The green cement industry and its role in reducing the industrial carbon footprint
Green cement industry and its role in reducing the industrial carbon footprint
Today, climate change has become one of the biggest challenges facing humanity, given the diverse impacts it has on all aspects of our lives. This imposes a number of new challenges on humanity at the environmental, economic and societal levels. Therefore, it is not surprising that reality forces us to shift our activities to sustainability, especially industrial activities, the forefront of which is the building materials industry.
Among the various building materials, concrete stands out; Because it is the most used material – after water – in the world, as humanity uses up to 14 billion cubic meters of concrete every year in various types of construction and applications.
To clarify the magnitude of the previous number, suffice it to say that this quantity of concrete could cover the entire area of England and half the area of Wales with a layer of concrete, ten centimeters thick. This quantity could also cover the entire state of New York with the same thickness.
Concrete is considered the most important construction material in the modern era. Because it plays a crucial role in the construction and development of infrastructure and buildings around the world, because of the exceptional structural strength it provides, and because it is resistant to weather factors and corrosion. This makes it the ideal material for various construction works, from residential buildings to bridges and roads.
In addition, concrete is easy to pour, which makes it suitable for various designs and engineering needs, making it a popular choice among engineers. Therefore, the importance of concrete in promoting sustainable development and achieving structural stability in the modern world cannot be denied.
But concrete production releases carbon dioxide (CO2), which is the most prominent greenhouse gas that leads to climate change. Concrete-related emissions come primarily from the production of Portland cement, up to 90%, since this type of cement is responsible for binding concrete components together. The Portland cement industry represents between 7% and 8% of the world’s direct carbon dioxide emissions.
Therefore, the scientific and industrial community has become interested in finding low-carbon cement alternatives, in addition to shifting this industry to sustainability. Because this may achieve multiple benefits, not only on the environmental side, but also on the economic side, and from here the term green cement arose.
A complex and extended issue
People have been using concrete for more than 2,000 years, mixing gravel, sand, cement, water, and sometimes some synthetic chemicals. Over the centuries, human use of concrete has increased, and at the present time the European Union, for example, uses concrete at a rate of up to two tons per person annually, of which 325 kg is cement, which is an indication of the extent of our great dependence on both concrete and cement.
Cement production is an energy-intensive process. Therefore, it is responsible for producing large amounts of greenhouse gas emissions. The cement industry requires this large amount of energy to heat limestone and other raw materials in kilns, and these energy needs are often met by burning coal or other fossil alternatives.
The problem here – in general – is not only in the emissions resulting from burning coal or fossil fuels, but also in the limestone, approximately half of which is lost during production processes, in the form of a mixture of calcium oxide and carbon dioxide. For every ton of Portland cement produced, between 600 and 900 kg of carbon dioxide are released into the atmosphere.
Many sectors depend on cement, which means that the main challenge facing this industry is reducing carbon dioxide emissions on the one hand, and meeting the increasing global need on the other hand, which is an equation that is difficult to balance. Therefore, low-carbon cement production – along with the development of new technologies – must be adopted on a global scale. To meet the required infrastructure needs, especially in developing countries.
Low-Carbon Alternatives
Other ways to reducecarbon footprintfor concrete include using fly ash (a byproduct of burning coal in power plants) or slag (a byproduct of steelmaking), to partially replace portland cement in the concrete mixture.
Despite the environmental feasibility of the above, these methods are not considered appropriate in the long term. Because these alternative materials to cement will also decline with the growth of low-carbon technologies in general, the world is now trying to get rid of coal for energy production, while the steel industry is trying to increase reliance on recycling, instead of production using virgin materials. Which means that ash and slag may not be sufficiently available in the future.
Current strategies for decarbonizing cement and concrete rely largely on the use of carbon capture and storage (CCS) technology to deal with unavoidable emissions during cement production processes.
Therefore, when we say low-carbon cement production, we do not necessarily mean replacing all current cement production technologies, but rather this can include factories that implement carbon capture and storage technologies.
In Norway – for example – the Heidelberg Cement Company is building a carbon capture and storage unit on an industrial scale in one of its facilities in this European country. In order to capture and store about 400 thousand tons of carbon dioxide annually, representing 50% of the total current factory emissions.
Despite the solutions provided by carbon capture and storage technology, we find some obstacles represented by the large investment cost, which not all cement manufacturers may be able to bear, in addition to the fact that storing carbon in the earth’s layers requires some geological characteristics, the availability of which cannot be guaranteed in all cement production sites.
On the other hand, some believe that the solution to transforming the cement industry to sustainability lies in the presence of a binding legislative framework for cement manufacturers, ensuring the reduction of their carbon emissions. Perhaps the most prominent example of this is the European Union Emissions Trading System (EU ETS). It is a system that sets the ceiling for emissions in various industrial sectors, so that factories that exceed this ceiling pay fines for their excessive pollution, and the revenues collected by this system are then used to finance green transformation projects.
What is striking here is that the aforementioned emissions trading system did not succeed in reducing the emissions of the cement industry in Europe – significantly – in the past decade, which indicates the presence of a group of other factors that must be taken into consideration.
Despite the good profits made by the cement industry, there is not enough investment – on a large scale – in clean technologies and the transition to sustainable use of materials. This means there is a need for greater financial incentives that push companies to invest in low-carbon solutions for cement production.
Other ways to reduce the carbon footprint of concrete include using fly ash (“ash” (a byproduct of burning coal in power plants) or slag (a byproduct of steelmaking) to partially replace portland cement in the concrete mixture.
Despite the environmental feasibility of the above, these methods are not considered appropriate in the long term. Because these alternative materials to cement will also decline with the growth of low-carbon technologies in general, the world is now trying to get rid of coal for energy production, while the steel industry is trying to increase reliance on recycling, instead of production using virgin materials. Which means that ash and slag may not be sufficiently available in the future.
Current strategies for decarbonizing cement and concrete rely largely on the use of carbon capture and storage (CCS) technology to deal with unavoidable emissions during cement production processes.
Therefore, when we say low-carbon cement production, we do not necessarily mean replacing all current cement production technologies, but rather this can include factories that apply carbon capture and storage technologies.
In Norway – for example – the Heidelberg Cement Company is building a carbon capture and storage unit on an industrial scale in one of its facilities in this European country. In order to capture and store about 400 thousand tons of carbon dioxide annually, representing 50% of the total current factory emissions.
Despite the solutions provided by carbon capture and storage technology, we find some obstacles represented by the large investment cost, which not all cement manufacturers may be able to bear, in addition to the fact that storing carbon in the earth’s layers requires some geological characteristics, the availability of which cannot be guaranteed in all cement production sites.
On the other hand, some believe that the solution to transforming the cement industry to sustainability lies in the presence of a binding legislative framework for cement manufacturers, ensuring the reduction of their carbon emissions. Perhaps the most prominent example of this is the European Union Emissions Trading System (EU ETS). It is a system that sets the ceiling for emissions in various industrial sectors, so that factories that exceed this ceiling pay fines for their excessive pollution, and the revenues collected by this system are then used to finance green transformation projects.
What is striking here is that the aforementioned emissions trading system did not succeed in reducing the emissions of the cement industry in Europe – significantly – in the past decade, which indicates the presence of a group of other factors that must be taken into consideration.
Despite the good profits made by the cement industry, there is not enough investment – on a large scale – in clean technologies and the transition to sustainable use of materials. This means that there is a need for greater financial incentives that push companies to invest in low-carbon solutions for cement production.
Other contributing factors
In this context, we should not ignore the role of facility design and material selection that is no less important than carbon reduction techniques in the cement industry. Good design and more efficient use of materials, in addition to choosing low-carbon materials during the building life cycle; All of these factors contribute – in one way or another – to reducing the carbon footprint resulting from the construction sector. Sustainable design alone can easily save up to 20% of emissions generated by this sector.
Here comes the role of governments in various countries to adopt regulatory frameworks that require companies to use low-carbon alternatives to cement, while setting standard specifications for construction methods and designs, ensuring that the efficiency of resource consumption is taken into account, and the most sustainable is chosen.
But the question here is: Can all cement in the future be transformed into low-carbon “green” cement? The answer to this question depends on how we define “low carbon.” Because this will play a very important role in how this is translated into practice in industry.
In conclusion, we must point out that there is still a long way to go to transform thecement and concrete industry to sustainability, which requires cooperation on a local and global scale. To provide the necessary incentives for the pioneers of this industry to shift their activities to sustainability, and to provide the necessary investments to develop more advanced and environmentally friendly technologies, while truly adopting the foundations of sustainable design, and thinking creatively about new alternatives to traditional building materials.
