M. ZGRZEBNICKI A.GĘSIKIEWICZ-PUCHALSKA R.J. WROBEL
B. MICHALKIEWICZ U. NARKIEWICZ A.W. MORAWSKI
Study of ash removal from activated carbon and its result
on CO2 sorption capacity
Presentation structure:
Introduction
Materials and methods
Experimental
Results
Conclusions
Acknowledgements
Supporting data
PRESENTATION OUTLINE
Introduction
Greenhouse effect
Fig. 1. Solar radiation – primary radiation. Fig. 2. IR radiation - secondary radiation.
http://www.esrl.noaa.gov/gmd/outreach/carbon_toolkit/basics.html
Temperature [°C]
Earth without greenhouse effect -18
Earth with greenhouse effect 15
Tab.1. Temperature on Earth with and without greenhouse effect.
Introduction
2015; 0.87
-0.4
-0.2
0.0
0.2
0.4
0.6
0.8
1.0
1950 1960 1970 1980 1990 2000 2010
DIF
FE
RE
NC
E O
F A
VE
RA
GE
AN
NU
AL
TE
MP
ER
AT
UR
E [°C
]
YEAR
Fig. 3. Changes of carbon dioxide concentration. Fig. 4. Changes of average temperature.
http://www.esrl.noaa.gov/gmd/ccgg/trends/full.html
CO2 and temperature
Introduction
Fig. 5. Carbon Capture and Storage scheme.
http://www.sccs.org.uk/
Carbon Capture and Storage
Introduction
Acivated carbons:
microporous materials,
specific surface area up to 2500 m2/g,
support for noble metals,
cointain mineral matter,
used in purification of water and as
an adsorbent for SO2 or CO2.
Material
containing
carbon
Carbonization
Physical
activation
(CO2, H2O(g))
Chemical
activation
(KOH, K2CO3)
Combined
activation
Materials used for preparation activated carbon:
cherry stones,
wood,
palm shell,
coal,
peat.
Scheme 1. Preparation of activated carbon.
Materials and methods
Methods:
BET,
CO2 uptake,
XPS,
XRF,
XRD.
Materials:
• activated carbon BA11 (delivered by Carbon, Poland),
• 35-38% hydrochloric acid, 65% nitric acid, 40% fluoric acid
(Chempur, Poland).
Fig. 6. Activated carbon BA11.
Experimental
BA11
BA11_HCl
BA11_HNO3
BA11_H2O
BA11_HF
+HCl
+HNO3
+HF
+H2O
(B)(A)
1
2 3
4
5
6
78
Fig. 7. Synthesis apparature: (A) for acid treatment, (B) for
water treatment. 1 – filtering flask, 2 – Buchner funnel, 3 –
beaker, 4 –magnetic stirrer, 5 – condenser, 6 – Soxhlet
apparatus, 7 – round bottom flask, 8 – hot plate.
Scheme 2. Preparation of sorbents.
Results
0.0
2.0
4.0
6.0
8.0
10.0
12.0
Ca Fe Mg Al Si S K
CO
NC
EN
TR
AT
ION
[w
t%]
ELEMENTS
BA11
BA11_HCl
BA11_HNO3
BA11_H2O
BA11_HF
Fig. 8. XRF results of activated carbons.
Results
10 20 30 40
10 20 30 40 50
B
2°
10 20 30 40 50
F
BA11 HCl
10 20 30 40 50
D
BA11 HNO3
10 20 30 40 50
P1
O
20 40
L
BA11-HF
A
H
F
H
HH
H H
Q
Q
Q
Q(BA11)
AF
(BA11_HCl)
(BA11_HNO3)
(BA11_H2O)
(BA11_HF)
50
POSITION 2θ[°]
INT
EN
SIT
Y [
arb.
unit
s]
Fig 10. XRD results. Identified phases:
A – anhydrite, Q – quartz, H – hematite, F
– fluorite.
Fig 9. Mineral matter content.
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
0.00 0.20 0.40 0.60 0.80 1.00 1.20
PS
D [
cm3
g-1
nm
-1]
Pore width [nm]
BA11
BA11_HCl
BA11_HNO3
BA11_H2O
BA11_HF
Results
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
1.0 2.0 3.0 4.0 5.0
PS
D [
cm3g
-1nm
-1]
Pore width[nm]
BA11
BA11_HCl
BA11_HNO3
BA11_H2O
BA11_HF
Sample Vmicro [cm3/g] Vsubmicro [cm3/g] (<0.8 nm)
BA11 0.28 0.10
BA11_HCl 0.29 0.13
BA11_HNO3 0.30 0.14
BA11_H2O 0.30 0.14
BA11_HF 0.27 0.16
Fig. 11. Pore size distribution calculated from
CO2 adsorption/desorption isotherms at 0 °C.
Fig. 12. Pore size distribution calculated from N2
adsorption/desorption isotherms at -196 °C.
Tab. 2. Pore volumes of obtained samples.
Results
180.0
200.0
220.0
240.0
260.0
280.0
300.0
320.0
0.0 0.2 0.4 0.6 0.8 1.0
VO
LU
ME
AD
SO
RB
ED
[cm
3/g
]
RELATIVE PRESSURE P/P0
BA11
BA11_HCl
BA11_HNO3
BA11_H2O
BA11_HF0.0
0.5
1.0
1.5
2.0
2.5
3.0
0.0 0.2 0.4 0.6 0.8 1.0
SO
RP
TIO
N C
APA
CIT
Y [
mm
ol/
g]
RELATIVE PRESSURE P/P0
BA11
BA11_HCl
BA11_HNO3
BA11_H2O
BA11_HF
SampleSBET
[m2/g]
Sorption capacity
[mmol/g]
Vmicro
[cm3/g]
Vsubmicro [cm3/g]
(<0.8 nm)
BA11 967 2.01 0.28 0.10
BA11_HCl 997 2.50 0.29 0.13
BA11_HNO3 1001 2.73 0.30 0.14
BA11_H2O 1024 2.30 0.30 0.14
BA11_HF 960 2.88 0.27 0.16
Fig. 12. N2 adsorption/desorption isotherms at -196 °C.Fig. 13. CO2 adsorption isotherms at 0 °C.
Tab. 3. Results from volumetric methods for obtained samples.
Results
540 538 536 534 532 530 528
inte
nsity [a
rb. u
nits]
biding energy [eV]
experimental
C-O
C=O
COOH
H2O
Fe2O
3
SiO2
CaSO4
backgorund
envelope
Fig. 15. XPS results. Deconvolution of O 1s signal from
BA11 sample.
Fig. 17. XPS results. Composition
of the surface for BA11,
BA11_HCl, BA11_HNO3.
296 294 292 290 288 286 284 282
inte
nsity [a
rb. u
nits]
binding energy [eV]
experimental
graphite
C=O
C-O
COOH
satellite
keto-enolic
background
envelope
Fig. 16. XPS results. Deconvolution of C 1s signal from
BA11 sample.
BA11 BA11_HCl BA11_HNO3
0
20
40
60
80
100
Su
rfa
ce
co
mp
ositio
n [a
tom
ic %
]
O 1s
C 1s
1. Mineral matter behave like a ballast. Its removal leads to increased CO2 sorption
capacity.
2. Mineral matter may block access to pores. Its removal leads to increased specific
surface area and may provide access to additional submicropores crucial for CO2
adsorption.
3. The most effective compounds in removing mineral matter are:
• HCl/HF for removing Fe2O3,
• distilled water for removing CaSO4,
• HF for removing SiO2.
4. CaSO4 should be removed prior to HF treatment due to formation of fluorite.
5. The highest sorption capacity was achieved for activated carbon after HF treatment
(an increase of 44%).
6. Removing mineral matter reveals oxidized surface of the activated carbon.
CONCLUSIONS
The research leading to these results has received funding from the Polish-Norwegian
Research Programme operated by the National Centre for Research and Development
under the Norwegian Financial Mechanism 2009-2014 in the frame of Project Contract
No Pol-Nor/237761/98.
ACKNOWLEDGEMENTS
Improvement of CO2 uptake of activated carbons by treatment
with mineral acids
A. Gęsikiewicz-Puchalska, M. Zgrzebnicki, B. Michalkiewicz, U.
Narkiewicz, A.W. Morawski, R.J. Wrobel, Chemical Engineering
Journal, 309 (1 February 2017) p. 159-171
Thank you for your attention.
SUPPORTING DATA