Steam Cracking with Supplemental Electrical Heating

Abstract

A hybrid steam cracking process including, in addition to combusting a fuel in a steam cracker furnace to provide thermal energy to the radiant and convection sections, heating a segment of an external furnace piping using an electrical heating device. The external furnace piping can include, e.g., the hydrocarbon-containing feed inlet piping, the cross-over piping, the radiant section inlet piping, and the radiant section outlet piping. Capacity and selectivity of the steam cracker furnace can be enhanced compared to conventional steam cracking process without electrical heating. The technology can be conveniently deployed in existing conventional steam cracking facilities.

What is claimed is: 
     
         1 . A process for steam cracking a hydrocarbon-containing feed, the process comprising:
 (I) providing a steam cracking furnace comprising a furnace enclosure, a plurality of burners housed in the furnace enclosure capable of supplying thermal energy by combusting a fuel, a hydrocarbon-containing feed inlet tube located outside of the furnace enclosure capable receiving a hydrocarbon-containing feed, a convection section located inside the furnace enclosure and coupled to the hydrocarbon-containing feed inlet tube, a cross-over section located outside of the furnace enclosure and coupled to an end of the convection section, a radiant section located inside the furnace enclosure and coupled to an end of the cross-over section via a radiant section inlet piping, a radiant section outlet piping coupled to the radiant section and located outside of the furnace enclosure, and one or more electrical heating devices capable of providing heat energy to an external furnace piping selected from: a segment of the hydrocarbon-containing feed inlet tube, a segment of the cross-over section, a segment of the radiant section inlet piping, and a segment of the radiant section outlet piping, and combinations thereof; wherein the radiant section inlet piping is located outside of the furnace enclosure;   (II) combusting the fuel at the plurality of the burners to provide thermal energy to the radiant section and the convection section;   (III) supplying electrical power to at least one of the one or more electrical heating devices to provide heat energy to the segment of the external furnace piping; and   (IV) in a cracking mode, feeding the hydrocarbon-containing feed through the hydrocarbon-containing feed inlet tube and optionally water and/or steam into the steam cracking furnace, heating the hydrocarbon-containing feed and/or the water/steam in the convection section to obtain a heated feed mixture, transferring the heated feed mixture from the convection section to the radiant section via the cross-over section and the radiant section inlet piping, cracking a plurality of hydrocarbons in the heated feed mixture in the radiant section to produce a cracked mixture exiting the steam cracking furnace through the radiant section outlet piping.   
     
     
         2 . The process of  claim 1 , wherein in step (III), a temperature of the segment of the external furnace piping is raised by deltaT ° C. by the heat energy provided by the at least one of the one or more electrical heating devices, where deltaT ranges from 10° C. to 200° C. 
     
     
         3 . The process of  claim 1 , wherein at least one, preferably all, of the one or more electrical heating devices comprise a resistor separate from the external furnace piping, and the resistor receives at least a portion of the electrical power and provides heat energy by resistive heating which is transferred to the external furnace piping. 
     
     
         4 . The process of  claim 1 , wherein at least one of the one or more electrical heating devices provides heat energy to the external furnace piping by induction heating. 
     
     
         5 . The process of  claim 1 , wherein at least one of the one or more electrical heating devices provides heat energy by radiant heating. 
     
     
         6 . The process of  claim 1 , wherein at least one, preferably all, of the one or more electrical heating devices takes a form of a heating jacket at least partly at least partly enclosing the external furnace piping. 
     
     
         7 . The process of  claim 1 , further comprising:
 (V) adjusting the electrical heating power of at least one of the one or more electrical heating devices to adjust the temperature of the external furnace piping.   
     
     
         8 . The process of  claim 1 , further comprising:
 (VI) monitoring a temperature of the external furnace piping; and   (VII) in steps (III) and (IV) and optionally (V), maintaining the temperature of the external furnace piping in a range from T(target)−15° C. to T(target)+15° C., where T(target) is a predetermined target temperature of the external furnace piping.   
     
     
         9 . The process of  claim 1 , wherein the one or more electrical heating devices include at least one electrical heating device providing heat energy to a segment of the cross-over section. 
     
     
         10 . The process of  claim 9 , wherein the one or more electrical heating devices include multiple electrical heating devices capable of being separately supplied with electrical power and capable of providing heat energy separately to multiple segments of the cross-over section. 
     
     
         11 . The process of  claim 9 , further comprising controlling and adjusting the electrical heating power of the at least one electrical heating devices to control and/or adjust the temperature of the cross-over section. 
     
     
         12 . The process of  claim 1 , wherein the one or more electrical heating devices include an electrical heating devices providing heat energy to a segment of the radiant section inlet piping. 
     
     
         13 . The process of  claim 12 , wherein the radiant section comprises multiple radiant tubes coupled separately to the multiple segments of the radiant section inlet piping, and the process further comprises separately controlling and/or adjusting the electrical heating power of the multiple electrical heating devices to separately control and/or adjust the temperatures of the multiple segments of the radiant section inlet piping, thereby separately controlling and/or adjusting the temperatures of multiple radiant tubes. 
     
     
         14 . The process of  claim 1 , wherein the one or more electrical heating devices include an electrical heating devices providing heat energy to a segment of radiant section outlet piping. 
     
     
         15 . The process of  claim 14 , wherein the radiant section comprises multiple radiant tubes coupled separately to the multiple segments of the radiant section outlet piping, and the process further comprises separately controlling and/or adjusting the electrical heating power of the multiple electrical heating devices to separately control and/or adjust the temperatures of the multiple segments of the radiant section outlet piping. 
     
     
         16 . The process of  claim 1 , wherein the radiant section outlet piping comprises a transfer line tube segment coupled at an end thereof with a transfer line heat exchanger and/or a quenching device, and the one or more electrical heating devices include an electrical heating device capable of being supplied with electrical power and capable of providing heat energy to the transfer line tube segment. 
     
     
         17 . The process of  claim 14 , wherein a fluid stream passing through the transfer line tube segment is maintained in a range from T(COT)−15° C. to T(COT)+15° C., where T(COT) is a predetermined temperature. 
     
     
         18 . The process of  claim 16 , wherein a fluid stream passing through the transfer line tube segment has a temperature from 15° C. to 200° C. higher than in a comparative process differing from the process only in that electrical power is not supplied to the one or more electrical heating devices capable of providing heat energy to the radiant section outlet piping and the transfer line tube. 
     
     
         19 . The process of  claim 1 , further comprising
 (VIII) in a decoking mode, feeding a decoking fluid into the radiant section;   wherein step (III) comprises supplying electric power to at least one electrical heating device capable of providing heat energy to a segment of the radiant section inlet piping.   
     
     
         20 . The process of  claim 19 , wherein step (III) comprises supplying electric power to multiple electrical heating devices capable of providing heat energy to multiple segments of the radiant section inlet piping. 
     
     
         21 . The process of  claim 20 , further comprising separately controlling and/or adjusting the electrical heating power of the multiple electrical heating devices to separately control and/or adjust the temperatures of the multiple segments of the radiant section inlet piping. 
     
     
         22 . The process of  claim 21 , wherein the radiant section comprises multiple radiant tubes coupled separately to the multiple segments of the radiant section inlet piping, and the process further comprises separately controlling and/or adjusting the electrical heating power of the multiple electrical heating devices to separately control and/or adjust the temperatures of the multiple segments of the radiant section inlet piping depending on the degree of coking inside the radiant tubes. 
     
     
         23 . The process of  claim 22 , wherein more heating power is provided by an electrical heating device to a segment of the radiant section inlet piping coupled to a radiant tube with higher degree of coking. 
     
     
         24 . The process of  claim 19 , wherein the decoking mode includes an online decoking operation. 
     
     
         25 . The process of  claim 19 , wherein the decoking mode includes an offline decoking operation. 
     
     
         26 . A process for steam cracking a hydrocarbon-containing feed, the process comprising one or more of the following:
 (I) providing a steam cracking furnace comprising: a furnace enclosure, a plurality of burners housed in the furnace enclosure capable of supplying thermal energy by combusting a fuel, a hydrocarbon-containing feed inlet tube located outside of the furnace enclosure capable receiving a hydrocarbon-containing feed, a convection section located inside the furnace enclosure and coupled to the hydrocarbon-containing feed inlet tube, a cross-over section located outside of the furnace enclosure and coupled to an end of the convection section, a radiant section located inside the furnace enclosure and coupled to an end of the cross-over section via a radiant section inlet piping, a radiant section outlet piping coupled to the radiant section and located outside of the furnace enclosure, and one or more electrical heating devices capable of providing heat energy to an external furnace piping selected from: a segment of the hydrocarbon-containing feed inlet tube, a segment of the cross-over section, a segment of the radiant section inlet piping, and a segment of the radiant section outlet piping, and combinations thereof; wherein the radiant section inlet piping is located outside of the furnace enclosure;   (II) combusting the fuel at the plurality of the burners to provide thermal energy to the radiant section and the convection section;   (III) supplying electrical power to at least one of the one or more electrical heating devices to provide heat energy to the segment of the external furnace piping; and   (VIII) in a decoking mode, feeding a decoking fluid into the radiant section; wherein step (III) comprises supplying electric power to at least one electrical heating device capable of providing heat energy to a segment of the radiant section inlet piping.