Development of bio-inspired Coalescing Filter for water-fuel separation

Context of research:
Effective fuel-water separation technology is of paramount importance for many application especially in the automotive industry where the presence of water contaminant in the fuel can reduce engine performance and cause severe damage to the injectors by promoting corrosion and microbial growth. In recent years, the societal drive toward greener fuel technology as resulted in tighter emission regulation and new diesel fuels blend. This change in formulation however has an adverse effect on the performance of traditional fuel filters and their ability to separate emulsified water. Indeed, these additives reduce interfacial tension between the water and the diesel leading to formation of more stable emulsions and the generation of smaller water droplets that are harder to remove. This experimental research project will address the challenge by developing and studying the performance of a new type of fuel-water filter combining a depth coalescing non-woven medium and a barrier mesh. The project will focus on the fabrication, characterization and performance of such mixed filter. Using a biomimetic approach to the problem, materials will be designed with a range of porosity and wettability (from superhydrophobic to superoleophobic) and the performance of the ad-hoc filters will be systematically assessed against the characteristics of water-in-fuel emulsion.

Aims and objectives.
The main aims are i) to use a biomimetic approach to advance the fabrication of mixed filters combining coalescing medium barrier mesh and ii) carry out an accurate study of the performance of mixed filter against the characteristics of water-in-fuel emulsion to provide an insight into the relationship between the structure of the filter, its operating environment and performances.

The objectives are:
To develop bio-inspired strategies that enable control at the nanoscale using PECVD technologies to alter surface wettability. Through interfacial physicochemical modification; filters exhibiting a range of wettability (from super-hydrophilic to super-oleophilic) will be used to conduct a detailed study of the heterogeneous nucleation, growth and coalescence properties of such interfaces. The project will systematically investigate the relationship between the properties of the filters (e.g., wettability, porosity), their efficiencies ( e.g., pressure drop, life expectancy, residual water) and the properties of the water-diesel emulsions (e.g. water content, droplet size, viscosity, interfacial tension) to offer a new insight onto the factors affecting water removal from fuels.

Potential applications and benefits
The multidisciplinary project will provide a stepping stone toward the development of advanced liquid-liquid separation technologies that will benefits many industries (e.g. oil spill, automotive industry, liquid extraction). The science at the core of this project will help to understand the complex physic of interfacial coalescence mechanisms and multiphase flow in porous media.