Steam Cracking Furnace and Process

Abstract

The present disclosure provides processes and apparatuses for cracking a hydrocarbon-containing feed. The process includes introducing the hydrocarbon-containing feed to a desalter preheat train having an effluent interchanger. The process includes directing a portion of the hydrocarbon-containing feed from in the desalter preheat train to a feed inlet of a convection section of a steam cracking furnace. The process includes combusting fuel proximate to a plurality of burners that provide thermal energy to a radiant section and a convection section of the steam cracking furnace. The hydrocarbon-containing feed is in an operating mode in the convection section to obtain a heated feed mixture. The process includes separating a bottoms effluent from the heated feed mixture of the convection section in a separator. The process includes cooling the bottoms effluent in a heat exchanger using boiler feed water.

1 . A steam cracking process comprising:
 introducing a hydrocarbon-containing feed to a desalter preheat train comprising an effluent interchanger;   directing at least a portion of the hydrocarbon-containing feed from the desalter preheat train to a feed inlet of a convection section of a steam cracking furnace;   combusting a fuel proximate to a plurality of burners that provide thermal energy to a radiant section of the steam cracking furnace and the convection section of the steam cracking furnace;   heating the hydrocarbon-containing feed in an operating mode in the convection section to obtain a heated feed mixture;   separating a bottoms effluent from the heated feed mixture of the convection section in a separator; and   cooling the bottoms effluent in a heat exchanger using boiler feed water.   
     
     
         2 . The process of  claim 1 , wherein the hydrocarbon-containing feed is provided to the effluent interchanger before and after introducing the hydrocarbon-containing feed to at least one desalter. 
     
     
         3 . The process of  claim 1 , further comprising controlling a temperature of the portion of the hydrocarbon-containing feed directed to the inlet of the convection section to the temperature and the temperature is within about 60° C. or less of a stack temperature of the steam cracking furnace. 
     
     
         4 . The process of  claim 3 , wherein the hydrocarbon-containing feed from the desalter preheat train to the inlet of the convection is about 85° C. to about 105° C. 
     
     
         5 . The process of  claim 1 , wherein the hydrocarbon-containing feed comprises a crude. 
     
     
         6 . The process of  claim 5 , wherein the hydrocarbon-containing feed, when introduced to the desalter preheat train to be heated, has a temperature of about 60° C. or less. 
     
     
         7 . The process of  claim 1 , wherein a stack temperature of the steam cracking furnace is less than about 150° C. 
     
     
         8 . The process of  claim 1 , further comprising introducing about 0.1 tph to about 2 tph of water to a portion of the convection section of the steam cracking furnace. 
     
     
         9 . The process of  claim 1 , wherein the hydrocarbon-containing feed comprises a heavy crude, a medium crude, or a combination thereof, and water is not introduced to the portion of the convection section during the combusting. 
     
     
         10 . The process of  claim 1 , wherein the hydrocarbon-containing feed comprises a medium crude, a light crude, or a combination of a medium crude and condensate, and the thermal energy provided to the radiant section and the convection section of the steam cracking furnace during the combusting is about 120 MW to about 130 MW. 
     
     
         11 . The process of  claim 1 , further comprising diverting steam from the heat exchanger to a steam header. 
     
     
         12 . The process of  claim 11 , further comprising providing a dilution steam from the steam header having a pressure of about 8 bar to about 15 bar to the convection section of the furnace. 
     
     
         13 . The process of  claim 11 , wherein cooling the bottoms effluent in the heat exchanger using boiler feed water comprises controlling a temperature of the bottoms effluent depending on a type of the hydrocarbon-containing feed and/or the temperature of the bottoms effluent. 
     
     
         14 . The process of  claim 11 , wherein cooling the bottoms effluent in the heat exchanger includes providing boiler feed water to the heat exchanger to provide a predetermined temperature of a bottom ½ height portion of the convection section, wherein the bottom ½ height portion is disposed between a NOx reduction bed and the radiant section of the furnace. 
     
     
         15 . The process of  claim 11 , wherein an amount of boiler feed water provided to the heat exchanger is determined based on a predetermined temperature of a NOx reduction bed disposed within the convection section of the furnace. 
     
     
         16 . The process of  claim 13 , wherein the bottoms effluent temperature is reduced by about 20° C. to about 50° C. in the heat exchanger. 
     
     
         17 . The process of  claim 1 , further comprising separating an overhead effluent from the heated feed mixture and introducing the overhead effluent to a bottom ½ height portion of the convection section. 
     
     
         18 . The process of  claim 1 , further comprising cooling a furnace effluent exiting the radiant section of the furnace with the boiler feed water to generate steam having a steam pressure of about 50 bar or greater, providing the steam to a steam drum and introducing the steam to portions of the furnace. 
     
     
         19 . The process of  claim 18 , further comprising introducing the furnace effluent to a knock out drum, condensing a product vapor from the knock out drum in a condenser to steam having a steam pressure of about 30 bar to 50 bar, generating power from the steam, and introducing boiler feed water to the condenser. 
     
     
         20 . The process of  claim 1 , further comprising providing boiler feed water to at least one heat recovery exchanger disposed in an upper ½ height portion of the convection section and preheating the boiler feed water with the thermal energy supplied by the plurality of burners. 
     
     
         21 . The process of  claim 20 , further comprising diverting the preheated boiler feed water to a steam drum. 
     
     
         22 . An apparatus comprising:
 a steam cracking furnace comprising a convection section and a radiant section;   a desalter preheat train coupled to a feed inlet of a convection section of the steam cracking furnace, the desalter preheat train comprising: an effluent interchanger, a trim preheater in fluid communication with the effluent interchanger, and at least one desalter in fluid communication with the trim heater, wherein the at least one desalter is in fluid communication with the effluent interchanger; and   a plurality of burners disposed within the steam cracking furnace capable of supplying thermal energy by combusting a fuel.   
     
     
         23 . The apparatus of  22 , further comprising a heat exchanger capable of cooling a boiler feed water, wherein the heat exchanger is capable of diverting a steam to a steam header. 
     
     
         24 . The apparatus of  23 , further comprising a controller capable of controlling and/or adjusting an amount of the steam diverted to the steam header. 
     
     
         25 . The apparatus of  claim 22 , further comprising a steam drum coupled to and capable of receiving preheated boiler feed water from a heat recovery exchanger disposed within an upper ½ height portion of the convection section of the steam cracking furnace. 
     
     
         26 . A steam cracking process comprising introducing a hydrocarbon-containing feed from a hydrocarbon-feed tank directly to a desalter preheat train; separating a first portion and a second portion of the hydrocarbon-containing feed in the desalter preheat train, wherein separating a first and second portion of the hydrocarbon-containing feed includes: introducing the hydrocarbon-containing feed in an effluent interchanger; preheating the hydrocarbon-containing feed from the effluent interchanger to a trim preheater in fluid communication with the effluent interchanger; separating a first portion and a second portion of the preheated effluent from the trim preheater to at least one desalter in fluid communication with the trim heater, wherein the at least one desalter is in fluid communication with the effluent interchanger; introducing the first portion of the preheated effluent to the effluent interchanger; directing the first portion of the preheated effluent from the desalter preheat train to a feed inlet of a convection section of a steam cracking furnace; and combusting a fuel at a plurality of burners to provide thermal energy to a radiant section of the steam cracking furnace and the convection section of the steam cracking furnace.