M.A. Bustam

Removal of high concentration CO2 from natural gas at elevated pressure via absorption process in packed column

Abstract Carbon dioxide (CO2) removal is an essential step in natural gas (NG) processing to provide high quality gas stream products and minimize operational difficulties. This preliminary study aims to investigate the removal of CO2 at high concentration level from the mixture of CO2-NG gas stream at elevated pressure via absorption process. This is to explore the possibility of exploring high CO2 content natural gas reserves by treatment at offshore platform. A mixed amine solvent, Stonvent-II, was used for the absorption of approximately 75 vol% CO2 in CO2-NG stream at a pressure of 10 barg. The initial solvent temperature was varied in order to study the impact of initial temperature on the absorption performance. Preliminary study at temperatures of 35°C and 45°C indicates that Stonvent-II was able to perform almost 100% removal of CO2 under both conditions. However, the CO2 absorption effect took place faster when the initial liquid temperature was lower. This is because when the initial liquid temperature is high, the temperature increase in the packing bed caused by the reaction heat is high which impacts the efficiency of absorption negatively.

Synthesis and anti-microbial activity of hydroxylammonium ionic liquids

Eight hydroxylammonium-based room temperature ionic liquids (ILs) have been synthesized by acid-base neutralization of ethanolamines with organic acids. The ILs were characterized by infrared and nuclear magnetic resonance spectroscopies and elemental analysis. Their anti-microbial activities were determined using the well-diffusion method. All eight ILs were toxic to Staphylococcus aureus, while 2-hydroxyethylammonium lactate and 2-hydroxy-N-(2-hydroxyethyl)-N-methylethanaminium acetate showed high anti-microbial activity against a wide range of human pathogens.

Physical properties of aqueous solutions of potassium carbonate+glycine as a solvent for carbon dioxide removal

The physical properties such as densities, viscosities, and refractive indices of aqueous solutions of potassium carbonate (PC) blended with glycine (Gly) as solvent blends for CO2 capture were measured. The properties were measured at ten different temperatures from (298.15 to 343.15) K. The mass fractions (w1 + w2) % of the (PC + Gly) blends were (0.05 + 0.01, 0.10 + 0.02, 0.15 + 0.03, 0.20 + 0.04, 0.25 + 0.05, 0.30 + 0.06, 0.35 + 0.07, and 0.40 + 0.08), respectively. The analysis of experimental results shows that, the densities, viscosities, and refractive indices of the aqueous (PC + Gly) blend increase with increasing the concentration of the potassium carbonate and glycine, and decrease with decreasing the temperature. The experimental data of density, viscosity and refractive index were correlated by a least-squares method as a function of temperature. The predicted data were estimated from coefficients of correlation equations for all measured properties, and reported with standard deviation (SD). The experimental data are in consistent with the predicted data.

Computational insights on the role of film thickness on the physical properties of ultrathin polysulfone membranes

Although it has been reported that physical properties of polymeric membranes inherit thickness dependent characteristics, typically when they are subjected to confinement at an ultrathin dimension (<1000 A), deviations from their bulk counterpart are still not completely understood. An empirical investigation of physical properties for an ultrathin membrane at laboratory scale is difficult, time consuming, and costly which is attributed to challenges to fabricate defect-free films with ultrathin thickness and that requires special instruments at critical conditions. In our current work, a Soft Confining Methodology for Ultrathin Films was conducted to simulate ultrathin polysulfone polymeric membranes of varying thicknesses, l, to resemble their actual size in the thickness dimension. Subsequently, physical properties of the constructed ultrathin films, e.g., density and glass transition temperature, have been elucidated from an atomistic insight. Quantitative empirical models have been proposed to capture thickness-dependent physical properties upon ultrathin confinement. In addition, free volume and cavity distribution was also quantified in order to elucidate the evolution in membrane morphology and to satisfy a previous research gap of deficiency in system dimension dependent cavity sizes. On the whole, it was found that a thinner structure exhibits higher structural density and lower glass transition temperature, as well as lower free volume and cavity sizes. The findings from the present work are anticipated to propose an alternative from a molecular simulation aspect to circumvent complexities associated with experimental preparation and testing of ultrathin polymeric membranes, while providing direct elucidation and quantification of thickness-dependent physical properties in order to enhance understanding at a molecular perspective.