氨厂二段炉操作的优化

Operation optimization of the secondary reformer of an ammonia plant

采用过程模拟的方法，对氨厂二段炉的优化操作进行了研究。模拟结果表明，为了得到最高氢产量，二段炉适宜的空气添加量是随进口条件不同而不同的，但二段炉出口的甲烷含量却几乎都在０．４％～０．６％范围，表明二段炉出口甲烷含量不宜小于０．４％。提高工艺空气预热温度可以提高氢产量，但其适宜空气添加量较少，不能满足合成氨对氢氮比为３的要求，为此可以降低一段炉水碳比或降低一段炉出口温度。

Optimization of operating the secondary reformer in an ammonia plant is investigated by process simulation. The results show that in order to obtain maximum hydrogen production, an appropriate amount of air added to the secondary reformer depending on its inlet conditions, while all methane concentrations at the outlet of the reformer are almost in a range of 0 4%～0 6%,indicating that the outlet concentration of methane from the secondary reformer should be no less than 0 4%.Although hydrogen content can be increased by raising preheating temperature of process air,the appropriate amount of air added is too small to meet the requirement for V(H 2)/V(N 2)=3.An aptimal result of raising production and saving energy can,therefore,be achieved by decreasing H 2O/C ratio or outlet temperature of the primary reformer and increasing appropiate amount of air added to the secondary reformet.