During biomass or waste gasification, limestone-based sorbents can be used to in-situ remove CO2 from syngas to shift the equilibrium of the water gas shift reaction (CO + H2O = CO2 + H2) towards a higher hydrogen production. This concept, resulting in the so-called Sorption-Enhanced Gasification (SEG) process, is favourably applied in Dual Interconnected Fluidized Beds (DIFB) where the Ca-based sorbent is continuously cycled between the gasifier, where CaO captures CO2, and the combustor, where CaCO3 gives, via calcination, CaO and a CO2-enriched flue gas. In this work, the CO2 capture capacity and the attrition/fragmentation tendency of six European limestones were investigated in a batch lab-scale interconnected fluidized bed system under simulated sorption-enhanced gasification conditions. Two carbonation temperatures (650°C and 700°C) were investigated, by carrying out ten calcination/carbonation cycles for each limestone, with 10% inlet CO2 and H2O. The role of steam, not accounted for in previous works, was therefore analyzed. When considering the CO2 capture capacity, no monotonic trend with the temperature in the presence of steam can be observed, due to the combined effect of kinetics and diffusion enhancement as opposed to sintering and thermodynamic limitations. As for the mechanical performances, steam-induced sintering is enhanced at the highest carbonation temperature, resulting in more resistant particles with lower fragmentation indexes. However, when comparing the results of the present study with tests carried out under dry conditions, at a fixed carbonation temperature, H2O seems to increase particle fragilization.