Development of carbon based composites for filtering elements used on bilge's oily water treatment units

Abstract

Due to complicated ingredients contained within bilge's oily water on board ships, efficient separations as per the relevant standard cannot be easily handled while considering the cost and performance of the filter elements currently used. In this research, activated carbon and expanded natural graphite (ENG) were employed to synthesize the composite adsorbent for adsorption of the emulsified oil. Orthogonal experiments were designed to determine the processing parameters for synthesizing activated carbon from potassium hydrate and phenolic resin, composite adsorbents were prepared by mixing ENG with different mass ratios and densified to a density comparable to that of the commercially available filtering material. Comparisons between the composite and filtering materials were made in terms of structure, morphology, adsorption equilibrium as well as the strength and stability under typical loads and impacts. It showed that the activated carbon sample prepared by the impregnation ratio, heating temperature and heating duration respectively about 4:1, 650 °C and 2 h had a better adsorptive performance. It also revealed that, within 298.15 K–308.15 K, in comparing with those on the commercially available filtering material, the AE-10 sample prepared by mixing 10 wt% ENG and densified to 0.03 g cm−3 had 270% increment in adsorption amount of the emulsified oil and one seventh deformation in size as well as one tenth mass loss in weight, respectively. It suggests that the composite formed by ENG and the activated carbon sample having larger specific mesopore volume and surface area are promising for the treatment of onboard oily water.