Effect of pretreatment with hydrogen peroxide at different pHs on corn stalk: Characterizations of structure, composition, and pyrolysis properties

Appropriate pretreatment plays a pivotal role in biomass pyrolysis as it facilitates high-value utilization of pyrolysis products. In this study, hydrogen peroxide pretreatment with cleanliness, economy, and efficiency was applied for fast pyrolysis of corn stalks. The effects of pyrolysis temperature, hydrogen peroxide pretreatment, and different pHs on the structure of corn stalks and the properties of resultant pyrolysis products were investigated. The results revealed that the pretreatment could effectively promote lignin depolymerization and significantly reduce the reaction activation energy (E). Meanwhile, the pretreatment increased the cellulose content and removed the majority of alkali and alkaline earth metals from the biomass. The removal of lignin and ash by the pretreatment was affected by the pH of the hydrogen peroxide solution. Moreover, the composition of bio-oil changed significantly. Among them, the relative content of levoglucosan in the bio-oil from untreated raw material was only 1.38 %. After pretreatment, the relative content of levoglucosan was up to 14.5 %. The present findings offer valuable guidance for the further exploration and exploitation on hydrogen peroxide pretreatment for depolymerization of woody fibrous biomass as well as for the preparation of high-value chemical products.

Automated summary

Hydrogen peroxide pretreatment was applied for fast pyrolysis of corn stalks, and it was found that the pretreatment effectively promoted lignin depolymerization and decreased the reaction activation energy. The pretreatment also increased the cellulose content and removed alkali and alkaline earth metals from the biomass. The pH of the hydrogen peroxide solution affected the removal of lignin and ash by the pretreatment, and the composition of bio-oil changed significantly, with a significant increase in the relative content of levoglucosan after pretreatment.