Effects of As-Produced and Amine-Functionalized Multi-Wall Carbon Nanotubes on Carbon Dioxide Hydrate Formation

In an attempt to mitigate carbon dioxide emissions, new technologies are being proposed that can aid in greenhouse gas sequestration. One such technology involves trapping carbon dioxide in hydrate form. To optimize this process, it is of interest to investigate how the hydrate system behaves in the presence of promoting agents. In this work, the effect of asproduced and amine-functionalized multi-wall carbon nanotubes (MWNTs) on carbon dioxide dissolution and hydrate growth rates was studied. For either type of the MWNTs, the effect on saturation values and dissolution rates was negligible. Under lower concentrations, it was found that both forms of MWNTs enhanced growth, with the functionalized MWNTs performing slightly better. Under higher concentrations, both forms of MWNTs decreased growth rates, because the initial nucleation event was more pronounced and led to heat- and mass-transfer limitations.