Abstract
Purpose
Biomass gasification represents a viable alternative to improve innovative energy processes, in particular for small rural communities. This work is part of a project whose aim is the coupling of a steam biomass gasification plant with a 5kWel SOFC stack for electricity production. In particular the present paper deals with the analysis of syngas production section.
Methods
In the first part of the project the gasification system (12 kWth inlet power) has been designed and set up. The gasifier is equipped with a steam generator (evaporator and super-heater). As the stack operates at 1000-1200 K a high temperature clean up stage has been foreseen. The steam gasification process is carried out in a downdraft fixed bed gasifier. Wooden pellets have been used as feedstock for the present tests.
Results
The experimental activity has been carried out performing a series of runs varying the main gasification parameters. The average syngas molar composition shows a significant hydrogen production (63%) and a negligible presence of hydrocarbons (e.g., 1% CH4), according to the expected composition from a steam gasification process. A comparison between the measurements and the outputs of a thermodynamic model, developed during the preliminary phase of the project, is also shown.
Main conclusions
The experimental composition confirms that steam gasification represents an interesting pathway for the biomass utilization, because it leads to high quality effluent gas. The proposed equilibrium model seems to be a useful engineering tool, as the measurements syngas composition is not so far from the thermodynamic predictions.