1. A process comprising:
(a) introducing a feed stream comprising para-xylene into a reaction zone of a bubble column reactor;
(b) introducing one or more oxidant streams comprising molecular oxygen into said reaction zone, wherein said reaction zone has a maximum diameter (D), wherein a majority of said molecular oxygen enters said reaction zone within about 0.25 D of the bottom of said reaction zone; and
(c) oxidizing at least a portion of said para-xylene in a liquid phase of a three-phase reaction medium contained in said reaction zone, wherein said oxidizing causes at least a portion of said para-xylene to form solid crude terephthalic particles in said reaction medium
wherein each of said one or more oxidant streams introduced into the reaction zone has oxygen present in an amount ranging from 5 mole % to 40 mole % and wherein said reaction medium comprises in the range of from about 5 to about 40 weight percent solids on a time-averaged and volume-averaged basis.
2. The process of claim 1 wherein said reaction medium has a maximum height (H), wherein a majority of said molecular oxygen enters said reaction zone within about 0.025 H of the bottom of said reaction zone.
3. The process of claim 2 wherein a majority of said molecular oxygen enters said reaction zone within about 0.2 D and about 0.02 H of the bottom of said reaction zone.
4. The process of claim 2 wherein a majority of said molecular oxygen enters said reaction zone within 0.15 D and 0.015 H of the bottom of said reaction zone.
5. The process of claim 1 wherein said process further comprises deaerating a portion of said reaction medium in a deaeration zone separate from said reaction zone thereby providing a substantially deaerated slurry comprising less than 5 volume percent gas, wherein said deaerating is caused primarily by the natural buoyancy of the gas phase of said three-phase reaction medium in the solid and liquid phases of said three-phase reaction medium.
6. The process of claim 5 wherein said deaeration zone is defined between one or more upright sidewalls of a deaeration vessel, wherein the maximum horizontal cross-sectional area of said deaeration zone is less than 25 percent of the maximum horizontal cross-sectional area of said reaction zone.
7. The process of claim 1 wherein said reaction medium has a maximum height (H), a maximum width (W), and an H:W ratio of at least about 3:1.
8. The process of claim 1 wherein at least about 30 weight percent of said para-xylene enters said reaction zone within about 1.5 D of the lowest location where said molecular oxygen enters said reaction zone.
9. The process of claim 1 wherein said feed stream is introduced into said reaction zone via a plurality of feed openings, wherein at least two of said feed openings are vertically spaced from one another by at least about 0.5 D.
10. The process of claim 1 wherein said oxidizing is carried out in a manner such that when the entire volume of said reaction medium is theoretically partitioned into 2,000 discrete horizontal slices of equal volume, less than 40 of said horizontal slices have a gas hold-up less than 0.3 on a time-averaged and volume-averaged basis.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A process, comprising:
injecting feedstock material into a gasification chamber;
gasifying the feedstock material in the gasification chamber at a first temperature and a first pressure in a range of about 25 psi to about 100 psi, and producing a first volume of gas and a first amount of by-product material;
injecting at least a portion of the first amount of by-product material into a solids reactor; and
gasifying at least the portion of the first amount of by-product material in the solids reactor at a second temperature and a second pressure in a range of about 25 psi to about 100 psi, and producing a second volume of gas and a second amount of by-product material.
2. The process of claim 1, wherein injecting the feedstock material into the gasification chamber includes injecting a volume of steam into the gasification chamber, wherein the volume of steam is superheated at a temperature of at least about 1200\xb0 F.
3. The process of claim 1, wherein injecting the feedstock material into the gasification chamber includes mixing the feedstock material with water, wherein mixture of water with the feedstock material has a water-to-solid ratio that ranges from about 1 to about 1.5, a value of the water-to-solid ratio is based at least on amount of carbon present in the feedstock material.
4. The process of claim 1, wherein gasifying the feedstock material in the gasification chamber at the first temperature includes heating a metal drum that resides within the gasification chamber to substantially the first temperature, where the first temperature is in the range of about 1000\xb0 F. to about 1750\xb0 F.
5. The process of claim 1, wherein gasifying at least the portion of the first amount of by-product material in the solids reactor at the second temperature includes heating a single metal drum that resides within the solids reactor to substantially the second temperature, where the second temperature is at most about 1750\xb0 F.
6. The process of claim 1, further comprising: disposing at least a fraction of the second amount of by-product material.
7. The process of claim 1, further comprising:
reacting at least a part of the first volume of gas and at least a part of the second volume of gas with steam and producing a flow of reacted synthesis gas, wherein gas in the first volume of gas is pyrolysis gas, and gas in the second volume of gas is substantially synthesis gas; and
cleaning the flow of reacted synthesis gas.
8. The process of claim 1, further comprising:
reacting at least a part of the first volume of gas with steam and producing a flow of reacted synthesis gas, wherein gas in the first volume of gas is pyrolysis gas;
cleaning the flow of reacted synthesis gas; and
cleaning at least a part of the second volume of gas, wherein gas in the second volume of gas is substantially synthesis gas.
9. The process of claim 1, wherein injecting at least the portion of the first amount of by-product material into the solids reactor includes injecting a volume of steam into the solids reactor, wherein the volume of steam is superheated at a temperature of at least about 1200\xb0 F.
10. The process of claim 7, wherein the cleaning includes circulating the flow of reacted synthesis gas through a scrubbing apparatus.
11. The process of claim 7, wherein the cleaning includes circulating the flow of reacted synthesis gas through at least one cyclone and a scrubbing apparatus.
12. The process of claim 8, wherein cleaning at least the part of the second volume of gas includes collecting the second volume of gas directly from the solids reactor.
13. The process of claim 12, wherein collecting the second volume of gas directly from the solids reactor includes:
analyzing a chemical composition of the second volume of gas; and
based at least on the chemical composition, bypassing a steam reformation reactor, wherein the steam reformation reactor comprises a set of metal coils heated to a temperature equal to or above about the first temperature.
14. A system, comprising:
a pyrolysis chamber comprising a vessel coated in its interior with a refractory material, and a first metal drum that houses an amount of feedstock material at a first pressure in the range of about 25 psi to about 100 psi and rotates about an axis of substantial cylindrical symmetry of the first metal drum; and
a solids reactor operationally coupled to the pyrolysis chamber, the solids reactor receives an amount of feedstock by-product from the pyrolysis chamber and houses the amount of feedstock by-product in a second metal drum at a second pressure in the range of about 25 psi to about 100 psi.
15. The system of claim 14, further comprising:
a steam reformation reactor that collects (i) gas generated through gasification of at least one of the amount of feedstock material within the pyrolysis chamber or the amount of feedstock by-product within the solids reactor, and (ii) reacts the gas with superheated steam.
16. The system of claim 15, further comprising:
an accumulation vessel that receives the amount of feedstock material and pressurizes the amount of feedstock material to the first pressure;
an accumulation chamber that collects the amount of feedstock material at the first pressure and injects the amount of feedstock material into the pyrolysis chamber.
17. The system of claim 14, wherein the amount of feedstock material is housed at a first temperature in the range of about 1000\xb0 F. to about 1750\xb0 F., and the amount of feedstock by-product is housed at a second temperature of at most about 1750\xb0 F.
18. The system of claim 14, wherein the first metal drum that houses the amount of feedstock material for a time interval in the range of about 10 minutes to about 36 minutes.
19. The system of claim 14, wherein the second metal drum houses the amount of feedstock by-product for a time-interval in a range of about 3 minutes to about 20 minutes.
20. The system of claim 17, wherein the pyrolysis chamber includes at least one heating element that heats the first metal drum to the first temperature.
21. The system of claim 17, wherein the solids reactor includes at least one heating element that heats the second metal drum to the second temperature.
22. The system of claim 15, wherein the gas within the steam reformation reactor reacts with the superheated steam for a time interval shorter than about 10 seconds.
23. The system of claim 22, wherein reacted gas is ejected from the steam reformation reactor at a temperature of at least about 1000\xb0 F., the reacted gas is synthesis gas.
24. The system of claim 23, wherein the reacted gas is ejected to a cleaning platform where the reacted gas is cleaned of particulate matter, impurities, or a combination thereof, wherein the cleaning platform includes at least one of a cyclone or a scrubbing apparatus.
25. The system of claim 14, wherein the pyrolysis chamber includes a motor that rotates the first metal drum at a predetermined angular velocity.
26. The system of claim 14, wherein the solids reactor includes a motor that rotates the second metal drum at a predetermined angular velocity.
27. An apparatus, comprising:
means for gasifying the feedstock material in a plurality of gasification chambers at a first temperature and a first pressure in the range of about 25 psi to about 100 psi, and producing a first volume of gas and a first amount of by-product material; and
means for injecting at least a portion of the first amount of by-product material into one or more solids reactors functionally coupled to the plurality of gasification chambers
28. The apparatus of claim 27, further comprising:
means for gasifying at least the portion of the first amount of by-product material in the one or more solids reactors at a second temperature and a second pressure in the range of about 25 psi to about 100 psi, and producing a second volume of gas and a second amount of by-product material.
29. The apparatus of claim 27, wherein the means for gasifying the feedstock material in the gasification chamber at the first temperature includes means for heating a metal drum that resides within the gasification chamber to substantially the first temperature, where the first temperature is in the range of about 1000\xb0 F. to about 1750\xb0 F.
30. The apparatus of claim 27, wherein the means for gasifying at least the portion of the first amount of by-product material in the one or more solids reactors at the second temperature includes means for heating to substantially the second temperature at least one metal drum that resides within a respective solids reactor in the one or more solids reactors, the second temperature is at most about 1750\xb0 F.
31. The apparatus of claim 27, further comprising:
means for reacting with superheated steam at least one of the first volume of gas or the second volume of gas, wherein gas in the first volume of gas is pyrolysis gas and gas in the second volume of gas is substantially synthesis gas.
32. The apparatus of claim 30, further comprising:
means for cleaning one or more of the first volume of gas or the second volume of gas.