Volatile organic compounds adsorption using different types of adsorbent

Abstract

Adsorbents were synthesized from coconut shell, coal and coke by pyrolysis followed by chemical activation
process. These synthesized materials were used as adsorbents in adsorption test to determine the amount of
volatile organic compounds (VOCs) namely, 2-Hydroxyethyl methacrylate (HEMA), Octamethylcyclotetrasiloxane
and Alkanes standard solution (C8-C20). The adsorption capacities of both synthesized adsorbents and
commercial grade adsorbents (Carbotrap™ B and Carbotrap™ C) were also compared. It was found that
adsorbent A402, which was produced from coconut shell, activated with 40% (wt.) potassium hydroxide and
at activating temperature of 800°C for 1 hr, could adsorb higher amount of both HEMA and
Octamethylcyclotetrasiloxane than other synthesized adsorbents. The maximum adsorption capacity of adsorbent A402 in adsorbing HEMA and Octamethylcyclotetrasiloxane were 77.87% and 50.82%
respectively. These adsorption capabilities were 79.73% and 70.07% of the adsorption capacity of the
commercial adsorbent Carbotrap™ B respectively. All three types of the synthesized adsorbent (A402,
C302, C402) showed the capability to adsorb alkanes standard solution through the range of C8-C20 .
However, their adsorption capacities were high in a specific range of C10-C11. The result from the isotherm
plot was indicated that surface adsorption of synthesized adsorbent was isotherm type I while the surface
adsorption of commercial adsorbent was isotherm type III.