SusChEM: Waste Valorization through Hydrothermal Catalytic Conversion of Carboxylic Acids/Esters to Hydrocarbon Fuels

[14][18]李建平，刘建平，李建平，等。水热催化羧酸/酯转化为烃类燃料的研究。人口增长和经济发展刺激了对新能源和化学前体的需求，同时也产生了越来越多的废物。同时，越来越多的人认为，废物流应被视为宝贵的可再生资源，而不是经济负担。目前的废水处理操作是能源密集型的，在美国，约3%的电能用于废水处理，尽管废水中含有(1)有机物质，其能量是处理所需能量的数倍，(2)可作为培养多倍有机生物质的来源的营养物质（例如，通过藻类培养）。从生物精炼厂的概念来看，单个工艺流的价值最大化，废水处理提供了在满足处理目标的同时生产能源和有价值的化学品的机会。环境工程师具有独特的定位，在评估废物流，开发满足环境质量目标的新技术，同时回收和生产能源，平台化学原料和营养物质方面发挥核心作用。该项目的总目标是推进水热催化技术，将废物衍生的羧酸/酯原料转化为碳氢化合物燃料。发展经济的废物流增值技术对改变废物处理方法具有重大的潜力。改进的转化水中生物质衍生有机物的技术也将对新兴的木质纤维素和藻类生物精炼工业产生更广泛的影响，在这些工业中，原料脱水/干燥是经济可行性的主要障碍。该项目将有助于培训至少两名研究生，并将用作招募和指导代表性不足的少数民族本科研究人员的工具。此外，项目参与者将为I在大学指导的高中女生环境工程和可持续发展营做出贡献。拟议的工作支持更大的合作努力，目标是开发综合生物催化途径，这些途径可能对城市、农业和工业废物流（包括预计来自拟议的纤维素生物精炼厂的大量有机废物）的增值产生革命性影响。原料在水中的转化是理想的，因为它消除了成本和能源高昂的脱水/干燥步骤的需要。这项研究将是第一个集中于开发催化剂的研究之一，该催化剂既能持续有效地对废物产生的羧酸/酯进行脱氧，又能就地生产氢气以满足工艺需要。拟议的工作还将提高对催化剂失活机制的理解，并确定维持催化剂活性的预防和再生策略。概述了一系列的任务，包括研究具有不同低成本的初级和次级金属组合的催化剂，并比较它们的双重功能（酸/酯脱氧和原位制氢）。最有前途的催化剂配方将被广泛地表征，它们的活性、寿命和失活机制将在填充床反应器的连续流动条件下与模型化合物和废物来源的原料进行详细研究。实验结果将用作技术经济和生命周期分析的投入，以评价价值增值潜力和环境可持续性。

1438218PI: Strathmann, Timothy J.SusChEM: Waste Valorization through Hydrothermal Catalytic Conversion of Carboxylic Acids/Esters to Hydrocarbon FuelsPopulation growth and economic development are spurring increases in demand for new sources of energy and chemical precursors while simultaneously producing growing quantities of waste. Concurrently, there is growing agreement that waste streams should be viewed as valuable renewable resources rather than economic burdens. Current wastewater treatment operations are energy intensive, and ~3 % of electrical energy in the U.S. is used for wastewater treatment despite the fact that wastewater contains (1) organic materials possessing several times the energy needed for treatment, and (2) nutrients that can be used as a source to cultivate many times more organic biomass (e.g., through algae cultivation). When viewed in a biorefinery concept where the value of individual process streams is maximized, wastewater treatment provides an opportunity to produce energy and valuable chemicals while meeting treatment goals. Environmental engineers are uniquely positioned to play a central role in valorizing waste streams, developing new technologies that meet environmental quality goals while simultaneously recovering and producing energy, platform chemical feed stocks, and nutrients. The overall objective of the project is to advance hydrothermal catalytic technologies for converting waste-derived carboxylic acid/ester feed-stocks to hydrocarbon fuels. Development of economical technologies for valorizing waste streams has significant potential to transform waste treatment practices. Improved technologies for conversion of biomass-derived organics in water would also have broader impacts for the nascent lignocellulosic and algal biorefining industries, where feedstock dewatering/drying is a major hurdle to economic viability. This project will contribute to the training of at least two graduate students and will be used as a vehicle for recruiting and mentoring underrepresented minority undergraduate researchers. In addition, project participants will contribute to an environmental engineering and sustainability camp for high school girls that the I directs, at the University.The proposed work supports larger collaborative efforts targeting development of integrated biological-catalytic pathways that are potentially transformative for valorization of municipal, agricultural, and industrial waste streams, including large quantities of organic wastes expected from proposed cellulosic biorefineries. Conversion of feedstocks in water is ideal because it eliminates the need for cost- and energy-prohibitive dewatering/drying steps. This study will be one of the first to focus on developing catalysts capable of sustained activity for both deoxygenation of waste-derived carboxylic acids/esters and in situ production of hydrogen to meet process needs. Proposed work will also improve understanding of the mechanisms responsible for catalyst deactivation and identify preventative and regeneration strategies for sustaining catalyst activity. A series of tasks were outlined to include examine catalysts with different combinations of lower-cost primary and secondary metals and to be compared for their dual functionality (acid/ester deoxygenation and in situ hydrogen generation). The most promising catalyst formulations will be extensively characterized, and their activity, longevity and deactivation mechanisms will be studied in detail under continuous-flow conditions in a packed bed reactor with both model compounds and waste-derived feedstock?s. Experimental results will be used as input for techno-economic and life cycle analyses to evaluate valorization potential and environmental sustainability.