Muhammad Sagir - Surfactants for Enhanced Oil Recovery Applications

Chemical Engineering, University of Gujrat, Gujrat, Pakistan

PETRONAS Research Sdn. Bhd., Selangor, Malaysia

Chemical Engineering, University of Gujrat, Gujrat, Pakistan

Department of Physics, University of Gujrat, Gujrat, Pakistan

ADNOC, Abu Dhabi, United Arab Emirates

Dr. Muhammad Mushtaq

Springer Nature Switzerland AG 2020

Muhammad Sagir

Surfactants are organic compounds, also termed as surface active agents. Surfactants contain at least one lyophilic (solvent-loving) and at least one lyophobic (solvent-fearing) group in the molecule. In usual circumstances, the solvent is water and the terms hydrophobic and hydrophilic are used for solvent-fearing and solvent-loving groups, respectively. Traditionally, the polar group is termed as head, and the long non-polar chain is known as tail (see Fig. ). The hydrophilic group is usually polar and is soluble in water while the hydrophobic group is non-polar and is water-insoluble, soluble in non-polar phases. Due to this unique ability to have two different groups available in the same molecule, surfactants act on the interface of two immiscible phases (e.g., water and oil) and lower the interfacial tension (IFT) between these two phases. During this IFT lowering process, the hydrophilic part of the surfactants remains in the water, while the hydrophobic part tries to remain in the oil, making more contact between the two phases and causes the IFT to reduce. The interfacial tension is called surface tension when air is in the non-polar phase.

The ability of surfactants to act on the interface makes them unique in the chemical industry, and therefore, the surfactants play a major role in many industrial and household applications. They are used in domestic and industrial processes for cleaning, wetting, dispersion, emulsification, foaming, and antifoaming applications. Numerous industrial and household chemical formulations use surfactants as detergents, soaps, shampoos, inks, paints, adhesives, herbicides, firefighting chemicals, leak detectors, and as active agents for enhanced oil recovery (EOR) applications. Due to these multifarious applications, surfactants capture a remarkable portion of the chemical market. Anionic surfactants are the major players in the surfactant market, and their global demand in 2010 was 6.5 million tons.

Depending on the charge present on their head group in solutions, surfactants are divided into four types: anionic, cationic, non-ionic, and amphoteric surfactants.