This paper presents results from a 30 -month project devoted to taking the chemical-looping combustion (CLC) technology to the next level of development. The project is part of the EU’s Sixth Framework programme with support from the CCP (Carbon Capture Project) and has mainly focused on the critical issues for an up-scaling of the technology. In an earlier project the CLC technology was demonstrated successfully for the first time for 100 h using Ni -based oxyge n carrier particles using natural gas as fuel. The current project has built on these experiences and : i) established industrial-scale NiO particle production with suitab le commercial raw materials. Oxygen carrier particles have been produced with both s pray -drying and impregnation and investigated extensively with respect to parameters important for CLC operation, such as reactivity in batch and continuous operation, strength, defluidization phenomena, operation at high temperatures and effect of imp urities suc h as H 2S in the fuel; ii) extended operational experience in long term tests of particles in the available 10 kW prototype for more than 1000 hours combustion and iii) succesfully scaled -up and operated the process in a 120 kWth combustor using syn gas and natural gas. Further, the project has included extended and verified modelling of the reactor system for scale-up in addition to process and technology scale-up and economic assessment. The paper will present the main results of the project.