Download Pyrolysis

Studies of the Catalytic Conversions of Bio-Oils
Obtained by Pyrolytic Decomposition of NonEdible Biomaterials
Ferenc Lónyi
Institute of Materials and Environmental Chemistry
Research Centre for Natural Sciences
Hungarian Academy of Sciences
Biomass conversion
Biomass
- Diversity
- Seasonal and
disseminated
occurrence
Produces
- vegetable oil
- algae oil
- energy plants
Wastes
- lignocellulosic
- communal
- industrial
- animal
by-products
Conversion
Product
- Near to the location
of biomass generation
- Using the best conversion
technology (economy and
product requirement)
- Locally used energy
(heat or electric)
- Transportable energy
- Intermediates and
chemicals
Biological
- aerobic and anaerobic
fermentation
- enzymatic hydrolysis
Thermal
- combustion
- gasification
- Pyrolysis
(CO2 negative)
Chemical (catalytic)
- transesterification of
oils
- hydrorefining of oils
- processing the
products of other
conversions, e.g.
gasification of
pyrolysis oil to
H2/CO mixture
Liquid fuel
- biodiesel
- ”green” diesel
- FT fuel
- lower alcohols
Pipeline gas
- bio-methane
Electric energy
- fuel cell
- Gas turbine/generator
- Gas engine/generator
Pyrolysis
Char
(~35 wt%)
Pyrolysis gas
(~65 wt%)
Biomass
(e.g. Meat and Bone Meal)
Pyrolysis (~450 – 500 0C)
~85 %-a
condensable
Pyrolysis oil
Reforming is needed !
Not suitable as fuel:
- relatively low energy density
- chemical instability
- corrosivity
- immiscible with conventional fuels
- environmentally hazardous
emission (e.g. NOx)
Composition of pyrolysis oils
Pyrolysis oil of plant origin
Pyrolysis oil of animal origin *
(e.g. from agricultural and forestry residues)
(e.g. from meat and bone meal (MBM))
C, wt%:
60
H, wt%
7
O, wt%
32
N, wt%
1
----------------------------------------Density (kg/dm3):
1.12
Heating value (MJ/kg)
21.3
C, wt%:
74
H, wt%
12
O, wt%
5
N, wt%
9
----------------------------------------Density (kg/dm3):
0.97
Heating value (MJ/kg)
36.5
(Zhang et al., Bioresource Technology 96 (2005) 545
Reforming:
- Catalytic steam reforming to H2/CO mixture
- Catalytic cracking and decarboxylation
- Catalytic esterification
*
Reforming:
- Catalytic steam reforming to H2/CO mixture
- Hydrotreating (heteroatom removal)
- ~20 million tons of animal by-products in the EU 27 countries
- environmentally dangerous waste (microbiological re- and trans-contamination)
- incineration is not favored (fly ash, emission of furans, dioxins and NOx) → pyrolysis
Catalytic steam reforming of pyrolysis oils
CxHyNvOz + xH2O → xCO + (y/2+x-z)H2 + (v/2)N2
[1]
CO + H2O  CO2 + H2
[2]
[1] highly endotherm
[2] slightly exotherm
Products: H2,CO,CO2,N2, (CH4)
Catalytic steam reforming of pyrolysis oil obtained from MBM
TOS d, XC.e,
T a, WHSV b,
c
S/C
Catalyst 0
wt%
h
h-1
C
97.9
7
5
8 (0.8)
750
Ni/K/
>99
35
5
γ-Al2O3 f 750 4 (0.4)
M-1 f
M-2 f
M-2 g
a
H2
N2
CO
CH4
CO2
Product distribution
[%]
55-60
10-15
5-10
3-5
15-20
750
750
700
700
700
700
700
700
18 (0.8)
9 (0.4)
9 (0.4)
9 (0.8)
4.5 (0.4)
9 (0.8)
4.5 (0.4)
4.5 (0.4)
5
5
5
5
5
5
5
3
13
19
24
11
16
12
18
23
94.0
>99
>99
>99
>99
>99
>99
>99
Reaction temperature (the dolomite guard bed was kept always at 800°C).
Weight hourly space velocity based on the weight of the Ni-catalyst, not
including the weight of the cordierite support
(the values in parenthesis are the WHSV for the dolomite guard bed).
c Steam to carbon molar ratio of the feed.
d Time on stream.
e Carbon conversion.
f Catalyst was pre-reduced in H at 500°C.
2
g The catalyst was used without pre-reduction.
b
Catalytic hydrotreating of pyrolysis oils
CxHyNvOz + nH2 → CxH2x+2 + zH2O + vNH3
(heteroatom removal
via HDO and HDN)
Unattractive process for pyrolysis oils of plant origin:
- high H2 demand due to the high oxygen content (>30 wt%)
- useless H2O is formed as by-product
Feasible process for pyrolysis oils of animal origin:
- relatively low H2 demand
- valuable NH3 is formed as by-product
Pyrolysis oil from MBM
Hydrocarbon fuel
+ H2
catalyst
N-compounds:
aliphatic nitriles,
amines and amides
+ NH3
(+H2O)
Catalytic hydrodenitrogenation (HDN) of propyl-amine model
compound (preliminary experiment)
Konverzió, Hozam,
mol%
Yield, mol%
Conversion,
100
Ni2P/silicagel,
WHSV=
1 1h
h-1-1,, p=
30bar
bar
Ni2P/Szilikagél,
WHSV=
p= 30
Conversion
Konverzió
80
Ammónia
Ammonia
60
Propán
Propane
DPA
40
20
TPA
Szelektivitás,
mol%
mol%
Selectivity,
100
0
80
Ammónia
Ammonia
60
Propán
Propane
40
DPA
20
TPA
0
200
250
300
Hõmérséklet,o°C
Temperature,
C
350
400