Economy & Market
Being Proactive about Sustainability
Hard-hitting facts such as scarcity and price hike of fossil fuels and challenges of waste management warn of difficult times ahead, unless players strive to increase the capacity of Waste Heat Recovery Systems to meet energy requirements.
Waste heat recovery has long been the base standard for setting up cement manufacturing units. In China, a cement kiln will not get an official sign-off unless it has waste heat recovery systems. In Europe, any industry requiring large quantities of heat input for manufacturing must have waste heat recovery as a natural corollary, and sometimes its use could be extended to providing heat input to the neighbourhood and community for simple needs such as room and water heating systems.
The economics of Waste Heat Recovery Systems (WHRS) is preceded by sustainability concerns, as cement manufacturing in kilns continues to produce 8 per cent of the global greenhouse gas (GHG) emissions. The conversion of limestone to clinker is where the bulk of the heat energy is expended. However, this bulk of heat energy that is generated in six-stage preheater kilns by burning of any fossil fuel input actually gets wasted as shown in the pie-chart Fig 1, and only 58 per cent is used in the conversion process yielding clinker.
Theoretically 710 Kcal needs to be generated to convert 1 kg of clinker, out of which actual conversion process would need 410 Kcal, the rest ending up as losses, which can be recovered. In reality, the Indian cement industry average is 744 Kcal of heat input for producing 1 kg of clinker, which means the actual losses are even more than the theoretical possibility.
Out of the total generated heat there are some unavoidable losses, that include radiation loss, loss for evaporation of residual moisture in fine coal and raw meal and some part of heat going with clinker from cooler. The balance loss in pre-heater exhaust gases and the cooler exhaust gases are completely recoverable through WHRS.
electricity consumption to make a significant dent in the
energy intake the industry
Let us look at some statistics from the Indian cement industry. On an average, Indian cement plants require electrical power of 20 billion kWh per year. The coal needed for generating this much power accounts to 32 million tonnes per year. A significant portion of this power could be replaced by the WHRS that will use waste heat from the kilns to generate electricity.
In sustainability terms, this is equivalent to replacing a large component of the 32 million tonnes of coal to be otherwise burnt for producing electricity. WHRS are also very stable systems that operate on the Rankine cycle and it provides an avenue for utilising waste water from the process as well.
Balancing the investments
Let us now see the economics of putting up a captive power generating unit versus putting up a WHRS. The capital investment for WHRS is high at Rs 8 cr per MW going by the current costs, whereas the CPP units can come at Rs 4.5 cr per MW. However, the project Internal Rate of Return (IRR) would be very different as the cost of generation would be as low as Rs 0.40 per unit for the former while Rs 4.5 per unit for the latter, which given the current trajectory of fossil fuel prices is already under severe stress of upward correction. It is only the initial cost that continues to act as a deterrent for putting up a waste heat recovery unit.
The Indian cement industry must act responsibly and move quickly to put in investments that could raise the waste heat recovery installed capacity to cross the minimum threshold of 25 per cent of electricity consumption. That will still be far from the 20 billion KWhr of total electricity consumption by the industry.
The other area of concern is the price trajectory of fossil fuels, which would continue to move northwards. WHRS is one of the simpler ways of insulating the industry from the vagaries of future price increases.
Thus WHRS could be the natural hedge to fossil fuel price increases for a substantial portion of the electrical consumption. As matters stand today most WHRS would be the highest IRR projects that the industry as an ensemble can think of
-Procyon Mukherjee
Jignesh Kundaria, Director and CEO, Fornnax Technology
India is simultaneously grappling with two crises: a mounting waste emergency and an urgent need to decarbonise its most carbon-intensive industries. The cement sector, the second-largest in the world and the backbone of the nation’s infrastructure ambitions, sits at the centre of both. It consumes enormous quantities of fossil fuel, and it has the technical capacity to consume something else entirely: the waste our cities cannot get rid of.
According to CPCB and NITI Aayog projections, India generates approximately 62.4 million tonnes of municipal solid waste annually, with that figure expected to reach 165 million tonnes by 2030. Much of this waste is energy-rich and non-recyclable. At the same time, cement kilns operate at material temperatures of approximately 1,450 degrees Celsius, with gas temperatures reaching 2,000 degrees. This high-temperature environment is ideal for co-processing, ensuring the complete thermal destruction of organic compounds without generating toxic residues. The physics are in our favour. The infrastructure is not.
Pre-processing is not the support act for co-processing. It is the main event. Get the particle size wrong, get the moisture wrong, get the calorific value wrong and your kiln thermal stability will suffer the consequences.
The Regulatory Push Is Real
The Solid Waste Management (SWM) Rules 2026 mandate that cement plants progressively replace solid fossil fuels with Refuse-Derived Fuel (RDF), starting at a 5 per cent baseline and scaling to 15 per cent within six years. NITI Aayog’s 2026 Roadmap for Cement Sector Decarbonisation targets 20 to 25 per cent Thermal Substitution Rate (TSR) by 2030. Beyond compliance, every tonne of coal replaced by RDF generates measurable carbon reductions which is monetisable under India’s emerging Carbon Credit Trading Scheme (CCTS). TSR is no longer a sustainability metric. It is a financial lever.
Yet our own field assessments across multiple Indian cement plants reveal a sobering reality: the primary barrier to scaling AFR adoption is not waste availability. It is the fragmented and under-engineered pre-processing ecosystem that sits between the waste and the kiln.
Why Indian Waste Is a Different Engineering Problem
Indian municipal solid waste is not the material that imported shredding equipment was designed for. Our waste streams frequently exceed 40 per cent to 50 per cent moisture content, particularly during monsoon cycles, saturated with abrasive inerts including sand, glass, and stone. Plants relying on imported OEM equipment face months of downtime awaiting proprietary spare parts. Machines built for segregated, low-moisture waste fail quickly and disrupt the entire pre-processing operation in Indian conditions.
The two most common failures we observe are what I call the biting teeth problem and the chewing teeth problem. Plants relying solely on a primary shredder reduce bulk waste to large fractions, but the output remains too coarse for stable kiln combustion. Others attempt to use a secondary shredder as a standalone unit without a primary stage to pre-size the feed, leading to catastrophic mechanical failure. When both stages are present but mismatched in throughput capacity, the system becomes a bottleneck. Achieving the 40 to 70 tonnes per hour required for meaningful coal displacement demands a precisely coordinated two-stage process.
Engineering a Made-in-India Answer
At Fornnax, our response to these challenges is grounded in one principle: Indian waste demands Indian engineering. Our systems are built around feedstock homogeneity, the holy grail of kiln stability. Consistent particle size and predictable calorific value are the foundation of stable kiln combustion. Without them, no TSR target is achievable at scale.
Our SR-MAX2500 Dual Shaft Primary Shredder (Hydraulic Drive) processes raw, baled, or loosely mixed MSW, C&I waste, bulky waste, and plastics, reducing them to approximately 150 mm fractions at throughputs of up to 40 tonnes per hour. The R-MAX 3300 Single Shaft Secondary Shredder (Hydraulic Drive), introduced in 2025, takes that primary output and produces RDF fractions in the 30 to 80 mm range at up to 30 tonnes per hour, specifically optimised for consistent kiln feeding. We have also introduced electric drive configurations under the SR-100 HD series, with capacities between 5 and 40 tonnes per hour, already operational at a leading Indian waste-processing facility.
Looking ahead, Fornnax is expanding its portfolio with the upcoming SR-MAX3600 Hydraulic Drive primary shredder at up to 70 tonnes per hour and the R-MAX2100 Hydraulic drive secondary shredder at up to 20 tonnes per hour, designed specifically for the large-scale throughput that higher TSR ambitions require.
The Investment Case Is Now
The 2070 Net-Zero target is not a distant goal for India’s cement sector. It starts today, with decisions being made on the plant floor.
The SWM Rules 2026 are already in effect, requiring cement plants to replace coal with RDF. Carbon credit markets are opening up, and coal prices are not going to get cheaper. Every tonne of coal a cement plant replaces with waste-derived fuel saves money on one side and generates carbon credit revenue on the other. Pre-processing infrastructure is no longer just a compliance requirement. It is a business investment with a measurable return.
The good news is that nothing is missing. The technology works. The waste is available in every Indian city. The government has provided the policy direction. The only thing standing between where the industry is today and where it needs to be is the commitment to build the right infrastructure.
The cement companies that move now will not just meet the regulations. They will be ahead of every competitor that waits.
About The Author
Jignesh Kundaria is the Director and CEO of Fornnax Technology. Over an experience spanning more than two decades in the recycling industry, he has established himself as one of India’s foremost voices on waste-to-fuel technology and alternative fuel infrastructure.
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