正交试验及响应面优化在乙烷回收中的对比

Comparison between orthogonal test and response surface optimization in ethane recovery

为解决部分干气再循环乙烷回收工艺进行富气乙烷回收时能耗高的问题,采用单因素分析法和灵敏度分析法优选出对乙烷回收率和总压缩功耗影响较大的4个工艺参数及其最优值范围。再采用正交试验法和响应面法进行参数优化,响应面法从方差分析、帕累托图分析和优化等方面得出最佳工艺参数脱甲烷塔压力为2 800 kPa、低温分离器温度为-47.54℃、外输干气回流比为14.8%、低温分离器气相分流比为14.02%、乙烷回收率和总压缩功耗分别为93.43%、7 694.05 kW,乙烷回收率和总压缩功耗均优于正交试验结果92.87%、7 784.05 kW。在参数较小情况下,考虑减少试验工作量推荐选用正交试验法。但通过响应面法建立的二次回归优化模型,不仅可以优化工艺参数,也可以量化参数间交互作用对乙烷回收率和总压缩功耗的影响,为现场工艺参数调整提供理论基础。

To address the issue of high energy consumption in the ethane recovery from rich gas using the Recycle Split Vapor(RSV) ethane process,four key process parameters affecting the recovery rate and the total compression power consumption are identified and their optimal value ranges are selected through single-factor and sensitivity analysis.Subsequently,parameter optimization was conducted using orthogonal test method and response surface methodology.The response surface methodology,through variance analysis,Pareto diagram analysis,and optimization,yielded the following optimal process parameters:demethanizer column pressure at 2 800 kPa,cryogenic separator temperature at-47.54 ℃,dry gas reflux ratio at 14.8%,and cryogenic separator gas-phase split ratio at 14.02%.The ethane recovery rate and total compression power consumption achieved were 93.43% and 7 694.05 kW respectively,outperforming the previous values of 92.87% and 7 784.05 kW.When dealing with fewer parameters,the orthogonal test method is recommended to reduce the test workload.However,the quadratic regression optimization model established by the response surface methodology not only optimizes the process parameters,but also quantifies the interaction effects of parameters on the ethane recovery rate and the total compression power consumption,providing a theoretical basis for the process parameters adjustment on site.