نمایش همه 2 نتیجه
Experimental investigation of gas consumption for simple gas hydrate formation in a recirculation flow mini-loop apparatus in the presence of modified starch as a kinetic inhibitor
The main objective oرایگان!
The main objective of the present work is to investigate experimentally of simple gas hydrate formation with or without the presence of kinetic inhibitors such as modified starch in a recirculation flow mini-loop apparatus. For this purpose, a laboratory recirculation flow miniloop apparatus was set up to measure the induction time for hydrate formation and gas consumption rate when a hydrate forming substance (such as C1, C3, CO2 and i-C4) is contacted with water in the absence or presence of dissolved inhibitor under suitable temperature and pressure conditions. In each experiment, a water blend saturated with pure gas is circulated up to a required pressure. Pressure is maintained at a constant value during experimental runs by means of the required gas make-up. The effect of pressure on gas consumption during hydrate formation is investigated with or without the presence of poly vinylpyrrolidone (PVP) and modified starch as kinetic inhibitors at various concentrations. Our results were shown that the modified starch can be applied as inhibitors in prevention of simple gas hydrate formation in mini-loop apparatus
Investigation of Six Imidazolium-Based Ionic Liquids as Thermo-Kinetic Inhibitors for Methane Hydrate by Molecular Dynamics Simulation
The thermo-kinetic iرایگان!
The thermo-kinetic inhibition mechanism of six imidazolium-based ionic liquids (ILs) on methane clathrate hydrate formation and growth is studied in this work using classical molecular dynamics (MD) simulation. The ionic liquids investigated include 1-(2,3-dihydroxypropyl)-3-methylimidazoliumbis(fluorosulfonyl)imide ([C3(OH)2mim][f2N]), 1-(2-hydroxyethyl)-3-methylimidazolium bis(fluorosulfonyl)imide ([C2OHmim][f2N]), 1- ethyl-3-methylimidazolium tetrafluoroborate ([C2mim][BF4]), 1-butyl-3-methylimidazolium tetrafluoroborate ([C4mim][BF4]), 1-butyl-3-methylimidazolium acetate ([C4mim][OAc]) and 1-ethyl-3-methylimidazolium ethylsulfate ([C2mim][EtSO4]). Simulations showed that [C2OHmim][f2N] and [C3(OH)2mim][f2N] are strongly hydrated compared to other ILs because of hydrogen bonding between OH groups of the cation and water molecules. They also exhibit high diffusion rates towards crystal surface and bond to it through strong intermolecular interactions. As a result, these two ILs are stronger thermo-kinetic inhibitors for formation and growth of methane hydrates compared to other ILs studied in this work as well as conventional inhibitors like methanol and NaCl. The simulations also revealed that cations of [C3(OH)2mim][f2N] and [C2OHmim][f2N] show that the presence of ions near the hydrate crystal causes hindrance for water and guest molecules adsorbing on the hydrate surface, which inhibits the growth of hydrate crystals. In addition, it is shown that [C3(OH)2mim][f2N] and [C2OHmim][f2N] are more likely to inhibit hydrate formation