An optimisation study on biomass delignification process using alkaline wash

A statistical based study employing response surface method (RSM) was conducted to ascertain the optimum pretreatment conditions using an alkaline wash technique i.e. at different temperature, time and base concentration using Malaysian oil palm empty fruit bunches (EFB) as a model substrate. Strong acid-dilute acid hydrolysis and dietary fibre methods were used in order to determine structural carbohydrates and lignin content of pretreated EFB and analysed using one-way analysis of variance (ANOVA). Based on the RSM model, 17 runs of different pretreatment conditions were carried out. ANOVA analysis on the different techniques yielded an F value of 5.32 leading to the rejection of null hypothesis. As such, both techniques were determined to be statistically different. Response surface model with quadratic function was generated for biomass pretreatment using alkaline wash which has indicated that sodium hydroxide concentration is the most important factor in determining lignin removal, followed by time of reaction. The final lignin content of pretreated biomass shall be 9.04 wt.% which is 62.7% of lignin removal.