biochar production by pyrolysis of lignocellulosic biomass in a conical spouted bed reactor
DESCRIPTION
eman ta zabal zazu. Universidad del País Vasco. Euskal Herriko Unibertsitatea. BIOCHAR PRODUCTION BY PYROLYSIS OF LIGNOCELLULOSIC BIOMASS IN A CONICAL SPOUTED BED REACTOR. Maider Amutio, Gartzen Lopez, Maite Artetxe, Astrid Barona, Martin Olazar - PowerPoint PPT PresentationTRANSCRIPT
BIOCHAR PRODUCTION BY PYROLYSIS OF
LIGNOCELLULOSIC BIOMASS IN A CONICAL SPOUTED BED
REACTORMaider Amutio, Gartzen Lopez, Maite Artetxe, Astrid
Barona, Martin Olazar
Chemical Engineering Department, University of the Basque Country UPV/EHU
PO Box 644 – 48080 Bilbao. Spain. [email protected]
Euskal HerrikoUnibertsitatea
Universidad
del País Vasco
eman ta zabal zazu
Introduction
Biomasso Alternative to fossil fuels → the only renewable source of fixed
carbon.o Biomass → Liquid, solid and gaseous fuels + heat and power.
Pyrolysiso One of the technologies with the best industrial perspectives.o Bio-oil as biorefinery feedstock (decouple bio-oil production).
Biomass flash pyrolysiso Maximum liquid production:
o Products: Bio-oil = 60-80 wt%. Alternative fuel or source of chemicals
Gas = 10-20 wt%. Supply energy to the pyrolysis plant
Char = 15-25 wt%. Fuel, activated carbon or soil amendment.
Chemical Engineering Department. University of the Basque CountryPO Box 644 – 48080 Bilbao. www.ehu.es/cpwv
T ~ 500 ºCVery high heating rates Short gas residence time Rapid char removal
Minimize secondary cracking reactions
Introduction
Vacuum pyrolysiso Improvement of the operational capacity of this
technology:• Reduction of the mass flow-rate of the inert gas→ reduction
in the energy requirement to heat the gas to the reaction temperature.
• Simplification of the bio-oil condensation and collection section.
o Advantages:• Reduction of secondary cracking reactions: rapid
desorption and extraction of the volatile products from the reaction environment.
• Improvement in char quality.
Reactorso Biomass flash pyrolysis: Fluidized bed reactors.o Biomass vacuum pyrolysis: Vacuum moving bed.
Chemical Engineering Department. University of the Basque CountryPO Box 644 – 48080 Bilbao. www.ehu.es/cpwv
Conical spouted bed reactor (CSBR)
Advantages:
o Simple design
o Less pressure drop than fluid
beds
o Different particle diameters
and irregular materials
o Great versatility in gas flow
(low residence time)
o Good heat and mass transfer
o Allows continuous extraction
of char
Introduction
Chemical Engineering Department. University of the Basque CountryPO Box 644 – 48080 Bilbao. www.ehu.es/cpwv
Fountain
Spout
Annulus
Conical spouted bed reactor (CSBR)
Advantages:
o Simple design
o Less pressure drop than fluid
beds
o Different particle diameters
and irregular materials
o Great versatility in gas flow
(low residence time)
o Good heat and mass transfer
o Allows continuous extraction
of char
Introduction
Chemical Engineering Department. University of the Basque CountryPO Box 644 – 48080 Bilbao. www.ehu.es/cpwv
Annulus
Pyrolysis bench scale plant
Experimental
Chemical Engineering Department. University of the Basque CountryPO Box 644 – 48080 Bilbao. www.ehu.es/cpwv
Raw material: Pinewood (pinus insignis) sawdust
Experimental conditionso Temperature: 400 and 500 ºCo Pressure: 0.25 and 1 atmo Biomass: 0.1-2 mm, 25 kg/mino Bed: 20 kg sand (1-2 mm)o Inert gas flow rate (liters/s)
o On line product analysis: GC, µGC and GC/MS
Experimental
Chemical Engineering Department. University of the Basque CountryPO Box 644 – 48080 Bilbao. www.ehu.es/cpwv
Pressure (atm)
Temperature (ºC) 0.25 1
400 3.2 11.5
500 3 10.5
Experimental
Chemical Engineering Department. University of the Basque CountryPO Box 644 – 48080 Bilbao. www.ehu.es/cpwv
Experimental
Chemical Engineering Department. University of the Basque CountryPO Box 644 – 48080 Bilbao. www.ehu.es/cpwv
Fractions: gas, bio-oil and char. Yields in wet basis
o High liquid yields: 77 % wt at 500 ºC and 0.25 atm o P ↓ → bio-oil ↑, char ↓ (reduction of secondary
reactions)o P ↓ → Desorption and diffusion of the volatiles in the
biomass particle ↑ Residence time of volatiles in the particle ↓
Results: product yields
0
10
20
30
40
50
60
70
80
Gas Bio-oil Char
Yie
ld (%
wt)
0.25 atm
1 atm
0
10
20
30
40
50
60
70
80
Gas Bio-oil Char
Yie
ld (%
wt)
0.25 atm
1 atm
Chemical Engineering Department. University of the Basque CountryPO Box 644 – 48080 Bilbao. www.ehu.es/cpwv
400 ºC 500 ºC
Mainly made up of CO2 and CO
P ↓ → CO2 ↑, T ↑→ CO2 ↓
Results: gas composition
Chemical Engineering Department. University of the Basque CountryPO Box 644 – 48080 Bilbao. www.ehu.es/cpwv
Compound 400 ºC 500 ºC
0.25 atm 1 atm 0.25 atm 1 atm CO2 5.08 4.36 3.47 3.27 CO 2.49 2.42 3.34 3.38 H2 0.01 - 0.01 0.00 CH4 0.06 0.05 0.32 0.36 ethylene 0.02 0.01 0.10 0.09 ethane 0.01 0.01 0.04 0.06 propylene 0.02 0.01 0.11 0.07 propane 0.01 0.01 0.02 0.05 2-methyl-1-propene 0.00 0.01 0.04 0.02 2-butene - - 0.03 0.01 unidentified - 0.00 0.04 0.01 Gas 7.7 6.9 7.5 7.3
Water is the main compound ~ 25 %wt
Phenols: guaiacols (methoxy phenols), catechols (benzenediols) and alkyl-phenols.
Saccharides: levoglucosan yield increases at lower pressures.
Pressure has different influence at 400 ºC and 500 ºC
P ↓→ Bio-oil is composed of heavier compounds
Results: bio-oil composition
Compound 400 ºC 500 ºC
0.25 atm 1 atm 0.25 atm 1 atm acids 3.32 2.49 2.40 2.73 aldehydes 2.41 2.44 2.37 1.93 alcohols 2.26 1.75 1.56 2.00 ketones 6.79 5.87 5.81 6.37 phenols 16.35 15.57 18.75 16.49 alkyl phenols 3.04 2.12 1.18 1.80 catechols 2.94 3.15 10.09 7.16 guaiacols 10.37 9.94 7.48 7.53 furans 2.58 3.30 1.63 3.32 saccharides 3.55 5.26 6.26 4.46 levoglucosane 0.22 0.52 3.27 2.78 others 0.14 0.09 0.03 0.06 unidentified 11.95 10.70 13.41 12.61 water 23.00 23.33 24.98 25.36 Bio-oil 73.01 71.23 75.33 77.19
Chemical Engineering Department. University of the Basque CountryPO Box 644 – 48080 Bilbao. www.ehu.es/cpwv
P ↓→ Carbon content increases slightly (less water and more heavier and less oxygenated compounds) → Calorific value ↑
Operating at subatmospheric pressure slightly improves bio-oil’s valorization prospects as fuel. However, its calorific value is low, so it has to be subjected to treatments.
Chemical Engineering Department. University of the Basque CountryPO Box 644 – 48080 Bilbao. www.ehu.es/cpwv
Properties 400 ºC 500 ºC
0.25 atm 1 atm 0.25 atm 1 atm Ultimate analysis (% wt) carbon 43.9 42.7 42.9 41.7 hydrogen 8.1 8.1 8.0 8.1 nitrogen 0.1 0.1 0.2 0.2 oxygen 47.9 49.1 48.9 50.0 Water content (% wt) 34.5 35.8 35.3 36.7 Calorific value (MJ/ kg) 15.8 15.2 15.4 14.6
Results: bio-oil properties
T ↑→ Carbon content and calorific value ↑ P ↓ → Carbon content and calorific value ↑ at 400 ºC but ↓ at 500
ºC. Carbon content > 75 % . Low ash content LHV higher than the ones of soft coal (29 MJ/kg) and lignite (20
MJ/kg)
Chemical Engineering Department. University of the Basque CountryPO Box 644 – 48080 Bilbao. www.ehu.es/cpwv
400 ºC 500 ºC 0.25 atm 1 atm 0.25 atm 1 atm Ultimate analysis (wt%)
Carbon 79.7 75.0 84.5 85.2 Hydrogen 3.4 3.8 2.8 3.0 Nitrogen 0.01 0.2 0.1 0.1 Oxygen 16.9 21.0 12.6 11.8
Proximate analysis (wt%) Volatile matter 27.6 37.6 24.0 23.5 Fixed carbon 69.8 60.2 72.8 73.6
Ash 2.6 2.2 3.2 2.9
LHV (MJ kg-1) 26.8 21.6 28.2 30.4
Results: char characterization
P ↓ → BET surface area ↑, pore diameter ↓ 500 ºC, 0.25 atm → mesopores of 100 Å and micropores of 19
Å are formed Devolatilization and diffusion of volatiles through the biomass
particle ↑ Blocking of the pores due to carbonaceous material deposits ↓ 400 ºC 500 ºC
0.25 atm 1 atm 0.25 atm 1 atm Surface characteristics
BET surface (m2 g-1) 5.1 1.9 79.2 16.2 Average pore diameter (Å) 464.3 472.1 53.2 453.5
Chemical Engineering Department. University of the Basque CountryPO Box 644 – 48080 Bilbao. www.ehu.es/cpwv
500 ºC, 0.25 atm 500 ºC, 1atm
Results: char characterization
Conclusions
Chemical Engineering Department. University of the Basque CountryPO Box 644 – 48080 Bilbao. www.ehu.es/cpwv
Conical spouted bed reactor: suitable technology to perform vacuum biomass flash pyrolysis.
High bio-oil yields: 77 wt% at 500 ºC and 0.25 atm.
Vacuum influence on product yields and properties: o Low influence on fraction yields, but bio-oil
yield slightly increases.o Bio-oil: heavier compounds (phenols,
levoglucosan, etc.), less water. Calorific value ↑ o Char: Improvement of surface characteristics.
Vacuum increases process viability: Inert gas flow rate is lower → Less energy is required to heat the carrier gas and the condensation of the product stream is easier.
BIOCHAR PRODUCTION BY PYROLYSIS OF
LIGNOCELLULOSIC BIOMASS IN A CONICAL SPOUTED BED
REACTORMaider Amutio, Gartzen Lopez, Maite Artetxe, Astrid
Barona, Martin Olazar
Chemical Engineering Department, University of the Basque Country UPV/EHU
PO Box 644 – 48080 Bilbao. Spain. [email protected]
Euskal HerrikoUnibertsitatea
Universidad
del País Vasco
eman ta zabal zazu