<p>The agricultural industry and crop-derived residues are receiving attention globally as a feedstock to derive alternate fuels which are not impacting the environment adversely. This study involves design and performance analysis of the circulating fluidized bed gasifier (CFBG) of 15&#xa0;kW thermal capacity which can handle different types of residues as a feedstock. Air gasification of different wastes was carried under variable conditions to describe the relationship among syngas quality and operating conditions for the CFBG system. Rice husk, sawdust and sugarcane bagasse were selected as a feedstock. During the experiments, equivalence ratios (ER) were varied from 0.18 to 0.4. Performance of the CFBG system in terms of variation in producer gas composition, reactor temperature profile, LHV of syngas, carbon conversion efficiency, solid carryover rate, tar yield and cold gas efficiency was investigated. For sawdust, a maximum cold gas efficiency of 65% at ER 0.33, carbon conversion efficiency of 89% at ER 0.4 and H₂ content of 13.8% at ER of 0.33 were reported. The highest tar content of 13.8&#xa0;g/m³ was reported for rice husk at the ER of 0.18. For bagasse highest syngas LHV of 5.8 MJ/m³ was reported at the ER of 0.33. The recirculation of bed materials and unburned biomass particles through loop seal influenced the reactor temperature profile and tar content in the syngas. The outcome of the study provides fundamental details regarding quality of the syngas which can be generated in CFBG system using various residues.</p> Graphical Abstract <p></p>