| The carbon dioxide (CO{dollar}sb2{dollar}) absorption process, using aqueous alkanolamine solutions, has been extensively used for many decades. With its high absorption capacity, 2-amino-2-methyl-1-propanol (AMP) has been recently proposed as a commercially attractive solvent in place of conventional alkanolamines, especially monoethanolamine (MEA). The corrosion aspect is considered because corrosion has long presented the most severe operating difficulty in conventional alkanolamine plants.; Static weight loss tests were performed to investigate the corrosivity of plain carbon steel in AMP solutions saturated with either pure CO{dollar}sb2,{dollar} or a mixture of CO{dollar}sb2{dollar} and air under boiling conditions. The effects of alkanolamine concentration and oxygen contamination were also studied. The corrosion data of the AMP system were compared with those of a conventional alkanolamine, namely a MEA system, simultaneously tested under the same conditions. The results indicated that the AMP system was generally less corrosive to carbon steel than the MEA system. For the alkanolamine concentration effect, the corrosion rates in the AMP system tended to stabilize when the concentration reached 5 kmol/m{dollar}sp3{dollar} while those in the MEA system were directly proportional to the alkanolamine concentrations. Furthermore, it was found that 10% oxygen in the feed gas would increase the corrositivity in both MEA and AMP systems by approximately 1.5 to 3 times.; Corrosion inhibitor testing was conducted in order to check potential corrosion inhibitors. Three chemicals, sodium metavanadate (NaVO{dollar}sb3{dollar}), sodium sulfite (Na{dollar}sb2{dollar}SO{dollar}sb3{dollar}), and 2-aminothiophenol (ATP) were tested in the 5 kmol/m{dollar}sp3{dollar} AMP solutions saturated with a mixture of CO{dollar}sb2{dollar} and air under boiling conditions. The NaVO{dollar}sb3{dollar} and Na{dollar}sb2{dollar}SO{dollar}sb3{dollar} were effective, with more than 90% protection, while the ATP failed the tests because its corrosion data were irreproducible. (Abstract shortened by UMI.)... |
