Characterization of solid catalysts

Patent metadata

Field	Value
Publication number	US-2021156830-A1
Application number	US-201916696828-A
Country	US
Kind code	A1
Filing date	Nov 26, 2019
Priority date	Nov 26, 2019
Publication date	May 27, 2021
Grant date	—

Abstract

Examples described herein provide a method for characterizing a catalyst in a chemisorption unit. The method includes treating a catalyst sample with gas blend comprising ammonia in an inert gas and performing a first temperature programmed desorption (TPD) to desorb the ammonia from the catalyst sample. A temperature programmed reduction (TPR) of the catalyst sample is performed with hydrogen. The catalyst sample is treated after the TPR with a gas blend comprising ammonia in an inert gas. A second temperature programmed desorption is performed to desorb the ammonia from the catalyst sample.

First claim

What is claimed is:

1 . A method for characterizing a catalyst in a chemisorption unit, comprising:
treating a catalyst sample with a gas blend comprising ammonia in an inert gas; performing a first temperature programmed desorption (TPD) to desorb the ammonia from the catalyst sample; performing a temperature programmed reduction (TPR) of the catalyst sample with hydrogen; treating the catalyst sample after the TPR with a gas blend comprising ammonia in an inert gas; and performing a second temperature programmed desorption (TPD) to desorb the ammonia from the catalyst sample.

2 . The method of claim 1 , comprising:
loading the catalyst sample in the chemisorption unit; and drying the catalyst sample by flowing the inert gas over the catalyst sample while ramping a temperature of the catalyst sample from about 50° C. to about 500° C. at about 10° C./min.

3 . The method of claim 1 , wherein treating the catalyst sample with a gas blend comprises flowing a blend of 10% ammonia in helium at a flow rate of about 30 cc/min for about 35 minutes at about 50° C.

4 . The method of claim 1 , wherein performing the first temperature programmed desorption comprises:
flowing a carrier gas over the catalyst sample, wherein the carrier gas comprises helium; ramping a temperature of the catalyst sample from about 50° C. to about 550° C. at about 10° C./min; and collecting data from a thermal conductivity detector to measure ammonia desorbed at a temperature during the ramping.

5 . The method of claim 1 , comprising measuring an amount of the ammonia desorbed from the catalyst sample during the first TPD versus time by plotting a response from a thermal conductivity detector versus temperature.

6 . The method of claim 5 , comprising measuring a total acidity of the catalyst sample by integrating an area of a measured response from the thermal conductivity detector.

7 . The method of claim 5 , comprising determining a relative acid strength of the catalyst sample by comparing peak locations of the ammonia released from other catalyst samples.

8 . The method of claim 5 , comprising cooling the catalyst sample under a flow of the inert gas.

9 . The method of claim 1 , comprising measuring an amount of hydrogen adsorbed by the catalyst sample during the TPR by measuring an amount of hydrogen removed from a carrier gas.

10 . The method of claim 1 , wherein performing the TPR of the catalyst sample with hydrogen comprises:
flowing a carrier gas over the catalyst sample, wherein the carrier gas comprises a gas blend of 5% hydrogen in argon; ramping the temperature of the catalyst sample from about 50° C. to about 800° C. at about 10° C./min; and collecting data from a thermal conductivity detector to measure an amount of hydrogen removed from the carrier gas at a temperature during the ramping.

11 . The method of claim 10 , comprising determining an activity of the catalyst sample by integrating peaks of the hydrogen adsorbed during the TPR.

12 . The method of claim 10 , comprising determining a number of active sites of the catalyst sample by determining a number of peaks in a plot of the TPR.

13 . The method of claim 10 , comprising dispersing at least a portion of metal sites by performing the TPR.

14 . The method of claim 1 , wherein treating the catalyst sample after the TPR comprises flowing a gas blend comprising 10% ammonia in helium over the catalyst sample at a flow rate of about 30 cc/min for about 35 minutes at about 50° C.

15 . The method of claim 14 , wherein performing the second temperature programmed desorption comprises:
flowing a carrier gas over the catalyst sample, wherein the carrier gas comprises helium; ramping the temperature of the catalyst sample from about 50° C. to about 550° C. at about 10° C./min; and collecting data from a thermal conductivity detector to measure ammonia desorbed at a temperature during the ramping.

16 . The method of claim 14 , comprising measuring an amount of the ammonia desorbed from the catalyst sample during the second TPD versus time by plotting a response from a thermal conductivity detector versus temperature.

17 . The method of claim 16 , comprising measuring a total acidity of the catalyst sample by integrating an area of a measured response from the thermal conductivity detector.

18 . The method of claim 16 , comprising determining a relative acid strength of the catalyst sample by comparing peak locations of the ammonia released from other catalyst samples.

19 . The method of claim 1 , comprising determining a change in acid strength of the catalyst sample by comparing results from the second temperature programmed desorption to results of the first temperature programmed desorption.

Assignees

• Saudi Arabian Oil Co

Inventors

• Al-Eid Manal
• Ding Lianhui

Classifications

• B01D53/58 Primary

  Ammonia · CPC title

• B01D53/00

  Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols, (recovery of volatile solvents by condensation B01D5/00; sublimation B01D7/00; cold traps, cold baffles B01D8/00; working-up undefined gaseous mixtures obtained by cracking hydrocarbon oils C10G70/00; cleaning coal gas C10K; working-up of natural gas, or synthetic natural gas, C10L3/10; separation of difficult-to-condense gases or air by liquefaction F25J; for investigating materials G01N30/00) · CPC title

• Y02A50/20

  Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters · CPC title

• G01N33/0026 Primary

  using an alternating circulation of another gas · CPC title

• G01N25/18

  by investigating thermal conductivity (by calorimetry G01N25/20; by measuring change of resistance of an electrically-heated body G01N27/18) · CPC title