Andrea Di Carlo

Technical-Economic Analysis of an Innovative Cogenerative Small Scale Biomass Gasification Power Plant

The use of biomass waste in high efficient low pollutants emissions micro-cogeneration plants overcomes the main biomass barriers: competition with the food and material uses, dispersion of a low energy density fuel and high emissions.

Technical-Economic Analysis of an Innovative Small Scale Solar Thermal - ORC Cogenerative System

The generation of electricity from solar thermal source has continued to garner more attention due to the very attractive environmental performance, the applicability to small distributed users and as alternative to the fossil fuels power generation. Indeed, solar thermal energy, through the coupling with ORC systems, becomes fit for electric power generation as well and, with a proper thermal storage, can deliver more equivalent hours than other residential systems. The paper analyses, by means of system modelling simulation, a small solar power plant composed by a CPC heat pipe solar collector device feeding a thermal storage, an ORC and an absorber unit. Beside the analysis of configuration and design, this paper proposes an economic analysis taking into consideration the applicable incentive. The evaluation highlights the economic viability of the proposed system and tries to define a roadmap to optimize results consisting in acceptable PBT and positive NPV.

Experimental and Numerical Analysis of Steam-Oxygen Fluidized Gasifier Feeding a Combined SOFC/ORC Power Plant

The aim of this work is to experimentally and numerically analyze the performance of a combined power plant, composed by a steam oxygen fluidized bed biomass gasifier fed by woods, a Solid Oxide Fuel Cell (SOFC) and an Organic Rankine Cycle (ORC). The gasifier model is developed and validated by means of experimental activities carried out with a bench scale gasifier in our lab. Different compounds (Benzene, Toluene, Naphthalene, Phenols) were chosen to analyze the tar evolution in the gaseous stream during the gasification process. Hot gas cleaning (based on catalytic ceramic filter candles inserted in the freeboard of the gasifier - UNIQUE concept) is adopted to remove tar and particulate at high temperature from the fuel gas stream. The numerical analysis is carried out by means of the software Aspen Plus®. In particular, the SOFC and the gasifier are modelled using proper developed Fortran subroutines interfaced to the basic software. The adopted SOFC model was already validated by the authors in previous works. Finally, a realistic ORC is modelled. Different moisture contents in the range of 10–30 % (i.e. in a deviation of 10% around the usual wood moisture content of 20%) are investigated in the simulations, as also the degree of purity of the oxygen used in the power plant (between 25 and 95%, rest N2). The power requirement for the production of pure oxygen for this kind of gasification technology leads to a reduction of the electrical efficiency of the whole power plant. For this reason a sensitivity analysis was conducted to find the optimal operation conditions in order to maximise the syngas content in the produced gas (H2, CO) maintaining a high overall electrical efficiency.Copyright