Development of Bentonite Based Solid Support for C02 Removal

It is well known that the main contributor of greenhouse gases is C02. The
increasing C02 concentration in the atmosphere has resulted in a lot of
research finding ways to slow down this trend. Established traditional
technologies to capture C02 use aqueous amines. However there are
drawbacks to this method thus much attention has been given to solid
support. Bentonite clays have high cation exchange capacity, swelling
capacity, high surface areas, and consequential strong adsorption/absorption
capacities. Moreover, Bentonite clays are cheap and have been proved as a
suitable candidate in removing organic compounds such as benzene form
water. Thus, the objective of this research is to develop bentonite clay into
becoming an adsorbent for C02. Bentonite clays on its own are not effective
adsorbents for organic compounds thus modifications to the surface
chemistry can be done to enhance its capabilities by changing the surface
form hydrophilic to organophilic (hydrophobic). This type of clays called
as organoclays can be synthesized by exchanging the metallic cations on the
surface of bentonite clays such as Mi+, k + and Na + with organic cations.
Organic cations such as Tetramethylammonium (TMA) and
Hexadecyltrimethylammonium (HDTMA) have been used to synthesize
organoclays and have used successfully to treat water. Thus intercalation of
bentonite clay with N-cetyltrimethylammonium bromide (CTMB) cations
was done. The RAMAN spectroscopy results showed that the CTMB
cations were successfully intercalated into the clays. Results from
Transmission Electron Microscopy (TEM) showed that the organo
bentonites had increased its basal spacing from 9.72 to 14.03 A. COz
Adsorption were conducted and results showed the organo bentonite had
the ability to adsorb C02 but at relatively low amounts.