Process for making ethanolamines

摘要

A process for the preparation of ethanolamines comprising reacting a water-ammonia solution with ethylene oxide to form an effluent reaction mixture comprising unreacted ammonia, water and ethanolamines. This effluent reaction mixture is then subjected to a succession of steps to, inter alia, separate the ethanolamines.

主权项

1. A process for the preparation of ethanolamines comprising the steps of:
(a) mixing a water-ammonia solution comprising from about 45% to about 60% ammonia and about 40% to about 55% water with ethylene oxide to form a reactor inlet composition; (b) charging the reactor inlet composition to one or more amine reactors; (c) reacting the ammonia with the ethylene oxide in the one or more amine reactors to form an effluent reaction mixture comprising unreacted ammonia, water and ethanolamines; (d) separating, in a first ammonia stripping column, the effluent reaction mixture into a rich ammonia-water mixture vapor overhead and a product solution bottoms liquid, the water-ammonia mixture vapor overhead comprising a first portion of the unreacted ammonia, and the product solution bottoms liquid comprising a remaining portion of the unreacted ammonia, and the ethanolamines; (e) separating, in a second ammonia stripping column, the product solution bottoms liquid into a second stripping column vapor overhead comprising the remaining portion of the unreacted ammonia, and a water-ethanolamines solution; (f) preparing a lean ammonia-water mixture in a second absorber from the second stripping column vapor overhead; (g) mixing the lean ammonia-water mixture with the water-ammonia mixture vapor overhead in a first absorber to prepare the water-ammonia solution; (h) separating, in a first evaporator, the water-ethanolamines solution into steam overhead and a concentrated water-ethanolamines solution; and (i) further concentrating the concentrated water-ethanolamines solution, in a second evaporator.