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

项目编号：1236738机构：University of conn标题：将焦油转化为能量：分级孔结构的沸石催化裂解焦油本项目旨在通过一步催化过程将生物质气化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）的致癌性质，这使得它们不可能被处理，(c)通过将副产品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验证具有分层孔网络结构的沸石基材料将消除焦油中存在的重多环芳香族化合物碳氢化合物的扩散限制并适应其裂解的假设。此外，它们将为过渡金属的掺入提供开放的框架结构，这将增强所产生的轻质碳氢化合物向合成气的重整反应。本项目将重点研究各种具有孔网络和金属活性位点的微孔-介孔沸石的合成、表征和评价，这些沸石将促进重芳烃裂解和重整为合成气。对两种不同酸度、晶粒尺寸和硅铝比的沸石前驱体进行改性。采用可控脱硅途径和表面活性剂辅助方法，将介孔引入沸石中。采用湿浸渍法将各种过渡金属掺入到沸石的微孔/介孔表面。在实验室规模的固定床反应器中，将评价改性沸石裂解焦油并将其转化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相和气相分析技术将用于获得对焦油裂解和重整反应机理的基本认识。S的假设基于这样一种想法，即利用具有分层孔隙度的沸石和过渡金属的优势将是理想的，并将为将不需要的焦油转化为有价值的能源创造巨大的潜力。因此，本研究将通过以下方式做出根本性贡献：(a)发现并进一步表征分级孔沸石基材料，用于有效裂解焦油中存在的重烃；(b)鉴定轻烃重整为合成气的有效过渡金属；c)对焦油中多环芳烃的性质和反应性的认识。除了对生物燃料行业的技术影响外，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；c)它将吸引并给予来自财政困难地区的教师提升他们的专业素养的机会，并通过NSF Joule Fellow和da Vinci项目激励他们的小学后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.