Recent progress on the bioconversion of lignocellulose to fuels and chemicals

Abstract

With the continuous strengthening of green and sustainable development, chemical production is entering a new era. Lignocellulose, a widely available renewable biomass, offers potential for biofuel and chemical production; however, its complex structure hinders efficient utilization. Accordingly, this review will first summarize the required enzymes for its degradation based on the structural characteristics of lignocellulose. Oriented by bioconversion technology, pretreatment methods of lignocellulose are elaborated in detail. Additionally, we introduce four mainstream process configurations including separate hydrolysis and fermentation, simultaneous saccharification and fermentation, simultaneous saccharification and co-fermentation, consolidated bioprocessing. As is well known, the production of biofuels and bio-based platform chemicals is critically important for ensuring energy security and reducing greenhouse gas emissions. Thus, this review summarizes typical high value-added products synthesized from lignocellulose, including biofuels (bioethanol, biobutanol, biodiesel, biohydrogen), bulk chemicals (lactic acid, succinic acid, malic acid), and fine chemicals (vanillin, xylitol, carotenoids). Finally, we discuss the technological challenges and innovative solutions of lignocellulose bioconversion, while briefly mentioning the life cycle assessment.