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

研究背景：有效的燃料-水分离技术对许多应用至关重要，特别是在汽车行业，燃料中存在的水污染物会降低发动机性能，并通过促进腐蚀和微生物生长而对喷油器造成严重损害。近年来，社会对更绿色燃料技术的推动导致了更严格的排放法规和新的柴油混合燃料。然而，配方的这种变化对传统燃油滤清器的性能和分离乳化水的能力产生了不利影响。事实上，这些添加剂降低了水和柴油之间的界面张力，导致形成更稳定的乳状液，并产生更小的水滴，更难去除。本实验研究项目将通过开发和研究一种新型燃料-水过滤器的性能来应对这一挑战，该过滤器结合了深度聚结非织造布介质和屏障网。该项目将专注于这种混合过滤器的制造、表征和性能。使用仿生学的方法来解决这个问题，材料将被设计成具有一定范围的孔隙率和润湿性(从超疏水到超疏油)，并将对照燃料中水乳状液的特性对特别过滤器的性能进行系统的评估。其主要目的是：i)利用仿生方法推进结合聚结介质屏障网的混合过滤器的制造；ii)针对燃料中水乳状液的特性，对混合过滤器的性能进行准确的研究，以深入了解过滤器的结构、运行环境和性能之间的关系。目标是：开发生物灵感策略，使用PECVD技术改变表面润湿性，实现纳米级的控制。通过界面物理化学改性，将使用表现出一定范围的润湿性(从超级亲水到超级亲油)的过滤器来详细研究此类界面的异质成核、生长和结合特性。该项目将系统地研究过滤器的性能(例如，润湿性、孔隙率)、它们的效率(例如，压降、预期寿命、残余水分)和水-柴油乳状液的性能(例如，水含量、液滴大小、粘度、界面张力)之间的关系，以提供对影响燃料除水的因素的新见解。潜在的应用和益处该多学科项目将为先进的液-液分离技术的开发提供踏脚石，这些技术将使许多行业受益(例如，石油泄漏、汽车工业、液体开采)。该项目的核心科学将有助于理解多孔介质中界面聚结机制和多相流的复杂物理学。

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.