This Dataset include data of: fluidised bed (FB) cycling experiments of NiO/Ca2Fe2O5/CaO, TGA experiments, XRD results, FTIR measurement and H2 activation in fluidised bed. The raw/collected data (in xls. format) of gas measurement from CH4/CO2 FB cycling experiments contains results over 40 cycles at 700oC and 900oC respectively. The collected gas includes CO2, CO, CH4, H2 and O2. The data were processed on an hourly basis. The XRD data of fresh and used/cycled samples of NiO/Ca2Fe2O5/CaO included additional Aluminium peaks due to the use of Aluminium mount, so the processing of the raw data requires the removal of Aluminium peaks. The collected cycling experiments in TGA were also provided in xls. and processed on a minute basis. The mass has been normalised based on the initial mass. FTIR spectrums of the gas flow during the CH4 processing stage in TGA runs were collected. The bottom tabs (sub-sheets) within the xls. show the spectrum results at different times from the beginning to the end of the CH4 processing. The negative CO2 peaks, coming from background fluctuation over time, need to be removed to reflect the actual signals from the TGA gas stream. The details for interpretation and other results/data of material characterisation (SEM-EDS, XRD comparison with reference peaks from ICSD database) can be found in the main paper.