8 research outputs found
Solvent analysis instrumentation options for the control and flexible operation of post combustion carbon dioxide capture plants
Dispatchable low carbon electricity has been identified as a key requirement for low
carbon electricity systems because these systems must provide reliable electricity services to
an increasing portion of the world’s population while utilising an increasing share of nondispatchable
assets such as renewable and nuclear generators. Fossil fuel generators can
provide dispatchable low carbon electricity by leveraging post-combustion carbon capture
technologies assuming post-combustion capture (PCC) plants can operate in a flexible and
efficient manner. This thesis explores the connection between solvent analysis techniques
and the optimal operation of PCC plants with a particular focus on process optimisation and
control under flexible and transient conditions.
The connection between solvent analysis measurements and PCC plant process control
and optimisation strategies is established. An ideal set of analysis technique criteria is
established for flexible post-combustion capture plants. Currently available solvent analysis
techniques are surveyed and evaluated against the ideal set of criteria. Specific weaknesses
of current techniques are highlighted and two novel solvent analysis techniques are
introduced to address these weaknesses.
The first provides continuous amine concentration and CO2 loading measurements at
process flow conditions by inferring solvent chemical composition from physical properties.
This method was evaluated by deploying an instrument prototype to a post-combustion pilot
plant to continuously analyse solvent during a test campaign which simulated flexible plant
operation. The measurement results were compared against industry standard solvent
analysis techniques and the inferential technique was found to produce sufficient
measurement accuracy and sensitivity while providing a faster, lower cost and more robust
measurement technique. The second technique combines the strengths of several currently
available CO2 loading techniques to measure CO2 gas evolved from an acidified solvent
under vacuum conditions. The technique was found to provide superior measurement
accuracy and sensitivity compared to currently available methods when measuring lab
standard solutions.
The integration of these novel analysis techniques into advanced process control
systems is proposed and future method improvements are suggested