The attractiveness of fossil fuel as a feedstock for power generation depends on the development of energy conversion systems that are efficient, clean and economical. Coal fired power plants are generally considered to be “dirty” since they have high CO2 emissions, with the exception of those coal fired power plants that employ CO2 capture technology. Among the coal fired options, Integrated Gasification Combined Cycle (IGCC) systems have the best environmental performance and are potentially suitable candidates. The objective of this work is to provide an assessment and analysis of the potential for reduction of the output of greenhouse gas from the oxygen fed entrained flow gasifier systems, including the cost and cost-effectiveness of each likely conceptual scheme. The ECLIPSE process simulator was used successfully to perform technical, environmental and economic assessment studies for a wide range of IGCC power generation systems. Two IGCC power generation designs were selected, the Shell dry feed and GE (previously called Texaco) wet feed entrained flow gasifiers. As a reference fuel input, the American Federal coal was also used in IGCC systems. The performance of two IGCC systems was optimised within the constraint of being based on one particular advanced gas turbine and using a subcritical steam system. In this work, several IGCC plant attributes such as the fuel consumption, utility usages, plant performance as well as the specific CO2 generation and capture rates were simulated and weighed against each other. Factors affecting the IGCC plant performance, specifically net power output, process efficiency, power consumption coming from the Air Separation Unit (ASU) and CO2 removal and overall emissions were also evaluated and discussed. Finally, an economic evaluation of the system was conducted and the Costs Of CO2 capture plus transport are illustrated. This case study shows that the option of using IGCC for capturing CO2 could be technically feasible and cost-effective.