysis (CFA), meanwhile reviewed the articles in the field of low-carbon technology and assessment methods in cement production, moreover, discussed the merits and demerits of various assessment methods and applicable fields, in order to provide suggestions and supports for low-carbon transformation of cement industry.

Characteristics of controlled low-strength materials incorporating cement kiln dust

2007 ◽  
Vol 34 (4) ◽  
pp. 485-495 ◽  
Author(s):  
M Lachemi ◽  
K M.A Hossain ◽  
M Shehata ◽  
W Thaha
Keyword(s):  
Strength Properties ◽  
Cement Industry ◽  
Cement Kiln Dust ◽  
Cement Kiln ◽  
Study Phase ◽  
Strength Material ◽  
Preliminary Study ◽  
Low Strength ◽  
Cement Manufacturing ◽  
Kiln Dust

This paper presents a study that focuses on evaluating the feasibility of incorporating cement kiln dust (CKD) in the development of controlled low-strength materials (CLSM). A preliminary study (phase I) was conducted (based on fresh and strength properties) to understand the behaviour of 12 selected CLSM mixtures where CKD and cement content varied from 4% to 45% and from 2% to 4% of total mass, respectively. Subsequently, four best CLSM mixes were selected for a detailed study (phase II), which investigated fresh and hardened properties, addressed durability issues, and made recommendations for suitable mix designs for field applications. The research suggests that CLSM with acceptable properties can be developed using moderate volumes of CKD (up to 15% by mass). A combination of 2% cement and 10% CKD or 15% CKD and no cement can provide a mix that satisfies the requirements of a CLSM. Sustainable development in the cement industry can be partly achieved by producing CKD-based CLSM, as it consumes cogenerated products from the cement manufacturing process.Key words: cement kiln dust, controlled low-strength material, mix design, fresh–mechanical properties, durability.

scholarly journals Physico-Mechanical Properties of Bricks Manufactured using Cement Kiln Dust

2020 ◽  
Vol 9 (3) ◽  
pp. 1804-1808
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Waste Management ◽  
Industrial Waste ◽  
Cement Content ◽  
Cement Industry ◽  
Cement Clinker ◽  
Cement Kiln Dust ◽  
Cement Kiln ◽  
Kiln Dust

the actual increase in global industrial production and manufacturing, produces a continuous increase in amount of industrial waste and continues to emit an all-time high amount of air pollutants and greenhouse gas emissions. To fight and mitigate these phenomena, proper Waste Management became the pillar of most environmental strategies worldwide. By reduction of consumption, re-use of goods and recycling of products, waste management aims to preserve the resources and to protect the environment. The Cement industry is one of the most important industrial sectors for society development; however it also has significant negative environmental impacts due to its emissions and production of waste. Cement kiln dust (CKD) is an industrial waste or by product which results from cement manufacturing. CKD is fine grained, solid, highly alkaline particulate material chiefly composed of oxidized, anhydrous, micron-sized particles collected from electrostatic precipitators during the production of cement clinker. This research examines the effects of using large amounts of CKD to replace the cement content in the fabrication of solid cement bricks. It is triggered by the quadruple objectives of reducing the amount of cement consumption, disposing efficiently of its industrial waste and producing economic bricks with safe strength. The purpose of this paper is to assess the properties of solid cement bricks containing different amounts of CKD. Cement bricks produced using different amounts of CKD were tested to find their properties and final comparison has been made to identify the effect of using different CKD/Cement ratio on the performance of bricks compared to the reference specimen produced using cement only with no CKD. For the brick mixes, Ordinary Portland cement (OPC), with two cement content of 200kg/m3 and 250kg/m3 were used throughout this investigation. The physical properties; unit weight, water absorption and mechanical properties; compressive strength, flexural strength, of the produced bricks were determined. Results showed that partial replacement of OPC with CKD reduces the brick compressive strength by 18% to 23% for CKD/OPC ratio of 30% and by 36% for CKD/OPC ratio of 50% and in all cases the strength remains largely higher than the standard limit for load bearing bricks.

Fresh and hardened properties of self-compacting concrete containing of cement kiln dust

2019 ◽  
Vol 10 (1) ◽  
pp. 13 ◽  
Author(s):  
Ibrahim Saad Agwa ◽  
Omar Mohamed Omar Ibrahim
Keyword(s):  
Rotary Kiln ◽  
Raw Materials ◽  
Economic Problem ◽  
Cement Industry ◽  
Experimental Program ◽  
Cement Kiln Dust ◽  
Cement Kiln ◽  
Self Compacting Concrete ◽  
Cement Replacement ◽  
Kiln Dust

There are many wastes form the cement industry among them cement kiln dust (CKD). This residue is obtained after the process of burning the raw materials of cement in the rotary kiln where it is suctioned by fans during the clinker exit of the rotary kiln. Cement dust is a major environmental and economic problem in terms of high quality air pollution ranging from (20-100) microns and the proportions of chlorides, sulphates, alkali and lime living in a way that threatens the general health of human, as well as water pollution if the waste is discharged by rivers and waterways. This investigation’s main objective is to present the potential of using CKD as a cement replacement in self-compacting concrete (SCC). Eight mixes incorporating CKD with partial cement replacement of 0%, 5%, 10%, 20%, 30%, 40%, 50% and 75% in addition to control mix were investigated. The properties of all mixture were determined. Based on the experimental program results, it was found that SCC mixture incorporating 5% to 10% of CKD was almost similar to that of control mixture. The workability of SCC concrete decreased as CKD replacement increased. This established benefits of substituting cement by CKD to make SCC.

scholarly journals Recent Progress in Green Cement Technology Utilizing Low-Carbon Emission Fuels and Raw Materials: A Review

2019 ◽  
Vol 11 (2) ◽  
pp. 537 ◽  
Author(s):  
Ali Naqi ◽  
Jeong Jang
Keyword(s):  
Carbon Dioxide ◽  
Carbon Dioxide Emissions ◽  
Alternative Fuels ◽  
Raw Materials ◽  
Low Cost ◽  
Cement Industry ◽  
Industrial Wastes ◽  
Low Carbon ◽  
Cement Production ◽  
Cement Manufacturing

The cement industry is facing numerous challenges in the 21st century due to depleting natural fuel resources, shortage of raw materials, exponentially increasing cement demand and climate linked environmental concerns. Every tonne of ordinary Portland cement (OPC) produced releases an equivalent amount of carbon dioxide to the atmosphere. In this regard, cement manufactured from locally available minerals and industrial wastes that can be blended with OPC as substitute, or full replacement with novel clinkers to reduce the energy requirements is strongly desirable. Reduction in energy consumption and carbon emissions during cement manufacturing can be achieved by introducing alternative cements. The potential of alternative cements as a replacement of conventional OPC can only be fully realized through detailed investigation of binder properties with modern technologies. Seven prominent alternative cement types are considered in this study and their current position compared to OPC has been discussed. The study provides a comprehensive analysis of options for future cements, and an up-to-date summary of the different alternative fuels and binders that can be used in cement production to mitigate carbon dioxide emissions. In addition, the practicalities and benefits of producing the low-cost materials to meet the increasing cement demand are discussed.

Life Cycle Assessment of Comprehensive Utilization of Calcium Carbide Slag in Cement Kiln

2020 ◽  
Vol 993 ◽  
pp. 1487-1495
Author(s):  
Xin Ping Lin ◽  
Ai Wei Liu ◽  
Yun Fa Feng ◽  
Qi Ling Chen ◽  
Tao Chen ◽  
...  
Keyword(s):  
Life Cycle Assessment ◽  
Emission Reduction ◽  
Calcium Carbide ◽  
Cement Industry ◽  
Cement Clinker ◽  
Cement Kiln ◽  
Cement Production ◽  
Comprehensive Utilization ◽  
Carbide Slag ◽  
Portland Cement Clinker

The recycling utilization of solid waste is an important technical means for the sustainable development of the cement industry in China. Calcium carbide slag is a special solid waste in China, which can be used for cement production with a great advantage on CO2 emission reduction. With an view to providing methodological and data support for the development of policies in the cement industry, this paper quantitatively analyzes the environmental effects/environmental benefits of the comprehensive utilization of calcium carbide slag in cement kiln by comparing the traditional system of Portland cement clinker completely produced by natural resources with the system of cement clinker produced by calcium carbide slag based on the life cycle assessment (LCA) method given in standards and specifications of ISO 14040 series. The results show that the latter system has a better effect in material saving and carbon emission reduction, will increase the energy consumption in cement production process, and also slightly increase other pollutants (e.g. SOx, NOx, etc.) emission. The GWP, AP and EP indicators of the calcium carbide slag cement clinker system decrease compared with those of the Portland cement clinker system, while other indicators do not differ much or even slightly increase.

scholarly journals CO2 reduction options in cement industry: The Novi Popovac case

2010 ◽  
Vol 14 (3) ◽  
pp. 671-679 ◽  
Author(s):  
Gordana Stefanovic ◽  
Goran Vuckovic ◽  
Mirko Stojiljkovic ◽  
Milan Trifunovic
Keyword(s):  
Fly Ash ◽  
Co2 Emissions ◽  
Cement Industry ◽  
Mitigation Strategies ◽  
Partial Substitution ◽  
Co2 Removal ◽  
Low Carbon ◽  
Emission Mitigation ◽  
Cement Production ◽  
Ash Disposal

The cement industry contributes about 5% to global anthropogenic CO2 emissions, and is thus an important sector in CO2-emission mitigation strategies. Carbon dioxide is emitted from the calcination process of limestone, from combustion of fuels in the kiln, and from the coal combustion during power generation. Strategies to reduce these CO2 emissions include energy efficiency improvement, new processes, shift to low carbon fuels or waste fuels in cement production, increased use of additives in cement production, alternative cements, and CO2 removal from flue gases in clinker kilns. Increased use of fly ash as an additive to cement and concrete has a number of advantages, the primary being reduction of costs of fly ash disposal, resource conservation, and cost reduction of the product. Since the production of cement requires a large amount of energy (about 2.9-3.2 GJt-1), the substitution of cement by fly ash saves not only energy but also reduces the associated greenhouse gas emissions. The paper evaluates the reduction of CO2 emissions that can be achieved by these mitigation strategies, as well as by partial substitution of cement by fly ash. The latter is important because the quality of the produced concrete depends on the physical-chemical properties of the fly ash and thus partial substitution as well as the type of fly ash (e.g., the content of CaO) has an effect not only on energy consumption and emissions, but also on the produced concrete quality.

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