Cement; the Most Destructive Components to the Environment in Bangladesh
To cope with the ever-growing world population, the worldwide development of infrastructure and construction is driving a massive need for concrete. The most frequently utilize substance on the earth is cement, second only to water.
According to COLIN B. BROWN,s research, each person on the planet utilizes three tons of concrete every year. Most construction projects require concrete, which consists mainly of cement, aggregates, and water. Therefore, the most widely used construction material is cement, with around 4 billion tons per year (Gagg, C.R. 2014).
According to ‘Statista‘ by a significant extent, China produces the most cement in the world, with an expected 2.2 billion metric tons in 2020, followed by India with 340 million metric tons. China produces over half of the world’s cement.
Cement production in the world predicts to rise from 3.27 billion metric tons in 2010 to 4.83 billion metric tons by 2030. Among them, in Bangladesh, cement consumption was estimated at around 27.10 million tons last year. According to Masud Khan, Ex CEO of Crown Cement Group, demand expects to grow at an 8 to 10% annual rate over the next five years.
The demand for cement is increasing in Bangladesh because semi-urban areas are becoming cities and rural areas are becoming semi-urban areas,” says Fahima Shahadat, Ex head of the infrastructure and technical services at LafargeHolcim Bangladesh Limited.
She claims that high-rise buildings are being built across the country and, for that, need more high-quality, durable cement. According to industry experts, infrastructure projects account for 20 to 22% of cement consumption, 25% for the industrial sector, and the rest for retail.
Based on the 2015 World Bank analysis, the country experienced faster urbanization than South Asia between 2000 and 2010. There are 76 cement production companies in Bangladesh, with 45 big and small-scale companies producing cement. The effective capacity of the operating plants in 2017 was about 50.20 million tons. By 2019, the total cement manufacturing capacity expects to exceed 80 million tons.
Generally, cement often produces by combusting traditional resources like stone and clinker and industrial byproducts such as fly ash and slag. In Bangladesh, two companies have clinker production facilities at its plants. One is the government-owned company named Chhatak Cement Factory.
The other is the Public limited company that is Lafarge Surma Cement Ltd. The Lafarge Surma Ltd produces 1.3 to 1.4 million tons of clinker per year, meeting about 10% of global demand (The Daily Star, 2018). Besides, manufacturing cement components consumes a lot of energy, as it needs to raise the temperature to 1450 °C, which increases the manufacturing cost of cement. The cement industry in Bangladesh consumes 2.90% of the country’s total primary energy.
Furthermore, it also reported that cement production is associated with an increased in carbon dioxide (𝐶𝑂2) emissions, which contributes to Global Warming and Climate change. Carbon dioxide (𝐶𝑂2) is produced as a byproduct of clinker synthesis, a step in the cement manufacturing process that burns calcium carbonate (𝐶𝑎𝐶𝑂3) and converts it into lime (𝐶𝑎𝑂), the main cement component.
Carbon dioxide (𝐶𝑂2) is also released from burning fossil fuels (Coal, Petrol, Diesel, etc.) during the cement manufacturing process. On the other hand, 𝐶𝑂2 produces from fossil fuels gives special consideration in fossil fuel emission estimates. Each ton of cement produces roughly 900 kg of 𝐶𝑂2, with an estimated annual production of nearly 3.5 billion tons of cement.
This amount is equivalent to more than 3 billion tons of 𝐶𝑂2 per year, and only in Bangladesh, the amount would be approximately 25 million tons. As a result, the cement industry is responsible for roughly 8% of total 𝐶𝑂2 emissions. The Greenhouse effect and Acid rain are caused by not just 𝐶𝑂2, but also 𝑆𝑂2 (sulfur dioxide) and N2O (nitrous oxides) by cement manufacturers.
In Bangladesh, 𝐶𝑂2 emissions per capita are 0.47 tons per person (based on a survey of 2016 population of 157,977,153), an increase of about 0.02 from the previous year’s estimate of 0.46 tons per person; that represents a 3.4% increase in 𝐶𝑂2 emissions per capita.
Bangladesh produced 74,476,230 tons of fossil’s 𝐶𝑂2 in 2016. Carbon dioxide (𝐶𝑂2) emissions increased by 4.50% over the previous year, an increase of 3,210,348 tons over 2015, when 𝐶𝑂2 emissions were 71,265,882 tons.
As the 𝐶𝑂2 increase in the atmosphere, it will contribute to the greenhouse effect. Greenhouse gas emissions have a wide range of environmental and health consequences. It contributes to respiratory problems caused by Smog and Air pollution and climate change by trapping heat.
Other implications of climate change produced by greenhouse gases include extreme weather, food supply shortages, and increasing wildfires. Due to the greenhouse effect, Western Antarctica is losing 159 billion tons of ice a year, which could cause sea levels to rise by 0.5 mm per year. According to the IPCC’s Fifth Assessment Report, the Bay of Bengal’s sea level increases at a pace of 1.5 millimeters per year.
Due to its low elevation, Bangladesh, bordering on the south by the Bay of Bengal, would be immediately affected by Sea level rise. If the seawater level rises 45 cm, Bangladesh will permanently lose 15600 square kilometers of its coastal land.
If it rises one meter, about 14000-30,000 square kilometers of it land will submerge, putting more than 20% of Bangladesh underwater. According to scientists, rising sea levels would drown 17% of Bangladesh’s land area in the next 40 years, displacing 18 million people from its coastal zones by 2050.
Several types of research are going on to overcome this situation and minimize cement consumption by recycling waste from various sources, including construction and demolition debris and waste from various industries, including steel, agriculture, glass, rubber, etc.
These wastes are plentiful in some places, possibly utilizing in concrete production on a large scale. Using waste products in the cement replacement and construction industry will reduce the emission of 𝐶𝑂2 in the environment and help us develop a proper waste management system across the country.
Reference:
TheWorldBank. (2015). Leveraging Urbanization in Bangladesh.
The Daily Star. (2018). Cement consumption to grow steadily | The Daily Star.
