Assessment and comparison of thermochemical pathways for the rice residues valorization: pyrolysis and gasification

Abstract

Abstract The evaluation of lignocellulosic biomass applied to thermochemical routes is postulated as an alternative for the generation of energy from renewable sources. This work aims to compare biorefineries based on two thermochemical routes for the use of raw materials from the rice (husk and straw) production chain in the Department of Sucre-Colombia. Initially, this work analyzes the physicochemical and structural characterization of biomass. Four different scenarios are proposed for the comparison of the valorization from the simulation in Aspen Plus by means of fast pyrolysis and downdraft gasification. The novelty of this work is focused on the identification of the biorefinery with the best techno-economic, energetic, and environmental performance for the generation of electricity and value-added products from rice straw and husk. From an economic perspective, the stand-alone gasification process does not have a positive economic margin, which is an opposite behavior from the pyrolysis process. The biorefinery proposed in scenario 1 (fast pyrolysis of both rice residues) had the best economic and environmental performance with an economic margin of 13.75% and emissions of 2170.92 kgCO2eq/kg for 10 years. However, this scenario was not energetically the best, holding second place due to the feedstock requirements, compared to gasification. The biorefinery scenario 1 has the best performance.