Ethanolamines
Ethanolamines are made by reacting ethylene oxide with ammonia in an aqueous solution. The product distribution of MEA, DEA, TEA can be adjusted by varying the ammonia to EO ratio and by recycle of the MEA and or DEA to achieve a heavy distribution high in TEA. The reaction is adiabatic and non catalytic. Reaction condition and distillation temperatures have to be controlled in a narrow range to avoid color problem with the products, particularly TEA. Description: Ethylene Oxide is added to a solution of ammonia and water along with any amine recycle, and is heated to reaction temperature and fed to the reactor (1). Multiple reactors in series are used with inter-cooling to control the maximum temperature rise in the reactors. A portion of the EO is added to each reactor. The final reactor effluent is fed to a steam stripper (2) to remove the excess unreacted ammonia which is absorbed in water (3) and recycled back to the reactor with any make-up ammonia required. The ammonia free solution is the sent to a multi-effect evaporator (4) to remove the bulk of the water. The partially dried amine solution is then fully dried in a Drying Column (5) before it is sent to the amines distillation system (6,7,8) where the MEA, DEA and TEA products are recovered. Some of the lighter amines MEA and DEA can be recycle back to the reactors to increase the production of TEA if a heavier distribution is required. Advantages of SD Process :
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