Composition | Untreated | AFEX | DA | IL |
|---|
Glucan | 33.4 ± 3.2 | 33.5 ± 0.5 | 59.1 ± 3.0 | 46.9 ± 1.9 |
Xylan | 24.9 ± 2.0 | 24.8 ± 0.9 | 6.5 ± 0.1 | 29.8 ± 0.5 |
Arabinan | 3.7 ± 0.5 | 3.3 ± 0.4 | 3.6 ± 0.1 | 0.3 ± 0.0 |
Acetyl | 2.1 ± 0.2 | 0.0 ± 0.0 | 0.6 ± 0.6 | 1.5 ± 0.1 |
Acid insoluble lignina | 17.2 ± 0.6 | 12.2 ± 0.2 | 22.2 ± 0.2 | 2.7 ± 0.5 |
Ash | 3.6 ± 0.0 | 4.4 ± 0.3 | 2.5 ± 0.0 | 1.3 ± 0.26 |
Extractives | 10.4 ± 0.4 | 24.8 ± 0.8 | 15.4 ± 0.8 | 13.1 ± 2.0 |
- All experiments were carried out in triplicates with averages and standard deviations reported here.
- aThe acid insoluble or Klason lignin analysis method was modified to use 47 mm, 0.22 μm pore size mixed cellulose ester filter disks (Millipore Corporation, Bedford, MA, USA) during the filtration process instead of the fritted crucibles. The filtered lignin residues were dried overnight in a desiccator prior to weighing. AFEX does not remove any particular components during pretreatment. Ammonia is evaporated and all the ammonia soluble biomass components condense on the surface of the biomass[13]. However, some reactions do occur to lignin during AFEX, transforming Klason lignin (acid insoluble) to acid soluble lignin, which was not quantified in this study. AFEX, ammonia fiber expansion; DA, dilute acid; IL, ionic liquid; MSU, Michigan State University.
