Cement (original) (raw)
Related papers
Cement Based Materials a Path Towards Sustainable Development
Multidisciplinary Approach in Research Area (Volume-10), 2024
With an increasing awareness of environmental issues and their profound impact on human life, the pursuit of sustainable development has become paramount for humanity. In this context, the cement and concrete industry holds significant importance, given its contribution to CO2 emissions, consumption of raw materials, and energy. This paper delves into the potential of cement-based materials in fostering sustainable development. For the construction industry, adopting a framework centered on energy efficiency, material recycling, emission reduction, and durability is imperative. Not only does this approach yield environmental benefits, but it also enhances profitability and investment, ensuring a sustainable and resilient future for the construction sector. Keywords: Sustainable development, Cement-based materials, Environmental impact, Construction industry, Energy efficiency.
Introductory Chapter: Cement Industry
2021
Cement is a capital-intensive, energy-consuming and critical sector for the construction of nationwide infrastructure. The international cement industry, while constituting a limited share of the world's output has been rising at an increasing pace compared to the local demand in recent years. Attempts to protect the environment in developing countries, particularly Europe have forced cement manufacturing plants to migrate to countries with less strict environmental regulations. Along with consistently rising real prices, this has provided a trend for economic performance and environmental enforcement [1]. It is worth noting that cement is known to be one of the most important construction materials in the world. It is primarily used in the manufacture of concrete. Concrete is a combination of inert mineral aggregates such as sand, gravel, crushed stones and cement. Consumption and production of cement are directly connected to the building sector and thus to the general economic activity. Cement is one of the most developed goods in the world, due to its importance as a building material and the geographical availability of the main raw materials, i.e. limestone, cement is manufactured in almost all countries. The widespread development is also due to the comparatively low price and high density of cement, which, due to the relatively high costs, decreases ground transport. Export trade (excluding border-based plants) is typically limited relative to global production. Cement-based materials, such as concrete and mortars, are used in very significant amounts. For example, concrete production amounted to more than 10 billion tonnes in 2009. Cement plays an important role in terms of economic and social importance as it is necessary to develop and enhance infrastructure. This sector, on the other hand, is also a strong polluter. Cement processing emits 5-6% of the carbon dioxide emitted by human activity, accounting for around 4% of global warming. It may emit vast quantities of chronic chemical contaminants, such as dioxins and heavy metals and particulate matter. Energy use is also important. Cement production accounts for about 0.6% of all electricity generated in the United States. In the other hand, the chemistry driving the manufacture of cement and its applications can be very beneficial in solving these environmental concerns. Cement manufacturing is an extremely energy-intensive method of processing. The energy consumption is measured at around 2% of global primary energy consumption, or approximately 5% of total manufacturing energy consumption [2], regarding to the prevalent use of carbon-intensive fuels, e.g. coal, in the manufacture of clinkers. In addition to energy consumption, the clinker process also releases CO 2 as a result of the calcination process. Ecofys Energy and Climate and Berkeley National Laboratory therefore carried out an appraisal for the IEA Greenhouse Gas R&D Program on the role of the cement industry in the development of CO 2 and the options for lowering carbon dioxide emissions. This discuss the historical development and global distribution of cement production [3].
Trends and developments in green cement and concrete technology
International Journal of Sustainable Built Environment, 2012
The cement industry faces a number of challenges that include depleting fossil fuel reserves, scarcity of raw materials, perpetually increasing demand for cements and concretes, growing environmental concerns linked to climate change and an ailing world economy. Every tonne of Ordinary Portland Cement (OPC) that is produced releases on average a similar amount of CO 2 into the atmosphere, or in total roughly 6% of all man-made carbon emissions. Improved production methods and formulations that reduce or eliminate CO 2 emissions from the cement manufacturing process are thus high on the agenda. Emission reduction is also needed to counter the impacts on product cost of new regulations, green taxes and escalating fuel prices. In this regard, locally available minerals, recycled materials and (industry, agriculture and domestic) waste may be suitable for blending with OPC as substitute, or in some cases replacement, binders. Fly ash, Blast furnace slag and silica fumes are three well known examples of cement replacement materials that are in use today that, like OPC, have been documented and validated both in laboratory tests and in practice. The first is a by-product of coal combustion, the second of iron smelting and the third of electric arc furnace production of elemental silicon or ferro silicon alloys. This paper presents a concise review of the current state-of-the-art and standards underpinning the production and use of OPC-based cements and concretes. It outlines some of the emerging green alternatives and the benefits they offer. Many of these alternatives rely on technological advances that include energy-efficient, low carbon production methods, novel cement formulations, geopolymers, carbon negative cements and novel concrete products. Finally, the economics of cement production and the trends in the UK, US and the Gulf Cooperation Council (GCC) Region are presented, to help guide and inform future developments in cement production based on maximizing the value of carbon reduction.
Cement Manufacture and the Environment Part II: Environmental Challenges and Opportunities
Journal of Industrial Ecology, 2003
Construction materials account for a signi cant proportion of nonfuel materials ows throughout the industrialized world. Hydraulic (chie y portland) cement, the binding agent in concrete and most mortars, is an important construction material. Por tland cement is made primarily from nely ground clinker, a manufactured intermediate product that is composed predominantly of hydraulically active calcium silicate minerals formed through high-temperature burning of limestone and other materials in a kiln. This process typically requires approximately 3 to 6 million Btu (3.2 to 6.3 GJ) of energy and 1.7 tons of raw materials (chie y limestone) per ton (t) of clinker produced and is accompanied by signi cant emissions of, in particular, carbon dioxide (CO 2), but also nitrogen oxides, sulfur oxides, and particulates. The overall level of CO 2 output, about 1 ton/ton clinker, is almost equally contributed by the calcination of limestone and the combustion of fuels and makes the cement industry one of the top two manufacturing industry sources of this greenhouse gas. The enormous demand for cement and the large energy and raw material requirements of its manufacture allow the cement industry to consume a wide variety of waste raw materials and fuels and provide the industry with signi cant opportunities to symbiotically utilize large quantities of by-products of other industries. This article, the second in a two-par t series, summarizes some of the environmental challenges and opportunities facing the cement manufacturing industry. In the companion article, the chemistry, technology, raw materials, and energy requirements of cement manufacture were summarized. Because of the size and scope of the U.S. cement industry, the article relies primarily on data and practices from the United States.
An overview of energy savings measures for cement industries
Due the advances in the industrial processes, in which the cement industry is a major contributor, energy consumption and greenhouse gas emission has increased significantly. This paper reviews previous studies on energy saving, carbon dioxide emission reductions and the various technologies used to improve the energy efficiency in the cement industry. Energy efficiency measures for raw materials preparation, clinker production, products and feedstock changes, general energy efficiency measures, and finish grinding have been surveyed. It was found that the largest recorded amounts of thermal energy savings, electrical energy savings and emission reductions to date are 3.4 GJ/t, 35 kW h/t and 212.54 kgCO 2 /t, respectively.
Opportunities from Alternative Cementitious Materials
Computers and Concrete
An Accelerated Technology Implementation Team works toward enhancing twenty-first century concrete construction by encouraging new, more sustainable cements A major impetus for change in cement technology stems from the concrete industry's sustainability goals and the associated demand for reductions in the collective environmental impacts of the production of concrete. These impacts include immediate effects such as greenhouse gas (GHG) emissions, extraction of virgin materials (including water), and energy consumption, 1 and they can be compounded by premature repair or replacement as the result of inadequate durability. Alternative cementitious materials (ACMs) have the potential to provide major reductions in these impacts. ACM concretes can be produced with significantly lower GHG emissions and energy consumption than mixtures comprising portland cement. In some cases, the amount of water required in the concrete mixture is also significantly lower. Further, ACM concretes c...
2018
We first discuss cement production and special nomenclature used by cement industrialists in expressing the composition of their cement products. We reveal different types of cement products, their compositions, properties, and typical uses. Wherever possible, we tend to give reasons as to why a particular cement type is more suitable for a given purpose than other types. Cement manufacturing processes are associated with emissions of large quantities of greenhouse gases and environmental pollutants. We give below quantitative and qualitative analyses of environmental impact of cement manufacturing. Controlling pollution is a mandatory legal and social requirement pertinent to any industry. As cement industry is one of the biggest CO2 emitters, it is appropriate to discuss different ways andmeans of CO2 capture, which will be done next. Finally, we give an account of production of nanocement and advantages associated with nanocement. Nanofillers such as nanotitania, nanosilica, and ...
Secondary energy component in energy-saving processes of cement production
IOP Conference Series: Materials Science and Engineering, 2020
Problems of energy saving in the firing of raw sludge is an important factor in the long-term development of cement production. An integrated approach to the study of the properties of raw materials and additives makes it possible to find ways to save fuel and energy resources. Reducing the moisture content in the sludge by the use of plasticizing reagents is one way to solve the problem of reducing energy consumption during firing of sludge. Reducing the moisture content of raw sludge from 41% to 35.5% makes it possible to reduce energy consumption by 23.3 kilograms of equivalent fuel per ton of clinker. The most effective type and concentration of plasticizing reagent was selected. A decrease in the moisture content and an increase in flowability were studied on a model raw sludge based on kaolinite-montmorillonite clay, chalk and pyrite cinder – a coal -alkaline reagent (0.1 wt.%). The studied reagents were arranged in the following sequence according to the effectiveness of incr...
A critical review on energy use and savings in the cement industries
The cement sub-sector consumes approximately 12-15% of total industrial energy use. Therefore, a state of art review on the energy use and savings is necessary to identify energy wastage so that necessary measures could be implemented to reduce energy consumption in this sub-sector. In this paper energy use at different sections of cement industries, specific energy consumption, types of energy use, details of cement manufacturing processes, various energy savings measures were reviewed and presented. Various energy savings measures were critically analyzed considering amount of energy that can be saved along with the implementation cost. Amount of CO 2 reduction has been presented along with the payback period for different energy savings measures as well.