The present investigation discusses syngas production through gasification from six different bamboo biomass species available in India’s northeast region (Mizoram). The thermochemical conversion of biomass to syngas is accomplished in a novel double-tapered reactor. The pre-processing stage of biomasses includes various shredding, drying, and sieving methods. In the processing stage, the biomass (20 g) is fed to the reactor regularly. The heating element in the interior of the reactor supplies the heat required (600–1000 °C) for the combustion and gasification of biomass samples. The influence of various particle sizes on bed voidage, pressure drop, bed height, suspension density, gas yield, heat transfer, and carbon conversion efficiency is studied. The tapered reactor enhanced the bed hydrodynamics. It is observed that the H2 and CO2 composition increases with the temperature (> 900 °C), whereas the CO composition is reduced as a result of the shift reaction. However, the CH4 yield is enhanced at a temperature (< 800 °C) but lessened at higher temperatures due to a reduction in moisture content. The carbon conversion efficiency (CCE) and the dry gas yield (YG) values obtained are better for the particle size of 1.18 mm than the other particle sizes. The energy from biomass resources is promising regarding sustainability, availability, and efficacy. The current approach discusses the syngas generation from bamboo biomass through gasification under varied temperature ranges (600–1000 °C), equivalence ratio (0.2), particle sizes (380 µm, 600 µm, and 1.18 mm), superficial velocity (0–2 m/s) in a pilot 5 kg/h DTBFBR of height 1.2 m and maximum inner diameter of 16.5 cm.