Pretreatment strategies to improve anaerobic biodegradability and methane production potential of the palm oil mesocarp fibre

• Effect of physicochemical pretreatments on the anaerobic biodegradability of the oil palm mesocarp fibre.
• Delignification and sugar solubilisation of the lignocellulosic biomass.
• Methane production from the oil palm mesocarp fibre.

The use of lignocellulosic waste as a power source typically requires pretreatment of the material, either for sugars solubilisation or lignin removal. We evaluated the acid, alkaline and hydrothermal pretreatments on palm oil mesocarp fibre in order to increase the anaerobic biodegradability and methane production potential (MPP). The results show that the best MPP (199 L CH4/kg substrate) was achieved by using acid pretreatment with a reaction time of 34 min, temperature of 103 °C and [HCl] of 1.97 M. However, the energy generated from methane is lower than merely burning the bagasse, and probably the lignin with high added-value has to be recovered for improving sustainability and profitability. In this case, the alkaline pretreatment with a reaction time of 47 min, temperature of 183 °C and [NaOH] of 1.8 M extracted 91% of the lignin present in the fibre, and the hydrolysate could generate 180 L CH4/kg substrate.