Turning Tars into Energy: Zeolites with Hierarchical Pore Structure for the Catalytic Cracking of Tars

主要研究者：Valla，Ioulia提案编号：1236738机构：康涅狄格大学题目：将焦油转化为能源：具有分级孔结构的沸石用于焦油的催化裂解该项目旨在使用一步催化工艺将生物质气化产生的合成气中的废焦油化合物转化为有价值的气体。这项研究的重要性是由三个重要因素驱动的：（a）焦油在下游气化过程中的有害影响，（B）焦油（多环芳烃）的生碳性质，这使得它们的处置是不可能的，以及（c）通过将副产物转化为有价值的产品来提高整个生物质气化过程的效率的潜力。本研究的主要目的是测试具有分级孔网络结构的沸石基材料将消除焦油中存在的重质多环芳烃化合物烃的扩散限制并将容纳其裂化的假设。此外，它们将为过渡金属的引入提供开放的骨架结构，这将增强所产生的轻质烃到合成气的重整反应。本项目将集中于具有孔网络和金属活性中心的各种微孔-中孔沸石的合成、表征和评估，这将增强重芳烃到合成气的裂化和重整。对具有不同酸度、不同晶粒尺寸和不同硅铝比的两种沸石前驱体进行改性。通过控制脱硅途径和表面活性剂辅助的方法可以在沸石中引入介孔结构。采用湿浸渍法将各种过渡金属引入到沸石的微/介孔表面。在实验室规模的固定床反应器中评价改性沸石裂解焦油并随后改革为有价值的合成气的有效性。模型化合物将用于模拟焦油的复杂混合物。先进的材料表征和液体和气体分析技术将被用来获得焦油的裂解和重整反应机理的基本认识。的假设基于这样的想法，即利用具有分级孔隙率和过渡金属的沸石的优点将是理想的，并且将产生将不需要的焦油转化为有价值的能量的巨大潜力。因此，本研究将通过以下方面做出基本贡献：（a）发现和先进表征用于焦油中存在的重质烃的有效裂解的分级孔沸石基材料;（B）鉴定用于轻质烃重整为合成气的有效过渡金属;和c）理解焦油中存在的多环芳烃的性质和反应性。除了对生物燃料工业的技术影响外，该项目还将产生教育影响：a）它将有助于本科生和研究生的教育; B）它将在夏季通过NSF RET计划为高中生提供为期一周的工程技术介绍;及c）吸引并给予来自财政困难地区的教师机会，提升他们的专业水平，并刺激他们的职位，通过NSF焦耳研究员和达芬奇计划，小学生在大学里接受工程教育。

PI: Valla, IouliaProposal Number: 1236738Institution: University of ConnecticutTitle: Turning Tars into Energy: Zeolites with Hierarchical Pore Structure for the Catalytic Cracking of TarsThis project aims at conversion of waste tars compounds in synthesis gas derived from biomass gasification, into valuable gases using one step catalytic process. The importance of this research is driven by three significant factors: (a) the detrimental effect of tars in downstream gasification processes, (b) the carginogenic nature of tars (multi-ring aromatic hydrocarbons), which makes their disposal impossible and (c) the potential to increase the efficiency of the overall biomass gasification process by transforming byproducts to valuable products. The key objective this research is to test the hypothesis that zeolite-based materials with hierarchical pore network architecture will eliminate the diffusion limitations of the heavy multi-ring aromatic compounds hydrocarbons present in tars and will accommodate their cracking. Moreover, they will provide the open framework structure for the incorporation of transition metals, which will enhance the reforming reactions of the produced lighter hydrocarbons to synthesis gas.This project will focus on the synthesis, characterization and evaluation of various microporous-mesoporous zeolites with pore network and metal active sites that will enhance the cracking and reforming of heavy aromatic hydrocarbons to synthesis gas. Two types of zeolite precursors with different acidity, crystal size and Si/Al ratios will be modified. Mesoporosity will be introduced in the zeolites by employing controlled desilication pathways and surfactant assisted method. Various transition metals will be incorporated in the micro/mesoporous surface of the zeolites using wet impregnation method. The effectiveness of the modified zeolites to crack and subsequently reform the tars into valuable synthesis gas will be evaluated in laboratory-scale fixed bed reactor. Model compounds will be used to simulate the complex mixture of the tars. Advanced materials characterization and liquid and gas analysis techniques will be used to gain fundamental understanding of the cracking and reforming reaction mechanism of tars.PI?s hypothesis lies on the idea that utilizing the advantages of zeolites with hierarchical porosity and transition metals would be ideal and would create great potential for transforming the unwanted tars to valuable energy. Thus, this research will make fundamental contributions via: (a) the discovery and the advanced characterization of hierarchical pore zeolite-based materials for the effective cracking of heavy hydrocarbons present in tars; (b) the identification of effective transition metals for the reforming of light hydrocarbons to synthesis gas; and c) the understanding of the nature and the reactivity of multi-ring aromatic hydrocarbons present in tars. In addition to the technological impact on the biofuel industry, this project will also have educational impact: a) it will contribute to the education of both undergraduate and graduate students; b) it will bring high school students during the summer for a one-week-long introduction to engineering technologies through the NSF RET program; and c) it will attract and give the opportunity to teachers from districts with financial challenges to elevate their professional carrier and to stimulate their post-elementary students to pursue an engineering education in college through the NSF Joule Fellow and da Vinci programs.