Study of particulate systems -powders and granules- in reactive and non-reactive environments

拟议的研究旨在研究颗粒物系统(粉末和颗粒)在以下情况下的行为：1.在没有化学反应的环境中的微米、非曝气颗粒流。这项工作包括：(A)研究颗粒混合物无曝气流动(重力驱动的流动床)过程中的径向和轴向速度以及浓度分布；(B)发展关于颗粒混合物中的流动特性与分离趋势的知识。所提出的方法旨在通过评估流动过程中混合物中的分散趋势来测量分离。纳米颗粒分散体在存在或不存在第三种(气态)相的情况下，作为催化剂或反应物存在于液体(浆体)中。研究(A)三相浆态费托合成反应器中的纳米催化剂(纳米碳化铁)和(B)用于重整和加氢处理的两相固定床反应器中的负载型纳米金属催化剂。多相反应器是多步过程的典型代表，所提出的工作具有原创性、多维性，在基础和应用层面上都具有重要意义。了解纳米催化剂的物理化学行为将极大地提高我们设计此类催化系统和优化生产率的能力，同时降低成本和工业生产过程对环境的影响。

The proposed research is aimed at studying the behaviour of particulate systems (powders and granules) in the following contexts:1. Micrometric, non-aerated particulate flows in environments without chemical reactions. The work includes (a) the study of radial and axial velocity as well as concentration profiles during non-aerated flow of particulate mixtures (mobile beds driven by gravity); (b) the development of knowledge relating flow characteristics to segregation tendencies in particulate mixtures. The proposed method is intended to measure segregation by evaluating dispersion tendencies in mixtures during flow.2. Nanometric particulate dispersions in liquid phases (slurries), acting as catalysts or reactants, in the presence or absence of a third (gaseous) phase. Investigate (a) nanometric catalysts (nano-iron carbides) in 3-phase slurry Fischer-Tropsch Synthesis reactors and (b) supported nanometric metallic catalysts, in 2-phase, fixed-bed reactors for reforming and hydrotreatment. Multi-phase reactors are typical examples of multi-step processes.The proposed work is original, multi-dimensional and it is highly significant, both at the fundamental and applied levels. Understanding the physico-chemical behaviour of nanocatalysts will greatly improve our capacity to design such catalytic systems and optimize productivity while decreasing costs and the environmental impact of industrial production processes.