Triethanolamine solvent process

Some processes combine the use of chemical and physical solvents. An example is a dual solvent process based on the use of monoethanolamine and triethanolamine (MEA/TEA) [312-314]. In other cases the process is based on the use of a solvent which exhibits at the same time some of the properties attributed to both physical and chemical solvents. This is notably true for activated methyldiethanolamine, which is used in the MDEA process developed by BASF [311, 314-320, 905, 906]. This solvent, operating at an intermediate temperature, releases a significant part of the dissolved carbon dioxide by flashing, thus reducing the energy required for reboiling and thereby the overall energy consumption. 

Polymerization was generally carried out in a freezer at —20" C under a 350 nm UV source. Following polymerization, capillaries were rinsed with a solvent such as acetonitrile and electrolyte such as acetonitrile in a low pH buffer solution of 2M acetic acid/triethanolamine (pH 3.0 (80% acetonitrile to 20% buffer, v/v)) in order to wash out any remaining initiator, unreated monomers, and template molecules. This entire process is shown in Fig. 5. 

Aqueous alkanolamine solutions are frequently used for removal of acidic gases such as carbon dioxide and hydrogen sulfide from gas streams in the natural gas, synthetic, and refinery industries. Several options are available for removing acid gases, but by far the most popular is the absorption by amine based solvents such as monoethanolamine (MEA), diglycolamine (DGA), diethanolamine (DEA), di-isopropanolamine (DIPA), triethanolamine (TEA), N-methyldiethanolamine (MDEA), 2-amino-2-methyl-l-propanol (AMP), and 2-piperidineethanol (2-PE) in reversible absorption-regeneration processes [1]. 

Wik et al. [26] reported the reaction of a natural polyol derived from castor oil and polymeric 4,4 -diphenylmethane diisocyanate (pMDl) used to prepare solid materials reinforced with nanocellulose. The polyol was obtained by the reaction of castor oil with triethanolamine. The reaction between the castor oil-based polyol and the isocyanate started almost immediately after mixing these main components, even without the addition of a catalyst. This fact forced the use of an organic solvent to reduce the initial reaction rate, which was evaporated during the curing process. Nanocellulose obtained by acid hydrolysis of commercial microcrystalline cellulose was added to the polyol (0.5, 1, and 3 wt%) and dispersed by sonication. It was found that the addition... 

Park Y.I., Kim C.E., Lee H.W. Effects of catalyst and solvent on PbTiOa fibCTS prepared from triethanolamine complicated titanium isopropoxide. J. Sol-Gel Sd. Technol. 1999 14 149-162 Rabinovich E.M., Kopylov N.J. Rheological behavior oflow-snrface-area-particnlate silica sols in the presence of F ions. In Ultrastructure Processing of Advanced CCTamics, J.D. Mackenzie, D.R. Ulrich, eds New York John Wiley Sons, 1988, pp. 285-293 Sacks M.D., Sheu R.-S. Rheological properties of silica sol-gel materials. J. Non-Cryst. Solids 1987 92 383-396... 

The original Citro-Solv process was used at temperatures of about 200°F (93°C)for the iron stage and at about 150°F (66°C) for the copper stage. Recent improvements have included the use of ammonium bifluoride to speed the rate of iron oxide removal, and the use of higher temperatures, that is, up to 300°F (149°C). The increased temperatures require that the iron stage is conducted at a pH of 6.0, so that the inhibitors can adequately control the corrosion rate of the metal being cleaned. Additional variations include the use of triethanolamine (TEA—instead of ammonia) for primary pH control. This variation improves the safety of the solvent used (TEA is less toxic than ammonia), and it also reduces the cracking incidents of copper-base metals in mixed metal systems (ferrous and copper). 

We recently reported the discovery of a general, low cost route to alkoxide precursors to aluminosilicates (spinel, mullite and cordierite), by direct reaction of any stoichiometric mixture of Si02, A1(0H)3 and group I/II metal hydroxides with triethanolamine (TEA) in ethylene glycol (EG) solvent (77). This process, termed the oxide one pot synthesis (OOPS) process provides stable, processable precursors to phase pure ceramic materials. A general reaction for the synthesis of OOPS derived precursors is given by ... 

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