Integration of side riser for aromatization of light paraffins

Abstract

Systems and methods are provided for conversion of light paraffinic gases to form liquid products in a two-stage reaction system. In a first stage, the light paraffinic gas is exposed to heat transfer particles in a side riser, where the heat transfer particles correspond to particles used in a separate process. Examples of a separate process include fluidized coking and fluid catalytic cracking. The conditions in the side riser can be selected to allow for conversion of at least a portion of the paraffins to olefins. After conversion, the converted olefin stream is passed to the second reaction stage while the heat transfer particles are returned to the separate process. The converted olefin stream is then exposed to a conversion catalyst under conditions for forming aromatics from the converted olefin stream in a second reaction stage. By performing the initial alkane conversion to olefins in the first reaction stage, the amount of coke formed during the aromatics formation process is reduced or minimized.

1 . A method for processing a paraffin-containing feed, comprising:
 passing a first portion of heat transfer particles from a burner of a reaction system to a reactor of the reaction system;   passing a second portion of heat transfer particles from the burner to a side riser;   exposing a feed comprising C 3+  paraffins to the second portion of heat transfer particles in the side riser under paraffin to olefin conversion conditions to form a side riser effluent comprising heat transfer particles including deposited coke and a gas phase effluent;   separating a third portion of the heat transfer particles including deposited coke from the gas phase effluent;   exposing at least a portion of the gas phase effluent to one or more beds of a conversion catalyst to form an aromatic formation effluent comprising C 6 -C 12  aromatics;   passing the third portion of the heat transfer particles into the reaction system;   exposing a second feedstock to the first portion of heat transfer particles and the third portion of the heat transfer particles in the reactor under first processing conditions to form a first reactor effluent comprising heat transfer particles including additional coke;   separating at least a portion of the heat transfer particles including additional coke from the first reactor effluent; and   passing the separated heat transfer particles into the burner.   
     
     
         2 . The method of  claim 1 , wherein the reactor comprises a fluidized coking reactor, the first processing conditions comprise fluidized coking conditions, and the heat transfer particles comprise coke particles. 
     
     
         3 . The method of  claim 2 , wherein passing the third portion of the heat transfer particles into the reaction system comprises passing the third portion of the heat transfer particles into the reactor; or wherein passing the third portion of the heat transfer particles into the reaction system comprises passing the third portion of the heat transfer particles into the burner; or a combination thereof. 
     
     
         4 . The method of  claim 2 , wherein the burner comprises a gasifier. 
     
     
         5 . The method of  claim 4 , wherein transferring the first portion of heat transfer particles from the burner to the reactor comprises transferring the first portion of heat transfer particles to a heater of the reaction system, and transferring the first portion of heat transfer particles from the heater to the reactor. 
     
     
         6 . The method of  claim 4 , wherein passing the separated heat transfer particles into the burner comprises passing the separated heat transfer particles into a heater of the reaction system, and transferring the separated heat transfer particles from the heater to the burner. 
     
     
         7 . The method of  claim 4 , wherein passing the third portion of the heat transfer particles into the reaction system comprises passing the third portion of the heat transfer particles into a heater of the reaction system. 
     
     
         8 . The method of  claim 1 , wherein the reactor comprises a fluid catalytic cracking (FCC) reactor, the first processing conditions comprise FCC processing conditions, the burner comprises a regenerator, and the heat transfer particles comprise FCC catalyst particles. 
     
     
         9 . The method of  claim 8 , wherein the reaction system further comprises a catalyst cooler. 
     
     
         10 . The method of  claim 1 , wherein the one or more beds of the conversion catalyst comprise moving catalyst beds of conversion catalyst in a moving bed reactor; or wherein the one or more beds of the conversion catalyst comprise fixed beds of conversion catalyst in one or more radial flow reactors, one or more axial flow reactors, or a combination thereof. 
     
     
         11 . The method of  claim 1 , wherein the feed comprises 30 vol % to 70 vol % C 3+  paraffins, or wherein the feed comprises 30 vol % to 70 vol % C 3 -C 4  paraffins, or wherein the feed comprises 30 vol % to 70 vol % C 3 -C 6  paraffins. 
     
     
         12 . The method of  claim 1 , wherein the feed further comprises methane, ethane, or a combination thereof. 
     
     
         13 . The method of  claim 1 , wherein the at least a portion of the gas phase effluent is exposed to the conversion catalyst at a temperature of about 450° C. to about 650° C., a pressure in the one or more beds of conversion catalyst comprising at least about 200 kPa-a, and a WHSV of about 0.1 hr −1  to about 4.0 hr −1 . 
     
     
         14 . The method of  claim 1 , the method further comprising heating an intermediate aromatic formation effluent formed by exposure of the at least a portion of the gas phase effluent to a first catalyst bed of the one or more beds of conversion catalyst, the heating of the intermediate aromatic effluent being prior to exposure of the intermediate aromatic formation effluent to a second catalyst bed of the one or more beds of conversion catalyst. 
     
     
         15 . The method of  claim 1 , wherein the conversion catalyst comprises ZSM-5, ZSM-11, ZSM-12, ZSM-22, ZSM-23, ZSM-35, ZSM-48, MCM-22, MCM-49, or a combination thereof. 
     
     
         16 . The method of  claim 1 , wherein the conversion catalyst comprises 0.1 wt % to 5.0 wt % of a metal from Groups 3-13 of the periodic table relative to a weight of the catalyst particles, the metal optionally comprising Ga, In, or a combination thereof. 
     
     
         17 . A method for processing a paraffin-containing feed, comprising:
 passing a first portion of coke particles from a gasifier of a fluidized coking system, a heater of a fluidized coking system, or a combination thereof to a reactor of the fluidized coking system;   passing a second portion of coke particles from the gasifier, the heater, or a combination thereof to a side riser;   exposing a feed comprising C 3+  paraffins to the second portion of coke particles in the side riser under paraffin to olefin conversion conditions to form a side riser effluent comprising coke particles including deposited coke and a gas phase effluent;   separating a third portion of the coke particles including deposited coke from the gas phase effluent;   exposing at least a portion of the gas phase effluent to one or more beds of a conversion catalyst to form an aromatic formation effluent comprising C 6 -C 12  aromatics;   passing the third portion of the coke particles into the fluidized coking reactor;   exposing a fluidized coking feedstock to the first portion of coke particles and the third portion of the coke particles in the reactor under fluidized coking conditions to form a coker effluent comprising coke particles including additional coke;   separating at least a portion of the coke particles including additional coke from the coker effluent; and   passing the separated coker particles into the gasifier.   
     
     
         18 . A reaction system for conversion of paraffins to aromatics, comprising:
 a first reaction system comprising a reactor and a burner, the reactor being in fluid communication with the burner for transfer of heat transfer particles;   a side riser comprising one or more side riser inlets and a side riser outlet, the one or more side riser inlets being in fluid communication with a feed source and in fluid communication with the burner for transfer of heat transfer particles;   a separation stage comprising a separation stage inlet, a separation stage solids outlet, and a separation stage gas outlet, the separation stage inlet being in fluid communication with the side riser outlet, the separation stage solids outlet being in fluid communication with the first reactor; and   a second reaction system comprising one or more beds of conversion catalyst, the second reaction system being in fluid communication with the separation stage gas outlet,   wherein the conversion catalyst comprises a) 0.1 wt % to 5.0 wt % of a metal from Groups 3-13 of the periodic table relative to a weight of the conversion catalyst, the metal optionally comprising Ga, In, or a combination thereof, and b) ZSM-5, ZSM-11, ZSM-12, ZSM-22, ZSM-23, ZSM-35, ZSM-48, MCM-22, MCM-49, or a combination thereof.   
     
     
         19 . The reaction system of  claim 18 , wherein the one or more beds of conversion catalyst comprise moving beds of conversion catalyst in one or more moving bed reactors; or wherein the second reaction system comprises one or more fixed bed radial flow reactors comprising the one or more beds of conversion catalyst, one or more fixed axial flow reactors comprising the one or more beds of conversion catalyst, or a combination thereof. 
     
     
         20 . The reaction system of  claim 18 , wherein the reactor comprises a fluidized coking reactor, the burner comprises a gasifier, and the heat transfer particles comprise coke particles. 
     
     
         21 . The reaction system of  claim 20 , wherein the first reaction system further comprises a heater, wherein at least a portion of the fluid communication between the fluidized coking reactor and the gasifier comprises indirect fluid communication via the heater. 
     
     
         22 . The reaction system of  claim 18 , wherein the reactor comprises a fluid catalytic cracking reactor and the burner comprises a regenerator; or wherein the reaction system further comprises a catalyst cooler; or a combination thereof.