The Effect of Air Flow Rate and Biomass Type on the Performance of an Updraft Biomass Gasifier

Abstract

Airflow and the type of biomass are the two most important factors influencing the performance of a biomass gasifier. In this research, the effects of air flow rate (air-fuel equivalence ratios of 0.21, 0.25, and 0.29) and biomass type (woody biomass, agricultural residue, and perennial grass) on the performance of an updraft biomass gasifier were evaluated based on its tar and producer gas generation. It was found that increasing airflow increased the formation of tar species for all biomass types studied, but no significant differences in producer gas composition were found when the air-fuel equivalence ratio was changed. Thus, air-fuel equivalence ratios ranging from 0.21 to 0.25 were deemed appropriate for minimal tar generation. The results also showed that different biomass types generated producer gas with significantly different tar contents: woodchips yielded the most tar, followed by sorghum stover and prairie hay. The higher heating value of producer gas from various biomass types was also significantly different. Wood chip-derived producer gas had the greatest higher heating value, followed by prairie hay and sorghum stover. The carbon monoxide content in the produce gas of the three biomass types also exhibited significant differences with varying biomass type, similar to the higher heating value, but there were no significant differences in the H2 content with varying biomass type or airflow.

Characterization of Recycled Wood Chips, Syngas Yield, and Tar Formation in an Industrial Updraft Gasifier

“…Results pertinent to syngas composition indicate that the variation of CO as a syngas component with fuel moisture content is in line with studies performed by other researchers [8,[19][20][21]23]. Specifically, as fuel MC increases from 20% to 35%, CO concentration has a pronounced drop and this leads to a reduction in the syngas HHV.…”

“…The H 2 content was found to have no significant changes while the CO content was somewhat reduced as the moisture content increased from 10% to 22% wb, resulting in a decrease in the higher heating value of the syngas from 3.67 to 2.84 MJ/m 3 . In a related study, James et al [23] found that as ER increased from 0.21 to 0.29, tar formation was raised from 1.6 to 3.1 g/m 3 for all types of biomass in their experiment, but there was no influence on syngas composition.…”

Effects of wood biomass type and airflow rate on fuel and soil amendment properties of biochar produced in a top‐lit updraft gasifier

“…In this study, the mass yield of biochar for all biomasses was between 8% and 11%. These results are similar to those presented by James et al [44] who used a TLUD reactor at the laboratory scale and with the airflow rate of 20 L/min.…”

“…These results are similar to those presented by James et al . who used a TLUD reactor at the laboratory scale and with the airflow rate of 20 L/min.…”

The Effect of Biomass Physical Properties on Top-Lit Updraft Gasification of Woodchips

“…The second stage was composed of two additional flasks submerged in dry ice (approximately´79˝C) at which most of the remaining tars was condensed. A similar method for tar collection was previously implemented [11,34,35]. A vacuum pump (Cole-Parmer, L-79200-30, Monroe, LA, USA) was used to flow the syngas within the tar sampling system, and a gas flow meter (Omega, PMR1-014697, Stanford, CT, USA) controlled the sampling rate at 10 lpm.…”