Development of a packed bed reactor for carbon nanotube synthesis

摘要：碳纳米管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。通常使用的材料，如铜、铝和钢，由于碳纳米管在纳米尺度上的机械、电学和热学性能相对于它们的密度，表现得更好。然而，在工业规模制造纳米材料的过程中也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到宏观尺度上，而且它们的合成是非常耗能的。此外，目前学术界和工业上小规模实验室使用的合成技术也存在一些问题。浮动催化剂化学气相沉积(FC-CVD)是最有希望实现工业放大的方法之一，但存在着反应器密度和碳转化率等问题。两者都需要改进才能使这一过程变得可行。这项建议将解决了解形成气凝胶的所有物种的浓度的问题。分析反应堆内纳米颗粒在轴向和径向分布的方法将通过气溶胶收集技术进行。一旦基本反应动力学和化学相关物种的浓度都已知和了解，反应将被放入更高反应密度的反应器中。这项研究的数据将用于模拟反应器内的气溶胶动力学，并与计算流体力学模型相结合。此外，该提案将概述一种伪填充床反应器的设计和创建，在该反应器中，催化剂前体被输送到碳已分解为后续基团的点。反应堆的设计和建造，包括所有使用的材料，将密切关注于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.