Mathieu Lucquiaud

Flexible Operation of Coal Fired Power Plants with Postcombustion Capture of Carbon Dioxide

Carbon capture and storage is one family of technologies that could be used to significantly reduce global carbon dioxide (C O2 ) emissions. This paper reviews the likely flexibility of power plants with postcombustion capture, with a focus on an improved characterization of the dynamic performance of power plants with C O2 capture. The literature has focused on design and optimization for steady state operation of power plants with capture, often at a single design point. When dynamic behavior is considered, it is possible that designs should be altered for best overall plant performance. Economic trade-offs between improving transport and storage scheme flexibility and constraining power plant operations should also be carefully analyzed, particularly if the captured C O2 is to be used in another process such as enhanced oil recovery. Another important aspect of real plant operation will be adhering to legislative requirements. Further work is required to identify mechanisms that allow flexible operatio...

Retrofitting CO2 capture ready fossil plants with post-combustion capture. Part 1: Requirements for supercritical pulverized coal plants using solvent-based flue gas scrubbing:

Abstract Rapid global deployment of carbon capture and storage (CCS) requires a two-track approach. CCS needs to be deployed at scale as quickly as possible and other plants, if built without CCS, need to be built CO2 capture ready (CCR) before they are retrofitted. In particular, coal plants are likely to continue to be built in large numbers in developing countries. CCS is not an immediate option for all or most of these plants, but it would be feasible to make large numbers of them CCR for subsequent retrofit of flue gas scrubbing systems for post-combustion capture. This article will examine options for CCR steam turbines for such plants, showing that effective thermodynamic integration with the capture equipment can be achieved for minimal additional cost. The performance will be compared with the retrofit of non-CCR steam turbine configurations. Finally, the uncertainty of CCS development will be discussed and the performance of the CCR steam turbine options proposed will be assessed for a range of future possible CO2 scrubbing solvents that are less energy intensive than the original design case using current solvents.

CO2 capture-ready ultra-supercritical coal power plants

Abstract: Decarbonisation of fossil electricity generation is unlikely to be achieved without carbon capture and storage (CCS). In a period where fast learning-curves for carbon dioxide (CO2) capture technologies can be expected it is important that fossil plants built as CO2 capture-ready (CCR) are able to incorporate technology developments that occur during the period of time when the plant operates without capture. This chapter introduces strategies to design ultra-supercritical coal plants as CCR and follow the general principles of low additional capital cost, no upfront performance penalty, good performance with capture throughout a plant operating life and the ability to operate with the capture unit by-passed.

Retrofitting CO2 capture-ready fossil plants with post-combustion capture: Part 2 – Requirements for natural gas combined cycle plants using solvent-based flue gas scrubbing

Abstract A number of natural gas combined cycle (NGCC) power stations recently permitted in the UK have been required to be CO2 capture ready so that carbon capture and storage can be retrofitted once it is commercially viable (or legally required). Several options for future CO2 capture from NGCC units can be envisaged including post-combustion capture technology using flue gas scrubbing with aqueous solvents. When an NGCC plant is designed to be ready for a retrofit with post-combustion capture, one of the most important technical considerations is the steam extraction pressure and flow to provide the energy necessary for solvent regeneration. This is determined by the choice of solvent used, but new solvents are being developed and the exact future requirements, in perhaps 10–20 years time, cannot be predicted. Ways in which designs for the steam cycle of NGCC plants can cope with this challenge are presented. Several alternatives to mitigate the loss of power output of NGCC plants retrofitted with post-combustion capture and to achieve improved plant flexibility are also assessed and compared.

Linear and nonlinear instability in vertical counter-current laminar gas-liquid flows

We consider the genesis and dynamics of interfacial instability in vertical gas-liquid flows, using as a model the two-dimensional channel flow of a thin falling film sheared by counter-current gas. The methodology is linear stability theory (Orr-Sommerfeld analysis) together with direct numerical simulation of the two-phase flow in the case of nonlinear disturbances. We investigate the influence of two main flow parameters on the interfacial dynamics, namely the film thickness and pressure drop applied to drive the gas stream. To make contact with existing studies in the literature, the effect of various density contrasts is also examined. Energy budget analyses based on the Orr-Sommerfeld theory reveal various coexisting unstable modes (interfacial, shear, internal) in the case of high density contrasts, which results in mode coalescence and mode competition, but only one dynamically relevant unstable interfacial mode for low density contrast. A study of absolute and convective instability for low densi...

Retrofitting CO2 Capture to Existing Power Plants as a Fast Track Mitigation Strategy

Carbon capture and storage (CCS) is often identified as an important technology for mitigating global carbon dioxide (CO2 ) emissions. For example, the IEA currently suggests that 160GW of CCS may need to be installed globally by 2030 as part of action to limit greenhouse gas concentrations to 550ppm-CO2 eq, with a further 190GW CCS capacity required if a 450ppm-CO2 eq target is to be achieved. Since global rollout of proven CCS technologies is not expected to commence until 2020 at the earliest this represents a very challenging build rate. In these circumstances retrofitting CO2 capture to existing plants, probably particularly post-combustion capture on pulverized coal-fired plants, could play an important role in the deployment of CCS as a global strategy for implementing CO2 emissions reductions. Retrofitting obviously reduces the construction activity required for CCS deployment, since fewer additional new power plants are required. Retrofitting CCS to an existing fleet is also an effective way to significantly reduce CO2 emissions from this sector of the electricity generation mix; it is obviously not possible to effect an absolute reduction in coal power sector CO2 emissions simply by adding new plants with CCS to the existing fleet. Although it has been proposed that plants constructed now and in the future can be ‘capture ready’, much of the existing fleet will not have been designed to be suitable for retrofit of CO2 capture. Some particular challenges that may be faced by utilities and investors considering a retrofit project are discussed. Since it is expected that post-combustion capture retrofits to pulverized coal plants will be the most widely applied option for retrofit to the existing fleet (probably regardless of whether base plants were designed to be capture ready or not), a review of the technical and potential economic performance of this option is presented. Power cycle performance penalties when capture is retrofitted need to be addressed, but satisfactory options appear to exist. It also seems likely that the economic performance of post-combustion capture retrofit could be competitive when compared to other options requiring more significant capital expenditure. Further work is, however, required both to develop a generally accepted methodology for assessing retrofit economics (including consideration of the implications of lost output after retrofit under different electricity selling price assumptions) and to apply general technical principles to case studies where site-specific constraints are considered in detail. The overall conclusion from the screening-level analysis reported in this paper is that, depending on project-specific and market-specific conditions, retrofit could be an attractive option, especially for fast track initial demonstration and deployment of CCS. Any unnecessary regulatory or funding barriers to retrofit of existing plants and to their effective operation with CCS should, therefore, be avoided.Copyright