Process for preparing alkanolamines
AssigneeMitsui Toatsu Chemicals, Inc.
InventorsHiroyoshi Watanabe, Mutsuo Matsumura, Takashi Ohkawa, Kenji Suzuki
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Abstract
A process for preparing alkanolamines which comprises steps of reacting ammonia with an alkylene oxide in the presence of a carbonate of ammonia to obtain a crude alkanolamine solution, distilling off ammonia, carbon dioxide and water to regulate the content of carbon dioxide in the crude alkanolamine solution to 1% by weight or less, and distilling the crude alkanolamine solution to separate and collect the alkanolamines, whereby the production ratio of a monoalkanolamine can be increased and impurities can be decreased.
Claims21
A process for preparing alkanolamines which comprises
- a) a step of reacting ammonia with an alkylene oxide in the presence of a carbonate of ammonia to obtain a crude alkanolamine solution,
- b) a step of distilling off ammonia, carbon dioxide and water to regulate the content of carbon dioxide in the crude alkanolamine solution to 1% by weight or less, and
- c) a step of distilling the crude alkanolamine solution to separate and collect the alkanolamines.
A process for preparing alkanolamines which comprises
- a) a step of reacting ammonia with an alkylene oxide in the presence of a carbonate of ammonia to obtain a crude alkanolamine solution,
- b) a step of subjecting the obtained crude alkanolamine solution to a heat treatment in a range of from 160.degree. to 220.degree. C. in the presence of water, distilling off carbon dioxide at a temperature equal to or higher than the heat treatment temperature, and then distilling off water to regulate the content of carbon dioxide in the crude alkanolamine solution to 1% by weight or less, and
- c) a step of distilling the crude alkanolamine solution to separate and collect the alkanolamines.
A process for preparing alkanolamines which comprises
- a) a step of reacting ammonia with an alkylene oxide in the presence of a carbonate of ammonia to obtain a crude alkanolamine solution,
- b) a step of reacting the obtained crude alkanolamine solution with a base in a range of from 140.degree. to 200.degree. C. in the presence of water, and then distilling off water to regulate the content of carbon dioxide in the crude alkanolamine solution to 1% by weight or less, and
- c) a step of distilling the crude alkanolamine solution to separate and collect a monoalkanolamine.
Dependencies are inferred from the claim text.