Reducing carbon dioxide emissions in steam cracking operations

Abstract

A method for reducing CO2 emissions from steam cracking operations can include: introducing an oxygen-rich stream comprising oxygen and from 0 wt % to 15 wt % nitrogen to a vessel; introducing hydrocarbon combustion fuel to the vessel; combusting oxygen and hydrocarbon combustion fuel in the vessel to (1) produce a flue gas comprising carbon dioxide and water and (2) heat a cracking coil passing through the vessel; and performing a steam cracking reaction in the cracking coil passing through the vessel.

1 . A method comprising:
 introducing an oxygen-rich stream comprising oxygen and from 0 wt % to 15 wt % nitrogen to a vessel;   introducing hydrocarbon combustion fuel to the vessel;   combusting oxygen and hydrocarbon combustion fuel in the vessel to (1) produce a flue gas comprising carbon dioxide and water and (2) heat a cracking coil passing through the vessel; and   performing a steam cracking reaction in the cracking coil passing through the vessel.   
     
     
         2 . The method of  claim 1  further comprising:
 heating a steam coil and a hydrocarbon coil both passing through the vessel with the flue gas; and 
 supplying steam from the steam coil and hydrocarbon cracking feed from the hydrocarbon coil to the cracking coil. 
 
     
     
         3 . The method of claiml, wherein a temperature in the vessel at an outlet of the cracking coil from the vessel is about 600° C. to about 1000° C. 
     
     
         4 . The method of  claim 1 , wherein a pressure in the vessel at an outlet of the cracking coil from the vessel is about ambient pressure to about 600 psig. 
     
     
         5 . The method of  claim 4 , wherein a pressure in the vessel at an outlet of the cracking coil from the vessel is about 300 psig to about 600 psig. 
     
     
         6 . The method of  claim 1 , wherein a temperature in the cracking coil at an outlet of the cracking coil from the vessel is about 400° C. to about 900° C. 
     
     
         7 . The method of  claim 1 , wherein the oxygen is diluted with steam and/or carbon dioxide. 
     
     
         8 . The method of  claim 1 , wherein an excess of oxygen is used during combustion to produce the flue gas consisting essentially of carbon dioxide and water. 
     
     
         9 . The method of  claim 1  further comprising:
 condensing the water out of the flue gas to produce a water stream and a carbon dioxide stream, wherein the carbon dioxide stream comprises at least 75 wt % carbon dioxide. 
 
     
     
         10 . The method of  claim 10  further comprising:
 condensing the water out of the flue gas to produce a water stream and a carbon dioxide stream, wherein the carbon dioxide stream comprises at least 90 wt % carbon dioxide. 
 
     
     
         11 . The method of  claim 1 , wherein the hydrocarbon combustion fuel comprises a sulfur- containing contaminant, and the method further comprises:
 passing the flue gas through a selective amine scrubber.   
     
     
         12 . The method of  claim 1 , wherein a fluidized bed is present in the vessel. 
     
     
         13 . The method of  claim 1  further comprising:
 heating steam in a bottom coil passing through the vessel and located between the burners and the cracking coil. 
 
     
     
         14 . A system comprising:
 a vessel that contains burners and a cracking coil passing through the vessel;   an oxygen line that supplies an oxygen-rich stream comprising 0 wt % to 15 wt % nitrogen to the burners;   a hydrocarbon combustion fuel line that supplies hydrocarbon combustion fuel to the burners; and   a flue gas line that transports a flue gas comprising combustion product of the oxygen and hydrocarbon combustion fuel from the vessel.   
     
     
         15 . The system of  claim 14 , wherein the vessel is capable of being operated at a temperature in the vessel at an outlet of the cracking coil from the vessel is about 600° C. to about 1000° C. 
     
     
         16 . The system of  14 , wherein the vessel is capable of being operated at a pressure in the vessel at an outlet of the cracking coil from the vessel is about ambient pressure to about 600 psig. 
     
     
         17 . The system of  claim 16 , wherein the vessel is capable of being operated at a pressure in the vessel at an outlet of the cracking coil from the vessel is about 300 psig to about 600 psig. 
     
     
         18 . The system of  claim 14  further comprising:
 a line that supplies carbon dioxide and/or steam to the oxygen line to dilute the oxygen before being supplied to the burners. 
 
     
     
         19 . The system of  claim 14  further comprising:
 a condenser that receives the flue gas from the flue gas line and produces a water stream and a carbon dioxide stream. 
 
     
     
         20 . The system of  claim 14 , wherein the hydrocarbon combustion fuel comprises a sulfur-containing contaminant, and the system further comprises:
 a selective amine scrubber that receives the flue gas from the flue gas line.   
     
     
         21 . The system of  claim 14  further comprising:
 a steam coil that passes through the vessel to supply steam to the cracking coil; and 
 a hydrocarbon coil that passes through the vessel to supply hydrocarbon cracking feed to the cracking coil. 
 
     
     
         22 . The system of  claim 14  further comprising:
 a fluidized bed in the vessel. 
 
     
     
         23 . The system of  claim 14  further comprising:
 a bottom coil containing steam, passing through the vessel, and located between the burners and the cracking coil.