Dehydrogenation process at reduced hydrogen to hydrocarbon ratios

Patent metadata

Field	Value
Publication number	US-10647636-B2
Application number	US-201816178260-A
Country	US
Kind code	B2
Filing date	Nov 1, 2018
Priority date	Nov 2, 2017
Publication date	May 12, 2020
Grant date	May 12, 2020

Abstract

Processes for dehydrogenation of a hydrocarbon feedstock are described. The process can be run at lower H2/HC ratios and lower RITs while maintaining coke production at the same level as operation at higher H2/HC ratios and higher RITs without decreasing the yield per pass. Acceptable levels of coke were achieved when operating the process at low hydrogen to hydrocarbon molar ratio in the range of 0.01 to 0.40 and reactor inlet temperatures in the range of 500°-645° C. The process uses a low coke catalyst.

First claim

What is claimed is:

1. A process for dehydrogenation of a hydrocarbon feedstock, the process comprising:
passing a feed stream comprising hydrogen and paraffins into a dehydrogenation zone comprising at least one reactor containing a dehydrogenation catalyst maintained at dehydrogenation conditions to produce a dehydrogenation zone product stream comprising hydrogen, paraffins, and olefins, wherein the dehydrogenation catalyst comprises a first component selected from the group consisting of Group VIII noble metals and mixtures thereof, a second component selected from the group consisting of alkali metals or alkaline-earth metals and mixtures thereof, and a third component selected from the group consisting of tin, germanium, lead, indium, gallium, thallium and mixtures thereof; and a support to carry the first, second, and third components thereby forming a catalyst particle wherein the catalyst particle comprises a plurality of pores, wherein at least 15% of the pores have an average pore diameter between 200 to 350 Angstroms, wherein the catalyst particle has a median diameter between 1.6 mm and 2.5 mm, and an apparent bulk density between 0.6 and 0.3 g/cc;
wherein the dehydrogenation conditions in the at least one reactor include a hydrogen to hydrocarbon molar ratio in a range of 0.01 to 0.40 and a reactor inlet temperature in a range of 500°-645° C.

2. The process of claim 1 wherein the hydrogen to hydrocarbon molar ratio is in the range of 0.01-0.35 and the reactor inlet temperature is in the range of 500°-640° C.

3. The process of claim 1 wherein the hydrogen to hydrocarbon molar ratio is in the range of 0.01-0.25 and the reactor inlet temperature is in the range of 500°-630° C.

4. The process of claim 1 wherein the hydrogen to hydrocarbon molar ratio is in the range of 0.01-0.15 and the reactor inlet temperature is in the range of 500°-620° C.

5. The process of claim 1 further comprising separating the dehydrogenation zone product stream into a hydrocarbon rich product stream and hydrogen rich product stream.

6. The process of claim 5 further comprising passing a portion of the hydrogen rich stream to the dehydrogenation zone.

7. The process of claim 1 wherein the hydrocarbon feed comprises at least one paraffin having 2 to 30 carbon atoms.

8. The process of claim 1 wherein the hydrocarbon feed comprises at least one paraffin having 2 to 6 carbon atoms.

9. The process of claim 1 wherein the hydrocarbon feed comprises at least one paraffin having 3 to 4 carbon atoms.

10. A process for dehydrogenation of a hydrocarbon feedstock, the process comprising:
passing a feed stream comprising hydrogen and paraffins into a dehydrogenation zone comprising at least one reactor containing a dehydrogenation catalyst maintained at dehydrogenation conditions to produce a dehydrogenation zone product stream comprising hydrogen, light ends, paraffins, and olefins, wherein the dehydrogenation catalyst comprises a first component selected from the group consisting of Group VIII noble metals and mixtures thereof, a second component selected from the group consisting of alkali metals or alkaline-earth metals and mixtures thereof, and a third component selected from the group consisting of tin, germanium, lead, indium, gallium, thallium and mixtures thereof; and a support to carry the first, second, and third components thereby forming a catalyst particle wherein the catalyst particle comprises a plurality of pores, wherein at least 15% of the pores have an average pore diameter between 200 to 350 Angstroms, wherein the catalyst particle has a median diameter between 1.6 mm and 2.5 mm, and an apparent bulk density between 0.6 and 0.3 g/cc;
wherein the dehydrogenation conditions in the at least one reactor include a hydrogen to hydrocarbon molar ratio, a reactor inlet temperature, and a coke index, wherein the hydrogen to hydrocarbon molar ratio is in a range of 0.01 to 0.4, wherein one dehydrogenation condition is adjusted based on the other two dehydrogenation conditions, and wherein the coke index is determined by measuring coking for a range of reactor inlet temperature and hydrogen to hydrocarbon molar ratio combinations and determining a correlation between the reactor inlet temperature and the hydrogen to hydrocarbon molar ratio.

11. The process of claim 10 wherein either the reactor inlet temperature is adjusted based on a selected hydrogen to hydrocarbon molar ratio and the coke index or the hydrogen to hydrocarbon molar ratio is adjusted based on a selected reactor inlet temperature and the coke index.

12. The process of claim 10 wherein the coke index is in a range of 0-250.

13. The process of claim 10
wherein a desired reactor inlet temperature is determined using the correlation and the selected hydrogen to hydrocarbon molar ratio and wherein the reactor inlet temperature is adjusted to the determined reactor inlet temperature; or wherein a desired hydrogen to hydrocarbon molar ratio is determined using the correlation and the selected reactor inlet temperature and wherein the hydrogen to hydrocarbon molar ratio is adjusted to the determined hydrogen to hydrocarbon molar ratio.

14. The process of claim 10 wherein the hydrocarbon feed comprises at least one paraffin having 2 to 30 carbon atoms.

15. The process of claim 10 wherein the hydrocarbon feed comprises at least one paraffin having 2 to 6 carbon atoms.

16. The process of claim 10 wherein the hydrocarbon feed comprises at least one paraffin having 3 to 4 carbon atoms.

17. The process of claim 10 further comprising separating the dehydrogenation zone product stream into a hydrocarbon rich product stream and hydrogen rich product stream.

18. The process of claim 17 further comprising passing a portion of the hydrogen rich stream to the dehydrogenation zone.

Assignees

• Uop Llc

Inventors

• Digiulio Christopher
• Serban Manuela
• Sadler Clayton C

Classifications

• B01J8/02

  with stationary particles, e.g. in fixed beds · CPC title

• B01J2208/00017

  Controlling the temperature · CPC title

• B01J2208/00805

  Details of the particulate material · CPC title

• C07C2521/04

  Alumina · CPC title

• C07C5/3337 Primary

  of the platinum group · CPC title