Method and plant for chemical looping oxidation-reduction combustion of a gaseous hydrocarbon feedstock with intermediate catalytic steam reforming of the feed

A method for chemical looping oxidation-reduction combustion of a gaseous hydrocarbon feed, comprising:

• sending gaseous hydrocarbon feed to a first fluidized-bed reduction zone to perform partial combustion of said gaseous hydrocarbon feed on contact with a first stream of particles of a redox active mass,
• separating the redox active mass particles and a gas stream contained in a mixture coming from the first reduction zone in order to send said gas stream to a reforming zone,
• carrying out catalytic steam reforming of said gas stream in the reforming zone comprising a reforming catalyst fixed bed in order to produce a gaseous effluent comprising syngas,
• sending said gaseous effluent to a second fluidized-bed reduction zone to perform combustion of said gaseous effluent on contact with a second stream of particles of a redox active mass,
• oxidizing the redox active mass particles that have stayed in the first and second reduction zones by contacting with an oxidizing gas stream in a fluidized-bed oxidation zone.