Stressing the AMP/PZ-Based Solvent CESAR1─Pilot Plant Testing on the Effect of O2, NO2, and Regeneration Temperature on Solvent Degradation

Abstract

Degradation of amine-based CO₂ capture solvents causes not only higher solvent consumption but also more effort for controlling the emissions of volatile degradation products and for the removal of degradation products that are accumulating in the solvent. Guiding principles to minimize degradation processes generally are targeting at the reduction of oxidative and thermal stress for the solvent during the operation of the capture plant. For example, it is recommended to reduce the contact of potentially aggressive compounds in the flue gas, like O₂ and NO₂, with the amines as much as possible by their removal from the flue gas or the solvent. Additionally, the maximum temperature of the CO₂-loaded solvent in the reboiler and desorber sump and the time of exposure should be minimized. The results of testing campaigns with the CESAR1 solvent at the pilot plant at Niederaussem show that the effects of elevated O₂ and NO₂ contents in the flue gas (increase from 5 to 16 vol % O₂ and from <0.1 to >53 mg/m³ NO₂) and of an elevated solvent regeneration temperature (increase from 120 to 130 °C) are small.