Effect of Variation in the Chemical Constituents of Wastes on the Co-processing Performance of the Cement Kilns

Cement kiln co-processing is a globally practiced technology for management of different kinds of wastes in an environmentally sound and ecologically sustaining manner. Different types of wastes e.g. agro-wastes, hazardous & non-hazardous industrial wastes, combustible fractions from MSW etc are disposed off in large quantities in many cement kilns in different countries all over the world. During the treatment of wastes through co-processing, wastes get utilised as Alternative Fuels and Raw materials (AFRs) in the cement kilns. In India, cement plants have initiated co-processing of wastes and to prove the acceptability of cement kilns for their environmentally sound disposal, cement plants have implemented large number of demonstration trials on different kinds of waste streams as per the protocol prescribed by Central Pollution Control Board. Based on the critical evaluation of the results of these trials, Central Pollution Control Board endorses the acceptability for their co-processing in cement kilns. In this paper, results of such 22 demonstration co-processing trials – which were endorsed as successful by CPCB - are evaluated to understand the extent of variation present in the chemical constituents of these waste streams. It was also concluded through this evaluation that different waste streams having large variation in the chemical characteristics can be managed in an environmentally sound manner in the cement kilns.