The mechanism of wet/dry torrefaction pretreatment on the pyrolysis performance of tobacco stalk.

In this work, the influence of dry/wet torrefaction with additives on the pyrolysis performance was investigated. The results showed that the content of phenols and ketones (62% and 42%) was improved and the content of acids decreased from 35% to 4% due to the increase of lignin content in torrefied char. Moreover, the content of aromatic hydrocarbon reached 22%. The mechanism showed that the conversion of "CO/CO" into states of "aromatic CC/CC", the removal of hemicellulose and the formation of pseudo-lignin during wet/dry torrefaction were the key factors for the enrichment of aromatic hydrocarbon. The research supplied an effective and original method for obtaining high value aromatic chemicals from the agricultural and forestry waste via the wet/dry torrefaction pretreatment combining with pyrolysis.