Diethylethanolamine (DEAE)

📌 What Makes DEAE a "Sterically Hindered Amine" - and Why It Matters for Gas Treatment

When CO₂ reacts with a primary amine (MEA) or unhindered secondary amine (DEA), it forms a thermally stable carbamate salt - stoichiometrically limiting loading to ~0.5 mol CO₂ per mol amine, and requiring high reboiler temperatures (120–130 °C) to break the carbamate and release the gas. DEAE's two bulky ethyl groups create steric congestion around the nitrogen, preventing stable carbamate formation. Instead, CO₂ forms labile bicarbonate intermediates via hydration, raising the theoretical loading capacity to ~1.0 mol CO₂ per mol amine and releasing CO₂ at significantly lower regeneration temperatures (95–110 °C). This directly translates to lower steam consumption, smaller reboiler size, and reduced operating costs in industrial amine gas treatment units. DEAE is frequently blended with MDEA or activated with piperazine to optimize both absorption kinetics and capacity.

What is Diethylethanolamine (DEAE) and what is it used for?

Diethylethanolamine (DEAE, CAS 100-37-8) is a sterically hindered tertiary alkanolamine with formula C₆H₁₅NO, also known as N,N-Diethylaminoethanol. Its primary uses are: (1) acid gas removal (CO₂/H₂S) in natural gas sweetening, LNG purification, and industrial CO₂ capture, where its high loading capacity and low regeneration energy offer significant operating cost advantages; (2) volatile neutralizing amine for boiler water and steam condensate corrosion protection; (3) neutralizing amine for waterborne coatings, inks, and resin systems; (4) pharmaceutical and fine chemical intermediate; (5) corrosion inhibitor component; and (6) surfactant building block.

Why is DEAE called a "sterically hindered amine" and why does it matter for gas treatment?

The two ethyl groups flanking DEAE's nitrogen atom create steric bulk that prevents the nitrogen from forming stable carbamate salts with CO₂ - unlike primary amines (MEA) or unhindered secondary amines (DEA). Instead, CO₂ reacts via hydration to form labile bicarbonate intermediates, which raises the theoretical CO₂ loading to ~1.0 mol per mol amine (vs. ~0.5 for MEA carbamate chemistry) and releases CO₂ at lower regeneration temperatures (95–110 °C vs. 120–130 °C for MEA). In practical gas treatment terms, this means higher solvent throughput, smaller absorber volume, lower reboiler duty, and significantly lower steam consumption - all of which reduce capital and operating costs for the plant operator.

How does DEAE compare to DMEA as a neutralizing amine for waterborne coatings?

Both DEAE and DMEA are tertiary amines that neutralize waterborne coating resins and evaporate during film formation. The key difference is their boiling point and evaporation rate: DEAE (bp 162 °C) evaporates more slowly than DMEA (bp 134 °C) during the drying process. This slower release of DEAE provides a more gradual pH reduction during film formation, which is beneficial for coating systems sensitive to rapid pH drops, improves open time and flow-leveling in architectural and industrial coatings, and reduces the risk of amine blush and surface defects in multi-coat systems. DMEA is preferred when faster film hardening and higher early water resistance are priorities; DEAE is preferred for improved application properties and flow.

How is DEAE used in boiler water and steam condensate treatment?

In steam boiler systems, dissolved CO₂ forms carbonic acid in the condensate, driving pH down to 5.5–6.5 and causing corrosion of condensate pipelines and heat exchangers. DEAE is injected into the steam line or feedwater, where it volatilizes and distributes throughout the steam and condensate system via its high vapor-liquid distribution coefficient. Upon condensing, DEAE neutralizes carbonic acid and raises condensate pH to the protective range (8.5–9.5). Its moderate boiling point ensures effective distribution throughout the entire return system, not just at the injection point. DEAE is compatible with hydrazine, morpholine, cyclohexylamine, and oxygen scavenger packages, and is suitable for use in carbon steel condensate systems.

What purity grade does SinoLook Chem supply for DEAE?

SinoLook Chem supplies DEAE at ≥99.0% purity (GC assay), with typical batch results of 99.4–99.7%. Water content is ≤0.2% (typically 0.08–0.14%), color is ≤20 APHA (typically ≤10), and residue on ignition is ≤0.01% (<0.005% typical). A pharmaceutical grade (≥99.5%) is available with dedicated batch documentation including impurity profiles, residual solvent analysis, and ICH Q7 compliance support. DMF filing assistance is available on request.

What are the storage and handling requirements for DEAE?

DEAE has a flash point of 55–60 °C and should be stored as a flammable liquid in a cool (5–35 °C), well-ventilated, explosion-proof area away from heat sources, sparks, and open flames. Keep away from strong acids, strong oxidizers, and acid chlorides. Use UN-approved steel drums or IBC containers; avoid copper and copper alloys. Wear chemical-resistant gloves (nitrile or butyl rubber), safety goggles, face shield, and chemical apron when handling. Use antistatic equipment to prevent electrostatic ignition; local exhaust ventilation is recommended.

What is the Diethylethanolamine HS code?

Diethylethanolamine (CAS 100-37-8) is classified under HS code 2922.19 (amino alcohols - other, other than those containing only oxygen-containing groups as heteroatoms, their ethers and esters; salts thereof). Always confirm the applicable tariff code with your local customs authority, as classifications may vary by jurisdiction.

How do I place an order or request a free sample?

Free 500 g – 1 kg samples with full CoA are available for qualified buyers. To order or request a sample:

• Step 1: Contact us by email, WhatsApp, or website with your requirements (quantity, purity grade, packaging, delivery terms, destination).
• Step 2: Receive a detailed, customized quote within 12 hours including price, lead time, and logistics options.
• Step 3: Request a free sample (500 g – 1 kg) with full CoA for quality validation in your specific application.
• Step 4: Confirm your order - our team handles production scheduling, packaging, documentation, and freight booking end-to-end.
• Step 5: Receive your shipment on time with full traceability documentation and post-delivery technical and regulatory support.