A system for manufacturing cement clinker which comprises: - a rotary thermally insulated kiln, - a main burner placed in a first end of the rotary thermally insulated tube configured to produce a flame injecting gases into the rotary thermally insulated kiln, - at least one riser duct placed in the second end of the rotary thermally insulated kiln, and an additional energy supply system to the kiln comprising: - a second burner located opposite to the main burner and with a penetration depth P1 into the rotary thermally insulated kiln above or equal to 0 meter, - at least an air blower, - a storage containing shredded fuel particles from wastes, - a shredded fuel dosing system located in the lower part of the storage, - a rotary valve, located between a connection chamber and the shredded fuel dosing system, - a connection chamber to which are connected the rotary valve and the air blower, and - a connection pipe placed between the connection chamber and the second burner, the system being arranged to burn the shredded fuel particles using the second burner so that shredded fuel particles have the main combustion in the at least one riser duct, characterized in that - the shredded fuel particles have a bulk density between 160 kg/m3 and 200 kg/m3, - the heat value of the shredded selected material is located between 2.5 and 5 Kcal/Kg, - the second burner, the rotary valve, the connection chamber are designed to enable up to 25% of total energy input in the rotary thermally kiln, - the air blower, the penetration depth P1 are configured so that the shredded particles will have a residential time in the kiln and in at least one riser duct higher than 2 seconds before reaching the upper part of at least one riser duct, and - the air blower, the penetration depth P1 are configured so that the shredded particles in the air flow can have an adjustable velocity V2 opposite to the velocity of the gases injected by the main burner located between 40m/s and 80m/s. - a rotary thermally insulated kiln, - a main burner placed in a first end of the rotary thermally insulated tube configured to produce a flame injecting gases into the rotary thermally insulated kiln, - at least one riser duct placed in the second end of the rotary thermally insulated kiln, and an additional energy supply system to the kiln comprising: - a second burner located opposite to the main burner and with a penetration depth P1 into the rotary thermally insulated kiln above or equal to 0 meter, - at least an air blower, - a storage containing shredded fuel particles from wastes, - a shredded fuel dosing system located in the lower part of the storage, - a rotary valve, located between a connection chamber and the shredded fuel dosing system, - a connection chamber to which are connected the rotary valve and the air blower, and - a connection pipe placed between the connection chamber and the second burner, - the shredded fuel particles have a bulk density between 160 kg/m3 and 200 kg/m3, - the heat value of the shredded selected material is located between 2.5 and 5 Kcal/Kg, - the second burner, the rotary valve, the connection chamber are designed to enable up to 25% of total energy input in the rotary thermally kiln, - the air blower, the penetration depth P1 are configured so that the shredded particles will have a residential time in the kiln and in at least one riser duct higher than 2 seconds before reaching the upper part of at least one riser duct, and - the air blower, the penetration depth P1 are configured so that the shredded particles in the air flow can have an adjustable velocity V2 opposite to the velocity of the gases injected by the main burner located between 40m/s and 80m/s.