The invention relates to a plant and to a method for chemical looping oxidation-reduction combustion of a gaseous hydrocarbon feed, for example natural gas essentially containing methane. According to the invention, catalytic pre-reforming of the feed is performed in a pre-reforming zone comprising a fixed reforming catalyst, while benefiting from a heat transfer between the reduction or oxidation zone of the chemical loop and the pre-reforming zone adjoining the reduction or oxidation zone. Pre-reforming zone (130) and oxidation zone (110) or pre-reforming zone (130) and reduction zone (120) are thus thermally integrated within the same reactor (100) while being separated by at least one thermally conductive separation wall (140).