Direct_Liquefaction_of_Biocoals_UniS

Direct Liquefaction of Biocoals as a
Sustainable Route to Second-Generation
Biofuels
Martin Trautmann, Swen Lang, Armin Löwe, Yvonne Traa
Institute of Chemical Technology, University of Stuttgart, Germany
INSTITUTE OF
CHEMICAL TECHNOLOGY
Production of Second-Generation Biofuels
First-generation biofuels, such as ethanol and biodiesel, are made from
sugars or vegetable oils. Second-generation biofuels or advanced biofuels
are made from lignocellulosic biomass or woody crops, agricultural residues or
waste, and are thus less interfering with food supplies and biodiversity.
2
M. Trautmann, A. Löwe, Y. Traa, Green Chem. 16 (2014) 3710.
Direct Coal Liquefaction
2.5
Gasoline
H / C molar ratio
2
Diesel
1.5
1
Synthesis
gas
Coal
0.5
0
1
10
100
1000
Average carbon number
3
Y. Traa, Chem. Commun. 46 (2010) 2175.
10000
Direct Biocoal Liquefaction
4
M. Trautmann, A. Löwe, Y. Traa, Green Chem. 16 (2014) 3710-3714.
Hydrothermal Carbonization of Biomass
• The patented CarboREN technology
from SunCoal Industries homogenizes
biomass to biocoal, which is then dried.
• Using this process, damp biomass with
20–75% water content and a low heating
value is converted to biocoal which has
similar characteristics as fossil coal.
• The CarboREN technology requires
only a minimal amount of energy (7% of
the energy of the produced biocoal) and
is designed in modular units to be
constructed according to customer
needs.
• A wide variety of
materials can be used.
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www.suncoal.de
organic
waste
Outline
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1.
Introduction
2.
Direct Coal Liquefaction in Practice
3.
Results and Discussion
4.
Conclusions and Outlook
http://www.pecj.or.jp/japanese/overseas/conference/pdf/conference04-14.pdf
Shenhua: Direct Coal Liquefaction
 Two
ebullated bed reactors utilising a proprietary
dispersed superfine (nanosized) disposable Fe catalyst
(GelCat) prepared from iron sulfate.
Fixed-bed in-line hydrotreater with Ni-Mo/Al2O3 catalyst.
Feedstock: Bituminous fossil coal.
Reaction conditions: 400 to 460 °C, 17 MPa hydrogen.
July 2011: 12 times of coal injection completed
10,670 operating hours
products:
550,000 t diesel
247,500 t naphtha
7
99,000 t LPG
Simplified Scheme of Direct Coal Liquefaction
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Y. Traa, Chem. Commun. 46 (2010) 2175.
Experimental Setup
Technical data:
Parr MiniBench Top Reactor 4570
Reactor volume: 250 ml
Maximum pressure: 34.5 MPa
Maximum temperature: 773 K
Typical reaction conditions:
T = 623-673 K, pH2,cold = 10 MPa, mtetralin/mmaf coal = 1, reaction time 1 h
pH2, hot = 18-21 MPa.
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Definitions of Direct Coal Liquefaction
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Oil:
Primary liquefaction products which are soluble in
n-pentane (C5-Cn hydrocarbons).
Gas phase:
Organic (C1-C4 hydrocarbons) and inorganic gases
from liquefaction (H2O, NH3, H2S).
Residue:
Unconverted coal.
Asphaltenes:
Further liquefaction products soluble in benzene,
but insoluble in n-pentane.
Preasphaltenes:
Further liquefaction products soluble in pyridine,
but insoluble in benzene.
Coal conversion:
Only oil and gas phase are considered as
converted mass (related to the maf = moistureand ash-free coal).
Results of Direct Biocoal Liquefaction
11
M. Trautmann, S. Lang, Y. Traa, revised version submitted for publication in Fuel.
Quality of the Biooils
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M. Trautmann, S. Lang, Y. Traa, revised version submitted for publication in Fuel.
Biopetroleum?
Standard:
Biomass
Biooil after
„biopetroleum“ liquefaction oil pyrolysis and HDO
Our
biooil
H/C molar
ratio
> 1.5
1.20
1.5
1.32
HHV / MJ
kg-1
> 40.0
38.3
35.2
40.2
Oxygen
content /
wt.-%
< 6.0
10.0
15.1
4.6
HHV = Higher Heating Value: Amount of heated released during combustion.
C. Wang, J. Pan, J. Li, Z. Yang, Bioresource Technol., 99 (2008) 2778.
13
M. Trautmann, A. Löwe, Y. Traa, Green Chem. 16 (2014) 3710.
Simplified Scheme of Direct Coal Liquefaction
14
Y. Traa, Chem. Commun. 46 (2010) 2175.
Considerations for the Second Stage
 Hydrotreating of the oils using hydrogen and typical
catalysts active for hydrodeoxygenation (HDO).
 Co-processing in Fluid Catalytic Cracking Units.
 Selective ring opening of aromatic rings to diesel fuel.
⇒ Tailoring of the second stage
for the envisaged application
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Greener Alternatives for Hydrogen Production
Natural gas (CH4) or mixtures of CH4 and H2 can be used as
hydrogenation gas.
 Liquefaction of brown coal with
NaOH/MeOH at 300°C + 13 MPa;
MeOH, CaO, FeS at 400°C + 4 MPa.
 Liquefaction in CO/H2O: CO + H2O ⇔ CO2 + H2.
 Hydrogen can be produced by water electrolysis using
excess energy from wind or sun.
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 Hydrothermal gasification: Wet biomass is gasified at
temperatures up to 873 K yielding H2 + CO2 . A pilot
plant has already shown to be feasible by producing up
to 83 vol.-% H2 in the product at a high thermal
efficiency.
Conclusions and Outlook
 Direct
liquefaction of biocoals produced by hydrothermal
carbonization from green waste is possible.
 Biooils thus produced are a good starting point for further
upgrading to tailored fuel products.
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 The carbon footprint is reduced by using the produced
biooils.
However,
further
investigations
and
investment are necessary:
i. Valuable hydrogen is consumed to
produce water from oxygen in the
biomass: Green hydrogen production
necessary.
ii. Biooil yields and catalysts have to be
improved.
iii. Biooil upgrading has to be developed.
iv. …
THE END!!!
THANK YOU FOR YOUR
ATTENTION!!!
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