Multi-Objective Optimization of a Combined Power Plant Fueled by Syngas Produced in a Downdraft Gasifier

In this paper technical-economic feasibility is analyzed about a gas-steam combined-cycle, fueled by syngas produced in a local downdraft gasifier. At first, the downdraft gasifier model is briefly described, where a biomass mix of Refused-Derived Fuel, RDF, and sewage sludge is transformed into syngas; then, the economic model is introduced with the graph about the economic trends of the most important plant components. Starting from the Design of Experiment (DOE) analysis, this paper proposes a multi-objective optimization methodology to obtain the Pareto Frontier of micro gas turbine technologies. In particular, this study allowed us to determine which micro gas turbine technology is more suitable to attract investment capital. The considered performance parameters are: the nominal power of the cycle; the total plant efficiency; the net revenues; the pay back period. On the other hand, the input design variables are represented by the turbine intake temperature, the compression ratio and the biomass chemical composition.