Alkanolamine solutions, application

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... 

The application of this model to alkanolamine solutions is not possible directly since the specific interaction parameters (B s) for alkanolammonium ions and carbamate ions are not available. Also the dissociation constant for the simplest amines (MEA, DEA,... 

A number of reviews are available discussing the application of membrane contactors for acid gas removal (Li and Chen, 2005 Mansourizadeh and Ismail, 2009) [4] [7]. Most research activities described in the literature deal with use of membrane contactor for the removal of carbon dioxide. Most of the time alkanolamine solutions have been used for the selective removal of CO2 from various gas streams (Jamal et al. 2006 Wang et al. 2004) [2] [10]. The effect of the amine solvent, the operating conditions, and the membrane characteristies on the removal of CO2 has been studied by (Wang et al, 2004) [10]. Results for the kinetics for both the absorption and desorption rate of CO2 for different amine absorption liquids (MEA, DEA, MDEA) and AMP and mixtures of these absorption liquids have been reported by (Jamal et al., 2006) [2]. Also, the use of other types of absorption liquids has been studied. Results for different amino acid salt solutions as CO2 absorbent have been described by (Lu et al., 2009) [6]. The use of membrane contactors is not limited to the removal of CO2. Membrane contactors have also been applied to remove H2S and SO2 from different gas streams (Li et al. 2000) [5]. 

Alkanolamines, generally referred to as amines, are organic compounds of the form Hn-N-(R0H)3-n (3) the hydroxyl group generally provides for the compounds solubility in water, while the HN group provides the alkalinity in water solutions to cause the absorption of acid gases. Amine processes used commercially are shown in Table I. These compounds are chemical solvents they combine chemically with H2S, C02, and other sulfur compounds. They are customarily regenerated by the application of heat. 

Water Hyacinth. Water hyacinth (Eichornia crassipes Solms) has been killed by 0.1% solution of the alkanolamine salt of 2,4-D in Indonesia (54), or in the Philippines by the isopropyl ester in as low as 0.1% solutions (39). In the southern United States, 2,4-D has been widely used to kill this plant. This plant is of relatively minor importance in Puerto Rico. It tends to choke up river mouths and is removed to improve drainage. A single application of the isopropyl ester of 2,4-D has given excellent results on a small scale. 

Derivatization After Desorption. Alkanolamines, highly polar basic compounds, present a difficult analytical problem. Although direct gas chromatographic separations can be achieved, this technique is not applicable to trace analysis due to sorption problems at trace concentrations. A derivatization/gas chromatographic procedure has been developed for the determination of alkanolamines in air as low as 100 ppb (54,55). The samples are collected on activated alumina and desorbed with an aqueous solution of 1-octanesulfonic acid. The... 

Alkanolamines are used in scrubbers to clean streams containing acid gases. Extension of existing applications to new situations involving carbon capture and sequestration of CO2 for environmental reasons will lead to increased demand for these substances. The reaction of ammonia (A) with ethylene oxide (EO) in aqueous solution produces monoethanolamine (MEA), diethanolamine (DEA), and triethanolamine (TEA). The reactions for stepwise formation of these products are... 

The authors of this paper have proposed the application of novel high performance membranes with the dense thin top-layer made of the glassy polymer PTMSP with the highest gas permeance among known polymers. It was already shown that PTMSP as a membrane material possesses long-term chemical and mechanical stability at typical MGD conditions - amine-based solvent, trans-membrane pressure up to 40 bar and temperature 100 °C [7]. Furthermore, PTMSP is a barrier material towards chemical solvents such as aqueous solutions of alkanolamines [7] and some physical solvents like water [8] and ionic liquid [9]. Details about the development of these membranes are described elsewhere [10], In this paper, the focus is on experimental work on using these membranes in contactors and the implications for application in natural gas processing. 

Alkanolamines are used as cross-linking and hardener accelerators in epoxy resins applications. Improved thermal and oxidative stability of polyvinyl alcohol, poly(phenylene ether), polystyrene, polypropylene, and polyethylene polymers are achieved by the addition of small amounts of the alkanolamines. Diethanolamine and morpholine act as initiators for the preparation of poly (alkyl methacrylate) in bulk or solution polymerization. The ethanolamines are efficient initiators for the preparation of polyvinyl chloride. Alkanolamines promote cross-linking of styrene copolymers with polystyrene or polyvinyl alcohol. Addition of alkanolamines to phenolic formaldehyde or urea formaldehyde resins affords improved electrical properties and increased water solubility. 

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