Efficient cracking furnace system with reduced emission of CO2

A cracking furnace system for converting a hydrocarbon feedstock into cracked gas, the cracking furnace system comprising:

• a first flow path for flowing a hydrocarbon feedstock through the cracking furnace;
• a second flow path for flowing a diluent through the cracking furnace;
• a convection section disposed in the first flow path and the second flow path configured to receive only the hydrocarbon feedstock and the diluent to preheat the hydrocarbon feedstock and the diluent;
• a mixing device disposed in the first flow path and the second flow path configured and adapted to mix the preheated hydrocarbon feedstock and the preheated diluent to generate a feedstock-diluent mixture, wherein the mixing device is disposed between the convection section and a second transfer line exchanger;
• a radiant section disposed in the first flow path downstream of the mixing device, the radiant section having a firebox, the firebox comprising one or more pure oxygen burners and a plurality of serpentine radiant coils configured to heat the feedstock-diluent mixture to a temperature allowing a pyrolysis reaction;
• and
• a cooling section having a first transfer line exchanger and the second transfer line exchanger,
• wherein the first transfer line exchanger is disposed in the first flow path downstream of the radiant section such that cracked gas exiting the radiant section is quenched via heat exchange with boiler feed water generating steam and quenched cracked gas, and wherein the second transfer line exchanger is disposed in the first flow path upstream of the radiant section and downstream of the first transfer line exchanger such that the feedstock-diluent mixture is preheated in the second transfer line exchanger via heat exchange with the quenched cracked gas exiting the first transfer line exchanger before the feedstock-diluent mixture enters into the radiant section and the quenched cracked gas exiting the first transfer line exchanger is further cooled with the feedstock-diluent mixture in the second transfer line exchanger.