Destabilisation of oil droplets in produced water from alkaline- surfactant-polymer flooding by using asymmetric pvdf membrane

• Auteur principal: Azierah Ramlee
• Format: Thèse
• Langue: anglais; anglais
• Publié: 2018
• Sujets: TN799.5-948 Nonmetallic minerals
• Accès en ligne: https://eprints.ums.edu.my/id/eprint/45200/1/24%20PAGES.pdf; https://eprints.ums.edu.my/id/eprint/45200/2/FULLTEXT.pdf

This thesis presents a study of destabilisation of oil droplets that produced from alkaline-surfactant-polymer (ASP) flooding by using four types of laboratory­fabricated polyvinylidene fluoride (PVDF) membranes. Four formulations of PVDF membranes were fabricated via immersion precipitation method with ethanol (0 - 30 %, v/v) as the coagulant to control the membrane formation. The membrane morphology and structures as well as pore sizes were characterised by using scanning electron microscopy (SEM), while the thickness was measured by a digital micrometre, and the porosity was determined by gravimetric method. The radius of oil droplets in feed and permeate solutions was measured by dynamic light scattering device. The membranes with the effective area of 17.35 cm2 were tested with synthesized ASP solutions that contained 1500 mg/L of the oil droplets. The oil droplets for feed solution ranged from 10-200 nm to 700-4000 nm with the mean radius 61 nm. Results show that with increasing of ethanol concentration, a pore size at the top and bottom surface become larger. Macrovoid structure formed near to the top surface and the sponge-like structure exhibited at the bottom. As ethanol concentration increased, the membrane porosity increased slightly from 77-83%, while thickness has no significant effects. The distilled water permeation flux increased from 27 .37 to 74.69 kg/m2min at 2 bar transmembrane pressure when the ethanol coagulant increased. Hagen-Poiseuille law and Darcy's law models were suggested to govern the permeation fluxes. The mean values of the membrane thickness, porosity and pore size were used to predict the fluxes. The membrane resistance was approximately 1011 m-1. The SEM was defective in the mean pore size measurement. When synthesized ASP produced water used as feed solutions, the flux and fouling resistance increased with the transmembrane pressures from 0 to 4 bars. The oil droplets radius in permeates increased to 20 - 4000 nm with mean radius 200 to 3000 nm. It proved that the destabilisation of the oil droplets took place when the ASP solution permeated through the asymmetric PVDF membranes especially for 2 and 4 bar transmembrane pressure. while no significant influence by the different formulation of asymmetric membrane structures. The membrane fouling increased as the flux decreased over time fitted the Darcy's law.