Asok K Dikshit, Richa Mazumder, Sanjeev K. Chaturvedi and LP Singh, National Council for Cement and Building Materials (NCB), give a detailed account of the technological changes that are leading the Indian cement industry towards a sustainable and environmentally conscious growth path.

The role of technology in achieving sustainability in cement plants is instrumental as it is already facing sustainability issues due to a number of factors like energy and water consumption, material and resource management, reduction in greenhouse gases (GHG) emissions, waste management, etc. The cement sector is under increasing pressure to adopt innovative technological solutions that balance economic growth with environmental responsibility. In this context, various technological advancements have emerged to achieve sustainability goals in cement manufacturing.
The driving technologies to achieve sustainability in the cement sector are advanced process control systems powered by artificial intelligence (AI) and machine learning (ML), real-time monitoring and optimisation of production parameters and the application of Industry 4.0 in cement plants, which is proving to be a transformative force, propelling the industry toward greater sustainability. Industry 4.0, characterised by the integration of digital technologies, automation and data-driven processes, addresses the complex challenges associated with cement production. Carbon capture and storage technologies address the significant carbon footprint of cement production. Digital twins and simulations allow for virtual testing and refinement of processes, minimising trial-and-error approaches and identifying opportunities for efficiency improvements. Emission monitoring and control technologies, including continuous monitoring systems and advanced sensors, ensure compliance with environmental regulations and contribute to improved air quality. Circular economy practices are enhanced through technology, supporting the recycling and reuse of by-products and optimising material flows. Water management is made more sustainable through automated systems and AI-driven analytics, minimising the industry’s impact on water resources. Stakeholder engagement and transparency are facilitated by digital platforms, fostering collaboration and awareness about sustainability initiatives. Remote monitoring and maintenance technologies reduce the environmental footprint associated with on-site activities. Thus in this paper, driving technology that promotes efficiency, reduces environmental impact, and contributes to a more responsible and resilient industry has been discussed in detail.

Optimising technology
Cement manufacturers should strategically incorporate key technologies to enhance operational efficiency and product quality to meet sustainability goals. The application of Industry 4.0 in cement plants represents a transformative shift towards intelligent, interconnected, and data-driven manufacturing [1-2]. This concept involves the integration of advanced digital technologies to optimise various facets of cement production. Smart sensors and the Internet of Things (IoT) are strategically deployed throughout the plant, providing real-time data on equipment performance, energy consumption, and environmental conditions. Automation and control systems, equipped with artificial intelligence and machine learning, enable advanced process control, ensuring precise monitoring and adjustment of production parameters. Digital twins, virtual replicas of physical processes, facilitate simulation and optimisation, allowing for testing and refining of operations in a virtual environment. Big data analytics processes the vast amounts of data generated during production, offering valuable insights for decision-making and continuous improvement. By the implementation of Industry 4.0 Cement production can in a number of ways as shown in Fig. 1.
Equipping cement industry with innovative technologies positions enables them to thrive in the evolving industrial landscape, embracing efficiency, quality, and sustainability. In driving sustainability in the cement industry technology plays a crucial role by enabling more efficient processes, improving overall resource management and reducing environmental impact. Here are several ways in which technology contributes to sustainability in the
cement industry:
Energy efficiency: Technology plays a pivotal role in enhancing energy efficiency in cement plants, a sector known for its substantial energy consumption. Data science is often used in the energy optimisation area. Advanced process control systems, powered by machine learning and artificial intelligence, are positioned to optimise the intricate processes involved in cement production by suggesting the most efficient operating conditions for equipment, thereby reducing energy costs and environmental impact. Digitalisation allows for better monitoring of equipment’s energy consumption. Cement industry can take corrective actions to reduce energy wastage and carbon footprint by identifying the energy consumption patterns of equipment under faulty conditions, thereby achieving significant cost reductions over time [3]. Furthermore, technology makes possible the integration of waste heat recovery systems, capturing and repurposing thermal energy generated during the production process.
Alternative fuels and raw materials: The cement sector is responsible for a significant portion of greenhouse gas emissions and is one of the largest consumers of energy globally. The use of alternative fuels, such as biomass, waste materials and municipal solid waste, can reduce the reliance on fossil fuels, bring down greenhouse gas emissions, and will enhance energy efficiency. This has been made possible by progress in technology, including the development of specialised equipment for handling and processing these fuels. For example, rotary kilns can be modified to handle different types of fuels, and preheaters can be designed to optimise the combustion of alternative fuels as shown in Fig.2.
The use of alternative fuels also has economic benefits by reducing the cost of energy and raw materials, and providing opportunities for waste reduction and recycling. Automation technologies ensure precise dosing and combustion of alternative fuels, promoting cleaner energy sources and reducing the industry’s reliance on fossil fuels.
Carbon Capture, Utilisation and Storage (CCUS): Addressing the significant carbon footprint associated with cement production requires innovative solutions, and technology provides a pathway through carbon capture, utilisation and storage (CCUS). These technologies contribute to the industry’s efforts to decarbonise and mitigate its environmental impact. CCUS technology captures CO2 emissions from cement plants and stores them underground or uses them in other industrial processes.
It has several benefits, which include
(a) the reduction of greenhouse gas emissions,
(b) improved energy efficiency, and
(c) the creation of new revenue streams.
However, carbon capture, utilisation and storage technology is still in the initial stages of development, and significant investment is required to make it commercially viable.
Digital twins and simulation: The concept of digital twins, virtual replicas of physical processes and equipment, is gaining prominence in the quest for sustainability in cement manufacturing. In the cement sector the digital twin can allow the cement manufacturers to effectively mirror their production process through a well-designed digital model, and then they can optimise it by using machine learning and artificial intelligence. The digital twins can imitate the cement production process in a dynamic as well as simplified way. As a result, it can create scenarios that can effortlessly change with variables. The finest part of the digital twin is that it can suggest optimal and efficient equipment configurations that can help to increase output target [4].
Emission Monitoring and Control: Continuous monitoring of emissions is critical for regulatory compliance and sustainable practices. Technology, such as continuous emission monitoring systems (CEMS), provides real-time data on air pollutants generated during cement production. AI algorithms analyse this data to detect patterns, identify sources of emissions and optimise control mechanisms. Advanced sensors and monitoring devices ensure the effective operation of emission abatement technologies, such as electrostatic precipitators and selective catalytic reduction (SCR) systems as shown in Fig.3. These technologies contribute to improved air quality and reduced environmental impact, aligning with the industry’s commitment to sustainability[5].
Circular economy practices: Incorporating circular economy practices is essential for minimising waste and optimising resource use in cement production. Technology facilitates the recycling and reuse of by-products, such as fly ash and slag, in cement manufacturing. Automation systems streamline the collection and processing of these by-products, reducing reliance on primary raw materials. AI and ML algorithms optimise material flows, identifying opportunities for waste minimisation and resource recovery. Blockchain technology enhances transparency in the supply chain, verifying the authenticity and sustainability of raw materials sourced from various suppliers. By embracing circular economy practices, cement plants contribute to resource conservation and environmental sustainability.
Water management: Sustainable water management is a crucial aspect of cement plant operations, particularly in regions facing water scarcity. Technology aids in the implementation of water-efficient processes and recycling systems. Automated control systems adjust water usage based on real-time needs, and sensor-based technologies monitor water quality. AI-driven analytics help identify opportunities for water conservation and improve overall water management strategies. By optimising water usage and implementing advanced technologies, cement plants mitigate their environmental impact on water resources and contribute to sustainable water stewardship [4-5].
Stakeholder engagement and transparency: Technology enhances stakeholder engagement and transparency, fostering collaboration between cement manufacturers, suppliers, regulators, and local communities. Digital platforms and communication tools enable efficient and transparent communication about sustainability initiatives. Social media and online platforms provide avenues for sharing information and engaging with stakeholders, creating awareness about the industry’s commitment to sustainability. Technology ensures that stakeholders are informed about environmental practices,corporate responsibility, and progress towards sustainability goals. This transparency builds trust and accountability, essential elements for achieving long-term sustainability objectives.
Remote monitoring and maintenance: Advancements in connectivity and remote monitoring technologies offer opportunities for optimising maintenance strategies and reducing the environmental impact associated with on-site activities. Remote monitoring allows for off-site monitoring of equipment and processes, providing real-time insights into performance as shown in Fig.4. Predictive maintenance strategies, facilitated by AI and ML algorithms, optimise equipment performance and extend the lifespan of machinery. By leveraging remote monitoring and maintenance technologies, cement plants enhance operational efficiency, reduce downtime and minimise the environmental footprint associated with traditional maintenance practices.
Future trends and challenges: While current technologies contribute significantly to sustainability in cement plants, future trends and challenges are shaping the industry’s trajectory. Advanced robotics, for example, are being explored for hazardous tasks, reducing risks to human health and safety. Integration of AI into supply chain management is expected to optimise logistics, reduce waste and enhance overall efficiency. Additionally, the industry is exploring innovative low-carbon and carbon-negative cements as part of its commitment to achieving net-zero emissions. However, challenges such as the initial capital investment required for technology adoption and ensuring alignment with local regulatory frameworks must be addressed to realise the full potential of these advancements.

Conclusion
In conclusion, technology is a driving force in the journey towards sustainability in cement plants. From energy-efficient processes and alternative materials to carbon capture and circular economy practices, technology is instrumental in reshaping an industry with historically significant environmental impact. Cement manufacturers are embracing innovative solutions, leveraging AI, ML, and other digital advancements to enhance operational efficiency, reduce carbon emissions and minimise resource consumption. As the industry continues to evolve, the integration of technology will play a central role in achieving the delicate balance between economic viability and ecological responsibility. Cement plants that invest in and implement these technologies not only ensure their long-term competitiveness but also contribute to a more sustainable and environmentally conscious future
Acknowledgement: The authors wish to acknowledge the Director General of National Council for Cement and Building Materials (NCB) for giving permission for publication and DPIIT, Ministry of Commerce and Industry, GOI through various R&D projects support financial for sustainable development of cement industry. They also acknowledge all scientific and technical staff of NCB for cooperation through R&D work for sustainability of cement industry related projects.
Conflict of interest: The authors have no conflicts of interest financially and ethically to publish in this review work.

References

1. The 21st-century cement plant: Greener and more connected, September 16, 2020 | Article, McKinsey & Company Eleftherios Charalambous, Thomas Czigler, Ramez Haddadin, and Patrick Schulze
2. Why Cement Producers Need to Embrace Industry 4.0, Article, December 07, 2018, Sumit Gupta, Suresh Subudhi, and Ileana Nicorici
3. Article, Exclusive Interview: Nanoprecise Co-Founder Talks about the Importance of Technology in Cement Production, Prashant Verma, Date: 23-08-2023, Place: Delhi, India
4. ECUBIX, Blog, why do Cement Producers Need to Accept
   Industry 4.0?
5. ClipOn, Article, Advanced Tech to Improve Efficiencis in Cement Plant Emissions March 02, 2023

ABOUT THE AUTHOR:
Ashok K Dikshit, General Manager, NCB has over 28 years rich R&D experience.

Richa Mazumder, Manager, NCB has 13 years of experience in the field of geology, mining, raw material, and waste utilisation in cement manufacturing.

Sanjeev K Chaturvedi, Joint Director, NCB, has over 37 years of experience in the areas of research planning and execution.

LP Singh, Director General, NCB, has over 30 years of work experience committed towards advancing scientific knowledge and translating research into practical applications.