Economy & Market

We are actively working on sludge utilisation

Published

10 months ago

May 13, 2025

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Dr Yogendra Kanitkar, VP – Research and Development, Pi Green Innovations, discusses groundbreaking, scalable clean-tech solutions.

As the world races to combat climate change, a simple observation sparked a powerful vision for a pollution-free tomorrow. Dr Yogendra Kanitkar, VP – Research and Development, Pi Green Innovations, talks to Kanika Mathur about how filter-less technology is changing the game – from capturing soot to permanently sequestering CO2 in building materials. Read on to explore how this startup is turning industrial waste into climate solutions.

Can you briefly introduce Pi Green Innovations and its mission for a pollution-free tomorrow?
Pi Green Innovations is a clean tech startup. Our founders are Irfan Pathan, Shantanu Sonaikar, and Rizwan Shaikh. We started with a vision of a pollution-free tomorrow. Our founder, Rizwan Shaikh, observed the dust accumulation on AC filters and realised Delhi’s air pollution was a massive issue. Inspired to create a solution, he began searching for a filterless technology to clean air. That’s how the initial Carbon Cutter machine was conceptualised. The first application was for diesel generators. In 2012–2013, the National Green Tribunal (NGT) ordered diesel generator operators to install Retrofit Emission Control Devices (RECDs) to capture more than 70 per cent of particulate matter. This initially rolled out in Delhi NCR and later became mandatory nationwide.
We invented a filterless technology using electrostatic precipitation (ESP) to capture soot from diesel generators without interfacing with the engine. The soot is collected in a separate tank or vessel that can be cleaned later. This innovation gained traction, and major diesel generator OEMs became our channel partners, certifying and fitting our devices to their generators.
Later, some customers asked if we could also capture gaseous emissions like SOx and NOx. While exploring this, we accidentally discovered that our technology had a greater affinity for capturing CO2. This led to the birth of the Net Zero Machine — a point-source greenhouse gas capture device that converts CO2 into carbonates using accelerated mineral carbonation technology.
To our knowledge, we are the only company in India to operate this technology at such a large scale. While typical lab-scale pilots capture around 1 tonne of CO2 per day, our largest pilot with an Institutional Thermal Power Plant Operator which will be commissioned soon. It will two tonnes of CO2 per day, operational for 21 consecutive days.
Our focus is not just on carbon capture but on carbon utilisation — turning captured CO2 into building materials like bricks, aggregates and road fill. This provides a scalable solution to address industrial emissions while creating valuable byproducts.

How does your Net Zero Machine contribute to carbon capture and green cement production?
To understand our contribution, you first need to understand how cement is produced. Cement production typically involves calcining dolomite to form clinker — the main binding agent in cement. Our ethos is to use industrial waste to capture CO2. We have developed 10 different chemistries with the Net Zero Machine tailored for hard-to-abate sectors like cement, steel, petrochemicals, FMCG and others. For instance, if we are operating at a thermal power plant, we use the fly ash generated there along with other chemicals. When the flue gas passes through the Net Zero Machine, it reacts to form a sludge that self-hardens upon curing. This sludge can be moulded into bricks, road fill, coarse aggregates and other building materials. Importantly, the CO2 captured is permanently sequestered within the solid material — it will not release back unless heated to above 600°C. Unlike other technologies, like amine-based or retisol systems that produce pure CO2 gas, our process embeds CO2 into solid building materials, ensuring long-term storage.
In the cement industry context, let’s say we are working with a steel manufacturer. Normally, blast furnace slag is sold as a cement additive. In our case, we carbonate the industrial waste like slag — through the Net Zero Machine. The carbonation adds CO2 mass into the material, which can then be used as a substitute for clinker or other additives in cement production. For example, if you start with one tonne of blast furnace slag and add 500 kg of CO2 during carbonation, you end up with 1.5 tonnes of carbonated slag. Chemically, the properties remain largely similar.
Thus, instead of disturbing the existing symbiosis between industries like steel and cement, we add value by enhancing the material mass and permanently sequestering carbon — directly contributing to the decarbonisation of the cement industry.

What makes your carbon-negative bricks unique compared to conventional building materials?
They are different in two major aspects. First, if you look at how traditional bricks are made, you take sand, add a binder and then bake the bricks at high temperatures. Each of these steps requires a certain amount of energy, and the biggest energy input is during the baking process, where fossil fuels are burned, emitting CO2.
Now, when you use our bricks, because they are made from industrial waste, there is no CO2 output associated with the raw material itself. You are avoiding emissions by substituting traditional bricks with our product. This is known as an ‘avoidance credit’ or avoided CO2 — you are preventing a certain amount of CO2 emissions by choosing a product with a lower carbon footprint.
The second aspect is the way we manufacture our bricks. We do not bake them. Instead, the bricks are sun-dried and carbonated. The industrial waste, like blast furnace slag or fly ash, is carbonated and self-hardens to form the brick. This means the brick already has captured and sequestered CO2 stored within it.
So, in our product, you have two forms of CO2 benefits: one is captured CO2, and the other is avoided CO2. When you combine these two, that becomes our unique selling proposition compared to normal bricks. That’s why we call them carbon-negative bricks.

How scalable is your Net Zero solution for industries like cement manufacturing?
For the cement industry, scalability is built into the core of our Net Zero solution. Our machine is entirely modular. What we usually propose to clients is: install one unit first, see how it works and then scale up. We have the flexibility to install up to a hundred units in a facility. It is very scalable and modular — you can easily grow based on requirements.
Now, the scaling isn’t purely linear or exponential, but it definitely scales, and there’s a cost curve based on techno-economic analysis where we help clients determine the optimum amount of CO2 they want to capture.

In your view, how critical is CCUS technology for India’s decarbonisation journey, especially in heavy industries?
It is highly critical. If you are exporting to carbon-sensitive markets, you are likely to be hit with a carbon tariff. The Carbon Border Adjustment Mechanism (CBAM) is one such example. Even within India, the Carbon Credit Trading Scheme (CCTS) has been notified, and around 283 entities have been obligated to reduce their CO2 footprints. So, Indian industries should wake up to this reality. If you want to remain competitive in foreign markets, adopting CCUS is non-negotiable.
Specifically for cement manufacturers — and speaking frankly — the margins are razor-thin. Steel manufacturers might still afford a capture cost of $50 per tonne of CO2, but for cement companies that’s much harder. That’s where we come in. Our cost of CO2 capture is significantly lower than conventional market solutions. We can achieve capture costs of less than $25 to $30 per tonne. That’s a game-changer.

What future innovations is Pi Green working on to further advance sustainable construction practices?
There are two broad approaches we are pursuing under Project Net Zero. First, under carbon capture utilisation, we are working on using the sludge generated from industrial waste in very innovative ways to sequester CO2 and form different products out of it. That’s an active vertical.
The second vertical involves evaluating whether our technology can be coupled with Compressed Biogas (CBG) plants. In CBG plants, a major impurity in the biogas is CO2. If we remove that CO2, we can increase the purity of the fuel, turning it into high-quality PNG or CNG. This purified fuel can then be used in internal combustion engines and other applications.
Another interest for us in the near future is to evaluate if NetZero Technology can be coupled with coal gasification to produce blue hydrogen.
Besides that, we are actively working on sludge utilisation — finding multiple pathways to make valuable products from the byproducts of the Net Zero process.
Those are the three major innovations we are actively working on.

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Economy & Market

Smart Pumping for Rock Blasting

Published

5 days ago

March 2, 2026

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SEEPEX introduces BN pumps with Smart Joint Access (SJA) to improve efficiency, reliability, and inspection speed in demanding rock blasting operations.
Designed for abrasive and chemical media, the solution supports precise dosing, reduced downtime, and enhanced operational safety.

SEEPEX has introduced BN pumps with Smart Joint Access (SJA), engineered for the reliable and precise transfer of abrasive, corrosive, and chemical media in mining and construction. Designed for rock blasting, the pump features a large inspection opening for quick joint checks, a compact footprint for mobile or skid-mounted installations, and flexible drive and material options for consistent performance and uptime.

“Operators can inspect joints quickly and rely on precise pumping of shear-sensitive and abrasive emulsions,” said Magalie Levray, Global Business Development Manager Mining at SEEPEX. “This is particularly critical in rock blasting, where every borehole counts for productivity.” Industry Context

Rock blasting is essential for extracting hard rock and shaping safe excavation profiles in mining and construction. Accurate and consistent loading of explosive emulsions ensures controlled fragmentation, protects personnel, and maximizes productivity. Even minor deviations in pumping can cause delays or reduce product quality. BN pumps with SJA support routine maintenance and pre-operation checks by allowing fast verification of joint integrity, enabling more efficient operations.

Always Inspection Ready

Smart Joint Access is designed for inspection-friendly operations. The large inspection opening in the suction housing provides direct access to both joints, enabling rapid pre-operation checks while maintaining high operational reliability. Technicians can assess joint condition quickly, supporting continuous, reliable operation.

Key Features

Compact Footprint: Fits truck-mounted mobile units, skid-mounted systems, and factory installations.
Flexible Drive Options: Compact hydraulic drive or electric drive configurations.
Hydraulic Efficiency: Low-displacement design reduces oil requirements and supports low total cost of ownership.
Equal Wall Stator Design: Ensures high-pressure performance in a compact footprint.
Material Flexibility: Stainless steel or steel housings, chrome-plated rotors, and stators in NBR, EPDM, or FKM.

Operators benefit from shorter inspection cycles, reliable dosing, seamless integration, and fast delivery through framework agreements, helping to maintain uptime in critical rock blasting processes.

Applications – Optimized for Rock Blasting

BN pumps with SJA are designed for mining, tunneling, quarrying, civil works, dam construction, and other sectors requiring precise handling of abrasive or chemical media. They provide robust performance while enabling fast, reliable inspection and maintenance.With SJA, operators can quickly access both joints without disassembly, ensuring emulsions are transferred accurately and consistently. This reduces downtime, preserves product integrity, and supports uniform dosing across multiple bore holes.

With the Smart Joint Access inspection opening, operators can quickly access and assess the condition of both joints without disassembly, enabling immediate verification of pump readiness prior to blast hole loading. This allows operators to confirm that emulsions are transferred accurately and consistently, protecting personnel, minimizing product degradation, and maintaining uniform dosing across multiple bore holes.

The combination of equal wall stator design, compact integration, flexible drives, and progressive cavity pump technology ensures continuous, reliable operation even in space-limited, high-pressure environments.

From Inspection to Operation

A leading explosives provider implemented BN pumps with SJA in open pit and underground operations. By replacing legacy pumps, inspection cycles were significantly shortened, allowing crews to complete pre-operation checks and return mobile units to productive work faster. Direct joint access through SJA enabled immediate verification, consistent emulsion dosing, and reduced downtime caused by joint-related deviations.

“The inspection opening gives immediate confidence that each joint is secure before proceeding to bore holes,” said a site technician. “It allows us to act quickly, keeping blasting schedules on track.”

Framework agreements ensured rapid pump supply and minimal downtime, supporting multi-site operations across continents

Concrete

Digital process control is transforming grinding

Published

2 weeks ago

February 20, 2026

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Satish Maheshwari, Chief Manufacturing Officer, Shree Cement, delves into how digital intelligence is transforming cement grinding into a predictive, stable, and energy-efficient operation.

Grinding sits at the heart of cement manufacturing, accounting for the largest share of electrical energy consumption. In this interview, Satish Maheshwari, Chief Manufacturing Officer, Shree Cement, explains how advanced grinding technologies, data-driven optimisation and process intelligence are transforming mill performance, reducing power consumption and supporting the industry’s decarbonisation goals.

How has the grinding process evolved in Indian cement plants to meet rising efficiency and sustainability expectations?
Over the past decade, Indian cement plants have seen a clear evolution in grinding technology, moving from conventional open-circuit ball mills to high-efficiency closed-circuit systems, Roller Press–Ball Mill combinations and Vertical Roller Mills (VRMs). This shift has been supported by advances in separator design, improved wear-resistant materials, and the growing use of digital process automation. As a result, grinding units today operate as highly controlled manufacturing systems where real-time data, process intelligence and efficient separation work together to deliver stable and predictable performance.
From a sustainability perspective, these developments directly reduce specific power consumption, improve equipment reliability and lower the carbon footprint per tonne of cement produced.

How critical is grinding optimisation in reducing specific power consumption across ball mills and VRMs?
Grinding is the largest consumer of electrical energy in a cement plant, which makes optimisation one of the most effective levers for improving energy efficiency. In ball mill systems, optimisation through correct media selection, charge design, diaphragm configuration, ventilation management and separator tuning can typically deliver power savings of 5 per cent to 8 per cent. In VRMs, fine-tuning airflow balance, grinding pressure, nozzle ring settings, and circulating load can unlock energy reductions in the range of 8 per cent to 12 per cent. Across both systems, sustained operation under stable conditions is critical. Consistency in mill loading and operating parameters improves quality control, reduces wear, and enables long-term energy efficiency, making stability a key operational KPI.

What challenges arise in maintaining consistent cement quality when using alternative raw materials and blended compositions?
The increased use of alternative raw materials and supplementary cementitious materials (SCM) introduces variability in chemistry, moisture, hardness, and loss on ignition. This variability makes it more challenging to maintain consistent fineness, particle size distribution, throughput and downstream performance parameters such as setting time, strength development and workability.
As clinker substitution levels rise, grinding precision becomes increasingly important. Even small improvements in consistency enable higher SCM utilisation without compromising cement performance.
Addressing these challenges requires stronger feed homogenisation, real-time quality monitoring and dynamic adjustment of grinding parameters so that output quality remains stable despite changing input characteristics.

How is digital process control changing the way grinding performance is optimised?
Digital process control is transforming grinding from an operator-dependent activity into a predictive, model-driven operation. Technologies such as online particle size and residue analysers, AI-based optimisation platforms, digital twins for VRMs and Roller Press systems, and advanced process control solutions are redefining how performance is managed.
At the same time, workforce roles are evolving. Operators are increasingly focused on interpreting data trends through digital dashboards and responding proactively rather than relying on manual interventions. Together, these tools improve mill stability, enable faster response to disturbances, maintain consistent fineness, and reduce specific energy consumption while minimising manual effort.

How do you see grinding technologies supporting the industry’s low-clinker and decarbonisation goals?
Modern grinding technologies are central to the industry’s decarbonisation efforts. They enable higher incorporation of SCMs such as fly ash, slag, and limestone, improve particle fineness and reactivity, and reduce overall power consumption. Efficient grinding makes it possible to maintain consistent cement quality at lower clinker factors. Every improvement in energy intensity and particle engineering directly contributes to lower CO2 emissions.
As India moves toward low-carbon construction, precision grinding will remain a foundational capability for delivering sustainable, high-performance cement aligned with national and global climate objectives.

How much potential does grinding optimisation hold for immediate energy
and cost savings?
The potential for near-term savings is substantial. Without major capital investment, most plants can achieve 5 per cent to 15 per cent power reduction through measures such as improving separator efficiency, optimising ventilation, refining media grading, and fine-tuning operating parameters.
With continued capacity expansion across India, advanced optimisation tools will help ensure that productivity gains are not matched by proportional increases in energy demand. Given current power costs, this translates into direct and measurable financial benefits, making grinding optimisation one of the fastest-payback operational initiatives available to cement manufacturers today.

Concrete

Refractory demands in our kiln have changed

Published

2 weeks ago

February 20, 2026

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Radha Singh, Senior Manager (P&Q), Shree Digvijay Cement, points out why performance, predictability and life-cycle value now matter more than routine replacement in cement kilns.

As Indian cement plants push for higher throughput, increased alternative fuel usage and tighter shutdown cycles, refractory performance in kilns and pyro-processing systems is under growing pressure. In this interview, Radha Singh, Senior Manager (P&Q), Shree Digvijay Cement, shares how refractory demands have evolved on the ground and how smarter digital monitoring is improving kiln stability, uptime and clinker quality.

How have refractory demands changed in your kiln and pyro-processing line over the last five years?
Over the last five years, refractory demands in our kiln and pyro line have changed. Earlier, the focus was mostly on standard grades and routine shutdown-based replacement. But now, because of higher production loads, more alternative fuels and raw materials (AFR) usage and greater temperature variation, the expectation from refractory has increased.
In our own case, the current kiln refractory has already completed around 1.5 years, which itself shows how much more we now rely on materials that can handle thermal shock, alkali attack and coating fluctuations. We have moved towards more stable, high-performance linings so that we don’t have to enter the kiln frequently for repairs.
Overall, the shift has been from just ‘installation and run’ to selecting refractories that give longer life, better coating behaviour and more predictable performance under tougher operating conditions.

What are the biggest refractory challenges in the preheater, calciner and cooler zones?
• Preheater: Coating instability, chloride/sulphur cycles and brick erosion.
• Calciner: AFR firing, thermal shock and alkali infiltration.
• Cooler: Severe abrasion, red-river formation and mechanical stress on linings.
Overall, the biggest challenge is maintaining lining stability under highly variable operating conditions.

How do you evaluate and select refractory partners for long-term performance?
In real plant conditions, we don’t select a refractory partner just by looking at price. First, we see their past performance in similar kilns and whether their material has actually survived our operating conditions. We also check how strong their technical support is during shutdowns, because installation quality matters as much as the material itself.
Another key point is how quickly they respond during breakdowns or hot spots. A good partner should be available on short notice. We also look at their failure analysis capability, whether they can explain why a lining failed and suggest improvements.
On top of this, we review the life they delivered in the last few campaigns, their supply reliability and their willingness to offer plant-specific custom solutions instead of generic grades. Only a partner who supports us throughout the life cycle, which includes selection, installation, monitoring and post-failure analysis, fits our long-term requirement.

Can you share a recent example where better refractory selection improved uptime or clinker quality?
Recently, we upgraded to a high-abrasion basic brick at the kiln outlet. Earlier we had frequent chipping and coating loss. With the new lining, thermal stability improved and the coating became much more stable. As a result, our shutdown interval increased and clinker quality remained more consistent. It had a direct impact on our uptime.

How is increased AFR use affecting refractory behaviour?
Increased AFR use is definitely putting more stress on the refractory. The biggest issue we see daily is the rise in chlorine, alkalis and volatiles, which directly attack the lining, especially in the calciner and kiln inlet. AFR firing is also not as stable as conventional fuel, so we face frequent temperature fluctuations, which cause more thermal shock and small cracks in the lining.
Another real problem is coating instability. Some days the coating builds too fast, other days it suddenly drops, and both conditions impact refractory life. We also notice more dust circulation and buildup inside the calciner whenever the AFR mix changes, which again increases erosion.
Because of these practical issues, we have started relying more on alkali-resistant, low-porosity and better thermal shock–resistant materials to handle the additional stress coming from AFR.

What role does digital monitoring or thermal profiling play in your refractory strategy?
Digital tools like kiln shell scanners, IR imaging and thermal profiling help us detect weakening areas much earlier. This reduces unplanned shutdowns, helps identify hotspots accurately and allows us to replace only the critical sections. Overall, our maintenance has shifted from reactive to predictive, improving lining life significantly.

How do you balance cost, durability and installation speed during refractory shutdowns?
We focus on three points:
• Material quality that suits our thermal profile and chemistry.
• Installation speed, in fast turnarounds, we prefer monolithic.
• Life-cycle cost—the cheapest material is not the most economical. We look at durability, future downtime and total cost of ownership.
This balance ensures reliable performance without unnecessary expenditure.

What refractory or pyro-processing innovations could transform Indian cement operations?
Some promising developments include:
• High-performance, low-porosity and nano-bonded refractories
• Precast modular linings to drastically reduce shutdown time
• AI-driven kiln thermal analytics
• Advanced coating management solutions
• More AFR-compatible refractory mixes

These innovations can significantly improve kiln stability, efficiency and maintenance planning across the industry.