On the effects of surface waviness upon catalytic steam reforming of methane in micro-structured reactors - a computational study
On the effects of surface waviness upon catalytic steam reforming of methane in micro-structured reactors - a computational study
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DOI：
10.1016/j.ijhydene.2023.06.086
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发表时间：
2023-06
影响因子：
7.2
通讯作者：
Mohsen Esfandiary;Seifolah Saedodin;Nader Karimi
中科院分区：
文献类型：
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作者：
Mohsen Esfandiary;Seifolah Saedodin;Nader Karimi
用数值方法研究了以镍为催化剂的微结构催化反应器中波浪通道对蒸汽甲烷重整的影响。建立了具有非均相化学性质的层流三维反应流模型，并将其应用于具有不同内壁波型的微结构反应器。在反应器壁面上引入表面波可以显著改变h24和CH4的生成和消耗。这被证明是由于对流质量和热传递的大波动，由表面波纹引起的。特别是，浓度边界层和热边界层的分离和再附着以及随后Sherwood数和Nusselt数的变化对反应器壁面上的催化过程有显著影响。在舍伍德数和努塞尔数最大的地方，观察到催化过程的主要局部强化。同样，在舍伍德（和努塞尔）数最小的地方，催化过程变得非常低效。进一步的分析表明，用催化剂对波状壁进行战略性的离散涂覆可以显著地提高微观结构的性能。例如，与完全涂覆的等量直线通道相比，仅涂覆25%的波状壁表面积，每涂覆表面积的ch4转化率和选择性分别提高了459%和308%。这意味着有可能开发出高效率和具有成本效益的催化微反应器，用于从甲烷中生产氢。
The effects of wavy channels upon steam methane reforming in catalytic micro-structured reactors, using Nickle as the catalyst, are investigated numerically. Laminar, three-dimensional models of reacting flows, with heterogeneous chemistry, are developed and applied to micro-structured reactors with different wave patterns on their internal walls. It is observed that introduction of surface waves on the walls of reactor, can significantly alter production and consumption of H2and CH4. This is shown to be due to large fluctuations in convective mass and heat transfer, induced by the surface waviness. In particular, it is shown that separation and reattachment of concentration and thermal boundary layers and the subsequent modifications in Sherwood and Nusselt number can significantly affect the catalytic processes over the walls of reactor. A major local intensification of catalytic processes is observed where Sherwood and Nusselt number are maximised. Similarly, the catalytic process becomes highly inefficient in places with minimal Sherwood (and Nusselt) number. The analyses further reveal that a strategic discrete coating of wavy walls with the catalyst can substantially improve the performance of microstructure. For example, by coating only 25% of the surface area of wavy walls, CH4conversion rate and selectivity per coated surface area increase by 459% and 308% compared to those of an equivalent fully coated straight channel. This implies the possibility of developing highly efficient and cost-effective catalytic micro-reactors for production of hydrogen from methane.