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于许多应用至关重要，特别是在汽车工业中，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对喷油器造成严重损害。近年来，社会对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，这种配方的变化对传统燃油滤清器的性能及其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，从而形成更稳定的乳液，并产生更小的水滴，更难去除。这个实验研究项目将通过开发和研究一种结合深度聚结无纺布介质和屏障网的新型燃油水过滤器的性能来解决这一挑战。该项目将重点研究这种混合滤波器的制造、表征和性能。采用仿生方法解决问题，将设计具有一系列孔隙度和润湿性（从超疏水到超疏油）的材料，并根据燃料中水乳液的特性系统地评估特设过滤器的性能。目的和目标。主要目的是i)使用仿生方法推进结合聚结介质阻挡网的混合过滤器的制造；ii)对混合过滤器的性能与燃料中水乳液的特性进行精确的研究，以深入了解过滤器的结构，其操作环境和性能之间的关系。目标是：开发生物启发策略，利用PECVD技术在纳米尺度上控制表面润湿性。通过界面物理化学改性；具有一系列润湿性（从超亲水性到超亲油性）的过滤器将用于对这些界面的非均相成核、生长和聚结特性进行详细研究。该项目将系统地研究过滤器的特性（如润湿性、孔隙度）、效率（如压降、预期寿命、残余水）和水-柴油乳剂的特性（如含水量、液滴大小、粘度、界面张力）之间的关系，为影响燃料脱水的因素提供新的见解。该多学科项目将为先进的液液分离技术的发展提供一个跳板，这将有利于许多行业（如石油泄漏、汽车工业、液体提取）。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。

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.