Performance maximization of IGCC plant considering operating limitations of a gas turbine and ambient temperature

We predicted the available maximum power output of Integrated gasification combined cycle (IGCC) plants under the operating limitations of a gas turbine. The power block of the IGCC using an F-class gas turbine was modeled, and its interactions of mass and energy with other components such as a gasifier and an air separation unit were considered. Variation in the gas turbine power output with nitrogen dilution was simulated, and the operating conditions under which the power should be limited below an allowable maximum were determined. The maximum net power output of the IGCC plant under the restrictions of syngas turbine power (232 MW) and blade temperature were estimated in a wide range in terms of ambient temperature and integration degree, and the optimal integration degree for each ambient temperature is suggested. At relatively high temperatures over 19°C, zero integration degree (air for the air separation unit is supplied solely from the ambient) provides the highest net power output and efficiency. As ambient temperature decreases, a higher integration degree provides higher net power. The optimal net IGCC power output varies from 260 MW to 347 MW (33%) in the ambient temperature range of 40°C to -10°C, while the optimal net efficiency varies by about one percentage point.