Concrete

Optimising Heat Utilisation

Published

4 years ago

April 1, 2022

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With Waste Heat Recovery as a viable alternative for the power needs of cement plants, Triveni Turbines presents case studies to support their findings on the role of thermal renewable fuels in aiding the cement sector inch closer to its goal of a sustainable future.

The cement industry is an energy-intensive industry. On an average, the energy cost is around 40 per cent of the cost of production for cement manufacturing. The heat generated in cement processes is generally lost up to 30 to 40 per cent.
Cement plants in India have Captive Power Plants (CPP), which are fired using fossil fuel (coal). These are in operation for several decades. Nowadays, the CPPs installed in cement plants use heat through Waste Heat Recovery (WHR) to generate power. Typically 20 to 30 per cent of the power requirement for cement plants can be fulfilled using waste heat for power generation.
Globally, WHR based plants installed in the cement industry are based on three processes, namely

Steam Rankine Cycle System (SRC)
Organic Rankine Cycle System (ORC)
Kalina Based System

The function of the WHR is to recover the heat from the hot stream using Heat Recovery Steam Generators (HRSG) or Waste Heat Recovery Boiler (WHRB) to generate superheated steam. It can be used in the process (for co-generation) or to drive a steam turbine (combined cycle).
The WHR based power plants installed in cement processing plants use the heat generated through rotary kiln preheater (PH) and after quenching cooler (AQC) exhaust hot gases for power generation.
In India, the customer prefers SRC for WHR power generation in Cement Plants. Technically, in SRC, the exhaust gases from the rotary kiln pass through PH and go to the PH boiler. Similarly, mid-tapping from AQC gives hot gases to the AQC boiler. One cement kiln line requires 2 PH boilers and 1 AQC boiler. Based on the heat source, these boilers generate low-pressure steam of 12 ata to 18 ata at a temperature of 350 to 450 degree Celsius. and Low Pressure (LP)steam 2 ata to 3 ata pressure and temperature of 175 to 195 degree Celsius.
WHR-based power plants also exist in the sectors like sponge iron, steel and chemicals, which came into existence from the year 2000 onwards in the Indian market. Initially in India, the major cement manufacturers installed cement WHR plants made in China while over the last decade or so, Indian boiler and Turbine OEMs offered products indigenously designed and manufactured catering to the market dynamics, demand requirements and providing sustained long-term aftermarket services.

**Steam turbines for a Waste Heat Recovery based power plants in an overseas location.**

Cement WHR
Triveni Turbines is associated with cement WHR for many years now and has executed numerous prestigious projects with leading cement manufacturers in India and abroad. The requirement for cement WHR depends on the cement kiln capacity, heat utilisation, and plant efficiency.
Triveni is currently in the process of installing many cement WHR projects and is also working on multiple projects that are either in the enquiry or in the order finalisation stage.
Triveni has developed efficient injection condensing turbines that use medium pressure steam as turbine inlet and low pressure as injection steam. With the addition of 7th generation turbine blades developed by Triveni, power generation output is more for input steam parameters or gas parameters.

Salient features of Triveni’s steam turbines in the cement industry are as follows:

Integral Lube Oil tank: Triveni offers an Integral Lube Oil tank for Power House Layout and civil cost optimisations of TG House. The benefits include a reduction in the civil cost of the project.
Mechanical Run Test (MRT): Live steam mechanical run test at Triveni’s manufacturing facility for the steam turbines. The Turbine is tested with live steam from boilers at Bengaluru works with job-mounted turbo supervisory systems, Woodward governor, and gearbox.
In-house Manufacturing: Turbine components like blades, rotors, and casing are manufactured and assembled at Triveni’s facility.
Vacuum Tunnel: High-speed balancing of turbine rotor on ‘Schenk’ Vacuum Tunnel
Gear Box (Triveni Power Transmission) assembly is done along with the Turbine on the same base plate and converts into a single product. A separate foundation of the gearbox is not required.
Inlet Valve: Triveni supplies a customised inlet governing valve is designed in-house to overcome the varied load fluctuations in the cement industry
Injection Control Valve: Triveni supplies a specially designed globe control valve to maintain the minimum differential pressure to avoid the energy loss which results in the indirect losses in the final output.

Best practices on steam turbine design solution
Large cement companies are primarily considering WHR power plants for their Greenfield projects. Dependency on the Chinese turbines has now declined in the Indian market as the Indian OEM’s adapted to injection condensing turbines technology with a dominant leadership. Triveni has a firm reference of injection condensing turbines supplied to cement WHR plants across India.
Specific design consideration is vital in the injection and admission zone. The rotor designed by Triveni has the higher stability to offset the excitation due to fluctuating injection steam loads. To meet customer requirements for various mid-pressure and low-pressure steam combinations, an injection condensing turbine was developed by Triveni and is successfully working in the Indian Cement Industry. Design and engineering teams carried out Computational Fluid Dynamic (CFD) analysis and creep-fatigue analysis to address this issue. This design philosophy is a value-addition for Triveni for its robust and efficient cement
WHR solution.

Environmental concerns and the solutions offered
According to industry sources, cement manufacturing accounts for an estimated 4 to 8 per cent of the world’s carbon dioxide (CO2) emission, making it a significant contributor to global warming. Increasing the energy efficiency of cement plants by replacing fossil fuels with thermal renewable fuels (such as waste heat) and capturing and storing the CO2 to contain greenhouse gas (GHG) emissions are some of the solutions common to the cement industry and other industrial sectors.

WHR power potential
There is a vast potential for power generation from waste heat across the world. The installation of cement WHR based power plants in China is over 80 per cent, much ahead of India. Similarly, Europe, the USA, and Latin America plan to implement WHR in their cement plants. It is observed that waste heat recovery-based power plants are emerging as an excellent value addition to the existing captive power plants. Other than reducing energy costs significantly, it can also be a reliable source of power.

Case studies of Triveni
a. Waste Heat Recovery based Power plant in Madhya Pradesh, India
Driven by Triveni 1*22.5 MWe Injection Condensing steam turbines with an inlet steam parameter of 12 Bar and 425 degree Celsius with 0.2 Bar Exhaust

**Specific design consideration is vital in the injection and admission zone.**

Customer challenge
The steam flow in this project was from multiple sources (i.e., multiple boilers). Steam generation depends on the waste heat generated from hot gas temperature from the preheating process and AQC process. There is a variation in the steam inlet at Medium Pressure (MP) and Low Pressure (LP) side and load variation in load or power output.

Solution
The steam turbine we proposed is an Injection condensing turbine that receives MP steam as an inlet and LP steam as an injection in the middle steam path. The steam collected was from 4 No’s of Preheater (PH) boilers and 2 No’s of After Quenching Cooler (AQC) Boilers from the two cement kilns of 7,000 TPD and 8,000 TPD capacity.
The steam turbine generator (STG) is suitable for an air-cooled condenser with a new generation blade design and reaction stages. Despite various challenges, the commissioning of the Turbine was executed with quick delivery of eight months, which set a benchmark for Triveni in the cement industry.

Benefits
The company does not have a captive power plant installed, and this WHR plant has offered many benefits. The waste gas generated at around
400 degree Celsius is cooled to 130 degree Celsius, thus safeguarding the environment and simultaneously utilising the waste heat to generate almost free power.
b. Waste Heat Recovery based Power plant installed overseas
Driven by Triveni 1*30 MWe Bleed condensing steam turbines with an inlet steam pressure of
65 Bar and 505 degree Celsius with 0.1 Bar
Exhaust pressure

Customer challenge
The customer proposed installing a power plant and expanding the company’s manufacturing capacity and was on the lookout for a steam turbine solution provider. The customer wanted to generate the necessary power by banking on their captive power capacities and to ensure a steady supply for critical processes.

Solution
Triveni offered the best solution to meet the plant efficiency by utilising the waste heat recovered from the existing blast furnace for power generation.

Benefits The company entrusted Triveni’s expertise in manufacturing robust and highly reliable products. It awarded us with the supply contract of a steam turbine that benefits from improving the plant’s energy efficiency, reducing the energy cost, and transmitting surplus electricity to the grid.
To complement the above new product portfolio, Triveni’s refurbishment arm Triveni REFURB steps up to provide an aftermarket solution for the complete range of rotating equipment across the globe. From steam turbines, compressors to the gas turbine range, we have adapted ourselves to ensure that customers find a one stop solution.
Over a period of time, the existing turbines degrade thereby reducing the efficiency of the turbines by consuming more steam. The Triveni REFURB team provides solutions to enhance the efficiency of turbines of ‘Any make, Any age’ by only replacing the critical components of the turbine i.e., rotor, guide blade carriers and bearings, which ensures the efficiency is restored and thereby reducing the carbon footprint.
Triveni REFURB converts the existing turbine into injection mode turbine. The turbines are then re-engineered to allow additional steam to be injected into the turbine and improve the efficiency of the plant.
a. Conversion of Bleed Condensing Turbine to Injection Condensing
A Chinese Turbine 1*25MWe Bleed Condensing Turbine with 84 Bar 515 degree Celsius inlet conditions and 0.176 Bar Exhaust pressure

Customer challenge
A major cement Industry customer wanted to convert their existing Chinese make turbine from a 3 bleed condensing to injection condensing turbine. The pressure at the inlet was reduced to 13 Bar 425 degree Celsius as against 84 bar 515 degree Celsius. The injection parameters are 2.25 Bar 185 degree Celsius.

Solution
Due to the steep drop in inlet pressure the volumetric expansion was almost three times the original condition. We had proposed to modify the Inlet valve of the turbine and the first stage nozzles to accommodate this expansion. Two bleed ports were closed and the injection would be taken from the third bleed port. Complete re-engineering of the turbine was undertaken to adopt the upgraded steam flow path.

Benefits By keeping the existing casing and civil foundation, customers benefited by lower expenditure and improved efficiency. This would enable the customer to get a faster Return on Investment (within 2 years) and enhanced life of the turbine.

Author: Arun Mote, Executive Director, Triveni Turbine Limited

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The primary high-power applications are fans and mills

Published

2 days ago

October 10, 2025

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Alex Nazareth, Whole-time Director and CEO, Innomotics India, explains how plants can achieve both cost competitiveness and sustainability by lowering emissions, reducing downtime and planning for significant power savings.

As one of the most energy-intensive industries, cement manufacturing faces growing pressure to optimise power consumption, reduce emissions and improve operational reliability. Technology providers like Innomotics India are enabling this transformation by combining advanced motors, AI-driven digital solutions and intelligent monitoring systems that enhance process stability and reduce energy costs. From severe duty motors built for extreme kiln environments to DigiMine AI solutions that optimise pyro and mill operations, Alex Nazareth, Whole-time Director and CEO, Innomotics India, explains how the company is helping cement plants achieve measurable energy savings while moving closer to their sustainability goals.

How does your Energy Performance Contracting model typically reduce power consumption in cement plants—e.g., MWh saved?
Our artificial intelligence-based DigiMine AI Pyro and Mill solutions developed specifically for the cement industry, supports our customers in improving their process stability, productivity and process efficiency. In Pyro, this is achieved by optimising fuel consumption (Coal / AFR), reducing Specific Heat Consumption and reduction in emissions (CO2, SOx and NOx) through continuous monitoring of thermodynamics in pyro and recommending set-points of crucial parameters in advance for maintaining stable operations.
Within the mill, this is achieved by improving throughput, reduce energy / power consumption and maintaining stable operations on a continuous basis. Our ROI-based value proposition captures the project KPIs like reduction of coal usage, increase of AFR, reduction of specific heat consumption (Kcal / Kg), reduction of specific power consumption (KWH / tonne), reduction of emissions, etc., by a specific percentage. This gives clarity to our customers to understand the investment vis-à-vis savings and estimate the recovery time of their investment, which typically is achieved within one year of DigiMine AI Pyro and Mill solutions implementation.

What role do digitalisation and motor monitoring play in overall plant energy optimisation?
Motors are being used extensively in cement production, and their monitoring play crucial role in ensuring continuous operation of applications. The monitoring system can automatically generate alerts for any anomaly / abnormalities in motor parameters, which allows plant team to take corrective actions and avoid any major equipment damage and breakdown. The alerts help maintenance team to plan maintenance schedule and related activity efficiently. Centralised and organised data gives overview to the engineers for day-to-day activities. Cement is amongst the top energy intensive industries in comparison to other industries. Hence, it becomes critically important to optimise efficiency, productivity and up-time of plant equipment. Motor monitoring and digitalisation plays a vital role in it. Monitoring and control of multiple applications and areas
within the plant or multiple plants becomes possible with digitalisation.
Digitalisation adds a layer on top of OT systems, bringing machine and process data onto a single interface. This solves the challenges such as system silo, different communications protocol, databases and most importantly, creates a common definition and measurement to plant KPIs. Relevant stakeholders, such as engineers, head of departments and plant heads, can see accurate information, analyse it and make better decisions with appropriate timing. In doing so, plant teams can take proactive actions before machine breakdown, enable better coordination during maintenance activities while improving operational efficiency and productivity.
Further using latest technologies like Artificial Intelligence can even assist operators in running their plant with minimal requirement of human intervention, which allows operators to utilise their time in focusing on more critical topics like analysing data to identify further improvements in operation.

Which of your high-efficiency IEC low-voltage motors deliver the best energy savings for cement mills or fans?
Innomotics India offers a range of IEC-compliant low-voltage motors engineered to deliver superior performance and energy savings, particularly for applications such as cement mills, large fans, and blowers. Innomotics has the complete range of IE4 motors from 0.37kW to 1000kW to meet the demands of cement industry. The IE5 range is also available for specific requirements.

Can safe area motors operate safely and efficiently in cement kiln environments?
Yes, safe area motors are designed to operate reliably in these environments without the risk of overheating. These motors have ingress protection that prevents dust, moisture ingress and can withstand mechanical stress. These motors are available in IE3 / IE4 efficiency classes thereby ensuring lower energy consumption during continuous operation. These motors comply with relevant Indian as well as international standards.

How do your SD Severe Duty motors contribute to lower emissions and lower cost in heavy duty cement applications?
Severe duty motors enhances energy efficiency and durability in demanding cement applications, directly contributing to lower emissions and operational costs. With high-efficiency ratings (such as IE3 or better), they reduce power consumption, minimising CO2 output from energy use. Their robust design handles extreme heat, dust and vibration—common in cement environments—ensuring reliable performance and fewer energy losses.
These motors also lower the total cost of ownership by reducing downtime, maintenance and replacement frequency. Their extended service life and minimal performance degradation help cement plants meet sustainability targets, comply with emissions regulations and improve overall energy management—all while keeping production consistent and cost-effective.

What pump, fan or compressor drive upgrades have shown approximately 60 per cent energy savings in industrial settings and can be replicated in cement plants?
In the cement industry, the primary high-power applications are fans and mills. Among these, fans have the greatest potential for energy savings. Examples, the pre-heater fan, bag house fan, and cooler fans. When there are variations in airflow or the need to maintain a constant pressure in a process, using a variable speed drive (VSD) system is a more effective option for starting and controlling these fans. This adaptive approach can lead to significant energy savings. For instance, vanes and dampers can remain open while the variable frequency drive and motor system manage airflow regulation efficiently.

Concrete

We conduct regular internal energy audits

Published

2 days ago

October 10, 2025

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Shaping the future of low-carbon cement production involves integrating renewables, digitalisation and innovative technologies. Uma Suryam, SVP and Head Manufacturing – Northern Region, Nuvoco Vistas, gives us a detailed account of how.

In an industry where energy consumption can account for a significant portion of operating costs, cement manufacturers are under increasing pressure to adopt sustainable practices without compromising efficiency. Nuvoco Vistas has taken a decisive step in this direction, leveraging digitalisation, renewable energy and innovative technologies to drive energy efficiency across its operations. In this exclusive conversation, Uma Suryam, SVP and Head Manufacturing – Northern Region, Nuvoco Vistas, shares its approach to energy management, challenges of modernising brownfield plants and its long-term roadmap to align efficiency with India’s net-zero vision.

How has your company improved energy efficiency over the past five years?
Over the past five years, we have prioritised energy conservation by enhancing operational efficiency and scaling up renewable energy adoption. Through strategic fuel mix optimisation, deployment of cleaner technologies, and greater integration of renewables, we have steadily reduced our environmental footprint while meeting energy needs sustainably.
Technological upgrades across our plants have further strengthened efficiency. These include advanced process control systems, enhanced trend analysis, grinding media optimisation and the integration of solar-powered utilities. Importantly, grid integration at our key plants has delivered significant cost savings and streamlined energy management.
A notable milestone has been the expansion of our solar power capacity and Waste Heat Recovery Systems (WHRS). Our solar power capacity has grown from 1.5 MW in FY 2021–22 to 5.5 MW, while our WHRS capacity has increased from 44.7 MW to 49 MW, underscoring our commitment to sustainable energy solutions.

What technologies or practices have shown the highest energy-saving potential in cement production?
One of our most significant achievements in advancing energy efficiency has been the successful commissioning of a 132 KV Grid Integration Project, which unified three of our major manufacturing units under a single power network. This milestone, enabled by a dedicated transmission line and a state-of-the-art Line-In Line-Out (LILO) substation, has transformed our energy management and operational capabilities.
With this integration, we have substantially reduced our contract demand, eliminated power disruptions, and enhanced operational continuity. Supported by an optical fibre network for real-time communication and automation, this project stands as a testament to our innovation-led manufacturing excellence and underscores Nuvoco’s vision of building a safer, smarter, and sustainable world.

What role does digitalisation play in achieving energy efficiency in your operations?
Digitalisation plays a transformative role in driving energy efficiency across our operations. At Nuvoco, we are leveraging cutting-edge technologies and advanced digital tools to enhance productivity, optimise energy consumption and strengthen our commitment to sustainability and employee safety.
We are developing AI-enabled dashboards to optimise WHRS and kiln operations, ensuring maximum efficiency. Additionally, our advanced AI models evaluate multiple operational parameters — including fuel pricing, moisture content and energy output — to identify the most cost-effective fuel combinations in real time. These initiatives are enabling data-driven decision-making, improving operational excellence and reducing our environmental footprint.

What is your long-term strategy for aligning energy efficiency with decarbonisation goals?
As part of India’s climate action agenda, the cement sector has laid out a clear decarbonisation roadmap to achieve net-zero CO2 emissions by 2070. At Nuvoco, we view this as both a responsibility and an opportunity to redefine the future of sustainable construction. Our long-term strategy focuses on aligning energy efficiency with decarbonisation goals by embracing innovative technologies, alternative raw materials and renewable energy solutions.
We are making strategic investments to scale up solar power installations and enhance our renewable energy mix significantly by 2028. These initiatives are a key part of our broader vision to reduce Scope 2 emissions and strengthen our contribution to India’s net-zero journey, while continuing to deliver innovative and sustainable solutions to our customers.

How do you measure and benchmark energy performance across different plants?
We adopt a comprehensive approach to measure and benchmark energy performance across our plants. Key metrics include Specific Heat Consumption (kCal/kg of clinker) and Specific Power Consumption (kWh/tonne of cement), which are continuously tracked against Best Available Technology (BAT) benchmarks, industry peers and global standards such as the WBCSD-CSI and CII benchmarks.
To ensure consistency and drive improvements, we conduct regular internal energy audits, leverage real-time dashboards and implement robust KPI tracking systems. These tools enable us to compare performance across plants effectively, identify optimisation opportunities and set actionable targets for energy efficiency and sustainability.

What are the key challenges in adopting energy-efficient equipment in brownfield cement plants?
Adopting energy-efficient technologies in brownfield cement plants presents a unique set of challenges due to the constraints of working within existing infrastructure. Firstly, the high capital expenditure and relatively long payback periods often require careful evaluation before investments are made. Additionally, integrating new technologies with legacy equipment can be complex, requiring significant customisation to ensure seamless compatibility and performance.
Another major challenge is minimising production disruptions during installation. Since brownfield plants are already operational, upgrades must be planned meticulously to avoid affecting output. In many cases, space constraints in older facilities add to the difficulty of accommodating advanced equipment without compromising existing layouts.
At Nuvoco, we address these challenges through a phased implementation approach, detailed project planning and by fostering a culture of innovation and collaboration across our plants. This helps us balance operational continuity with our commitment to driving energy efficiency and sustainability.

Concrete

Enlight Metals Supplies 3,200 Tonne of Steel for Navi Mumbai Airport

The airport is set to become Asia’s largest air connectivity hub.

Published

2 days ago

October 10, 2025

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Enlight Metals has supplied 3,200 metric tonne of steel for the newly inaugurated Navi Mumbai International Airport, marking a major contribution to one of India’s largest infrastructure projects and reinforcing the company’s commitment to supporting national development.

The Navi Mumbai International Airport, developed under a Public-Private Partnership led by the Adani Group, was inaugurated today by Prime Minister Narendra Modi. The airport is set to become Asia’s largest air connectivity hub, enhancing regional connectivity, boosting economic growth, and expanding trade opportunities. Prime Minister Modi described the project as a “glimpse of Viksit Bharat,” highlighting its transformative impact on infrastructure and development in the region.

“The supply of 3,200 metric tonne of steel for this key project aligns with our focus on supporting critical infrastructure development through reliable and timely metal sourcing. Enlight Metals is committed to enhancing transparency and efficiency in the steel supply chain, contributing to projects integral to India’s growth objectives,” said Vedant Goel, Director, Enlight Metals.

Enlight Metals has implemented technology-driven solutions to strengthen supply chain efficiency, ensuring consistent availability of construction materials for large-scale projects nationwide. Its contribution to the Navi Mumbai International Airport underscores the company’s growing role in supporting India’s infrastructure development initiatives.

This milestone reflects Enlight Metals’ ongoing engagement in delivering quality materials and timely services for major national projects, further cementing its position as a reliable partner in India’s infrastructure sector