Catalytic hydrocarbon dehydrogenation

Patent metadata

Field	Value
Publication number	US-2021069683-A1
Application number	US-201916566801-A
Country	US
Kind code	A1
Filing date	Sep 10, 2019
Priority date	Sep 10, 2019
Publication date	Mar 11, 2021
Grant date	—

Abstract

A catalyst for dehydrogenation of hydrocarbons includes a support including zirconium oxide and Linde type L zeolite (L-zeolite). A concentration of the zirconium oxide in the catalyst is in a range of from 0.1 weight percent (wt. %) to 20 wt. %. The catalyst includes from 5 wt. % to 15 wt. % of an alkali metal or alkaline earth metal. The catalyst includes from 0.1 wt. % to 10 wt. % of tin. The catalyst includes from 0.1 wt. % to 8 wt. % of a platinum group metal. The alkali metal or alkaline earth metal, tin, and platinum group metal are disposed on the support.

First claim

1 . A catalyst for dehydrogenation of hydrocarbons, the catalyst comprising:
a support comprising zirconium oxide and Linde type L zeolite (L-zeolite), wherein a concentration of the zirconium oxide in the catalyst is in a range of from 0.1 weight percent (wt. %) to 20 wt. %; from 5 wt. % to 15 wt. % of an alkali metal or alkaline earth metal, the alkali metal or alkaline earth metal disposed on the support; from 0.1 wt. % to 10 wt. % of tin, the tin disposed on the support; and from 0.1 wt. % to 8 wt. % of a platinum group metal, the platinum group metal disposed on the support.

2 . The catalyst of claim 1 , wherein the alkali metal or alkaline earth metal is selected from the group consisting of lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, and barium.

3 . The catalyst of claim 2 , wherein the alkali metal is potassium or cesium.

4 . The catalyst of claim 2 , wherein the platinum group metal is selected from the group consisting of platinum, ruthenium, iridium, rhodium, and palladium.

5 . The catalyst of claim 2 , wherein the catalyst is configured to dehydrogenate hydrocarbons including 3 to 6 carbon atoms at an operating temperature in a range of from about 500 degrees Celsius (° C.) to about 800° C. and an operating pressure in a range of from about 0.01 bar to about 10 bar.

6 . The catalyst of claim 5 , wherein the catalyst is configured to dehydrogenate hydrocarbons including 3 to 6 carbon atoms in the presence of a diluent gas comprising hydrogen, steam, inert gas, or combinations thereof.

7 . The catalyst of claim 6 , wherein a concentration of hydrogen in the diluent gas is in a range of from 5 volume percent (vol. %) to 30 vol. %.

8 . A method of dehydrogenating hydrocarbons, the method comprising:
subjecting hydrocarbons to be dehydrogenated to an operating temperature in a range of from about 500 degrees Celsius (° C.) to about 800° C. within a reactor, wherein the hydrocarbons to be hydrogenated comprise n-pentane; subjecting the hydrocarbons to be dehydrogenated to an operating pressure in a range of from about 0.01 bar to about 10 bar within the reactor; while subjecting the hydrocarbons to be dehydrogenated to the operating temperature and operating pressure within the reactor, introducing a diluent gas to the hydrocarbons to be dehydrogenated, the diluent gas comprising hydrogen and inert gas; and using a catalyst disposed within the reactor to dehydrogenate the hydrocarbons to be dehydrogenated in the presence of the diluent gas within the reactor, the catalyst comprising:
a support comprising zirconium oxide and L-zeolite, wherein a concentration of the zirconium oxide in the catalyst is in a range of from 0.1 weight percent (wt. %) to 20 wt. %;
from 5 wt. % to 15 wt. % of an alkali metal or alkaline earth metal, the alkali metal or alkaline earth metal disposed on the support;
from 0.1 wt. % to 10 wt. % of tin, the tin disposed on the support; and
from 0.1 wt. % to 8 wt. % of a platinum group metal, the platinum group metal disposed on the support, wherein the catalyst forms catalyst grains of about 200 micrometers (μm) to about 500 μm in size.

9 . The method of claim 8 , wherein the alkali metal or alkaline earth metal is selected from the group consisting of lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, and barium.

10 . The method of claim 9 , wherein the alkali metal is potassium or cesium.

11 . The method of claim 9 , wherein a ratio of hydrogen to inert gas in the diluent gas is in a range of from 11:70 to 71:10.

12 . The method of claim 9 , further comprising, before using the catalyst to dehydrogenate the hydrocarbons to be dehydrogenated, activating the catalyst, wherein activating the catalyst comprises:
placing the catalyst grains within the reactor; flowing a stream comprising oxygen to the catalyst grains within the reactor; while flowing the stream comprising oxygen to the catalyst grains, increasing a temperature within the reactor to 450° C.; after the temperature within the reactor reaches 450° C., flowing a stream comprising an inert gas to the catalyst grains within the reactor; while flowing the stream comprising the inert gas to the catalyst grains, decreasing the temperature within the reactor to 400° C.; after the temperature within the reactor reaches 400° C., flowing a stream comprising hydrogen to the catalyst grains within the reactor; and adjusting the temperature within the reactor to the operating temperature.

13 . A method of preparing a catalyst for dehydrogenation of hydrocarbons, the method comprising:
mixing a Linde type L zeolite (L-zeolite) with an aqueous solution of a first additive to form a first slurry, the first additive comprising a salt or complex comprising zirconium; drying the first slurry in the presence of oxygen to form a first solid; mixing the first solid with an aqueous solution of a second additive to form a second slurry, the second additive comprising a salt comprising an alkali metal or an alkaline earth metal; drying the second slurry to form a second solid; mixing the second solid with an ethanolic solution of a third additive to form a third slurry, the third additive comprising a salt or complex comprising tin; drying the third slurry to form a third solid; mixing the third solid with an aqueous solution of a fourth additive to form a fourth slurry, the fourth additive comprising a salt or complex comprising a platinum group metal; drying the fourth slurry in the presence of oxygen to form the catalyst having a composition comprising: from 0.1 weight percent (wt. %) to 20 wt. % of zirconium derived from the first additive; from 5 wt. % to 15 wt. % of the alkali metal or alkaline earth metal derived from the second additive; from 0.1 wt. % to 10 wt. % of the tin derived from the third additive; from 0.1 wt. % to 8 wt. % of the platinum group metal derived from the fourth additive; and a balance of L-zeolite.

14 . The method of claim 13 , wherein the first additive is selected from the group consisting of zirconium oxynitrate, zirconium oxychloride, zirconium acetate, and zirconium acetylacetonate.

15 . The method of claim 13 , wherein an anionic portion of the salt in the second additive is selected from the group consisting of nitrate ion, nitrite ion, sulfate ion, hydroxide ion, and halide ion.

16 . The method of claim 13 , wherein the third additive is selected from the group consisting of tin(II) chloride dehydrate, tin(IV) chloride hydrate, and tin(IV) bis(acetylacetonate).

17 . The method of claim 13 , wherein the fourth additive is selected from the group consisting of dihydrogen hexachloroplatinate hexahydrate, tetraammineplatinum dihydroxide, tetraammineplatinum dinitrate, and tetraammineplatinum dichloride.

18 . The method of claim 13 , further comprising, before mixing the L-zeolite with the aqueous solution of the first additive, treating the L-zeolite such that a Brunauer-Emmett-Teller (BET) surface area of the L-zeolite is at least 200 square meters per gram, wherein treating the L-zeolite comprises:
heating the L-zeolite to a first temperature in the presence of oxygen; maintaining the L-zeolite at the first temperature in the presence of oxygen for a first time duration; heating the L-zeolite to a second temperature in the presence of oxygen, wherein the second temperature is greater than the first temperature; and maintaining the L-zeolite at the second temperature in the presence of oxygen for a second time duration.

Assignees

• Saudi Arabian Oil Co

Inventors

• Al-Daous Mohammed Abdulmajeed
• Bahlouli Hussam A

Classifications

• B01J23/626 Primary

  with tin · CPC title

• C07C2529/62

  Noble metals · CPC title

• C07C2521/06

  Silicon, titanium, zirconium or hafnium; Oxides or hydroxides thereof · CPC title

• C07C5/3337

  of the platinum group · CPC title

• C07C2529/06

  Crystalline aluminosilicate zeolites; Isomorphous compounds thereof · CPC title