study on the effect of demulsifers on crude oil and petroleum products

the oil refining industries are using a number of demulsifiers for dewatering and desalination of crude oil but experience has shown that universal demulsifiers can not be produced. each kind of water in oil (w/o) emulsion requires specific by composition demulsifier. in practice, synergetic effect of the interaction between different types of demulsifiers is often sought. for dewatering the water in oil emulsion of crude oil from the ural region, 16 kinds of demulsifiers were tested, named d1 ÷ d16. with combinations of demulsifiers, the highest rate of emulsion drying was observed with mixture 1 (2.5 ppm of demulsifier d5 and 2.5 ppm of demulsifier d9). for the emulsion of water with diesel fraction boiling in the temperature range 180-360°c, mixture 1 at concentration of 20 ppm gave the optimal effect in breaking the emulsion. the results obtained from the experiments showed that the overdosing of demulsifier did not lead to optimal emulsion breaking and laboratory and industrial scale experiments should be carried out to break specific emulsion.