IMPROVED LABORATORY DEMULSIFICATION TESTS FOR OIL SPILL RESPONSE

Abstract

ABSTRACT A critical need currently exists for standard laboratory procedures for evaluating demulsifiers over the range of applications encountered in oil spill response. The procedures should be flexible enough to generate emulsions that are representative of those encountered at various times during a spill situation, and the applications should cover emulsion inhibition, breaking emulsion slicks at sea, and breaking recovered emulsions. Two laboratory test procedures are proposed. The procedures have different mixing energy and treating conditions, but each has the desirable feature of utilizing the same apparatus to generate the emulsion and to test the demulsifier. One procedure, called the wrist-action shaker emulsion test (WRASET), utilizes a standard laboratory apparatus, and is applicable for emulsion inhibition and for simulating at-sea applications of demulsifiers. A second procedure, called the rotating flask emulsion test (ROFLET), can also be used for a range of applications and is applicable for treating emulsions during oil recovery operations. Data from each of the two laboratory emulsion tests are used to demonstrate their features and to provide guidance on their use. An important implication of this work is that laboratory tests currently used to evaluate the effectiveness of dispersants to break up emulsions at sea need to be modified to provide time for the emulsions to be first broken by the dispersant.