While large-scale coal-to-liquid (CTL) and gas-to-liquid (GTL) processes have
been commercialized for decades (e.g., Sasol and Shell plants) (Dimitriou et al.
2018), this is not the case of BTL processes. Only a few plants have been built to date
on pilot and demonstration scale:
– In the late nineties, Choren started operating a 1MWth BTL plant in Freiberg,
Germany, which is not working anymore (Dimitriou et al. 2018).
– NSE Biofuels Oy operated a 12MWth (656 t/yr of fuels) BTL demonstration
plant in Finland from 2009 to 2011, based on a circulating fluidized bed (CFB)
gasifier designed by Foster Wheeler (Neste Oil Corporation n.d.).
– In 2010, five French partners and Uhde launched BioTfueL with two pilot plants
currently on operation in France: a biomass torrefaction unit in Venette and an
entrained flow gasification and Fischer-Tropsch (FT) synthesis plant near Dunkirk (Dimitriou et al. 2018).
– The Karlsruhe Institute of Technology (KIT) bioliq pilot plant with a capacity of
1 t/day has been in operation since 2014 using a process similar to the Topsoe
TIGAS process.
Biomass-to-liquid (BTL) is a multistep process which consists of the following
phases:
1. Reception, storage, handling, and preparation
2. Biomass gasification
3. Gas cleaning and conditioning
4. Fuel synthesis
1.5.2 Reception, Storage, Handling, and Preparation
Biomass, which is mainly transported by road, after storage is conveyed to a
magnetic separator (to separate iron parts and impurities) and then screened to
keep particle sizes within appropriate limits.
Biomass drying can be performed either by hot air (rotary dryer) or steam
(superheated steam dryer). Air rotary dryers are the most common (WA A 1998),
while superheated steam dryers (SSD) are less common but are safer with respect to
fire hazards. Fuel synthesis processes (such as FT synthesis) generate significant
amounts of steam, which can be reused to dry biomass (at the temperature of 200
C
and pressure of 12 bar) (Dimitriou et al. 2018).
A grinder (hammer mill) has to be placed after the dryer in case the fuel will be
used in an entrained flow gasifier, to reduce the wood chips size to 1mm (Van der
Drift et al. 2004; Swanson et al. 2010). If a circulating fluidized bed gasifier is used,
this is capable of handling a wider variety of biomass particle sizes (Bridgwater and
Maniatis 2014), so no grinding would be required.
1 Biofuels: Types and Process Overview
19
been commercialized for decades (e.g., Sasol and Shell plants) (Dimitriou et al.
2018), this is not the case of BTL processes. Only a few plants have been built to date
on pilot and demonstration scale:
– In the late nineties, Choren started operating a 1MWth BTL plant in Freiberg,
Germany, which is not working anymore (Dimitriou et al. 2018).
– NSE Biofuels Oy operated a 12MWth (656 t/yr of fuels) BTL demonstration
plant in Finland from 2009 to 2011, based on a circulating fluidized bed (CFB)
gasifier designed by Foster Wheeler (Neste Oil Corporation n.d.).
– In 2010, five French partners and Uhde launched BioTfueL with two pilot plants
currently on operation in France: a biomass torrefaction unit in Venette and an
entrained flow gasification and Fischer-Tropsch (FT) synthesis plant near Dunkirk (Dimitriou et al. 2018).
– The Karlsruhe Institute of Technology (KIT) bioliq pilot plant with a capacity of
1 t/day has been in operation since 2014 using a process similar to the Topsoe
TIGAS process.
Biomass-to-liquid (BTL) is a multistep process which consists of the following
phases:
1. Reception, storage, handling, and preparation
2. Biomass gasification
3. Gas cleaning and conditioning
4. Fuel synthesis
1.5.2 Reception, Storage, Handling, and Preparation
Biomass, which is mainly transported by road, after storage is conveyed to a
magnetic separator (to separate iron parts and impurities) and then screened to
keep particle sizes within appropriate limits.
Biomass drying can be performed either by hot air (rotary dryer) or steam
(superheated steam dryer). Air rotary dryers are the most common (WA A 1998),
while superheated steam dryers (SSD) are less common but are safer with respect to
fire hazards. Fuel synthesis processes (such as FT synthesis) generate significant
amounts of steam, which can be reused to dry biomass (at the temperature of 200
C
and pressure of 12 bar) (Dimitriou et al. 2018).
A grinder (hammer mill) has to be placed after the dryer in case the fuel will be
used in an entrained flow gasifier, to reduce the wood chips size to 1mm (Van der
Drift et al. 2004; Swanson et al. 2010). If a circulating fluidized bed gasifier is used,
this is capable of handling a wider variety of biomass particle sizes (Bridgwater and
Maniatis 2014), so no grinding would be required.
1 Biofuels: Types and Process Overview
19