甲烷催化部分氧化制合成气反应器的改进

Modification of Reactor for Catalytic Partial Oxidation of Methane to Synthesis Gas

在带空气分布器的固定床反应器中,以空气为氧源,采用NiO-La2O3/MgAl2O4-α-Al2O3催化剂,进行了甲烷催化部分氧化制合成气的研究。考察了空气流量分配比(D)对催化性能、催化剂床层轴向温度分布、催化剂床层轴向原料组成和产物分布的影响。实验结果表明,D不影响催化剂床层出口处的气体组成;当D为80%时,沿催化剂床层轴向n(O2):n(甲烷)可保持在0.10～0.22,催化剂床层入口处的温升明显下降,整个催化剂床层轴向温度分布均匀,表明采用空气分布器有利于提高甲烷部分氧化反应的选择性,抑制了甲烷的完全氧化。

Catalytic partial oxidation of methane by oxygen （air as oxygen source） to synthesis gas was investigated on NiO-La2O3/MgAl2O4-α-Al2O3 catalyst in a fixed-bed reactor with an air distributor. By using the air distributor, air can meet methane only on the active surface of the catalyst, so their gas-phase pre-mixing can be avoided. By using the air distributor, O2/CH4 mole ratio can be kept lower and the composition is beyond explosive limit to improve safety of the system. Effects of distribution ratio of air （expressed as D ） on catalytic performance, axial temperature distribution and axial species distribution along the catalyst bed were investigated. The results indicated that composition of products is determined by catalyst bed outlet temperature despite the changing of D. When D is 80%, low n （ O2 ） ： n （ CH4 ） （0. 10 -0. 22） is kept along the axial catalyst bed, the hot-spot forming near the entrance of catalyst bed is reduced, and an even temperature distribution along the whole axial catalyst bed was obtained, which ascribes to advantage of methane partial oxidation over its complete oxidation.