Co-production of syngas and activated carbon from bamboo through the 340 kWe pilot-scale downdraft gasification gasifier: Optimal the air flow rate and activation condition

Moso bamboo, a fast-growing lignocellulosic biomass, holds promise as a feedstock to produce bio-energy through the thermochemical conversion technology. This study developed a 340 kWe pilot-scale downdraft fixed-bed gasification system to co-produce syngas and activated carbon from bamboo, and systematically evaluated the gasification performance and bio-char valorization. The impact of air flow rate was investigated, revealing that increasing the supply from 400 to 800 m3 h−1 significantly improved producer gas quality, with optimal syngas composition reaching 18.5% for CO, 2.5% for CH4, 16.7% for H2, and 13.1% for CO2, and a LHV of 5.20 MJ·Nm−3. During a 24-h continuous high-load operation, the system achieved stable performance with a feedstock consumption rate of 700 kg h−1, a gas output capacity of 1400 m3 h−1, a cold gas efficiency of 57.87%, and a power generation of 340 kWe. The resulting bamboo bio-char was successfully upgraded via the KOH activation approach. Under optimal conditions (KOH-to-bio-char mass ratio of 3:1, activation temperature of 900 °C, activation time of 1h), the activated carbon exhibited the highest specific surface area of 1338.55 m2 g−1 and a pore volume of 0.900 cm3 g−1, and demonstrated effective adsorption capacity for methyl orange with the maximum capacity of 212.77 mg g−1. This pilot-scale study validates bamboo as a viable feedstock and presents a sustainable poly-generation pathway of syngas and bio-char, which integrates clean energy generation with high-value utilization of biomass residues.