Separation and characterization of cellulose I material from corn straw by low-cost polyhydric protic ionic liquids

摘要

Separation of cellulose I (TM) material from biomass with high efficiency by using ionic liquid (IL) is still challenging. In this work, three low-cost polyhydric protic ammonium-salt ILs (about $1000/t) based on sulphonethane anion were synthesized via one-step protonation reaction and firstly applied in the pretreatment of corn straw. After study on the influence of selected process parameters, such as extraction time, extraction temperature and the IL recycling, 2-hydroxy-N-(2-hydroxyethyl)-N-methylethanaminium methanesulfonate ([BHEM]mesy) exhibits the highest efficiency with the content of cellulose up to 90 wt% in the cellulose material obtained at 140 A degrees C for 6 h. Characterization analysis of the cellulose products certified that the cellulose materials maintain the same crystal structure of cellulose I as native corn straw. Gas chromatography-mass spectrometry and mass spectrometry methods were conducted to explore the possible separation mechanism. [BHEM]mesy shows the prospect of industrialization for cellulose I material separation from biomass owing to its low-cost and high-efficiency characteristics.