控制凝液产品中CO_(2)含量的乙烷回收流程改进

Improvement of ethane recovery process for controlling CO_(2) content in condensate products

研究了RSV流程CO_(2)冻堵机理和控制手段,RSV流程可以通过控制合理的工艺参数和设置预分离器的方式控制冻堵;分析了RSV流程和脱甲烷塔中CO_(2)的分布规律,结果表明,控制凝液产品中CO_(2)含量需要将脱甲烷塔下部的CO_(2)气化并使得之进入上部;在RSV流程基础上,改进双塔RSVC流程,双塔设置可以实现脱甲烷塔顶气相对吸收塔底部液相中CO_(2)进行汽提,提高吸收塔中的CO_(2)浓度,设置预分离器可以在吸收塔气相中CO_(2)含量升高后控制CO_(2)冻堵。RSV和RSVC流程对比结果表明,RSVC流程在几乎不影响乙烷收率情况下,使凝液产品中的CO_(2)含量能降低约2.4%。

The mechanism and control methods of CO_(2) freezing blockage in recycle split vapor(RSV)process are studied.As for RSV process,CO_(2) freezing blockage can be controlled by controlling reasonable process parameters and setting a pre-separator.Distribution rules of CO_(2) in RSV process and demethanizer are analyzed.Results show that CO_(2) in the lower part of the demethanizer must be gasified and enter the upper part of that so as to control CO_(2) content in the condensate products.Based on the above results and RSV process,RSVC,a modified RSV process with double towers is proposed,in which CO_(2) in the liquid phase at the bottom of the absorption tower is stripped to concentrate CO_(2).A preseparator is set to control CO_(2) freezing blockage once CO_(2) content in the gas phase of the absorption tower rises.Comparison between RSV and RSVC processes show that RSVC process can reduce CO_(2) content in the condensate products by 2.4%while it brings about little impact on the yield of ethane.