Amine Guard

Amine antioxidants Amine boranes Amine Guard... 

Primary alkanolamine solutions require a relatively high heat of regeneration. Also excessive temperatures or localized overheating in reboilers cause the MEA to decompose and form corrosive compounds. An inhibitor system, such as the Amine Guard system developed by Union Carbide, is an effective method of corrosion control (52). Inhibitors permit the use of higher (25—35%) concentration MEA solutions, thus allowing lower circulation rates and subsequendy lower regeneration duty. 

Union Carbide has developed Amine Guard, which essentially eliminates corrosion in amine systems (32—35). It permits the use of substantially higher amine concentrations and greater carbon dioxide pick-up rates without corrosive attack. This results in an energy requirement comparable to that of the carbonate process and allows the use of smaller equipment for a specific C02-removal appHcation thereby reducing the capital cost. 

The process is capable of achieving higher solubiHties of CO2 in the solution without the corrosion problems encountered with amine systems before the advent of Amine Guard. The Sulfinol process is used in over 50 plants worldwide nevertheless, it is used less often than the amine or carbonate processes. 

Amine Guard A process for extracting acid gases from refinery streams by scrubbing with an alkanolamine. Many such processes have been developed, this one was developed by the Union Carbide Corp. and uses monoethanolamine. It has been used to purify hydrogen produced by steam reforming. In 1990, over 375 units were operating. 

Amine Guard, 4 813 Amine hydrates, 14 171 Amine oxides, 2 463-476 as cellulose solvents, 11 266 chemical reactions, 2 466-469 commercial, 2 464t economic aspects, 2 471 health and safety factors, 2 472 manufacturing and porcessing, 2 469-471... 

The Amine Guard is a corrosion inhibitor that was developed by Union Carbide. It is added to the MEA solvent and has the further advantage that MEA concentration can be increased. The higher MEA concentration leads to a lower circulation flow rate and a lower energy demand during regeneration74. 

A corrosion inhibitor is used with this process. With the Amine Guard inhibitor, the MEA concentration in the circulating solution can be increased to 30% from a normal 20%. Hence, the circulating rate can be decreased by 33% and the heat requirements are decreased by 43%. 

Two examples of this technology are the Amine Guard FS Process and the Amine Guard II Process. A comparison of the two processes is given in Table 5.35200. 

The Amine Guard FS flowsheet is shown in Figure 5.40, and the Amine Guard II flowsheet is shown in Figure 5.41. Both of these technologies are available from UOP200... 

Table 5.35. Comnarison of Amine Guard FS and Amine Guard II Processes200...

Amine Guard Systems in Hydrogen Production, AIChE, 8601 National Meeting, Houston, TX, Apr. 1-5, 1979. 

CO conversion is achieved in the HT and LT shift over standard catalyst, while C02 is removed either in the BASF-aMDEA, the UOP-Benfield or the UOP-Amine Guard process. Remaining carbonoxides are reconverted to methane in catalytic methanation to trace ppm levels. 

A number of different acid gas removal processes have been used for removal of COj from synthesis gas. They include MEA with UCAR Amine Guard, Selexol, Rectisol, Sulfinol and hot potassium carbonate. The flow scheme depicted in Figure 3 shows an amine-based CO2 removal system. 

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