Collaborative Research: High Surface Area Mesoporous Carbons for Facile Biofuel Recovery from Dilute Aqueous Solution

1159295/1159200 Vogt/Nielsen尽管在从可再生生物质资源生产可持续液体运输燃料方面取得了重大进展，但最终产品毒性仍然是大多数传统生物工艺中的关键生产力限制因素。减轻生物燃料产品毒性的一种有效方法是通过从培养物中原位回收生物燃料产品，这需要低成本、低能量和生物相容性分离技术，其选择性地从稀水溶液中除去生物燃料。低能分离工艺已经被提出，但大多数之前的研究都集中在模型、生物燃料-水解决方案上;真实的工艺受到复杂生物混合物的挑战，这些混合物容易引起结垢和材料生物相容性差，从而对分离性能和整体工艺可行性产生不利影响。在这里，我们建议系统地研究磁性，介孔，碳基材料，以阐明基本的物理化学性质如何影响吸附剂性能的生物燃料（乙醇和正丁醇）回收在理想化的解决方案和不断增长的文化。生物燃料-吸附剂相互作用以及非理想相互作用（结垢现象）的基本和机理表征将提供真实的系统中的结构-功能关系。最终，通过将这些材料与生产生物燃料的微生物培养物相结合，将评估通过连续原位生物燃料回收可以实现的生产力提高。有序介孔材料的高比表面积和孔可及性使其在生物燃料分离方面具有吸引力。我们建议利用软模板介孔碳作为生物燃料吸附剂;孔径、表面积和孔形态的合成调整将提供对这些性质如何影响生物燃料吸附能力、分配系数和吸附热的基本理解。我们提出了一种单锅合成法，在碳中包含钴纳米颗粒，而不会显著影响介观结构，从而能够从培养物中磁性分离吸附剂。将系统地检查回收效率，以确定磁性分离是否是吸附剂回收的可行机制。我们将开始基础研究，使用模型解决方案与其他常用的生物燃料分离吸附剂进行直接比较;然而，在真实的应用中，其他考虑因素将至关重要。实际上，生产生物燃料的培养物是复杂的混合物，其中结垢和其他非理想的相互作用导致分离性能改变。同时，介孔碳的微生物生物相容性相对未知。因此，我们将系统地研究非理想相互作用的性质和程度，以定义和纳入材料特性，从而在实际工艺条件下促进持续性能。两种不同的回收策略将被开发和检查的比较分析：一个传统的，外部循环的填充床柱，和新的分散的磁性吸附剂颗粒在整个文化（其次是他们的磁性收集）。我们预计，后一种新方法（从未在生长的生物燃料生产培养物中进行过研究）将提供改善的功效，因为它能够使吸附剂和培养基之间连续接触，而无需昂贵和细胞损伤的泵送要求。这种端到端的概念验证研究将能够评估吸附剂的物理特性如何影响应用于从生长的微生物培养物中连续原位去除乙醇和正丁醇的性能。这些顶点实验独特地允许直接评估在理想化条件下执行的基本表征是否以及如何预测真实的系统中的性能。对用于生物燃料吸附的介孔材料的性质-结构关系的基本理解将使生物燃料从培养液中更有效地分离，并将有助于减少美国对外国化石燃料的依赖。更广泛的教育影响将涉及研究生和本科生参与这一高度跨学科的调查领域。此外，这项研究的概念和结果将被纳入关于生物反应器和生物燃料的新教学实验室模块。建议向当地代表性不足的K-12学生开展外联活动，讨论生物燃料的社会重要性及其分离和生产相关的挑战;此外，这些活动旨在纠正有关纳米技术的常见误解。将通过阿克伦全球聚合物学院向P-16进行更广泛的传播，该学院在全球范围内具有影响力。

1159295/1159200Vogt/NielsenDespite significant developments in producing sustainable liquid transportation fuels from renewable biomass resources, end-product toxicity remains a key, productivity-limiting factor in most conventional bioprocesses. One effective approach to relieve biofuel product toxicity is through its in situ recovery from the culture, which requires low cost, low energy, and biocompatible separation technologies that selectively remove biofuels from dilute aqueous solutions. Low energy separation processes have been proposed, but most prior studies have focused on model, biofuel-water solutions; real processes are challenged by complex biological mixtures prone to cause fouling and poor material biocompatibility, which adversely impact separation performance and overall process viability. Here, we propose to systematically examine magnetic, mesoporous, carbon-based materials to elucidate how fundamental physicochemical properties impact adsorbent performance for biofuel (ethanol and n-butanol) recovery in both idealized solutions and growing cultures. Fundamental and mechanistic characterizations of biofuel-adsorbent interactions, as well as nonideal interactions (fouling phenomena), will provide structure-function relationships in real systems. Ultimately, the productivity enhancements that can be realized through continuous, in situ biofuel recovery will be assessed by integrating these materials with biofuel-producing microbial cultures. High surface area and pore accessibility of ordered mesoporous materials make them attractive for biofuel separations. We propose to utilize soft templated mesoporous carbons as biofuel adsorbents; synthetic tuning of the pore size, surface area, and pore morphology will provide a fundamental understanding of how these properties impact biofuel adsorption capacity, partition coefficients, and heats of adsorption. We propose a single pot synthesis to include cobalt nanoparticles in the carbon without significantly impacting the mesostructure to enable magnetic separation of the adsorbent from culture. Recovery efficacy will be systematically examined to determine if magnetic separation is a viable mechanism for adsorbent recovery. We will begin with fundamental studies using model solutions for direct comparison with other commonly examined adsorbents for biofuel separations; however, additional considerations will be critical in real applications. In reality, biofuel-producing cultures are complex mixtures wherein fouling and other non-ideal interactions lead to altered separation performance. Meanwhile, the microbial biocompatibility of mesoporous carbons is relatively unknown. Accordingly, we will systematically examine the nature and degree of non-ideal interactions to define and incorporate material properties promoting sustained performance under realistic process conditions. Two different recovery strategies will be developed and examined for comparative analysis: a traditional, externally circulated packed-bed column, and the novel dispersion of magnetic adsorbent particles throughout the culture (followed by their magnetic collection). We anticipate the latter novel approach, which has never been examined in growing, biofuel-producing cultures, will provide improved efficacy as it enables continuous contact between the adsorbent and culture medium without costly and cell-damaging pumping requirements. This end-to-end, this proof-of-concept study will enable evaluation of how adsorbent physical properties impact performance as applied to continuous, in situ removal of ethanol and n-butanol from growing microbial cultures. These capstone experiments uniquely allow direct evaluation of if and how fundamental characterizations performed under idealized conditions can predict performance in real systems. A fundamental understanding of the property-structure relationships of mesoporous materials for biofuel adsorption would enable more efficient separations of biofuels from culture broths and will aid in reducing the U.S. dependence on foreign fossil fuels. The broader educational impact will involve participation of graduate and undergraduate students in this highly interdisciplinary area of inquiry. Moreover, concepts and results from this research will be incorporated into a new teaching lab module on bioreactors and biofuels. Outreach activities to local underrepresented K-12 students are proposed to discuss the societal importance biofuels and the challenges associated with their separation and production; additionally, these activities will aim to correct common misconceptions regarding nanotechnology. Broader dissemination to P-16 will be enabled through the Akron Global Polymer Academy, which has worldwide reach.