Sustainability is one of the main goals to achieve in order to guarantee a future for future generations and requires, among other issues, the recourse to renewable energy sources and the minimization of waste production. These two issues are contemporarily achieved when converting waste and residual biomass into energy. This paper presents an innovative concept for energy conversion of the abovementioned residual fuels; it combines a rotary-kiln pyrolyser, where the residual energy sources are converted into a medium lower heating value (LHV) syngas, with a gas turbine that produces energy, and also provides waste heat to maintain the endothermic pyrolysis reaction. Byproducts of the reaction include char and tars that have an interesting energetic content and may also be used to provide supplementary heat to the process. Through software modelling the paper analyses the influence on performance of main thermodynamic parameters, showing the possibilities of reaching an optimum for different working conditions that are characteristic of different sizes of gas turbines. This is interesting both for medium-to-big size power plants, where the IPRP efficiency is comparable to a grate-based incinerator, but at lower investment costs, and in the micro-small scale, for which there is no available technology on the market.