How does the cement industry view sustainability?
Cement production is an energy and material-intensive process. The primary raw material is limestone, which is first mined, crushed and ground to raw meal and then heated to a temperature as high as ~1400 °C in a cement kiln. The hot material is then cooled down to form clinker, an intermediate product. In this chemical conversion process, when limestone (CaCO3) is converted to lime (CaO), significant amount of Carbon dioxide (CO2) is emitted. CO2 is also emitted through fossil fuel combustion in cement manufacturing. Thus, the cement sector is also known as emission-intensive industry contributing almost 7% of global GHG emissions. The source of carbon in the whole process is calcination of limestone, and usage of fuel in horizontal kiln (Scope 1), use of electricity (scope 2, when sourced from state utilities) and transportation of raw materials and finished product by road (scope 3).
Thus, for the cement industry, sustainability would necessarily mean reducing its carbon emissions. Without working on its decarbonisation strategy, no cement company can call itself’sustainable’. As a part of its decarbonisation strategy, cement companies primarily focus on substituting clinker with slag or flyash, thus contributing to a circular economy. They also consider using alternative fuels, switching to renewable energy and optimising their energy efficiency as other levers for reducing CO2 emissions.
The cement manufacturing process has an impact on air emissions, biodiversity, and water, though not as significantly as on climate. Thus companies work towards limiting their impact on overall ecosystem. In most manufacturing units, spent mines are used as a huge water reservoir which stores rainwater, which is later consumed by plant itself or nearby communities around, reducing the burden on freshwater sources.
To improve sustainability, would the cement industry adopt a new business model?
Given the durability, strength and economic of cement along with availability of limestone, cement and concrete, would likely to remain the construction material of choice globally. Currently, there is no substitute for cement. However, in future, the scenario may change considering the visible impacts of climate change and increased pressure on industry to decarbonise the sector. Companies have to think strategically about a new business model or diversified business verticals.
A new business model that focuses on producing cement with the least amount of clinker possible will undoubtedly help companies improve their sustainability performance. This can be done through product innovation and developing new products such as Geopolymer cement, Limestone Calcined Clay Cement (LC3) using little or no clinker. These days, almost all companies are working towards this.
What one change would you make to your company’s operations to make it more sustainable?
JSW Cement has already leveraged the option of clinker substitution, quite significantly, by maximising the use of slag in cement, which has helped the company to achieve the lowest specific emissions not only in India but, possibly in the world also. One change which we see can further accelerate our decarbonisation journey is transition towards renewable and alternative sources of energy. This has two aspects: one is replacing our coal requirement with industrial/municipal waste or biomass waste. This will certainly help us reduce our net CO2 emissions. The second aspect is to use more green energy (generated through solar plant, or wind farms) or use clean energy through waste heat recovery method.