Abstract
As the amount of oilfield produced water (PW) keeps going up, highly efficient flotation agent is needed. In this paper, a series of surfactants (abbreviated as Q-PTEA-Cn) derived from polytriethanolamine were synthesized. Their surface activities and flotation performance were evaluated. The result showed that the Q-PTEA-Cns can effectively reduce the surface tension of water and interface tension of crude oil/water. The Q-PTEA-C12-1 had the best flotation performance and the rational flotation condition was recommended as follows: Q-PTEA-C12-1 dosage 100 mg/L, gas flow 3 L/min, and flotation time 20 minutes. At this condition, the oil removal efficiency of two commonly used flotation agents (FL-1 and FL-2) and Q-PTEA-C12-1 were 62.3%, 69.1%, and 83.6%, respectively. The flotation kinetic of Q-PTEA-C12-1 can be described by Maruyama’s flotation model, which presented that there was adsorption of oil droplet adsorbed surfactant onto bubble. Floatation mechanism study confirmed that the Q-PTEA-C12-1 can absorb onto the oil droplet and showed that the Q-PTEA-C12-1 can enhance the bubble–drop attachment efficiency and the stability of bubble–drop agglomerates.