Method and System for Steam Cracking

A steam cracking system comprising:

• one or more fired radiant sections;
• means configured to combust, during a steam cracking operation, a fuel with an oxidizer gas to heat the one or more fired radiant sections thereby forming a flue gas;
• means configured to form a process gas from a hydrocarbon feed and steam;
• means configured to pass the process gas through one or more cracking coils in the one or more fired radiant sections thereby forming a cracked gas;
• a flue gas heat recovery section configured to cool at least a part of the flue gas;
• and
• a cracked gas heat recovery section configured to cool at least a part of the cracked gas;
• wherein:
• the flue gas heat recovery section and the cracked gas heat recovery section each comprise one or more heat exchangers;
• the flue gas heat recovery section is configured such as to use, at least during a part of the steam cracking operation, a first proportion of more than 35% of a total amount of heat recovered within the one or more heat exchangers of the flue gas heat recovery section from the flue gas for preheating the oxidizer gas;
• the cracked gas heat recovery section comprises heat exchange structures which are provided in an amount and in a configuration configured such as to use, at least during the same part of the steam cracking operation, a second proportion of more than 35% of a total amount of heat recovered within the one or more heat exchangers of the cracked gas heat recovery section for preheating the process gas and/or the hydrocarbon feed and/or the process steam used in forming the process gas;
• the steam cracking system comprises a minimum of two separate oxidizer gas preheating stages configured to at least partially preheat the oxidizer gas, or a part thereof, against the flue gas in the flue gas heat recovery section;
• the steam cracking system is configured to use the flue gas in between the two oxidizer gas preheating stages to superheat high pressure steam at a pressure level between 30 and 175 bar absolute pressure;
• wherein the steam cracking system is configured to use saturated steam generated in a quench exchanger to preheat the process gas and/or the hydrocarbon feed and/or the process steam used in forming the process gas;
• and
• wherein the steam cracking system is configured to use condensate collected from said preheating using saturated steam for additional preheating of the process gas and/or the hydrocarbon feed and/or the process steam used in forming the process gas at a lower temperature level.