A multiscale analysis approach for the valorization of sludge and MSW via co-incineration

The use of municipal solid waste and sludge within the waste to power initiative is evaluated following a multiscale approach. A techno-economic analysis is performed following a systematic procedure to determine the optimal operating conditions and to estimate the production and investment costs of the facilities as a function of the waste processing capacity. The facility consists of the boiler, the flue gas treatment chain, the turbine, and the cooling tower. Experimental data and first principles are used to model the boiler and the pollutant abatement technologies, while detailed thermodynamics and transport phenomena are used to model the turbine and the cooling tower to optimize the process using an equation-based approach. For the facility to produce power at a competitive price, 0.06 euro/kWh, it has to process the waste generated at cities above 250 k habitants. The investment cost is beyond 30 Meuro where gas treatment represents around 19%, with the turbine and the boiler representing 37% and 31% respectively. The rest corresponds to the cooling system. Next, at country level, a multiobjective facility location problem is formulated. From an economic point of view, only the largest cities would be selected. However, aiming at a social objective, power at a competitive price can be produced by selecting the appropriate locations for a budget available. The water - energy nexus is also evaluated for the facilities installed.