Hydrocarbon pyrolysis

Patent metadata

Field	Value
Publication number	US-10711203-B2
Application number	US-201716320136-A
Country	US
Kind code	B2
Filing date	Aug 15, 2017
Priority date	Aug 31, 2016
Publication date	Jul 14, 2020
Grant date	Jul 14, 2020

Abstract

The invention relates to hydrocarbon pyrolysis, to equipment and materials useful for hydrocarbon pyrolysis, to processes for carrying out hydrocarbon pyrolysis, and to the use of hydrocarbon pyrolysis for, e.g., hydrocarbon gas upgrading. The pyrolysis is carried out in a reactor which includes at least one thermal mass having an open frontal area ≤55%.

First claim

The invention claimed is:

1. A hydrocarbon pyrolysis process, the process comprising:
(a) providing a feed comprising ≥1 wt. % of C 2+ hydrocarbon;
(b) providing an elongated flow-through reactor having (i) an internal volume which includes first and second regions, opposed first and second openings in fluidic communication with the internal volume, wherein the first and second openings are separated by a reactor length (L R ), and (ii) a first channeled thermal mass located in the first region, the first channeled thermal mass having an open frontal area ≤55% and comprising a refractory, wherein the first channeled thermal mass includes:
(A) a first aperture, the first aperture being proximate to the first opening and in fluidic communication with the first opening,
(B) at least one internal channel in fluidic communication with the first aperture, and
(C) a second aperture, the second aperture being in fluidic communication with the first aperture via a flowpath L 1 through the channel, L 1 being ≥0.1*L R ;

(c) heating the first channeled thermal mass;
(d) establishing a flow of the feed into the channel toward the second aperture at a flow rate ≥0.01 kg/s by introducing the feed through the first opening and through the first aperture;
(e) pyrolysing the feed flow's C 2+ hydrocarbon in the channel under pyrolysis conditions during a pyrolysis time interval t P of at least one second which begins at a first time t 1 and ends at a second time t 2 which cools the first channeled thermal mass and produces a flow of a pyrolysis product comprising molecular hydrogen and C 2+ olefin, wherein the pyrolysis conditions include:
(i) a conversion ≥50 wt. %,
(ii) a first gas temperature profile at t 1 which increases substantially monotonically from a first temperature (T 1 ) proximate to the first aperture to a second temperature (T 2 ) proximate to the second aperture, with T 2 being in the range of from 800° C. to 1400° C., and
(iii) a second gas temperature profile at t 2 which exhibits a temperature T 3 proximate to the first aperture and a temperature T 4 proximate to the second aperture, wherein T 3 is ≤T 1 and T 4 is in the range of from T 2 to (T 2 −100° C.); and

(f) during t P , conducting the flow of the pyrolysis product into the second region of the internal volume via the second aperture, and away from the reactor via the second opening.

2. A hydrocarbon pyrolysis process, the process comprising:
(a) providing a feed comprising ≥1 wt. % of C 2+ hydrocarbon;
(b) providing an elongated flow-through reactor having (i) an internal volume which includes first and second regions, opposed first and second openings in fluidic communication with the internal volume, wherein the first and second openings are separated by a reactor length (L R ), and (ii) a first channeled thermal mass located in the first region, the first channeled thermal mass having an open frontal area ≤55% and comprising a refractory, wherein the first channeled thermal mass includes:
(A) a first aperture, the first aperture being proximate to the first opening and in fluidic communication with the first opening,
(B) at least one internal channel in fluidic communication with the first aperture, and
(C) a second aperture, the second aperture being in fluidic communication with the first aperture via a flowpath L 1 through the channel, L 1 being ≥0.1*L R ;

(c) heating the first channeled thermal mass;
(d) establishing a flow of the feed into the channel toward the second aperture at a flow rate ≥0.01 kg/s toward the second aperture by introducing the feed through the first opening and through the first aperture;
(e) pyrolysing the feed flow's C 2+ hydrocarbon in the channel under pyrolysis conditions during a pyrolysis time interval t P of at least one second which begins at a first time t 1 and ends at a second time t 2 which cools the first thermal mass and produces a flow of a pyrolysis product comprising molecular hydrogen, and C 2+ olefin, the pyrolysis conditions including:
(i) a conversion ≥50 wt. %,
(ii) a peak gas temperature T p located within the reactor, the peak gas temperature being positioned along L 1 ,
(iii) a first bulk gas temperature profile at t 1 which varies continuously along L 1 from a first temperature (T 1 ) proximate to the first aperture to a second temperature (T 2 ) proximate to the second aperture, wherein T 1 <T 2 , T 2 <T p , and T 2 is in the range of from 800° C. to 1400° C.,
(iv) a second gas temperature profile at t 2 which exhibits a temperature T 3 proximate to the first aperture and T 4 proximate to the second aperture, wherein T 3 is ≤T 1 and T 4 is <T 2 , and
(v) during t P , T p decreases by an amount that does not exceed 100° C. and the position of T p along L 1 remains substantially constant; and

(f) during t P , conducting the flow of the pyrolysis product into the second region of the internal volume via the second aperture, and away from the reactor via the second opening.

3. The process of claim 1 , wherein (i) the reactor has a peak gas temperature T p within the internal volume, (ii) T p is located in the second region, T p is >T 2 at t 1 , T p decreases during t P , (iii) the location of T p remains substantially constant during t P , (iv) the pyrolysis conditions further include a hydrocarbon partial pressure of ≥7 psia (48 kPa) and a total pressure of ≥5 psig (34 kPag), and (v) t P is ≥2 seconds.

4. The process of claim 1 , wherein (i) the reactor is a reverse-flow thermal pyrolysis reactor, the reactor further comprising a second thermal mass located in the second region of the internal volume, the second thermal mass having at least one internal channel having at least one in fluidic communication with the internal channel of the first thermal mass, and (ii) the process further comprises (f) conducting the pyrolysis product through the internal channel of the second thermal mass before the pyrolysis product is conducted away from the reverse-flow reactor, and (g) cooling the pyrolysis product by transferring heat from the pyrolysis product to the second thermal mass.

5. The process of claim 1 , wherein (i) the C 2+ olefin includes one or more of ethylene, propylene, and butylene, (ii) the pyrolysis product further comprises coke and one or more of acetylene, benzene, methane, and at least a portion of any unconverted feed, and (iii) at least a portion of the coke remains in the internal channel of the first thermal mass as a deposit.

6. The process of claim 1 , wherein the feed comprises one or more of ethane, propane, butanes, saturated and unsaturated C 6 hydrocarbon, including those derived from one or more of Fischer-Tropsch synthesis products, shale gas, biogas, associated gas, natural gas and mixtures or components thereof, steam cracked gas oil and residues, gas oils, heating oil, jet fuel, diesel, kerosene, gasoline, naphtha (including coker naphtha, steam cracked naphtha, and catalytically cracked naphtha), hydrocrackate, reformate, raffinate reformate, Fischer-Tropsch liquids, natural gasoline, distillate, virgin naphtha, crude oil, atmospheric pipestill bottoms, vacuum pipestill streams including bottoms, wide boiling range naphtha to gas oil condensates, heavy non-virgin hydrocarbon streams from refineries, vacuum gas oils, heavy gas oil, naphtha contaminated with crude, synthetic crudes, shale oils, coal liquefaction products, coal tars, tars, atmospheric resid, heavy residuum, C 4 -residue admixture, naphtha-residue admixture, cracked feed, coker distillate streams, and hydrocarbon streams derived from plant or animal matter.

7. The process of claim 1 , wherein the feed comprises ≥90 wt. % of (i) ethane and/or (ii) propane, and the conversion is ≥60 wt. %.

Assignees

• Exxonmobil Chemical Patents Inc

Inventors

• Barrai Federico
• Mahoney Elizabeth G
• Coleman John S
• Bhandari Dhaval A
• Weiss Brian M
• Chun Changmin
• Hershkowitz Frank

Classifications

• C10G9/26 Primary

  with discontinuously preheated non-moving solid material, e.g. blast and run · CPC title

• C10G9/203

  chemical composition of the tubes · CPC title

• C10G9/206

  controlling or regulating the tube furnaces · CPC title