Integrated Production and Separation of Furfural Using an Acidic-Based Aqueous Biphasic System

An integrated platform for furfural production and separation from xylans using an acidic aqueous biphasic system (AcABS) is described here. The AcABS is composed of the ionic liquid (IL) tributyltetradecylphosphonium chloride ([P444(14)]Cl) and hydrochloric acid (HCl), the latter acting both as a catalyst and phase-forming agent. Furfural is produced in the AcABS biphasic regime under microwave irradiation, being continuously extracted to the IL-rich phase. Operating conditions (reaction time, temperature, HCl and IL wt %, and solid/liquid ratio) were initially screened to identify the most relevant parameters affecting furfural production, being optimized using a response surface methodology approach. A maximum furfural yield of 78.8% and an extraction efficiency to the IL-rich phase of 85.5% were attained in 1 min in the microwave reactor, at 140 degrees C and 0.05 S/L ratio, with the ABS formed by 30 wt % IL and 6.5 wt % HCl. Three reaction cycles were performed by reusing the IL, in which 78.0% of furfural could be recovered from the IL-rich phase in all the reaction cycles, without compromising the furfural yield and extraction efficiency. This work demonstrates the potential of acidic-based aqueous biphasic systems as one-step production-separation strategies of high-value platform chemicals, paving the way toward sustainable development within biorefineries.

Automated summary

This study demonstrated the potential of an integrated platform for furfural production and separation from xylans using an acidic aqueous biphasic system. By optimizing operating parameters and reusing the ionic liquid, high furfural yield and extraction efficiency were achieved, paving the way for sustainable development in biorefineries.