Biomass energy conversion is a reliable way to produce energy and chemical products if compared with other renewable sources such as wind, solar and wave which have intermittent nature. Amongst different methods of converting biomass to energy, the thermo-chemical process of steam gasification is an outstanding way, since it enables a subsequent polygeneration process that can lead to production of heat, electricity, synthetic natural gas and synthetic chemicals such as methanol, Fischer-Tropsch diesel, gasoline and kerosene. The modelling of biomass gasification enables the optimization of the process designs, but it is a challenge due to its high complexity. Here, a new approach is used to simulate a 100 kW dual fluidized bed gasifier. Detailed pyrolysis modelling is a key factor of this approach and enables more accurate results. The results have been validated by experiments conducted with softwood pellets as fuel and fresh olivine sand as bed material. The impact of the gasifier temperature variation on the final product gas composition is measured in the experiments and implemented in the simulation to have a better insight on the pyrolysis process, the char heterogeneous reactions as well as the deviation from equilibrium of the water gas-shift reaction.
An analysis of different floating platform concepts in site conditions typical of the Mediterranean Sea is presented. A tension leg platform, a spar buoy, and a barge support substructures were investigated. In all the three cases, the National Renewable Energy Laboratory 5-MW machine was considered as wind turbine. This turbine model was also used to carry out a performance comparison between the selected offshore site and an adjacent onshore site, in order to estimate the advantages of the offshore solution in terms of annual energy production. The comparison among the different floating platform concepts considers the loads on the turbine induced by different wind and wave conditions. The simulations were performed using the fully coupled time domain aero-hydroservo-elastic simulation tool FAST, made available by National Renewable Energy Laboratory. The wind and waves data used in the simulation, provided by the UTMEA-CLIM laboratory of ENEA, are typical for Mediterranean Sea conditions. The simulation results are reported and discussed. They represent a first contribution in helping to resolve basic design trade-offs among different floating platform concepts candidate for offshore wind energy deployment in Mediterranean Sea.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.