doi:10.1016/j.energy.2023.128559engDíez, Luis I.García-Mariaca, AlexanderCanalís, PaulaLlera, EvaOxy-combustion characteristics of torrefied biomass and blends under O2/N2, O2/CO2 and O2/CO2/H2O atmospheresART-2023-135262The combined use of bio-fuels along with CO2 capture techniques is the basis for the so-called negative emissions energy systems. In this paper, oxy-fuel combustion of two torrefied biomasses is experimentally investigated in a lab-scale entrained flow reactor. The torrefied biomasses are fired alone, and co-fired with coal (50%). Two oxygen concentrations (21% and 35%) and four steam concentrations are tested: 0% (dry recycle oxy-combustion), 10% (wet recycle oxy-combustion), 25% and 40% (towards the concept of oxy-steam combustion). The tests are designed to get the same mean residence time for all the fuels and conditions. Burnout degrees are significantly increased (up to 9 and 16 percentage points) when the share of torrefied biomass is raised, with a slightly better behavior of the torrefied pine in comparison to the torrefied agro-biomass. C-fuel conversion to CO2 follows a similar trend to the observed for the burnout degrees. NO formation rates are reduced when oxy-firing torrefied biomass alone in comparison to the blends, with maximum diminutions of 16.9% (torrefied pine) and 8.5% (torrefied agro-biomass). As regards the effect of steam, the best results are found for the 25% H2O atmospheres in most of the cases, yielding maximum conversions along with minimum NO levels.2023http://zaguan.unizar.es/record/12810210.1016/j.energy.2023.128559http://zaguan.unizar.es/record/128102oai:zaguan.unizar.es:128102info:eu-repo/grantAgreement/ES/MICINN/RTI2018-094488Energy 284 (2023), 128559 [11 pp.]by-nc-ndhttp://creativecommons.org/licenses/by-nc-nd/3.0/es/info:eu-repo/semantics/openAccess