(411a) Furan Production from Biomass Hydrolysates: Scale-up of a Novel, High-Yield “Sire” Process

Lignocellulosic biomass is a sustainable feedstock for production of furans – 5-hydroxymethy furfural (HMF) and furfural – versatile platform molecules that can be converted to drop-in fuels and precursors for synthetic materials. Lack of efficient lignocellulosic sugars-to-furan pathways (especially HMF) constitutes a major barrier to the industrial production of furans. We have recently demonstrated high yields of furans from biomass hydrolysates using a novel Simultaneous-Isomerization-Reactive-Extraction (SIRE) followed by Back-Extraction (BE) and dehydration process (Green Chem., 2017, 19, 1782). We are now in the process of developing a continuous-flow, meso-scale (5L) SIRE-BE system and this presentation will discuss furan production using concentrated AFEX (Ammonia Fiber Expansion) treated lignocellulosic biomass hydrolysate (60 g-total sugars/L). The continuous flow system consists of a packed bed Isomerization column containing immobilized glucose/xylose isomerase to convert aldose hydrolysate sugars (glucose and xylose) to more reactive keto-forms (fructose and xylulose). The isomerization column is closely coupled with a hollow fiber membrane module to facilitate continuous Reactive Extraction of the ketose sugars into an octanol phase. The aqueous- and organic- phases flow in the lumen- and shell- sides of a hydrophobic polypropylene module. Finally, ketose sugars Back Extracted from octanol into an immiscible acidic ionic liquid where they are dehydrated to furans. A key aspect of the scale-up is to develop and validate mathematical models that describe the mass transfer processes during Isomerization and Reactive Extraction. We will present data from continuous-flow studies and compare experimental results with model predictions. Techno-economic feasibility and sensitivity analysis will also be presented to assess the potential of the SIRE-BE process to provide low-cost furans for drop-in fuels and polymer precursors.