Processes and systems for removing deposits from an integrated plastic pyrolysis vessel and a steam cracking furnace

A process for removing deposits formed in a pyrolysis process using a pump-around loop, wherein the pump-around loop is in fluid communication with a vessel for cracking plastic, comprising:

• heating a hydrocarbon feed within a convection section of a steam cracking furnace and combining the hydrocarbon feed with an aqueous fluid to produce a first heated mixture comprising hydrocarbons and steam, wherein the heating is carried out before, during, and/or after the hydrocarbon feed is combined with the aqueous fluid;
• fluidly isolating a first end of the pump-around loop that is in fluid communication with the vessel and a second end of the pump-around loop that is in fluid communication with the vessel to provide a fluidly isolated section of the pump-around loop, wherein the fluidly isolated section comprises a first conduit disposed within the convection section of the steam cracking furnace or a heat exchanger that is external to the steam cracking furnace, and wherein the fluidly isolated section of the pump-around loop comprises char deposited on an inner surface of the first conduit;
• fluidly connecting the first end of the isolated section of the pump-around loop to an aqueous fluid source;
• fluidly connecting the second end of the isolated section of the pump-around loop to a second conduit disposed within the convection section of the steam cracking furnace;
• introducing an aqueous fluid from the aqueous fluid source into the first end of the isolated section of the pump-around loop;
• heating the aqueous fluid by flowing the aqueous fluid through the fluidly isolated section of the pump-around loop to produce a second heated mixture comprising steam and char;
• combining the second heated mixture with the first heated mixture to produce a third mixture;
• flowing the third mixture through the second conduit to produce a heated third mixture;
• and
• introducing the heated third mixture into a radiant section of the steam cracking furnace.

A process for removing deposits formed in a pyrolysis process using a pump-around loop, wherein the pump-around loop is in fluid communication with a vessel for cracking plastic, comprising:

• fluidly isolating a first end of the pump-around loop that is in fluid communication with the vessel, wherein the pump-around loop comprises a conduit disposed within a convection section of a steam cracking furnace or a heat exchanger that is external to the steam cracking furnace and has a second end in fluid communication with the vessel, and wherein the pump-around loop comprises char deposited on an inner surface of the conduit disposed within the convection section or the heat exchanger;
• fluidly connecting the first end of the pump-around loop to an aqueous fluid and/or oxidant source;
• introducing an aqueous fluid and/or an oxidant from the aqueous fluid and/or oxidant source into the first end of the pump-around loop;
• heating the aqueous fluid and/or oxidant by flowing the aqueous fluid and/or oxidant through the pump-around loop to produce a first heated mixture comprising steam, at least one of char and if the oxidant is present, any unreacted oxidant and a combustion product produced by combusting at least a portion of the char;
• introducing the first heated mixture into the vessel;
• obtaining a vapor phase overhead and a solid-containing bottoms material from the vessel;
• and
• introducing the vapor phase overhead into a radiant section of the steam cracking furnace.

A process for removing deposits formed in a pyrolysis process using a pump-around loop, wherein the pump-around loop is in fluid communication with a vessel for cracking plastic, comprising:

• heating a hydrocarbon feed within a convection section of a steam cracking furnace and combining the hydrocarbon feed with an aqueous fluid to produce a heated first mixture comprising hydrocarbons and steam, wherein the heating is carried out before, during, and/or after the hydrocarbon feed is combined with the aqueous fluid;
• fluidly isolating a first end of the pump-around loop that is in fluid communication the vessel, wherein the pump-around loop comprises a conduit disposed within the convection section of the steam cracking furnace or a heat exchanger that is external to the steam cracking furnace and has a second end in fluid communication with the vessel, and wherein the pump-around loop comprises char deposited on an inner surface of the conduit disposed within the convection section or the heat exchanger;
• fluidly connecting the first end of the pump-around loop to an aqueous fluid source;
• introducing an aqueous fluid from the aqueous fluid source into the first end of the pump-around loop;
• heating the aqueous fluid by flowing the aqueous fluid through the pump-around loop to produce a heated second mixture comprising steam and at least a portion of the char;
• introducing the heated second mixture into the vessel;
• obtaining a vapor phase overhead and a solid-containing bottoms material from the vessel;
• combining the vapor phase overhead with the heated first mixture to produce a third mixture;
• and
• introducing the third mixture into a radiant section of the steam cracking furnace.