Effect of supplementary firing options on cycle performance and CO₂emissions of an IGCC power generation system

Abstract

SUMMARYSupplementary firing is adopted in combined-cycle power plants to reheat low-temperature gas turbine exhaust before entering into the heat recovery steam generator. In an effort to identify suitable supplementary firing options in an integrated gasification combined-cycle (IGCC) power plant configuration, so as to use coal effectively, the performance is compared for three different supplementary firing options. The comparison identifies the better of the supplementary firing options based on higher efficiency and work output per unit mass of coal and lower CO 2 emissions. The three supplementary firing options with the corresponding fuel used for the supplementary firing are: (i) partial gasification with char, (ii) full gasification with coal and (iii) full gasification with syngas. The performance of the IGCC system with these three options is compared with an option of the IGCC system without supplementary firing. Each supplementary firing option also involves pre-heating of the air entering the gas turbine combustion chamber in the gas cycle and reheating of the low-pressure steam in the steam cycle. The effects on coal consumption and CO 2 emissions are analysed by varying the operating conditions such as pressure ratio, gas turbine inlet temperature, air pre-heat and supplementary firing temperature. The results indicate that more work output is produced per unit mass of coal when there is no supplementary firing. Among the supplementary firing options, the full gasification with syngas option produces the highest work output per unit mass of coal, and the partial gasification with char option emits the lowest amount of CO 2 per unit mass of coal. Based on the analysis, the most advantageous option for low specific coal consumption and CO 2 emissions is the supplementary firing case having full gasification with syngas as the fuel.

A system performance and economics analysis of IGCC with supercritical steam bottom cycle supplied with varying blends of coal and biomass feedstock

“…Due to the immense increase in temperature from the subcritical case to the supercritical case, a duct burner is necessary to raise the temperature of the steam entering the steam turbine to the appropriate level. Therefore, the plant must make use of natural gas as a substitute fuel in order to achieve this high temperature. Both cases are shown in Figures and , respectively, both using 0% biomass in the feedstock.…”

Advanced Energy Systems and Energy Conservation Measures to Meet the Growing Energy Demand in a Sustainable Approach

“…Research investigations are conducted on IGCC systems to further improve their performance. Gnanapragasam et al, [5] reported the performance analysis for a coal gasification combined cycle power generation system as shown in Figure 2. There is also growing interest to develop IGCC systems with carbon capture and also with hydrogen production [6,7].…”

Pre-combustion carbon-capture technologies for power generation: an engineering-economic assessment

“…The economic viabilities of IGCC power plants with CO 2 capture has however been widely studied, along with several process configurations and feedstocks [15][16][17][18]. The pertinent published studies have covered the COE analysis for the performance of an IGCC power plant with Carbon Capture and Storage (CCS) with respect to several input parameters (e.g.…”