How to make furfural and HMF production greener? Lessons from life cycle assessments

Abstract

As part of the increasing demand for sustainable methodologies, there is an ongoing need for green and sustainable industrialization of platform chemical production, including furfural and 5-hydroxymethylfurfural (HMF). While the existing literature contains a wide range of reviews on furanic compounds, there is a notable lack of coverage of the sustainability, environmental and economic perspectives. Thus, this review presents a comprehensive survey and critical analysis regarding the production of furanic compounds based on existing life cycle assessments (LCAs), elucidating the effects of feedstock, solvent, catalyst, energy resource, mass efficiency, and energy efficiency on environmental impact. Several green solvents with the greatest potential for future biorefinery scenarios were carefully chosen, guided by LCA results, cost-effectiveness, safety and health. In addition, this review thoroughly examines the benefits and drawbacks of selected solvents, investigates several application scenarios, and outlines future research directions. Meanwhile, the potential choice, research and development of feedstocks and catalysts are discussed, incorporating the LCA investigations to provide potential directions for enhancing the sustainability and viability of furanic compounds through the improvement of synthetic routes. Moving forward, we recommend macroalgae as a new feedstock that has the potential to produce furanic compounds because of its high carbohydrate content, significant carbon sink capacity, and simultaneous capacity for domestic sewage treatment. To accelerate the green and cost-effective development of biomass pretreatment, HMF and furfural in biorefineries from lab scale to commercial scale needs a greater use of ex-ante LCA and TEA methodologies integrating chemical process simulations, artificial intelligence, and other computational techniques.