Kinetics of (TBAF + CO2) semi-clathrate hydrate formation in the presence and absence of SDS

Abstract

In this communication, the impacts of adding SDS (sodium dodecyl sulfate), TBAF (tetra-n-butylammonium fluoride) and the mixture of SDS ? TBAF on the main kinetic parameters of CO 2 hydrate formation (induction time, the quantity and rate of gas uptake, and storage capacity) were investigated. The tests were performed under stirring conditions at T = 5°C and P = 3.8 MPa in a 169 cm 3 batch reactor. The results show that adding SDS with a concentration of 400 ppm, TBAF with a concentration of 1-5 wt%, and the mixture of SDS ? TBAF, would increase the storage capacity of CO 2 hydrate and the quantity of gas uptake, and decrease the induction time of hydrate formation process. The addition of 5 wt% of TBAF and 400 ppm of SDS would increase the CO 2 hydrate storage capacity by 86.1% and 81.6%, respectively, compared to pure water. Investigation of the impact of SDS, TBAF and their mixture on the rate of gas uptake indicates that the mixture of SDS ? TBAF does not have a significant effect on the rate of gas uptake during hydrate formation process.Keywords Semi-clathrate hydrate Á Gas hydrate Á Kinetics Á CO 2 Á SDS Á TBAF List of symbols P Pressure R Universal gas constant T Temperature V Volume of the gas phase Z Compressibility factor Subscripts 0 Conditions of the cell at time t = 0 i Counter t Time w Water

Optimization of determination of CO2 gas hydrates surface tension in the presence of non-ionic surfactants and TBAC

“…Assuming the classical nucleation theory, in a supersaturated solution, the nucleation rate can be obtained using Equation 1.…”

“…Nowadays, emission of carbon dioxide released from fossil fuel combustion, is one of the most important reasons for global warming. Therefore, new ways to reduce emissions of carbon dioxide are under development [1][2][3]. In addition, because of useful and practical aspects of the gas hydrate phenomenon, the necessity of further researches in this field is clarified.…”

“…In addition, because of useful and practical aspects of the gas hydrate phenomenon, the necessity of further researches in this field is clarified. Since a few decades ago, the presence of large amounts of natural gas has been proven which stored in gaseous hydrates in the ocean's bed and the poles [1,[4][5][6].…”

Investigation of the kinetics of formation of Clatrit-like dual hydrates TBAC in the presence of CTAB

“…In the above equation, the storage capacity is calculated in terms of the standard volume of carbon dioxide gas to the volume of hydrate gas. In equation (6), pressure, temperature and global constant of gases are considered in standard conditions. In this equation, VH is the volume of hydrate obtained.…”

“…In this method, carbon dioxide gas is injected at a depth below 400 m and it is trapped by solubilization in water and, due to low temperature and high pressure, deep water carbon dioxide is converted into hydrate at 500 to 900 m above sea level. In this study, the effect of additives (nanoparticles and surfactants) on thermodynamics and kinetics of carbon dioxide hydrate formation is studied and investigated [4][5][6][7].…”