Extraction and oxidative desulfurization of bitumen from oil sand using n-pentane and ultrasound

Oil sand contains about 15 wt% bitumen which contains approximately 5 wt% sulfur. Bitumen must be extracted from sand and desulfurized before use as a fuel. Currently, bitumen is recovered from sand using hot water (80 °C) and sulfur is removed by hydrodesulfurization (200–450 °C), which both consume large amounts of energy. Therefore, we investigated the separation of bitumen from sand and the oxidative desulfurization of bitumen using ultrasound and n-pentane at 20 °C. We successfully extracted 95 wt% bitumen from sand and removed 66.1% of the sulfur by oxidative desulfurization using 15 wt% H2O2 and 5 mol/L NaOH.

Applications of Geophysical Methods in Tunnel and Oil Exploration

Geophysical studies can be utilized adequately to decide the land, hydro geographical and geotechnical properties of the ground mass in which the designing development is occurring. The investigation must be given to the contractor to ensure the information related to soil or to predict the type of equipment to be used and to estimate productivity and cost. This article examined how integrated geophysical methods were carried out for the determination of the degree of fracturing and rigidity of rock mass. Data were collected from different case studies in which comparison is there between different types of methods suited for different type of evaluations. In this paper, methods involved for the explorations are seismic refraction method, electrical resistivity method, magnetic and gravity method for oil explorations. The authors found that gravity and magnetic are best suited methods for the oil sand exploration and because of the high acceptance of designing a lot latest applications expected in future. The techniques used in these methods are relatively cheap and fast finding in comparison to other methods.

Spotlight onto surfactant–steam–bitumen interfacial behavior via molecular dynamics simulation

Heavy oil and bitumen play a vital role in the global energy supply, and to unlock such resources, thermal methods, e.g., steam injection, are applied. To improve the performance of these methods, different additives, such as air, solvents, and chemicals, can be used. As a subset of chemicals, surfactants are one of the potential additives for steam-based bitumen recovery methods. Molecular interactions between surfactant/steam/bitumen have not been addressed in the literature. This paper investigates molecular interactions between anionic surfactants, steam, and bitumen in high-temperature and high-pressure conditions. For this purpose, a real Athabasca oil sand composition is employed to assess the phase behavior of surfactant/steam/bitumen under in-situ steam-based bitumen recovery. Two different asphaltene architectures, archipelago and Island, are used to examine the effect of asphaltene type on bitumen's interfacial behavior. The influence of having sulfur heteroatoms in a resin structure and a benzene ring's effect in an anionic surfactant structure on surfactant–steam–bitumen interactions are investigated systematically. The outputs are supported by different analyses, including radial distribution functions (RDFs), mean squared displacement (MSD), radius of gyration, self-diffusion coefficient, solvent accessible surface area (SASA), interfacial thickness, and interaction energies. According to MD outputs, adding surfactant molecules to the steam phase improved the interaction energy between steam and bitumen. Moreover, surfactants can significantly improve steam emulsification capability by decreasing the interfacial tension (IFT) between bitumen and the steam phase. Asphaltene architecture has a considerable effect on the interfacial behavior in such systems. This study provides a better and more in-depth understanding of surfactant–steam–bitumen systems and spotlights the interactions between bitumen fractions and surfactant molecules under thermal recovery conditions.