Bhajan Lal

Measurement and prediction of physical properties of aqueous sodium salt of L-phenylalanine

Physical properties such as density, refractive index and viscosity of aqueous sodium salt of l-phenylalanine (Na-Phe) were investigated in this work. These properties were measured over a temperature range of 298.15-343.15 K, and at atmospheric pressure. The mass fractions ( w ) of Na-Phe were 0.05, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35 and 0.40 respectively. The analysis of the experimental data shows that the values of density, refractive index and viscosity decrease with an increase in temperature at any constant concentration of Na-Phe. However, these values increase with the rise of concentration isothermally. The density values were used for estimation of thermal expansion coefficient. The thermal expansion coefficient increases slightly with the increase in temperature and concentration. Density and refractive index data were correlated using modified Graber equation, while, viscosity data were correlated using modified Vogel-Tamman-Fulcher (VTF) equation. In all the cases, a quantitative analysis of the influence of temperature and concentration was carried out.

Study of 1-(2-hydroxyethyle) 3-methylimidazolium halide as thermodynamic inhibitors

In this study, the performance of 1-(2-Hydroxyethyle) 3-methylimidazolium chloride [OH-EMIM][Cl] and 1-(2-Hydroxyethyle) 3-methylimidazolium bromide [OH-EMIM][Br] was investigated as thermodynamic gas hydrate inhibitors. The dissociation temperature was determined for methane gas hydrates using a high pressure micro deferential scanning calorimeter at a pressure range of 36-97 bar. Both ionic liquids (ILs) were studied at concentrations of 5, 10, 15, 20 and 25 wt% then their performance was compared with commercially available inhibitors. It was observed that both ILs shift the methane hydrate equilibrium curve to lower temperature and higher pressure; and the performance of [OH-EMIM][Cl] is better than [OH-EMIM][Br]. Nevertheless both of them were found to be less effective compared to methanol and mono ethylene glycol.

Solubility of CO2 in an Aqueous Ammonium Based Ionic Liquid

The aim of this research is to find out the potential usage of water miscible ammonium based ionic liquids (ILs) towards CO2 capture. To measure the solubility of CO2 in 55 wt. % aqueous solution of Tetra butyl ammonium hydroxide (TBAOH), the experiments were carried out using high pressure solubility cell. Solubilities were determined in the temperature range of (303.15 to 333.15) K by varying the pressure from (2 to 10) bar and are reported as loading capacity (mol CO2/mol TBAOH). The solubility of CO2 in this aqueous IL decreased with increasing temperature and increased with increasing pressure.

Green silica scale inhibitors for Alkaline-Surfactant-Polymer flooding: a review

AbstractAlkaline-Surfactant-Polymer flooding is a tertiary enhanced oil recovery (EOR) method designed to lower interfacial tension (IFT), water wet the formation, and decrease water mobility to produce residual oil. The ASP flood uses a combination of alkali, surfactant, and polymer to achieve these results. The use of these three fluid injection additives offers great synergistic effects in terms of oil recovery and sweep efficiency. Despite its popularity as a potentially cost-effective chemical flooding method, it is not without (its) problems, one of which is the excessive formation of silicate scales. Silicate scale is a very serious problem in the oil and gas industry; which forms in perforation holes, casing surface, tubing, and surface facilities. This study reviewed and assessed some of the inhibition techniques used in the industry with regard to handling oilfield scales in general and silicates scales in particular. Besides, the inhibitors with enhanced functionality in mitigating silicate scale also have been discussed. However, the conventional scale inhibitors used are facing restrictions world over, due to their ecotoxicity and non-biodegradability, which, therefore, has led to the call for green scale inhibition in the oil and industry. Green scale inhibitors are considered as alternative scale inhibitors due to their value-added benefits to the environment with respect to the methods of treating oilfield scales.

Permeability Evaluation in Hydrate-Bearing Sand Using Tubular Cell Setup

Production of natural gas from hydrate-bearing sediments is significantly influenced by permeability variations in the presence of gas hydrate. The quantification on how absolute permeability and relative permeability affect natural gas production from hydrate-bearing sediments is one of the key interests for reservoir engineering studies. This study focuses on the relationship between water saturation, permeability, and porosity in unconsolidated quartz sand. Methane hydrate was formed in quartz sand in high-pressure stainless steel cell using deionized water at 276 K and 8 MPa. The sand pack with porosity of 40% was saturated with 35% water. This study found that porosity of the sample reduced significantly as the sand pack saturated with 35% of water. Porosity reduced from 40 to 37.4% due to the increase of hydrate saturation. Absolute permeability is 108.72 mD, and it was measured before gas hydrate formation. Relative permeability was measured after gas hydrate formation, and results show that relative permeability is 0.49. Formation of hydrate in pores significantly reduces the relative permeability and porosity. Relative permeability from this work is compared with a theoretical model, and the value shows that the relative permeability from this work is close to the value from Masuda model with N = 10.

Hydration Behavior Study of Imidazolium Based ILs in Water

These ILs were chosen to provide an understanding of the influence of the cation alkyl chain length, and the anion influence on the volumetric properties. Densities for aqueous solutions of ionic liquids having 1-butyl-3-methylimidazolium as cation and chloride, bromide, iodide and acetate as anions were accurately measured at various concentrations and temperature, (288.15, 293.15, 298.15, 303.15 and 308.15) K. The results have been discussed in terms of hydrophobic hydration, hydrophobic interactions, and water structural changes in aqueous medium. The data were used in evaluating thermodynamic properties as apparent molar volumes, and apparent molar expansions. Apparent molar volumes were found to increase with temperature.

Effect of Porosity to Methane Hydrate Formation in Quartz Sand

Natural gas hydrates are recognized as the potential source of methane gas as the current estimates of the global methane hydrates inventory range between 1000 and 10000 Giga Tonnes of carbon. The behavior of methane hydrate formation in porous media is investigated in the Tubular Hydrate Cell at 8 MPa and 276 K. The present work is focused on finding the optimum porosity of the quartz sand with the grain sizes of 600–800 µm that could accelerate the methane hydrate formation. The effect of different porosity (O of 0.32, 0.34, 0.37, and 0.4) on the methane hydrate induction time, methane hydrate saturation, and the time taken for methane hydrates to completely form in the unconsolidated sand is investigated. The result shows that the optimum value for porosity is 32% based on the fastest time taken for complete formation and largest value of methane hydrate saturation which is 33.35 h and 6.34%, respectively, at the specified operating conditions.