Numerical simulations for the coal/oxidant distribution effects between two-stages for multi opposite burners (MOB) gasifier

Numerical simulation of lignocellulosic biomass gasification in concentric tube entrained flow gasifier through computational fluid dynamics

“…The maximum temperature observed for the CS, RH, SB, and SD at 1.1 O/F ratios, was 2611.79 K, 2662.67 K, 2689.67 K, and 2569.27 K, respectively. Temperature contours obtained in this research are in similar ranges as per findings of previous researchers (Chen et al., 2013; Gao et al., 2016; Unar et al., 2014). The maximum temperatures of entrained flow gasifier usually come in the range of 1300–1500°C but in those cases, the walls of the entrained flow gasifiers are assumed to be cooled (usually via cool water).…”

“…In simulations, this is usually performed by fixing the gasifier wall temperature at lower temperature levels. But several authors (Chen et al., 2013; Gao et al., 2016; Unar et al., 2014), performed simulations using entrained flow gasifiers and achieved temperatures above 2000 K. So these high temperatures seem normal. The maximum temperature was observed in SB, and the probable cause of this increased temperature is its highest heating value (17.33 MJ/kg) and higher amount of H (5.96) available in its ultimate analysis (Table 4).…”

“…The gas species such as CO and H 2 produced through reactions (equation (17)), (equation (18)), and (equation (21)) in gasification section and were released from the outlet. The oxidation reactions were observed in the gasifier’s combustion zone (Unar et al., 2014). In the highest temperature zone of the gasifier, the CO 2 mass fraction achieved its highest levels.…”

“…The injector design with concentric-tubes plays a vital role in the proper mixing of fuel particles with an oxidizing agent at near entrance (Unar et al., 2014). It can be observed in Figure 9, in which flow streamlines are shown and indicating a vertical vortex at the entrance plane.…”

“…Entrained flow gasifiers (EFG) are widely used because of short residence time and high carbon conversion efficiencies (Zheng and Furinsky, 2005). Entrained-flow gasifiers having opposite multi burners (OMB) provide greater collision rates between solid particles and better fuel conversion efficiencies (Li et al., 2012; Ni et al., 2009; Unar et al., 2014). Presently concentric tube entrained flow gasifiers (CT-EFG) are focused by researchers and considered good in performance due to the vigorous mixing of feedstock and an oxidizing agent.…”