A Laboratory-Scale Moving-Bed Biomass Gasifier with Controlled Solid Displacement: Design and Performance Evaluation

Abstract

This study reports on the design, construction, and operation of a laboratory-scale biomassgasification reactor, together with the procedures used to define and evaluate key operationaland performance variables, including piston velocity, nominal biomass residencetime, airflow rate, gas yield, lower heating value, and gasification efficiency. The unit is amoving-bed reactor operating in co-current gas–solid mode and reproducing key featuresof downdraft-like gasification, allowing the identification of the four main reaction zones:drying, pyrolysis, oxidation, and reduction. The reactor exhibits simple operation andhandling and, notably, enables controlled axial displacement of the biomass bed throughthe reaction zone, allowing the nominal solid residence time in the heated zone to beadjusted through piston motion. In addition, the gasification of Spartina argentinensis wasinvestigated in order to evaluate the functionality of the system and to assess reactor performanceunder selected operating conditions. At operating temperatures of 800–850 ◦Cand an equivalence ratio of 0.2, gas yields exceeded 60 wt%, gasification efficiencies wereabove 50%, and the product gas reached heating values close to 1000 kcal Nm−3, indicatinga favorable fuel quality of the product gas. These results confirm the potential ofthe proposed reactor as a useful experimental platform For the investigation of biomassgasification under controlled laboratory conditions.