Degradation of MDEA in aqueous solution in the thermally activated persulfate system

Abstract

The feasibility of methyldiethanolamine (MDEA) degradation in thermally activated PS system was evaluated. Effects of the PS concentration, pH, activation temperature and reaction time on MDEA degradation were investigated. Simultaneity, the thermodynamic analysis and degradation process were also performed. Several findings were made in this study including the following: the degradation rates of MDEA in thermally activated PS systems were higher than other systems. MDEA could be readily degraded at 40°C with a PS concentration of 25.2 mM, the process of MDEA degradation was accelerated by higher PS dose and reaction temperature, and MDEA degradation and PS consumption followed the pseudo-first-order kinetic model. The thermodynamic analysis showed that the activation process followed an endothermic path of the positive value of [Formula: see text] and spontaneous with the negative value of [Formula: see text], high temperature was favorable to the degradation of MDEA with the apparent activation energy of 87.11 KJ/mol. Combined FT-IR with GC-MS analysis techniques, MDEA could be oxidative degraded after the C-N bond broken to small molecules of organic acids, alcohols or nitro compounds until oxidized to CO and HO. In conclusion, the thermally activated PS process is a promising option for degrading MDEA effluent liquor.

Experimental Study on Simultaneous Absorption and Desorption of CO2, SO2, and NOx Using Aqueous N-Methyldiethanolamine and Dimethyl Sulfoxide Solutions

“…The SO 4 2– and NO 3 – ions showed little negative influence on the further absorption of CO 2 /SO 2 /NO x (see section for details). Some research indicated that SO 4 2– promoted the degradation of MDEA; thus, the MDEA+DMSO solution requires the replacement or the supplement of fresh solution if the solution cannot meet the absorption requirements after many absorption–desorption cycles.…”

“…The former is easily desorbed, while the latter is much harder. Thus, the addition of DMSO in MDEA aqueous solution will reduce the generation of heat-stability salts, which play a dominant role in the process of MDEA degeneration …”

“…Thus, the addition of DMSO in MDEA aqueous solution will reduce the generation of heatstability salts, which play a dominant role in the process of MDEA degeneration. 39 In this paper, an aqueous MDEA+DMSO solution was used as the absorption solvent for the simultaneous removal and desorption of CO 2 , SO 2 , and NO x . The absorption and desorption performances of the aqueous MDEA+DMSO solution were explored in a static absorption−desorption semibatch system.…”

Study on the Jet-Cyclone Coupled Separation Performance of Solvent Naphtha Containing MDEA

“…This solvent naphtha is used to process gasoline. As gasoline is burned, the exhaust emissions may contain harmful substances produced by the decomposition of MDEA, such as nitrate, which can cause nausea, breathing difficulties, and nervous system and respiratory diseases. − So removing MDEA entrained in solvent naphtha is not only conducive to protecting public health and environmental safety but also conducive to improving the quality and competitiveness of solvent naphtha products.…”

Volumetric and Viscometric Properties for Binary and Ternary Solutions of Diethylenetriamine, N,N-Diethylethanolamine, and Water

“…Primary amines (ethanolamine, MEA) and secondary amines (diethanolamine, DEA), as a typical chemical solvent, have the advantages of fast absorption rate and high product purity but have some drawbacks, for example, low CO 2 absorption capacity and high regeneration energy consumption. On the contrary, tertiary amines ( N -methyldiethanolamine, MDEA) and sterically hindered amines (2-amino-2-methyl-1-propanol, AMP) have low regeneration energy consumption and large absorption capacity in the CO 2 capture process, while their absorption rate is relatively slow. Enamine (diethylenetriamine, DETA) exhibits a fast CO 2 absorption rate and high absorption capacity; however, its high viscosity, low absorption efficiency, and high price limited its commercialization.…”