Fluidized coking with catalytic gasification

Abstract

Systems and methods are provided for integrating a fluidized coking process with a catalyst-enhanced coke gasification process. The catalyst for the gasification process can correspond to calcium oxide, a thermally decomposable calcium salt, a potassium salt such as potassium carbonate, or a combination thereof. Examples of suitable calcium salts can include, but are not limited to, calcium hydroxide, calcium nitrate, and calcium carbonate. The calcium oxide, potassium salts, and/or thermally decomposable calcium salts can be introduced into the integrated system, for example, as part of the feed into the coker. It has been unexpectedly discovered that using catalytic gasification as part of an integrated fluidized coking and gasification process can result in an overhead gas stream from the gasifier with increased energy content and/or overhead gas pressure.

1 . A method for performing fluidized coking on a feed, comprising:
 exposing a feedstock comprising a T10 distillation point of 343° C. or more to a fluidized bed comprising solid particles in a reactor under coking conditions to form a coker effluent, the thermal cracking conditions comprising 10 wt % or more conversion of the feedstock relative to 343° C., the thermal cracking conditions being effective for depositing coke on the solid particles, the exposing further comprising introducing potassium carbonate, calcium oxide, one or more thermally decomposable calcium salts, or a combination thereof into the fluidized bed comprising solid particles;   introducing an oxygen-containing stream and steam into a gasifier;   passing at least a portion of the solid particles comprising deposited coke from the reactor to the gasifier;   exposing the at least a portion of the solid particles comprising deposited coke to gasification conditions in the presence of at least a portion of the steam, oxygen from the oxygen-containing stream, and potassium carbonate, calcium oxide, or a combination thereof to form partially gasified solid particles and a gas phase product comprising Hz, CO, and CO 2 , the gasification conditions comprising a temperature of 1200° F. to 1400° F. (˜650° C. to ˜760° C.) and a pressure of 20 psig to 600 psig (˜140 kPa-g to ˜4100 kPa-g);   removing at least a first portion of the partially gasified solid particles from the gasifier; and   passing at least a second portion of the partially gasified solid particles from the gasifier to the reactor.   
     
     
         2 . The method of  claim 1 , wherein the solid particles comprise coke particles. 
     
     
         3 . The method of  claim 2 , wherein at least a portion of the potassium carbonate, calcium oxide, or combination thereof comprises potassium carbonate, calcium oxide, or a combination thereof deposited on the at least a portion of the solid particles, the first portion of the partially gasified solid particles, the second portion of the partially gasified solid particles, or a combination thereof. 
     
     
         4 . The method of  claim 1 , wherein the potassium carbonate, calcium oxide, one or more thermally decomposable calcium salts, or a combination thereof is entrained in the feedstock. 
     
     
         5 . The method of  claim 1 , wherein introducing potassium carbonate, calcium oxide, one or more thermally decomposable calcium salts, or a combination thereof into the fluidized bed of solid particles comprises:
 introducing the potassium carbonate, calcium oxide, one or more thermally decomposable calcium salts, or a combination thereof into the fluidized bed of solid particles in a carrier fluid different from the feedstock.   
     
     
         6 . The method of  claim 1 , wherein the feedstock comprises a first portion and a second portion, and wherein the second portion of the feedstock comprises the potassium carbonate, calcium oxide, thermally decomposable calcium salt, or a combination thereof, the second portion of the feedstock further comprising a carrier fluid. 
     
     
         7 . The method of  claim 1 , wherein the one or more thermally decomposable calcium salts comprise calcium nitrate, calcium carbonate, calcium hydroxide, or a combination thereof. 
     
     
         8 . The method of  claim 1 , wherein the feedstock comprises 0.01 wt % to 0.5 wt % of the potassium carbonate, calcium oxide, one or more thermally decomposable calcium salts, or a combination thereof. 
     
     
         9 . The method of  claim 1 , wherein the potassium carbonate, calcium oxide, or combination thereof comprises supported potassium catalyst particles, supported calcium catalyst particles, or a combination thereof. 
     
     
         10 . The method of  claim 9 , further comprising recovering the supported potassium catalyst particles, the supported calcium catalyst particles, or a combination thereof and recycling the supported potassium catalyst particles, the supported calcium particles, or a combination thereof to at least one of the reactor and the gasifier. 
     
     
         11 . The method of  claim 1 , wherein the coking conditions comprise a temperature of 950° F. to 1100° F. (˜510° C. to ˜595° C.) and a pressure of 20 psig to 600 psig (˜140 kPa-g to ˜4100 kPa-g). 
     
     
         12 . The method of  claim 1 , wherein the gasification conditions comprise a pressure of 200 psig to 600 psig (˜1400 kPa-g to ˜4100 kPa-g). 
     
     
         13 . The method of  claim 1 , wherein the first portion of partially gasified solid particles comprises a first weight percentage of metals (optionally a first combined weight percentage of Ni, V, Fe), relative to a weight of the first portion of partially gasified coke particles, that is greater than a weight percentage of metals (optionally a combined weight percentage of Ni, V, Fe) in the feedstock, relative to a weight of the feedstock. 
     
     
         14 . The method of  claim 1 , wherein the exposing the at least a portion of the solid particles comprising deposited coke to gasification conditions results in cumulative deposition of less than 0.1 wt % of metals on the gasifier wall, relative to the feedstock's cumulative metals content. 
     
     
         15 . The method of  claim 1 , wherein passing at least a second portion of the partially gasified solid particles from the gasifier to the reactor comprises a) passing at least a second portion of the partially gasified solid particles from the gasifier to a coking section of the reactor; b) passing at least a second portion of the partially gasified solid particles from the gasifier to a stripping section of the reactor; or c) a combination of a) and b). 
     
     
         16 . The method of  claim 1 , wherein the gasifier comprises a single gasifier reactor. 
     
     
         17 . The method of  claim 1 , wherein the oxygen-containing gas comprises air, and wherein the gas phase product further comprises N 2  from the air. 
     
     
         18 . A system for performing fluidized coking, comprising:
 a fluidized bed coker comprising a reactor, a reactor coker feed inlet, a reactor cold coke outlet, a reactor hot coke inlet, a reactor liquid product outlet, and a fluidized bed of solid particles within the reactor, the fluidized bed of solid particles comprising a first portion of solid particles having potassium carbonate, calcium oxide, or a combination thereof supported on the first portion of solid particles; and   a gasifier comprising a gasifier coke inlet in fluid communication with the cold coke outlet, a gasifier coke outlet in fluid communication with the hot coke inlet, at least one gasifier input gas inlet, a fuel gas outlet, and a second portion of solid particles.   
     
     
         19 . The system of  claim 18 , wherein the first portion of solid particles comprises coke particles. 
     
     
         20 . The system of  claim 18 , wherein the second portion of solid particles comprises partially gasified coke particles. 
     
     
         21 . The system of  claim 18 , wherein the first portion of solid particles comprises potassium carbonate, calcium oxide, or a combination thereof supported on a refractory oxide support. 
     
     
         22 . The system of  claim 18 , wherein the reactor comprises a coking zone and a stripping zone, wherein a) the gasifier coke outlet is in fluid communication with the coking zone via the hot coke inlet, b) the gasifier coke outlet is in fluid communication with the stripping zone via the hot coke inlet, or c) a combination of a) and b). 
     
     
         23 . The system of  claim 18 , wherein the gasifier comprises a single gasifier reactor.