Cement, Energy and Environment

ABSTRACT The cement industry is reckoned the most energy consumed industry in terms of consump on. The energy cost forms about 35 to 45 % of the total cost of produc on. Out of this, thermal energy cons tutes around 70 %, where as electrical energy about 30 %, which may vary from plant to plant. Owing to this, efficient energy u liza on has always been a focus point in the cement industry. If we improve energy efficiency, we may be able to reduce the cost of produc on of cement. In the product like cement, which is primarily a low value product, with high incidence of taxes and du es, high energy costs, the avenues available to a plant for reducing the costs are limited. In the present environment due to the energy crisis and steep increase in the cost of energy and other input materials, it has become impera ve to give a serious thought on how to make opera ons and equipment efficient towards use of energy and adop on of latest technology equipments to retain the requisite compe ve edge in the market. INTRODUCTION India was the second-largest cement producer in the world in terms of cement capacity during 2018. The industrial sector accounts to 30-70% of the total global energy consump on of which cement industry is one of most energy intensive industries in the world. Energy consump on by a cement industry is es mated at about 2% of the global primary energy consump on (or) which is almost 5% of total global industrial energy consump on. Cement produc on, which is highly dependent on the availability of natural resources, will face severe scarcity of resources in the future. Cement manufacturing has regarded as an intensive consumer of natural raw materials, fossil fuels, energy and is a major source of mul ple pollutants. Because of the dominant use of carbon-intensive fuels such as coal, the cement industry is also a major source of carbon dioxide. The cement industry contributes 5% of total carbon dioxide emissions. For clinker produc on, a cement industry requires the substan al energy consump on. About 70% of energy consump on lies on the unit of rotary kiln system. The higher amount of energy consump on is due to the lack of work efficiencies tools leading to the wastage of heat. It is found that about 40% of the total input energy was lost through kiln shell, cooler stacks and hot flue gas. Therefore, it is important to pay a en on to reduce energy consump on by reducing 'THERMAL LOSSES' and energy related environmental emissions in both local and global scales. THERMAL LOSSES = LOSSES DUE TO RADIATION+ LOSSES DUE TO CONVECTION WHAT IS RADIATION Radia on is transfer of heat through electromagne c waves through space. Unlike convec on or conduc on, where energy from gases, liquids, and solids is transferred by the molecules with or without their physical movement, radia on does not need any medium (molecules or atoms). Energy can be transferred by radia on even in a vacuum. Example, sunlight travels to the earth through space, where there are no gases, solids, or liquids. Heat transfer through radia on takes place in form of electromagne c waves mainly in the infrared region. Radia on emi ed by a body is a 1 K K Sharma INVOTECH SOLUTIONS & SYSTEMS ENERGY SAVINGS BY REDUCTION OF THERMAL LOSSES FROM KILN SHELL 39