The Effect of Solvent Polarity on Autocatalytic Furfural Production Confirmed by Multivariate Statistical Analysis

Autocatalytic dehydration of xylose to furfural was studied in pure aqueous and monophasic organic/water mixtures to determine the effect reaction media and conditions have on conversion and yield. This study identified that the severity (R_o) of the reaction and polarity, as determined by the Hansen Solubility Parameter, δ_P, strongly correlate with xylose conversion and furfural yield. Increasing the R_o and δ_P increased both conversion and yield in pure aqueous and organic/water mixtures of sulfolane, γ-butyrolactone, γ-valerolactone, γ-hexalactone, and tetrahydrofuran. Additionally, it was found that at a specified R_o and δ_P, similar conversions and yields were achieved using different combinations of time, temperature, and solvent mixture. Using principal component analysis and projection to latent structures, a semi-empirical model was developed that provided estimates of xylose conversion and furfural yield over a range of experimental R_o and δ_P values.