“Improved Carbon- Based

Sorbent for CO2

Capture”Maha Yusuf1, Habib Nasir1, Wei-Yi-Chen2, Arshad Hussein1, Mohammad

Mujahid1

» Need to improve CO2 capture process; one possible route is to develop new carbon-based

sorbents

» Need to find new routes for disposing captured CO2 ; CO2 fixation on carbonaceous

compounds is the first step of many CO2 utilization processes

» Nano-Carbons have a large surface area for CO2 capture and functionalization – Procedures

for manipulating and functionalizing Nano-Carbons (such as graphene, CNT, GO and GOF) have

been well-established

» CO2 capture on these carbon materials have not been systematically investigated!

Introduction Improved Carbon-Based Sorbent for CO2 Capture

Nano-Graphite Nano-Graphene Nano-Graphene Oxide Nano-Graphene oxide Framework Functionalized Nano-Graphene Oxide, its frameworks CO2 Capture Capacity

Key Concepts

Synthesis of Nano-Graphene Oxide

• Single - Layer Nano-Graphene Oxide (NGO) sheets are prepared from graphite flakes, 450 m by a ‘new method’ which is further modification of the ‘Modified Hummer’s method’, using sonication during the oxidation process and KMnO4 as the only oxidant which was followed by freeze-drying of the product.

4

graphite has an interlayer spacing of 0.335 nm

oxidationby modifiedHummers'method

H2SO4

NaNO3

KMnO4

exfoliation

ultra sonication

graphite oxide has an interlayer spacing about 0.7 nm. It contains three major oxygen functional groups: epoxides, phenolic and carboxylic acids

single-layer graphene oxide (GO) platelets. Nano-sized GO contains a rich population of oxygen functional groups that have emerged as the building blocks for many technologies

Figure 2: Burress et al. (2010) showed that a) boronic ester and b) GOF formation. Idealized graphene oxide framework (GOF) materials proposed in this study are formed of layers of graphene oxide connected by benzenediboronic acid pillars. The resultant GOF can be oxidized and then grafted with an amine (just like GO mentioned in Figure 2) that serves as a potentially potent CO2-chemisorption adsorbent.

Synthesis of Nano-Graphene Oxide Frame-work Preparation of Nano-Graphene Oxide Framework (NGOF) from ‘Methanol Solvothermal synthesis’ using freeze-dried

GO prepared from Asbury Micro 450 as the base material The linker used was: B14DBA (Benzene 1,4-Diboronic Acid)

i. BET with N2 gas• BET Surface Area• Pore Volume

ii. SEMiii. EDAX - SEMiv. XRD v. BET with CO2 gas

RESULTS

BET with N2 Results

Asbury Micro 450 Asbury 4827 Freeze-Dried GO

BET Surface Area m2/g 11.6650 232.0207 102.2141

Adsorption Average Pore Size Width/ Ao 18.9948 18.7232 18.7233

Quantity Adsorbed (cm3/g STP) at relative

pressure of 0.2503.5812 70.2121 30.9314

XRD Spectra of Nano - Graphite

XRD Spectra of Freeze-dried GO

XRD Spectra of Nano-Graphene Oxide Framework

SEM Images

Micro 450 Micro 850

SEM Images

Freeze-Dried GO

Thermally Exfoilated Graphene

SEM Images

Graphene-Oxide Framework

BET with CO2 gas

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.50

5

10

15

20

25

f(x) = 36.5952065911459 x + 4.58372015079742R² = 0.984626749993261

Freeze-Dried GO

Relative Pressure (p/po)

Qua

ntity

Ads

orbe

d (c

m3/

g ST

P)

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.50

0.010.020.030.040.050.060.070.080.09

0.1

f(x) = 0.0343528608783989 x + 0.0658755539223476R² = 0.109990603430659

Asbury Micro 450

Relative Pressure (p/po)

Qua

ntity

Ads

orbe

d (c

m3/

g ST

P)

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.50

2

4

6

8

10

12

f(x) = 8.42112450151645 x + 7.11433165215779R² = 0.425744906286923

Nano-graphene Oxide Framework

Relative pressure (p/po)

Qua

ntity

Ads

orbe

d (c

m3/

g ST

P)

CO2 Adsorption Capacity Data• Calculations: Density of CO2 at 1 atm and 0 C = 1.977 kg/m3Note: these are calculated at p/po = 0.45

Samples Mg CO2 Adsorbed per gram of sample

Nano-Graphite 1.977 kg/m3 * 0.090 cm3/g sample = 0.17793 mg CO2 adsorbed/g sample

Nano-Graphene Oxide 1.977 kg/m3 * 21 cm3/g sample = 41.517 mg CO2 adsorbed/g sample

Nano-Graphene Oxide Framework

1.977 kg/m3 * 9.74 cm3/g sample = 19.255 mg CO2 adsorbed/g sample

Conclusions

Higher O/C ratio for Nano-Graphene Oxide (NGO) with new method of combining oxidation with sonication at the same time

BET Surface area of Asbury 4827 (nano-graphite) highest – possibility of making advanced CO2 sorbent using this as the base material

CO2 Adsorption capacity of single-layer nano-graphene oxide sheets is the highest even higher than the highest reported by the Chinese Group of the functionalized graphitic oxide with 50 wt% EDA = 46.55 mg CO2/g sample!

Goal of CO2 capture CCS technology Improved Gasification Efficiency Waste (including CO2) Utilization Soil fertility New Avenue of CO2 Utilization Possible CO2 Adsorbent in Industry replacing liquid amine CO2 capture membranes

Applications of the Project

Burress, J.W., Gadipelli, S., Ford, J., Simmons, J.M., Zhou, W., Yildirim., T. Graphene oxide framework materials: theoretical predictions and experimental results. Angew. Chem. Int. Ed. 2010, 49, 8902-8904.

Chateauneuf, J.E., Zhang, J., Foote, J., Brink, J., Perkovic, M.W., Photochemical Fixation of Supercritical Carbon Dioxide: the Production of a Carboxylic Acid from a Polyaromatic Hydrocarbon, Advances in Environmental Research, 2002, 6, 487-493.

Stankovich, S., Dikin, D.A., Dommett, G.H.B., Kohlhaas, K.M., Zimney, E.J., Stach, E.A., Piner, R.D., Nguyen, S.T., Ruoff, R.S., Graphene-based composite materials. Nature. 2006, 442, 282-286.

LITERATURE SURVEY/ REFERENCES

Thank You!!!!

Maha Yusuf

CEMP 2013 (NUST)