Characterization and pilot scale fluidized bed gasification of herbaceous biomass: A case study on alfalfa pellets

Abstract Pilot-scale bubbling fluidized bed gasification tests of alfalfa pellets were performed at two different operational periods ranged on the basis of the two given equivalence ratio (ER) (the ratio between actual air and the stoichiometric air) namely as 0.25 and 0.30. During the test, the solid feeding rate was kept constant at 4.7 kg/h while the air input was varied and thus the ER. Increasing air from 4.16 to 4.99 N m3/h contributed to the evolution pattern of several parameters such as the rise in gas lower heating value (LHV) and gas yield, the average maximum of which were 4.2 MJ/N m3 and 1.5 N m3/kg respectively. Gas composition was mainly boosted by the concentration of CO, a…