Investigating the behavior of six limestones in presence of steam in dual interconnected fluidized beds, under operating conditions relevant for sorption-enhanced gasification

This paper presents results on the behavior, in terms of CO2 capture capacity and attrition/fragmentation tendency, for six limestones processed in a dual interconnected fluidized beds system under operating conditions simulating those of sorption-enhanced gasification in presence of water vapor. Ten calcination/carbonation cycles have been carried out for each sorbent; in particular, carbonation has been carried out at two temperature levels (650 °C and 700 °C), with a CO2 and H2O inlet concentration of 10% for both gases. Degree of CaO carbonation (with related modelling) along the cycles, and particle size distribution at the end of the cycles, have been analyzed and discussed, together with results coming from ex situ impact fragmentation tests carried out in a specifically devoted apparatus. The discussion has been extended to particular cases in which the system was operated in the absence of steam, to analyze the role of this species on the sorbent behavior.