Two experimental studies were conducted with a novel moving granular bed filter (NMGBF). The first one was performed on a cold and dry mock-up module operated at room temperature and was aimed at a) proving the concept, b) establishing the operating patterns and flow profiles and c) optimizing the operating conditions. The gas flowrate and the geometry of the filter were the main variables studied. The second study was conducted on a prototype hot filter PDU (Process Development Unit) under real time operating conditions. The filter was one of the modules of a hot-gas-conditioning-train in a fluidized bed gasifier. Results showed similar particles collection efficiency for hot- and cold-dry filtration. The filter showed an efficiency of 99.9% over 55 h filtration time for particles larger than 1 mum, while for submicronic particles the efficiency is between 84% and 96% (weight basis). This paper presents and discusses the apparatus, the experimental methods and conditions as well as characteristic results on the two prototypes used.