CO2 capture enhancement by forming tetra-n-butyl ammonium bromide semiclathrate in graphite nanofluids

In this work, CO2 capture was experimentally investigated by forming tetra-n-butyl ammonium bromide (TBAB) semiclathrate in a new system of TBAB + graphite nanofluids. The experiments were carried out at 3.5 MPa and 277.15 K. Compared to the TBAB solution and the TBAB + sodium dodecyl sulphate (SDS) solution, it was found that the system of TBAB + graphite nanofluids was preferable for CO2 capture, and 0.2 wt.% graphite nanoparticles (GNP) was an optimal concentration for the enhancement of hydrate growth in TBAB + graphite nanofluids. At this GNP concentration, CO2 consumption gained at 0.29 mol% TBAB is greater than that acquired at 0.62 and 2.57 mol% TBAB. CO2 consumption obtained in TBAB + graphite nanofluids is larger than other systems containing GNP. Moreover, the morphologies of TBAB + CO2 semiclathrate formed in TBAB solution, TBAB + SDS solution, and TBAB + graphite nanofluids were presented, and the mechanism of CO2 capture using TBAB semiclathrate formation in graphite nanofluids was presented. Therefore, it is an efficient way to capture CO2 by forming TBAB semiclathrate in graphite nanofluids.