Hydrogen fermentation and lignin pyrolysis of wheat straw via SPORL pretreatment

Agriculture biomass is a kind of renewable resource for renewable energy production. Current lignocellulose pretreatment methods face challenges in balancing efficient fermentation with lignin valorization. In this study, SPORL pretreatment for enhancing wheat straw fermentation and the valorization of residual lignin through pyrolysis was investigated. The results suggested that the SPORL pretreated wheat straw has a high glucose conversion rate of about 94.5 % at a pH of 5.5–6.0 after 72 h of enzymolysis, and the maximum H 2 fermentation yield was 100.42 mL/g. The residual lignin was characterized and subjected to pyrolysis, and the results showed that the maximum weight loss temperature and residual carbon rate of lignin decreased with the increase of sulfite dose. Following pyrolysis at 600 °C for 30 min, the lignin yielded approximately 22 % bio-oil and 33 % biochar. GC-MS analysis of the bio-oil showed that it contained abundant acetic acid (36 %) and phenolic compounds (20 %), indicating the potential for high-value product conversion. This study provides a comprehensive method for the conversion of wheat straw into bioenergy products, showcasing the economic and ecological benefits of integrated biomass utilization. • Carbohydrate fermentation combined with lignin pyrolysis is applied for biomass conversion. • SPORL treatment enhanced the enzymatic hydrolysis and hydrogen production. • The glucose conversion rate of 94.5 % was reached at pH of 5.5–6.0 after 72 h enzymolysis. • The maximum hydrogen fermentation yield can reach 100.42 mL/g at the optimal condition. • Lignin was converted into 22 % and 33 % bio-oil and biochar, respectively, at 600 °C for 30 min.