EAGER: A Novel Multi-Tray Dry Biofilm Reactor for Methane Capture from Air

最近的研究表明，与工业化前地球表面温度相比，甲烷(CH4)对目前观测到的1.1摄氏度的全球变暖贡献了大约0.5摄氏度。因此，现在人们普遍认为，到2050年，减少甲烷排放应该是减缓全球变暖的关键重点。据预测，到2050年，消除3亿吨大气中的甲烷可以使全球变暖减少0.1-0.2摄氏度，这一幅度将对地球气候产生积极影响。然而，这种程度的减少将需要直接从大气中去除甲烷，这一过程还不存在可扩展的技术。为了填补这一空白，研究小组提议开发和验证一种新颖的、概念验证的多托盘生物膜反应器，该反应器可以在当地甲烷浓度为500-5000 ppm的地区(如垃圾填埋场、粪便泻湖或废水处理厂)直接从空气中捕获甲烷，并将甲烷转化为一种有价值的产品：动物饲料蛋白质。尽管正在开发多种转化点源甲烷的技术(例如，含有10~40%甲烷的天然气或沼气)，但在经济上还没有可行的技术来捕获500-5000 ppm的甲烷。这项研究计划将专注于开发一种多塔板高反应表面“干式”生物膜反应器，为解决水中溶解度低的气体基质的水基生物转化所固有的根本挑战提供一种新的解决方案。这项研究计划将增进对大气CH4生物膜转化能力的理解，这是一种温室气体(GHG)，目前相对于工业化前的全球表面温度，目前贡献了约0.5摄氏度的全球变暖。这项研究将首次验证使用直接从空气中捕获的甲烷生产单细胞蛋白质(SCP)的潜力，并将对拟议技术的经济可行性和环境影响进行定量评估。如果成功，建议的生物膜反应器将是第一个这样的设计，能够可持续地从空气中捕获甲烷，当地甲烷浓度在500至5000 ppm之间，并通过将其加入动物或水产养殖饲料中实现较长期的CH4封存作为SCP，进一步减少温室气体排放。这种生物膜反应器的模块化设计将有助于扩大温室气体产生率不同的地点的规模。如果成功，这项拟议的技术有可能有助于减缓全球变暖，帮助实现到2050年消除3亿吨大气CH4的雄心勃勃但必要的目标，避免全球变暖0.1-0.2摄氏度。此外，这项研究将为其他天然气基质(如页岩气、合成气和沼气)的生物膜转化打开大门，绕过与低水溶解度天然气基质生物转化相关的挑战。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Recent studies have shown that methane (CH4) contributes approximately 0.5ºC of the observed 1.1ºC present-day warming relative to the Earth’s pre-industrial global surface temperature. As a result, it is now broadly accepted that abatement of CH4 emissions should be a critical focus for slowing global warming by 2050. It is predicted that removal of 300 million tons of atmospheric CH4 can reduce global warming by 0.1-0.2ºC by 2050, a magnitude that would have a positive impact on the planet’s climate. However, a decrease of this magnitude will require removal of CH4 directly from the atmosphere, a process for which no scalable technology exists. To fill this gap, the research team proposes to develop and validate a novel, proof-of-concept multi-tray biofilm reactor that can directly capture CH4 from the air in areas with local CH4 concentrations of 500-5000 ppm, such as landfills, manure lagoons, or wastewater treatment plants, and that will convert the CH4 to a valuable product: protein for animal feed. Although multiple technologies are under development for converting point-source CH4 (e.g., natural gas or biogas with 10~40% CH4), no economically feasible technology exists to capture CH4 in the 500-5000 ppm range. This research program will focus on developing a multi-tray high-reaction-surface “dry” biofilm reactor that offers a novel solution to addressing the fundamental challenges inherent to aqueous bioconversion of gas substrates that have low solubility in water. This research program will advance understanding of the capability of biofilm-based conversion of atmospheric CH4, a greenhouse gas (GHG) that currently contributes approximately 0.5ºC of the present-day warming relative to the pre-industrial global surface temperature. This research will validate, for the first time, the potential of producing single-cell proteins (SCP) using CH4 captured directly from the air and will provide a quantitative estimate of the economic feasibility and environmental impact of the proposed technology. If successful, the proposed biofilm reactor will be the first such design capable of sustainably capturing CH4 from the air with local CH4 concentration ranging from 500 to 5000 ppm and achieving longer term CH4 sequestration as SCP by incorporating it in animal or aquaculture feed, further reducing the emission of GHG. The modular design of this biofilm reactor will facilitate scale-up for sites of varying GHG production rates. If successful, the proposed technology has the potential to contribute to slow global warming, assisting in achieving the ambitious, but necessarily, goal of 300 million tons of atmospheric CH4 removal by 2050, averting 0.1-0.2°C of global warming. Additionally, this research will open doors to the biofilm-based conversion of other gas substrates (e.g., shale gas, syngas, and biogas), by circumventing the challenges associated with the bioconversion of gas substrates with low aqueous solubilities.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.