Cement, Energy and Environment

The absence of necessary infrastructure to support co-processing is one of the main reasons of its slow growth in India. There is thus, an urgent need for stakeholders to come together and evolve a national strategy and a time bound programme for building up the infrastructure, writes S P Deola/kar. The Indian cement industry, Number Two in . outsourcing of this activity which is a new feature. the world, is modern technology-wise, and efficient Creating such supporting facilities means creating in terms of energy consumption. It is consciously infrastructure. An appropriate example of an taking steps to bring down C02 emissions. As a infrastructure created to meet the needs of the part of this effort, India has taken up co-processing society is 'AMUL'. of Alternate Fuels (AF) but the overall rate of substitution is very low, just about one per cent. infrastructure to support co processing is the main reason of its slow growth in India. Volume of AFs required Installed capacity for and actual production of cement in India is 330 and 250 mtpa respectively. About 75 per cent cements produced are blended cements. With a clinker/cement ratio of - 0.72, clinker production would be - 180 mtpa requiring 38 - 40 mtpa of raw coal. If only ten per cent of it is replaced by AF, requirement of AF would be say 3.5 - 4 mtpa. Thus, there is tremendous scope for development of AFs as a viable industry in itself. Various aspects of co-processing AFs have been brought out in the author's book 'Designing Green Cement Plants. Need for infrastructure The simple reason for the need for infrastructure is to create an environment where wastes with potential as fuels (AFs) would be continuously available to cement companies preferably in ready to use form. Incidentally, using coal also requires infrastructure and processing to be able to fire it in kilns and calciners. Historically, cement companies have taken on themselves this responsibility. In contrast to coal , AFs come from a vast number of sources, are spread over a wide territory and differ greatly in properties and availability. Identified as wastes till now, it is necessary to begin at the beginning when planning to convert them into fuels and using them. Processing required to be done varies greatly from one type of AF to the other. Co-processing replaces fossil fuel by say, a maximum 40 per cent. A cement plant is therefore required to process two types of fuels- sometimes three - if it is required to use two types of AFs as their continuous avai lability is not assured as of now. Hence investments in machinery and buildings for processing AFs are considered ri sky. For these reasons, cement companies would prefer buying the AF that can be del ivered on their doorstep in ready to use form. This tn turn implies Infrastructure required for AFs The concept of using wastes on a large scale itself being new. there is not much information on their properties. sources and locations. Infrastructure would therefore comprise of: • Compilation of data in the form of a directory of wastes and potential AFs among them. • • Testing the more promising among them for determining various aspects of burning them as fuels. Pilot plant tests on the selected AFs . Setting up agencies which would do handling and processing of AFs and would supply them on a commercial scale to cement (or any other) industry continuously. Directory of wastes and their potential The first step in the build-up of infrastructure would be to collect categorical data on wastes that could be AFs. Such data would classify wastes and other non conventional sources of fuel according to their properties, heat value, sources , locations, avai labil ity and volume/ quantity. Such data supplemented by maps showing locations would be very useful to potential users. Refer to the map which is similar to maps of Geological Survey of India for mineral wealth of the country. Often this is the starting point for location of a green field cement plant. Such data should be collected on a national level and should be available for all industries and for uses other than burning also. Research on wastes as fuels The next step on a national scale would be to have a fuel research institute that would carry out detailed research on every aspect of combustion of likely AFs such as products of combustion, gases emitted and ashes produced. In making cement, ashes enter clinker produced. Some wastes give away harmful compounds like NOx . dioxins, heavy metals. It is important to know about them before beginning to use them on a targe scale. The Central Fuel Research Institute can be one such institute and should play an 25