Economy & Market

Optimising plant utilisation

Published

10 years ago

July 31, 2015

admin

Developments in pyro processing optimisation and technologies have made it possible to improve existing plants with high energy efficiencies and low emissions, while simultaneously reducing operating costs and preserving the environment and optimal use of fast depleting natural resources.

Kiln is said to be the heart of a cement plant, comparing the cement plant with that of human body. It is a continuous operation and the performance of a plant is judged by the number of days; the kiln runs without any stoppages. In the present economic scenario on an average, the plant utilisation is close to 70 per cent. For the operational function, it is much more challenging because if the production level further goes down for want of demand, then within no time, the plant operation runs into red. Therefore, it is extremely important to decide the equipment capacities precisely since it is a part of design. There is a tendency to go for higher capacity plants for the simple commercial considerations, but in the present situation, such plants in no time will turn into stressed asset if they are running below the bench mark level. Every unit knows its benchmark level to run it into profits. This is exactly the situation in few of the cement plants in the country as they were set up when there was a boom time for cement business which did last for few years but no further.

New approach
A few cement producers in the industry have been smart to decide on the capacities of the plant. Generally at design stage, while deciding on preheater it is preferred to have a single string of operation as a starting phase. Then after stabilisation and proper understanding of the market conditions, it is better to add another string. But then the kiln in the first phase must have been designed with sufficient margins. This has been the case with a few of plants in our country. The plant capacities have been enhanced over a period of time. Our design engineers along with FLSmidth, ThyssenKrupp, KHD Humboldt etc, have done wonderful jobs to add to the capacities of the plant in the country without diluting the performance of the kiln on any count like gaseous pollution or compromising on operational part. However, we strongly feel this has created tremendous load on the coolers and to some extent compromised its performance. The cooler as a hardware has limitations to enhance its capacity or either have modifications in the given space. In many cases, it has been noticed that it is the cooler which throttles the production and not the kiln or grinding.

Use of alternate fuels
Regarding the technology front, there is not much to say on the pyro process per se specifically that has happened in the last decade except more and more players in our country have been experimenting on alternate fuels or industrial waste which is encouraging. With more support coming from the government departments like Central Pollution Control Board (CPCB) and State Pollution Control Boards, the number of usage is only going to grow. There are some changes required in the kiln burner design before the fuels are changed or replaced. Plant would prefer to have a common burner for conventional fuel like coal and for alternate fuels like industrial waste and petcoke. The plants need to address the issue of safety while using hazardous waste since our experience in doing jobs in a safe manner is far below expectations.

Waste Heat Recovery (WHR) can reduce the operating costs and improve EBITDA margins of cement factories by about 10-15 per cent. On average, electric power expenses account for up to 25 per cent of total operating costs of a cement factory. However, to realise the full potential of WHR as of now $1,400 million is required, which is too high.

The other major advantage for Indian cement industry is minuscule presence of volatile matters like sulphur, chlorine, potassium etc. Therefor a majority of plants in India do not have bypass system as a part of design whereas the plants in Gulf countries have this as an additional system. In future as more and more plants will go for alternate fuels in the country they may have to go for by pass system as additional feature.

Focus emission
In pyro processing, the area of focus has been, reduction of NOX and SO2 emissions, and increase of production throughput without compromising on energy consumption but with flexible options on fuel.

Safety in pyro processing is extremely important since coal is used as a fuel. Generally, it is pulvisised at the plant and then fed into the kiln through burner. The conditions in the coal mill area are extremely hazardous and need more attention to reduce the number of unsafe incidences. Inertisation of coal mill is yet to be executed in many plants. There is a lot of scope for improvement here in the industry. Considering the capabilities exhibited till date, we feel Indian cement industry will fulfill this aspiration as well.

Conclusion
According to Kumar, developments in pyro processing optimisation and technologies have made it possible to improve existing plants with high energy efficiencies and low emissions, while simultaneously reducing operating costs and preserving the environment and optimal use of fast depleting natural resources. Process optimisation and performance improvement has become inevitable in cement industry. "Although every situation must be analysed carefully to evaluate real gains that can be achieved, most cement plants can achieve improved performance by implementing suitable modifications," he concludes.

TECHNOLOGY TRENDS IN PYRO PROCESSING

Kilns

Redefinition of operating parameters – volumetric loadings up to 7.5 tpd/cu m
Thermal loadings up to 5.5 Gcal/ sq m/kg clinker
Filling % of 14-16 and kiln speeds up to 5.5 rpm
2-pier installations with a drop in L/D ratios to 10-11
Low primary air, low NOx multi-channel burners

Pre-calciners

Degree of calcination up to 95 per cent
Calciner to kiln fuel ratio of 70:30
Increased residence time up to 5.5 sec to improve combustion efficiency specially in case of petcoke
Low NOx systems Pre-heater
6-stage, twin string preheaters with clinkering capacities up to 10,000 tpd
Increased cyclone efficiency up to 96 per cent
Reduction in L/D ratio in cyclones resulting in a pressure drop reduction from 700 to 400 mm WG and a tower height reduction of 10-15 m
Reduction in the total sp. air requirement from 1.6 to 1.45 Nm3/kg clinker Improvement in fan efficiencies.

Coolers

New generation (eg, walking-floor) coolers resulting in increased cooler recuperating efficiency from 68-76 per cent resulting in increase of secondary/tertiary air temperature to 1,000oC
Drop in air requirement from 2.2 to 1.6 Nm3/ kg clinker
Increase in cooler loading up to 50 t/d/sq m

Bypass system
Raw materials and fuels used for the manufacture of clinker generally contain some volatile constituents. These are mainly the compounds of potassium, sodium, sulphur and chlorine. Volatiles may also originate from water, refractory and wearing parts of equipment. These volatile constituents generally have low melting points. Hence, condensation of the volatile matters takes place on raw meal particles and the surrounding walls in the colder zones of the kiln. This causes build-ups on the cyclone walls and riser ducts that lead to blockages in the passage areas in the cyclones. The bypass system allows a high proportion of volatiles to be removed through the kiln gas stream and improves the performance and product quality.

Fuel solutions
Alternative fuels such as lignite, petcoke, tyres, bagasse, rice husk, industrial wastes etc, are being in use for sometime now. Several plants are using/ investigating hospital refuse and municipal waste as workable alternatives. The current reported thermal substitution rates (TSR) in the Indian cement industry is about one per cent. However, TSR levels as high as 60 per cent have been achieved in some of the developed nations. Action plans are needed to overcome technical, financial and regulatory barriers to the growth of alternate fuel (AF) usage. Technical solutions are in place for storage, handling and dosing the AF to the system.

– Kamal Kumar, Chief General Manager, Holtec

Diagnosis
Based on process measurements conducted following observations were made:

The PH system is operating with about 28% leakage air. This is resulting in higher PH fan power consumption.
The cooler vent gas volume of 1.63 Nm3/kg clinker and temperature of 369oC.
High clinker temperature of 165oC value against the normal value of around 100oC.
The heat balance of the pyro processing system indicated that the total heat consumption works out to 888 kcal/kg clinker.

Implementations
Following suggestions were implemented:
Area	2,000 t/d
Kiln size	3.95 m dia x 56 m L
Preheater (PH)	Single string 5-stage suspension preheater with in line calciner (ILC)
Kiln burner	Duoflex
Fuel used	Furnace oil
Preheater fan	7,000 m³/min at 900 mm WG, 320^oC
Cooler vent fan	5,133 m³/min at 190 mm WG, 300^oC
Clinker cooler	Reciprocating grate cooler
Cooler effective area	52.8 m²
No. of grates	2
Specific heat consumption
(A mass and heat balance conducted jointly)	854 kcal/kg clinker

Implementations
Following suggestions were implemented:
Area	Recommendations	Result
Fuel firing	Conversion of oil firing to coal firing in kiln and PC	Reduction in operation cost
Preheater	Reducing preheater exhaust gas quantity to 1.60 Nm³/kg clinker by arrest false air leakage, reduce the PH outlet draft	Reduction in heat consumption
	PC primary air fan volume reduced, smaller capacity fan motor installed	Reduction in power consumption
	Coal transport air quantity to PC was reduced in phases	Reduction in heat consumption
	Maintaining PC outlet temperature as 840^oC.A PID loop was provided for the PC firing.	Reduction in heat consumption
Kiln	Increase the kiln speed from 3.0 to 3.3 rpm	Increased kiln output
	Coal transport air to quantity to kiln was reduced in phases	Reduction in heat consumption
	Position of the inner burner pipe was retracted by 30 mm and pressure at burner pipe was increased by 10 per cent	Sharp and intense flame resulting in saving in heat consumption
Clinker cooler	To reduce the cooler vent air temperature	Reduction in heat consumption.
	Optimisation of cooler operation, commissioning of water spray system.	Reduction in clinker temperature
	First grate of the cooler is to be modified with the new generation static grate plates/grate systems.	Improved heat recuperation to handle increased clinker production
		Stable cooler operation

Concrete

The primary high-power applications are fans and mills

Published

2 weeks 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 weeks ago

October 10, 2025

admin

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

Digitalisation is pivotal in driving energy efficiency

Published

2 weeks ago

October 10, 2025

admin

As energy costs continue to dominate the cement industry, efficiency and sustainability are proving to be vital components. MM Rathi, Joint President, Power Management, Shree Cement, explains the company’s long-term strategy is focused on cutting emissions while powering growth with renewable energy solutions.

Energy efficiency has always been a cost-saving lever for the cement industry. Today, it is the backbone of sustainability and competitiveness. Cement manufacturers are under growing pressure to optimise consumption, diversify power sources and align with decarbonisation targets. Shree Cement has been at the forefront of this transformation, significantly scaling up its green power capacity and embedding advanced technologies across operations. In this exclusive conversation, MM Rathi, Joint President – Power Management, Shree Cement, shares insights on the company’s approach to energy efficiency, challenges in brownfield modernisation and long-term strategies for achieving net zero alignment.

What percentage of your total operational cost is attributed to energy consumption?
At Shree Cement, energy is one of the most significant components of production cost, accounting for nearly 30 per cent to 40 per cent of total operational expenses. Within this, thermal energy typically contributes around 20 per cent to 25 per cent, while electrical energy forms about 10 per cent to 15 per cent. The exact share varies depending on factors such as the fuel mix (coal, pet coke or alternative fuels and raw materials), the power source (grid-based or captive like solar, wind or thermal), raw mix quality, and regional fuel and electricity price variations. This makes energy efficiency and the adoption of sustainable power sources a key focus area, both from a cost and sustainability perspective.

How has your company improved energy efficiency over the past five years?
Over the past five years, Shree Cement has consistently invested in enhancing energy efficiency across operations. Our green power capacity, covering wind, solar and Waste Heat Recovery (WHR), has more than doubled from 245 MW in 2020 to 592 MW in 2025. All grinding units are now equipped with biomass firing facilities, reducing dependence on conventional fuels. From the project stage itself, we prioritise efficiency by selecting advanced technologies such as six-stage kilns with integrated WHR, CFD-designed plants, and equipment fitted with VFDs, centrifugal compressors and high-efficiency fans. We also review and upgrade equipment systematically, replacing fans, compressors, blowers, pumps, boilers and turbines with more efficient options. This continuous approach has reduced costs while significantly advancing our sustainability journey.
What technologies or practices have shown the highest energy-saving potential in cement production?
WHR stands out as one of the most effective solutions, offsetting a significant portion of electricity required for clinker production. Hot air recirculation has also proven highly beneficial in reducing heat losses. Additionally, regular energy audits help us identify opportunities for improvement and implement corrective measures in daily operations. Together, these practices play a critical role in optimising energy efficiency and driving sustainable operations.

What are the key challenges in adopting energy-efficient equipment in brownfield cement plants?
The biggest challenge is the significant upfront investment required for upgradation. Retrofitting existing facilities often involves complex civil and structural modifications, which add costs and extend downtime. Integration is another hurdle, as new high-efficiency equipment may not align seamlessly with older kiln systems, fans, mills or automation setups. These factors make the transition in brownfield plants more resource-intensive and time-consuming compared to greenfield projects.

How do you measure and benchmark energy performance across different plants?
We track key performance indicators such as specific heat consumption and specific power consumption for each unit, benchmarking them against internal and external standards. Thermal Substitution Rate (TSR percentage) is another critical metric, measuring the share of alternative fuels in the thermal energy mix. Internally, we benchmark performance across plants to encourage best practice sharing. Externally, we compare against national averages and align with the Bureau of Energy Efficiency’s PAT (Perform, Achieve, Trade) scheme, which sets Specific Energy Consumption (SEC) baselines and targets for cement plants. This multi-layered approach ensures continuous monitoring, improvement, and industry leadership in energy efficiency.

What role does digitalisation play in achieving energy efficiency in your operations?
Digitalisation is pivotal in driving energy efficiency at Shree Cement. IoT sensors integrated with SCADA and DCS systems allow real-time monitoring of parameters like heat consumption and energy use, moving beyond periodic reports. Our digital platforms consolidate plant data, enabling management to compare metrics such as SPC, SHC, kWh per tonne and kcal per kg across units in real time. This visibility supports data-driven decisions, faster corrective actions, and higher operational efficiency.

How do government policies and incentives influence your energy-saving decisions?
Government policies and incentives strongly shape our energy-saving decisions. The Perform, Achieve, Trade (PAT) scheme sets plant-specific SEC targets. Non-compliance incurs penalties, while compliance earns tradable energy-saving certificates. This ensures energy efficiency is both cost-driven and regulatory. Additionally, subsidies and viability gap funding for renewable energy projects in wind, solar and AFR co-processing help reduce payback periods and make energy-saving investments more viable.

What is your long-term strategy for aligning energy efficiency with decarbonisation goals?
Our long-term strategy aligns energy efficiency with India’s net zero 2070 goals. Key levers include improving efficiency, expanding green electricity, producing more blended cement, and increasing alternative fuel use. Today, more than 60 per cent of our electricity comes from green sources such as solar, wind, and WHR, the highest in India’s cement industry. Our blended cement products, which reduce limestone and fuel consumption, further lower emissions. These products are certified under the GreenPro ecolabel by CII, validating our sustainability practices and environmental standards.