A 4MW chemical looping combustion (CLC) unit was designed, built, operated and demonstrated in the city of Deyang in China under the funding China's Ministry of Science and Technology (MOST) and EU's Horizon2020. The air reactor was designed as fast fluidized bed and the fuel reactor was turbulent fluidized bed. The solid circulation between the fuel and air reactors is controlled by the overflow method, and an overflow port is installed in the fuel reactor. The static bed height in the fuel reactor is higher than the overflow port to prevent it from constraining the solid circulation rate. The oxygen carrier from the air reactor cyclone return back into the fuel reactor riser and are transported up into the carbon stripper above the fuel reactor to convert the unburnt gases released from the fuel reactor. A cold flow mock-up equivalent to a 1.5 MWth CLC unit was built and operated to provide detailed quantitative information of reactor hydrodynamics, solid circulation control between air reactor and fuel reactor, transport of oxygen carrier in air reactor. A 4 MW demonstration pilot was built with the total height of 50 meters on the May of 2022. From June 2023, the 4 MW demonstration was operated and test continuously with auto thermal. This presentation will provide the latest auto thermal operational results and data of this 4MW CLC pilot with lignite as fuel.