Process for manufacturing ethylene amines
A process for preparing polyethyleneamines of formula NH2-(CH2-CH2-NH-)pH wherein p is at least 3 and wherein one or more —NH-CH2-CH2-NH— units may be piperazine units and/or ethylene urea derivatives of these compounds, includes reacting monoethylene glycol with an amine-functional compound having at least two —NH— units, of which at least one is selected from primary amine groups and cyclic secondary amine groups, in the presence of a carbon oxide-delivering agent. The amine-functional compound includes at least one —NH-CH2-CH2-NH— unit, and one or more —NH-CH2-CH2-NH— units may be in the form of cyclic ethylene urea moieties, piperazine moieties, or linear ethylene urea moieties. The molar ratio of amine-functional compound to monoethylene glycol is above 1.2:1 and the molar ratio of carbon oxide delivering agent to —NH-CH2-CH2-NH— units is at least 0.5:1. The process makes it possible to obtain ethylene amines and derivatives thereof without using ammonia or metal-containing catalysts.
1. A process for preparing polyethyleneamines of the formula NH2-(CH2-CH2-NH-)pH wherein p is at least 3, comprising the step of reacting monoethylene glycol with an amine-functional compound comprising at least two —NH— units of which at least one is selected from the group of primary amine groups and cyclic secondary amine groups, in the presence of a carbon oxide-delivering agent, the amine-functional compound comprising at least one —NH-CH2-CH2-NH— unit, wherein at least one —NH-CH2-CH2-NH-unit in the amine-functional compound is present in the form of a cyclic ethylene urea moiety of the formula
or a piperazine moiety of the formula
wherein
the molar ratio of amine-functional compound to monoethylene glycol is above 1.2:1 and
the molar ratio of carbon oxide-delivering agent to —NH-CH2-CH2-NH— in the amine-functional compound is at least 0.5:1,
wherein a —NH-CH2-CH2-NH— unit is a unit which can form an ethylene urea unit in the amine-functional compound, and
wherein the carbon oxide delivering agent is selected from the group of carbon dioxide, the CO adduct of monoethylene glycol selected from the group of cyclic ethylene carbonate and HO-CH2-CH2-O—C(O)—O-CH2-CH2-OH, and urea-derivatives of ethylene amine compounds.
2. The process according to claim 1 , wherein the carbon oxide-delivering agent is selected from the group of carbon dioxide and ethylene urea (EU) of the formula
3. The process according to claim 1 , wherein the molar ratio of amine-functional compound to monoethylene glycol is above 1.5:1.
4. The process according to claim 1 , wherein the molar ratio of carbon oxide-delivering agent to —NH-CH2-CH2-NH— units in the amine-functional compound is at least 0.5:1.
5. The process according to claim 4 , wherein the molar ratio of carbon oxide-delivering agent to —NH-CH2-CH2-NH— units in the amine-functional compound is between from 0.7:1 to 3:1.
6. The process according to claim 1 , wherein at least 50% of the CO is added in the form of the CO adduct of monoethylene glycol selected from the group of cyclic ethylene carbonate and HO-CH2-CH2-O—C(O)—O-CH2-CH2-OH, or in the form of urea-derivatives of ethylene amine compounds.
7. The process according to claim 1 , wherein the amine-functional compound comprises ethylene diamine (EDA) provided in the form of EDA, in the form of the urea derivative ethylene urea (EU) having the formula
or as a mixture thereof, and the reaction product comprises triethylenetetramine (TETA) of the formula NH2-(CH2-CH2-NH-)p-H wherein p is 3.
8. The process according to claim 1 , wherein the amine-functional compound comprises diethylene triamine (DETA) provided as DETA, as the urea adduct thereof (UDETA), or a mixture thereof, and the reaction product comprises pentaethylene hexamine (PEHA) of the formula NH2-(CH2-CH2-NH-)p-H wherein p is 5.
9. The process according to claim 1 , wherein the amine-functional compound comprises piperazine (PIP) and the reaction product comprises HN(CH2-CH2)2N-CH2-CH2-N(CH2-CH2)2NH.
10. The process according to claim 1 , wherein the reaction product is subjected to a hydrolysis reaction to convert the urea adducts present therein into ethylene amines.
11. The process according to claim 1 , wherein the molar ratio of amine-functional compound to monoethylene glycol is above 1.7:1.
12. The process according to claim 1 , wherein the molar ratio of amine-functional compound to monoethylene glycol is at most 5:1.
13. The process according to claim 1 , wherein the molar ratio of amine-functional compound to monoethylene glycol is at most 3:1.
14. The process according to claim 1 , wherein the molar ratio of carbon oxide-delivering agent to —NH-CH2-CH2-NH— units in the amine-functional compound is at least 1:1.
15. The process according to claim 1 , wherein the molar ratio of carbon oxide-delivering agent to —NH-CH2-CH2-NH— units in the amine-functional compound is at most 5:1.
16. The process according to claim 1 , wherein the molar ratio of carbon oxide-delivering agent to —NH-CH2-CH2-NH— units in the amine-functional compound is at most 3:1.
17. The process according to claim 4 , wherein the molar ratio of carbon oxide-delivering agent to —NH-CH2-CH2-NH— units in the amine-functional compound is between from 0.9:1 to 2:1.
18. The process according to claim 4 , wherein the molar ratio of carbon oxide-delivering agent to —NH-CH2-CH2-NH— units in the amine-functional compound is between from 1.1:1 to 1.75:1.
19. The process according to claim 1 , wherein at least 75% of the CO is added in the form of the CO adduct of monoethylene glycol selected from the group of cyclic ethylene carbonate and HO-CH2-CH2-O—C(O)—O-CH2-CH2-OH, or in the form of urea derivatives of ethylene amine compounds.
20. The process according to claim 1 , wherein at least 95% of the CO is added in the form of the CO adduct of monoethylene glycol selected from the group of cyclic ethylene carbonate and HO-CH2-CH2-O—C(O)—O-CH2-CH2-OH, or in the form of urea derivatives of ethylene amine compounds.