In the paper the results of analysis of an integrated gasification combined cycle IGCC polygeneration system, of which the task is to produce both electricity and synthesis gas, are shown. Assuming the structure of the system and the power rating of a combined cycle, the consumption of the synthesis gas for chemical production makes it necessary to supplement the lack of synthesis gas used for electricity production with the natural gas. As a result a change of the composition of the fuel gas supplied to the gas turbine occurs. In the paper the influence of the change of gas composition on the gas turbine characteristics is shown. In the calculations of the gas turbine the own computational algorithm was used. During the study the influence of the change of composition of gaseous fuel on the characteristic quantities was examined. The calculations were realized for different cases of cooling of the gas turbine expander’s blades (constant cooling air mass flow, constant cooling air index, constant temperature of blade material). Subsequently, the influence of the degree of integration of the gas turbine with the air separation unit on the main characteristics was analyzed.
 Chmielniak T.: The role of various technologies in achieving emissions objectives in the perspective of the years up to 2050. Rynek Energii 92(2011), 3-9 (in Polish).
 Franco A., Diaz A.R.: The future challenges for ‘clean coal technologies’: Joining effciency increase and pollutant emission control. Energy 34(2009), 348-350.
 Badyda K., Kupecki J., Milewski J.: Modelling of integrated gasification hybrid power systems. Rynek Energii 88(2010), 74-79.
 Kotowicz J., Skorek-Osikowska A., Bartela Ł.: Economic and environmental evaluation of selected advanced power generation technologies. Proc. Inst. Mech.Eng., Pt. A: J. Power Energy 225(2011), 3, 221-232.
 Pruschek R., Oeljeklaus G., Brand V., Haupt G., Zimmermann G., Ribberink J.S.: Combined cycle power plant with integrated coal gasification, CO shift and CO2 washing. Energy Convers. Manage. 36(1995), 797-800.
 Chiesa P„ Lozza G.: CO2 emission abatement in IGCC power plants by semi closed cycles: Part A - with oxygen-blown combustion. J. Eng. Gas Turb. Power 121(1999), 635-641.
 Chiesa P., Lozza G.: CO2 emissions abatement in IGCC power plants: Part B - with air blown combustion and CO2 physical absorption. J. Eng. Gas Turb. Power 121(1999), 642-648.
 Huang Y., Rezvani S., McIlveen-Wright D., Minchener A., Hewitt N.: Techno-economic study of CO2 capture and storage in coal fired oxygen fed entrained flow IGCC power plants. Fuel Process. Technol. 89(2008), 916-925.
 Gnanapragasam N., Reddy B., Rose M.: Reducing CO2 emissions for an IGCC power generation system: Effect of variations in gasifier and system operating conditions.Energy Convers. Manage. 50(2009), 1915-1923.
 Bartela Ł., Kotowicz J.: Analysis of work of gas turbine in IGCC system. Rynek Energii 95(2011), 16-22 (in Polish).
 Kotowicz J., Chmielniak T., Janusz-Szymańska K.: The influence of membrane CO2 separation on the efficiency of a coal-fired power plant. Energy 35(2010), 841-850.
 Kotowicz J., Skorek-Osikowska A., Janusz-Szymańska K.: Membrane separation of carbon dioxide In the integrated gasification combined cycle systems. Arch.Thermodyn. 31(2010), 145-164.
 Kotowicz J., Bartela Ł.: Optimisation of the connection of membrane CCS installation with a supercritical coal-fired power plant. Energy 38 (2012), 118-127.
 Kotowicz J., Janusz-Szymańska K.: The influence of CO2 membrane separation on the operating characteristics of a coal-fired power plant. Chem. Process. Eng. 34(2010), 681-697.
 Bartela Ł., Kotowicz J.: Influence of membrane CO2 separation process on the effectiveness of supercritical combined heat and power plant. Rynek Energii 97(2011), 6, 12-19 (in Polish).
 GateCycleTM. GE Enter Software, LLC, 1490 Drew Avenue, Suite 180, Davis, California 95616, U.S.A.
 Chmielniak T., Rusin A., Czwiertnia K.: Gas Turbines. Ossolineum, Wrocław 2001 (in Polish).
 Tabari A., Khaledi H., Benisi A.H.: Comperative evaluation of advanced gas turbine cycles with modified blade cooling models. In: Proc. GT2006, ASME Turbo Expo 2006: Power for Land, Sea and Air, Barcelona, May 8-11, 2006.
 He F., Li Z., Liu P., Ma L., Pistikopoulos E.N.: Operation window and part-load performance study of a syngas fired gas turbine. Appl. Energy 89(2012), 133-141.
 Lee J.J., Kim Y.S., Cha K.S., Kim T.S., Sohn J.L., Joo Y.J.: Influence of system integration options on the performance of an integrated gasification combined cycle power plant. Appl. Energy 86 (2009), 1788-1796.
 Kim Y.S., Lee J.J., Kim T.S., Sohn J.L., Joo Y.J.: Performance analysis of a syngas-fed gas turbine considering the operating limitations of its components. Appl.Energy 87(2010), 1602-1610.
 Facchini B., Ferrara G., Innocenti L.: Blade cooling improvement for heavy duty gas turbine: the air coolant temperature reduction and the introduction of steam and mixed steam/air cooling. Int. J. Therm. Sci. 39 (2000), 74-84.
 Kotowicz J., Bartela Ł.: The influence of economic parameters on the optimal values of the design variables of a combined cycle plant. Energy 35 (2010), 911-919.
 Kotowicz J, Bartela Ł.: The thermodynamic and economic optimization of a gas-steam Power plant by means of genetic algorithms. Rynek Energii 75(2008), 31-8 (in Polish).
 Remiorz L., Kotowicz J.: Restrictions of modelling process in gas-steam combined cycle. Rynek Energii 74 (2008), 42-47 (in Polish).