Circularity — the practice of bringing used resources back into the supply chain rather than consigning them to landfill — may be pursued by many companies striving for sustainable operations and lower carbon footprint, but India’s JSW Cement was founded on that premise.
“JSW Cement started in 2009 with a problem statement: What to do with the huge deposit of Blast Furnace slag from JSW Steel manufacturing plants,” explained Manoj Rustagi to an audience of ABB India executives at the company’s inaugural Dialogue 4.0 virtual session — Deep-Dive into the Cement Industry,' Case-study on Decarbonization.
As Chief Sustainability & Innovation officer at India-based JSW Cement Limited, Rustagi pursues many of the strategies and principles that also drive ABB. Passionate about sustainable growth as driven by cutting-edge technologies, he has contributed to many strategic initiatives that continue to shape positive change in the cement and steel sectors over the 29 years of his professional career.
Today, cement remains one of the hardest to abate sectors of the global economy, contributing some 7% of total global CO2 emissions, which makes it the fifth biggest slice of the emissions pie chart, after power generation and transport (which together make up 50% of global emissions), agriculture and steel production.
Cement is hard to abate, explained Rustagi, because the substance that has long been at the heart of cement is produced by heating calcium carbonate — limestone — and other ingredients to around 1,400 degrees centigrade. This calcination of limestone, which results in a product known as clinker, gives off processed CO2 at a rate of 60% of traditional cement’s total emissions profile — and that does not include emissions attributable to thermal & electrical energy.
Calcination: who needs it?
Although increasing energy productivity and finding alternative fuels to the coal and pet coke (derived from petroleum refining) traditionally used to heat the cement-making kilns are important levers for reducing CO2 emissions from cement production, developing other alternative materials and cementitious materials that can supplement or totally replace limestone-based clinker are key to substantially reducing the CO2 emissions of cement.
JSW Cement’s initiative to grind blast furnace slag coming from steel plants and combine it with ground clinker to produce blended cement is one of the main reasons for the company’s world-beating low carbon footprint. Global Cement and Concrete Association (GCCA) figures show that JSW Cement has only one-third the carbon emission intensity when compared to the global average of cement manufacturers.
The two outstanding qualities of blast-furnace slag, says Rustagi, are that it is recycled material, but mainly that “it has already been calcined, so there is no process emission and that takes care of a chunk of CO2 emissions”.
His favorite comparative graphs of data show that “In the past 8-9 years JSW Cement has grown fourfold in terms of sales volume. And at the same time, our carbon emissions intensity has more than halved. So, while there is average growth in volume at a rate of around 20% per annum, but at the same time, there is average reduction in specific carbon intensity of around 12-13% per annum.
Both curves are important since the demand for this strong, durable, comparatively inexpensive building material is increasing, and the industry’s CO2 output must continually be reduced. Statista.com forecasts that demand for cement will grow at a rate of 2.9% per annum, at least until 2025. That is, demand of 4.2 billion metric tonnes in the 2022 financial year will grow to 4.71 bmt/a in 2025.
Governments can favor change
Like most proponents of greater sustainability for hard-to-abate industries, Rustagi believes government has a role to play in incentivizing change. He points out that India does not yet have carbon pricing or trading mechanisms which would help value the improvements companies want to make. He said that India needs public policy for “Sustainable Procurement” specifically for building materials with lower embodied carbon. And although the Indian government, perhaps realistically, pushed its net-zero ambitions out to 2070 at the COP26 summit, the JSW Group is pursuing net-zero carbon emissions by 2050, in line with many other global cement companies.
He adds that financing and funding for bringing effective Carbon Capture Utilization and Storage (CCUS) to market is also critical. These capital-intensive processes will be needed to deal with the unabatable aspects of processes such as cement and steel production. “And the second thing,” said Rustagi, “is to develop use cases for that captured carbon because the volumes are going to be so large.”
JSW Cement is also working on disruptive technologies among the cementitious material possibilities, such as geopolymer cement and geopolymer concrete, which can be activated to achieve strength equal to or better than traditional cement and may in time entirely replace clinker.
Another area of research is in identifying different recycled materials that can supplement clinker in the cementitious mix. “We’re working with a laboratory based in Duisburg in Germany,” reveals Rustagi, “on using steel slag, for example, which is different from the blast-furnace slag. We have started using it as an alternative raw material in clinker plant, and we want to increase that percentage over time.”
Scheduling, prefabricating, and sensor checking cement
Rustagi’s vision for JSW Cement dovetails with ABB’s expertise in automation and digitalization to increase efficiencies, thereby incrementally increasing production and reducing emissions in line with demand for cement and climate ambitions.
The company’s “wishlist” for achieving “technological maturity from a project execution point of view” includes advanced scheduling software and IoT devices that enable just-in-time material ordering and cost-risk assessments; wireless sensors for construction monitoring; 3D visualization and laser scanning of structures to reduce construction defects; and construction robotics to realize precision manufacturing of prefabricated materials and modular construction systems.
Rustagi’s insight-packed presentation thus concluded on future pathways for Dialogue 4.0 between JSW Cement and ABB and heralded a constructive future.