Flexible operation of CSIRO's post-combustion CO2 capture pilot plant at the AGL Loy Yang power station

Abstract

Flexible operation has the potential to significantly improve the economic viability of post-combustion CO2 capture (PCC). However, the impact of disturbances from flexible operation of the PCC process is unclear.The purpose of this study was to investigate the effects of flexible operation in a PCC pilot plant by implementing step-changes for improved dynamic data reliability. The flexible operation campaign was conducted at the CSIRO PCC pilot plant at AGL Loy Yang using monoethanolamine (MEA) absorbent. The pilot plant was operated under a broad range of transient conditions (changing flue gas flow, liquid absorbent flow and steam pressure) to capture the dynamics of a PCC process during flexible operation. The study demonstrated that the dynamics of flue gas flow rate was faster than absorbent flow rate. The greatest CO2 removal % was achieved at the lowest flue gas flow rate or at the highest absorbent flow rate; however the latter provided improved energy efficiency. The steam pressure parameter could adjust the temperature of all columns simultaneously which can be used to compensate for effects from ambient conditions or heat losses. These results verify the technical feasibility of flexible PCC operation and provide a suitable dataset for dynamic model validation.

Dynamic Process Model Validation and Control of the Amine Plant at CO2 Technology Centre Mongstad

“…This confirms the buffering effect by the chemical process in terms of the response of CO 2 desorbed when the flue gas volumetric flow rate is changed. There is evidence to support this observation in previous pilot plant studies [46][47][48]. The delay in the response is partly attributed to solvent circulation time and the redistribution of liquid.…”

“…They concluded that the overall system acts as a buffer to perturbations at the plant inlet and that the coupled operation of the absorber/desorber unit led to fluctuations in the system when all parameters-flue gas and solvent mass flow rates and reboiler duty-are changed simultaneously. Bui et al [47] presented a flexible operation campaign conducted at the Commonwealth Scientific and Industrial Research Organization (CSIRO)'s PCC pilot plant in Australian Gas Light Company (AGL) Loy Yang, a brown-coal-fired power station in Australia. The generated transient data included step changes in flue gas flow rate, solvent flow rate and steam pressure.…”

Reinforced coordinated control of coal-fired power plant retrofitted with solvent based CO2 capture using model predictive controls

“…Instead of complex analytical model, data-driven models were developed through identification to investigate the characteristics of the PCC process in [20] and [21]. Dynamic performance of PCC unit were studied in [22] and [23] via open-loop step response tests on pilot plants, where the slow dynamic feature of the PCC process was clearly demonstrated.…”

Controllability and flexibility analysis of CO 2 post-combustion capture using piperazine and MEA

“…In summary, the implemented model and its numerical implementation enables transient simulation of a pilot-scale post-combustion capture plant and is adequate for dynamic control strategies development. As shown by Bui et al (2016), comparison to large scale plant-data covering a wide range of operating conditions is needed to ensure general dynamic validity of the model. It is especially important to compare the model to experiments coming from industrial-scale applications since postcombustion capture reached industrial deployment-stage.…”

“…In addition, differences in the physical properties of amines influence the mass transfer and hydraulic characteristics and therefore the dynamic behaviour of a capture plant. For example Bui et al (2016) reported that as MEA degrades, significant changes occur in their physical properties, e.g. viscosity which lead to poor liquid distribution.…”