Modeling and simulation of catalytic conversion of empty fruit bunch (EFB) into polylactic acid

This research aims to model and simulate the catalytic conversion of empty fruit bunch (EFB) into polylactic acid (PLA), carried out with the Aspen Plus V10 simulator. The model was developed to represent each of the five process stages of conversion of EFB to PLA: pretreatment of EFB, catalytic conversion of glucose and xylose to reflect the major component of EFB into lactic acid, catalyst separation, lactic acid purification, and lactic acid polymerization to PLA. The simulation results were then validated with the results of Jauhari's (2017) and Christopher and Natanael's (2020) experimental data. Feed compositions and operation conditions, including temperature, pressure, and reaction time, were extracted from experimental data. The EFB pretreatment was conducted by alkaline hydrothermal method, followed by catalytic conversion of the pretreated EFB using PbCl2 catalyst producing lactic acid as a platform chemical. The lactic acid was purified in two steps: esterification-hydrolysis and steam distillation. The polymerization of lactic acid applied a direct polycondensation method to generate PLA with high purity. In Aspen Plus, modeling and simulation of the pretreatment by the alkaline hydrothermal method used a yield-type reactor in the software, where the EFB was modeled as cellulose, hemicellulose as xylan, lignin, and extractive as biomass model. The simulation produced lactic acid with a recovery of 5.32%-weight based on pretreated EFB, in accordance with the experimental data, with a minimal 5-hydroxymethylfurfural (HMF) content of 0.08%-m/m. Furthermore, the simulation resulted in PLA with high purity, 80%-m/m PLA with a molecular weight (MW) of 68002.2 gram/mol, while the experimental data yielded 9.90%-m/m of PLA with an MW of 76489 gram/mol and no impurities.