Evaluation of Emissions of 2-Amino-2-Methyl-1-Propanol Degradation Products by adding Degradation Reactions to the Carbon Dioxide Capture Unit

Abstract

Degradation is a major problem which poses lots of emission risk during chemical absorption process with amine solvents. Degradation occurs through irreversible side reactions with CO₂ and other flue gas components, forming into products that cannot easily regenerate. The degradation products then react with amines to form thermally stable salts, which accumulate in the system over time. The problems associated with degradation include decreased plant equipment life, foaming, corrosion, high solution viscosity, and increased operating cost. Amines capture about 70 90% CO₂ from commercial power stations. These high removal rates have many environmental impacts due to their degradation products. Researchers have therefore shown interest in characterising and quantifying atmospheric emissions of amines and their degradation products. In this study, 2-Amino-2-Methyl-1-Propanol (AMP) degradation reactions were included into a largescale capture plant model to evaluate the influence of process variables, the emissions of AMP and its degradation products. Steadystate simulations were performed using Aspen Plus® V8.4 software to provide a full assessment of the degradation products and their impact on the capture process. This assessment is important because it identifies and quantifies all pollutants emitted from the process plant. The results of the simulation indicate that AMP emissions are 3.04E+03mg/Nm3 of CO₂ lean flue gas, while the quantity of AMP lost due to degradation was 37.88kg/s for the largescale capture plant. The results further showed that among the gases emitted, ammonia was highest, while acetone was the highest gas formed. In this study, 2-amino-2-methyl-1-propanol (AMP) degradation reactions were included into a largescale carbon dioxide (CO₂) capture plant model to evaluate the influence of process variables, AMP emissions and its degradation products. Steadystate simulations were performed using Aspen Plus® V8.4 software to provide a full assessment of the degradation products and their impact on the largescale AMP capture process. The results of the equilibrium model developed in this study revealed that AMP emissions are 3.04E+03mg/Nm³ of CO₂ lean flue gas, while the quantity of AMP lost due to degradation was 37.88kg/s for the largescale capture plant. More importantly, the emissions obtained from the PWOD and PWD are 7.80E+03 mg/Nm³ and 9.82E+03 mg/Nm³ of CO₂ respectively.

Keywords: oxidative degradation, 2amino2methyl1 propanol, emissions, modelling