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In the present paper, the performance of an energy storage concept based on the integration of a compressed air energy storage (CAES) system into a gas-steam combined cycle (GSCC) plant is investigated. CAES systems featured by different design specifications have been coupled with a commercially available small size GSCC plant. Storage efficiencies up to 65% have been evaluated for CAES design power output ranging from 5 to 10 MW. A techno-economic analysis aimed at assessing plant performance and investment costs has been performed. Despite the relatively high investment costs and the storage efficiency being less than those featuring alternative storage approaches, the proposed system may be considered of interest due to the long-life duration and the established technologies available for the key plant components. [ABSTRACT FROM AUTHOR]

Recent installed power plants (PP) in Qatar and other Gulf Co-operation Countries (GCC) are using combined cycle (CC). The CC cycle consists of gas turbine (GT), heat recovery steam generators (HRSG), and steam turbine (ST). In these plants, GTs produce electric power (EP) and its exhaust hot gasses operate the HRSG to generate steam. The steam is supplied to ST that generates more EP, and its extracted (or discharged) steam is directed to thermally operated desalting plant (DP), e.g. multi stage flash (MSF) or multi-effect thermal vapor compression (ME-TVC) producing desalted seawater (DW). A plant producing both EP and DW is called co-generation power desalting plant (CPDP). The used ST type is either extraction condensing steam turbine or back-pressure steam turbine. The MSF or ME-TVC consumes about 280 MJ/m3thermal energy, besides pumping energy of 4 kWh/m3for MSF or 2 kWh/m3for ME-TVC systems. Because of high consumed energy, the MSF and ME-TVC systems have to be substituted by the much more energy-efficient seawater reverse osmosis (SWRO) desalting system, which consumes 4–5 kWh/m3only as pumping energy. Replacement of the MSF (or ME-TVC) with the SWRO system will ban the use of steam extracted (discharged) to the DP; the plants produce only EP, and become single-purpose PP. This reduces the plant overall efficiency unless major retrofitting is done by adding low pressure (LP) ST and condenser to expand the steam that was supplied to the DP in the turbine to produce more work. In this paper, it is suggested that the CPDP widely used in the GCC to become a tri-generation plant producing EP, DW (by SWRO), and chilled water for district cooling (DC). An analysis is presented for the newly suggested configuration. It showed that a reference plant can be fitted with SWRO to replace the DP of MSF or ME-TVC and gives almost the same DW production capacity for the identical consumed EP by the MSF units. The process heat that was supplied to the thermal desalting units would be utilized for DC system using an absorption cooling unit(s). Comparisons of absorption cooling with the EP driven mechanical vapor compression refrigeration; and SWRO with the MSF desalting systems are illustrated in this article. The benefits of using DC in the GCC are also presented. [ABSTRACT FROM PUBLISHER]

This paper presents an evaluation of the environmental performance of an advanced zero emission plant (AZEP) including CO2 capture. The evaluation is conducted with the aid of an advanced exergoenvironmental analysis. The results are compared with those of a reference combined-cycle power plant without CO2 capture. Advanced exergy-based methods are used to (a) quantify the potential for improving individual components or overall systems, and (b) reveal detailed interactions among components--two features not present in conventional analyses, but very useful, particularly when evaluating complex systems. In an advanced exergoenvironmental analysis, the environmental impacts calculated in a conventional exergoenvironmental analysis are split into avoidable/ unavoidable (to evaluate the potential for component improvement) and endogenous/exogenous (to understand the interactions among components) parts. As in the reference plant, the potential for reducing the environmental impact of the AZEP has been found to be limited by the relatively low avoidable environmental impact associated with the thermodynamic inefficiencies of several of its components. However, although the environmental impacts for the majority of the components of the plant are related mainly to internal inefficiencies and component interactions are of secondary importance, there are strong interactions between the reactor and some other components. [ABSTRACT FROM AUTHOR]

Abstract: This paper reports the results of an environmental impact assessment (EIA) of a hypothetical 400 MWe IGCC power plant fitted with CO2 capture technology and includes the transportation of CO2 via a high pressure pipeline to a geological formation under the North Sea and subsequent storage. The emphasis has been on assessing environmental impacts from those features which are specific to the Carbon Capture and Storage (CCS) technology and includes an appraisal of the current adequacy of information to enable EIAs for the power plant, transportation and storage components to be undertaken. [Copyright &y& Elsevier]