Methyldiethanolamine

A variety of substituted alkanolamines (Table 2) can also be made by reaction of oxide with the appropriate amine. Aminoethylethanolamine is made from the reaction of ethylenediamine [107-15-3J and ethylene oxide. Methyldiethanolamine is made from the reaction of ethylene oxide and methylamine [74-89-5J. Diethylethanolamine is made by the reaction of diethylamine [109-87-7] and ethylene oxide. 

DIPA) and methyldiethanolamine (MDEA) have also been employed. Earlier, Atwood et al. (J 5) proposed a thermodynamic model for the equilibria in I S+alkanol-amine+H20 systems. The central feature of this model is the use of mean ionic activity coefficient. The activity coefficients of all ionic species are assumed to be equal and to be a function only of ionic strengths. Klyamer and Kolesnikova ( 1j[) utilized this model for correlation of equilibria in C02+alkanol-amine+H O systems and Klyamer et al. (J 7) extended it to the H2S+C02+alkanolamine+H20 system. The model is restricted to low pressures as the fugacity coefficients are assumed unity and it has been found that the predictions are inaccurate in the four-component system since the activity coefficients are not equal when a number of different cations and anions are present. 

Al-Ghawas, H.A., Hagewiesche, D.P., Ruiz-lbanez, G., and Sandall, O.C. Physicochemical properties important for carbon dioxide absorption in aqueous methyldiethanolamine, /. Chem. Eng. Data, 34(4) 385-391, 1989. 

Davis, R.A. and Pogainis, B.J. Solubility of nitrous oxide in aqneons blends of TV-methyldiethanolamine and 2-amino-2-methyl-1-propanol, J. Chem. Eng. Data, 40(6) 1249-1251, 1995. 

Rinker, E.B., Ashour, S.S., and Sandall, O.C. Kinetics and modeling ofcarbon dioxide absorption into aqueous soluUons of//-methyldiethanolamine, Chem. Eng. Sci., 50(5) 755-768, 1995. 

Alkanolamines. Gas sweetening, ie, removal of hydrogen sulfide and carbon dioxide, using alkanolamines was patented in 1930. Several amine solvents are available as of the mid-1990s. The most widely used are monoethanolamine [141-43-5], diethanolamine [111-42-2], diglycolamine [929-06-6], and methyldiethanolamine [105-59-9]. Amine processes are generally applicable when hydrogen sulfide concentration in the feed gas is relatively low (eg,... 

Bis(2-chloroethyl)methylamine hydrochloride. N-methyldiethanolamine (59.58 g, 0.5 mole) is dissolved in 50 mL of chloroform and added dropwise with stirring to a solution of freshly distilled thionyl chloride (158.17 g, 1.33 mole) in 70 mL of chloroform. After the addition is complete, the solution is refluxed for 3 h and then left to stir overnight at room temperature. The solvent and the excess thionyl chloride are removed by rotary evaporation to yield an off-white solid. This product is recrystallized from acetone and... 

Figure 4 Molecular structure of n-methyldiethanolamine (MDEA) and piperazine (PZ).

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