Furfural Production by Continuous Reactive Extraction in a Millireactor under the Taylor Flow Regime

This study demonstrates the use of a millireactor as intensified technology for the continuous production of furfural via acid dehydration of xylose in a biphasic media. Very rapid extraction of furfural, aided by fast mass transfer rates, is key to preventing furfural subsequent degradation. Thus, by operating at elevated temperatures (i.e., 150-190 degrees C), it is possible to maintain high furfural selectivity (ca. 70%) at high xylose conversion (ca. 80%) and very short residence times (up to 2.5 min). A reaction mechanism is proposed based on the observed conversion-selectivity trends, and on the analysis of product distribution. The contribution of humins to the carbon balance is remarkably low due to the high furfural extraction rates achieved in the millireactor. Through first-principle reactor modeling, we further demonstrate the potential of combining intensified reactor technologies with the extractive synthesis of furfural and show that solvent optimization will be crucial to boost furfural selectivity above 80%.