Chemical Solvents
Proprietary Carbonate Systems
Several proprietary processes have been developed based on the hot carbonate system with an activator or catalyst. These activators increase the performance of the hot PC system by increasing the reaction rates both in the absorber and the stripper. In general, these processes also decrease corrosion in the system. The following are some of the [...]
18Sep2009 | admin | Comments Off | ContinuedHot Potassium Carbonate Process
The hot potassium carbonate (K2CO3) process uses hot potassium carbonate to remove both CO2 and H2S. It works best on a gas with CO2 partial pressures in the range of 30-90 psi. The main reactions involved in this process are:
It can be seen from Equation 7-12 that H2S alone cannot be removed unless there is [...]
18Sep2009 | admin | Comments Off | ContinuedDiisopropanolamine Systems
Diisopropanolamine (DIPA) is a secondary
amine used in the Shell ADIP® process to sweeten natural gas. DIPA systems are similar to MEA systems but offer the following advantages: carbonyl sulfide (COS) can be removed and regenerated easily and the system is generally noncorrosive and requires less heat input.
One feature of this process is that at low [...]
Diglycolamine Systems
The Fluor Econamine® process uses diglycolamine (DGA) to sweeten natural gas. The active DGA reagent is 2-(2-amino-ethoxy) ethanol, which is a primary amine. The reactions of DGA with acid gases are the same as for MEA. Degradation products from reactions with COS and CS2 can be regenerated in a reclaimer.
DGA systems typically circulate a solution [...]
Diethanolamine Systems
Diethanolamine (DBA) is a secondary arnine that has in recent years replaced MEA as the most common chemical solvent. As a secondary amine, DEA is a weaker base than MEA, and therefore DEA systems do not typically suffer the same corrosion problems, In addition, DEA has lower vapor loss, requires less heat for regeneration per [...]
18Sep2009 | admin | Comments Off | ContinuedMonoethanolamine Systems
Monoethanolarnine (MBA) is a primary amine that can meet nominal pipeline specifications for removing both H2S and CO2. MBA is a stable compound and in the absence of other chemicals suffers no degradation or decomposition at temperatures up to its normal boiling point. ME A reacts with CO2 and H2S as follows:
These reactions are reversible [...]
18Sep2009 | admin | Comments Off | ContinuedAmine Processes
Several processes are available that use the basic action of various amines. These amines can be categorized as primary, secondary, or tertiary according to the number of organic groups bonded to the central nitrogen atom.
Primary amines are stronger bases than secondary amines, which are stronger than tertiary amines. Amines with stronger base properties will be [...]