The Effect of Various Concentrations of Tetra-n-butylammonium Fluoride on the Dissociation Enthalpy of Gas Hydrates

Abstract

Semiclathrate hydrate formers such as tetra-n-butylammonium bromide (TBAB), chloride (TBAC) and fluoride (TBAF) are promising compounds that mild the thermodynamic conditions of gas hydrates, considerably. The Clausius-Clapeyron equation is employed in this manuscript to calculate the dissociation enthalpies of methane/carbon dioxide/nitrogen + TBAF semiclathrate hydrates. A 460 cm 3 stirred batch reactor was used to measure the phase equilibria of gas + TBAF semiclathrate hydrates at various concentrations of tetra-nbutylammonium fluoride. The dissociation P-T data were obtained using an isochoric pressuresearch method in the temperature range of 275.15 to 304.7 K and the pressure range of 0.53 to 10.24 MPa at 0.0 -0.4482 mass fraction of TBAF. Investigating the obtained dissociation data showed that the addition of TBAF to the solution increases the amount of dissociation enthalpy of semiclathrate hydrates per mole of the hydrated gas. Increasing the mass fraction of tetra-nbutylammonium fluoride, showed a straight relation with the amount of dissociation enthalpy per mole of hydrated gas.

Investigation of Volume Changes in Carbon Dioxide Hydrate Formation Process

“…In recent years, the potential benefits of gas hydrates have garnered attention, leading to numerous studies in the field [9][10][11][12][13][14][15][16][17][18][19][20][21]. However, due to the high costs and timeconsuming nature of the hydrate formation process, none of the proposed processes utilizing hydrate formation have been implemented on an industrial scale [22][23][24][25][26][27].…”

Selective CO2 Capture from CO2/N2 Gas Mixtures Utilizing Tetrabutylammonium Fluoride Hydrates

“…Typically, the size of the captured ionic species exceeds that of a single large cage of sI (5 12 6 2 ) or sII (5 12 6 4 ) hydrates, necessitating the partial breaking of cages to accommodate the larger ions. Due to ionic interactions between the captured species in confined cages and the incorporated counterions within the hydrate lattice, some ionic semi-clathrate hydrates exhibit exceptional thermodynamic stability, facilitating the capture of gaseous guest molecules under higher-temperature and lower-pressure conditions [26,27]. This property underscores their potential utility in gas storage and separation applications.…”