Diethanolamine CAS 111-42-2

What is Diethanolamine?

Diethanolamine is the middle member of the ethanolamine family — a secondary amine carrying two hydroxyethyl groups, (HOCH₂CH₂)₂NH. It has one N-H bond, two hydroxyls, and a markedly different handling profile from either of its relatives.

The most immediately practical difference is physical. DEA melts at about 28 °C, which means that in most of the world it is a waxy white solid for part of the year and a viscous colourless liquid for the rest. Pure DEA is therefore shipped heated or handled as crystals, and an 85% aqueous solution is widely traded precisely because it stays liquid.

It is strongly hygroscopic, fully miscible with water, and darkens on air contact. The boiling point is high — around 268 °C — and the flash point near 137 °C, so it is combustible rather than flammable and handles comfortably from a fire standpoint.

Commercially, DEA sits in three places. It is a long-established acid gas treating solvent, particularly where some selectivity and lower corrosivity than MEA are wanted. It is the feedstock for morpholine and for a range of derivatives. And it forms water-soluble salts with acidic herbicides. Its historical use in surfactants and personal care has narrowed considerably in several markets because of the nitrosamine question that attaches to secondary amines, and that history is worth understanding before specifying it.

Why diethanolamine specifically

• Lower corrosivity than MEA in hot service. Secondary amine, slower kinetics, and a gentler effect on carbon steel — which is why it persisted in gas treating long after faster solvents appeared.
• Two hydroxyls and one N-H. The combination allows selective chemistry at either end and is what makes it the natural route to morpholine.
• Forms stable, soluble amine salts. Widely used to solubilise acidic agrochemical actives into sprayable concentrates.
• Higher capacity per mole than MEA. Carries more acid gas per unit of circulation in some service, offsetting its slower rate.

How DEA is Manufactured

Diethanolamine is made alongside MEA and TEA by reacting ethylene oxide with ammonia. The ratio of reactants decides which of the three dominates, and no plant makes one without making the others.

• Ethoxylation of ammonia. Aqueous ammonia is reacted with ethylene oxide. The mono product formed competes with ammonia for the next molecule of ethylene oxide, so di- and tri- products form in the same reactor as a matter of course.
• Ratio control. A plant configured for DEA runs a lower ammonia-to-ethylene-oxide ratio than one making MEA. Since the distribution is set by reaction stoichiometry rather than by selectivity, producers swing between products rather than making one exclusively.
• Ammonia and water removal. Excess ammonia is stripped and recycled and water is evaporated — the energy-intensive part of the process.
• Vacuum distillation. The three ethanolamines are separated under vacuum, which is necessary because they discolour and decompose at the temperatures atmospheric distillation would demand. Column performance sets colour and cross-contamination.

Typical Commercial Specification

Figures below are representative of standard commercial grade. Gas-treating, low-colour and 85% solution grades are available — send us the specification you work to and we will quote against it.

Physical & Chemical Properties

Reactivity in practice

One N-H and two hydroxyls, with the amine the weaker nucleophile of the ethanolamine family. Four reaction types cover most of its use:

• Acid gas absorption. The secondary amine forms a carbamate with carbon dioxide, more slowly than MEA but with useful capacity, and takes up hydrogen sulphide by proton transfer.
• Cyclodehydration to morpholine. Dehydrating DEA closes the ring to morpholine — one of the two industrial routes to that product, and a significant outlet for DEA.
• Salt formation. Neutralises acidic herbicides and other acids to give water-soluble amine salts used in sprayable agrochemical concentrates.
• Amidation and ethoxylation. Reacts with fatty acids to give dialkanolamides and with ethylene oxide at the hydroxyls — historically major surfactant routes, now restricted in several markets.

Diethanolamine vs Monoethanolamine and Triethanolamine

The three ethanolamines come off the same reactor and are separated by distillation, so they are routinely quoted together and routinely confused. Each additional hydroxyethyl group on the nitrogen raises the boiling point and the viscosity, lowers the basicity, and removes one N-H bond — and that last point decides most of the chemistry.

Stated plainly: monoethanolamine reacts fastest and strips hardest, which is why it dominates bulk carbon dioxide removal and why it costs the most energy to regenerate. Diethanolamine sits between the two and carries the nitrosamine consideration that follows every secondary amine. Triethanolamine has no N-H at all, so it cannot form a carbamate and acts as a base, an emulsifier precursor and a cement additive rather than as a bulk acid-gas absorbent. They are not interchangeable, and in gas treating the choice between them is a plant design decision.

Industries We Supply DEA To

The same molecule leaves our warehouse for very different factories. What changes between them is not the CAS number but the form — solid, melted or 85% solution — the grade, and the documentation each sector expects.

Where DEA is Used

DEA has a narrower set of markets than it once did, for reasons worth understanding. These are the end uses our customers buy it for, roughly in order of volume.

In gas treating

DEA has a long history in natural gas sweetening and refinery amine units. As a secondary amine it reacts with carbon dioxide more slowly than MEA, which costs absorber height, but it is less corrosive in hot service and less prone to certain degradation pathways, which saves on metallurgy and solvent losses. Where a stream carries carbonyl sulphide or carbon disulphide, DEA degrades less than MEA does. As with any amine solvent, iron and chloride in the make-up amine directly determine how long the inventory lasts.

In agrochemical formulation

Many herbicide actives are acids with poor water solubility, effectively unusable as sprayable products until neutralised. DEA forms stable, highly water-soluble salts with them, which is why it appears in a range of commercial concentrate formulations. The chemistry is simple neutralisation, so what matters on the certificate is assay, water content and colour rather than anything exotic.

As morpholine feedstock

Dehydrating diethanolamine closes the ring to morpholine. It is the older of the two industrial routes — the other starts from diethylene glycol — and it tends to leave higher residual sulphate in the morpholine because of the acid used. For a buyer of morpholine this is worth knowing, because it explains why morpholine specifications differ by producer.

The surfactant history and the nitrosamine question

DEA was once used extensively to make fatty dialkanolamides for shampoos, dish detergents and metalworking fluids. That use has narrowed substantially in several markets, because DEA is a secondary amine and can be nitrosated to N-nitrosodiethanolamine in the presence of nitrosating agents. Cosmetic regulations in a number of territories now restrict DEA and its fatty amides, and much of the metalworking fluid industry moved to alternatives. None of this makes DEA unusable — it remains a mainstream industrial chemical — but anyone specifying it for a consumer-contact application should confirm the current position at destination rather than relying on a historical formulation.

Quality Control & Testing

Every lot is released against a batch-specific Certificate of Analysis. The methods behind the numbers are standard across the industry, and we are happy to share them or to work to your own in-house test protocol.

• Assay and ethanolamine distribution — gas chromatography, quantifying MEA and TEA carry-over alongside the main component.
• Melting point — a fast, revealing check. A depressed melting point usually signals water or cross-contamination before any instrument confirms it.
• Water content — Karl Fischer titration. DEA is strongly hygroscopic and drifts once a container is opened, particularly when warm.
• Colour — APHA / Hazen on melted material against a standard. The ethanolamines darken on air contact, and heated storage accelerates it.
• Iron and chloride — critical for gas treating, where both drive corrosion and solvent degradation in a hot circuit.
• Specific gravity — a quick practical check correlating with water and cross-contamination.

Common Process Problems & Likely Causes

When DEA misbehaves in a plant, the cause is usually one of a short list of things. This table is the shortcut our technical desk works through before anyone opens a complaint file.

Packaging, Storage & Shipping

• Standard packing. 230 kg net in lined steel or HDPE drums, with 1000 L IBCs for larger users.
• Solution grade. 85% aqueous solution, which stays liquid at ordinary temperatures and is the practical choice for most plants that would otherwise be melting drums.
• Bulk packing. Heated road tankers and heated ISO tank containers for gas plants and continuous users.
• Melting and handling. Pure DEA is a solid below about 28 °C. Drum heaters, hot rooms or heated storage are normal, and lines need tracing and lagging. Heat gently and evenly — local overheating darkens the product.
• Materials of construction. Stainless steel or suitable lined vessels. Carbon steel is used in some service but corrodes more readily when the amine is hot or loaded with acid gas. Avoid copper, brass, bronze and aluminium.
• Oxygen exclusion. The ethanolamines oxidise and darken on air contact, particularly when warm. Nitrogen blanketing is standard for colour-sensitive grades and for any heated storage.
• Shelf life. Typically 12 months in unopened original packing under those conditions. Beyond that, re-test rather than assume.
• Nitrite segregation. As a secondary amine, DEA should be stored and handled well away from nitrites and other nitrosating agents. Treat this as a segregation rule rather than a precaution.
• Transport classification. Diethanolamine is generally not classified as dangerous goods for transport, though it is classified as hazardous for supply. Confirm the position against the current SDS for your destination and mode before booking.

Hazards & Safe Handling

Diethanolamine is corrosive to the eyes, harmful by several routes and carries a nitrosamine consideration as a secondary amine. It must be handled by trained personnel under a proper risk assessment. The classifications below are indicative — the current SDS supplied with your consignment is the governing document.

• Nitrosamine consideration. DEA is a secondary amine and can be nitrosated to N-nitrosodiethanolamine in the presence of nitrosating agents. This has driven restrictions on DEA and its fatty amides in cosmetics in several territories and substitution across much of the metalworking fluid industry. Keep nitrites out of the handling area and design formulations so the two cannot meet.
• Repeated exposure. DEA is classified in several systems for organ effects on prolonged or repeated exposure. That shifts the emphasis from acute splash protection toward controlling routine low-level contact over time — gloves that are actually changed, and procedures that do not rely on washing hands afterwards.
• Exposure control. Handle under local exhaust ventilation or in a closed system. Vapour pressure is very low at ambient, so skin and eye contact dominate — except in heated service, where mist and vapour become relevant.
• PPE. Chemical-resistant gloves, chemical goggles and face shield, chemical-resistant clothing.
• Hot material. Molten DEA and heated storage raise both the thermal burn risk and vapour exposure. Treat heated handling as a separate operation with its own controls.
• Incompatibilities. Strong oxidising agents, strong acids, acid chlorides, nitrites, and copper, brass, bronze and aluminium equipment.
• Spill response. Contain, absorb with inert material and collect in a labelled closed container. Solid material can be collected mechanically. Do not wash to drain.
• First aid. Remove contaminated clothing, wash skin with plenty of water, flush eyes for at least 15 minutes, and seek medical attention with the SDS to hand.

Regulatory & Compliance Notes

Diethanolamine is a long-established industrial chemical listed on the major national inventories, but it carries more regulatory history than its relatives — principally around nitrosamines and consumer products. The notes below are orientation rather than legal advice; confirm your own position with your regulatory adviser before importing.

• Inventory status. Listed on the principal chemical inventories in the major importing regions. Ask us for the inventory confirmation relevant to your destination country.
• Import registration. Several territories require the importer to hold a registration or notification before a consignment lands. Start that process early — it is the most common cause of delay at destination.
• Hazard communication. Supplied with an SDS compliant with the format applicable to your region, and labelled in line with the GHS classification for the product.
• Cosmetic restrictions. DEA and its fatty alkanolamides are restricted or prohibited in cosmetic products in several territories because of the nitrosamine concern. If your end use is consumer contact, confirm the current position at destination before specifying — historical formulations are not a guide.
• Nitrosamine limits in finished goods. Where a sector applies limits on nitrosatable amines or nitrosamine content — metalworking fluids and personal care in particular — build that assessment in at the design stage.
• Occupational classification. Classified in several systems for organ effects on repeated exposure, which affects labelling and workplace controls.
• Transport. Generally not classified as dangerous goods for transport, though classified as hazardous for supply. Confirm the position against the current SDS for your destination and mode.

We Supply DEA Worldwide

Chelora Chemicals is a supplier and export partner, not a single-plant trader. We ship Diethanolamine from India to customers across Asia, Europe, the Middle East, Africa, and North and South America, handling the export documentation, dangerous-goods paperwork and freight so the material arrives ready to use.

• Incoterms. EXW, FOB, CIF, CFR and DAP quoted to suit your purchasing terms and freight arrangements.
• Ports. Regular shipments through Nhava Sheva (JNPT) and Mundra, with other Indian ports arranged where it suits the routing.
• Documentation. Commercial invoice, packing list, certificate of origin, COA, SDS and dangerous-goods declaration issued as a complete set.
• Flexible volumes. A single drum for laboratory qualification, through LCL consolidations, up to repeat full loads on a supply contract.
• Supply continuity. Because we are independent of any one producer, a plant turnaround or a shipping disruption at one source does not have to become your stock-out.

Buying DEA from Chelora

We are an independent sourcing and supply partner. For DEA that means two practical decisions before quoting: which physical form your plant can actually handle, and whether the end use brings consumer-product regulation into play.

• Documentation on every lot. Batch-specific COA, current SDS and TDS issued with the consignment, not weeks afterward.
• Multiple forms. Solid, melted bulk and 85% solution, matched to how your plant handles material.
• Samples before commitment. Trial quantities for process qualification ahead of a commercial order.
• Quantities. From a single 230 kg drum through to heated tank loads on contract supply.
• Export experience. Full documentation, packing and labelling handled for sea and road freight to any destination.
• Related intermediates. MEA, TEA, the isopropanolamines, morpholine and the wider alkanolamine range from one supplier.

How ordering works

• Send the enquiry. Product, grade or specification, quantity, destination port and the Incoterm you buy on. If you have a spec sheet, attach it — it saves a round trip.
• We quote. Price, lead time, packing and a sample COA, normally within one working day.
• Sample and qualify. For first orders or critical applications, we send a trial quantity so your lab can sign off before you commit.
• Confirm the order. Proforma invoice issued; payment terms agreed against the volume and the relationship.
• Production and QC. Material allocated and released against a batch-specific COA, with a pre-shipment sample where the application calls for it.
• Ship and document. Packed, labelled and loaded with the full export and dangerous-goods document set, and tracked through to arrival.

Related Alkanolamines & Intermediates

Buyers of DEA usually source several of these alongside it. Consolidating them on one order cuts freight cost and gives you a single point of contact for documentation.