PRODUCT DISTRIBUTION AND HEAT FOR PYROLYSIS OF DRY SEWAGE SLUDGE

Although pyrolysis of sewage sludge is an emerging alternative for managing this residue, the use of autogenous atmospheres has been seldom investigated, nor has been the experimental determination of the heat involved in the process. Performing pyrolysis under a self-generated atmosphere allows to reduce the energy consumption. The fact that the gas surrounding the solid is composed of the vapours produced during the pyrolysis itself could have effect on the products distribution. Different approaches have been developed to assess the heat involved in pyrolysis with high disparity in the results. Knowledge of the heat requirements is necessary for the design of pyrolysis systems, especially for heat integration and temperature control. The aim of the present study is to study the effect of the autogenous atmosphere on the sewage sludge pyrolysis products and to estimate the heat required for pyrolysis.