Microwave pyrolysis coupled with conventional pre-pyrolysis of the stalk for syngas and biochar

The study presented a novel approach microwave pyrolysis coupled conventional pre-pyrolysis (MCCP) to dispose of the stalk for syngas and biochar. Impacts of preheating temperature (250 similar to 450 degrees C) on pyrolysis property and products characteristics were investigated. Compared with microwave-assisted pyrolysis (MAP), the initial time for rapid temperature ramp in MCCP was distinctly advanced from 124 s to within 20 s; the biochar yields significantly increased from 24.19% to 33.24%, and the H-2 content of syngas in the second stage reached up to 64.65%. The biochar from MCCP had higher carbon content (greater than 70%), carbon retention (greater than 50%), and BET surface area (141.69 m(2)/g) than MAP. A high degree of aromatization and complete carbon skeleton structure was observed in the biochar from MCCP. Finally, a mobile application system based on MCCP was proposed, increasing the energy efficiency from 13.5 similar to 27% (MAP) to 58.5 similar to 76.5%.

Automated summary

The study introduces a novel approach, microwave pyrolysis coupled conventional pre-pyrolysis (MCCP), to dispose of stalks and obtain syngas and biochar. The impacts of preheating temperature on pyrolysis property and product characteristics were investigated, revealing that MCCP had better performance and efficiency compared to MAP.