Processes and systems for converting a hydrocarbon-containing feed
Processes and systems for converting a hydrocarbon-containing feed. The feed and heated particles can be contacted within a pyrolysis zone to effect pyrolysis of at least a portion of the feed to produce a pyrolysis zone effluent and a first gaseous stream rich in olefins and a first particle stream rich in the particles can be obtained therefrom. At least a portion of the first particle stream, an oxidant, and steam can be fed into a gasification zone and contacted therein to effect gasification of at least a portion of coke disposed on the surface of the particles to produce a gasification zone effluent. A second gaseous stream rich in a synthesis gas and a second particle stream rich in heated and regenerated particles can be obtained from the gasification zone effluent. At least a portion of the second particle stream can be fed into the pyrolysis zone.
1 . A process for converting a hydrocarbon-containing feed by pyrolysis and gasification, comprising:
(I) feeding the hydrocarbon-containing feed and heated particles into a pyrolysis zone;
(II) contacting the hydrocarbon-containing feed with the heated particles in the pyrolysis zone to effect pyrolysis of at least a portion of the hydrocarbon-containing feed to produce a pyrolysis zone effluent comprising olefins and the particles, wherein coke is formed on the surface of the particles, and wherein a velocity of gaseous components within the pyrolysis zone is at least 20% greater than a velocity of the particles within the pyrolysis zone;
(III) obtaining from the pyrolysis zone effluent a first gaseous stream rich in the olefins and a first particle stream rich in the particles;
(IV) feeding at least a portion of the first particle stream, an oxidant stream, and a steam stream into a gasification zone;
(V) contacting the first particle stream, the oxidant stream, and the steam stream within the gasification zone to effect gasification of at least a portion of the coke disposed on the surface of the particles to produce a gasification zone effluent comprising heated and regenerated particles and a synthesis gas, wherein the synthesis gas comprises molecular hydrogen, carbon monoxide, and carbon dioxide;
(VI) obtaining from the gasification zone effluent a second gaseous stream rich in the synthesis gas and a second particle stream rich in the heated and regenerated particles; (VII) feeding at least a portion of the second particle stream into the pyrolysis zone as at least a portion of the heated particles fed into the pyrolysis zone in step (I);
(VIII) converting at least a portion of the carbon monoxide in the second gaseous stream and steam to carbon dioxide to produce a shifted synthesis gas stream; and
(IX) obtaining from the shifted synthesis gas stream a carbon dioxide lean synthesis gas stream and a carbon dioxide rich stream.
2 . The process of claim 1 , further comprising (X) separating the oxidant stream and a nitrogen stream from an air stream, wherein the oxidant stream comprises at least 40 vol % of molecular oxygen, and wherein the nitrogen stream comprises at least 60 vol % of molecular nitrogen.
3 . The process of claim 1 , further comprising (X) exposing at least a portion of the carbon dioxide lean synthesis gas stream to a methanol synthesis catalyst under methanol synthesis conditions to produce methanol.
4 . The process of claim 1 , further comprising (X) obtaining from the carbon dioxide lean synthesis gas stream a hydrogen rich stream and a nitrogen rich stream, wherein the hydrogen rich stream comprises at least 20 vol % of molecular hydrogen.
5 . The process of claim 1 , wherein a first portion of the coke on the surface of the particles is combusted within the gasification zone, and wherein a second portion of the coke on the surface of the particles and a portion of the steam are converted into molecular hydrogen and carbon monoxide within the gasification zone.
6 . The process of claim 1 , wherein step (IV) further comprises feeding a hydrocarbon fuel stream into the gasification zone, wherein a first portion of the hydrocarbon fuel stream is combusted within the gasification zone, and wherein a second portion of the hydrocarbon fuel stream is converted into molecular hydrogen and carbon monoxide.
7 . The process of claim 1 , wherein the synthesis gas further comprises molecular nitrogen, and wherein, on a volume basis, the synthesis gas comprises a greater amount of molecular hydrogen than molecular nitrogen.
8 . The process of claim 1 , wherein the second gaseous stream comprises 10 wt % to 25 wt % of molecular hydrogen, 15 wt % to 30 wt % of carbon monoxide, and at least 5 wt % of carbon dioxide, based on the total weight of the second gaseous stream.
9 . The process of claim 1 , wherein the oxidant stream comprises air or a fraction of air, and wherein, on a volume basis, a total amount of molecular oxygen to a total amount of molecular nitrogen within the gasification zone is at least 0.26:1.
10 . The process of claim 1 , further comprising feeding a steam stream into the pyrolysis zone in step (I), wherein:
a weight ratio of the steam stream to the hydrocarbon-containing feed fed into the within the pyrolysis zone is 0.01:1 to 6:1,
the pyrolysis zone is operated at a temperature of 800° C. to 1,100° C.,
a pressure within the pyrolysis zone is from 200 kPa-absolute to 1,000 kPa-absolute,
a velocity of the gaseous components within the pyrolysis zone is in a range of 9 m/s to 155 m/s,
a velocity of the particles within the pyrolysis zone is up to 15.5 m/s,
a weight ratio of the particles to the hydrocarbon-containing feed stream fed into the pyrolysis zone in step (I) is 10:1 to 50:1, and
the hydrocarbon-containing feed is contacted with the heated particles within the pyrolysis zone for a gas residence time of 10 milliseconds to 700 milliseconds.
11 . The process of claim 1 , wherein the heated particles fed into the pyrolysis zone in step (I) comprise an oxide of a transition metal element capable of oxidizing molecular hydrogen within the pyrolysis zone, and wherein at least a portion of the transition metal element in the particles in the first particle stream rich in the particles is at a reduced state compared to the transition metal element in the particles fed into the pyrolysis zone.
12 . The process of claim 1 , wherein the gasification zone is operated at a temperature of 1,050° C. to 1,500° C. and a pressure of 100 kPa-gauge to 1,000 kPa-gauge.
13 . The process of claim 1 , wherein the hydrocarbon containing feed has a total carbon content, and wherein about 10 wt % to about 45 wt % of the total carbon content is converted into carbon dioxide and utilized in an enhanced oil recovery process, sequestered, converted into another compound, or a combination thereof.
14 . The process of claim 1 , wherein a velocity of the gaseous components within the pyrolysis zone is in a range of 9 m/s to 155 m/s.
15 . The process of claim 1 , wherein the hydrocarbon-containing feed contacts the plurality of fluidized particles within the pyrolysis reaction zone for a residence time of 1 ms to 2,000 ms.
16 . The process of claim 1 , wherein the heated particles are at a temperature of 800° C. to 1,500° C. when fed into the pyrolysis zone.
17 . The process of claim 1 , wherein the pyrolysis zone is located in a downflow reactor, and wherein the pyrolysis zone effluent is recovered from a bottom of the downflow reactor and introduced into a separation stage to obtain the first gaseous stream rich in the olefins and the first particle stream rich in the particles.
18 . The process of claim 1 , further comprising, after step (VI) and before step (VIII), the following steps:
(VIb) indirectly transferring heat from the second gaseous stream to a cooling medium to produce a cooled second gaseous stream comprising water;
(VIc) separating at least a portion of the water and, if present, at least a portion of any regenerated particles and, if present, at least a portion of any hydrogen sulfide from the cooled second gaseous stream to produce a purified second gaseous stream; and
(VId) compressing at least a portion of the purified second gaseous stream to produce a compressed second gaseous stream, wherein in step (VIII) the at least a portion of the carbon monoxide in the compressed second gaseous stream is converted to carbon dioxide to produce the shifted synthesis gas stream.
19 . The process of claim 18 , wherein step (IV) further comprises feeding a diluent stream into the gasification zone, wherein the diluent stream comprises at least a portion of the second gaseous stream obtained in step (VI) or comprises at least a portion of the compressed second gaseous stream obtained in step (VId).
20 . The process of claim 1 , further comprising (X) exposing at least a portion of the carbon dioxide lean synthesis gas stream to an ammonia synthesis catalyst under ammonia synthesis conditions to produce ammonia.
21 . The process of claim 20 , further comprising (XI) exposing at least a portion of the ammonia and at least a portion of the carbon dioxide rich stream to reaction conditions sufficient to produce urea.
22 . A process for converting a hydrocarbon-containing feed by pyrolysis and gasification, comprising:
(I) feeding the hydrocarbon-containing feed and heated particles into a pyrolysis zone;
(II) contacting the hydrocarbon-containing feed with the heated particles in the pyrolysis zone to effect pyrolysis of at least a portion of the hydrocarbon-containing feed to produce a pyrolysis zone effluent comprising olefins and the particles, wherein coke is formed on the surface of the particles, and wherein a velocity of gaseous components within the pyrolysis zone is at least 20% greater than a velocity of the particles within the pyrolysis zone;
(III) obtaining from the pyrolysis zone effluent a first gaseous stream rich in the olefins and a first particle stream rich in the particles;
(IV) feeding at least a portion of the first particle stream, an oxidant stream, and a steam stream into a gasification zone;
(V) contacting the first particle stream, the oxidant stream, and the steam stream within the gasification zone to effect gasification of at least a portion of the coke disposed on the surface of the particles to produce a gasification zone effluent comprising heated and regenerated particles and a synthesis gas, wherein the synthesis gas comprises molecular hydrogen, carbon monoxide, and carbon dioxide;
(VI) obtaining from the gasification zone effluent a second gaseous stream rich in the synthesis gas and a second particle stream rich in the heated and regenerated particles, wherein the second gaseous stream comprises 10 wt % to 25 wt % of molecular hydrogen, 15 wt % to 30 wt % of carbon monoxide, and at least 5 wt % of carbon dioxide, based on the total weight of the second gaseous stream; and
(VII) feeding at least a portion of the second particle stream into the pyrolysis zone as at least a portion of the heated particles fed into the pyrolysis zone in step (I).
23 . The process of claim 22 , wherein the pyrolysis zone is located in a downflow reactor, and wherein the pyrolysis zone effluent is recovered from a bottom of the downflow reactor and introduced into a separation stage to obtain the first gaseous stream rich in the olefins and the first particle stream rich in the particles.