Thermal cracking of crudes to chemicals with heat transfer fluids

Abstract

Processes and systems for producing olefins from a crude oil include a steam cracking furnace having a radiant heating section and a convective heating section. One or more heating coils are disposed in the convective heating section for heating a heat transfer fluid. A first heat exchanger heats the crude oil with the heated heat transfer fluid, and the heated crude oil is desalted to form a desalted crude. A second heat exchanger heats the desalted crude with the heated heat transfer fluid to form a preheated desalted crude, which is separated in a first separator to recover a hydrocarbon vapor fraction and a hydrocarbon liquid fraction. A heating coil in the convective section superheats the hydrocarbon vapor fraction and a radiant heating coil in the radiant heating section thermally cracks the superheated vapor fraction to recover a first cracked effluent comprising olefins.

What is claimed as new and desired to be protected by Letters Patent is: 
     
         1 . A process for producing olefins from a crude oil, the process comprising:
 heating a high temperature stable heat transfer fluid in a convection section of a steam cracking furnace to generate a heated heat transfer fluid;   heating the crude oil via indirect heat exchange with the heated heat transfer fluid to form a heated crude oil;   desalting the crude oil to form a desalted crude;   heating the desalted crude to a first temperature via indirect heat exchange with the heated heat transfer fluid to form a pre-heated desalted crude;   separating the preheated desalted crude to recover a first hydrocarbon vapor fraction and a first hydrocarbon liquid fraction;   superheating the first hydrocarbon vapor fraction in a convective section of the steam cracking furnace to recover a first superheated vapor fraction;   thermally cracking the first superheated vapor fraction in a radiant section of the steam cracking furnace to recover a first cracked effluent comprising olefins.   
     
     
         2 . The process of  claim 1 , further comprising:
 heating the first hydrocarbon liquid via indirect heat exchange with the heated heat transfer fluid to form a heated first hydrocarbon liquid;   separating the heated first hydrocarbon liquid to recover a second hydrocarbon vapor fraction and a second hydrocarbon liquid fraction;   superheating the second hydrocarbon vapor fraction in a convective section of the steam cracking furnace to recover a second superheated vapor fraction;   thermally cracking the second superheated vapor fraction in a radiant section of the steam cracking furnace to recover a second cracked effluent comprising olefins.   
     
     
         3 . The process of  claim 2 , further comprising:
 heating the second hydrocarbon liquid via indirect heat exchange with the heated heat transfer fluid to form a heated second hydrocarbon liquid;   separating the heated second hydrocarbon liquid to recover a third hydrocarbon vapor fraction and a third hydrocarbon liquid fraction;   superheating the third hydrocarbon vapor fraction in a convective section of the steam cracking furnace to recover a third superheated vapor fraction;   thermally cracking the third superheated vapor fraction in a radiant section of the steam cracking furnace to recover a third cracked effluent comprising olefins.   
     
     
         4 . The process of  claim 1 , further comprising:
 circulating a first portion of the heat transfer fluid in a first heat transfer fluid circulation loop comprising a first heat exchange coil disposed in the convective section of the steam cracking furnace; and   circulating a second portion of the heat transfer fluid in a second heat transfer fluid circulation loop comprising a second heat exchange coil disposed in the convective section of the steam cracking furnace;   wherein heating the crude oil comprises heating the crude oil via indirect heat exchange with heated heat transfer fluid provided by the first circulation loop;   wherein heating the desalted crude comprises heating the desalted crude to the first temperature via indirect heat exchange with heated heat transfer fluid provided by the second circulation loop.   
     
     
         5 . The process of  claim 2 , further comprising:
 circulating a first portion of the heat transfer fluid in a first heat transfer fluid circulation loop comprising a first heat exchange coil disposed in the convective section of the steam cracking furnace;   circulating a second portion of the heat transfer fluid in a second heat transfer fluid circulation loop comprising a second heat exchange coil disposed in the convective section of the steam cracking furnace;   circulating a third portion of the heat transfer fluid in a third heat transfer fluid circulation loop comprising a third heat exchange coil disposed in the convective section of the steam cracking furnace;   wherein heating the crude oil comprises heating the crude oil via indirect heat exchange with heated heat transfer fluid provided by the first circulation loop;   wherein heating the desalted crude comprises heating the desalted crude to the first temperature via indirect heat exchange with heated heat transfer fluid provided by the second circulation loop; and   wherein heating the first hydrocarbon liquid comprises heating the first hydrocarbon liquid via indirect heat exchange with heated heat transfer fluid provided by the third circulation loop.   
     
     
         6 . The process of  claim 3 , further comprising
 circulating a first portion of the heat transfer fluid in a first heat transfer fluid circulation loop comprising a first heat exchange coil disposed in the convective section of the steam cracking furnace;   circulating a second portion of the heat transfer fluid in a second heat transfer fluid circulation loop comprising a second heat exchange coil disposed in the convective section of the steam cracking furnace;   circulating a third portion of the heat transfer fluid in a third heat transfer fluid circulation loop comprising a third heat exchange coil disposed in the convective section of the steam cracking furnace;   circulating a fourth portion of the heat transfer fluid in a fourth heat transfer fluid circulation loop comprising a fourth heat exchange coil disposed in the convective section of the steam cracking furnace;   wherein heating the crude oil comprises heating the crude oil via indirect heat exchange with heated heat transfer fluid provided by the first circulation loop;   wherein heating the desalted crude comprises heating the desalted crude to the first temperature via indirect heat exchange with heated heat transfer fluid provided by the second circulation loop;   wherein heating the first hydrocarbon liquid comprises heating the first hydrocarbon liquid via indirect heat exchange with heated heat transfer fluid provided by the third circulation loop; and   wherein heating the second hydrocarbon liquid comprises heating the second hydrocarbon liquid via indirect heat exchange with heated heat transfer fluid provided by the fourth circulation loop.   
     
     
         7 . The process of  claim 6 , further comprising electrically heating heat transfer fluid within one or both of the third and the fourth circulation loops. 
     
     
         8 . The process of  claim 6 , wherein the steam cracking furnace comprises two or more steam cracking furnaces. 
     
     
         9 . The process of  claim 8 , wherein
 a first steam cracking furnace of the two or more steam cracking furnaces includes heating coils associated with less than all of the first circulation loop, the second circulation loop, the third circulation loop, and the fourth circulation loop; and   wherein the first steam cracking furnace includes heating coils and radiant coils associated with less than all of the first vapor fraction, the second vapor fraction, and the third vapor fraction.   
     
     
         10 . The process of  claim 1 , wherein the steps of heating the crude oil and heating the desalted crude occur external to the steam cracking furnace. 
     
     
         11 . The process of  claim 1 , wherein no hydrocarbon liquids are heated in the convective section of the steam cracking furnace. 
     
     
         12 . The process of  claim 1 , further comprising heating combustion air, water, or steam via indirect heat exchange with the heated heat transfer fluid. 
     
     
         13 . A process for producing olefins from a wide boiling hydrocarbon mixture, the process comprising:
 heating a high temperature stable heat transfer fluid in a convection section of a steam cracking furnace to generate a heated heat transfer fluid;   heating the wide boiling hydrocarbon mixture via indirect heat exchange with the heated heat transfer fluid to form a heated hydrocarbon mixture;   separating the heated hydrocarbon mixture to recover a first hydrocarbon vapor fraction and a first hydrocarbon liquid fraction;   superheating the first hydrocarbon vapor fraction in a convective section of the steam cracking furnace to recover a first superheated vapor fraction;   thermally cracking the first superheated vapor fraction in a radiant section of the steam cracking furnace to recover a first cracked effluent comprising olefins;   heating the first hydrocarbon liquid via indirect heat exchange with the heated heat transfer fluid to form a heated first hydrocarbon liquid;   separating the heated first hydrocarbon liquid to recover a second hydrocarbon vapor fraction and a second hydrocarbon liquid fraction;   superheating the second hydrocarbon vapor fraction in a convective section of the steam cracking furnace to recover a second superheated vapor fraction;   thermally cracking the second superheated vapor fraction in a radiant section of the steam cracking furnace to recover a second cracked effluent comprising olefins.   
     
     
         14 . The process of  claim 13 , further comprising:
 heating the second hydrocarbon liquid via indirect heat exchange with the heated heat transfer fluid to form a heated second hydrocarbon liquid;   separating the heated second hydrocarbon liquid to recover a third hydrocarbon vapor fraction and a third hydrocarbon liquid fraction;   superheating the third hydrocarbon vapor fraction in a convective section of the steam cracking furnace to recover a third superheated vapor fraction;   thermally cracking the third superheated vapor fraction in a radiant section of the steam cracking furnace to recover a third cracked effluent comprising olefins.   
     
     
         15 . The process of  claim 13 , further comprising:
 circulating a first portion of the heat transfer fluid in a first heat transfer fluid circulation loop comprising a first heat exchange coil disposed in the convective section of the steam cracking furnace; and   circulating a second portion of the heat transfer fluid in a second heat transfer fluid circulation loop comprising a second heat exchange coil disposed in the convective section of the steam cracking furnace;   wherein heating the wide boiling hydrocarbon mixture comprises heating the wide boiling hydrocarbon mixture via indirect heat exchange with heated heat transfer fluid provided by the first circulation loop;   wherein heating the first hydrocarbon liquid comprises heating the first hydrocarbon liquid via indirect heat exchange with heated heat transfer fluid provided by the second circulation loop.   
     
     
         16 . The process of  claim 14 , further comprising:
 circulating a first portion of the heat transfer fluid in a first heat transfer fluid circulation loop comprising a first heat exchange coil disposed in the convective section of the steam cracking furnace;   circulating a second portion of the heat transfer fluid in a second heat transfer fluid circulation loop comprising a second heat exchange coil disposed in the convective section of the steam cracking furnace;   circulating a third portion of the heat transfer fluid in a third heat transfer fluid circulation loop comprising a third heat exchange coil disposed in the convective section of the steam cracking furnace;   wherein heating the wide boiling hydrocarbon mixture comprises heating the wide boiling hydrocarbon mixture via indirect heat exchange with heated heat transfer fluid provided by the first circulation loop;   wherein heating the first hydrocarbon liquid comprises heating the first hydrocarbon liquid via indirect heat exchange with heated heat transfer fluid provided by the second circulation loop; and   wherein heating the second hydrocarbon liquid comprises heating the second hydrocarbon liquid via indirect heat exchange with heated heat transfer fluid provided by the third circulation loop.   
     
     
         17 . The process of  claim 16 , further comprising electrically heating heat transfer fluid within one or both of the second and the third circulation loops. 
     
     
         18 . The process of  claim 13 , wherein no hydrocarbon liquids are heated in the convective section of the steam cracking furnace. 
     
     
         19 . The process of  claim 13 , further comprising heating combustion air, water, or steam via indirect heat exchange with the heated heat transfer fluid. 
     
     
         20 . A system for producing olefins from a crude oil, the system comprising:
 a steam cracking furnace including a radiant heating section and a convective heating section;   one or more heating coils disposed in the convective heating section for heating a high temperature stable heat transfer fluid to generate a heated heat transfer fluid;   a first heat exchanger for heating the crude oil via indirect heat exchange with the heated heat transfer fluid to form a heated crude oil;   a desalter for desalting the heated crude oil to form a desalted crude;   a second heat exchanger for heating the desalted crude to a first temperature via indirect heat exchange with the heated heat transfer fluid to form a pre-heated desalted crude;   a first separator for separating the preheated desalted crude to recover a first hydrocarbon vapor fraction and a first hydrocarbon liquid fraction;   a heating coil disposed in the convective section of the steam cracking furnace for superheating the first hydrocarbon vapor fraction to recover a first superheated vapor fraction;   a radiant heating coil in the radiant heating section of the steam cracking furnace for thermally cracking the first superheated vapor fraction to recover a first cracked effluent comprising olefins.   
     
     
         21 . The system of  claim 20 , further comprising:
 a third heat exchanger for heating the first hydrocarbon liquid via indirect heat exchange with the heated heat transfer fluid to form a heated first hydrocarbon liquid;   a second separator for separating the heated first hydrocarbon liquid to recover a second hydrocarbon vapor fraction and a second hydrocarbon liquid fraction;   a heating coil disposed in the convective section of the steam cracking furnace for superheating the second hydrocarbon vapor fraction to recover a second superheated vapor fraction;   a radiant heating coil in the radiant heating section of the steam cracking furnace for thermally cracking the second superheated vapor fraction to recover a second cracked effluent comprising olefins.   
     
     
         22 . The system of  claim 21 , further comprising:
 a fourth heat exchanger for heating the second hydrocarbon liquid via indirect heat exchange with the heated heat transfer fluid to form a heated second hydrocarbon liquid;   a third separator for separating the heated second hydrocarbon liquid to recover a third hydrocarbon vapor fraction and a third hydrocarbon liquid fraction;   a heating coil disposed in the convective section of the steam cracking furnace for superheating the third hydrocarbon vapor fraction to recover a third superheated vapor fraction;   a radiant heating coil in the radiant heating section of the steam cracking furnace for thermally cracking the third superheated vapor fraction to recover a third cracked effluent comprising olefins.   
     
     
         23 . The system of  claim 20 , further comprising:
 a first heat transfer fluid circulation loop including a circulating pump for circulating a first portion of the heat transfer fluid through a first heat exchange coil disposed in the convective section of the steam cracking furnace and to the first heat exchanger; and   a second heat transfer fluid circulation loop including a circulating pump for circulating a second portion of the heat transfer fluid through a second heat exchange coil disposed in the convective section of the steam cracking furnace and to the second heat exchanger.   
     
     
         24 . The system of  claim 21 , further comprising:
 a first heat transfer fluid circulation loop including a circulating pump for circulating a first portion of the heat transfer fluid through a first heat exchange coil disposed in the convective section of the steam cracking furnace and to the first heat exchanger; and   a second heat transfer fluid circulation loop including a circulating pump for circulating a second portion of the heat transfer fluid through a second heat exchange coil disposed in the convective section of the steam cracking furnace and to the second heat exchanger; and   a third heat transfer fluid circulation loop including a circulating pump for circulating a third portion of the heat transfer fluid through a third heat exchange coil disposed in the convective section of the steam cracking furnace and to the third heat exchanger.   
     
     
         25 . The system of  claim 24 , further comprising
 a first heat transfer fluid circulation loop including a circulating pump for circulating a first portion of the heat transfer fluid through a first heat exchange coil disposed in the convective section of the steam cracking furnace and to the first heat exchanger; and   a second heat transfer fluid circulation loop including a circulating pump for circulating a second portion of the heat transfer fluid through a second heat exchange coil disposed in the convective section of the steam cracking furnace and to the second heat exchanger;   a third heat transfer fluid circulation loop including a circulating pump for circulating a third portion of the heat transfer fluid through a third heat exchange coil disposed in the convective section of the steam cracking furnace and to the third heat exchanger; and   a fourth heat transfer fluid circulation loop including a circulating pump for circulating a fourth portion of the heat transfer fluid through a fourth heat exchange coil disposed in the convective section of the steam cracking furnace and to the fourth heat exchanger.   
     
     
         26 . The system of  claim 25 , further comprising an electric heater fluidly connected for electrically heating heat transfer fluid within one or both of the third and the fourth circulation loops. 
     
     
         27 . The system of  claim 24 , wherein the steam cracking furnace comprises two or more steam cracking furnaces. 
     
     
         28 . The system of  claim 27 , wherein
 a first steam cracking furnace of the two or more steam cracking furnaces includes heating coils associated with less than all of the first circulation loop, the second circulation loop, the third circulation loop, and the fourth circulation loop; and   wherein the first steam cracking furnace includes heating coils and radiant coils associated with less than all of the first vapor fraction, the second vapor fraction, and the third vapor fraction.   
     
     
         29 . The system of  claim 25 , further comprising a flow line for bypassing one or both of the second separator and the third separator. 
     
     
         30 . The system of  claim 20 , wherein the steam cracking furnace comprises no heating coils fluidly connected for heating hydrocarbon liquids in the convective section of the steam cracking furnace. 
     
     
         31 . The system of  claim 20 , further comprising one or more heating exchangers for heating combustion air, water, or steam via indirect heat exchange with the heated heat transfer fluid.