India’s shrinking carbon footprint
ICR: What are the key measures used by Indian cement companies to reduce their carbon footprint?
Dr L P Singh (LPS): Globally, the cement sector generates about seven per cent of the total anthropogenic CO2 emissions. India’s cement industry has been working on the issue of its greenhouse gas (GHG) emissions, bringing down specific CO2 emissions from 1.12t CO2/t of cement in 1996 to about 0.56t CO2/t of cement in 2023.
To reduce their carbon footprint, Indian cement companies are adopting several measures, including:
• Production of blended cements – Domestic cement companies are producing blended cements such as fly ash-based Portland pozzolana cement (PPC), slag-based Portland slag cement (PSC) and composite cement based on fly ash and slag to lower the clinker content.
• Alternative fuels – Local cement plants are utilising waste materials and by-products as alternative fuels to replace conventional fossil fuels.
• Energy efficiency – The estimated average specific thermal and electrical energy consumption of the Indian cement industry is 740kcal/kg clinker and 76kWh/t cement, respectively. The Perform, Achieve and Trade (PAT) Scheme of the Ministry of Power’s Bureau of Energy Efficiency (BEE)aims to improve energy efficiency in industries by trading in energy-efficiency certificates in energy-intensive sectors. The cement plants in PAT cycle 1 surpassed the scheme’s energy-saving targets and achieved savings of 1.48Mt of oil equivalent (Mtoe), which is around 81 per cent higher than the savings target. Similarly, the plants in PAT Cycle 2 surpassed the target and achieved savings of 1.56Mtoe, which is around 48 per cent higher than the target. These savings could be achieved by implementing advanced technologies to improve energy efficiency in cement production.
• Carbon capture technologies – Indian cement companies are considering the set-up of carbon capture and utilisation (CCU) demonstration projects.
• Waste heat recovery – Indian cement plants have installed waste heat recovery systems (WHRS) with a total installed capacity of about 600MW in 2022, increasing to ~1000MW in 2024. • Renewable energy – The cement sector is investing in renewable energy sources such as solar and wind to power operations.
ICR: How is the National Council for Cement and Building Materials (NCB) supporting India’s drive to reduce its carbon footprint?
LPS: The NCB supports the Indian cement industry’s CO2 reduction efforts through a range of measures, including:
• Research and development – Conducting R&D on development of low-carbon cements, undertaking durability studies on low-carbon systems, supporting Bureau of Indian Standards for standardisation and codal formulation, enhancing utilisation of alternative fuels, energy audits for improving energy efficiency, studies on carbon capture and utilisation, etc.
• Capacity building – The NCB has a strong team of scientists and engineers covering various streams and well-established training facilities. The association has been imparting training to cement professionals from senior level to middle/junior level and organising conferences, seminars and workshops for industry stakeholders.
• Policy advocacy – Supporting the national government and industry to promote favourable policies for green and sustainable practices.
ICR: Does India have a national Net-Zero roadmap for the cement industry. If so, what are the main 2030 and 2050/60 targets?
LPS: India has updated its Nationally Determined Contribution (NDC) submitted to the United Nations Framework Convention on Climate Change (UNFCCC) at the 26th session of the Conference of the Parties (COP26), held in Glasgow, UK, in November 2021. India presented to the world five nectar elements, known as Panchamrit, representing India’s climate action targets and comprising of the following key pledges:
• a Net-Zero target for India by 2070
• achieving carbon intensity reduction of 45 per cent, when compared with 2005 levels, by 2030
• reducing 1bnt of projected emissions from now until 2030
• installing non-fossil fuel electricity capacity of 500GW by 2030
• sourcing 50 per cent of energy requirement from renewables by 2030.
In addition, India’s leading cement and concrete companies are part of the Global Cement and Concrete Association (GCCA). In October 2021, GCCA published a Cement and Concrete Roadmap 2050 for Net-Zero Concrete. All Indian GGCA member cement companies have accepted the goal to achieve Net-Zero Concrete by 2050 and have committed to fully contribute to building the sustainable world of tomorrow.
However, in line with the national target to achieve Net-Zero by 2070, the NCB and cement companies are preparing a roadmap to achieve Net-Zero in cement by 2070.
ICR: What further support is needed by the cement sector? Please clarify the role of the government in this.
LPS: In terms of a regulatory framework, the Bureau of Indian Standards (BIS) has formulated standards on limestone calcined clay cement (LC3) in 2023 and is actively considering standardisation of other low-carbon cements such as Portland dolomite cement (PDC), Portland limestone cement (PLC), Portland composite cement based on fly ash and limestone, enhancing the limit of fly ash utilisation in PPC, etc.
In addition, research funding has been expanded. The government’s Department of Science and Technology (DST) has been actively promoting research and innovation in various sectors, including the cement industry.
To achieve the Net-Zero target, carbon capture and utilisation (CCU) is an essential area of focus, given the cement sector’s significant contribution to GHG emissions. DST has recently called for proposals to establish a 2tpd CCU test bed facility in cement plants in India. This call provided an exciting opportunity to advance research and innovation in this critical area.
Low-carbon cements
ICR: Please explain, if any, the shift in the type of building materials used in India due to the construction sector’s need to reduce its carbon footprint?
LPS: The type of building materials used in buildings has not changed much, however, there is a recent focus towards sustainable, energy efficient and green building materials. Recently, the use of AAC blocks has been the choice for building materials.
The Building Materials and Technology Promotion Council (BMTPC), under Ministry of Housing and Urban Affairs, has been promoting innovative housing technologies suitable for affordable mass housing, especially in urban areas. About 1.5m houses are being constructed with innovative housing technologies under the Pradhan Mantri Awas Yojana programme. These innovative technologies are divided into six broad categories:
1. precast concrete construction systems with precast components assembled on-site
2. light-gauge and pre-engineered steel structural systems
3. prefabricated sandwich panel systems
4. monolithic concrete construction
5. stay-in-place formwork systems
6. precast concrete construction system – 3D volumetric precast.
ICR: What is the current uptake of low-carbon cements in the Indian cement market, and what is the average clinker factor for cements sold in India? What will the market for green cements look like in 5-10 years?
LPS: In 2023 the production of blended cements in India amounted to 67 per cent of the total cement output, out of which production of PPC was ~61 per cent and production of PSC and composite cement was approximately three per cent each. The share of OPC was 31 per cent.
The production of composite cement is gaining pace in India and in the coming years the share of composite cement will further increase, subject to availability of slag in India. Cement plants are also gearing up to manufacture LC3 cement.
Going forward, the availability of fly ash will be impacted by the greening of the power sector in India and a shift towards renewable energy plants instead of coal-based thermal power plants.
ICR: Please explain the main challenges that cement producers face in terms of the use of low-carbon cement by end customers.
LPS: There is market demand for low-carbon cements such as PPC, PSC and composite cement, which are readily accepted, thanks to the efforts made by the cement industry and NCB in creating awareness among customers. The focus on green certifications of buildings has also resulted in the acceptance of low-carbon cements.
There has been a rapid growth in the production of blended cements such as PPC and PSC over the last decade. The Indian standards and codes of practices recommend PPC and PSC in plain, reinforced and prestressed concrete construction. The PSC is used against the aggressive environments of chlorides and sulphates in soil and ground water.
The use of PPC for prestressed concrete was earlier not recommended in different standards/specifications due to apprehension of late strength development, apprehension of low resistance towards carbonation-induced corrosion of steel and lack of data on other critical properties of prestressed concrete such as creep, shrinkage and fatigue. However, based on extensive research carried out at several R&D institutes in the country, BIS permitted the use of PPC in prestressed concrete by revising IS: 1343 in 2012. The use of PPC and PSC is permitted by national and international standards and specifications, including most government bodies. The use of PPC conforming to requirements of IS: 1489 is already permitted by the Ministry of Railways, Railway Board, Government of India and Indian roads Congress. Internationally, PPC is permitted for use in prestressed concrete structures, for example, in the Prestressed Concrete Institute (PCI) Manual, AASTHO specification, ASTM C-935, etc.
Commercially available PSCs in India have 50-60 per cent slag content whereas commercially available PPCs in India have 30-35 per cent fly ash content. They are used for general purpose construction for a grade of concrete of up to M50. For higher grades of concrete, customised PPC and PSC should be used with a lower share of fly ash and slag respectively. These blended cements thereafter may be used with the appropriate proportion of silica fume for the production of high strength concrete.
Alternative fuel usage
ICR: What progress is the cement industry making with regard to alternative fuel utilisation? How is the NCB supporting these efforts?
LPS: The Indian cement industry has been able to substitute seven per cent of conventional fuels on a thermal basis using alternative fuels such as refuse-derived fuels (RDFs), agro-waste/biomass and hazardous wastes such as paint sludge, sludge from textile and tannery effluent treatment plants, process waste, waste residue, chemical sludge, process sludge, phosphate sludge, insulation waste, mixed salt, organic residue, liquid organic residue, spent solvent, benzofuran and waste lubricant oil. Some cement plants have been reported to achieve a thermal substitution rate (TSR) of as high as 35 per cent. Meanwhile, the cement industry is targeting an average TSR of 25 per cent by 2030.
NCB has taken up a study on application of artificial intelligence (AI) and machine learning (ML) to enhance the TSR in a cement plant of J K Lakshmi Cement Ltd in collaboration with the start-up LivNSense GreenOps Pvt Ltd. The forecasting model developed under this study has shown potential to increase alternative fuel usage by 20 per cent when compared to the baseline level. The NCB has recently completed a project on the development of a standard chute for an alternative fuel feeding system and application of RDF gasification in cement manufacture.
Carbon capture, utilisation and storage
ICR: How and when do you view the use of carbon capture, storage and utilisation in the Indian cement industry? Please elaborate on the research and projects currently undertaken by Indian cement companies and/or research institutes.
LPS: One of the important challenges in the decarbonisation of the cement industry worldwide is to reduce the process emissions arising out of the calcination of limestone. Therefore, to achieve the cement industry’s Net-Zero target, the implementation of carbon capture, utilisation and storage (CCUS) is required. However, CCUS is still in its early stages in India. Cement companies are initiating pilot projects and collaborating with research institutes. The recent call of DST to set up pilot projects has seen the participation of major cement companies in collaboration with research and academic institutes. This demonstration project will be the first industrial-scale pilot project in the cement industry in India. In other sectors such as the power industry, some pilot plants on amine-based capture and CO2 utilisation for methanol have been set up.
Cement companies in India are also looking for international collaboration for the electrification of the cement production process. Major cement companies have collaborated with SaltX Technologies and Coolbrook’s Rotodynamic technologies.
The NCB has also undertaken a project on calciner electrification using plasma and CO2 sequestration by mineral carbonation of industrial wastes.
Key NCB research
ICR: What main research projects are the NCB currently undertaking? Could you please briefly explain their goals, methods and timelines?
LPS: The NCB has recently completed research projects to develop low-carbon cements such as PDC, PLC and Portland composite cement based on fly ash and limestone. The recommendations have been submitted to BIS for standardisation based on the outcome of these projects.
This year, the association has formed a CCU team to take up CCU research projects and as a result, the Research Advisory Committee of NCB has approved 10 new research projects. Some of the key studies focus on the electrification of the calciner, development of pre-combustion technology for alternative fuels, use of low-lime industrial wastes for CCU, utilisation of fly ash generated by co-firing of biomass in cement manufacturing, development of CO2 emission factors and a biogenic index of alternative fuels used in the Indian cement industry, development of Net-Zero Roadmap for the Indian cement and concrete sector, and mechanical and durability performance of CO2 sequestered sintered ash for lightweight aggregate in concrete. The research projects presently undertaken by the NCB are expected to be completed by 2027.
The NCB, along with IIT Roorkee and an industrial partner, is also meeting the DST call to set up a CCU pilot plant. The proposal is under active consideration by the DST.
ICR: What are the particular strengths of NCB in terms of research and development?
LPS: The NCB has a well-established research set-up with advanced laboratory equipment. The unique strengths of the NCB include its expertise. The association has a multidisciplinary team comprising of scientists and engineers in a range of disciplines, including chemical, mechanical, environmental, electrical, and geological – all with in-depth knowledge of cement technology. NCB activities cover the entire spectrum of cement production from mining and geology to concrete durability.
In addition, the organisation has a solid collaborative ethos. It fosters strong ties with academic and research institutions for cutting-edge research. The NCB has signed MoUs with the National Institute of Solar Energy (NISE) for the application of solar energy in cement manufacture, with research institutes such as CSIR for collaboration on CCU and with academic institutes such as IITs and NITs.
Moreover, the NCB’s expertise is applied to research in cement technology, where it pursues innovation and is focussed on problems faced by the cement industry. The organisation has recently filed three provisional patents.
ICR: Is the Indian cement industry/NCB taking an active role in the R&D of calcined clay and how?
LPS: LC3 has been standardised by BIS last year. Some cement plants have taken a licence from BIS to manufacture LC3. In India, IIT Delhi and IIT Madras played a key role in the R&D phase.
The NCB has undertaken a research project titled “Development of methodology for estimation of kaolinite content in Indian quality clay”. Under this study, different characterisation methods for quality control of calcined clay are being explored. The outcome of this study will be helpful to cement industry to maintain the quality control of LC3 and easily adopt the BIS standards.
ICR: What is the current status of nanotechnology in cement production in India? How do you see its progress – can you provide expected milestones?
LPS: The use of nano materials in cement and concrete is a relatively novel research area. A number of nano materials have been explored in the past two decades and they have demonstrated significant improvement in concrete performance and durability. Among the various nano materials explored, silica nano particles have demonstrated remarkable early stage strength, high performance and enhanced durability as compared to conventional/high performance concrete.
Until very recently, the cost of nano materials was of major concern to concrete technology, however, due to sustained R&D efforts this cost has now been significantly reduced and silica nano particles are now being used at commercial level for various applications in cementitious materials.
Outlook
ICR: What are the emerging trends in the Indian cement sector? How will they impact the domestic industry?
LPS: AI is increasingly being applied in the cement sector to enhance efficiency, reduce costs and improve sustainability. AI applications in the cement sector include predictive maintenance, process optimisation, predicting clinker quality, supply chain management and logistics, energy management, environmental monitoring, training and safety, and market analysis. By leveraging AI, the cement industry can achieve greater efficiency, sustainability and profitability.
ICR: How do you see the pace of demand and capacity evolving over the next five years?
LPS: The cement sector has strong linkage to sectors such as infrastructure, construction, housing, transportation, coal, power and steel. It plays a pivotal role in implementing the government’s various flagship schemes such as Bharatmala Pariyojna, construction of highways and expressways, Pradhan mantra Awas Yojana, PM Gati Shakti Initiative, Smart Cities, dedicated freight corridors, Metro projects, Clean India Mission and Inland Waterways.
India’s installed cement capacity has reached ~630Mta and the sector’s output was ~427Mt in FY23-24. Cement consumption in India is around 290kg per capita against a global average of 540kg per capita, which shows significant potential for the growth of the industry. The demand of cement is expected to see a continued growth to 550-600Mt, due to the expanding requirement of the different market segments, including housing (65 per cent), public infrastructure (25 per cent) and industrial development (10 per cent).
In its FY24-25 Union Budget, the government has allocated INR111trn (US$1.5trn), or 3.4 per cent of GDP, towards capital expenditure, focussing on infrastructure and housing. To meet this increasing demand from the infrastructure and housing sectors, underpinned by government spending, 150-160Mta of cement production capacity are expected to be added by the FY27-28.
ICR: To meet the challenges going forward, what investments and skills are required? How will the industry acquire these?
LPS: The cement industry will need investment in:
• creating infrastructure for enhancing the utilisation of alternative fuels
• adopting energy-efficient technologies
• installing waste heat recovery systems
• installing renewable energy
• carbon capture and utilisation.
In India about 99 per cent of the cement industry is in the private sector. The industry is proactively taking steps and making investment in green technologies.
The Ministry of Power is implementing the Indian carbon market, which will help in incentivising plants to make efforts towards decarbonisation and making necessary funds available to those plants.
In addition, the industry directly employs about 220,000 people. It has undergone rapid technological upgrades and vibrant growth during the last two decades and some of the plants can be compared, in every respect, with the best operating plants in the world.
A total of 88 per cent of its production is from modern pre-calcination based plants. Training the cement industry’s workforce in sustainable practices and newer technologies will be a challenge. NCB will play a major role in skill development of cement professionals.
ICR: What will it cost the Indian cement sector to reach Net-Zero?
LPS: Reaching net-zero would involve significant investments, depending on the technologies adopted and the pace of transition. NITI Aayog, Government of India, published a report on CCUS Policy Framework and Deployment Mechanism in India in 2022.
According to this report, it is estimated that INR16-18bn are required for a 2Mta carbon capture plant. Presently, Indian cement sector is estimated to emit 240Mta of CO2. NITI Aayog has now deployed a study to develop a Net-Zero roadmap and to calculate the estimated investment required to achieve the goal of Net-Zero in the industry including adoption of CCUS, renewable energy, energy efficient technologies and enhancing utilisation of alternative fuels.
This article was first published in the November 2024 issue of International Cement Review.
