Sorbent materials for the cleaning of sewage biogas
in high temperature fuel cell plants
Davide Papurello1, Andrea Lanzini1, Federico Smeacetto2, Massimo Santarelli11, Politecnico di Torino – DENERG, Corso Duca degli Abruzzi, 24, 10129, Turin, Italy.2, Politecnico di Torino – DISAT, Corso Duca degli Abruzzi, 24, 10129, Turin, Italy.
6 - 9 novembre 2013
Politecnico di Torino
2Politecnico di Torino
Summary:
1. SOFCOM mission overview
2. Biogas from SMAT (WWTPs)
3. Trace compounds detection
4. Sorbent material apparatus
5. Experimental investigation on cleaning system – sorbent
materials (effect of biogas water content)
6. Conclusions and future works
Politecnico di Torino
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SOFCOM is an applied research project devoted to demonstrate the technical
feasibility, the efficiency and environmental advantages of CCHP plants based on
SOFC fed by different typologies of biogenous primary fuels (locally produced) also
integrated by a process for the CO2 separation from the anode exhaust gases.
SOFCOM layout: Demo plant
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Air blower
Air pre-heater
Air CHP
Reformer
SOFC
Cleaning system
Oxy-combustor
Cooling CO2 separation
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Biogas from SMAT – waste water treatment plant
Greatest waste water treatment plant in Italy,
serving 2.2 millions equivalent inhabitants in Turin
metropolitan area (26000 m3/h).
Waste water treatment area: 4 parallel lines: biological “tertiary” treatment with nitrogen and phosphorus removal
Sludge treatment line: pre-dewatering, anaerobic digestion, post-dewatering, drying. Treats over 6000 m3/day of sludge (2%tss)
In absence of oxygen anaerobic microorganisms
turn organic substances of sludge into biogas, a mix
of methane (60-65%) and carbon dioxide (35-40%).
> 6 digesters each 12000 m3, 17-20 day mean residence time;
> 33000 Nm3/day biogas (2010)
SMAT Castiglione Torinese WWTP
6Politecnico di Torino
Biogas trace compounds
ContaminantSMAT Analysis
Feb 2012
SMAT Analysis
May 2012
DIGESTOR
CA 3033
DIGESTOR
CA 3033
DIGESTOR
CA 3034
H2S 78,4 148,5 150,6
Total 120 200 220
Alkene % Vol. % Vol % Vol
C2H4 1 1,2 1,4
Total
chlorine compounds (as HCl) 165.1 211.4
Total 165.1 211.4
Siloxanes ppbv ppbv ppbv
1,1,3,3,5,5-esametiltrisilossano <8 <13 <14,9
decametilciclopentasilossano D5 89.1 277 202
decametiltetrasilossano L4 <8 <13 <14,9
dodecametilpentasilossano L5 <8 <13 <14,9
esametilciclotrisilossano D3 11.4 157 187
esametildisilossano L2 <8 13.7 <14,9
ottametilciclotetrasilossano D4 71.8 253 129
Total 172.3 839.7 553.4
1,2-dichloroethylene (cis) 69.9 N/A N/A
1,2-dichloroethylene (trans) 0.6 N/A N/A
1,2-dichloropropane 2.5 N/A N/A
chloroform 0.7 N/A N/A
chloromethane <0.13 N/A N/A
vinyl chloride <0.119 N/A N/A
dibromochloromethane <0.0811 N/A N/A
dichlorodifluoromethane <0.114 N/A N/A
dioxane 2.8 N/A N/A
hexachlorobutadiene <0.13 N/A N/A
dichloromethane 8.8 N/A N/A
tetrachloroethylene 76.3 N/A N/A
trichloroethylene 11.2 N/A N/A
trichlorofluoromethane <0.155 N/A N/A
Total 172.9 N/A N/A
Chlorine compounds: essentially HCl
(100-400 ppbv)
Siloxane compounds: essentially D4-
D5 (70-400 ppbv)
Sulfur compounds: essentially
H2S (70-180 ppmv)
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H2S
Chlorine compounds:
Siloxane compounds
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Sorbent material apparatus for the sulfur compound removal
CH4/CO2
+
H2S
+
H2O
Blank line
Filter line
PDMS
filter
Heated
trap
HPR 20
MS
Filter
The experimental set-up adopted for the
sorbent material test with simulated biogas
(CH4/CO2 = 1.5), H2S at 30.72 ppm(v) and
demineralized water at 7.28% vol.
9Politecnico di Torino
Experimental investigation on cleaning system – sorbent materials
Sorbent materialApparent density
(kg m-3)
Relative density
(kg m-3)
Grain
dimension
s (µµµµm)
Note
Activated carbon,
RST3 Norit200-600 2100 100-180
Zinc oxide,
Actisorb S2 ZnO Clariant 1090 100-180
Activated carbon,
Carb-OX Air dep520 1650 100-180
The best performance are achieved with low
fraction of oxygen and water – manufacturer
SEM 10000x SEM 2000x
C, Fe, CuZn, O
10Politecnico di Torino
Experimental investigation on cleaning system – effect of biogas water content
0
10
20
30
40
50
60
70
80
90
100
0 200 400 600 800 1000 1200 1400 1600 1800
C/Co (%)
Time (s)
RST3 - H2O 7.28%
ZnO - H2O 7.28%
Carb-ox - H2O 7.28%
0
10
20
30
40
50
60
70
80
90
100
0 200 400 600 800 1000 1200 1400 1600 1800
C/Co (%)
Time (s)
RST3
ZnO
Carb-ox
11Politecnico di Torino
3 sorbent materials were tested for the H2S removal. (Biogas)
Figure depicts the removal performance as the ratio between the outlet
concentration (C) and the inlet concentration (C0) of the filter cartridge.
The best performance are achieved by ZnO and RST3 activated carbon for the sulfur
removal. Carb-ox activated carbon decreases the filer performance around 9% in dry
conditions. At stationary conditions this material removes only 30% whereas the
other two sorbents 60%.
Under wet conditions the filter performance decrease for RST3 and ZnO around 36%
and 28% respectively, whereas in case of Carb-ox they improve of +17%.
Conclusions
12Politecnico di Torino
Further works on the pollutants removal is needed, especially considering chlorines
(HCl, C2Cl4) and siloxane (D4) compounds effect and the contemporary presence of
water.
Future works
At the moment we are testing the same set-up apparatus with:
• Single effect of H2S on RST3, ZnO and air-dep sorbent material plus biogas water
effect;
• Single effect of HCl on RST3, ZnO and air-dep sorbent material plus biogas water
effect;
• Double effect of H2S + HCl on RST3, ZnO and air-dep sorbent material plus biogas
water effect…
13Politecnico di Torino
References
www.polito.it/sofcom/
Papurello, D, et al. Monitoring of volatile compound emissions during dry
anaerobic digestion of the Organic Fraction of Municipal Solid Waste by
Proton Transfer Reaction Time-of-Flight Mass Spectrometry. Bioresource
Technology 126, 254–265
Papurello, D, et al. Biogas from dry anaerobic digestion of the organic
fraction of municipal solid waste: production, cleaning and direct use in a
Solid Oxide Fuel Cell. Waste Management (Under revision)
Papurello, D., Lanzini, L., Santarelli, M., Leone, P., 2013. Solid Oxide Fuel Cell
energy production from biogas – impact of contaminants (COS, C2H4) on fuel
cell performance. ATI 2013.
Papurello, D., Schuhfried, E., Lanzini, A., Romano, A., Cappellin, L., Märk, T.D.,
Silvestri, S., Biasioli, F., 2013. Influence of co-vapors on biogas filtration for fuel
cells monitored with PTR-MS (Proton Transfer-Reaction Mass Spectrometry).
Fuel Processing Technology 2014; 118: 133-140.(0378-3820/$ -
http://dx.doi.org/10.1016/j.fuproc.2013.08.011)
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Thanks for the attention
Davide Papurello – [email protected] – 3402351692
Politecnico di Torino – DENERG, Corso Duca degli Abruzzi, 24, 10129,
Turin, Italy.