Continuous extraction of xylose to Dowtherm A via esterification with 1-napthalene boronic acid from bagasse acid hydrolysate

Previous studies identified esterification with 1-napthalene boronic acid and subsequent extraction to Dowtherm A as a means of separating xylose from an aqueous stream. It was also shown that the xylose-boronate ester can be converted to furfural at high yields. To further investigate the possibilities of a large-scale continuous process for converting biomass (in this case sugarcane bagasse) to furfural, the reactive extraction is further studied in this work. A kinetic model for the extraction rate of xylose in both a batch and continuous system is made and verified using a model solution of xylose in water, the findings are also confirmed for actual biomass, and a multistage countercurrent mixer-settler cascade is modeled. This demonstrated the possibility of recovering more than 90 % of the xylose in a 50 g/L feed stream with 3 stages and a total residence time of 10 minutes. • A kinetic model of the extraction of xylose from aqueous streams using boronic acids was developed. • The model can predict the extent of extraction for a CSTR, also experimentally verified. • An extraction cascade of 3 stages and residence time of 11 min could extract 90 % of the xylose. • All findings were also validated with real bagasse hydrolysate.