Ajay Kapur, CEO – Cement Business, Adani Group, explores India’s proactive measures, from embracing renewable energy and waste heat recovery to reducing clinker usage and innovatively repurposing industrial by-products, signaling a promising shift towards sustainable cement manufacturing.

Imagine a world without cement – it’s almost like picturing a skyline without its defining structures. As one of the most commonly used building materials, the manufacturing of cement faces significant challenges in decarbonising. Tackling this challenge goes beyond the ordinary, considering that the cement sector is a major player, contributing up to 7-8 per cent of global greenhouse gas emissions. The significance of this issue is particularly pronounced for India, as we currently hold the dual status of the world’s second-largest producer and consumer of cement. The production capacity of the Indian cement sector is poised to grow to more than 700 million tonnes (MT) over the next five years from around 570 MT now. Consumption on the other hand is also set to grow to 450 MT by 2027.
As the Indian economy expands and continues on this growth path to reach $5 trillion in GDP in the near term and emerge as the world’s third largest economy before the end of the current decade, the environmental challenges will also become more formidable.
Most large cement manufacturers in India have already committed to becoming carbon neutral sometime around the middle of this century and this is also going to contribute to India’s Net Zero ambition set for 2070. The road ahead for Indian cement manufacturers is very similar to what the energy sector faces. India’s economic turnaround that started in 1991 also brought home conversations around the rising and unprecedented levels of consumption of energy to fire up the economy, putting the country under the environmental spotlight, too. Cement production is not only energy intensive but also depends on natural mineral resources. The widespread adoption of well-understood and sustainable cement production practices has been a gradual process, gaining momentum over time. Today, the Indian cement sector is ready to meet sustainability challenges head-on through a whole range of measures that covers the entire value chain in cement manufacturing, leading all the way to increasing the share of green cement on the demand side.

Alternative fuel and raw materials
Being an energy-intensive sector, cement manufacturers have started investing in cleaner sources of energy like solar and wind as captive generation units to run their plants. This shift in no small measure is supported by the falling cost of renewable energy India. Between 2010 and now, the cost of solar modules in India have dropped by more than 80 per cent, making it one of the most sought after sources of clean energy for large industrial units including cement. Similar efforts are also on to move finished cement, packed and bulk on more sustainable or green logistics like soya extract-based biofuel powered shipping. Bulk terminals and grinding units along India’s long coastline can enable the movement of clinker and cement through the sea route at the lowest possible cost.
The share of green energy is further enhanced through investments in Waste Heat Recovery Systems (WHRS). These systems not only adhere to the principles of the circular economy but also result in fossil fuels savings. This not only nurtures a more cost-efficient process but also directly impacts the bottom line.
According to the Ministry of New and Renewable Energy (MNRE), the Indian cement Industry has the highest potential to adopt WHRS as an alternative to conventional sources of energy. WHRS installations will continue to grow along with the increase in capacity to manufacture cement, bringing it close to 1.3 GW at current production capacity levels. It is estimated that WHRS would help replace the energy requirement equivalent to 8.6 million tonnes of coal, resulting in emissions savings of 12.8 million tonnes of CO2 by the Indian cement manufacturers.
Cement manufacturers are also cutting down on the ‘clinker factor’ by replacing them with industrial by-products without compromising the quality (strength) of the cement. Cutting down the clinker factor offers two immediate benefits. One, it reduces energy consumption because clinker is produced at ~1400°C (from limestone etc.,) and two, it also softens the environmental impact of by-products like flyash, slag and silica fumes. Manufacturing a tonne of Ordinary Portland cement also releases around 800 kg of CO2. Investments are also made in recycling massive quantities of municipal waste into Refuse Derived Fuel or RDF through its pre- and co-processing facilities, which is then used as energy to run cement kilns. The impact of producing and using RDF not only saves on energy from conventional sources but also helps large cities manage municipal waste in a safe manner. Mega cities like Mumbai are now working with cement companies to manage municipal waste through a symbiotic relationship that benefits manufacturers and city administrators.
Red mud, a waste derived from aluminium production, is also now used in the cement manufacturing process as an alternative raw material. Again, this helps build a circular economy through utilisation of aluminium industry’s by-products in an environmentally sound manner. Other large industrial sectors like pharmaceuticals also tapped for zero residue of their process waste and ETP sludge. Similarly cement manufacturers are also able to process hazardous wastes released by the automobile and automobile ancillary sector such as chromium, zinc and paint sludge, oil residue and cotton waste.
Water management is yet another area that is making cement manufacturing in India more sustainable. Apart from becoming water positive (returning more water than what is consumed) from an operations point of view, a lot is also being done under the larger banner of CSR where cement manufacturers are now active participants in water conservation projects, working along with local rural communities including farmers. Large cement manufacturers in India are also working on conserving biodiversity in their areas of operations including large afforestation projects, which helps in strengthening the water table.

Conclusion
India today has a very robust legislative mechanism to ensure that industrial sectors like cement abide by environmental laws. But cement manufacturers, recognising the growing environmental consciousness among consumers, are actively pursuing higher benchmarks to minimise burden on environmental damage. With the growing consumer centricity that has moved cement from being a commodity to a branded consumer product, manufacturers are now able to offer sustainability as part of the brand value and appeal. Green cement as a product in India is still in its nascent stage with a miniscule share in the overall market. It is expected to grow in coming years as sustainability is an important factor for today’s buyers.
Today’s well-informed consumers also expect manufacturers to play a more responsible role in protecting the environment through sustainable manufacturing practices. The transformation of the Indian cement sector has only begun.

ABOUT THE AUTHOR:
Ajay Kapur, CEO – Cement Business, Adani Group has over 30 years of expertise in the cement, construction, power and heavy metals sector. He has been extensively involved in several business forums, such as CII, FICCI, and ASSOCHAM.