Influence of feeding ratio on steam gasification of palm shells in a rotary kiln pilot plant. Experimental and numerical investigations

This paper presents experimental and numerical results on steam gasification of palm shells in a rotary kiln pilot plant. Both the process performance and gas features have been evaluated varying the steam-biomass ratio (SBR), defined as the mass of steam divided by the mass of palm shells. First, some experimental tests have been performed. Then, the obtained experimental results have been used to verify the consistency of a numerical model developed with the aid of the commercial code ChemCAD®. cal results showed that the gas energy content decreases as the SBR increases as well, achieving a maximum value for SBR = 0.6 that produced a gas which volumetric composition N2 free is H2 = 40.4%, CO = 24.1%, CO2 = 21.7%, CH4 = 12.2%, C2H4 = 1.7% and in correspondence of which the lower heating value (LHV) is equal to 12 MJ m−3 in normal conditions. SBR values higher than 0.6 do not produce a further increase of the gas yield, rather require a greater amount of input energy for heating the steam from the room temperature to the process temperature.