2 Methyl diethanolamine

Activated tertiary amines such as triethanolamine (TEA) and methyl diethanolamine (MDEA) have gained wide acceptance for CO2 removal. These materials require very low regeneration energy because of weak CO2 amine adduct formation, and do not form carbamates or other corrosive compounds (53). Hybrid CO2 removal systems, such as MDEA —sulfolane—water and DIPA—sulfolane—water, where DIPA is diisopropylamine, are aqueous alkaline solutions in a nonaqueous solvent, and are normally used in tandem with other systems for residual clean-up. Extensive data on the solubiUty of acid gases in amine solutions are available (55,56). 

For many years, nearly all the amine units were using monoethanola-mine (MEA) or diethanolamine (DEA). However, in recent years the use of tertiary amines such as methyl diethanolamine (MDEA) has increased. These solvents are generally less corrosive and require less energy to regenerate. They can be formulated for specific gas recovery requirements. 

Absorbents based on a variety of amines are by far the most common. Amines that have been used include monoethanolamine (MEA), diethanolamine (DEA), triethanolamine (TEA), diisopropanolamine (DIPA), methyl diethanolamine (MDEA), and digly-colamine (DGA). C02 is typically absorbed at 80-140°F temperature and up to 1000 psig pressure by chemically reacting with the basic amine functional group in the absorbent, for example, primary amine, MEA, reacts with C02 by the following reaction forming a carbamate salt ... 

Adip [Possibly an acronym of DIPA, di-isopropanolamine] A process for removing hydrogen sulfide, mercaptans, carbonyl sulfide, and carbon dioxide from refinery streams by extraction into an aqueous solution of di-isopropanolamine or methyl diethanolamine. Developed and licensed by the Shell Oil Company, Houston, TX. More than 320 units were operating in 1992. 

HS A family of gas purification processes developed by Union Carbide Corporation, based on the use of proprietary solvents known as UCARSOLs. UCARSOL HS-101, is based on methyl diethanolamine and is used for removing hydrogen sulfide and carbon dioxide from other gases. Ucarsol LH-101 is used in its Cansolv system for flue-gas desulfurization. 

MDEA [Methyl diethanolamine] A general name for processes using methyl diethanolamine for absorbing hydrogen sulfide and carbon dioxide from other gases. See also Activated MDEA. 

Resulf A process for removing residual sulfur compounds from refinery tailgases. They are hydrogenated to hydrogen sulfide, which is absorbed in an aqueous solution of an amine such as methyl diethanolamine. Licensed by TPA. 

UCAR [Union Carbide Carbon dioxide] A process for removing carbon dioxide from gas streams by scrubbing with methyl diethanolamine. Use of a proprietary corrosion inhibitor permits higher concentrations of the amine to be used than in similar processes. 

Irradiation in the presence of MDEA completely inhibits the formation of products. The amine quenches the fluorescence of Eosin with a rate constant of 8 x 108 M-1s-1 and quenches the Eosin triplet with a rate two orders of magnitude lower. A summary of rate constants for the decay of the triplet is presented in Table 8. In addition to the reactions shown in Scheme 3, with Am = (V-methyl diethanolamine, the rate constants for reaction of PDO with Eosin triplet and semioxidized Eosin radical in aqueous solution (Eqs. 19 and 20) are included in the table. 

The cooled process gas that leaves the Syngas Scrubber is fed to the Amine unit. The amine unit consists of an absorption-stripping system plus associated equipment. In this system a circulating amine stream (activated MDEA - or Methyl Diethanolamine) absorbs the C02 in the C02 Absorber. The amine is regenerated in the C02 Stripper with the C02 being recycled to the compressor. 

The aMDEA (Activated Methyl Diethanolamine) process removes CO2, H2S and trace sulfur compounds from natural gas and syngas via a pressurized wash with activated diethanolamine. This process was developed by BASF. The first unit was started up in 1971 in Germany and in 2002 it was used in more than 140 plants with 20 more under construction1. About 75 of these plants involve another process technology (MEA, DEA, Benfield, etc.) that was modified to use the aMDEA technology. 

In an amine system, one way to increase absorption is to increase amine concentration. A higher amine concentration requires 1) more extensive filtration to keep the solution clean and 2) the addition of corrosion inhibitors and to minimize corrosion. Another option is to change from monoethanolamine (MEA) to methyl diethanolamine (MDEA)86. 

Hence, activated tertiary amines such as triethanolamine (TEA) and methyl diethanolamine (MDEA) have now gained wide acceptance for CO2 removal. These materials require very... 

In the sixth official proficiency test, two laboratories failed to find EDEA and methyl diethanolamine (CAS 105-59-9) in a water sample. One of the laboratories performed only C18 SPE for the water sample and did not carry out an evaporation-derivatization procedure. The other laboratory first performed dichloromethane extraction, and then subjected the residual aqueous fraction to cation exchange, evaporation to dryness, and silylation. These two chemicals may have been retained, at least partially, on the cation-exchange cartridge before evaporation. 

Water-borne polyurethane coatings are formulated by incorporating ionic groups into the polymer backbone. These ionomers are dispersed in water through neutralization. The experimental 1,12-dodecane diisocyanate (C12DI Du Pont) is especially well suited for the formation of water-borne polyurethanes because of its hydrophobicity (39). Cationomers are formed from IPDI, A/ -methyl diethanolamine, and p oly (tetramethylene adipate diol)... 

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