Measurement of reaction rates for pulverized fuel combustion in air and oxyfuel atmosphere using a novel fluidized bed reactor setup

Investigation of the apparent kinetics of air and oxy-fuel biomass combustion in a spout fluidised-bed reactor

“…The kinetics study of solid fuels is conducted in a range of equipment, including: the thermogravimetric analyser (TGA) (Liu, 2009;Wang et al, 2015), drop-tube reactor (DTR) (Tolvanen et al, 2016;Tolvanen and Raiko, 2014), entrained-flow reactor (EFR) (Álvarez et al, 2011), wire-mesh reactor (WMR) (Kim et al, 2017), and fluidised-bed reactors (FBR) (Fennell et al, 2009(Fennell et al, , 2007(Fennell et al, , 2005Gövert et al, 2017).…”

“…TGA kinetic analysis allows direct measurement of sample mass, with high repeatability. However, the low heating rates and the effects of the heat and mass transfer influence the accuracy of the experimental results and are generally regarded as problematic when determining intrinsic kinetic parameters (Gövert et al, 2017;Kim et al, 2017). EFR and WMR by contrast, have complicated measurement and analysis and require a skilled operator which limits their application (Fennell et al, 2009).…”

“…EFR and WMR by contrast, have complicated measurement and analysis and require a skilled operator which limits their application (Fennell et al, 2009). Aside from these techniques, other researchers (Fennell et al, 2009;Gövert et al, 2017) have proposed using a bench-scale fluidised-bed reactor (FBR) with a fast-response gas analyser to investigate the kinetics of char combustion. This method can provide homogeneous temperature and bulk gas composition, high heating rates (around 10 4 K/s), sufficient residence time, flexible temperature and gas compositions and an approximate carbon mass balance (Kim et al, 2017;Li et al, 2015;Mueller et al, 2015).…”

“…Similarly, Gövert et al measured and compared the kinetic parameters of coal char combustion and gasification under air/oxy-fuel combustion using the same reactor and noted that the reaction of char in air was faster than in oxy-fuel atmosphere, and that there is no significant difference in activation energies in air and oxy-fuel combustion (Gövert et al, 2017). Generally, it has been found that the results obtained through FBRs can be comparable those obtained from EFRs and TGAs, once the minimisation of mixing effects and fast analysers are employed (Fennell et al, 2009;Gövert et al, 2017;Mueller et al, 2015).…”

“…Compared with the existing kinetic studies of coal char combustion for FBR, there is a dearth of literature regarding air and oxy-fuel combustion of biomass when employing a FBR. Much of the previous work has focused on the kinetically-controlled oxidation reaction of char in different oxidising gases (Fennell et al, 2009;Gövert et al, 2017;Haustein et al, 2015;Morin et al, 2018). The apparent kinetics of air and oxy-fuel combustion of raw biomass by the FBR method and the effects of devolatilisation and volatile matter combustion on the kinetics measurement of char have not been well investigated.…”