Partial trip system for ethylene furnace with ground flare

A method for operating a steam cracker, comprising:

• combusting fuel comprising a first fuel heating value in one or more burners of a steam cracker furnace to form a first flue gas, the furnace comprising a plurality of process tubes;
• passing a first feed comprising ethane and steam to the plurality of process tubes at a process tube inlet temperature of about 840° C. or more to form a product comprising ethylene, a volume ratio of steam to hydrocarbon in the feed being about 0.2 to about 0.5;
• separating an ethylene-containing stream from the product comprising ethylene in a water quench system;
• detecting a condition indicating a partial furnace trip is required;
• combusting, based on the detected condition, fuel comprising a second fuel heating value in the one or more burners to form a second flue gas, the second fuel heating value being 10% to 40% of the first fuel heating value;
• passing, based on the detected condition, a second feed comprising ethane and steam into the plurality of process tubes at a process tube inlet temperature of about 538° C. or more to produce an exit stream comprising ethane and steam, a volume ratio of steam to hydrocarbon in the second feed being about 0.2 to about 0.5, a ratio of a volume flow rate of the second feed relative to a volume flow rate of the first feed being about 0.3 to about 0.6;
• and
• directing at least a portion of the exit stream to a ground flare system.