| 摘要 |
<p>Continuous preparation of alpha-hydroxycarboxylic ester comprises reacting reactants of alpha-hydroxycarbamide with an alcohol in the presence of a catalyst to obtain a product mixture; feeding the reactant stream comprising reactant, an alpha-hydroxycarboxamide, an alcohol and a catalyst into a pressure reactor; and depleting the product mixture in alcohol and ammonia, where the ammonia is distilled off at a pressure, which is constantly kept greater than 1 bar without aid of additional stripping media. Continuous preparation of alpha-hydroxycarboxylic ester comprises reacting reactants of alpha-hydroxycarbamide with an alcohol in the presence of a catalyst to obtain a product mixture comprising alpha-hydroxycarboxylic ester, ammonia, unconverted alpha-hydroxycarboxamide, alcohol and catalyst; feeding the reactant stream comprising reactant, an alpha-hydroxycarboxamide, an alcohol and a catalyst into a pressure reactor, where the reactant stream are reacted with one another in the pressure reactor at 1-100 bar; and depleting the product mixture in alcohol and ammonia, where the ammonia is distilled off at a pressure, which is constantly kept greater than 1 bar without aid of additional stripping media.</p> |
