A Novel Separation Technology for Biofuel Harvesting from Wastewater

该研究计划将开发一种膜分离技术，用于从经济和环境可持续的废水中有效地收集生物燃料。虽然将废水中的有机材料转化为生物燃料的技术（例如，生物甲烷、生物乙醇和生物柴油），但这些生物燃料是不可用的形式，例如溶解的气体或液体混合物，因此需要额外的提取步骤。一种潜在的解决方案膜分离工艺是节能的，并且需要很小的环境足迹。然而，目前还没有有效的膜技术用于分离所产生的生物燃料，这是由于低选择性和结垢使得膜过程无效且昂贵。该提案解决了当前膜技术实现从废水中高效收集生物燃料的两个关键挑战：（1）低选择性和（2）严重污染。为了实现高选择性，将开发一种极其抗润湿的全憎膜。该膜将置于进料溶液（生物燃料和废水混合物）和汲取溶剂（对生物燃料具有高溶解度但对水具有低溶解度的有机溶剂）之间。溶解度差异驱使生物燃料作为气体进入汲取溶剂，而水由于汲取溶剂中的溶解度差而被排斥，导致生物燃料的高选择性。此外，还将开发一种使用刺激响应材料的自清洁表面涂层，用于长期可持续的膜。响应于诸如电压变化的外部刺激，膜的表面涂层破裂，从而去除膜表面上沉积的污垢。作为一个潜在的应用，我们将展示从厌氧处理的废水的流出物中长期可持续地收获生物甲烷。** 开发的技术将大大增加可再生能源供应，减少温室气体（GHG）排放。从经济上讲，废水中的甲烷可以补充加拿大住宅区约21%的能源使用。在环境方面，充分利用废水中的生物甲烷相当于消除加拿大50多万辆汽车排放的温室气体。从长远来看，拟议的研究计划将为水-食品-能源关系的进一步创新铺平新的道路，为加拿大提供重大的经济和环境效益。

This research program will develop a membrane separation technology for efficiently harvesting biofuel from wastewater that is economically and environmentally sustainable. Although technology that converts organic materials in wastewater into biofuels (e.g., biomethane, bioethanol and biodiesel) currently exists, these biofuels are in non-usable forms such as dissolved gas or liquid mixtures, and therefore necessitates an additional extraction step. One potential solution membrane separation process is energy-efficient and requires a small environmental footprint. However, currently there exists no effective membrane technology for separation of the produced biofuels due to low selectivity and fouling that make the membrane processes ineffective and expensive.******This proposal addresses two key challenges of current membrane technology to achieve highly efficient biofuel harvesting from wastewater: (1) low selectivity and (2) severe fouling. To achieve high selectivity, an extremely wetting resistant omniphobic membrane will be developed. This membrane will be placed between a feed solution (biofuel and wastewater mixture) and a draw solvent (organic solvent that has high solubility for biofuel but low solubility for water). The solubility difference drives biofuel as a gas into the draw solvent, while water is rejected due to the poor solubility in the draw, leading to a high selectivity of biofuels. In addition, a self-cleaning surface coating will be developed using stimuli-responsive materials for membranes sustainable in the long run. In response to external stimuli such as voltage change, the surface coating of the membrane disrupts, removing the deposited foulants on the membrane surface. As a potential application, we will demonstrate the long-term sustainable harvesting of biomethane from an effluent of anaerobically treated wastewater. ******The developed technology will significantly boost renewable energy supply and reduce greenhouse gas (GHG) emissions. Economically, methane from wastewater can supplement up to approximately 21% of energy use in residential areas in Canada. Environmentally, the full utilization of biomethane from wastewater is equivalent to removing GHG emitted from more than half a million cars in Canada. In the long run, the proposed research program would pave a new path for further innovations in the water-food-energy nexus, providing significant economic and environmental benefits to Canada.