Capture

 

Inputs for the MEA-based absorber and regenerator in hydrogen production plants are entered on the Capture parameter screen. The following parameters are available:

•Solvent Concentration: The solvent used for CO2 absorption is a mixture of monoethanolamine (MEA) and water. MEA is a highly corrosive liquid, especially in the presence of oxygen and carbon dioxide, and hence needs to be diluted. Today, the commercially available MEA-based technology supplied by Fluor Daniel uses 30% w/w MEA solvent with the help of some corrosion inhibitors. This parameter is read-only and is shown for reference.

•Lean CO2 Loading: Ideally, the solvent will be completely regenerated on application of heat in the regenerator section. Actually, even when applying heat, not all the MEA molecules are freed from CO2. So, the regenerated (or lean) solvent contains some "left-over" CO2. The level of lean solvent CO2 loading mainly depends upon the initial CO2 loading in the solvent and the amount of regeneration heat supplied, or alternatively, the regeneration heat requirement depends on the allowable level of lean sorbent loading. This parameter is read-only and is shown for reference.

•Solvent Losses (exclud. acid gasses): MEA is a reactive solvent. In spite of dilution with water and the use of inhibitors, a small quantity of MEA is lost through various unwanted reactions, mainly the polymerization reaction (to form long-chained compounds) and the oxidation reaction, forming organic acids and liberating ammonia. It is assumed that 50% of this MEA loss is due to polymerization, and the remaining 50% of the MEA loss is due to oxidation to acids. This parameter is read-only and is shown for reference.

•Solvent Recovered: This is the amount of solvent regenerated by the caustic added to the reclaimer. This parameter is read-only and is shown for reference.

•Number of Absorber Intercoolers: This is the number of absorber intercoolers used, currently always one. This parameter is read-only and is shown for reference.

•Absorber Intercooling Duty: The amount of heat removed by the intercooler installed between absorber stages. An absorber intercooler lowers the absorber temperature, thereby enhancing the absorption rate.

•Liquid-to-Gas Ratio: The liquid-to-gas ratio is the ratio of the total molar flow rate of the liquid (MEA sorbent plus water) to the total molar flow rate of the flue gas being treated in the absorber.

•Absorber & Wash Column Pressure Drop: This is the pressure drop that the flue gas has to overcome as it passes through a very tall absorber column, countercurrent to the sorbent flow.

•ID Fan Isentropic Efficiency: This parameter compares the actual work done by the ID fan on the captured flue gas to the ideal, frictionless work required to achieve the same outlet pressure.

•ID Fan Mechanical Efficiency: This parameter accounts for physical friction losses in the blower, such as losses in mechanical seals, bearing, and gears.

•ID Fan Discharge Pressure: This is the outlet pressure of the ID fan blower on flue gas before it enters the absorber.

•Activated Carbon Used: This is the amount of activated carbon in the sorbent circuit to help remove the polymeric sorbent compounds.

Additional capture options are available on the following screen, Capture cont.

Copyright © 2022-2026 University of Wyoming. All rights reserved. Visit us at https://www.iecm-online.com/