Adsorption characteristics of the silica gels as adsorbent for gasoline vapors removal

Adsorption characteristics of three kinds of silica gels named GA, GB and GC as adsorbents for cyclohexane removal at at five initial concentrations (2.1 g.m(-3), 5.4 g.m(-3), 9.2 g.m(-3), 16.3 g.m(-3), and 21.2 g.m(-3)) were systematically investigated. The experimental results showed that GA has the rich microporous and mesoporous distributions, and the larger surface area and microporous volume than GB and GC. It can be clearly seen that the order of the adsorption rate of adsorbents on the silica gels samples is GA, GB and GC. Due to the suitable pore distribution in the region of micropore and mesopore (1-4 nm), GA exhibits the comparable breakthrough adsorption capacities with GB and GC for a given initial concentration. Moreover, the experimental data were fitted to the Langmuir and Freundlich models, respectively. The Langmuir isotherms correlated with the experimental data presented a better fitting than Freundlich model. Taken together, it is expected that GA silica gel would be a promising adsorbent for the removal of gasoline vapors from gas streams.