Syngas is a promising low-carbon gaseous fuel for auxiliary electricity power generation through flexible compression ignition dual-fuel IC engines. But as syngas compositions are linked to the biomass source and the different production processes, this work has as first objective to provide fundamental data, I.e. laminar flame speed, for different syngas compositions in decane/syngas mixtures as a function of initial thermodynamic conditions, with decane as the reactive fuel surrogate. Then, some initial combustion performance results, in dual-fuel operation, are presented and analyzed as a function of diesel type fuel quantity in the main syngas charge. In future work, optical experiments will be done to contribute to the understanding of the combustion process.