微反应器甲烷水蒸气重整毫秒级制氢过程的CFD模拟的研究.pdfVIP

微反应器甲烷水蒸气重整毫秒级制氢过程的CFD 模拟研究* 程音弘，翟绪丽，程易 （清华大学反应工程实验室，北京 100084） 摘要：针对在微反应器中进行的耦合了水蒸气重整反应和甲烷燃烧反应的毫秒级制氢过程进行了基于基元 反应动力学的CFD 模拟研究。对水蒸气重整通道中使用的Rh 催化剂和Ni 催化剂的反应性能进行了对比， 研究了Ni 催化剂下壁面导热能力和反应通道大小对反应结果的影响，并通过引入带有催化剂层扩散的模型 对原有模型进行了改进。结果表明，Rh 催化剂的反应性能显著好于Ni 催化剂，通过提高Ni 催化剂负载量 和增加催化剂层厚度等手段可以使Ni 催化剂的反应性能接近于Rh 催化剂。壁面导热能力显著影响热点温 度的产生，在相同处理能力下，适当的孔道大小能够获得更高的甲烷转化率。带有催化剂层扩散的模型比 原有模型更能反应真实的反应过程。 关键词：制氢；微反应器；基元反应动力学；CFD ； CFD simulation with detailed chemistry of steam reforming of methane for hydrogen production in an integrated micro-reactor Cheng Yinhong ，Zhai Xuli ，Cheng Yi (Department of Chemical Engineering, Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology, Tsinghua University, Beijing 100084, PR China) Abstract ：The CFD simulation with detailed chemistry had been made to research the steam reforming of methane coupled with the combustion of methane for millisecond-time hydrogen production in an integrated micro-reactor. The performances of Rh and Ni catalyst in the reforming channel were compared and the influences of wall thermal conductivity and channel size to the final CH conversion were studied. Moreover, a new model considering the diffusion 4 during the catalyst layer was induced to modify the old model. The results show that the Rh catalyst performs much better than the Ni catalyst; however, we can achieve almost the same performance by increasing the catalyst loading and the thickness of catalyst layer. The appearance of hot spot in the solid wall is decided by the wall thermal conductivity. On the other hand, the channel size during a specific range can lead to a higher CH