The present paper focuses on the gasification of thin wood particles in pure CO2 at 850 degrees C under high heating rate conditions (similar to fluidized bed gasifiers). The aim is to assess the potential use of CO2 as gasifying medium and to learn more about its effects on the pyrolysis as well as on the char gasification stages. Experimental and numerical modelling results provide answers on the unfolding of the whole CO2 biomass pyro-gasification process. It was found that despite the CO2 is present inside the particle during the pyrolysis stage, it has no noticeable impacts neither on the reaction rate nor on the char yield due to the relatively low temperature inside the particle. The CO2 char gasification is the rate limiting step of the global pyro-gasification reaction as its duration is near to 95% of the entire biomass conversion time. (C) 2015 Elsevier Ltd. All rights reserved.