CAREER: Manipulating Polarity to Enhance Hydrothermal Liquefaction of Biomass for Biofuels

职业：操纵极性以增强生物质的水热液化以生产生物燃料

• 批准号: 2144862
• 负责人: Jillian Goldfarb
• 金额: $ 55.49万
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-06-01 至 2027-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2144862&HistoricalAwards=false
• 关键词: CAREER; Manipulating; Polarity; Enhance; Hydrothermal

Cost-effective waste-to-energy technologies are critical components of a future green economy powered by renewable fuels. Hydrothermal liquefaction (HTL) transforms organic wastes into liquid biofuels by processing the waste in water at high temperature and pressure. One advantage of HTL over other biomass conversion techniques is that it directly treats wet wastes without an energy-intensive pre-drying step. To date, the majority of HTL research has explored the impact of process conditions on products generated from a range of biomass feedstocks. However, this research approach cannot overcome the primary challenges to widespread application of HTL for biofuels, namely that (1) product distributions cannot be accurately controlled or predicted, resulting in the need for significant downstream upgrading of the biocrude, and (2) the byproduct process water requires considerable treatment. These two challenges combine to make current large-scale HTL economically infeasible. The new approach to process design proposed in this project, however, could enable widespread implementation of HTL for wet waste to biofuel conversion. The production of such renewable fuels could help transform the U.S. into a green energy exporter and job opportunity creator. To fill such high-tech positions, a diverse workforce is needed. The Principal Investigator (PI) of this proposal has a strong track record training students from under-represented groups; at least one graduate student, one post-doctoral associate, and two undergraduate students will be trained as part of this work. The PI will develop a new course on Sustainable Engineering Design specifically aimed at encouraging and retaining women engineers. Garnering widespread public acceptance and support for policy initiatives promoting biofuels is critical to widespread deployment. To do this, the PI will conduct original survey research to benchmark public knowledge and opinion on biomass-based renewable fuels. Then, by incorporating results from the research into a first-of-its kind survey, the PI will uncover how scientists can best frame messages to increase public support for green energy technologies.Hydrothermal liquefaction (HTL) is a reactive and multiphase biomass conversion process producing supersaturated solutions of aqueous-organic mixtures and a separate organic biocrude phase. HTL process water (PW) contains organic molecules that are either insoluble or beyond their solubility limits, suggesting that as the dielectric constant of the HTL aqueous reaction media changes, it can create a supersaturated solution where sparingly soluble organics remain even after the PW is cooled. It is hypothesized that the selectivity and yields of HTL reactions are a function of this supersaturation degree, which is controlled by the dielectric constant and reaction enthalpies. To confirm and develop this concept, a new apparatus will be constructed to measure the dielectric constant of model molecules and mixtures at HTL-relevant conditions and solubilities of HTL intermediates and products. Using a Design of Experiments approach, the statistically significant relationships between dielectric constant and solubility parameter, and the selectivity and yields of HTL reactions will be explored. The accuracy of thermodynamic models used to predict the solubility of the organics in the aqueous phase and partitioning between the biocrude and organics phase will be improved by incorporating the dielectric constant and solubility measurements. Finally, the research team will investigate how organic compounds in the PW produced in the HTL process can be recovered through a combination of kosmotropic salting out and liquid-liquid extraction using a variety of salts with varying kosmotropic strength. Model HTL products will be examined individually at their solubility limits to estimate the maximum recoveries of each product as a first step towards estimating the separation selectivity in mixtures of these products. This work will lead naturally to the investigation of mixtures of model compounds to determine the degree to which these organics can form their own phase separate from the PW, and the abilities of kosmotropes to salt-out the organic products in a selective manner. This fundamental thermodynamic approach to HTL and product recovery could accelerate the transition to a renewable energy future by facilitating the design of more efficient and selective HTL processes. In addition to the advances made in terms of HTL, the Educational Component of this CAREER proposal will advance the way Introductory Environmental Engineering courses are taught to retain women and minorities in STEM.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.

具有成本效益的废物变能源技术是以可再生燃料为动力的未来绿色经济的关键组成部分。水热液化（HTL）通过在高温高压下处理水中的废物将有机废物转化为液体生物燃料。HTL与其他生物质转化技术相比的一个优点是，它直接处理湿废物，而无需能源密集型预干燥步骤。到目前为止，大多数HTL研究已经探索了工艺条件对由一系列生物质原料产生的产品的影响。然而，这种研究方法不能克服HTL用于生物燃料的广泛应用的主要挑战，即（1）不能准确地控制或预测产物分布，导致需要对生物原油进行显著的下游升级，以及（2）副产物工艺水需要相当大的处理。这两个挑战联合收割机使得目前的大规模HTL在经济上不可行。然而，本项目提出的新的工艺设计方法可以使湿废物转化为生物燃料的HTL得到广泛实施。这种可再生燃料的生产可以帮助美国转变为一个绿色能源出口国和就业机会创造者。为了填补这些高科技职位，需要多样化的劳动力。该提案的主要研究者（PI）在培训代表性不足的群体的学生方面有着良好的记录;作为这项工作的一部分，至少有一名研究生，一名博士后助理和两名本科生将接受培训。PI将开发一个关于可持续工程设计的新课程，专门旨在鼓励和留住女工程师。为推广生物燃料的政策举措争取公众的广泛接受和支持，是广泛使用生物燃料的关键。为此，PI将进行原始调查研究，以衡量公众对生物质可再生燃料的认识和意见。然后，通过将研究结果纳入首次调查，PI将揭示科学家如何最好地构建信息，以增加公众对绿色能源技术的支持。水热液化（HTL）是一种反应性多相生物质转化过程，产生含水有机混合物的过饱和溶液和单独的有机生物原油相。HTL工艺用水（PW）含有不溶或超出其溶解度极限的有机分子，这表明随着HTL水性反应介质的介电常数变化，它可以产生过饱和溶液，其中即使在PW冷却后也保留微溶有机物。假设HTL反应的选择性和产率是该过饱和度的函数，该过饱和度由介电常数和反应速率控制。为了证实和发展这一概念，一个新的装置将被构建来测量模型分子和混合物在HTL相关条件下的介电常数和HTL中间体和产物的溶解度。使用实验设计的方法，介电常数和溶解度参数之间的统计显着关系，HTL反应的选择性和产率将被探索。用于预测有机物在水相中的溶解度以及生物原油和有机物相之间的分配的热力学模型的准确性将通过并入介电常数和溶解度测量来改进。最后，研究小组将研究如何通过使用具有不同亲液强度的各种盐的亲液盐析和液-液萃取的组合来回收HTL工艺中产生的PW中的有机化合物。将在溶解度限度下单独检查模型HTL产品，以估计每种产品的最大回收率，作为估计这些产品混合物中分离选择性的第一步。这项工作将自然导致模型化合物的混合物的调查，以确定这些有机物可以形成自己的相分离的PW的程度，和kosmotropes的能力，以选择性的方式盐析的有机产品。HTL和产品回收的基本热力学方法可以通过促进更高效和选择性HTL工艺的设计来加速向可再生能源未来的过渡。除了在HTL方面取得的进展外，该CAREER提案的教育部分将推进环境工程入门课程的教学方式，以留住STEM中的女性和少数民族。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估来支持。