Methyldiethanolamine

Last updated
Methyldiethanolamine
Methyldiethanolamine.svg
Names
Preferred IUPAC name
2,2′-(Methylazanediyl)di(ethan-1-ol)
Other names
Bis(2-hydroxyethyl)(methyl)amine
Identifiers
3D model (JSmol)
1734441
ChEMBL
ChemSpider
ECHA InfoCard 100.003.012 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 203-312-7
MeSH N-methyldiethanolamine
PubChem CID
RTECS number
  • KL7525000
UNII
  • InChI=1S/C5H13NO2/c1-6(2-4-7)3-5-8/h7-8H,2-5H2,1H3 X mark.svgN
    Key: CRVGTESFCCXCTH-UHFFFAOYSA-N Yes check.svgY
  • CN(CCO)CCO
Properties
C5H13NO2
Molar mass 119.164 g·mol−1
AppearanceColorless liquid
Odor Ammoniacal
Density 1.038 g mL−1
Melting point −21.00 °C; −5.80 °F; 252.15 K
Boiling point 247.1 °C; 476.7 °F; 520.2 K
Miscible
Vapor pressure 1 Pa (at 20 °C)
1.4694
Viscosity 101 mPa s (at 20°C)
Pharmacology
Oral
Hazards
GHS labelling:
GHS-pictogram-exclam.svg
Warning
H319
P305+P351+P338
NFPA 704 (fire diamond)
1
1
0
Flash point 127 °C (261 °F; 400 K)
410 °C (770 °F; 683 K)
Explosive limits 1.4-8.8%
Lethal dose or concentration (LD, LC):
1.945 g kg−1(oral, rat)
Related compounds
Related alkanols
Related compounds
Diethylhydroxylamine
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
X mark.svgN  verify  (what is  Yes check.svgYX mark.svgN ?)

Methyldiethanolamine, also known as N-methyl diethanolamine and more commonly as MDEA, is the organic compound with the formula CH3N(C2H4OH)2. It is a colorless liquid with an ammonia odor. It is miscible with water, ethanol and benzene. A tertiary amine, it is widely used as a sweetening agent in chemical, oil refinery, syngas production and natural gas. [1]

Contents

Similar compounds are monoethanolamine (MEA), a primary amine, and diethanolamine (DEA), a secondary amine, both of which are also used for amine gas treating. MDEA's defining characteristic when compared to these other amines is its ability to preferentially remove H2S (and strip CO2) from sour gas streams. [1]

MDEA's popularity as a solvent for gas treating stems from several advantages it has when compared to other alkanolamines. One of these advantages is a low vapor pressure, which allows for high amine compositions without appreciable losses through the absorber and regenerator. MDEA is also resistant to thermal and chemical degradation and is largely immiscible with hydrocarbons. MDEA is a common base note in perfumes to allow the fragrance to last. Lastly, MDEA has a relatively low heat of reaction with hydrogen sulfide and carbon dioxide, which allows for lower reboiler duties, thus lower operating costs.

MDEA blends

MDEA is less reactive towards CO2, but has an equilibrium loading capacity approaching 1 mole CO2 per mole amine. [2] It also requires less energy to regenerate. [2] To combine the advantages of MDEA and the smaller amines, MDEA is usually mixed with a catalytic promoter such as piperazine, PZ, or a fast reacting amine such as MEA to retain reactivity, but lower regeneration costs. Activated MDEA or aMDEA uses piperazine as a catalyst to increase the speed of the reaction with CO2. It has been commercially successful. [3] Many tests have been done on the performance of MDEA/MEA or MDEA/piperazine mixtures compared to single amines. CO2 production rates were higher than MEA for the same heat duty and total molar concentration when experiments were performed in the University of Regina pilot plant, which is a modeled after a natural gas plant. There were also insignificant trace amounts of degradation products detected. [2] However, when the same control variables and tests were conducted at the Boundary Dam Power Station plant, the CO2 production rate for the mixed solvent was lower than MEA. [2] This was a result of the reduction in the capacity of the solvent to absorb CO2 after degradation. Because the Boundary Dam plant is a coal-fired power plant, it operates under harsher environments and produces an impure flue gas containing, fly ash, SO2, and NO2 that are fed into carbon capture. Even with flue gas pretreatment, there is still enough to produce degradation products such as straight chain amines and sulfur compounds, which accumulate so it is no longer possible to regenerate MEA and MDEA. [2] For these blends to be successful in reducing heat duty, their chemical stabilities must be maintained.

Degradation

Main oxidative degradation products of MDEA include monoethanol amine (MEA), methyl-aminoethanol (MAE), diethanolamine (DEA), amino acids bicine, glycine and hydroxyethyl sarcosine (HES), formyl amides of MAE and DEA, ammonia, and stable salts formate, glycolate, acetate, and oxalate. [4] In an industrial plan that utilizes MDEA, oxidative degradation is most likely to shift to the cross exchanger where temperatures are greater than 70 °C. [4] Higher temperatures and higher CO2 loading accelerate the rate of degradation, resulting in an increase of alkalinity loss as well as total formate production. While MDEA is more resistant to degradation as a standalone compared to MEA, MDEA is preferentially degraded when in an MDEA/MEA blend. [4] Because of the formation of DEA and MAE, which could form nitroso-compounds or diethylnitrosamine and diethylnitraine, the blend could potentially have an adverse impact in terms of atmospheric admissions. [4] In the Boundary Dam plant, emissions increased when CO2 loading of lean amine increased for the blend and MEA. [4] However, decreasing the lean loading increases the reboiler heat duty, which results in an obvious tradeoff between emissions and heat duty or energy costs.

This compound should not be confused with the recreational drug methylenedioxyethylamphetamine which is also abbreviated MDEA.

Production

MDEA is produced by ethoxylation of methylamine using ethylene oxide: [1]

CH3NH2 + 2 C2H4O → CH3N(C2H4OH)2

Another route involves hydroxymethylation of diethanolamine followed by hydrogenolysis.

See also

Related Research Articles

In chemistry, amines are compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are formally derivatives of ammonia, wherein one or more hydrogen atoms have been replaced by a substituent such as an alkyl or aryl group. Important amines include amino acids, biogenic amines, trimethylamine, and aniline. Inorganic derivatives of ammonia are also called amines, such as monochloramine.

<span class="mw-page-title-main">Ethanolamine</span> Chemical compound

Ethanolamine is an organic chemical compound with the formula HOCH
2
CH
2
NH
2
or C
2
H
7
NO
. The molecule is bifunctional, containing both a primary amine and a primary alcohol. Ethanolamine is a colorless, viscous liquid with an odor reminiscent of ammonia. ETA molecules are a component in the formation of cellular membranes and are thus a molecular building block for life. It was thought to exist only on Earth and on certain asteroids, but in 2021 evidence was found that ETA molecules exist in interstellar space.

<i>N</i>-Methylethanolamine Chemical compound

N-Methylethanolamine is an alkanolamine with the formula CH3NHCH2CH2OH. It is flammable, corrosive, colorless, viscous liquid. It is an intermediate in the biosynthesis of choline.

<span class="mw-page-title-main">Formamide</span> Chemical compound

Formamide is an amide derived from formic acid. It is a colorless liquid which is miscible with water and has an ammonia-like odor. It is chemical feedstock for the manufacture of sulfa drugs and other pharmaceuticals, herbicides and pesticides, and in the manufacture of hydrocyanic acid. It has been used as a softener for paper and fiber. It is a solvent for many ionic compounds. It has also been used as a solvent for resins and plasticizers. Some astrobiologists suggest that it may be an alternative to water as the main solvent in other forms of life.

In industrial chemistry, coal gasification is the process of producing syngas—a mixture consisting primarily of carbon monoxide (CO), hydrogen, carbon dioxide, methane, and water vapour —from coal and water, air and/or oxygen.

<span class="mw-page-title-main">Piperazine</span> Chemical compound

Piperazine is an organic compound that consists of a six-membered ring containing two nitrogen atoms at opposite positions in the ring. Piperazine exists as small alkaline deliquescent crystals with a saline taste.

Amine gas treating, also known as amine scrubbing, gas sweetening and acid gas removal, refers to a group of processes that use aqueous solutions of various alkylamines (commonly referred to simply as amines) to remove hydrogen sulfide (H2S) and carbon dioxide (CO2) from gases. It is a common unit process used in refineries, and is also used in petrochemical plants, natural gas processing plants and other industries.

<span class="mw-page-title-main">Flue gas</span> Gas exiting to the atmosphere via a flue

Flue gas is the gas exiting to the atmosphere via a flue, which is a pipe or channel for conveying exhaust gases from a fireplace, oven, furnace, boiler or steam generator. Quite often, the flue gas refers to the combustion exhaust gas produced at power plants. Its composition depends on what is being burned, but it will usually consist of mostly nitrogen derived from the combustion of air, carbon dioxide, and water vapor as well as excess oxygen. It further contains a small percentage of a number of pollutants, such as particulate matter, carbon monoxide, nitrogen oxides, and sulfur oxides.

<span class="mw-page-title-main">Thermal decomposition</span> Chemical decomposition caused by heat

Thermal decomposition is a chemical decomposition caused by heat. The decomposition temperature of a substance is the temperature at which the substance chemically decomposes. The reaction is usually endothermic as heat is required to break chemical bonds in the compound undergoing decomposition. If decomposition is sufficiently exothermic, a positive feedback loop is created producing thermal runaway and possibly an explosion or other chemical reaction.

<span class="mw-page-title-main">Diethanolamine</span> Chemical compound

Diethanolamine, often abbreviated as DEA or DEOA, is an organic compound with the formula HN(CH2CH2OH)2. Pure diethanolamine is a white solid at room temperature, but its tendencies to absorb water and to supercool meaning that it is often encountered as a colorless, viscous liquid. Diethanolamine is polyfunctional, being a secondary amine and a diol. Like other organic amines, diethanolamine acts as a weak base. Reflecting the hydrophilic character of the secondary amine and hydroxyl groups, DEA is soluble in water. Amides prepared from DEA are often also hydrophilic. In 2013, the chemical was classified by the International Agency for Research on Cancer as "possibly carcinogenic to humans" (Group 2B).

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Hot-melt adhesive (HMA), also known as hot glue, is a form of thermoplastic adhesive that is commonly sold as solid cylindrical sticks of various diameters designed to be applied using a hot glue gun. The gun uses a continuous-duty heating element to melt the plastic glue, which the user pushes through the gun either with a mechanical trigger mechanism on the gun, or with direct finger pressure. The glue squeezed out of the heated nozzle is initially hot enough to burn and even blister skin. The glue is sticky when hot, and solidifies in a few seconds to one minute. Hot-melt adhesives can also be applied by dipping or spraying, and are popular with hobbyists and crafters both for affixing and as an inexpensive alternative to resin casting.

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A thermal oxidizer is a process unit for air pollution control in many chemical plants that decomposes hazardous gases at a high temperature and releases them into the atmosphere.

<span class="mw-page-title-main">Aminoethylpiperazine</span> Chemical compound

Aminoethylpiperazine (AEP) is a derivative of piperazine. This ethyleneamine contains three nitrogen atoms; one primary, one secondary and one tertiary. It is a corrosive organic liquid and can cause second or third degree burns. Aminoethylpiperazine can also cause pulmonary edema as a result of inhalation. It is REACH and TSCA registered.

A carbon dioxide scrubber is a piece of equipment that absorbs carbon dioxide (CO2). It is used to treat exhaust gases from industrial plants or from exhaled air in life support systems such as rebreathers or in spacecraft, submersible craft or airtight chambers. Carbon dioxide scrubbers are also used in controlled atmosphere (CA) storage. They have also been researched for carbon capture and storage as a means of combating climate change.

Glycol dehydration is a liquid desiccant system for the removal of water from natural gas and natural gas liquids (NGL). It is the most common and economical means of water removal from these streams. Glycols typically seen in industry include triethylene glycol (TEG), diethylene glycol (DEG), ethylene glycol (MEG), and tetraethylene glycol (TREG). TEG is the most commonly used glycol in industry.

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<span class="mw-page-title-main">Boundary Dam Power Station</span> Power station in Saskatchewan, Canada

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The use of ionic liquids in carbon capture is a potential application of ionic liquids as absorbents for use in carbon capture and sequestration. Ionic liquids, which are salts that exist as liquids near room temperature, are polar, nonvolatile materials that have been considered for many applications. The urgency of climate change has spurred research into their use in energy-related applications such as carbon capture and storage.

References

  1. 1 2 3 Matthias Frauenkron, Johann-Peter Melder, Günther Ruider, Roland Rossbacher, Hartmut Höke "Ethanolamines and Propanolamines" in Ullmann's Encyclopedia of Industrial Chemistry 2002, Wiley-VCH, Weinheim. doi : 10.1002/14356007.a10_001
  2. 1 2 3 4 5 Idem, Raphael (2006). "Pilot Plant Studies of the CO2 Capture Performance of Aqueoues MEA and Mixed MEA/MDEA Solvents at the University of Regina CO2 Capture Technology Development Plant and the Boundary Dam CO2 Capture Demonstration Plant". Ind. Eng. Chem. Res. 45 (8): 2414–2420. doi:10.1021/ie050569e.
  3. "Piperazine – Why It's Used and How It Works" (PDF). The Contactor. Optimised Gas Treating, Inc. 2 (4). 2008. Archived from the original (PDF) on 2014-11-29. Retrieved 2013-10-23.
  4. 1 2 3 4 5 Boot-Handford, M.E. (2014). "Carbon capture and storage update". Energy Environ. Sci. 7 (1): 130–189. doi:10.1039/c3ee42350f. S2CID   97132693.