Integrated, multi-product lignocellulosic (woody biomass) biorefineries are still in their infancy, with few projects having progressed past pilot stage. Bioethanol plants based on corn, wheat and sugar cane are able to create value from multiple product streams (spent grain for animal feed, carbon dioxide for beverages) to subsidise the cost of the biofuel. Lignocellulosic biorefineries must follow this pattern to become economically viable, taking advantage of the inherent diversity of co-products available (biochar for soil improvement, chemical intermediates from sugar chemistry) to create added value over the primary bioproduct (sugar for fermentation).

In this project, we will develop more material-efficient platform chemicals from biomass whose production can be integrated with biomass fractionation to create a diverse array of platform products for further value creation. By combining catalytic chemistry into biomass pretreatment, we will be able to produce higher yields of these platform chemicals while simultaneously increasing the value of co-products. This will be done by taking advantage of the chemistry inherent to biomass fractionation (separation of cellulose from lignin in wood) and leveraging our developed process based on organic salts (ionoSolv) to achieve production at milder temperatures. The mild temperatures will enable us to avoid hemicellulose and lignin degradation, instead providing chemical intermediates in the synthesis of bio-based detergents, bioplastics and resins.

The impact will be a technological roadmap for the integration of co-product valorisation alongside cellulosic sugar production. There is current demand for cellulosic sugars and bio-based products in the UK bioeconomy. Our developed multi-product biorefinery concept will be validated through techno-economic and life cycle assessment to establish the roadmap for deploying a scale-matched biorefinery concept that can be adapted and adopted across a range of bioindustries.

This project is led by Jason Hallett and Pedro Nakasu, Imperial College London.

Progress Update 2025

• The team have developed and successfully tested an integrated reactor for biomass fractionation (e.g., sugarcane bagasse) using ionic liquids at 120–170 °C. The system features a pressurized condenser that maintains water levels (10–20 wt%) while continuously removing furfural and recycling water to protect cellulose from over-dehydration.
• Using [DMBA][HSO₄] as the ionic liquid, optimization studies showed that the best conditions—170 °C, 10 wt% solids loading, and 1–2 mm particle size—produced a 77% furfural yield. The solvent showed excellent recyclability, with up to five reuse cycles achieving 98% recovery and a steady 70% yield.
• The reactor design has since been customized for ongoing pretreatment studies.
• In parallel, the team are also exploring levoglucosan (LGA) production using ionic liquids, with [EMIM][Cl] identified as the most effective solvent. Optimization of this process is currently underway.