改良天然气吹硫工艺在硫磺回收装置的应用

Application of improved process of blowing off residual sulfur with natural gas on sulfur recovery unit

关键词:  硫磺回收  达标排放  天然气  吹硫  停工

Key words:  sulfur recovery  discharge to reach standard  natural gas  blow off residual sulfur  shutdown

摘要:

介绍了改良天然气吹硫工艺原理及其在硫磺回收装置上的应用情况。该工艺从以下两个方面进行改良:①使用天然气和氮气的混合气体进行停工,通过制硫炉掺入氮气增加停工期间载硫、载热气量,缩短停工时间；②通过计算确定停工过程配风量,避免设备、催化剂局部超温,应用改良天然气吹硫停工工艺,中国石化北京燕山分公司60 kt/a硫磺回收装置在未设置烟气后碱洗塔的情况下,成功地将停工吹硫、钝化期间尾气焚烧炉排放的烟气中SO₂质量浓度控制在100 mg/m³以内,实现了达标排放。该改良工艺具有显著的社会效益,可以进一步推广应用。 

Abstract:

This paper introduces the principle of improved shutdown process by using natural gas and its application on sulfur recovery unit. The process was improved from following aspects:(1) A mixture of natural gas and nitrogen for shutdown was used. The addition of nitrogen into the Claus furnace increased the amount of sulfur and heat-carrying gas during the shutdown period and shortened the downtime. (2) The air distribution during the shutdown process was determined through calculation to avoid over-temperature of the equipment and catalysts. The industrial application of Sinopec Beijing Yanshan Branch 60 kt/a sulfur recovery unit showed that the flue gas SO₂ mass concentration emitted from the tail gas furnace during shutdown and blowing could be controlled within 100 mg/m³ without setting caustic wash tower, which reached the discharge standard. The improved process has significant social benefits which can be further promoted and applied.