A Novel Separation Technology for Biofuel Harvesting from Wastewater

该研究项目将开发一种膜分离技术，用于从废水中高效地收集生物燃料，这在经济上和环境上都是可持续的。虽然目前存在将废水中的有机物质转化为生物燃料（如生物甲烷、生物乙醇和生物柴油）的技术，但这些生物燃料是不可使用的形式，如溶解气体或液体混合物，因此需要额外的提取步骤。一个潜在的溶液膜分离过程是节能的，需要一个小的环境足迹。然而，目前还没有有效的膜技术用于分离生产的生物燃料，因为低选择性和污染使得膜工艺效率低且成本高。******该提案解决了当前膜技术从废水中实现高效生物燃料收集的两个关键挑战：(1)低选择性和(2)严重污染。为了实现高选择性，将开发一种极耐湿的全疏膜。该膜将放置在进料溶液（生物燃料和废水混合物）和提取溶剂（对生物燃料具有高溶解度但对水溶解度低的有机溶剂）之间。溶解度差异驱使生物燃料作为气体进入萃取溶剂，而水由于在萃取溶剂中的溶解度差而被拒绝，从而导致生物燃料的高选择性。此外，将开发一种自清洁表面涂层，使用刺激反应材料，用于长期可持续的膜。在电压变化等外界刺激下，膜的表面涂层被破坏，膜表面沉积的污物被清除。作为一个潜在的应用，我们将展示从厌氧处理废水的流出物中长期可持续地收集生物甲烷。******开发的技术将大大增加可再生能源的供应，并减少温室气体（GHG）的排放。从经济上讲，废水中的甲烷可以补充加拿大居民区约21%的能源消耗。在环境方面，充分利用废水中的生物甲烷相当于去除加拿大50多万辆汽车排放的温室气体。从长远来看，拟议的研究项目将为水-食物-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.