Query: propane hydrate formation in batch reactor

title: Experimental study and modeling of the kinetics of gas hydrate formation for acetylene, ethylene, propane and propylene in the presence and absence of SDS
abstract: The kinetics of hydrate formation of the hydrocarbons acetylene, ethylene, propane, and propylene were investigated using a fully stirred batch reactor. In relation to hydrate formation, a kinetic model was used to determine the induction time, the rate of hydrate formation, the apparent hydration rate constant, water to hydrate conversion associated with hydrate growth as well the storage capacity. This was done for all gases investigated in this study. Experiments were performed in the temperature and pressure ranges of (273.7 280.0) K and (0.5 4.12) MPa, respectively. Furthermore, the effect of sodium dodecyl sulfate (SDS) on the gas hydrate formation rate was examined. A substantial growth in the hydrate nucleation rate was observed in the presence of SDS.

title: Clathrate hydrate formation from a hydrocarbon gas mixture: Compositional evolution of formed hydrate during an isobaric semi batch hydrate forming operation
abstract: The clathrate hydrate formation from a model natural gas, i.e. a mixture of methane, ethane, and propane in a 90:7:3molar ratio, under a constant pressure was experimentally investigated, focusing on the compositional evolution of hydrate crystals formed inside a gas bubbling type reactor during each semi batch hydrate forming operation. The experimental system used in this study was specially designed for obtaining several hydrate samples formed at different, arbitrarily selected stages during each hydrate forming operation. Each hydrate sample was analyzed by a gas chromatograph to determine the mole fractions of methane, ethane and propane encaged in the hydrate. These analyses revealed a monotonic increase in the methane fraction and decreases in the ethane and propane fractions during each operation until a quasi steady state was established. Powder X ray diffraction analyses showed that both structure I and structure II crystals were simultaneously formed during the quasi steady period. The compositional evolution of the hydrates formed during the early stages before the quasi steady state was reached deviated from corresponding predictions based on the thermodynamic simulation scheme previously reported. A hypothetical explanation for the discrepancy between the experimental and simulation based results was provided.

title: MODELING OF METHANE AND PROPANE HYDRATE FORMATION KINETICS BASED ON CHEMICAL AFFINITY
abstract: In this study, experimental data on the kinetics of methane and propane hydrate formation at constant volume were collected. The experiments were carried out in a batch reactor under different temperatures and pressures. The chemical anity was used for modeling of the hydrate formation rate in a constant volume process. In this method, the system was considered as a classical thermodynamic or macroscopic view. The results show that this method can predict constant volume experimental data well for both crystals I and II hydrate former.

title: Clathrate Hydrate Formation from a Methane Ethane Propane Mixture in an Unstirred Surfactant Containing System
abstract: This paper describes an experimental study of clathrate hydrate formation from a model natural gas, i.e. a mixture of methane, ethane, and propane in a 90:7:3 molar ratio, in an unstirred gas/liquid system containing a surfactant additive. The specific process of interest in this study is the hydrate formation in a semi batch type reactor charged with a quiescent aqueous phase containing sodium dodecyl sulfate and a well mixed gas phase, to which the above methane ethane propane mixture is continuously supplied to compensate for the loss in the gas as a result of hydrate formation and thereby to maintain a constant pressure inside the reactor. We performed continual gas chromatographic measurements of the gas phase inside the reactor during each hydrate forming operation to determine how the gas phase composition chronologically changes as a result of the fractionation accompanying the hydrate formation. These measurements showed an anomalous pattern of change in the gas phase composition, such that

title: Kinetics of structure II gas hydrate formation for propane and ethane using an in situ particle size analyzer and a Raman spectrometer
abstract: The kinetics of structure II gas hydrates, formed from pure propane and a mixture of propane and ethane, were investigated and intrinsic rate constants were regressed from the experimental data. The experiments were conducted in a semi batch stirred tank reactor equipped with an in situ particle size analyzer and connected to an external Raman spectrometer. Experiments were conducted with pure propane at temperatures ranging from 274 to 276 K and pressures ranging from 0.39 to 0.43 MPa. The intrinsic rate constant for ethane in structure II was subsequently regressed from experimental data on the formation of hydrates formed from an equimolar mixture of propane and ethane at 274 K and 0.35 MPa. Raman spectroscopy was used to verify that ethane was present only in the large sII cavity.

title: Clathrate Hydrate Formation from a Hydrocarbon Gas Mixture: Evolution of Gas Phase Composition in a Hydrate Forming Reactor
abstract: The clathrate hydrate formation from a model natural gas, i.e. a mixture of methane, ethane, and propane in a 90:7:3 molar ratio, under constant pressure was experimentally investigated, focusing on the evolution of the gas phase composition inside the hydrate forming reactor during each semi batch hydrate forming operation. In a previous study (Kobayashi, T. Imura, N. Ohmura, R. Mori, Y. H. Energy Fuels 2007, 21, 545 553) we measured the evolution of the gas phase composition during the initial period (up to ~3 h) following the inception of hydrate formation, in which the total amount of gas uptake in the formed hydrates was limited to 0.8 times the amount of gas initially contained in the reactor. This study extended the previous study, such that we could observe the evolution of the gas phase composition for a much longer time (up to ~50 h) until a quasi steady state was established inside a newly constructed gas bubbling type reactor equipped with a gas phase mixing stirrer that enabled the gas s.

title: Experimental Study On Formation of Propane Gas Hydrate By Fluidized Bed Type Reactor
abstract: This paper presents an experimental investigation for application of fluidized bed reactor to natural gas hydrate (NGH) production. Formation of gas hydrate requires the removal of formation heat. In this study, propane gas was used for the reason that propane gas hydrate (PGH) is formed under lower pressure condition than natural gas. Experiments on formation of PGH using fluidized bed reactor were conducted in batch operation and continuous operation. Residence time of powder required for the reduction of unconverted water content was obtained.

title: Two Step Formation of Methane Propane Mixed Gas Hydrates in A Batch Type Reactor
abstract: Vapor compositions of methane and propane mixed gas in a batch type reactor were measured by gas chromatography during hydrate crystallization at 274 K with molar ratios of propane below 10 vol The volume ratio of propane in the vapor decreased as the hydrate crystallization progressed. When the initial propane concentration was between 4 and 8 vol rapid gas consumption occurred for about 1 h, causing an initial pressure drop, and after a temporary stabilization of the pressure, a second pressure drop occurred; that is, hydrate crystallization occurred in two steps. X Ray diffraction and Raman spectroscopic analyses on samples taken from the reactor during each step revealed that the structure II methane propane mixed gas hydrates crystallized in the first step, and structure I methane hydrates in the second step. This process was observed only when the partial pressure of methane was above the equilibrium pressure of methane hydrate at the end of the first step.

title: Natural Gas Hydrate Formation and Decomposition in the Presence of Kinetic Inhibitors. 3. Structural and Compositional Changes
abstract: A synthetic natural gas mixture composed of methane, ethane, and propane in a batch reactor was used to form gas hydrates in the presence of two commercial, chemical kinetic inhibitors, polyvinylpyrrolidone (PVP) and H1W85281, and one biological inhibitor, antifreeze protein type III (AFP III) Powder X ray diffraction and nuclear magnetic resonance spectroscopy showed that structure II hydrates dominated, as expected, but in the presence of the chemical inhibitors, structure I was also present. Raman spectroscopy confirmed the complexity and the heterogeneity of the guest composition within these hydrates, which was also consistent with the gas analysis obtained using gas chromatography. However, in the presence of AFP III, hydrates appeared to be relatively homogeneous structure II hydrates, with weaker evidence of structure I. When individual gas cage occupancies were calculated, both classes of inhibitors reduced large cage methane occupancy by ~25% With the chemical inhibitors, these large cage meth.

title: Formation and Decomposition of Gas Hydrates from the Mixtures of Methane Ethane Methane Propane
abstract: Formation and decomposition of gas hydrates were carried out for two binary gas mixtures containing 90.01% CH4 9.99% C2H? and 90.05% C3H? 9.95% C3H? The formation of the gas hydrate was conducted in a semi batch stirred reactor at constant temperature and pressure. During the hydrate formations the gas compositions were measured by gas chromatograph. ft was found that the CH4 concentration in gas phase increased as the hydrate crystallization progressed and the accumulation speed of methane was more rapid at lower driving force. Based on the gas phase analysis with overall mass balance, we are able to estimate the gas consumption ratio in hydrate phase. Our results indicate that the molar ratio of CH4/C2H? or CH4/C3H? in the hydrate phase was decreased as hydrate formation progressed. The decomposition of the gas hydrate was also carried out either by decreasing pressure or increasing temperature. ft was also noticed that the dissociation rate of C2H? or C3H? from gas hydrates was slower than that of CH4 during the hydrate decomposition stage. This study could be useful for the natural gas storage and capturing kinetics of the guest molecules in hydrate phase form the gas mixtures.