ABSTRACT
In actual operation, FFAs in the oil are neutralized by aqueous NaOH. The soap that is formed is solubilized with isopropyl alcohol (IPA). This results in a two-phase system: the aqueous phase consists of water, IPA, and soap, and the oil phase contains primarily triglycerides, with traces of IPA and soaps. The emulsion is first passed over a hydrophilic membrane operating at pres sures below the ingress pressure of the nonwetting phase. Water, IPA, and soap pass through the membrane while almost all the oil is retained. The retentate still contains significant amounts of the aqueous phase components. It is now directed over a hydrophobic membrane, operating below the Laplacian pressure of water. This membrane rejects almost all the aqueous substances while allowing the free passage of oil. This oil is substantially deacidifled. The retentate from this stage is recycled to the reactor and the process is continued.
