Power generation plants with carbon capture and storage: A techno-economic comparison between coal combustion and gasification technologies

Highlights: • Techno-economic performance of coal-fired power plants (without and with CCS). • Without CCS system, USC is more efficient and cost-competitive than IGCC. • CCS energy penalties are more relevant for USC than IGCC. • Higher SNOX system costs are partially compensated by better USC performance. • CCS technologies cannot be profitable without adequate policies and incentives. - Abstract: Worldwide energy production requirements could not be fully satisfied by nuclear and renewables sources. Therefore a sustainable use of fossil fuels (coal in particular) will be required for several decades. In this scenario, carbon capture and storage (CCS) represents a key solution to control the global warming reducing carbon dioxide emissions. The integration between CCS technologies and power generation plants currently needs a demonstration at commercial scale to reduce both technological risks and high capital and operating cost. This paper compares, from the technical and economic points of view, the performance of three coal-fired power generation technologies: (i) ultra-supercritical (USC) plant equipped with a conventional flue gas treatment (CGT) process, (ii) USC plant equipped with SNOX technology for a combined removal of sulphur and nitrogen oxides and (iii) integrated gasification combined cycle (IGCC) plant based on a slurry-feed entrained-flow gasifier. Each technology was analysed in its configurations without and with CO2 capture, referring to a commercial-scale of 1000 MWth. Technical assessment was carried out by using simulation models implemented through Aspen Plus and Gate-Cycle tools, whereas economic assessment was performed through a properly developed simulation model. USC equipped with CGT systems shows an overall efficiency (43.7%) comparable to IGCC (43.9%), whereas introduction of SNOX technology increases USC efficiency up to 44.8%. Being the CCS energy penalties significantly higher for USC (about 10.5% points vs. about 8.5 for IGCC), the IGCC with CCS is more efficient (35.3%) than the corresponding CO2-free USC (34.2% for the SNOX-based configuration). Whereas, for the case study, USC is most profitable than IGCC (with a net present value, NPV, of 190 M€ vs. 54 M€) for a conventional configuration, CO2-free IGCC shows a higher NPV (−673 M€) than USC (−711 M€). In any cases, the NPV of all the CO2-free configurations is strongly negative: this means that, with the current market conditions, the introduction of a CCS system cannot be economically justified without a significant incentive