Assessment of a protic ionic liquid with respect to fractionation and changes in the structural features of hardwood and softwood

In this work, the potential of protic ionic liquid, triethylammonium hydrogen sulfate (TEAHSO₄) was shown regarding the pretreatment of the hardwood, hornbeam and softwood, pine at different temperatures and times. TEAHSO₄ was effective for lignin extraction and enhancing the enzymatic digestibility of both the biomass. Cellulose content of hornbeam increased to 85% with 87% lignin extraction from the biomass subjected to pretreatment at 150 °C for 3 h which was then readily converted into glucose with 97% yield. On the other hand, pine as a softwood demonstrated more resilience to deconstruction; 76% glucose yield was achieved following the enzymatic hydrolysis of biomass pretreated at 150 °C for 30 min. As put forward in the present work through TEAHSO₄ pretreatment, any lignocellulosic feedstock that can be effectively disassembled into cellulose and lignin should be regarded as high value for the production of liquid and gaseous fuels through thermochemical and biochemical routes.