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. [Display omitted] •Pyrolysis characteristics of corn straw pretreated with H2O2 were investigated.•H2O2 pretreatment increased the relative content of cellulose.•Significant increase in the relative content of levoglucosan up to 14.50 %.•Acids in bio-oil are greatly reduced, as low as 5.33 %.•Degradation mechanism of corn stalk pretreated with H2O2 was elucidated.