CEE Jan-Mar 2012

the total coal produced as fuel in kilns only. This provides for only around 80 per cent of its fuel requirement. It is expected that at the present rate of coal consumption , the coal reserves in India will be exhausted in the next 70 years. It is therefore important to look for alternatives. At the same time, it is imperative for all corporations to fulfill their social commitment towards sustainability by reducing consumption of fossil fuels and greenhouse gas emissions. The Indian cement industry's use of alternative fuels is miniscule. Listed here are a few of the alternatives to coal which can decrease the use of coal as a fuel to a certain extent. Fuel alone account~ for about 40 per cent of the cost incurred by the cement industry. Plastic waste: India generates at least a lakh tonne of plastic waste a day. Many of the plastic wastes generated cannot be recycled . These wastes can be used in cement kilns for manufacture of clinkers. The problem over here is that in India plastic waste is not segregated and it gets mixed with solid waste. ACC Ltd has signed and MoU with Goa government for establishing a collection and segregation mechanism for plastic waste from non-biodegradable solid waste for disposal through co– processing at the plant. By using these plastic waste the company expects to reduce 4 - 5 per cent of its dependence on coal for fuel. Agriculture biomass and biomass residues: India is a agriculture country. More than 60 per cent of the population depends upon agricu lture for living. These agriculture biomass and biomass residue can substitute approximately 5 - 7 per cent of fuel requirement of cement plants - rice husk, coconut shells, bamboo chips, sawdust, straw, firewood , wood flour, groundnut shell , etc . The pulp waste generated during the manufacturing of paper can also be used as an alternative to coal. Electronic waste : Discarded electronic waste is the fasters growing stream of waste in industrialized countries. Electronic wastes have multiplied due to short lifespan of electronic products. Disposing electronic waste, due to stringent laws in Europe and America, has made its way to India. Electronic gadgets can also be used in kilns for manufacturing of cement. Tyres: Tyre chips or Tyre Derived Fuel (TDF) was first used in cement kilns in the 1970s. The high temperature processing of cement manufacturing enables the use of scrap tyres as an alternative fuel sou rce. The rubber elements of tyres comprise hydrocarbon compounds which, like coal and oil, have tremendous fuel value. Tyres have 25 per cent more fuel value than coal on an equal mass basis. The Environmental Protection Agency (EPA) recognizes tire derived fuel (TDF) as an environmental best practice and encourages industries to use this resource. Using tyres for combustion in a cement kiln produces 25 per cent more energy than coal and it can also result in lower emissions. In India though the government has allowed the use of tyres, their availability is an issue. Tyres in India are reused and reused are very little is available for use in cement kilns. Importing tyres is a costly affair due to the depreciating rupee, storage space, etc. Animal waste: India has the largest population of cattle. Cow dung can be used as fuel. But the problem here is it cannot be sourced in bulk. Pet coke: Pet coke (petroleum coke) is another favourite with cement manufacturers due to its high calorific value of more than 8,000 Kcal per kg, having low ash content and low volatile matter but high sulphur content, up to 7 per cent Pet coke is a residual product of the crude oil refining process. Due to higher calorific value compared to coal , less quantity of pet coke needs to be moved from source to plant site, which reduces the cost of transport. Another big advantage of pet coke , apart from its higher calorific value, is that, being almost a waste product, it price is generally much lower than that of coal. In India, the biggest petroleum companies are located in the western part. Transporting pet coke to other parts of the country increases its cost. Sludge: Several types of sludge can be used as alternative fuels in cement kilns. These include pa int sludge, refinery (petroleum) sludge, effluent treatment plant (ETP) sludge, tar waste, etc. Sewage sludge due to its organic content can be used as an alternative fuel in the cement industry. Dried sludge has energy content comparable to brawn coal. Its 46