The effect of viscosity of dispersed phase on coalescent filtration

Abstract

Oily water is formed in: oil production and refining, petrochemical, pharmaceutical, chemical and food production, metal processing as well as in services for vehicles and ship maintenance. Due to the wide application of coalescence filtration for the treatment of different kind of oily water and complexity of the phenomenon, the design of appropriate coalescer with specific characteristics precede extensive semiindustrial research. In process industry, it is necessary to separate the dispersed oil phase of different nature, and the viscosity is one of the important characteristics affecting the separation. The aim of this study is to investigate the viscosity influence of the dispersed oil phase on the coalescence filtration efficiency using two waste polymer fiber beds over different bed permeabilities. Three different model emulsions obtained by dispersing the oil phase: domestic oil - A, fractions of domestic oil - A4, mixed intermediate product - P1 in drinking water were investigated. Experiments were carried out for bed permeability range from 0.18∙10-9 to 5.389∙10-9 m2. Waste polyethylene terephthalate - BA1 and waste polypropylene - PP were used. The velocity was kept in the range from 19 to 70 m/h. In the case where the viscosity of the dispersed phase ranges from 10 to 168 mPa s, the bed filter in the coalescer should be BA1 material with low bed permeability. While in the case of higher viscosity, above 80mPa s, the bed filter in the coalescer should be PP material with high bed permeability because in these circumstances greater operating velocity of 55 m/h is achieved resulting in the reduction of the coalescer dimensions.