Process for manufacturing ethylene amines

Abstract

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.

Claims

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 ##STR00006## or a piperazine moiety of the formula ##STR00007## 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 ##STR00008##

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 ##STR00009## 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.

Description

EXAMPLE 1: MEG+EDA+EU AT DIFFERENT CO:AMINE-FUNCTIONAL COMPOUND MOLAR RATIOS

(1) Reaction mixtures were prepared comprising monoethylene glycol, ethylene diamine and ethylene urea. The molar ratio between amine-functional compound (the total of ethylene diamine and ethylene urea) and monoethylene glycol was 2:1. The amount of ethylene urea was selected such that the molar ratio of CO to amine-functional compounds (EDA+EU) was at the value specified in the table, varying between 0.05:1 and 1.5:1.

(2) The reaction mixtures were brought to a temperature of 270° C. under autogenous pressure, and allowed to react for 5 hours. After the reaction, the reaction mixtures comprised the following amount of (U)TETA compounds, calculated in mole percentage based on the starting amount of MEG in moles.

(3) TABLE-US-00001 Experiment 1.1 1.2 1.3 1.4 1.5 1.6 1.7 CO:(EDA + EU) 0.05 0.25 0.5 0.75 1.0 1.25 1.5 molar ratio Σ(U)TETAs 0.0 0.7 13.7 24.1 26.0 32.5 28.6

(4) As can be seen from this data, a CO:(EDA+EU) ratio of 0.05:1 or 0.25:1 is insufficient to obtain a meaningful conversion.

EXAMPLE 2: MEG+EDA+EU AT DIFFERENT REACTION TIMES

(5) Reaction mixtures were prepared comprising monoethylene glycol, ethylene diamine and ethylene urea. The molar ratio between amine compound (the total of ethylene diamine and ethylene urea) and monoethylene glycol was 3:1. The amount of ethylene urea was selected such that the molar ratio of CO to amine-functional compound was at the value specified in the table. Reactions were carried out at 270° C. for 5 hours and for 8 hours. After the reaction, the reaction mixtures comprised the following amount of (U)TETA compounds, determined as GC-FID data in wt. %.

(6) TABLE-US-00002 Experiment 2.1 2.2 2.3 2.4 Reaction time 5 hours 8 hours 5 hours 8 hours CO:(EDA + EU) 0.83 0.83 1 1 molar ratio Σ(U)TETAs 19.0 21.9 13.4 20.9

(7) As can be seen from this data, CO:(EDA+EU) molar ratios of 0.83:1 and 1:1 give good results. Longer reaction times lead to increased formation of (U)TETA compounds.

EXAMPLE 3: REACTION AND SUBSEQUENT HYDROLYSIS

(8) A reaction mixture was prepared comprising monoethylene glycol, ethylene diamine and ethylene urea. The molar ratio between amine compound (the total of ethylene diamine and ethylene urea) and monoethylene glycol was 3.5:1. The amount of ethylene urea was selected such that the molar ratio of CO to (EDA+EU) was 2.5:1. Reaction was carried out at 270° C. for 16 hours. The reaction product was contacted with a NaOH solution to hydrolyze the urea groups.

(9) The reaction mixture before hydrolysis contained about 26 wt. % of (U)TETA compounds, all in the form of urea derivatives. After hydrolysis, the reaction mixture contained about 25 wt. % of (U)TETA compounds, with only about 2% in the form of urea derivatives.

EXAMPLE 4: UDETA+CO2 AS STARTING MATERIAL

(10) A reaction mixture was prepared comprising monoethylene glycol, UDETA, and CO2 in a molar ratio of 1:2:2.5 (CO:amine-functional compound molar ratio=2.25:1). CO2 was added in gaseous form. The mixture was reacted at 270° C. for 5 hours under autogenous pressure. The resulting product comprised 43 wt. % of urea derivatives of pentaethylene hexamine.