驰放气回收在炼厂中的实践

Practice of Purge Gas Recycling in Refinery

国内炼厂驰放气往往因为热值较低,不适合做燃料气而直接进入火炬系统排放。若能将驰放气加以回收利用,则可减少造成资源浪费和环境污染。针对炼厂驰放气回收难和甲醇装置原料配比不合理的问题进行分析,通过对驰放气回收工艺方案进行改进,并采用"低压收集,分步增压"工艺,既能满足炼厂驰放气回收的要求,又能大幅降低设备投资。回收的驰放气作为甲醇装置的原料,可使原料气达到合适的氢碳比,既减少了天然气耗量,增加甲醇产量,又减少了CO2的排放,节能减排效果明显。

Due to low calorific value,released gas produced from domestic refineries is not suitable for fuel gas and led directly into flare system and vented to air after burning.If such released gas is recycled,it can be avoided to result in resource waste and environmental pollution.Conducted is analysis on such issues as difficult recovery of released gas from refinery and unreasonable feed gases ratio of methanol unit,improved is the recovery process of released gas and applied is the new process 'Low Pressure Gathering and Gradual Pressurization' so as to meet requirements of released gas recovery and substantial decrease of equipment investment.As one of feed gases of methanol unit,recovered released gas can make feed gases reach suitable hydrogen carbon ratio,accordingly,consumption of natural gas can be decreased,methanol output can be increased and CO_2 emissions can be decreased obviously,which has obvious effect in energy conservation and emissions reduction.