Separation of Water in Diesel Using Filter Media Containing Kapok Fibers

Abstract

Traditional water-repellent filter media for water separation in diesel fail to meet requirements due to the high content of surfactants in low sulfur diesel and ULSD (ultra low sulfur diesel). To improve the water separation performance of filter media, a novel dual-layer filter medium was prepared by hydrophilic fibers (glass microfibers) and hydrophobic fibers (kapok fibers and bi-component PET fibers). The results showed that the separation efficiency of a filter medium (sample #2) with the upstream layer containing 20 wt% kapok fibers was 89.5%, which was higher than that of filter samples with the upstream layer containing 0 wt%, 40 wt%, 60 wt% and 80 wt% kapok fibers. When the interfacial tension (IFT) of water in diesel was 21 mN/m, 17 mN/m and 13 mN/m, the separation efficiency of filter sample #2 was 99.5%, 89.5% and 30.5%, respectively, which was 23.9%, 57.4% and 17.8% higher than that of the commercial water-repellent filter samples composed of a polybutylene terephthalate (PBT) fiber layer and cellulose fiber layer.

The Effect of Surface Interactions on the Coalescence of Water Droplets in Fuel

“…Entrained water droplets deteriorate the performance of the engine by reducing its combustion efficiency, thus increasing the amount of hydrocarbon emissions. 1 The entrained droplets could also damage the diesel engines by corroding crucial engine components. In order to avoid these adverse effects on the fuel engine, it is critical to separate entrained water from the fuel.…”

“…The study postulated that the fluorochemical coating caused mono-olein to adsorb to the surface, thus decreasing the concentration of mono-olein on the water−fuel interface and leading to enhanced coalescence. A similar observation was reported by Song et al 1 in which the contact angle of water droplet in diesel fuel on glass fibers was measured. It was determined that the increase in concentration of surfactants led to a decrease in IFT and an increase in contact angle.…”

“…One of the major impurities in fuel is water. Entrained water droplets deteriorate the performance of the engine by reducing its combustion efficiency, thus increasing the amount of hydrocarbon emissions . The entrained droplets could also damage the diesel engines by corroding crucial engine components.…”

The Analysis of Fluid Flow on Different Kapok Filter Orientations using Computer Fluid Dynamics

“…However, the effectiveness of the design and orientation of the filter in the water is still questionable. There is still a lack of knowledge and study on the design and orientation of the filter [19,20]. C.-G. Liang et al [21] did mention that the flow distribution does affect the filtering efficiency since it might influence the trajectories of particle motions and collisions.…”