Cement industries can certainly play a key role in promoting better waste management practices and create a win-win situation by working with urban local bodies on waste segregation and management of municipal solid waste.
The Indian cement industry, as indicated by CII, is second largest in the world, it has set voluntary and ambitious emission reduction targets to reduce 45 per cent of its carbon emissions intensity by 2050 from the 2010 levels. As one of the global leaders in energy efficiency, the Indian cement industry has also committed to reduce 377 - 485 PJ of energy in 2050 compared to BAU scenario. This is a clear testimony on how the Indian cement industry is keen to make a difference.
Moreover, the Government has committed to reduce emissions intensity of its Gross Domestic Product (GDP) by 33 to 35 per cent by 2030 from 2005 level. The cement industry, being one of the major contributors to the Indian economy, can play a vital role in supporting the nation in its low carbon pathway.
The potential to reduce emissions from cement is significant, since a 1 per cent increase in thermal substitution rate (TSR) will result in reduction of 2-3 kg CO reduction/ tonne of cement.
It has been proven beyond any doubt that, in a cement kiln, the organic constituents of fuel are completely destroyed and the inorganic constituents combine with the raw materials and exit as part of the cement clinker without generating solid residues, thus providing the best solution for waste management. The use of alternate fuels and raw materials reduces carbon emissions that result from using fossil fuels and reduce the overall environmental impact of cement manufacturing process.
As rightly indicated by CII, Indian cement industry has been steadily progressing in AFR substitution over the years. There had been remarkable changes in last 10 years on this subject of AFR in India. The thermal substitution has shown a very positive trend year on year, though at a very slow pace earlier and picking up later in last two to three years to a level of around 4-5 per cent. If you look at the volumes of waste used, the Indian cement industry is fourth in the world with use of 1.6 million tonne (MT), with Germany being the highest with 3.1 MT, followed by North America with 2.2 MT and the US with 1.9 MT. However in terms of TSR, we are still hovering around 4-5 per cent. AFR TSR increased from 0.6 per cent in 2010 to 4 per cent in 2016. The number of cement plants using AFR has increased from 12 plants in 2010 to 59 plants in 2016. This 4 per cent TSR accounts to 1.6 MT of alternate fuel usage in Indian cement industry and the current level of AF substitution saves 1.1 MT of coal per annum, saving costs of Rs 3,420 million. This gives an idea of the potential that exists in AFRM usage in Indian cement industry.
The basic reasons for this low TSR can be broadly assigned to lack of knowledge on AFR usage in Indian cement industry in the early years, especially on usage of industrial waste, lack of skilled persons for handling and usage of industrial wastes, lack of proper infrastructure for storage and feeding of AFR materials to cement kilns, lack of proper understanding on the permitting process in regulatory bodies and above all, the will to receive and use the waste materials in cement plants. In the last two years, remarkable transformation has been noticed on all the above aspects with dramatic changes in the mindset of regulatory bodies, the plant operating professionals and also of waste generators who are shifting to co-processing as a better option over landfilling and incineration as it provides a cost-effective option to them.
The market drivers for this change in mindsets of cement industry is mainly because the cost of fuel is continuously increasing, severely affecting the operating margins of the cement manufacturers. With increasing demand for cement, AFR usage becomes a key to reduce fossil fuel and raw material consumption and cost.
India's cement sector, being one of the eight core energy intensive sectors, is a part of PAT scheme (Perform, Achieve and Trade), launched under the National Mission to Enhance Energy Efficiency (NMEEE). The cement industry has been one of the major contributors to energy reductions in PAT Cycle 1, having surpassed its targets by more than 80 per cent. Considering that latest technologies for energy reduction including waste heat recovery systems (WHRS), grinding systems etc., which are being widely adopted, one of the main levers to achieve PAT targets in the future is increasing AFR substitution in cement kilns.
Waste management is a growing concern for India. The Government of India is attempting to tackle this challenge through a number of activities and programmes, including the Clean India Mission. Cement industries can certainly play a key role in promoting better waste management practices and create a win-win situation by working with urban local bodies on waste segregation and management of municipal solid waste. Substantial fractions of industrial, commercial, domestic and other wastes contain materials that have the potential for use as an alternative raw material or as a supplementary fuel for energy recovery in cement kilns.
This concept of co-processing is now well understood by the cement Industry, but still this scope and understanding in the waste generators is lacking and needs to be elaborately explained and understood by the waste generators.
The waste generators need to understand that co-processing is a proven sustainable development concept that reduces dependency on natural resources, reduces pollution and landfill space, thus contributing to reducing the environmental footprint. Co-processing is also based on the principles of industrial ecology, which considers the best features of the flow of information, materials, and energy of biological ecosystems, with the aim of improving the exchange of these essential resources in the industrial world.
AFR can be used alone also as fuel in cement kilns. A proper understanding of the processes, raw material characteristics and the waste compositions are the key factors that need to be assessed before use of AFR in a particular kiln system. At a cement plant, for creating systems for preparation of a homogenised raw mix that is fed to a kiln, we make a lot of investment. But the same understanding is lacking when we need to create facilities for improving AFR usage in the plant. The cement plants also need to know the characteristics of the waste that is to be co-processed and its compatibility to the raw material being used, to avoid process fluctuations and avoid kiln operating instabilities.
Normally, during the preliminary visit to the waste generators itself one should try to understand the waste characteristics, the waste material safety data (MSD), etc.
Proper samples are to be collected for analysis and reviewed if the waste is co-process-able or not. During the proposal and agreement finalization with the waste generators this aspect is considered for defining the quantities that are usable in the plant and define the safety aspects of the waste. Finger printing analysis is need to be done later to asses that the waste is in line to the agreement and safe to be handled, stored and used in the required proportion that will not affect the product quality and the environment.
In the plants that are utilising higher quantities of wastes it is desirable to have a proper waste finger printing analysis laboratory. Moreover, in plants that are utilising different types of waste it is also desirable to have a proper pre-processing facility for feeding a uniform quality of processed waste to the kiln system. Based on the quality of this processed waste suitable changes in the raw material composition can be done to ensure that required balances in the material characteristics is effected before material gets fed to the kiln system, for ensuring steady operation of kiln and uniform quality of desired product. A few third parties are also looking into creation of such pre-processing facilities for supply of processed waste to cement plants.
Many a time, investment on creating facilities at cement plant are made without proper understanding of waste available in the markets and its availability resulting into idling of the created facilities. There are a number of Indian as well as imported suppliers who can supply the required installations, but cement plants need to know what type of equipment is to be installed based on the market data of wastes available. Secondly, the concept of "POLLUTER TO PAY" needs to be imbibed into the waste generating industries to have a win-win situation. Unless these aspects are well understood, investing blindly may lead to lower returns on investment and frustration in the operating personnel at the cement plants.
Finally, to conclude it is imperative to know that Co-processing can offer a local and desired route to manage wastes with minimum liability and environmental impact addressing all the requirements of sustainable development and help reducing our energy demand from natural resources. Hence now it is time to know that there is urgent need for adopting co-processing of wastes as AFR in cement kilns, for managing our businesses efficiently in the country.
About the author:
Milind Murumkar, Advisor & Consultant for AFRM. He is operating as an advisor and consultant for improving the AFR usage in Indian cement industries, and enabling the cement industries as waste management solution provider for all sectors for sustainable waste management solutions. Earlier he had been successful in bringing regulatory changes in the waste management regulations, etc. with advice and support of CPCB & MOEF. Working for the betterment of waste management techniques, he is keen on developing this concept in schools and young people for a better and clean India.
Murumkar is presently associated with Orient Cement, Shree Digvijay Cement and Toshaly Cement as an advisor and consultant.
He is retired as senior general manager at ACC Limited, working with ACC for last 36 years in all disciplines, including quality control/ assurance, process engineering, procurement, logistics and co-processing of waste in cement kilns. He had developed this concept of co-processing of waste in cement kilns in 2006 along with other two seniors that has taken wings of change in last 10 years.
For three years post retirement, he has worked as an advisor to Vicat in India from 2015 to 2018. He can be contacted on: Mob: +919100960039 | 919004476333 or firstname.lastname@example.org.