催化剂颗粒形状对甲烷水蒸气重整反应的影响及工业反应器模拟

Influence of catalyst shape on methane steam reforming and simulation of industrial reactor

甲烷水蒸气重整工艺是现阶段最主要的工业制氢技术,催化剂颗粒形状和反应器操作条件是影响重整反应器性能和产物组成的重要因素。首先从颗粒尺度研究催化剂形状对甲烷水蒸气重整反应的影响,在不同的反应温度和压力下,计算并比较了球形、柱形和环形催化剂的效率因子,其大小顺序为:柱形<球形<环形。其次,将反应器床层的质量、热量和动量传递与环形催化剂颗粒的扩散-反应方程相结合,建立了用于描述甲烷水蒸气重整工业反应器的一维轴向数学模型。计算并分析了反应器进口温度和压力对反应器床层的温度和压力分布、催化剂效率因子以及甲烷转化率和各组分浓度分布的影响,确定了适宜的工业反应器进口温度和压力,分别为773 K和3 MPa。

Methane steam reforming（MSR） is the most widely used technology for hydrogen production in industry now, where the shape of catalyst particles and the reactor operating conditions greatly influence the reactor performance and the product composition. Firstly, the present study investigated the effect of catalyst shape（sphere, cylinder and ring） on the MSR using a diffusion-reaction model on the particle scale. The effectiveness factors of shaped catalysts followed the sequence： cylinder sphere ring. Next, a one-dimensional mathematical model was developed by taking into account the mass, heat and momentum transfer on the reactor scale together with the diffusion-reaction equations on the catalyst scale, and used to describe an industrial MSR reactor. The effects of inlet temperature and pressure on the profiles of temperature and pressure inside the reactor, effectiveness factor, conversion of methane as well as concentration of various species were studied. Finally, the optimal inlet temperature and pressure for the industrial reactor were determined, being 773 K and 3 MPa, respectively.