Energy efficiency aspects of urban waste recovery

Today, the waste represents one of the most serious issues of the environment protection. Annually big amount of waste is generated. Economic operators can exploit various types of waste, which may be treated, recycled or can be routed to a treatment plant (for reducing degree of nuisance) or to an incinerator (for reducing the volume). Unused waste is, as a general rule, stored. In this case study, the municipal wastes are analyzed as secondary energy resources of chemical nature, characterized by a lower heating value. Direct burning (thermo-destruction) of the solid municipal waste is an oxidation process of high temperature which transforms the waste combustion part into carbonic anhydride and water vapours. The recovery of municipal waste was performed in an energetic way inside an energetic boiler in order to obtain a thermal agent in two situations of analysis: — the thermal agent is hot water; — the thermal agent is steam. The thermal energy which results from this process is utilized in the incineration plant in order to assure the internal thermal needs. In both of the analysed situations the recovery is energetically efficient as primary fuel was economized and a high recovery degree was registered.