Sustainable Practices

Turning waste heat into power to reduce cement production costs

By Neeraj Akhoury, CEO India, LafargeHolcim, and CEO and Managing Director, Ambuja Cements

Sustainability solutions like waste heat recovery systems (WHRSs) are in tune with the times. It is yet another green solution that can save money too.

By the time these words reach the printer, we would have hopefully crossed the peak of the second wave of the pandemic. Let us also hope that we have learned some hard lessons as we pick up our strength once again and begin to see beyond the immediate challenges. In a matter of weeks, India’s economic outlook for the rest of the year has moved from a low double digit to single digit. Considering what we have been through for more than a year now, it is clear that we have a lot of work to do to ensure that economic recovery does not lose any more steam.

One of the key drivers for this expected recovery will be large public spending on major infrastructure projects such as roads and railways, supplemented by similar investments in fresh production capacities in the private sector. Core sectors like steel, energy and cement should be among the key beneficiaries of the heightened economic activity in the country. As the world’s second largest cement and steel producing country, India’s growth opportunities must be managed with a sense of responsibility by ensuring that they are environmentally sustainable too. There is no shortage of opportunities in this regard. For example, according to the Cement Sustainability Initiative, a global consortium of over 100 cement manufacturers from almost 25 countries, the potential CO2 emission savings in the sector can be as high as 1 gigatonne per year by 2030, that is, around a third of the annual CO2 emissions of a country like India.

Over the past decade or so, large cement producers in India have made substantial investments to create a sustainable cement industry. This includes investing in innovations and R&D to ensure that more green building materials are in the pipeline, redesigning the manufacturing process with greener solutions such as renewable energy, and creating a circular economy by promoting recycling, reuse, etc. Further, the United Nations Energy Programme has declared 2021-30 as the UN Decade on Ecosystem Restoration, which provides ample time for energy-intensive sectors like cement to turn their focus inwards and increase investments in sustainable manufacturing practices.

Energy is one area that offers potential for investments in sustainable solutions, which will lower the dependence on fossil fuel-based capacity generation, increase the use of renewable energy sources and recycle process-based wastes for a new source of energy. Given that energy accounts for nearly a third of the operating costs of cement manufacturing, the potential for cost savings through green energy is immense. WHRS is one such solution that is gaining significant traction in India’s cement sector. WHRS converts the waste heat available during clinker production into an economical source of power, thus helping in reducing the overall operating cost for manufacturers. The per unit cost of energy from WHRS can be as low as 50 paise against Rs 6-Rs 8 per unit cost of grid (thermal) power.

While the initial investment in WHRS can be twice as much as that for conventional energy sources, its long-term benefits clearly outweigh the benefits of conventional power. Further, a typical cement plant produces enough heat to cover a third of its overall power needs using WHRS. Thus, WHRS along with other clean energy sources can play a vital role in creating a more sustainable cement sector in the country.

Unlike in the past, today’s cement manufacturers, particularly the big brands, are addressing a more progressive market with enlightened consumers who are willing to be a part of the solution by supporting green building materials. This presents an opportunity for cement and other building material manufacturers to increase their role in the Green Building Movement within the commercial and industrial construction industry. In the coming few years, the market for green building materials will expand to justify big investments in sustainable manufacturing practices. Large players in the construction sector are looking at downstream suppliers of building materials to procure products that have lower carbon footprints. Thus, manufacturing products that have a low carbon footprint through solutions like WHRS will not be a wasted effort. But the first steps must be taken by manufacturers.




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