Three-dimensional CFD simulation of co-gasification of biomass and plastic wastes (SRF) in a bubbling fluidized bed with detailed kinetic chemical model

In this study, a three-dimensional computational fluid dynamics (CFD) model using multiphase particle-in-cell (MP-PIC) method with large eddy simulation (LES) was developed to investigate the characteristics of the co-gasification of densified wood pellets (WP) and rice husk pellets (RHP) with SRF in a bubbling fluidized bed reactor. ER reduction from 0.30 to 0.10 resulted in a decrease in specific gas yield per total feed from 1.20 g/g_total to 0.96 g/g_total and from 1.20 g/g_total to 0.67 g/g_total during SRF/WP and SRF/RHP co-gasification, respectively. Reducing ER during SRF/WP co-gasification allows to increase C₂–C₃ HCs yield reaching 0.33 g/g_srf (0.15 g/g_total) at ER = 0.15, 0.556 kg/h SRF, and 0.693 kg/h WP. Carbon conversion efficiency (CCE) and cold gas efficiency (CGE) at the same conditions reduced to 83% and 74%, respectively. Co-gasification of 0.667 kg/h SRF and 2.040 kg/h RHP allowed to reach 0.28 g/g_srf (0.07 g/g_total) C₂–C₃ HCs yield, but drastically reducing CCE and CGE to 71% and 46%, respectively. SRF/WP co-gasification is suggested for low cost C₂–C₃ HCs recovery from SRF with coproduction of syngas retaining 48% to 57% of initial LHV, meaning that SRF/RHP co-gasification is more suitable for syngas production.