TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The redox active material comprises 0.1-10 mass% nickel. The manganese ore comprises 70-90 mass%, preferably 76-82 mass% of manganese dioxide. The nickel-manganese mixed metallic oxide is nickel manganite (preferred) or manganese nickel oxide. The redox active material comprises a mixture pyrolusite type natural manganese ore particles and nickel oxide particles, and more than 90% of the particles have a particle size of 100-500 mu m, preferably 150-300 mu m. Preferred Method: The redox active material is thermally treated at 800-1200 degrees C for 0.5 hour to 10 days during or after the installation of the chemical loop, and has specific particles size that is applicable in a fluidized bed. The natural manganese ore is crushed and filtered to obtain particles. The method further comprises: injecting hydrocarbon loads into a first reaction zone (R1) operating in the fluidized bed, with the particles of redox active material; combusting gas effluents output from of the first reaction zone in a second reaction zone (R2) with the presence of the particles of redox active material; dividing the flow of particles of the active mass output from of the second reaction zone into the second reaction zone through a first under-flow path, and into an oxidation zone (R4) through a second under-flow path in a first division zone (R3); performing the reoxidation of the particles of the active material in the oxidation zone before returning them towards the first reaction zone; and dividing the flow of particles of the active material output from of the oxidation zone again into the oxidation zone through a third under-flow path and into the first reaction zone through a fourth under-flow path in a second division zone (R5). The grain size of nickel oxide particle is different from the grain size of natural manganese ore. The redox active material is activated at greater than or equal to 600 degrees C, preferably greater than or equal to 900 degrees C in an oxidizing atmosphere. The reduction of the redox active material in contact with the hydrocarbon load is carried out at 600-1400 degrees C. EXAMPLE - No suitable example given.