Characteristics of CO2 Absorption and Degradation of Aqueous Alkanolamine Solutions in CO2 and CO2-O-2 System

Amine can undergo irreversible reactions by O-2 and high temperature in amine scrubbing process and these phenomena are called "degradation". Degradation causes not only a loss of valuable amine, but also operational problems such as foaming, corrosion and fouling. In this study, using various chemical absorbents(MEA; monoethanolamine, AMP; 2-amino-2-methyl-1-propanol, DAM; 1,8-diamino-p-menthane), we examined the following variable. i) loading ratio of CO2 at 50 degrees C and 120 degrees C, ii) concentration variation and initial degradation rate constant of absorbent in CO2 and CO2/O-2 system, and iii) effect of degradation by O-2. The CO2 loading of 20 wt% DAM was 400% and 270% higher than that of 20 wt% MEA and AMP at 50, respectively and was the largest the difference of CO2 loading between absorption (50 degrees C) and regeneration (120 degrees C) condition. The initial degradation rate constant of 20 wt% DAM was 2.254x10(-4) cycle(-1) which was slower than that of MEA (2.761x10(-4) cycle(-1)) and AMP (2.416x10(-4) cycle(-1)) in CO2 system. Also, it was increased 30% by O-2 that effects on the degradation by O-2 was less than 100% increased. these degradation reactions was able to identify by formation of new peak in GC and FT-IR spectrum analysis.