Synthesis, pretreatment, and recovery of [TEA][HSO4] ionic liquid for OPEFB lignocellulosic transformation

Abstract

In recent years, various studies have been utilized lignocellulosic biomass from oil palm empty fruit bunches (OPEFB) to be converted into bioethanol fuels. In this study, we present the techno-economical preparation for biomass pretreatment based on triethylamine hydrogen sulfate ([TEA][HSO4]) ionic liquid. Synthesis, pretreatment, and recovery of [TEA][HSO4] ionic liquid have been carried out via the one-pot method. Based on these results, the synthesized [TEA][HSO4] has been characterized using IR spectroscopy showing the appearance chemical groups such as H, CH3, CN, and SO2. In addition, H-NMR spectroscopy was presenced the CH3CH2- structure towards low ppm. Thermal stability has also demonstrated unique physical properties of ionic liquid (IL) with a melting point of 49°C and a decomposition temperature of 274.3°C. The effectiveness to produce the chemical components shows that the useful use of [TEA][HSO4] was successfully synthesized with an optimum composition of 83% resulting in chemical levels of 45.84% (cellulose), 5.00% (hemicellulose), and 34.40% (lignin). The recovered [TEA][HSO4] with a composition of 90.90% was effective in reducing the lignin content about 80%. These results also depend heavily on the temperature and separation techniques applied during the pretreatment process.