Sugarcane bagasse gasification: Simulation and analysis of different operating parameters, fluidizing media, and gasifier types

Abstract

Sugarcane bagasse gasification is a promising thermochemical process that converts this residue mainly into syngas, which may be applied to generate heat, electricity, and liquid fuels. However, little attention has been given to the study of bagasse gasification conditions that generate syngas for future production of liquid fuels and chemicals. Therefore, this work aimed at studying several sugarcane bagasse gasification scenarios in Aspen Plus™ to obtain syngas mixtures to be further conditioned for synthesis processes. The scenarios included the study of the influence of operational parameters (temperature, pressure, steam-to-biomass ratio S/B, and moisture content), fluidized bed configurations (bubbling and circulating), and gasifying media (steam and steam-O2) on syngas composition and process performance. Among the operating parameters, temperature was crucial for higher H2 and CO production, CO2 consumption, higher syngas lower heating value (LHV), and higher cold gas efficiency (CGE). Also, S/B was the only key factor to adjust the H2/CO ratio. In the gasifier configuration analysis, circulating fluidized bed reactor was the most suitable gasifier in most assessed scenarios, since it led to higher H2 and CO generation, lower CO2 and CH4 production, as well as higher H2/CO, dry syngas flow rates, and CGEs. The use of oxygen as an oxidizing agent decreased H2 content and increased CO concentration, and reduced syngas H2/CO ratio, LHV, and CGE. The steam-blown circulating fluidized bed was advised for future synthesis processes, and its corresponding response surfaces for H2/CO ratio and CGE were obtained.