title: Nitrosamine formation in amine scrubbing at desorber temperatures.
abstract: Amine scrubbing is a thermodynamically efficient and industrially proven method for carbon capture, but amine solvents can nitrosate in the desorber, forming potentially carcinogenic nitrosamines. The kinetics of reactions involving nitrite and monoethanolamine (MEA), diethanolamine (DEA), methylethanolamine (MMEA), and methyldiethanolamine (MDEA) were determined under desorber conditions. The nitrosations of MEA, DEA, and MMEA are first order in nitrite, carbamate species, and hydronium ion. Nitrosation of MDEA, a tertiary amine, is not catalyzed by the addition of CO2 since it cannot form a stable carbamate. Concentrated and CO2 loaded MEA was blended with low concentrations of N-(2-hydroxyethyl) glycine (HeGly), hydroxyethyl-ethylenediamine (HEEDA), and DEA, secondary amines common in MEA degradation. Nitrosamine yield was proportional to the concentration of secondary amine and was a function of CO2 loading and temperature. Blends of tertiary amines with piperazine (PZ) showed n-nitrosopiperazine (MNPZ) yields close to unity, validating the slow nitrosation rates hypothesized for tertiary amines. These results provide a useful tool for estimating nitrosamine accumulation over a range of amine solvents.
authors: The University of Texas at Austin , McKetta Department of Chemical Engineering, 200 E Dean Keeton Street Stop C0400, Austin, Texas 78712-1589, United States.
authors: Nathan A
authors: NA
authors: Fine
authors: Mark J
authors: MJ
authors: Goldman
authors: Gary T
authors: GT
authors: Rochelle
mesh_terms: D000588:Amines / Q000737:chemistry*; D002219:Carbamates; D002244:Carbon; D019856:Ethanolamine; D004983:Ethanolamines; D005029:Ethylenediamines; D007700:Kinetics; D009573:Nitrites; D009602:Nitrosamines / Q000138:chemical synthesis*; D012997:Solvents; D013696:Temperature; D013816:Thermodynamics
chemical_list: D000588:Amines; D002219:Carbamates; D004983:Ethanolamines; D005029:Ethylenediamines; D009573:Nitrites; D009602:Nitrosamines; D012997:Solvents; C008430:N-methyldiethanolamine; D019856:Ethanolamine; C031234:ethylenediamine; D002244:Carbon; C020283:diethanolamine