Biomass direct combustion is the main way of biomass energy utilization. Chlorine plays an important role in boiler slagging and corrosion during the combustion of high-chlorine biomass. Low-temperature pyrolysis could make chlorine release and get the low chlorine content biomass. We assessed the effect of the low-temperature pyrolysis intensity on the chlorine content of residual biomass and of the released gaseous species. For this purpose

olive residue was subjected to low-temperature pyrolysis (mild pyrolysis) at furnace temperatures

in the range of 250-400℃ in an inert nitrogen atmosphere. The major chlorinated species in the evolving pyrolysis gas (torgas) were identified as HCl and CH3Cl

and quantified. HCl and CH3Cl will compete Cl which is released during biomass low-temperature pyrolysis and low temperature will promote the conversion of Cl to CH3Cl. When the temperature is below 350℃

CH3Cl is the main product of Cl release and when the temperature arrives at 400℃

HCl will replace CH3Cl to become the main product during low-temperature pyrolysis.