High efficiency orc for high temperature molten salt boiler for biomass applications

INTRODUCTION Efficient and sustainable production of energy from biomass is one of the key factors in achieving the objectives set out in the Climate and Energy package of the European Commission. In the last decade, European and national research programs have focused both on local planning of biomass-to-energy pathways and on the improvement of the overall efficiency of energy conversion. Biomass-fired small-scale CHP systems can play an important role for the distributed cogeneration and the sustainable usage of local resources, but research is still required to improve the overall efficiency and reduce emissions. The state of the art for wood-fired CHP plants up to 3 MWe is represented by Organic Rankine Cycle (ORC) (Turboden, 2013; Obenberger and Thek, 2008, Dong et al., 2009). It is a consolidated and reliable technology that offers many advantages: relatively high efficiency, simple start up procedures, simple O&M and proven long life (greater than 20 years) (Quoilin and Lemort, 2009; Tchance et al., 2011). This work aims to present an innovative cogenerative Organic Rankine Cycle operating with fluids at high temperature (up to 400°C), coupled with a biomass-fired molten salts boiler, that allow to obtain an electrical efficiency over the threshold of 20%.