Study of gasification behavior for a biorefinery lignin waste in a fluidized bed gasification reactor

Abstract

Lignocellulosic biorefineries, paper and pulp industries across the globe can convert cellulose and hemicellulose parts of the biomass into higher valued products. However, lignin from biomass is an underutilized biorefinery waste. Value-added applications of lignin waste should be investigated to produce low-molecular-weight compounds as an alternative to petrochemical compounds. Valorization and lignin recovery play an important role in ‘green shifts’ for such industries. In this work, the authors performed gasification of lignin pellets obtained from one biorefinery located in Finland. A 20-kW pilot-scale bubbling fluidized bed gasifier was used for the experiments. A computational particle fluid dynamics model based on a multi-phase particle in cell approach was developed for the same process. The developed model was validated against the experimental results.

The experimental results showed good conversion of lignin pellets into permanent light gases such as carbon monoxide, hydrogen, methane, etc. The average production of product gas and the lower heating value were 5.74 Nm³/hr and 4.95 MJ/Nm³, respectively. The average molar gas compositions obtained from the experimental study were 0.04 for CH₄, 0.16 for CO, 0.15 for CO₂, 0.13 for H₂ and 0.51 for N₂.