Novel process designs to improve the efficiency of postcombustion carbon dioxide capture

Abstract

The term carbon dioxide capture and storage (CCS) refers to a range of technologies that can reduce CO2 emissions from fossil fuels enabling the continued use of this fuel type without compromising the security of electricity supply. The technologies applicable to CCS differ in many key aspects; the stage of the electricity generation process at which the CO2 is captured, the CO2 capture process, efficiency, availability and matureness of the technology. The integration of these technologies into power plants results in a reduction in power generation efficiency, which remains one of the major issues for the commercial implementation of CCS. Among the possible technologies, the focus of this thesis is on post-combustion capture as it is a known technology, is readily available and it can be retrofitted to existing power plants. This thesis is concerned with the development of new carbon capture processes that require less energy for CO2 separation and are, at the same time, more environmentally friendly. Prior to the development of any new process, the current state of the art needs to be analysed and updated in order to set realistic targets for the new technology and benchmark the potential of the newly developed processes. Therefore, part of the work of this thesis is a thorough benchmarking exercise in which updated baselines for the performance of conventional post-combustion capture processes are given. The new process concepts developed in this thesis are based on the combination of enhanced absorption and enhanced desorption, two effects encountered in capture processes that are based on precipitating amino acid solvents. For this purpose, the conceptual design methodology has been followed with a specific target of energy reduction set to (at least) 30% of a conventional MEA process.