Towards Zero Emissions from Fossil Fuel Power Stations

Abstract

It is projected that net zero carbon emissions are required early in the second half of this century to maintain global temperature increase to below 2 °C. To achieve this, the CO2 capture rates in CO2 Capture and Storage (CCS) chains would need to be higher than most current design values, ranging from 85% to 90%. In this study, results from previous studies were assessed to explore the potential to increase CO2 capture rates across the range of capture routes for power stations including post-/pre-combustion capture and oxyfuel. Next, using the most advanced technology for CO2-capture from power stations, i.e. liquid absorbent based post-combustion CO2-capture, the techno-economic performance of a capture process at higher capture rates (>90%) has been assessed. The work has focused on an initial standard design using a 30 wt% Monoethanolamine (MEA) solution and investigated the impact of increasing capture rates on the technical performance, in particular the specific reboiler duty. It was then extended to a number of cases studies, also allowing for process design modifications that aimed to minimise reboiler duty. The overall results are compared to the standard design in terms of process performance, capital costs and operational costs.Additionally, the use of biomass in combination with CCS by co-combustion was incorporated and the impact of fuel prices was assessed.