Process simulation of fast pyrolysis of Wolffia globosa using aspen plus for sustainable bio-oil production

Abstract

Fast pyrolysis has emerged as an efficient thermo-chemical route for converting biomass into liquid fuels under moderate temperatures and short vapor residence times. This study presents a systematic Aspen Plus simulation framework for the fast pyrolysis of Wolffia globosa, a protein-rich aquatic plant with low lignin and high volatile matter content. The model employed a multi-stage RYield reactor configuration to represent progressive decomposition processes, integrated with separation and quenching units to preserve vapor quality and bio-oil composition. To establish model credibility, the framework was benchmarked against a published sawdust simulation and compared with reported pyrolysis trends of aquatic biomass. Simulations were performed across 400–600 °C with a fixed vapor residence time of 1.25 s. The results demonstrated that bio-oil yield increased with temperature, peaking at 58.62 wt% at 550 °C before slightly declining at higher temperatures due to secondary cracking. At this optimum condition, the simulated bio-oil contained approximately 89.25% organic compounds and 10.75% water by mass, indicating favorable properties for downstream upgrading. Gas yields increased monotonically with temperature, while char yields decreased, reflecting enhanced volatilization at higher thermal severity. The validated model showed less than 10% deviation from literature data and provides a replicable approach for simulating protein-rich aquatic biomass. Overall, this study highlights Wolffia globosa as a viable feedstock for sustainable bio-oil production and offers a transparent simulation methodology that can support future optimization and integration with circular wastewater treatment systems.