5 Commercial Aspects of Biomass Deconstruction with Ionic Liquids
109
FEED HANDLING
PRE-TREATMENT
LIGNIN RECOVERY
IL CONDITIONING
Pre-treatment
Reactor
Cellulose Rich Pulp
Slurry
Pump
Filter
Slurry
Pump
Filter
Lignin
Burner
Flash
Vessel
Condenser
Biomass
Lean IL (20% Water)
Rich IL
Water
Pump
Lignin
Lignin
PrecipitaƟon
Vessel
Waste Water
Biomass Feedstock
Biomass Mill
Steam
Diluted IL
Fig. 5.7 Conceptual design of the ionoSolv process
ranging from 120 to 180 °C (depending on the biomass type) for a specific residence
time (~15–60 min).
The temperature and time can be chosen based on the desired product specifications. For example, for bioethanol production obtaining highly delignified celluloserich pulp is key to ensure high sugar yield in the downstream enzymatic hydrolysis
unit. For cellulose material applications, conditions should be optimized to have the
required properties, such as fiber length, density, and tensile strength.
Once the pretreatment reaction is completed, the slurry is sent to a filter to separate
the cellulose-rich pulp (solid) from the IL/water mixture containing the dissolved
lignin (lignin-rich IL). The pulp is then washed thoroughly to ensure the complete
removal of residual IL. Pulp washing on a large-scale system was highlighted as one
of the potential process challenges and will be discussed in more detail in Sect. 5.6.3.
The lignin-rich IL is then sent to the lignin recovery unit where lignin is precipitated
by adding water as an antisolvent. The recovered lignin is filtered and washed with
water to ensure minimal losses of the IL. Lignin is then sent to a boiler where
heat is recovered and used to supply the process energy requirements, as no lignin
valorization is considered at this stage of the process development. The diluted IL
flowing from the lignin recovery unit needs to be re-concentrated before it is recycled
back to the pretreatment reactor. The re-concentration or regeneration of the IL is
expected to be a process-limiting step as water removal is naturally a highly energyintensive process.
109
FEED HANDLING
PRE-TREATMENT
LIGNIN RECOVERY
IL CONDITIONING
Pre-treatment
Reactor
Cellulose Rich Pulp
Slurry
Pump
Filter
Slurry
Pump
Filter
Lignin
Burner
Flash
Vessel
Condenser
Biomass
Lean IL (20% Water)
Rich IL
Water
Pump
Lignin
Lignin
PrecipitaƟon
Vessel
Waste Water
Biomass Feedstock
Biomass Mill
Steam
Diluted IL
Fig. 5.7 Conceptual design of the ionoSolv process
ranging from 120 to 180 °C (depending on the biomass type) for a specific residence
time (~15–60 min).
The temperature and time can be chosen based on the desired product specifications. For example, for bioethanol production obtaining highly delignified celluloserich pulp is key to ensure high sugar yield in the downstream enzymatic hydrolysis
unit. For cellulose material applications, conditions should be optimized to have the
required properties, such as fiber length, density, and tensile strength.
Once the pretreatment reaction is completed, the slurry is sent to a filter to separate
the cellulose-rich pulp (solid) from the IL/water mixture containing the dissolved
lignin (lignin-rich IL). The pulp is then washed thoroughly to ensure the complete
removal of residual IL. Pulp washing on a large-scale system was highlighted as one
of the potential process challenges and will be discussed in more detail in Sect. 5.6.3.
The lignin-rich IL is then sent to the lignin recovery unit where lignin is precipitated
by adding water as an antisolvent. The recovered lignin is filtered and washed with
water to ensure minimal losses of the IL. Lignin is then sent to a boiler where
heat is recovered and used to supply the process energy requirements, as no lignin
valorization is considered at this stage of the process development. The diluted IL
flowing from the lignin recovery unit needs to be re-concentrated before it is recycled
back to the pretreatment reactor. The re-concentration or regeneration of the IL is
expected to be a process-limiting step as water removal is naturally a highly energyintensive process.