Reactive Extraction Enhanced by Synergic Microwave Heating: Furfural Yield Boost in Biphasic Systems

Reactive extraction is an emerging operation in the industry, particularly in biorefining. Here, reactive extraction was demonstrated, enhanced by microwave irradiation to selectively heat the reactive phase (for efficient reaction) without unduly heating the extractive phase (for efficient extraction). These conditions aimed at maximizing the asymmetries in dielectric constants and volumes of the reaction and extraction phases, which resulted in an asymmetric thermal response of the two phases. The efficiency improvement was demonstrated by dehydrating xylose (5 wt % in water) to furfural with an optimal yield of approximately 80 mol % compared with 60–65 mol % under conventional biphasic conditions, which corresponds to approximately 50 % reduction of byproducts. It's not just a phase: Reactive extraction of xylose to furfural is boosted by a synergic combination of microwave heating and biphasic operation to deliver a hot aqueous phase for reaction and a colder organic phase for extraction.