Efficiency evaluation procedure of coal-fired power plants with CO2 capture, cogeneration and hybridization

Abstract

In an energy landscape undergoing great change with regard to CO2 emissions, the evaluation of solutions allowing a drastic reduction of the anthropogenic emissions are carried out for more than a decade. Among them, CO2 capture and storage on coal power plants has been identified as a particularly promising solution but other options such as heat and electricity cogeneration and power plant hybridization with solar of biomass can also reduce the carbon footprint of electricity production. However, the implementation of an external process on a power plant impacts its electric production. Post- and oxy-combustion CO2 capture, cogeneration for industries or districts, or hybridization are all examples of processes either demanding thermal and electrical energy or providing heat valorization opportunities. To identify the true potential of those systems, the evaluation of the performance of the integrated system is necessary. Also, to compare different solutions, a common framework has to be adopted since the performance of those systems are often highly dependent of the considered hypotheses.This paper presents a full integration procedure suited for both new built and retrofit coal-fired power plants by means of easy-to-use correlations, which links heat demand to production loss and waste heat availability to production increase, taking their exergy content into account. This correlative approach provides an analytical tool allowing a quick and realistic evaluation of a given concept or process layout, without the need of a detailed full power plant model. Examples are given for CO2 capture, cogeneration and hybridization, illustrating the interest of the approach to evaluate and compare several technologies on a consistent manner. An Excel spreadsheet with the calculation procedure is available online (see supporting information).