Construction and Operation of a non-Metallic Pilot CO2 Capture Rig

Abstract

This study describes the construction and operation of a non-metallic pilot CO2 capture rig, built in the LAUNCH CCUS project to analyse oxidative solvent degradation in a continuous CO2 capture process where metal concentrations in the solvent are constant. This can aid in creating better understanding of oxidative degradation of amine solvents, and can further help to evaluate the potential of building non-metallic CO2 capture systems. The equipment and material selection for the non-metallic rig is discussed. A first campaign is conducted using MEA as the capture solvent, where the iron concentration in the solvent is gradually increased over the course of several weeks. In the start of the campaign, the rig could be operated according to its design specifications. This was not possible anymore in the final part of the campaign, due to leakages occurring at the stripper, and water balance issues. Liquid phase analysis of the solvent during the campaign shows the concentration of MEA, concentration of metals and concentration of major oxidative degradation products. Results from the analysis in this campaign should be analysed with caution, since the operation of the rig was not stable in the latter part of the experiment. The results from the experimental campaign give a first indication of the usefulness of operating such a non-metallic CO2 capture rig to give further insights in oxidative degradation, while also giving insights where difficulties are in designing CO2 capture systems without metal equipment. For a potential future campaign, the rig should be redesigned to fix some of the problems encountered in this first campaign, and it is recommended that in a next campaign, the rig is operated for several months without adding any metals to the solvent.

Keywords: CO2 capture, non-metallic capture rig, oxidative solvent degradation, solvent stability