Low Carbon Economy, 2013, 4, 125-128
http://dx.doi.org/10.4236/lce.2013.43013 Published Online September 2013 (http://www.scirp.org/journal/lce) 125
Improved Carbon Dioxide Capture Using Nanostructured
Ceramic Membranes
Ngozi Claribelle Nwogu, Edward Gobina, Mohammed Nasir Kajama
Centre for Process Integration and Membrane Technology, School of Engineering, Robert Gordon University, Aberdeen, UK.
Email: n.c.nwogu@rgu.ac.uk, e.gobina@rgu.ac.uk, m.n.kajama@rgu.ac.uk
Received August 8th, 2013; revised September 5th, 2013; accepted September 13th, 2013
Copyright © 2013 Ngozi Claribelle Nwogu et al. This is an open access article distributed under the Creative Commons Attribution
License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
ABSTRACT
A nanoporous-structured tubular hybrid inorganic membrane capable of stripping carbon dioxide from flue gas stream
was designed and tested at laboratory scale to improve compliance with various environmental regulations to cushion
the effect of global warming. Single gas separation experiments using silica modified ceramic membrane were carried
out to investigate individual gas permeation behaviors at different pressures and membrane efficiency after a dip coat-
ing method. Four gases: Nitrogen (N2), Carbon dioxide (CO2), Oxygen (O2) and Methane (CH4) were used. Plots of
flow rate versus pressure were generated. Results show that the gas flow rate increases with pressu re drop. However at
above a pressure of 4 bars, the flow rate of CO2 was much higher than the other gases, indicating dominance of a more
selective absorptiv e type transport mechanism.
Keywords: Ceramic Membrane; Carbon Dioxide Capture; Permeability; Selectivity; Gas Transport Mechanisms
1. Introduction
About one third of the overall CO2 emission globally
comes from energy creation. Its decrease and manage-
ment are vitally critical and they are important factors to
ease global warming [1]. The position of CO2 in global
warming is a present-day ecological concern and needs
urgent attention in the provision of techno logies that will
curtail the emission of CO2 [2]. CO2 removal from flue
gas stream recorded the success with conventional tech-
nology like absorption using glycol, amine and methanol
under low temperature, the process with hot potassium
carbonate, the reaction with calcium oxide and the use of
polymer membrane. These processes employ low tem-
perature resulting in energy losses due to high tempera-
ture recuperation as well as cooling of the gas stream [3].
Owing to the burning desire to abate global warming
especially at the rate of CO2 emission and its concentra-
tion in the atmosphere through flue gases today, inor-
ganic ceramic membrane with distinct characteristics
should be a key issue. Cost effective, energy-saving, high
chemical resistance, cheap materials are needed in the
development of membrane module for manufacturing
purposes. Porous inorganic membrane conquers some
rather than all of the in-built limitations. They can toler-
ate higher temperature and basically limit the connection
between selectivity and permeability. If properly design-
ing the pore size and its distribution decides its selectiv-
ity while the volume fraction porosity regulates and es-
tablishes permeability [3]. Porous inorganic membrane
also shows exceptional evidence of physical and chemi-
cal properties, including unresponsiveness to sarcastic
environment, stability under high temperature, homoge-
neous pore structure and reasonable fluxes [4]. Some
membranes today have been used for decades in CO2
capture, but, because the membrane is used for natural
gas at very high pressure, they are unsuitable for CO2
capture from flue gases. D esign and fabr ication of por ous
ceramic membrane consist of several layers of different
materials namely: Aluminium oxide (Al2O3), Titanium
Oxide (TiO2), Zirconium Oxide (ZrO2), Silicon dioxide
(SiO2), Silicon carbide, Zeolite or a mixture of two mate-
rials applied on an underlying porous stainless steel, α-
alumina, γ-alumina, zirconium, zeolite supports [5]. The
manner in which gas molecules flow across the mem-
brane referred to permeation mechanism is a significant
fact in membrane technology. This flow is generally in-
fluenced by three factors: the gas properties, morphology
of the membrane and the material used for membrane
design. Consequently a hybrid material made from ce-
ramics membrane has been well thought out by means of
Nanotechnology. The technology is eco-friendly, eco-
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