Ethanolamine processes selection

After cooling, the gas enters the amine absorber where essentially all of the hydrogen sulfide is removed, but only a portion of the carbon dioxide is coab.sorbed. The rich amine solution is stripped of acid gas in the regenerator by application of indirect heat supplied by a steam heated rehoiler, and the acid gas is returned to the Claus unit. This portion of the process is quite similar to the conventional selective ethanolamine processes discussed in Chapter 2. 

Also the impact of various reaction parameters on enzymatic synthesis of amide surfactants from ethanolamine and diethanolamine has been studied, although the possibilities of acyl migration are not investigated. However, it was found that the selectivity of the reaction depended on the solubility of the product in the solvent used, and that the choice of solvent was critical to obtain an efficient process [17]. 

Gallic acid functions as an effective sihcon complexing agent in aqueous ethanolamine solutions. In its absence the etch rate is zero. Etch rate increases with water content. The additions of pyrazines, pyridazines, and triazoles show various catalytic effects on the etching process. The catalysts that lead to faster oxidation result in faster etch rates, and the difference among the catalysts is due to a steric effect. Oxidative catalysts tend to influence the etching selectivity of the major crystal... 

In addition to the equipment properties and selected operating conditions, the process performance depends to a large extent on the state of the active solvent component(s). Commonly nsed solvents include physical solvents like methanol (Rectisol) and the dimethyl ethers of polyethylene glycol (Selexol), chemical solvents like aqneous solutions of carbonates such as K2CO3 and Na2C03, of amino acid salts such as mixtures of potassium hydroxide and alanine or tanrine, and especially of alkanolamines such as mono-ethanolamine (MEA), di-ethanolamine (DEA), (activate) methyl-di-ethanolamine (MDEA), di-isopropanolamine (DIPA), di-glycolamine (DGA), 2-amino-2-methyl-l-propanol (AMP), and piperazine (PZ) (1). 

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