(542c) A Techno-Economic Evaluation of Various Stripper Configurations in Amine Absorption Technology for Post-Combustion Carbon Capture

As a part of this work, we are comparing the techno-economic performance of the amine absorption process under a variety of stripper operating conditions – ranging from vacuum strippers operating at 30 kPa to high pressure strippers operating at 300 kPa. We are modeling the amine absorption process using the process simulation software ProMax® with TSWEET®. The equipment sizing and capacity data thus generated are the feed parameters for Aspen Process Economic Analyzer which provides the cost estimates for the process equipment.

In our previous studies, we have reported the comparisons of energy consumption and absorber-stripper column sizing for monoethanolamine (MEA), diethanolamine (DEA) and diglycolamine (DGA) at varying concentrations and stripper operating conditions [1]. Of the three amines compared, we’ve identified 40 wt% DEA and 60 wt% DGA as the more suitable amines for carbon capture application than MEA. We have also shown that an increase in the stripper operating pressure results in a reduced reboiler energy duty and a smaller stripper column [2]. Use of very low pressure steam - waste heat, results in a reduced ‘parasitic energy duty’ at the power plant but results in larger stripper columns and increased load on the compression train.

It can be seen that there are two contrasting factors involved in deciding the optimal operational configuration – potential energy savings by reduction of parasitic duty and an increase in the capital expenditure with increasing the equipment sizes. Thus, in spite of the detailed technical analysis conducted previously; it hasn’t been possible to predict the optimal configuration amongst those compared. The aim of the techno-economic analysis undertaken as a part of this study is to predict with some clarity the better performing absorbent and the corresponding system configuration.

References

1. S. S. Warudkar, K. R. Cox, M. S. Wong and G. J. Hirasaki, “Comparison of alkanolamines for post-combustion carbon capture from a pulverized coal fired power plant”, AIChE Fall Meeting, Minneapolis, MN (2011).

2. S. S. Warudkar, K. R. Cox, M. S. Wong and G. J. Hirasaki, “Amine absorption with vacuum stripping for post-combustion carbon capture”, AIChE Spring Meeting, Houston, TX (2012).