Cement Energy and Environment

of burner position, leads to premature failure of refractory bricks. Maintaining a consistent raw mix becomes a challenge to the quality control department. • Presence of Sulphur increases chances of dusty clinker formation which leads to poor heat recuperation from secondary air to flame and reduces flame temperature with subsequent increase in heat consumption. • Installation of modern multi-channel, high momentum burner can improve the burning zone condition with more uniform RDF feeding and firing arrangement and consistent fuel quality by better pre-processing techniques. • To reduce the exit gas volume periodic maintenance of the dynamic parts of the preheater to limit false air ingress becomes more important along with the maintenance of kiln inlet & outlet seals. • Process monitoring and quicker response time to the changes in set point paramett~rs are the requirement for consistent feed rate & desired burning zone conditions. • Installation of Oxygen enrichment technology can be foreseen to improve flame temperature, which shall reduce exit gas volume due to reduced heat consumption. • Challenges in the utilization of RDF for Clinker manufacturing are due to its low and inconsistent heat value (-1100 to 2500 kcal/ kg); high moisture content (-20 - 25%) , ash (-25%), sulphur (<1%) & chloride (<1%) content and their coarse granulometry. However, due to its low cost it still mmains an attractive solution to replace fossil fuel, provided it is supplied to the cost without considering transportation charges. Policy constraints • The main barrier in RDF usage in Indian Cement Industry is the absence of unified waste management system for identification, treatment & conti nuous supply of waste to cement plants. • Absence of clear policy, to encourage conversion of MSW to RDF and its co– processing in Cement plants and lack of coherent & detailed information regarding the availability of MSW in public domain, act as deterrents for increasing the use of RDF in cement kilns. • Absence of efficient segregation mechanism for components having high heat value & recyclable waste leads to the reduction & inconsistency in calorific value and hence, overall reduction in Thermal substitution rate (%TSR). • Elimination of inappropriate practice of burning combustible-household/ factory waste in open air, will help in conserving our fossil fuels with reduction in carbon foot print and RDF co– processing should be taken as CSR activity, leading to unlocking the finances for societal benefits besides solving the menace of MSW. • Incentives to cement plants in terms of land, financial subsidies for collection of waste & pre-processing & transportation to plant • Right to use of waste by cement plants within a radius of 100 km from source of generation without financial implications • Easing of inter-state movement of waste with minimum restrictions. • Relaxation of permissible emission norms for cement kilns using co-processing. • Increasing availability of hazardous waste for co-processing by including part of hazardous wastes , presently used for land filling, based on their calorific value. • Prequalification criteria should be set for cement plants utilizing RDF, considering environmental safety & cement quality parameters. It should include technical assessment of RDF, Quality control laboratory, continuous monitoring system, appropriate RDF pre-processing & feeding system etc. • Taxation on landfill of MSW will help in increasing co-processing of MSW. Polluter Pays' principle Waste generators to pay for collection, pre processing and transportation from source till cement plant gate. A statutory law in this matter needs to be formulated in the form of collection of a certain cess from the polluter. Financial barriers Use of RDF on account of high investment cost for the installation of pre-processing units besides high cost of transportation of RDF and high cost of collection of MSW. Due to long lead distance between the cement plants and the MSW source the cost of logistics also increases, making RDF consumption economically unattractive. Developing a proposal to bring together all the necessary stakeholders to a meaningful coalition shall increase the RDF consumption in Indian cement industry. 18 ..