Low temperature gasification of olive kernels in a 5-kW fluidized bed reactor for H2-rich producer gas

Air gasification of olive kernels in a 5 kW bench scale, bubbling fluidized bed gasifier, aimed at H2 enrichment of the producer gas, was the target of this study. The effects of reactor temperature (T = 750–850 °C) and equivalence ratio (ER = 0.2–0.4), representing the under stoichiometric amount of air inserted into the reactor to that necessary for complete combustion, on producer gas quality were determined. The experimental results revealed that producer gas H2 content increased at the temperature of T = 750 °C and ER = 0.2, resembling the high-temperature pyrolysis conditions that favour H2 and CO production. Further increase in ER deteriorated producer gas quality, decreased H2 content and favoured CO2, thus lowering producer gas heating value. The data obtained from several experiments indicate that olive kernels produced a medium heating value gas (LHV = 6.54 MJ/Nm3) at 750 °C and ER = 0.2, while H2 and CO production were maximized at the same conditions (H2: 24%vv, CO: 14.3%vv).