Economy & Market

Green sustainability in cement

Published

11 years ago

April 30, 2015

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Aryabrat Ghosh observes that 2020 will be a year of green sustainability for cement industry where the ground work has already started.

Cement industry is one of the two primary industrial producers of carbon dioxide (CO2), creating up to 5 per cent of worldwide man-made emissions of this gas, of which 50 per cent is from the chemical process and 40 per cent from burning fuel. The CO2 produced for the manufacture of one tonne of structural concrete (using ~14 per cent cement) is estimated at 410 kg/cu m (~180 kg/tonne at a density of 2.3 g/cu cm) (reduced to 290 kg/cu m with 30 per cent fly ash replacement of cement). The CO2 emission from concrete production is directly proportional to the cement content used in the concrete mix; 900 kg of CO2 are emitted for the fabrication of every tonne of cement. Cement manufacturer contributes greenhouse gases both directly through the production of CO2 when calcium carbonate is thermally decomposed, producing lime and CO2 and also through the use of energy, particularly from the combustion of fossil fuels.

One reason why the carbon emissions are so high is because cement has to be heated to very high temperatures in order to form clinker. A major culprit of this is alite (Ca3SiO5), a mineral in concrete that cures within hours of pouring and is therefore responsible for much of its initial strength. However, alite also has to be heated to 1,500?C in the clinker-forming process.

Some research suggests that alite can be replaced by a different mineral, such as belite (Ca2SiO4). Belite is also a mineral already used in concrete. It has a roasting temperature of 1,200?C, which is significantly lower than that of alite. Furthermore, belite is actually stronger once concrete cures. However, belite takes on the order of days or months to set completely, which leaves concrete weak for an unacceptably long period of time.

Current research is focusing on finding possible impurity additives, like magnesium, that might speed up the curing process. It is also worthwhile to consider that belite takes more energy to grind, which may make its full life impact similar to or even higher than alite.

Another approach has been the partial replacement of conventional clinker with such alternatives as fly ash, bottom ash, and slag, all of which are by-products of other industries that would otherwise end up in landfills. Fly ash and bottom ash come from thermoelectric power plants, while slag is a waste from blast furnaces in the ironworks industry. These materials are slowly gaining popularity as additives, especially since they can potentially increase strength, decrease density, and prolong durability of concrete.

The main obstacle to wider implementation of fly ash and slag may be largely due to the risk of construction with new technology that has not been exposed to long field testing. Until a carbon tax is implemented, companies are unwilling to take the chance with new concrete mix recipes even if this reduces carbon emissions.

In India, typical usage of fly ash in PPC type of cement may range from 23 per cent to 26 per cent (average) whereas Bureau of Indian Standard (BIS) has allowed the limit till 35 per cent (in coming years the limit may exceed to 40 per cent), so there is a huge scope to increase fly ash. Chryso in India brings the solution (performance enhancers) to help reduce the issues given above like solutions to increase fly ash/slag content in PPC and PSC type of cement or to save energy by solutions like grinding aid for all type of cements (PPC/PSC/OPC) and also raw meal. With the help of its R&D centre in Turbhe, Navi Mumbai, the discussions has already started with many big cement groups to come up with solutions for the future where we are talking about complex type of cement product (addition of fly ash/slag/limestone in one type of cement) and increase of fly ash (to 40 per cent).

To summarise, one can say that 2020 will also be a year of green sustainability for cement industry where the ground work has already started.

Economy & Market

TSR Will Define Which Cement Companies Win India’s Net-Zero Race

Published

3 days ago

April 27, 2026

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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.

Concrete

WCA Welcomes SiloConnect as associate corporate member

Published

2 weeks ago

April 13, 2026

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The World Cement Association (WCA) has announced SiloConnect as its newest associate corporate member, expanding its network of technology providers supporting digitalisation in the cement industry. SiloConnect offers smart sensor technology that provides real-time visibility of cement inventory levels at customer silos, enabling producers to monitor stock remotely and plan deliveries more efficiently. The solution helps companies move from reactive to proactive logistics, improving delivery planning, operational efficiency and safety by reducing manual inspections. The technology is already used by major cement producers such as Holcim, Cemex and Heidelberg Materials and is deployed across more than 30 countries worldwide.

Concrete

TotalEnergies and Holcim Launch Floating Solar Plant in Belgium

Published

2 weeks ago

April 13, 2026

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TotalEnergies and Holcim have commissioned a floating solar power plant in Obourg, Belgium, built on a rehabilitated former chalk quarry that has been converted into a lake. The project has a generation capacity of 31 MW and produces around 30 GWh of renewable electricity annually, which will be used to power Holcim’s nearby industrial operations. The project is currently the largest floating solar installation in Europe dedicated entirely to industrial self-consumption. To ensure minimal impact on the surrounding landscape, more than 700 metres of horizontal directional drilling were used to connect the solar installation to the electrical substation. The project reflects ongoing collaboration between the two companies to support industrial decarbonisation through renewable energy solutions and innovative infrastructure development.