The DemoCLOCK (Demonstration of a cost effective medium size Chemical Looping Combustion through packed beds using solid hydrocarbons as fuel for power production with CO2 capture) project is co-financed by the European Commission and is being developed by a consortium of 11 partners from 7 European countries. The objective of the project is to demonstrate the technical, economic and environmental feasibility for implementing packed bed based high temperature and high pressure chemical looping combustion in large-scale power plants. The aim of this paper is to present the preliminary results of a process simulation study of Integrated Gasification Chemical Looping Combustion (IG-CLC) plants, based on packed bed CLC reactors. The performance of complete IG-CLC power plants, including the coal gasification system, the CLC process and the power island, are predicted. Two configurations are addressed. In the first one, a gas-steam combined cycle is used, where the high temperature O2-depleted stream produced by a pressurized air reactor is expanded in a gas turbine. In the second option, power is generated by an advanced super critical steam cycle. The results obtained are reported in the paper and compared to competitive technologies considered by the EBTF (European Benchmarking Task Force). The results of the simulations indicate a high potential for this technology, with electric efficiencies 2.5 percentage points higher than the competitive IGCC plant with CO2 capture by physical absorption and more than 97% of CO2 avoided.