New annular steam-biomass reactor design for hydrogen-enriched producer gas production.

Biomass conversion using air gasification suffers from the high N 2 gas dilution. Using steam as gasifying agent eliminates this issue, but heat must be supplied efficiently using external sources. This study investigated biomass steam gasification in a new annular reactor design with a gas heating jacket. This experimental study used two steam injection configurations: bottom and top to evaluate the effect of gasification temperature and steam to biomass (S/B) ratio on H 2 % using wood pellets. Temperature varied in the range of 300–600 °C for bottom injector, while S/B varied from 1.7 to 2.6. Peak H 2 % was 27.7% and higher heating value (HHV) of gas was 7 MJ/Nm3. Using top injector enhanced the heat transfer which elevated the temperature range (700–950 °C) and reduced S/B ratio in the range of 1.3–2.2, achieving H 2 % of 44% at the optimum steam flow rate of 30 g/min with HHV of 12.7 MJ/Nm3. Tar contamination was reduced from 13.6 g/m3 to 7.4 g/m3 with the increase of S/B. The effect of different fuels including coconut shells charcoal (CSC), palm kernel shells (PKS), and Empty fruit bunch (EFB) on H 2 % was also investigated. H 2 % was 47.7% for CSC, followed by 46.3% for PKS and 44.7% for EFB. [ABSTRACT FROM AUTHOR]