Search for: All records

Abstract Nonionic surfactants are increasingly being applied in oil recovery processes due to their stability and low adsorption onto mineral surfaces. However, these surfactants lead to the production of emulsified oil that is extremely stable and difficult to separate by conventional methods. This research characterizes the stability of crude oil mixed with a nonionic surfactant, L24–22, in a brine solution. When subjected to gravity separation, a middle oil‐rich and bottom water‐rich emulsion are generated for various water–oil ratios. Thermal treatments can effectively break oil‐rich emulsions, but the bottom water layer remains contaminated with micron‐sized crude oil droplets. A magnetic nanoparticle treatment is shown to demulsify the crude oil emulsions, dropping the total organic carbon (TOC) in the water layer from 1470 to 30 ppm. 

Asphaltenes are the heaviest and most polarizable fractions of crude oil. During the oil production process, changes in the temperature, pressure, and oil composition can destabilize asphaltenes. This destabilization leads to asphaltene aggregation and deposition, which can cause major clogging problems in both the wellbore and near-wellbore regions as well as the production facilities. In this study, we developed and investigated the application of acrylic acid and 2-acrylanmido-2-methylpropanesulfonic acid (AA–AMPS)-functionalized magnetic nanoparticles as a surface coating in inhibiting asphaltene deposition. The use of the porous media microfluidic platform allows for efficient evaluation of the effectiveness of the nanoparticle coating in mitigating asphaltene deposition in various crude oils. We demonstrated that the nanoparticle coating is effective in inhibiting asphaltene deposition, showing up to a 75% improvement in permeability change. The study also explores the dynamics of asphaltene aggregation and deposition in different crude oils. We identified factors such as asphaltene aggregate size as well as the physical and chemical characteristics of the aggregates that can determine the effectiveness of different mitigation methods. 

Active colloids use energy input at the particle level to propel persistent motion and direct dynamic assemblies. We consider three types of colloids animated by chemical reactions, time-varying magnetic fields, and electric currents. For each type, we review the basic propulsion mechanisms at the particle level and discuss their consequences for collective behaviors in particle ensembles. These microscopic systems provide useful experimental models of nonequilibrium many-body physics in which dissipative currents break time-reversal symmetry. Freed from the constraints of thermodynamic equilibrium, active colloids assemble to form materials that move, reconfigure, heal, and adapt. Colloidal machines based on engineered particles and their assemblies provide a basis for mobile robots with increasing levels of autonomy. This review provides a conceptual framework for understanding and applying active colloids to create material systems that mimic the functions of living matter. We highlight opportunities for chemical engineers to contribute to this growing field.