Coking process and system for enhanced catalytic reactions to improve process operation and economics

Abstract

Heavy gas oil components, coking process recycle, and heavier hydrocarbons in the delayed coking process are cracked in the coking vessel by injecting a catalytic additive into the vapors above the gas/liquid-solid interface in the coke drum during the coking cycle. The additive may comprise cracking catalyst(s) and quenching agent(s), alone or in combination with seeding agent(s), excess reactant(s), carrier fluid(s), or any combination thereof to modify reaction kinetics to preferentially crack these components. The quenching effect of the additive may be effectively used to condense the highest boiling point compounds of the traditional recycle onto the catalyst(s), thereby focusing the catalyst exposure to these target reactants. Exemplary embodiments of the present invention may also provide systems and methods to (1) reduce coke production, (2) reduce fuel gas production, and (3) increase liquids production.

What is claimed is: 
     
         1 . A process comprising:
 introducing:
 1) excess reactant(s) containing hydrogen into a coker feed between a fractionator and a coker feed heater, in the coker feed heater, into a transfer line between a coker heater and coking vessel(s), into said coking vessel(s) of a delayed coking process, or any combination thereof; and 
 2) an additive comprising catalyst(s) into said coking vessel(s) of the delayed coking process during a coking cycle; 
   wherein said process promotes conversion of heavy hydrocarbons in said coking vessel(s).   
     
     
         2 . The process of  claim 1  where said additive further comprises seeding agent(s), excess reactant(s), quenching agent(s), carrier fluid(s), anti-foam fluid(s), or any combination thereof. 
     
     
         3 . The process of  claim 1  wherein said excess reactant(s) containing hydrogen comprises gaseous hydrogen, chemical compounds adapted to release reactive hydrogen at higher temperatures, Lewis Acids, Bronstead Acids, or any combination thereof. 
     
     
         4 . The process of  claim 3  wherein said excess reactant(s) containing hydrogen provides a 0.5:1 to 3:1 molar ratio of reactive hydrogen to coker feed. 
     
     
         5 . The process of  claim 3  wherein said excess reactant(s) containing hydrogen provides hydrogen to a targeted reaction zone at a rate of 30 to 600 Standard Cubic Feet per barrel of coker feed. 
     
     
         6 . The process of  claim 1  wherein said excess reactant(s) containing hydrogen promotes catalytic cracking, thermal cracking, or any combination thereof. 
     
     
         7 . The process of  claim 1  wherein said additive is added to vapors above a vapor-liquid interface in said coking vessel(s). 
     
     
         8 . The process of  claim 1  wherein said additive is added to said coking process by pressurized injection. 
     
     
         9 . The process of  claim 8  wherein a pressurized injection system is provided for adding said additive to said coking process that is selected from the group consisting of a pump with a feedback control system; a flow meter with a feedback control system; a modified anti-foam system; and any combination thereof. 
     
     
         10 . The process of  claim 8  wherein a pressurized injection system is provided for adding said additive to said coking process that is selected from the group consisting of positive displacement pumps; progressive cavity pumps; variable shearing mixing pumps; pumps with other control logic; pressure pots with pressurized fluid supplied by a host coker to push slurry into a coke drum; other devices adapted to increase slurry pressure in a tank or lines; and any combination thereof. 
     
     
         11 . The process of  claim 8  wherein a pressurized injection system is provided for adding said additive to said coking process that is a pump with control logic related to a pressure of said coking vessel(s). 
     
     
         12 . The process of  claim 8  wherein additive pressure is controlled such as to be above coking vessel(s) pressure. 
     
     
         13 . The process of  claim 12  wherein additive pressure is controlled by a pressure meter with a feedback control system. 
     
     
         14 . The process of  claim 12  wherein an additive pressure control is provided that is selected from the group consisting of a pressure feedback controller with a pressure indicator; pumps with a pressure measuring device to provide input to other control logic; pressure pots with pressurized fluid supplied by a host coker to push slurry into said coking vessel(s) with a pressure measuring device to control pressure of said pressurized fluid, additive(s), and/or any combination thereof; other devices to increase and/or control slurry pressure in a tank or lines; and any combination thereof. 
     
     
         15 . The process of  claim 12  wherein additive pressure is controlled by a variable shear mixing pump with a pressure measuring device that provides input to control logic related to a pressure of said coking vessel(s). 
     
     
         16 . The process of  claim 1  wherein additive introduction is controlled by a pressurized injection system comprising at least one spray nozzle. 
     
     
         17 . The process of  claim 16  wherein said at least one spray nozzle is selected from the group consisting of nozzles for slurry spray shapes; nozzles for slurry spray angles; nozzles for slurry droplet sizes; nozzles for slurry velocities; nozzles for slurry size openings; and any combination thereof. 
     
     
         18 . The process of  claim 1  wherein a control for additive introduction is provided that is selected from the group consisting of vertical or horizontal injection lances from top of drum with or without spray nozzle(s); modified drill stem adapted to precede a vapor/liquid interface as it moves upward in said coking vessel(s); modified drill stem with adjustable, movable nozzle to assure coverage of vapor/liquid interface at various vessel levels; retractable, horizontal or vertical injection lances in various drum locations; and any combination thereof 
     
     
         19 . The process of  claim 1  wherein components of said additive are combined by mixing that provides a sufficient level of blending said components prior to addition to said coking vessel(s) of said coking process. 
     
     
         20 . The process of  claim 19  wherein said components of said additive are mixed by a mixing device selected from the group consisting of a mixing tank with impeller; variable shear mixing pumps; static in-line mixers; pump inlet mixing devices; and any combination thereof. 
     
     
         21 . The process of  claim 19  wherein said components of said additive are mixed by a mixing device selected from the group consisting of continuous mixing devices; semi-continuous mixing devices; batch mixing devices; and any combination thereof. 
     
     
         22 . The process of  claim 1  wherein a temperature of said additive is regulated by a temperature control that provides a predetermined temperature level of said additive prior to addition to said coking vessel(s) of said coking process. 
     
     
         23 . The process of  claim 22  wherein said temperature control is selected from the group consisting of a heating coil in a mixing tank with heat media flow control and insulated piping; steam tracing or steam-jacketed additive lines with temperature control(s); electric heat tracing of additive lines with temperature control(s); temperature controls on each additive component or any combination thereof; and any combination thereof. 
     
     
         24 . The process of  claim 1  wherein a flow rate of said additive is controlled by a pressurized injection system; other flow meter(s) with other control logic; flow meter(s) with complex computer control logic; separate flow meters on additive components with control logic to achieve a desired combination of additive components; or any combination thereof. 
     
     
         25 . The process of  claim 24  wherein said flow rate of said additive is controlled by flow meters with complex control logic related to a feed rate of said coking vessel(s). 
     
     
         26 . The process of  claim 1  wherein said catalyst(s) lowers an energy required for cracking reactions, coking reactions, or any combination thereof. 
     
     
         27 . The process of  claim 1  wherein said catalyst(s) provides propagation of carbon based free radicals that facilitate cracking and coking reactions. 
     
     
         28 . The process of  claim 1  wherein said catalyst(s) comprises alumina, silica, zeolite, calcium, activated carbon, crushed pet coke, or any combination thereof. 
     
     
         29 . The process of  claim 1  wherein said catalyst(s) comprises new catalyst, FCCU equilibrium catalyst, spent catalyst, regenerated catalyst, pulverized catalyst, classified catalyst, impregnated catalysts, treated catalysts, or any combination thereof. 
     
     
         30 . The process of  claim 1 , wherein said catalyst(s) has particle size characteristics to prevent entrainment in vapors, to achieve fluidization in said coking vessel(s) and increase residence time in vapors, or any combination thereof. 
     
     
         31 . The process of  claim 1  wherein said catalyst(s) provides desired physical and chemical properties and/or characteristics selected from the group consisting of size to optimize catalyst settling characteristics in said coking vessel(s); porosity and activity combinations to optimize catalytic cracking of heavy hydrocarbons in liquid/foam layer(s) of a coking cycle; porosity and activity combinations to optimize catalytic cracking of hydrocarbons in product vapors in said coking vessel(s) during a coking cycle; and any combination thereof 
     
     
         32 . The process of  claim 1  wherein said catalyst(s) provides size distribution to optimize settling versus plugging of said catalyst(s). 
     
     
         33 . The process of  claim 1  further comprising cracking of said heavy hydrocarbons in said coking vessel(s) to lighter hydrocarbons that leave the coking vessel(s) as vapors and enter a downstream fractionator where said lighter hydrocarbons are separated into process streams that are useful in oil refinery product blending. 
     
     
         34 . The process of  claim 33  wherein said lighter hydrocarbon streams comprise naphtha, gas oil, gasoline, kerosene, jet fuel, diesel fuel, heating oil, or any combination thereof. 
     
     
         35 . The process of  claim 1  further comprising selecting or minimizing size of an additive system to locate as close to said coking vessel(s) as possible to limit line pressure drop and settling of catalyst in an injection system. 
     
     
         36 . The process of  claim 35  wherein said selection or minimization of size of said additive system includes: providing continuous mixing device in an additive injection system; designing additive injection system with major injection components, having optimal weight and system footprint to allow locating close to said coking vessel(s); using modified anti-foam system to limit new components or systems; or any combination thereof. 
     
     
         37 . The process of  claim 35  wherein said additive injection system is provided with vertical pump mounting to allow location close to said coking vessel(s) on a drilling deck. 
     
     
         38 . A process comprising:
 introducing:
 excess reactant(s) containing hydrogen into a coker feed between a fractionator and a coker feed heater, in the coker feed heater, into a transfer line between a coker heater and a coking vessel(s), into said coking vessel(s) of a delayed coking process, or any combination thereof; and 
 an additive by pressurized injection into said coking vessel(s) during a coking cycle of the delayed coking process to promote cracking of heavy hydrocarbons, wherein said additive comprises cracking catalyst(s), alone or in combination with seeding agent(s), excess reactant(s), quenching agent(s), carrier fluid(s), or any combination thereof; 
   wherein said hydrogen from said excess reactant(s) promotes cracking of the heavy hydrocarbons.