Furfural and levoglucosenone production from the pyrolysis of ionic liquid pre-treated sugarcane straw

The current work focuses on the comparison of renewable choline cation-based ionic liquids (ILs) with imidazolium cation-based ILs for their delignification performance. Choline cation-based ILs removed a higher percentage of lignin (78.1-83.7% vs. 51.4-64.5%) and hemicellulose (64.7-72.8% vs. 7.1-29.9%) from sugarcane straw pre-treatment compared to imidazolium cation-based ILs. This was mainly attributed to the presence of fewer alkyl group and extra -OH group in choline cation. In general, ILs pre-treatment significantly increased the volatile matter and reduced fixed carbon in regenerated cellulose-rich material. Higher content of cellulose and higher crystallinity in the case of choline-based ILs enhanced the production of furfural and levoglucosenone from the pyrolysis of regenerated cellulose rich material. On the contrary, the presence of higher content of amorphous cellulose from imidazolium-based ILs, particularly 1-ethyl-3-methylimidazolium acetate produced gamma-butyrolactone. Therefore, ILs pre-treatment can be favourable for the selective production of platform chemicals via pyrolysis route. [GRAPHICS] .

Automated summary

The study focuses on comparing renewable choline cation-based ionic liquids (ILs) with imidazolium cation-based ILs for delignification performance, where choline cation-based ILs showed higher effectiveness in lignin and hemicellulose removal, resulting in increased volatile matter and reduced fixed carbon in regenerated cellulose-rich material. Choline-based ILs also enhanced the production of furfural and levoglucosenone, while imidazolium-based ILs, particularly 1-ethyl-3-methylimidazolium acetate, produced gamma-butyrolactone due to higher content of amorphous cellulose. Overall, ILs pre-treatment can favor the selective production of platform chemicals via pyrolysis route.