Hybrid electric and fired heater for olefin production

Abstract

A process including preheating a hydrocarbon feed, feeding the preheated hydrocarbon stream to a second preheat zone for cracking, and feeding the cracking feed stream to one or more coils in a radiant section to recover a cracked hydrocarbon product. The process includes injecting excess air and cooling the cracked hydrocarbon product in a transfer line exchanger. The system includes a pyrolysis heater, a first and second preheat zone of the convection heating zone, and one or more coils in the radiant heating zone. The system includes one or more inlets for injecting an amount of excess air, one or more electrical heating elements in the radiant heating zone, and a feedline for directing the cracked hydrocarbon product to a transfer line exchanger.

What is claimed as new and desired to be protected by Letters Patent is: 
     
         1 . A pyrolysis process using a hybrid heater for converting a hydrocarbon mixture to produce olefins, the process comprising:
 preheating a hydrocarbon feed in a first preheat zone of a convection section, recovering a preheated hydrocarbon stream;   feeding the preheated hydrocarbon stream to a second preheat zone of the convection section to further heat the preheated hydrocarbon stream, recovering a cracking feed stream;   cracking hydrocarbons in the cracking feed stream in one or more coils in a radiant section comprising one or more fuel fired burners and one or more electrical heating elements, recovering a cracked hydrocarbon product;   injecting an amount of excess air in the convection section or the radiant section; and   cooling the cracked hydrocarbon product in a transfer line exchanger, recovering a cooled hydrocarbon product stream,   wherein the amount of excess air injected is in a range from about 10 mol % to 300 mol % excess air relative to a quantity of air required to combust fuel provided to the one or more fuel fired burners.   
     
     
         2 . The process of  claim 1 , further comprising:
 mixing a dilution steam stream with the preheated hydrocarbon stream, producing a mixed hydrocarbon-steam stream; and   feeding the mixed hydrocarbon-steam stream to the second preheat zone of the convection section and recovering the cracking feed stream.   
     
     
         3 . The process of  claim 1 , further comprising heating a combustion gas from the radiant section using one or more electrical heating elements in the convection section. 
     
     
         4 . The process of  claim 1 , further comprising:
 feeding a preheated air stream to the radiant section using one or more radiant section air inlet nozzles.   
     
     
         5 . The process of  claim 1 , further comprising:
 feeding a preheated air stream to the convection section using one or more convection section air inlet nozzles.   
     
     
         6 . The process of  claim 1 , further comprising preheating a second air stream in one or more air preheaters, electric heaters, or hot oil recirculation systems and feeding the second preheated air stream to the one or more fuel fired burners, preheating a burner fuel in one or more fuel preheaters, electric heaters, or hot oil recirculation systems, producing a preheated burner fuel, and feeding the preheated burner fuel to the one or more fuel fired burners, or both. 
     
     
         7 . The process of  claim 1 , further comprising feeding the cooled hydrocarbon product stream to a downstream recovery process. 
     
     
         8 . The process of  claim 1 , wherein at least a portion of the excess air is generated by a forced draft fan. 
     
     
         9 . The process of  claim 1 , wherein at least a portion of the excess air is preheated by an air preheater. 
     
     
         10 . The process of  claim 1 , wherein the convection section further comprises a plurality of electrical heating elements installed in one or more regions of the convection section. 
     
     
         11 . The process of  claim 1 , wherein the convection section further comprises a plurality of heat exchangers providing heat through a fluid flowing to low temperature regions of the convection section. 
     
     
         12 . The process of  claim 1 , wherein the amount of excess air injected is in a range from about 50 mol % to 300 mol % excess air. 
     
     
         13 . The process of  claim 1 , wherein the injecting an amount of excess air comprises feeding excess air to an air inlet disposed proximate the one or more fuel fired burners. 
     
     
         14 . The process of  claim 1 , wherein the injecting an amount of excess air comprises feeding excess air to the one or more fuel fired burners. 
     
     
         15 . The process of  claim 1 , wherein the injecting an amount of excess air comprises feeding excess air to an air inlet in the convection section. 
     
     
         16 . The process of  claim 1 , wherein the injecting an amount of excess air comprises feeding excess air to an air inlet disposed proximate the one or more electric heaters in the radiant section. 
     
     
         17 . A pyrolysis system using a hybrid heater for converting a hydrocarbon mixture to produce olefins, the system comprising:
 a pyrolysis heater comprising a convection heating zone and a radiant heating zone;   a first preheat zone of the convection heating zone configured for preheating a hydrocarbon feed and recovering a preheated hydrocarbon stream;   a second preheat zone of the convection heating zone configured for vaporizing a portion of the preheated hydrocarbon stream and recovering a cracking feed stream;   one or more coils in the radiant heating zone configured for cracking hydrocarbons in the cracking feed stream and recovering a cracked hydrocarbon product;   one or more inlets for injecting an amount of excess air in the convection heating zone or the radiant heating zone;   one or more electrical heating elements in the radiant heating zone configured for providing additional heat duty for cracking hydrocarbons; and   a feed line for directing the cracked hydrocarbon product to a transfer line exchanger for cooling cracked hydrocarbon product and recovering a cooled hydrocarbon product stream.   
     
     
         18 . The system of  claim 17 , further comprising a dilution steam stream inlet configured for providing a dilution steam stream to the preheated hydrocarbon stream between the first preheat zone and the second preheat zone. 
     
     
         19 . The system of  claim 17 , further comprising one or more electrical heating elements in the convection heating zone for heating a combustion gas from the radiant heating zone. 
     
     
         20 . The system of  claim 17 , further comprising:
 one or more radiant heating zone air inlet nozzles for feeding an air stream to the radiant heating zone.   
     
     
         21 . The system of  claim 17 , further comprising:
 one or more convection heating zone air inlet nozzles for feeding an air stream to the convection heating zone.   
     
     
         22 . The system of  claim 20 , further comprising a radiant heating zone air preheater configured to preheat an air stream fed to the radiant heating zone. 
     
     
         23 . The  system of 17 , further comprising a convection zone air preheater configured to preheat an air stream fed to the convection heating zone. 
     
     
         24 . The system of  claim 17 , wherein the one or more inlets for injecting is disposed proximate one or more fuel fired burners. 
     
     
         25 . The system of  claim 17 , wherein the one or more inlets for injecting is disposed proximate the one or more electric heaters in the radiant section. 
     
     
         26 . The system of  claim 17 , further comprising a product outlet for recovering the cooled hydrocarbon product stream and feeding the cooled hydrocarbon product stream to a downstream recovery process.