天然气深度脱碳分流解吸工艺研究

Study on deep decarbonization and split desorption process of natural gas

关键词:  天然气  深度脱碳  分流解吸  节能

Key words:  natural gas  deep decarbonization  split desorption  energy saving

摘要:

目前,常规天然气深度脱碳工艺能耗大,具体表现在再生塔温度高、重沸器热负荷过大、工艺流程换热简单、换热网络集成度小、热量损失多等方面。研究了一种分流解吸工艺,该工艺中物料分两股进入再生塔,回收再生塔塔顶气相热量,减少塔顶冷却器的冷却水用量,从而减少重沸器热负荷,达到一定的节能效果。结果 表明,分流解吸工艺比常规工艺节能,当原料气中CO₂摩尔分数为3.63%时,最佳分流比为0.3,此时净化效果最好；当原料气中CO₂摩尔分数为20%时,最佳分流比为0.4,此时净化效果最好。第2股选择进料位置时,建议选取中部偏上两块塔板(第8块)作为最佳进料位置。 

Abstract:

At present, the energy consumption of conventional natural gas deep decarbonization process is high, which are shown as follows:high temperature of the regenerator, large heat load of reboiler, simple heat exchange flow, small heat exchange network integration, and the high heat loss. A split desorption process was studied. In this process, two materials entered the regenerator to recover the heat of the top gas in the regenerator, and reduce the cooling water flow of overhead cooler, thereby reducing the heat load of reboiler and achieving a certain energy saving effect. The results showed that the split desorption process could save more energy than the conventional process. When the CO₂ molar fraction in the feed gas was 3.63%, the optimum split ratio was 0.3, and then the purification effect was best. When the CO₂ molar fraction in the feed gas was 20%, the optimum split ratio was 0.4, and then the purification effect was best. When the second stock was selected for the feed position, it was recommended that the eighth plate should be selected as the optimum feed position.