Diisopropanolamine solutions

Simultaneous Mass Transfer of Hydrogen Sulfide and Carbon Dioxide with Complex Chemical Reaction in an Aqueous Diisopropanolamine Solution... 

Diethanolamine, diisopropanolamine, and isopropan olamine mixtures are less irritating to the skin than MEA and MIPA however, any one of them may produce severe skin irritation, even mild bums, if contact is prolonged or frequently repeated. Occasional short contact should not result in more than slight irritation. Undiluted triethanolamine and triisopropan olamine are slightly to moderately irritating to the skin. A bum may result from prolonged and repeated contact. Short occasional contact and solutions of less than 10% concentration are unlikely to cause more than very slight irritation, if any. 

Licensed by Shell the Sulfinol process combines the properties of a physical and a chemical solvent. The Sulfinol solution consists of a mixture of sulfolane (tetrahydrothiophene 1-1 dioxide), which is a physical solvent, diisopropanolamine (DIPA), and water. DIPA is a chemical solvent that was discussed under the amines. 

Sulfinol-X Shell Global Solutions Diisopropanolamine/MDEA + sulfolane + accelerator... 

Application to Alkanolamine Solutions Aqueous alkanolamine solutions are widely used for the removal of H2S and C02 from gaseous streams, because they can reduce the concentration of H2S and C02 to low levels, even if the gas stream is at a low total pressure. The most commonly used alkanolamines are monethanolamine (MEA) and diethanolamine. However, diisopropanolamine... 

In the SCOT process, the sulfur compounds in the Claus tail gas are converted to hydrogen sulfide by heating and passing it through a cobalt-molybdenum catalyst with the addition of a reducing gas. The gas is then cooled and contacted with a solution of diisopropanolamine (DIPA) that removes all but trace amounts of hydrogen sulfide. The sulfide-rich diisopropanolamine is sent to a stripper, where hydrogen sulfide gas is removed and sent to the Claus plant. The diisopropanolamine is returned to the absorption column. 

Solvents used for hydrogen sulfide absorption include aqueous solutions of ethanolamine (monoethanolamine, MEA), diethanolamine (DEA), and diisopropanolamine (DIPA) among others ... 

The simultaneous absorption of H2S and CO2 into aqueous 2.0 H diisopropanolamine (DIPA) solutions is studied both experimentally and theoretically. 

Combinations of physical and chemical absorption are also used, as in Shell s Sulfinol process in which a mixture of diisopropanolamine and sulfolane in water is utilized. For the hydrogen sulfide-free gases from the steam-reforming process, chemical scrubbing with activated potassium carbonate solutions or alkanolamines is preferred. In the case of hydrogen sulfide-containing gases from the partial oxidation process, physical absorption alone or in combination with chemical absorption is preferred. 

A minor variant to the amine scrubbing process described above is the Sulfinol process, which still uses an alkanolamine base, diisopropanolamine (35%), but in a solvent consisting of a mixture of sulfolane (40%), tetramethy-lene sulfone (CH2)4S02, a good hydrogen sulfide solvent) and water [29]. Other processes are based on hydrogen sulfide absorption in aqueous alkaline carbonate solutions, such as the Catacarb and Benfield systems (Eqs. 9.16 and 9.17). 

DIISOPROPANOLAMINE (110-97-4) Combustible liquid (flash point 260°F/127°C oc). Incompatible with oxidizers, strong acids, organic anhydrides, acrylates, alcohols, aldehydes, alkylene oxides, substituted allyls, cellulose nitrate, cresols, caprolactam solution, epichlorohydrin, ethylene dichloride, isocyanates, ketones, glycols, nitrates, phenols, vinyl acetate. Exothermic decomposition with maleic anhydride. Increases the explosive sensitivity of nitromethane. Attacks some paints, rubber, and coatings aluminum, copper, zinc, and their alloys. 

This case is similar to that of reaction 1 absorption of A followed by reaction with B in the liquid phase, with the difference that there are now two gases Ai and A2. Typical industrial examples are the reactions of CO2 and H2S with aqueous solutions of diglycolamine and diisopropanolamine, and of isobutylene and butenes with aqueous sulfuric acid. 

Water-soluble hyperbranched PEAs are nowadays developed for different applications such as paper coatings, kinetic hydrate inhibitors (KHIs) for the oil and gas industry, and biology and medicine devices. The last apphcations require a lower critical solution temperature (LCST) around physiological conditions, whereas high LCST values may be useful as KHIs. KeUand [50] has recently demonstrated that PEAs based on a cychc anhydride and diisopropanolamine can be effectively tuned by varying the hydrophobicity of the cyclic anhydride or by the addition of a less hydrophilic secondary amine (i.e., without hydroxyl groups). 

As coabsorption of CO2 leads to an increase in the size of the combined Claus and Scot system, it might be desirable to remove H2S as selectively as possible. Selective amine solutions are therefore used, normally diisopropanolamine (Dipa), or methyl-diethanolamine(MDEA) if CD2 contents are very high. 

The simultaneous absorption of two gases that react with the solvent at different rates has been studied by Ouwerkerk. The specific system which he selected for analysis was the selective absorption of HjS in the presence of CO2 into amine solutions. This operation is a feature of several commercially important gas purification processes. Bench scale experiments were conducted to collect the necessary pi sico-chemical data. An absorption rate equation was developed for H2S based on the assumption of instantaneous reaction. For CO2 it was found that the rate of absorption into diisopropanolamine (DIPA) solution at low CO2 partial pressures can best be correlated on the l is of a fast pseudo-first-order reaction. A computer program was developed which took into account the competition between H2S and CC>2 when absorbed simultaneously, and the computer predictions were verified by experiments in a pilot scale absorber. Finally, the methodology was employed successfully to design a large commercial plant absorber. 

VLB data on DIPA solutions with CO2 and H2S are given by Isaacs et al. (1977A and B). Ihe first of these references provides data on the acid gases ind endently and is the basis for Figure 2-41, which shows the partial pressure of the acid gases versus mole ratio in the liquid for 2.S M diisopropanolamine at 40°C and 100°C. Figures 2-42 and 2-43, which are fiom Isaacs et al. (1977B), show the effects of one acid gas on the other in 2.5N DPA at 40°C. 

ADIP [Possibly an acronym of DIPA, diisopropanolamine] A process for removing hydrogen sulfide, mer-captans, carbonyl sulfide, and carbon dioxide from refinery streams by extraction into an aqueous solution of diisopropanolamine or methyl diethanolamine. Developed by Shell and licensed by Shell Global Solutions International BV. More than 400 units were operating in 2000. 

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