Development of a packed bed reactor for carbon nanotube synthesis

摘要：碳纳米管（CNTs）是未来最具吸引力的材料之一，可用于从结构建筑到超导体的一系列应用。碳纳米管的机械、电学和热学性能在纳米尺度上优于铜、铝和钢等常用材料。然而，在工业规模上制造纳米材料存在一些问题和问题。在纳米尺度上发现的性质并不能转化为宏观尺度，它们的合成是非常耗能的。此外，围绕目前在学术界和工业小实验室规模使用的合成技术存在问题。浮式催化剂化学气相沉积（FC-CVD）是最有前途的工业规模化途径之一，但存在反应器密度和碳转化率等问题。两者都需要改进，以使过程变得可行。这一建议将解决理解气凝胶形成的所有物种的浓度问题。分析纳米颗粒在反应器内轴向和径向分布的方法将通过气溶胶收集技术进行。一旦基本的反应动力学和化学相关物质的浓度都被知道和理解，反应将被放入一个更高反应密度的反应器中。本研究的数据将用于模拟反应器内的气溶胶动力学，并与计算流体动力学模型相结合。此外，本提案将概述设计和创建一个伪填充床反应器，其中催化剂前体被输送到碳分解成后续自由基的点。反应器的设计和建造包括使用的所有材料，将密切关注为高质量碳纳米管的大规模生产提供解决方案。

Abstract: Carbon nanotubes (CNTs) are one of the most attractive materials of the future that can be used in a range of applications from structural buildings to use in super-conductors. Commonly used materials such as copper, aluminium and steel are outperformed by CNT's mechanical, electrical and thermal properties on the nanoscale relative to their density. However, there are problems and issues that come from manufacturing nanomaterials on an industrial scale. The properties that are found on the nanoscale do not translate to the macro scale and their synthesis is very energy intensive. Further, there are issues surrounding current synthesis techniques which are used in academia and on small laboratory scales in industry. Floating catalyst chemical vapour deposition (FC-CVD) is one of the most promising routes for industrial scale-up however, there are issues concerning the reactor density and the carbon conversion. Both require an improvement in order for the process to become feasible.This proposal will address the issue of understanding the concentration of all species at which aerogel forms. The methods to analyse the distribution of nanoparticles within the reactor both axially and radially will be performed via aerosol collection techniques. Once the fundamental reaction kinetics and concentrations of the chemically relevant species are both known and understood, the reaction will be put into a higher reaction density reactor. The data from this study will be used for modelling aerosol dynamics within the reactor and coupled with computational fluid dynamics model.Further, this proposal will outline the design and creation of a pseudo packed bed reactor in which the catalyst precursors are delivered to the point at which the carbon has broken down into subsequent radicals. The reactor design and build including all materials used, will focus closely on providing a solution to the mass production of high quality carbon nanotubes.