低负荷下双塔分子筛脱水工艺对产品天然气中H2S含量的影响

Effect of two-tower molecular sieve dehydration technology on natural gas purity under low load

中国石油西南油气田公司川西北气矿天然气净化厂脱水装置采用分子筛吸附脱水双塔工艺,一塔吸附,一塔再生,二者切换使用。在低负荷运行状态下,分子筛塔进行再生时,其产品气中H2S含量出现周期性波动情况,存在超标的潜在风险。经过研究与分析制定了优化调整方案,通过延长吸附再生切换周期、减少再生时间、降低再生温度等操作后,分子筛脱水装置再生时产品气中H2S质量浓度降至10 mg/m^3以下,并趋于平稳,较好地解决了这一生产异常问题。

The molecular sieve adsorption dehydration two-tower process is adopted on dehydration unit of Natural Gas Purification Plant,Northwest Sichuan Gas District,PetroChina Southwest Oil&Gasfield Company,including one tower adsorption and one tower regeneration,and the two towers are switched to use.Under low load operation,the H2S content in the product gas of the molecular sieve tower fluctuates periodically during regeneration,and there is a potential risk of exceeding the standard.After research and analysis,the optimized adjustment scheme was made.By prolonging the switching period of adsorption regeneration,reducing regeneration time and regeneration temperature,the H2S mass concentration in product gas of the molecular sieve dehydration unit during regeneration was reduced to less than 10 mg/m^3,and tended to be stable.The abnormal production problem was solved well.