Researchers at India's top three IITs are working on a cement producing technique that is sensitive to the environment as well as the economy. Sanchayan Bhattacharjee reports
Professors at IIT-Delhi, IIT-Bombay and IIT-Madras along with Technology and Action for Rural Development (TARA), a social enterprise, have come up with a Limestone Calcined Clay Cement (LC3) which is significantly less harmful to the environment. According to their research paper, production of LC3 will reduce the clinker factors down to 40 per cent and emissions by 50 per cent as compared to Ordinary Portland Cement. Clinker is a combination of limestone, clay and other minerals which is extensively used during cement production. The average cement available in the market consists of 74 percent clinker.
Reduction of clinker is not the only benefit. “A lower quality of limestone and clay can now be used to manufacture this cement. This means that the limestone mines will have a longer life,” says Shashank Bishnoi, professor, Department of Civil Engineering, IIT Delhi.
In addition to being energy intensive and resource efficient, LC3 is also expected to save money. “In terms of capital investment, there will be huge savings. While a new clinker based factory will cost hundreds of millions of rupees, a LC3 plant will cost much less,” explains Bishnoi. Apart from these savings, even the production process will be economical depending on the location and raw materials available.
Currently, more than 30 tons of LC3 has been produced and a building has been constructed near Jhansi in Uttar Pradesh, to check the feasibility of the cement in constructions. The objective is to secure standardisation for the cement from the Bureau of Indian Standards. “The strength of the cement is easy to test, what takes time is checking the durability. We have to ensure that buildings constructed using this cement can withstand different geographic and climatic conditions,” says Bishnoi. As of now the project is a mix of basic and applied research. “While the IITs will focus on standardising the product, we will engage in discussions with the cement and construction industry to make them understand the need and benefits of LC3,” says Soumen Maity, general manager, TARA.
Although securing a standard for cement production is an arduous process, the benefits of this innovation are enormous. “The capacity of the cement industry doubles every decade. So in future, even if they take the LC3 production as a fraction of this expansion, the cumulative economic and environmental benefits will be enormous,” signs off Bishnoi.
India is the second largest consumer of cement in the world. According to a study conducted by the Confederation of Indian Industry (CII), the per capita cement consumption in the country is expected to touch 400 kg in 2015 as against 185 kg today.