Cement and Energy

It is seen that 30% of plants are operating in the range of 105 to 115 kWh/tonne cement and majority of plants (43%) are operating in the range of 95 to 105 kWh/tonne, while only 13% plants have achieved the target of operating below 95 kWh/tonne cement. Section-wise power consumption during 1995-96 is shown in Table 1. NCB took the initiative in modernising the techniques for energy audit. NCB 's Mobile Energy Diagnostic Unit (Energy Bus) is equipped with latest and sophisticated facilities for faster and accurate energy audit studies with various hardware and software capabilities. NCB has so far carried out 96 energy audit studies including Table 1: Section-wise specific power consumption (kWh/tonne material) 24 through the Mobile Energy Diagnostic Unit and has helped identify the plants, their individuals potentials for energy and cost saving. Reduction in the consumption of thermal energy up to 164 kcal/kg clinker and electrical energy upto 16.4 kWh/t cement was found possible in some cases. The total annual savings potential identified by NCB in the 24 plants studied with Energy Bus amounted to 0.22 mil.t. coal and 88.50 million e lectrical units equivalent to about Rs.366 million (US $ 10.5m) . Sl. Section Dry Process Wet Process No. Range Average Range I Crusher 1.09 - 4.07 1.91 2.06 - 3.50 2 Raw grinding : a) Ball mill 17.79 - 28.40 23.03 12.20 - 20.79 b) VRM 14.02 - 24.50 18.61 - 3 !Gin section 25.16 - 44.20 30.17 16.78 - 26.00 4 Coal grinding: a) Ball mill 25.50 - 67.23 41.00 29.09 - 35.90 b) VRM 18.90 - 35.50 28.32 - 5 Cement grinding 28.17 -52.23 34.00 32.00 - 47.61 6 Packing 0.94 - 3.38 1.96 0.80 - 1.52 NCB's initiatives for energy conservation NCB has taken initiatives towards developing an integrated approach for assisting the industry in energy conservation through techn?logical support and R&D. These aspects are highlighted below : Energy audit Energy audit has emerged a potent tool for identification, analysis and implementation of energy conservation measures and overall energy management. The importance of energy audit studies was realised in the 1980' s when NCB along with the Bureau of Industrial Costs and Prices made a survey of 46 cement plants in the country for identifying the status of energy consumption levels, potential areas for energy saving and formulating specific recommendations. Subsequently, Average 2.28 17.21 - 21.88 32.47 - 38.01 1.32 Monitoring and target setting for energy Having emphasised the need for monitoring energy use, NCB has brought out guide norms for cement plant operations which also provide norms for energy use in the various sections of the plant. The norms have been in use in cement plants extensively for evaluating the performance of a given section and identifying the areas of improvement. The energy monitoring study of NCB's Mobile Energy Diagnostic Unit (Energy Bus) 6