A review on strategies to reduce ionic liquid pretreatment costs for biofuel production

Worldwide demand for renewable energy has promoted the considerable exploration of biofuel production from lignocellulosic biomass. Ionic liquid pretreatment is of great interest to render biomass amenable for biofuel production, however, its unaffordable cost stimulates significant attention to the feasibility of commercialization. This review aims to compile the latest advances with respect to reducing production costs for ionic liquids-based biorefineries. Protic ionic liquids offer relatively low synthesis costs, but excessive antisolvent washing of the pretreated biomass is often inevitable. Recovering ionic liquids requires several separation and purification steps, and the reuse of ionic liquids could significantly lose functionality due to the degradation. It is promising to screen ionic liquids-tolerant enzymes and strains for one-pot saccharification and fermentation without solid --liquid separation, however, there is still a need for subsequent recovery of ionic liquids. Additionally, tech-noeconomic analysis and life cycle assessment are highly recommended to evaluate the economic and environmental impacts.

Automated summary

This review summarizes the latest advances in reducing production costs for ionic liquids-based biorefineries. It discusses the use of protic ionic liquids with lower synthesis costs, but highlights the challenges of excessive solvents washing and the degradation of ionic liquids during recycling. It also suggests the potential of enzyme and strain screening for one-pot saccharification and fermentation, but emphasizes the need for efficient ionic liquid recovery methods.