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

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 1000MWth. 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 190M€ vs. 54M€) for a conventional configuration, CO2-free IGCC shows a higher NPV (−673M€) than USC (−711M€). 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.