ie6b00318_si_001.pdf (146.66 kB)
Regulatory Control of Amine Scrubbing for CO2 Capture from Power Plants
journal contribution
posted on 2016-04-05, 00:00 authored by Matthew
S. Walters, Thomas F. Edgar, Gary T. RochelleTight integration
between the amine scrubbing plant, coal-fired
power plant, and enhanced oil recovery (EOR) facility creates process
design and control challenges for post-combustion CO2 capture.
A dynamic model of an advanced amine scrubbing process and a steady
state model of a 550 MWe power plant were used to examine four bounding
cases that represent different system components dominating the regulatory
process control strategy. Satisfying the operational and economic
objectives of one system component resulted in unfavorable dynamic
performance for the remainder of the system. When a step change decrease
occurred in either the CO2 delivery rate from the capture
plant to the EOR facility or the steam extraction rate from the power
plant to the capture plant, more than 3 h was required for the amine
plant to reach a new steady state. Attempting to control the CO2 removal rate from the flue gas can not be satisfactorily
achieved through regulatory control alone. Controlling stripper temperature
and pressure brought all manipulated variables to within 5% of their
final steady state value in less than 2 h in response to a decrease
in power plant load. The design of process equipment, specifically
the CO2 stripper and steam extraction valve, depends heavily
on the desired process control strategy. The solvent surge tank should
be placed in the flow of the rich solvent to allow for tighter control
of absorber removal, although the difference in system performance
between rich and lean surge tanks was found to be negligible when
the surge tank inventory was small.