Oxidation of n-butane to maleic anhydride in a milli-structured fixed-bed reactor

将以正丁烷选择性氧化制马来酸酐为例，研究微结构或微结构固定床反应器的概念，作为具有工业意义的强放热、多相催化反应的例子。与传统反应器相比，该反应器具有较短的扩散长度和较高的平均温度，因此在催化活性和选择性方面可以得到加强。与具有催化剂涂层壁的微结构反应器相比，固定床概念允许使用工业上经过验证的催化材料和简单的废催化剂交换。该项目的目的是通过实验和理论研究确定反应堆规模扩大的基础。为此，将对不同几何形状的固定床和不同尺寸的催化剂颗粒进行转化、产品分布和压降的系统测量。此外，停留时间分布测量是必要的，以研究在低通道和催化剂颗粒直径比下可能的壁面效应。通过使用格-玻尔兹曼方法等现代计算技术对固定床内的流动、反应和传热进行详细的数值模拟，增强了设计和放大工程模型的制定。如果项目目标能够实现，计划继续进行项目，目标是实现微结构固定床的中试规模。

The concept of micro- or milli-structured fixed-bed reactors shall be investigated with the selective oxidation of n-butane to maleic anhydride as an example of a strongly exothermic, heterogeneously catalyzed reaction with industrial relevance. It is expected that the process can be intensified regarding catalytic activity and selectivity in such a reactor because of lower diffusion lengths and higher average temperatures than in conventional reactors. In contrast to micro-structured reactors with catalyst coated walls, the fixed-bed concept allows for the use of industrially proven catalytic materials and simple exchange of spent catalysts. Aim of the project is to determine the basis for a reactor scale-up through experimental and theoretical investigations. For this purpose, systematic measurements of conversion, product distribution, and pressure drop with fixed beds of different geometries and catalyst particles with variable size will be done. Additionally, residence time distribution measurements are necessary to investigate possible wall effects at low ratios of channel and catalyst particle diameter. The formulation of engineering models for design and scale up is enhanced by detailed numerical simulations of flow, reactions and heat transfer in the fixed bed using modern computational techniques such as the lattice-Boltzmann method. If the project goal can be reached, it is planned to continue the project with the aim of realizing a milli-structured fixed-bed at pilot scale.