Thermal degradation of monoethanolamine and its effect on CO2 capture capacity

Abstract

Amine scrubbing is a proven technology in the oil and gas industries. Its use in coal fired power plants is not fully understood and the likelihood of solvent degradation is high. Decreased absorption efficiency, undesirable by-products and the environmental impact of their disposal are the main consequences. In the present study, samples of monoethanolamine were thermally degraded, at 160•C for between 2 and 8 weeks, and their CO2 removal capacity deterioration was determined. The findings show that thermal degradation at 160•C for 8 weeks reduced monoethanolamine concentration by 95%, but the remaining solvent still retained 22% of its capacity to remove CO2, probably due to the capacity of some of the degradation products to remove CO2. Therefore, the requirement for monoethanolamine make-up in operational amine scrubbing systems may not be quite as serious as initially believed. A 20% higher MEA loss was determined in the samples with 0.37 initial CO2 loading (mol CO2/mol MEA). 2-Oxazolidone, N-(2-hydroxyethyl)-ethylenediamine and 1-(2-hydroxyethyl)-2-imidazolidinone were identified as the major monoethanolamine degradation products, the latter being indicated as the most stable product with concentrations of up to 17% (v/v). Corrosion (1.95 mm/year) of the stainless steel (type 316) equipment, used during the experiments, was also observed.

Degradation of amine-based solvents in CO2capture process by chemical absorption

“…Then, the multiple vessels were placed in convection ovens and heated at the desired temperature and then withdrawn at regular intervals to be analyzed. The number of vessels used depended on the regular intervals assumed and the total time required for each experiment . Thermal degradation experiments in the presence of O 2 have been carried out using an ISDA .…”

ATR-FTIR Model Development and Verification for Qualitative and Quantitative Analysis in MDEA–H2O–MEG/TEG–CO2 Blends

“…Amine-based acid gas removal processes consist of two steps, absorption, and stripping, where temperature swing is used to regenerate acid gas in stripping [9]. Thermal degradation takes place at the stripping stage due to high temperatures [44,45] and can cause various problems such as an increase in solvent viscosity, foaming, fouling, corrosion and a reduction in the absorption capacity of the solvent [46][47][48][49][50][51]. In the case of using an amine solution in glycol, simultaneous acid gas and water removal are possible [11][12][13][14], and at the stripping stage, the amine-glycol solutions will also contain acid gas and water.…”

Gas–liquid equilibrium data for mixture gas of carbon dioxide + nitrogen in 1,2-ethanediamine + triethylene glycol aqueous solution

“…[24] The equipment was initially designed to determine GLE data based on the static-analytic method. In this work, CO 2 /N 2 mixtures from the gas cylinder (9) were poured into the apparatus through switching the regulating valves K1 and K2 (6) and recycled through jacketed vessel (1), cold trap (2) and gas circulatory pump (4) for whole recycling process. Liquid was controlled at experimental temperature using the thermostatic bath (3) and registered on a standard thermometer (7) at different points, and the temperatures did not vary more than 0.02 K for about 30 min.…”

“…[2,3] Presently, many technologies have been developed for the separation and capture of CO 2 , including absorption, [4] adsorption, [5] membrane separation technique, [6] hydrate-based separation process [7] and disposal of CO 2 in deep ocean. [8] Among these technologies, the absorption technology using amine solutions, such as monoethanolamine, [9] diethanolamine, [10] triethanolamine, [11] N-methyldiethanolamine, [12] diglycolamine [13] and EDA, [14] is widely used to capture CO 2 and is considered as the most industrially developed technology for CO 2 absorption. However, the cost of the amine-based absorption processes is relatively high due to the volatilisation of amines, resulting in the consumption of large amounts of energy in the absorption and regeneration processes.…”