What are the main AFR materials you are using in your plants in India?
Cement is a necessary commodity to build a resilient infrastructure. It is a necessary product and our efforts shall continue to reduce its negative environmental impacts. Conservation of resources though use of alternative raw materials is our key focus. We use fly ash (waste from thermal power plants) and BF slag (waste from steel industry) in our blended cements which is nearly 80 per cent of our product portfolio. Our alternative raw material consumption rate has more than doubled from 14.5 per cent in 2013-14 to 30 per cent in FY 2017-18. Portland Slag Cement (PSC) and Portland Composite Cement (PCC) collectively contribute to nearly 50 per cent of our product portfolio. Our clinker factor has come down to 63 per cent at current levels from about 81 per cent in 2013.
Similarly, on group level we reached 4 per cent Thermal Substitution Rate (TSR) as compared to nearly 0.5 per cent five years back. We also developed pockets of excellence in some plants where nearly 18 per cent TSR was achieved. Presently we are suing various alternative fuels such as biomass, tyre nylon threads, carbon black, plastic wastes, footwear waste, spent wash, paint sludge, cotton waste, spent carbon, saw dust, etc. It adds to our profitability, and at the same time, reduces the GHG emissions from cement operations. Moving forward, we are strengthening our fuel feeding systems further with investments to make more use of both solid and liquid alternative fuels.
To what extent Indian cement companies are exploiting AFR compared to global benchmarks?
In recent years, Indian cement industry has made significant investments towards ensuring a greener future, as well as enhanced use of alternative fuel and raw materials (AFR). Although there is development on infrastructure and facilities for alternative fuels under our control, strengthening our teams and advocacy to make conducive environment for alternative fuel use will also depend on the progress of overall waste management sector in India.
The progress on the front of alternative raw materials has been very good in India. There has been a very good penetration of blended cements in the market. Earlier OPC used to be the market leader in India. However, today, it represents only about 20-25 per cent of the market share. In this context, it is encouraging to note that nearly 75 per cent of cement production in India at present is in the form of blended cement of various types, as against only 30 per cent in 1999-2000.
What is the level of energy efficiency you have achieved through AFR?
Alternative raw materials can be considered key contributors to the energy efficiency as they replace the virgin raw materials and avoids the process energy needs for the cement production to the extent of their use. Clinker, the most energy intensive intermediate product, when replaced with fly ash or blast furnace slag (wastes of thermal power and steel industry respectively), it helps in avoidance of primary and secondary energy consumption of clinker manufacturing. Therefore, the specific energy intensity of cement reduces with the use of alternative raw materials. Besides, technological advancements in cement sector from Indian industry, use of waste materials in process has helped us to become highly energy efficient. The best cement plants operating in India have a specific power consumption range from 62-70 kWh/tonnes of cement as compared to global average of above 100 kWh/tonnes of cement.
Alternative fuels, on the other hand, reduces the energy efficiency. There are energy losses due to high moisture content and inconsistent fuel quality. The production loss also takes place with use of alternative fuels in high quantities. However, on the positive side, the waste (hazardous or non-hazardous) gets eliminated in the high temperature zone of the kiln and avoids the fossil fuel burning.
What are the challenges companies face in sourcing AFR materials, and what are the strategies do you follow?
Indian cement industry has more potential to use both alternative fuels and alternative fuels than being used currently. In order to achieve this, a complete transformation is needed in the waste management sector in India from generation point to disposal methods. The circular economy principle shall be the backbone of the waste management practices in India.
There are some positive changes on policy development as well such as ôSwachh Bharat Missionö (i.e. Clean India Mission), Plastic Waste Management Rules 2018, relatively quick co-processing approvals and lot more needs to be done on policy framework. The key change would be landfill tax or similar polluter to pay mechanism to progress on circular economy concept.
New cement types, additives and technological advancement, more particularly in blending, would be needed to reach such high levels of clinker factor optimisation. Recently we launched the Portland Composite Cement (PCC) which is nearly comparable to Portland Slag Cement (PSC) in its low clinker factor. Considering production of PSC and PCC are limited by the availability of BF Slag, we have partnered with The +cole polytechnique fTdTrale de Lausanne (EPFL), Switzerland and IIT Delhi for development of LC3 cement. This will allow us to produce high blend cements even in locations where BF slag is not available.
There has been an overwhelming customer response towards adoption of environment friendly products. Similarly, many states have come forward and developed policies towards more utilisation of blended cements. On our part, we continue to do the policy advocacy and training of masons towards more use of blended cements by making them sensitive to the environmental challenges such as climate change. Use of industrial wastes in cement gives technical advantages of improved durability and reduced Carbon footprint.
The incorporation of supplementary materials like fly ash or slag in blended cements makes the concrete more impermeable and hence durable under aggressive exposure conditions. The various technical advantages of such concretes like, higher later-age-strength, lower heat of hydration, and, higher resistance to aggressive agents like chloride, sulphate and alkali, have been amply proven by many studies the world over. Rightly, the industrial wastes or by-products are no longer treated as wastes in the context of concrete technology. Due to value addition by their use, these have become friendly and in fact, necessary supplementary materials in cement.
In terms of cost and earnings, how beneficial is this for your company?
Being one of the highest profitable cement company in India, we also a market leader in alternative raw material consumption and progressed well in alternative fuel consumption as well. It proves there is a strong correlation between use of AFR and increasing the business profitability.
What are the factors to be studied while buying AFRM equipment?
It depends on the requirements. Sometimes a local solution can be the best fit and in other cases, sophisticated technology with high investment may be needed. The overall plant infrastructure, alternative raw material and fuel type, physical properties, quantities available, etc. are some key parameters which need careful consideration before buying the AFRM equipment.