Oil and gas production handbook An introduction to oil ... - ABB Group
Oil and gas production handbook An introduction to oil ... - ABB Group
Oil and gas production handbook An introduction to oil ... - ABB Group
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5.3.1 Acid <strong>gas</strong> removal<br />
Acid <strong>gas</strong>es such as carbon dioxide <strong>and</strong> hydrogen sulfide form acids when<br />
reacting with water, <strong>and</strong> must be removed <strong>to</strong> prevent corrosive damage <strong>to</strong><br />
equipment <strong>and</strong> pipelines. Hydrogen sulfide is also <strong>to</strong>xic <strong>and</strong> <strong>to</strong>tal sulfur<br />
content is normally regulated.<br />
The main removal process can be based on several principles:<br />
Absorption allows<br />
acidic <strong>gas</strong>es <strong>to</strong> be<br />
dissolved in a solvent,<br />
<strong>to</strong> be released by<br />
regeneration in a later<br />
stage.<br />
Amine<br />
absorption (as shown<br />
on the right) is the most<br />
common process for<br />
acid <strong>gas</strong> removal.<br />
Monoethanolamine<br />
(MEA) dominates for<br />
CO 2 removal. Solutions<br />
with inorganic solvents<br />
based on ammonia are<br />
under development. Ill:<br />
Wikipedia<br />
A typical amine <strong>gas</strong> treating process (as shown in the flow diagram) consists<br />
of an absorber unit, a regenera<strong>to</strong>r unit <strong>and</strong> accessory equipment. In the<br />
absorber, a "lean" amine solution absorbs H2S <strong>and</strong> CO2 from the upflowing<br />
sour <strong>gas</strong> <strong>to</strong> produce a sweetened <strong>gas</strong> stream as a product. The "rich" amine<br />
solution contains the absorbed acid <strong>gas</strong>es <strong>and</strong> is routed in<strong>to</strong> the regenera<strong>to</strong>r<br />
(a stripper with a reb<strong>oil</strong>er). The stripped overhead <strong>gas</strong> from the regenera<strong>to</strong>r<br />
is concentrated H 2 S <strong>and</strong> CO 2 .<br />
Adsorption relies on the molecules <strong>to</strong> bind <strong>to</strong> the surface of certain solids.<br />
After a certain time the material must be regenerated <strong>to</strong> release the <strong>gas</strong>.<br />
Principles used include pressure swing adsorption (PSA), temperature swing<br />
adsorption (TSA) <strong>and</strong> electric swing adsorption (ESA).<br />
Cryogenic removal uses a turbo exp<strong>and</strong>er: A <strong>gas</strong> turbine is driven by the<br />
exp<strong>and</strong>ing <strong>gas</strong> which then cools <strong>to</strong> below the dew point for the <strong>gas</strong> <strong>to</strong> be<br />
removed.<br />
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