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Sustainable Development
Published in Kyoung Hee Kim, Microalgae Building Enclosures, 2022
Growing construction activities to accommodate urbanization along with affluent lifestyles have turned the building sector into a major contributor to environmental impact and non-renewable resource use. The global construction market is expected to grow by 85%, reaching $15.5 trillion worldwide by 2030, and three countries lead the way– China, United States, and India – accounting for 57% of all global growth.25 Accordingly, building materials production, especially steel manufacturing and cement production, will continue to grow. Steel production is the highest industrial energy consumer due to the use of blast furnaces typically powered by coal power plants. The cement industry is the second largest consumer of industrial energy use. Carbon dioxide emissions due to fossil fuel use and cement production have increased by 60% since 1990. Substantial cement manufacturing has continued to rise steadily with surging economic growth, especially in emerging developing nations. A reduced ratio of clinker-to-cement content and an increase in clinker substitutes could mitigate environmental impacts from cement production. The use of cleaner fossil fuels, shifting from coal to renewable energy sources, is another way to mitigate impact. Cement production in Europe, which can reduce the clinker-to-cement ratio to 70%, results in a further CO2 savings of 4%, whereas cement production in the United States uses a 95% clinker-to-cement ratio.26
Recovering oxides from construction waste as an alternative raw material for the production of cement clinker
Published in Zoltán Bartha, Tekla Szép, Katalin Lipták, Dóra Szendi, Entrepreneurship in the Raw Materials Sector, 2022
Katarzyna Styk, Olga Świniarska
This paper aims to present alternative sources for the production of cement clinker. To make a proper introduction to the following research section, it is necessary to present the definition of cement as well as the clinker itself. According to the technical definition, cement is a hydraulic binding material obtained from mineral resources (marl, limestone, clay) by firing and subsequent grinding of the resulting sinter [3]. Cement clinker, on the other hand, is the basic ingredient in the production of cement and is responsible for its setting. It is produced by firing ingredients (most commonly calcium carbonate, aluminosilicates and other admixtures) at high temperatures in a rotary kiln [9, 10]. There are three basic types of clinker in the cement production process: barium - they are obtained from raw materials containing calcium and barium carbonates and aluminum silicates,aluminum - they are obtained from bauxite and calcium or from bauxite and limestone,portland - for the production of Portland cement; they are obtained from raw materials containing mainly calcium carbonate and aluminosilicates.
Energy use in industry, analysis and management of energy use
Published in Kornelis Blok, Evert Nieuwlaar, Introduction to Energy Analysis, 2020
Kornelis Blok, Evert Nieuwlaar
A cement manufacturer produces clinker (fuel use: 3.41 GJ/tonne clinker; electricity use: 0.266 GJ/tonne clinker). The clinker contains 65.0 mass% CaO obtained from the reaction of limestone (CaCO3). The clinker is used with other materials to form cement by grinding. The clinker/cement mass ratio is 0.75. The cement production step requires 0.360 GJ electricity per tonne cement. The combustion of fuel used by the cement manufacturer has a CO2 emission of 85.0 kg/GJ. The electricity used is produced with an efficiency of 35% and the fuel used for electricity production has the same CO2 emission as the fuel used by the cement manufacturer. Further data: molar masses: CaCO3: 100 kg/kmol; CaO: 56 kg/kmol and CO2: 44 kg/kmol. Calculate the specific energy consumption (primary energy use) for this cement in GJ/tonne cement.Calculate the CO2 emission per tonne cement.
Synergizing hydrogen and cement industries for Canada’s climate plan – case study
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2021
Rami S. El-Emam, Kamiel S. Gabriel
Cement production process has a significant environmental footprint. It is an energy intensive process that utilize extensive amounts of raw materials. Moreover, it is estimated to contribute with around 8% of global CO2 emissions (Olivier et al. 2016). Around 40% of CO2 emissions in cement production comes from the direct combustion of fuel to drive the clinker production process. The rest is produced from limestone decarbonation reaction to produce the primary component of clinker, calcium oxide. Clinker is an intermediate product in the cement production process and a main constituent of the final cement product. Portland cement contains around 90% clinker. It is produced by sintering finely ground raw material composed of mainly of limestone and clay and heated to around 1450C in the kiln. Clinker is ground to fine powder and mixed with small quantities of gypsum and other components forming cement. Calcium oxide is the primary oxide in clinker along with other silicon, aluminum, and iron oxides. Other indirect CO2 emissions is resulted from electric power consumption and transportation and shipment of products, raw materials, and fuels. This contributes another 10% of the overall emissions of the plant.
Environmental levels and human health risks of metals and PCDD/Fs near cement plants co-processing alternative fuels in Catalonia, NE Spain: a mini-review
Published in Journal of Environmental Science and Health, Part A, 2021
Joaquim Rovira, Montse Mari, Marta Schuhmacher, Jose L. Domingo
Cement is produced of clinker, gypsum and other additives. Furthermore, clinker is obtained by means of different crushed and homogenized raw materials, including limestone, clay and sands, which are calcinated at 1450 °C in a rotatory kiln. Inside the kiln, calcium carbonates (CaCO3), dissociate into carbon dioxide (CO2) and calcium oxide (CaO), which reacts with silicates (SiO2) to form calcium silicates (Ca2SiO5/Ca3SiO4).[3] Cement production process releases large amounts of CO2 to the atmosphere due the decarboxylation of raw material, as well as the consumption of fossil fuels in the kilns. The emission factors are between 0.9 and 1.2 tonnes of CO2 per tonne of clinker produced, approximately 50% of contribution of each emission (fuel and decarboxylation of raw material).[4]
Low carbon cement manufacturing in India by co-processing of alternative fuel and raw materials
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2019
Rahul Baidya, Sadhan Kumar Ghosh
Cement is one of the three main construction materials, which provides support for other related industries and fuels the economic growth (Song et al. 2016). The global construction sector approximately emitted 23% of total CO2 amounting to 5.7 billion tons during the year 2009 (Huang et al. 2017). The cement industry contributes approximately 5–8% of the global man-made carbon dioxide (CO2) emissions, thus becoming the second largest CO2 contributor in industry after power plants (Ishak and Hashim 2015; Kajaste and Hurme 2016). In the production of cement, the major raw material is limestone. It is processed in the kiln at a temperature of 1450°C during which the clinkers are formed. The clinkers are then blended with required additive materials as per the cement types. The final products are then finely ground.