| Recovery Scheme 1 |
| single-stage
(lignin precipitation
+ vacuum distillation) |
• simple |
• low lignin recovery
rate |
| |
|
• low GVL recovery
rate |
| |
|
• energy- and time-consuming |
| |
|
• GVL trapped in
sticky residue |
| |
|
• collection
of GVL
in the aqueous distillate |
| Recovery Scheme 2 |
| two-stage (lignin precipitation
+ vacuum distillation) |
• high lignin recovery
rate |
• more
time- and
energy-consuming |
| |
• two recovered lignin
fractions with distinctive molecular weight |
• GVL trapped in
sticky residue |
| |
• more reasonable
GVL recovery rate |
• collection of GVL
in the first-stage aqueous distillate |
| Recovery Scheme 3 |
| lignin
precipitation + liquid
CO2 extraction |
• less energy and
time-consuming than distillation |
• low extraction
selectivity due to diluted feed |
| |
• high lignin recovery
rate |
• significant
GVL
remaining in raffinate due to limited mass transfer |
| |
• two recovered lignin
fractions with distinctive molecular weight |
|
| |
• furanics recovery
in the extract (GVL) stream |
|
| Recovery Scheme 4 |
| liquid CO2 extraction |
• simple |
• significant GVL
remaining in raffinate due to limited mass transfer |
| |
• better energy and
time economy |
•
risk of clogging
by lignin precipitation |
| |
• higher extraction
selectivity |
|
| |
• high lignin recovery
rate |
|
| |
• furanics recovery
in the extract (GVL) stream |
|
| Recovery Scheme 5 |
| vacuum distillation + liquid
CO2 extraction |
|
• clogging of extraction
equipment due to uncontrollable lignin precipitation |
| Recovery Scheme 6 |
| lignin
precipitation + vacuum
distillation + liquid CO2 extraction |
• best extraction
selectivity |
•
more time- and
energy-consuming than recovery scheme 4 |
| |
• high lignin recovery
rate |
• collection
of GVL
in the aqueous distillate |
| |
• two recovered lignin
fractions with distinctive molecular weight |
|
