Deydrogenative Coupling of Low-Value Light Alkanes to Sustainable Aviation Fuel
A dehydrogenative coupling process to convert alkanes to longer chain olefins in a single process step is described. The approach described combats the thermodynamics of traditional dehydrogenation by consuming the products as they form. This dehydrogenative coupling reaction may be performed in a single reactor which could enable increased per-pass yield of desirable C 8+ olefins compared to a traditional two reactors in a series.
1 . A method comprising:
forming a mixed bed comprising a dehydrogenation catalyst and a coupling catalyst; and
applying a feed stream to the mixed bed; wherein:
the applying results in a molecular weight hydrocarbon.
2 . The method of claim 1 , wherein:
the dehydrogenation catalyst comprises:
at least one of Pt—Sn/Al 2 O 3 or a zeolite material, wherein:
the Pt—Sn/Al 2 O 3 or the zeolite material is modified with at least one of vanadium (V), zinc (Zn), copper (Cu), gallium (Ga), nickel (Ni), or platinum (Pt).
3 . The method of claim 1 , wherein:
the dehydrogenation catalyst comprises an amorphous silica-alumina material modified with at least one of V, Zn, Cu, Ga, Ni, or Pt.
4 . The method of claim 1 , wherein:
the coupling catalyst comprises a BEA zeolite.
5 . The method of claim 4 , wherein:
the BEA zeolite has a silica-alumina ratio (SAR) in the range of 10 to 300.
6 . The method of claim 4 , wherein:
the BEA zeolite has a silicoaluminophosphate zeotype (SAPO).
7 . The method of claim 4 , wherein:
the BEA zeolite comprises a mixed oxide of at least one of WO 3 —ZrO 2 , SiO 2 —AlO 3 , or phosphated—SiO 2 —AlO 3 .
8 . The method of claim 1 , wherein:
the coupling catalyst comprises a faujasite (FAU) zeolite.
9 . The method of claim 8 , wherein:
the FAU zeolite has a silica-alumina ratio (SAR) in the range of 10 to 300.
10 . The method of claim 8 , wherein:
the FAU zeolite has a silicoaluminophosphate zeotype (SAPO).
11 . The method of claim 8 , wherein:
the FAU zeolite comprises a mixed oxide of at least one of WO 3 —ZrO 2 , SiO 2 —AlO 3 , or phosphated—SiO 2 —AlO 3 .
12 . The method of claim 1 , wherein:
the feed stream comprises at least one C4-C8 branched hydrocarbon.
13 . The method of claim 1 , wherein:
the feed stream comprises isobutane, argon, and nitrogen.
14 . The method of claim 13 , wherein:
the feed stream further comprises a hydrogen gas (H 2 ).
15 . The method of claim 1 , wherein:
the applying is performed at a temperature greater than approximately 300° C.
16 . The method of claim 1 , wherein:
the applying is performed at a temperature in the range of approximately 300° C. to approximately 500° C.
17 . The method of claim 1 , wherein:
the applying is performed at a pressure in the range from about 1 psig to about 150 psig.
18 . The method of claim 17 , wherein:
the applying is performed at a pressure of greater than about 50 psig.
19 . The method of claim 1 , wherein:
the higher molecular weight hydrocarbon comprises a C 8+ hydrocarbon.
20 . The method of claim 19 , wherein:
the C 5+ hydrocarbon comprises octane, nonane, decane, undecane, dodecane, octene, nonene, decene, undecene, dodecene, octyne, nonyne, decyne, undecyne, dodecyne, cyclooctane, cyclononane, cyclodecane, cycloundecane, cyclododecane, octadiene, nonadiene, decadiene, undecadiene, or dodecadiene.