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Co-production of Diesel and Synthetic Natural Gas from the Olive Oil Industry Waste
Javier Barrientos KTH – Chemical Technology
Outline
1. Setting the scene
2. The fuel production process
3. The Fischer-Tropsch synthesis - Diesel
production
4. Methanation – Synthetic natural gas (SNG)
production
2
1. Setting the scene
Branches
Olive tree
Olives Olive oil
Seeds Pomace
3
1. Setting the scene Olive production uses a significant part of the available land in Mediterranean countries
Algeria Greece
Italy
Morocco
Portugal
Spain
Syrian Arabic
Republic
Tunisia
Turkey
Harvested area 2010 > 8 000 000 Ha Residues > 14 Mt! 4
Ref: European Commission. Environment. Life among the olives. Good practice in improving environmental performance in the olive oil sector. [Online] 26-01-2010
1. Setting the scene
• Alternative to fossil fuels
• Reduction of greenhouse gas emissions
5
2. The fuel production process
PHYSICAL PRETREATMENT
CHEMICAL PRETREATMENT
FUEL SYNTHESIS Diesel
SNG
Waste
Pellets
Synthesis gas (CO and H2)
6
2. The fuel production process
PHYSICAL PRETREATMENT
Waste
Drying Grinding Mixing Pelletizing
Pellets
7
2. The fuel production process
CHEMICAL PRETREATMENT
Tar removal
CO2 removal
Purification (e.g. H2S removal)
Synthesis
gas
Gasification Pellets
8
2. The fuel production process
FUEL SYNTHESIS
Synthesis
gas
Fischer-Tropsch Methanation
Compression
Liquid
fuels
(diesel)
SNG
9
3. The Fischer-Tropsch Synthesis
𝐶𝑂 + 2𝐻2 → −𝐶𝐻2 −+𝐻2𝑂 (∆𝐻 ° = −165 𝑘𝐽/𝑚𝑜𝑙)
C1-C2 C3-C4 C5-C10 C11-C21 C22+
SNG LPG Gasoline Diesel Wax
𝑇𝑒𝑚𝑝𝑒𝑟𝑎𝑡𝑢𝑟𝑒 ↑ 𝑆𝑒𝑙𝑒𝑐𝑡𝑖𝑣𝑖𝑡𝑦 𝑡𝑜 𝑙𝑜𝑛𝑔 𝑐ℎ𝑎𝑖𝑛 ℎ𝑦𝑑𝑟𝑜𝑐𝑎𝑟𝑏𝑜𝑛𝑠 ↓
𝑃𝑟𝑒𝑠𝑠𝑢𝑟𝑒 ↑ 𝑆𝑒𝑙𝑒𝑐𝑡𝑖𝑣𝑖𝑡𝑦 𝑡𝑜 𝑙𝑜𝑛𝑔 𝑐ℎ𝑎𝑖𝑛 ℎ𝑦𝑑𝑟𝑜𝑐𝑎𝑟𝑏𝑜𝑛𝑠 ↑
10
3. The Fischer-Tropsch Synthesis
0.0 0.2 0.4 0.6 0.8 1.00.0
0.2
0.4
0.6
0.8
1.0
Wei
ght
frac
tio
n
= f(P, T, catalyst)
C1-C2
C3-C4
C5-C10
C11-C21
C22+
It is impossible to only produce hydrocarbons in the carbon number range of C11-C21!
11
3. The Fischer-Tropsch Synthesis
C1-C2
C3-C4
C5-C10
C11-C21
C22+ (wax)
Hydrocracking
Fischer-Tropsch
Diesel production optimization
Diesel
Reforming
Synthesis gas
Diesel is maximized by optimizing the selectivity to C22+ 12
3. The Fischer-Tropsch Synthesis
Reactor optimization
Goal: Isothermal operation
Slurry bed reactor Multitubular fixed
bed reactor
T = 200-250 °C P = 20-40 bar
𝐻𝑜𝑡 𝑠𝑝𝑜𝑡𝑠 𝑆𝑒𝑙𝑒𝑐𝑡𝑖𝑣𝑖𝑡𝑦 𝑡𝑜 𝑙𝑜𝑛𝑔 𝑐ℎ𝑎𝑖𝑛 ℎ𝑦𝑑𝑟𝑜𝑐𝑎𝑟𝑏𝑜𝑛𝑠 ↓↓↓
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3. The Fischer-Tropsch Synthesis
Catalyst optimization Slurry bed reactor
• High activity, selectivity and
stability
• High attrition resistance
Catalyst particle size: 50-100 µm
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3. The Fischer-Tropsch Synthesis
Catalyst optimization Multitubular fixed
bed reactor
• High activity, selectivity and
stability
• Mass transfer
Catalyst particle size: > 1mm
Egg-shell catalyst:
15
16
3. The Fischer-Tropsch Synthesis
0 2 4 6 8 10 120
5
10
15
20
25
30
35Yi
eld
of
CO
to
Hyd
roca
rbo
ns
(NL/
day
per
gra
m o
f ca
taly
st)
Time on Stream (days)
FT conventional conditions:
20 bar synthesis gas
20 bar synthesis gas + 15 bar He
17
3. The Fischer-Tropsch Synthesis
0 200 400 600 800 1000 1200
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
Rela
tive a
ctivity
Sulphur loading (g S/g cat)
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3. The Fischer-Tropsch Synthesis
0
10
20
30
40
50
60
70
80
90
100
SC5+
CO
convers
ion/
Sele
ctivity (
%)
Fresh
10 ppm S
100 ppm S
250 ppm S
1000 ppm S
XCO
SCH4
SC2-C4
Operating conditions: 20 bar, 210 °C and H2/CO=2.1
4. Methanation
𝐶𝑂 + 3𝐻2 → 𝐶𝐻4 +𝐻2𝑂 (∆𝐻 ° = −206 𝑘𝐽/𝑚𝑜𝑙)
0.0 0.2 0.4 0.6 0.8 1.00.0
0.2
0.4
0.6
0.8
1.0W
eigh
t fr
acti
on
= f(P, T, catalyst)
C1-C2
C3-C4
C5-C10
C11-C21
C22+
𝐓 ↑↑ 𝐒𝐞𝐥𝐞𝐜𝐭𝐢𝐯𝐢𝐭𝐲 𝐭𝐨 𝐂𝐇𝟒 ↑↑↑ 19
4. Methanation
𝐓 ↑↑ 𝐒𝐞𝐥𝐞𝐜𝐭𝐢𝐯𝐢𝐭𝐲 𝐭𝐨 𝐂𝐎𝟐 ↑↑↑
𝐶𝑂 + 𝐻2𝑂 → 𝐶𝑂2 +𝐻2 (∆𝐻 ° = −41 𝑘𝐽/𝑚𝑜𝑙)
100 200 300 400 500 600 700 80050
60
70
80
90
100C
O c
onvers
ion (
%)
T (° C)
CO conversion
P = 20 bar
Initial conditions: molar H2/CO = 3
0
20
40
60
80
100
CH4 selectivity
CO2 selectivity
Sele
ctivity (
%)
20
4. Methanation
Reactor/process optimization T = 250-650 °C P = 20-40 bar
650 °C
300 °C
550 °C 450 °C
300 °C 300 °C 300 °C
350 °C
21
4. Methanation
Catalyst optimization Minimize catalyst deactivation!
T=250-350 °C Nickel carbonyl formation T=300-450 °C Carbon formation T=450-650 °C Sintering
Preeminent methanation catalyst: Nickel-based
22
4. Methanation
23
0 2 4 6 8 10 12 14 16 18 20 22 24
0
10
20
30
40
50
60
70
80
90
100
Catalyst 1
Catalyst 2
Catalyst 3
Catalyst 4
Catalyst 5
CO
convers
ion (
%)
Time on stream (h)
Operating conditions: 20 bar, 310 °C and H2/CO=3
4. Methanation
24
200 400 600 800 1000 1200
Am
ou
nt
of
ca
rbo
n (
a.u
.)
T (K)
Isothermal
great!
Acknowledgements
This research has received funding from the European Union Seventh Framework Programme (FP7/2013) under grant agreement n° 308733.
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FFW partners:
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Thank you for your attention
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