Impact of biomass char on coal char burn-out under air and oxy-fuel conditions

Impact of CO2 on biomass pyrolysis, nitrogen partitioning, and char combustion in a drop tube furnace

“…The difference in crystalline structure exhibited by sawdust and pinewood under CO 2 and N 2 could arise from the variable concentrations of alkali and alkaline metals present in the parent samples. In a previous study, it was observed that the concentrations of alkali and alkaline earth metals was much higher in the ash of the pinewood sample than those in the ash of the sawdust sample [24]. López et al [25] investigated the pyrolysis of four different types of biomass samples in N 2 and observed that the chars produced from oaks had a marked crystalline nature due to CaCO 3 formation while chars derived from silver fir and stone fir did not contain CaCO 3 .…”

OxyCAP UK: Oxyfuel Combustion - academic Programme for the UK

“…However, when devolatilisation occurred in CO 2 or CO 2 /steam, the higher yields of volatiles led to significantly higher proportions of fuel nitrogen being released; The impact of CO 2 on char burnout varied significantly with different coals; and Biomass co-firing can improve char combustion performance in both air and oxy-fuel firing conditions, and the effect is significantly more pronounced in oxy-combustion [6].…”

Study on Catalytic Combustion of Biomass Mixtures with Poor Coals

“…Therefore, catalyst loading for the most active oxides of iron and calcium was selected to be 10% wt for subsequent tests, taking also in consideration that for this catalyst quantity the ignition temperature of Mavropigi lignite was closer to that of the biomass materials under study. In addition, iron and calcium oxides are not expected to contribute to operational problems in boilers, such as slagging, fouling, or corrosion (Farrow et al, 2013;Vamvuka and Kakaras, 2011).…”

“…Alkali, alkaline earth, and transition metals in the form of salts or oxides have demonstrated higher combustion performance by decreasing ignition temperature and increasing combustion rates (Gong et al, 2010;Le Manquais et al, 2011;Wu et al, 1998). The catalytic effect is considered to arise from the improved oxygen transfer behavior, which is caused by the oxygen storage and redox properties of the metal oxides and the first ionization energy of the metal in the case of salts, during the combustion process (Farrow et al, 2013;Gong et al, 2010;Wu et al, 1998).…”

“…Therefore, the aim of this work was to investigate the ignition and combustion characteristics of different biomass materials, typical of South European countries, and one lignite (as an indigenous fuel of Greece, it is very important for the national economy), as well as mixtures of them in the presence of catalysts. The thermogravimetric analysis technique has been used, as it has been proved (Farrow et al, 2013;Shen and Qinlei, 2006;Wang et al, 2011;Zhaosheng et al, 2009) as a valuable method for obtaining detailed information about reaction rates, burning time, and temperatures and any interactions between individual blend constituents. The results should be useful for further design and operation of co-firing units, and may provide important information for promotion of biomass materials as co-fuels for energy generation.…”