Fast pyrolysis of Miscanthus sinensis in fluidized bed reactors: Characteristics of product yields and biocrude oil quality

A numerical study on biomass fast pyrolysis process: A comparison between full lumped modeling and hybrid modeling combined with CFD

“…3, the biocrude oil yield increases until 773 K and then decreases as the reaction temperature increases when the inlet gas velocity is 18.6 cm/s. This result agrees well with the experimental data (Bok et al, 2012(Bok et al, , 2013Choi et al, 2012;Ellens and Brown, 2012;Kim et al, 2014;Salehi et al, 2011;Wilson et al, 2013). For reference, CFD can resolve the complex multiphase reacting flow fields by changing pyrolysis variables however only volume-averaged temperature can be considered for the lumped model.…”

“…In addition, the maximum reaction rate of char1 decreases as the reaction temperature increases, indicating that the total amount of char1 decreases as the reaction temperature increases. This result matches well with the experimental fast pyrolysis results (Bok et al, 2012(Bok et al, , 2013Choi et al, 2012;Ellens and Brown, 2012;Kim et al, 2014;Salehi et al, 2011;Wilson et al, 2013). For the secondary reactions of NCG2 and char2, the curves of the reaction rates exhibited a similar pattern to those of the primary reaction.…”

“…14-16 present the yields of fast pyrolysis products with respect to reaction temperature for the LM, hybrid analysis and experimental data (Beis et al, 2002;Blasi, 2009;Bok, 2013;Onay and Kockar, 2004). The biocrude oil yield was calculated by taking into account the biocrude oil yield collected at the condensers and electrostatic precipitator.…”

“…Following the reaction mechanism, first, the LM of the fast pyrolysis reactor was generated. The LM was adopted for basic process simulation, although complex physical phenomena occur in the bubbling fluidized bed reactor (Bok et al, 2013). In addition, the CFD model was generated for the fast pyrolysis reactor using the same reaction mechanism.…”

“…In fast pyrolysis, the yield of the biocrude oil depends on various factors such as reaction temperature, heating rate, condensation method, residence time, biomass type, reactor type, etc. Therefore, many experimental studies have been conducted to determine the optimum conditions to obtain oil of higher yield and good quality (Bok et al, 2012(Bok et al, , 2013Choi et al, 2012;Ellens and Brown, 2012;Kim et al, 2014;Salehi et al, 2011;Wilson et al, 2013). For numerical studies, basic studies using computational fluid dynamics (hereinafter abbreviated as CFD) were carried out for the fast pyrolysis of biomass (Boateng and Mtui, 2012;Bruchmuller et al, 2012;Choi et al, 2009;Choi, 2011;Mellin et al, 2013;Papadikis et al, 2009a,b,c;Xiong et al, 2013aXiong et al, ,b, 2014Xue et al, 2011Xue et al, , 2012.…”