(613a) Comparison of Amine-Based Absorbents for Post-Combustion Carbon Capture
AIChE Annual Meeting
2011
2011 Annual Meeting
Sustainable Engineering Forum
Sorbent Processes for Carbon Capture
Wednesday, October 19, 2011 - 3:15pm to 3:40pm
As
a part of this work, we have performed a comparison of 4 amine-based absorbents
using the process simulation software ProMax® with TSWEET®.
Absorbents were compared at pulverized coal fired power plant flue gas conditions.
The criteria for comparison of absorbents are the energy requirement and
absorber and stripper dimensions for 90% CO2 capture (separation +
compression) from a 500 MW pulverized coal fired power plant which are loosely
representative of the operating and capital cost respectively. Due to the large
flow-rate (~1100 MMSCFD) of flue gas that must be processed by the separation
system, use of 3 absorber/stripper trains is proposed. Separated CO2
is compressed to a pipeline pressure of 8MPa using a 4 stage compressor train.
The amine absorbents considered for comparison are monoethanolamine (MEA),
diethanolamine (DEA), diglycolamine (DGA) and 2-amino-2-methyl-1-propanol
(AMP). The parameters explored as a part of this study includes ? absorbent
concentration, lean absorbent entry temperature into the absorber column,
stripper pressure. On the basis of our findings, we report that diglycolamine
(DGA) and diethanolamine (DEA) are superior absorbents than monoethanolamine
(MEA) and 2-amino-2-methyl-1-propanol (AMP) for CO2 capture. A
higher stripper pressure reduces the overall energy requirement for CO2
capture by decreasing the stripping steam requirement as well as reducing the
compression costs. Figure 1 and Figure 2 are plots of change in stripper
diameter and overall energy duty for CO2 separation with change in
the stripper pressure.
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Figure
1: Stripper Diameter Vs. Stripper Pressure
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Figure
2: Energy Duty for CO2 separation Vs. Stripper Pressure