Fundamental reaction kinetics of high-pressure reductive amination of polyalkylene glycol.

[Display omitted] • NH 3 amount affects PEA reaction even if rate-limiting is known to be dehydrogenation. • NH 3 dissolution into liquid PAG was essential for increasing the amine yield to around 99%. • A Langmuir-Hinshelwood kinetic model was established at a high pressure around 150 bar. • Absence of NH 3 caused the formation of secondary amine from primary amines with H 2. This study investigates reaction kinetics of high-pressure amination of polyalkylene glycol (PAG) to polyetheramine (PEA). The reductive amination of PAG was carried out depending on the NH 3 amount, reaction temperature, reaction pressure, and H 2 O content in a batch reactor to understand the effect of these factors on activity and selectivity toward the primary amine. Contrary to the fact that the amination step is a zero-order reaction and dehydrogenation of alcohol to ketone is the rate-limiting step in the reductive amination of alcohol, the amount of NH 3 significantly affected the reaction rate. The increased amount of NH 3 enhanced the activity and selectivity for PEA, in contrast with the results reported in prior studies. A Langmuir-Hinshelwood kinetic model was established to reflect the effect of the NH 3 amount, and kinetic parameters such as the rate constant and activation energy were obtained at a high pressure around 150 bar. It was also found that the absence of NH 3 caused the reverse reaction of PEA to the secondary amine in the presence of H 2. The fundamental kinetic analysis provides a competitive synthesis route for improving the activity and selectivity toward the primary amine. [ABSTRACT FROM AUTHOR]