The Effect of the Number of Fibers in Hollow Fiber Membrane Modules for NOx Absorption
Corresponding email: sutrasno@che.ui.ac.id
Published at : 21 Apr 2020
Volume : IJtech
Vol 11, No 2 (2020)
DOI : https://doi.org/10.14716/ijtech.v11i2.3616
Kartohardjono, S., Rizky, M.S., Karamah, E.F., Lau, W., 2020. The Effect of the Number of Fibers in Hollow Fiber Membrane Modules for NOx Absorption. International Journal of Technology. Volume 11(2), pp. 269-277
| Sutrasno Kartohardjono | Department of Chemical Engineering, Faculty of Engineering, Universitas Indonesia, Kampus UI Depok, Depok 16424, Indonesia |
| Mohamad Sofwan Rizky | Department of Chemical Engineering, Faculty of Engineering, Universitas Indonesia, Kampus UI Depok, Depok 16424, Indonesia |
| Eva Fathul Karamah | Department of Chemical Engineering, Faculty of Engineering, Universitas Indonesia, Kampus UI Depok, Depok 16424, Indonesia |
| Woei-Jye Lau | Advanced Membrane Technology Research Centre, Universiti Teknologi Malaysia, 81310 Skudai, Johor, Malaysia |
As a type of gas that contributes to
air pollution, nitrogen oxide (NOx) has harmful effects on humans
and the environment. Among several types of NOx, nitric oxide (NO)
and nitrogen dioxide (NO2) are most commonly found in air. The
utilization of membranes as reactors is a system that combines chemical
reactions with the separation process through membranes to increase the
conversion of the reaction. This study investigated the absorption process by utilizing a hollow fiber membrane module
(polysulfone) as a bubble reactor with H2O2 (0.5 wt.%)
and HNO3 (0.5M) as the absorbent. NOx feed gas was flown into the
tube side of the membrane; the shell side was filled with static H2O2
and HNO3 and the shell input and the tube output flow were closed to
create gas bubbles. The experimental results showed that the absorption
efficiency increased, but the mass transfer coefficient and flux decreased as
the number of fibers in the membrane module increased at the same feed gas flow
rate. The NOx loading is relatively constant as the amount of fiber
in the membrane module increased at the same feed gas flow rate. The
experimental results also showed that the mass transfer coefficient, flux, and
NOx loading increased with increasing feed gas flow rate, but the
absorption efficiency decreased when using the same number of fibers in the
membrane module. The maximum NOx absorption efficiency achieved in
this study was 94.6% at the feed gas flow rate of 0.1 L/min, using a membrane
module with 48 fibers.
Absorption efficiency; Hollow fiber; Mass transfer coefficient; NOx loading
Currently, atmospheric pollution is a significant problem across the globe; apart from SO2, the most dangerous and toxic gas is NOx (nitrogen oxide). NOx is produced from the reaction between nitrogen (N) and oxygen (O) during the combustion process at high temperatures. Among several types of NOx, such as N2O, nitrogen monoxide (NO), N2O3, nitrogen dioxide (NO2), N2O4, and N2O5, NO and NO2 are the ones most often found in atmospheric air, with NO comprising >90% of the total amount of gas (Kumar et al., 2015). Furthermore, 49% of NOx comes from motor vehicles, 27% comes from the activities of the electricity generation industry, and 19% comes from household activities. NOx has also been reported to have the ability to cause acid rain, form fog fumes, decrease water quality, destroy ecosystems, and contribute to global warming (Choi et al., 2014; Gao et al., 2018; Kartohardjono et al., 2019a; Sun et al., 2019). In addition, NOx is also having harmful effect on the human being (Kartohardjono et al., 2019b).
The reduction of NOx in exhaust gases, such as those from boilers and the nitric acid (HNO3) industry, is currently attracting much attention due to increasingly stringent environmental regulations; for example, the annual average quality standard for NO2 in ambient air is set at 0.053 ppm (Indonesia, 1999). Several technologies have been pioneered for this purpose, including Selective Catalytic Reduction, Selective Non-Catalytic Reduction, adsorption, and absorption using column contactors (Kartohardjono et al., 2019b). Similarly, the absorption of NOx using membrane technology has also been developed; in this type of system, the contactors offer several advantages: a continuous process that is easy to operate, low energy consumption, easy scale-up, low separation costs, and the ability to produce high-quality products (Kartohardjono et al., 2017)
Hollow fiber membrane contactors have been widely used
as gas-liquid contactors due to the large ratio between their surface area for
contact and the equipment volume (Lipnizki and Field, 2001). Furthermore, gas
absorption through the membrane contactor also the integrates
separation and absorption processes to exploit the benefits of both. Moreover,
the hollow fiber membrane module has two different spaces for each fluid,
shell, and tube. The in-flowing liquid provides selective absorption to certain
gas species, while the porous membrane acts as the contacting interface between
the liquid and gas phases, allowing the unidirectional transport of gas into
the liquid. For example, the gas component to be removed is absorbed into the
solution when the gas stream contacts with the liquid (Wang and Yu, 2017). The hollow fiber
membrane module also provides a
large ratio of surface area to volume, which is very beneficial for gas-liquid
contact (Anggraini et al., 2019). Additionally, the mass transfer
between phases that occurs in membrane modules is driven by differences in the
concentration of the inter-phase components and pressure drops.
In contrast, the use of membranes as reactors involves
the combination of chemical reactions with the separation process through
membranes with the usual intention of increasing the conversion of the
reaction. A bubble reactor is a type of reactor that is in two phases of gas
and liquid; it is a cylindrical vessel with a gas distributor (sparger) at the
bottom. The fluid in the gas phase flows into the vessel and, in the process,
gas bubbles are formed and move through the liquid inside the vessel. The
advantages of this type of reactor include high mass transfer rates, high
density, and low operating and maintenance costs (Shaikh and Al-Dahhan, 2013). Bubble reactors are
widely applied in chemical, petrochemical, biochemical, metallurgical, and
materials industries.
A number of studies have investigated the use of membranes as additional
units in processes involving bubble reactors or columns. Xia et al. (2013) immersed a hollow fiber membrane module in a liquid
cylindrical bubble column reactor to test the hydrodynamic effect induced by an
installed sparger. Moreover, Adewuyi et al. (2014)
investigated if a membrane could remove the remaining moisture from the results
of NOx gas absorption using Na2S2O8
solvents from a bubble reactor made from glass. The present study was conducted
to examine the utilization of hollow fiber membrane modules to reduce NOx
from gas mixtures using a mixture of hydrogen peroxide (H2O2)
and HNO3 as
the absorbent. It was expected that the fibers in the membrane module would
increase the contact area between NOx and the absorbent solution to
enhance the NOx absorption.
This study utilized hollow fiber membrane modules to absorb NOx
using a mixture of HNO3 0.5M
and H2O2
0.5% w/t as the absorbent. The feed gas flow rate and the number of
membrane fibers were the main variables used in this study. The aim was to
understand their effects on the overall mass transfer coefficient, flux, absorption
efficiency, and NOx loading. The experimental results showed that
the mass transfer coefficient, flux, and NOx loading increased by
increasing the feed gas flow rate, while the absorption efficiency decreased.
The highest NOx absorption efficiency achieved in this study was
94.6% at the feed gas flow rate of 0.2 L/min with the membrane module with 48
fibers in the contactor. Moreover, the mass transfer coefficient and flux
decreased while the absorption efficiency increased as the number of fibers in
the contactor increased at the same feed gas flow rate. The NOx
loading was relatively constant as the number of fibers in the contactor
increased at the same feed gas flow rate. In this study, the increase in the
efficiency of NOx absorption was insignificant when the amount of
fibers in the membrane module increased from 16 to 42 at the feed gas flow rate
of 0.1 L/min. However, the NOx absorption efficiency decrease was
insignificant if the gas flow rate increased from 0.1 to 0.2 L/min on a
membrane module with 48 fibers. The NOx absorption efficiency
achieved in this study was already high (about 93.8%), even for the membrane
module with the lowest number of fibers (16 fibers) and at the highest feed gas
flow rate (0.2 L/min).
The authors wish to acknowledge that they received financial support for this study
from the PDUPT Project via Directorate of Research and Services Universitas Indonesia
through Contract No. NKB-1665/UN2.R3.1/HKP.05.00/ 2019.
Adewuyi, Y.G., Khan, M.A., Sakyi, N.Y., 2014.
Kinetics and Modeling of the Removal of Nitric Oxide by Aqueous Sodium
Persulfate Simultaneously Activated by Temperature and Fe2+. Industrial & Engineering Chemistry
Research, Volume 53(2), pp. 828–839
Anggraini, I.D.,
Keryanti., Kresnowati, M.T.A.P., Purwadi, R., Noda, R., Watanabe, T., Setiadi,
T., 2019. Bioethanol Production via Syngas Fermentation of Clostridium
Ljungdahlii in a Hollow Fiber Membrane Supported Bioreactor. International
Journal of Technology, Volume 10(3), pp. 481–490
Choi, J., Lee,
K.S., Choi, D.Y., Kim, Y.J., Kim, S.S., 2014. Dry De-NOx Process via
Gas-phase Photochemical Oxidation using an Ultraviolet and Aerosolized H2O/H2O2
Hybrid System. Energy & Fuels, Volume
28(8), pp. 5270–5276
Gao, L., Li, C.,
Lu, P., Zhang, J., Du, X., Li, S., Zeng, G., 2018. Simultaneous Removal of HgO
and NO from Simulated Flue Gas Over Columnar Activated Coke Granules Loaded
with La2O3-CeO2 at Low Temperature. Fuel, Volume 215, pp. 30–39
Indonesia, P.R., 1999.
Peraturan Pemerintah No. 41 Tahun 1999 Tentang: Pengendalian Pencemaran Udara.
(Air Pollution Control No. 41),
pp. 1–34
Kartohardjono, S.,
Darmawan, R., Karyadi, M.F., Saksono, N., 2016. CO2 Absorption
through Super-hydrophobic Hollow Fiber Membrane Contactors. Journal of Environmental Science and
Technology, Volume 9(2), pp. 214–219
Kartohardjono, S.,
Merry, C., Rizky, M.S., Pratita, C.C., 2019a. Nitrogen Oxide Reduction through Absorbent
Solutions Containing Nitric Acid and Hydrogen Peroxide in Hollow Fiber Membrane
Modules. Heliyon, Volume 5(12), pp. 1–10
Kartohardjono, S.,
Paramitha, A., Putri, A.A., Andriant, R., 2017. Effects of Absorbent Flow Rate
on CO2 Absorption through a Super Hydrophobic Hollow Fiber Membrane
Contactor. International Journal of
Technology, Volume 8(8), pp. 1429–1435
Kartohardjono, S.,
Saksono, N., Supramono, D., Prawati, P., 2019b. NO2 Removal from Air
through Super Hydrophobic Hollow Fiber Membrane Contactors. International Journal of Technology, Volume
10(3), pp. 472–480
Kartohardjono, S.,
Shabanindita, S., Harianja, M., Dixon, A.O., Yuliusman, Y., Saksono, N. 2019c. N2O
Absorption through Super Hydrophobic Hollow Fiber Membrane Contactor. Environmental Progress and Sustainable
Energy, Volume 38(2), pp. 362–366
Kumar, A.P.M.,
Sreekumar, J.S., Mohanan, P., 2015. The Effect of Cordierite/Pt Catalyst on the
NOx Reduction in a Diesel and Jatropha Bio-diesel Operated Single
Cylinder Engine. Journal of Environmental
Chemical Engineering, Volume 3(2), pp. 1125–1136
Lipnizki, F.,
Field, R.W., 2001. Mass Transfer Performance for Hollow Fibre Modules with Shell-side
Axial Feed Flow: Using an Engineering Approach to Develop a Framework. Journal of Membrane Science, Volume 193(2),
pp. 195–208
Shaikh, A., Al-Dahhan,
M., 2013. Scale-up of Bubble Column Reactors: A Review of Current State-of-the-Art.
Industrial & Engineering Chemistry
Research, Volume 52(24), pp. 8091–8108
Sun, P., Cheng,
X., Wang, Z., Lai, Y., Ma, C., Chang, J., 2019. NOx Reduction by CO Over
ASC Catalysts in a Simulated Rotary Reactor: Effect of Reaction Conditions. Journal of the Energy Institute, Volume 92(3),
pp. 488–501
Wang, Y., Yu, X.,
2017. Removal of NO Research in a Polypropylene Hollow Fiber Membrane
Contactor. In: The 6th
International Conference on Energy, Environment and Sustainable Development
(ICEESD 2017)
Wang, Z., Zhang,
Y., Tan, Z., Li, Q., 2018. A Wet Process for Oxidation-Absorption of Nitric
Oxide by Persulfate/Calcium Peroxide. Chemical
Engineering Journal, Volume 350, pp. 767–775
Xia,
L., Law, A.W.-K., Fane, A.G., 2013. Hydrodynamic Effects of Air Sparging on Hollow
Fiber Membranes in a Bubble Column Reactor. Water
research, Volume 47(11), pp. 3762–3772