Combustion Analysis of Fixed Beds of Argan Nut Shell (ANS) Biomass in a Batch Type Reactor

Combustion analysis of fixed beds of argan nut shell (ANS) biomass was studied experimentally, for the purpose of testing the potential application of local waste, as direct biofuel for thermal conversion. Particular consideration was given to the influence of air flow rate and fuel particle size on combustion temperature, burning rate, and pollutant emission evolutions. A comparison was performed with wood pellets (WP) which conform to DinPlus standard. The results showed that the combustion process was dominated by flaming mode. The increase of air flow rate leads to the increase of combustion temperature, fuel burn rate (FBR) and decrease of carbon monoxide (CO) and sulfur dioxide (SO
₂
) concentrations until a moderate value (1585 kg m
^-2
h
^-1
), Note that the SO
₂
emissions are mainly coming from combustion of the nourishing tissue of argan almonds. The emissions of nitrogen oxides (NO
_x
) are below 100 ppm (corrected at 10% oxygen) for all experiments. Broken particles induce a higher FBR compared to raw ANS and WP. In this case of particle size, combustion temperature and gas emission values were improved with the highest air flow rate (2642 kg m
^-2
h
^-1
). This leads to the conclusion that broken raw ANS can reach better combustion performances if the required compromise of mixing air and biomass was achieved. The outcomes from the present research can contribute to optimize the ANS burning in small-scale furnaces.