ECO-CBET: GOALI: Condensing water from the air for building dehumidification and decarbonization using thermo-responsive desiccants

2318720（双）。管理建筑物的湿度对于保持居住者的舒适度、减少对湿度敏感的制造中的缺陷（例如，半导体），并防止食品保存中的食源性病原体。现有的加热、通风和空调（HVAC）系统依赖于冷表面冷凝或吸湿材料作为干燥剂来从空气中去除水分。然而，这是一个能量效率低的过程，因为足够的水分冷凝所必需的低温设定点和克服蒸汽中显著的蒸发焓所需的额外能量。目前，仅建筑物的湿度控制每年就产生6亿吨二氧化碳。因此，高效的空气净化器是减少能源使用和温室气体排放的绝佳机会，以促进可持续发展和脱碳运动，并应对气候变化。这个融合项目的愿景是启动和建立高效的冷凝系统，通过在建筑可持续性，热运输，土木工程和化学工程方面的合作和跨学科努力，直接从空气中冷凝水。这项促进更高效建筑节能的基础研究将直接有益于国民健康和国家制造业。此外，该研究与大学生和早期职业科学家的跨学科环境研究培训紧密结合，这将有利于STEM劳动力。该项目采用具有温度依赖性吸附等温线的热响应（TR）干燥剂，利用低于和高于低临界溶解温度（LCST）的热响应可切换亲水性，吸附容量高。此外，TR干燥剂的热响应性打破了传统干燥剂对水的固定亲和力，这允许以液体形式释放水，并避免了传统干燥剂在再生期间水蒸发的高能量需求。该项目将（1）开发具有可调LCST和不同干燥条件下最佳温度依赖吸附等温线的耐用TR干燥剂，（2）通过建模和实验验证优化设计参数来提高TR干燥剂轮的传热和传质速率，（3）开发以液体形式去除吸附水的技术，以及（4）通过执行硬件在环（HIL）实验来评估TR除湿轮在除湿系统中的效率。建议TR干燥剂轮与温度相关的吸附等温线导致低再生温度和潜在的旁路蒸发热。在再生过程中以液体形式解吸吸附的水分的独特性能与HVAC应用中的传统方法相比节省了高达6倍的能源，从而节省了高达30%的碳排放。此外，空气中的冷凝水可以被收集并用于缓解干旱气候下建筑运营中的水资源短缺。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

2318720 (Shuang). Managing the humidity of buildings is essential for maintaining occupant comfort, reducing defects in moisture-sensitive manufacturing (e.g., semiconductors), and preventing foodborne pathogens in food preservation. Existing Heating, Ventilation, and Air-conditioning (HVAC) systems rely on either cold surface condensation or hygroscopic materials as desiccants to remove moisture from air. However, this is an energy-inefficient process due to the low-temperature setpoint essential for sufficient moisture condensation and the extra energy required to overcome significant enthalpy of vaporization in dehumidification. Currently, humidity control in buildings alone is responsible for 600 million tons of CO2 annually. Hence, efficient air dehumidification represents an excellent opportunity to reduce energy use and greenhouse gas emissions to facilitate the sustainability and decarbonization movement and counteract climate change. The vision of this convergent project is to initiate and establish high-efficiency dehumidification systems that directly condense water from the air through collaborative and interdisciplinary efforts in building sustainability, thermal transport, civil engineering, and chemical engineering. This fundamental research promoting more efficient building dehumidification will directly benefit national health and national manufacturing. Furthermore, the research is closely integrated with interdisciplinary environmental research training for college students and early-career scientists, which will benefit the STEM workforce.This project pursues energy-efficient dehumidification utilizing Thermo-Responsive (TR) desiccants with temperature-dependent adsorption isotherms—benefiting from the thermo-responsive switchable hydrophilicity below and above the Lower Critical Solution Temperature (LCST)—and high adsorption capacity. In addition, the thermo-responsiveness of TR desiccants breaks traditional desiccants’ fixed affinity to water, which allows for the release of water in liquid form and avoids the high energy requirements of water vaporization in traditional desiccants during the regeneration. The project will (1) develop durable TR desiccants with tunable LCSTs and optimum temperature-dependent adsorption isotherms for different dehumidification conditions, (2) improve the heat and mass transfer rate of TR desiccant wheels by optimizing the design parameters through modeling and experimental validation, (3) develop techniques to remove the adsorbed water in liquid form, and (4) evaluate the efficiency of the TR desiccant wheel in the dehumidification system by performing a hardware-in-the-loop (HIL) experiment. The proposed TR desiccant wheel with temperature-dependent adsorption isotherms leads to low regeneration temperatures and the potential to bypass the heat of evaporation. The unique property of desorbing the adsorbed moisture in the liquid form during the regeneration saves up to 6x energy compared to traditional approaches in HVAC application, which saves up to 30% carbon emission. Moreover, condensed water from the air can be collected and used to alleviate water scarcity in building operations in arid climates.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.