Electrically heated cracking furnance and thermal energy recovery device

Abstract

A method to produce olefins may include supplying a hydrocarbon feed to an outer tube of a thermal energy recovery assembly; heating the hydrocarbon feed in the outer tube of the thermal energy recovery assembly to output a preheated hydrocarbon feed; supplying the preheated hydrocarbon feed to an electrically powered cracking furnace comprising a reaction zone to heat the preheated hydrocarbon feed; cracking the preheated hydrocarbon feed in the reaction zone of the electrically heated cracking furnace using heat generated by electricity to output hot reactor effluent comprising cracked hydrocarbons and olefins; supplying the hot reactor effluent to an inner tube of the thermal energy recovery assembly; and cooling the hot reactor effluent in the inner tube of the thermal energy recovery assembly by transferring heat to the hydrocarbon feed.

What is claimed is: 
     
         1 . A method to produce olefins, the method comprising:
 supplying a hydrocarbon feed to an outer tube of a thermal energy recovery assembly;   heating the hydrocarbon feed in the outer tube of the thermal energy recovery assembly to output a preheated hydrocarbon feed;   supplying the preheated hydrocarbon feed to an electrically powered cracking furnace comprising a reaction zone to heat the preheated hydrocarbon feed;   cracking the preheated hydrocarbon feed in the reaction zone of the electrically heated cracking furnace using heat generated by electricity to output hot reactor effluent comprising cracked hydrocarbons and olefins;   supplying the hot reactor effluent to an inner tube of the thermal energy recovery assembly; and   cooling the hot reactor effluent in the inner tube of the thermal energy recovery assembly by transferring heat to the hydrocarbon feed.   
     
     
         2 . The method according to  claim 1 , further comprising:
 supplying an additional feed different than the hydrocarbon feed to the outer tube of the thermal energy recovery assembly; and   heating the additional feed by transferring heat from the hot reactor effluent to the additional feed via the thermal energy recovery assembly.   
     
     
         3 . The method according to  claim 1 , further comprising:
 withdrawing a partially preheated hydrocarbon feed from the outer tube of the thermal energy recovery assembly;   feeding the partially preheated hydrocarbon feed to the thermal energy recovery assembly; and   further heating the partially preheated hydrocarbon feed by transferring heat from the hot reactor effluent via the thermal energy recovery assembly, to output the preheated hydrocarbon feed.   
     
     
         4 . The method according to  claim 1 , further comprising cooling the hot reactor effluent at a rate of at least 2.5 degrees Kelvin/millisecond, at least 3.5 degrees Kelvin/millisecond, or at least 4.5 degrees Kelvin/millisecond. 
     
     
         5 . The method according to  claim 1 , wherein a pressure drop of the hot reactor effluent passing through the thermal energy recovery assembly is less than 0.35 bar, less than 0.30 bar, less than 0.25 bar, less than 0.20 bar, or less than 0.15 bar. 
     
     
         6 . The method according to  claim 1 , wherein a residence time of the hot reactor effluent within the thermal energy recovery assembly is less than 100 milliseconds, less than 95 milliseconds, less than 90 milliseconds, less than 85 milliseconds, is less than 83 milliseconds, or is less than 80 milliseconds. 
     
     
         7 . The method according to  claim 1 , wherein a pressure drop of the feed passing through the thermal energy recovery assembly is from 2 to 15 bar, from 2.5 to 10 bar, from 3 to 8 bar, from 3 to 10 bar, from 4 to 9 bar, or from 5 to 8 bar. 
     
     
         8 . A thermal energy recovery assembly for operating the method according to  claim 1 , the thermal energy recovery assembly comprising:
 an outer tube; and   an inner tube;   wherein a hydrocarbon feed is supplied to an electrically powered cracking furnace comprising a reaction zone to heat the hydrocarbon feed;   wherein the inner tube comprises a first inlet configured to receive the hot reactor effluent from the electrically powered cracking furnace; and   wherein the outer tube is disposed about the inner tube to enclose an annulus about the inner tube, the annulus comprising a second inlet configured to receive the hydrocarbon feed.   
     
     
         9 . The thermal energy recovery assembly according to  claim 8 , wherein the annulus comprises at least one heat transfer enhancement to enhance heat transfer from the inner tube to the annulus. 
     
     
         10 . The thermal energy recovery assembly according to  claim 9 , wherein the annulus comprises a first stage, and the at least one heat transfer enhancement comprises one or more of impingement, turbulence promotion, high-shear-inducing geometry, or increased surface area. 
     
     
         11 . The thermal energy recovery assembly according to  claim 10 , wherein the annulus comprises a plate impingement between an upstream end and a downstream end, the plate impingement comprising:
 a first channel having a stage inlet at the upstream end and being closed to flow at the downstream end;   a second channel having a stage outlet at the downstream end, the second channel being disposed between the first channel and the inner tube;   a wall separating the first channel from the second channel, the wall defining openings to fluidly connect the first channel and the second channel; and   the plate impingement being configured to receive feed through the stage inlet, flow feed from the first channel to the second channel via the openings of the wall, and causing flow of the feed to impinge onto an outer surface of the inner tube and exhaust feed through the stage outlet of the second channel.   
     
     
         12 . The thermal energy recovery assembly according to  claim 10 , wherein the annulus comprises a piccolo impingement, the piccolo impingement comprising:
 an upstream divider disposed about the inner tube and within the outer tube;   a downstream divider disposed about the inner tube and within the outer tube downstream of the upstream divider within the annulus, the downstream divider defining at least one stage outlet;   a chamber defined within the outer tube and about the inner tube between the upstream divider and the downstream divider; and   piccolo tubes offset from the inner tube, the piccolo tubes extending through the chamber from the upstream divider to the downstream divider, the piccolo tubes including a stage inlet for receiving incoming feed, the piccolo tubes including a plurality of openings defined therein, the piccolo impingement being configured to receive feed from the stage inlets, flow feed from the piccolo tubes into the chamber via the plurality of openings, and exhaust feed from the chamber via the at least one stage outlet.   
     
     
         13 . The thermal energy recovery assembly according to  claim 9 , wherein the annulus comprises at least a first stage and a second stage, wherein the first stage and the second stage are in series, wherein both stages comprise at least one heat transfer enhancement. 
     
     
         14 . The thermal energy recovery assembly according to  claim 8 , wherein the inner tube comprises a heat transfer enhancement comprising one or more of turbulence promotion, high-shear-inducing geometry, or increased surface area. 
     
     
         15 . The thermal energy recovery assembly according to  claim 9 , wherein the thermal energy recovery assembly comprises a plurality of inner tubes parallel with one another with each inner tube disposed within an outer tube, each outer tube having one or more of impingement, turbulence promotion, high-shear-inducing geometry, or increased surface area to enhance heat transfer from the inner tube to an annulus defined within the outer tube. 
     
     
         16 . Use of a thermal energy recovery assembly according to  claim 8 .