Syngas suitability for solid oxide fuel cells applications produced via biomass steam gasification process: Experimental and modeling analysis

The technologies and the processes for the use of biomass as an energy source are not always environmental friendly. It is worth to develop approaches aimed at a more sustainable exploitation of biomass, avoiding whenever possible direct combustion and rather pursuing fuel upgrade paths, also considering direct conversion to electricity through fuel cells. In this context, it is of particular interest the development of the biomass gasification technology for synthesis gas (i.e., syngas) production, and the utilization of the obtained gas in fuel cells systems, in order to generate energy from renewable resources. Among the different kind of fuel cells, SOFCs (solid oxide fuel cells), which can be fed with different type of fuels, seem to be also suitable for this type of gaseous fuel. In this work, the syngas composition produced by means of a continuous biomass steam gasifier (fixed bed) has been characterized. The hydrogen concentration in the syngas is around 60%. The system is equipped with a catalytic filter for syngas purification and some preliminary tests coupling the system with a SOFCs stack are shown. The data on the syngas composition and temperature profile measured during the experimental activity have been used to calibrate a 2-dimensional thermodynamic equilibrium model.

► The biomass steam gasification process has been studied in an 11 kW fixed bed reactor.
► A mixture of dolomite and MnO2 has been tested as catalyst for tar cracking.
► The syngas produced seems to be suitable for SOFC stacks (55–60% of H2).
► Some tests have been run coupling the gasifier with a SOFCs stack.
► A 2-dimensional, 2-phase thermodynamic model has been developed and calibrated.