一段蒸汽转化炉出口甲烷含量偏高原因分析

Cause analysis of high methane content at the outlet of primary steam reformer

甲醇联合车间甲烷转化装置主要将原料油田气(主要成分为天然气)经过一段蒸汽转化反应后生成含有氢气、一氧化碳、二氧化碳的转化气。在生产操作中温度、水碳比、压力、催化剂会直接影响甲烷转化反应中甲烷的转化率。由于不同的操作方法导致不同的工况以及催化剂的不同状态,使蒸汽转化率发生变化,致使转化炉出口甲烷含量发生变化。转化气中的甲烷含量偏高时,表明甲烷转化率下降,导致送至下一工段合成系统的有效气量降低,最终将导致甲醇产量降低。本文针对甲烷转化装置在正常运行时,对转化炉出口转化气中甲烷含量偏高的原因进行分析,并提出解决措施。

Conversion gas containing hydrogen,carbon monoxide and carbon dioxide are generated from feed oil field gas(mainly composed of natural gas)after a primary steam conversion reaction in methane conversion unit of methanol combined workshop.During production operation,temperature,water carbon ratio,pressure and catalyst will directly affect the conversion rate of methane in the methane conversion reaction.Different operation methods lead to different working conditions and different catalyst states,which change the steam conversion rate and the methane content at the outlet of the reformer.When the methane content in the conversion gas is too high,it indicates that the methane conversion rate decreases,leading to the reduction of the effective gas volume sent to the synthesis system in the next section,which will eventually lead to the reduction of methanol output.In this paper,the reasons for the high methane content in the conversion gas at the outlet of the reformer during normal operation of methane conversion unit are analyzed and solutions are proposed.