To determine the suitable operating conditions for hydrate-based CO2 separation process from a fuel gas mixture, hydrate nucleation and growth kinetics of simulated (39.2 mol % CO2/H2 mixture) in presence tetra-n-butyl ammonium bromide (TBAB) are investigated. The experiments were conducted at TBAB concentration range 0.14−1.00 %, temperature 275.15−282.45 K, driving force 1.00−4.50 MPa, gas/liquid phase ratio 0.86−6.47, time 15−120 min. It is found that addition not only shortens induction...

The equilibrium hydrate formation conditions for the gas mixture of CO2 and H2 with tetrabutyl ammonium bromide (TBAB) are measured. data show that TBAB can reduce pressure as an additive mole fraction (0.14, 0.21, 0.29, 0.50, 1.00, 2.67) %. experiments were carried out in temperature range (274.05 to 288.55) K (0.25 7.26) MPa. + is remarkably lower than at same decreases increase concentration TBAB. In addition, avoid pure hydrate, which there no or H2, above mixture, from (0.14 % also

The gas production behavior from methane hydrate in porous sediment by injecting the brine with salinity of 0−24 wt % and temperature −1 to 130 °C was investigated a one-dimensional experimental apparatus. results show that process consists three periods: free production, dissociation, general reservoir production. dissociation accompanies decrease injection (NaCl solution), duration is shortened increase salinity. With hot brine, instantaneous rate also increases However, while NaCl...

Quaternary salts can form semi-clathrate hydrates, caging gas molecules in the empty small cages, which have potential for separation of mixtures, such as simulated flue [CO2 (17 mol %)/N2 mixtures]. To enhance CO2 from CO2/N2 binary three quaternary salts, tetra-n-butylammonium bromide (TBAB), tetra-n-butylphosphonium (TBPB), and nitrate (TBANO3), are investigated at different operating conditions by a one-stage hydrate process. The results indicate that induction time each salt system be...

The behavior of hydrate formation in porous sediment has been widely studied because its importance the investigation reservoirs and drilling natural gas hydrate. However, it is difficult to understand nucleation growth mechanism on surface nanopores media by experimental numerical simulation methods. In this work, molecular dynamics simulations CH4 presence clay are carried out. configurations microstructure properties analyzed for systems containing one H2O layer (System A), three layers...

Molecular structural information on a Chinese Xishan bituminous coal was obtained using elemental analysis, high resolution transmission electron microscope (HRTEM), laser desorption time-of-flight mass spectrometry (LD-TOF MS), solid state 13C nuclear magnetic resonance (NMR), and X-ray photoelectron spectroscopy (XPS) techniques. The size distribution of aromatic structures were determined by HRTEM, providing 300 base skeletons for model. Aliphatic side chains heteroatoms introduced into...

To investigate the detailed mechanisms for brown coal oxidation at high temperatures, a ReaxFF reactive forcefield was used to perform series of molecular dynamics simulations from 1000 K 2500 K. Analyses indicated that chemical system tend be more with increasing temperature. It found process primarily initiates hydrogen abstraction reactions by O2 and related oxygenated radicals phenolic hydroxyl groups, methyl especially carboxyl groups in lower temperature form peroxygen species, or...

The combustion characteristics of both pure propane hydrates and the mixtures quartz sands were investigated by experiments. flame propagation, appearance, burning time temperature in different hydrate layers studied. For combustion, initial falls “premixed” category. propagates very rapidly, mainly as a result burnt gas expansion. finally self-extinguishes with some proportion remaining unburned. hydrate-sand mixture takes form many tiny discontinuous flames appearing disappearing at...

This work presents the thermodynamic study of separating CH4 and CO2 from simulated landfill gas (LFG) [CO2 (0.45) + (0.55)] based on hydrate crystallization in presence tetra-n-butyl ammonium bromide (TBAB), tetrahydrofuran (THF), dimethyl sulfoxide (DMSO), their mixtures. The mole fractions TBAB, THF, DMSO aqueous solutions were fixed at 0.0234, 0.0556, 0.0165, respectively. equilibrium formation conditions measured by T-cycle method temperature range (274.15 to 294.95) K pressure ranges...

Abstract The depressurization method is one of the most promising methods for exploitation hydrate reservoirs and has been conducted in several field tests. In this work, production behaviors methane sand sediments by different strategies were comparatively investigated using a cubic simulator (CHS) with capacity 5.832 L. experimental conditions are based on parameters South China Sea. results indicate that dissociation rate related to pressure heat conduction between surroundings. Some form...

The phase equilibrium data of cyclopentane (CP) + methane hydrates in brine water with NaCl mass fractions w = 0, 0.035, 0.070, and 0.100 were measured the temperature range (284.4 to 301.3) K using a visual high-pressure apparatus. dissociation enthalpies CP hot determined via Clausius−Clapeyron equation based on these data. effect help gas salinity hydrate was studied, respectively. Liquid forms small-molecule at region much higher than quadruple point pure hydrate. Methane partially...

Methane (CH4) hydrate dissociation and the mechanism by depressurisation are investigated molecular dynamics (MD) simulation. The decomposition processes studied 'vacuum removal method' normal method. It is found that promoted depressurisation. quasi-liquid layer formed in surface layer. driving force of to be controlled concentration gradient between H2O molecules inner clathrates collapse gradually, decomposes Relative our previous MD simulation results, this study shows rate slower than...