Method for monitoring performance of process catalysts

Patent metadata

Field	Value
Publication number	US-9322793-B2
Application number	US-201113640344-A
Country	US
Kind code	B2
Filing date	Apr 8, 2011
Priority date	May 20, 2010
Publication date	Apr 26, 2016
Grant date	Apr 26, 2016

Abstract

Disclosed is a method for determining when to replace a guard bed material used to remove one or more catalyst poisons from a feed based on a parameter change in a process. A guard bed having a guard bed material is in fluid communication with a catalyst bed having a catalyst. At least three monitors are positioned in said guard bed or said catalyst bed and at least one parameter of the guard bed or catalyst bed is monitored. A feed component comprising one or more catalyst poisons is supplied to said guard bed or said catalyst bed. The feed is contacted with said guard bed material or said catalyst to remove at least a portion of a catalyst poison and to form a product which produces an increase or a decrease in said parameter. The monitored parameters are compared to determine when to replace the guard bed material.

First claim

The invention claimed is:

1. A method for determining when to replace a guard bed material used to remove a catalyst poison from a feed based on a temperature change in an aromatic alkylation process, said method comprising the steps of:
(a) providing a guard bed comprising a guard bed material, said guard bed having an inlet and a downstream outlet;
(b) placing at least three guard bed temperature measuring devices proximate said guard bed, wherein a first guard bed temperature measuring device is located proximate said inlet to said guard bed, a third guard bed temperature measuring device is located downstream of said outlet of said guard bed, and one or more second guard bed temperature measuring devices are located downstream of said inlet of said guard bed and upstream of said outlet of said guard bed;
(c) monitoring at least one temperature of said guard bed with each of said at least three guard bed temperature measuring devices;
(d) supplying a benzene feed to said guard bed and at least intermittently supplying an alkylating agent feed to said guard bed from at least 1 hour up to 24 hours or more and then interrupted for periods of 10 to 15 days or more, wherein said feed comprises a catalyst poison;
(e) contacting said feeds with said guard bed material under suitable guard bed treatment conditions to remove at least a portion of said catalyst poison from said feed and to form a treated feed, wherein said contacting produces an exothermic reaction and an increase in said guard bed temperature;
(f) determining a first guard bed delta as the absolute value of the difference between said guard bed temperature at said first guard bed temperature measuring device and said guard bed temperature at said third guard bed temperature measuring device;
(g) determining a second guard bed delta as the absolute value of the difference between said guard bed temperature at said first guard bed temperature measuring device and said guard bed temperature at said second guard bed temperature measuring device; and
(h) replacing said guard bed material when the ratio of said second guard bed delta to said first guard bed delta is less than 1.

2. The method of claim 1 , further comprising the steps of:
(i) providing a catalyst bed comprising a catalyst, wherein said catalyst bed is located downstream of and in fluid communication with said guard bed; and
(j) contacting said treated feed with said catalyst under suitable conversion conditions to form a product.

3. The method of claim 1 , wherein said guard bed material extends from said inlet to said outlet of said guard bed.

4. The method of claim 3 , wherein at least one of said second guard bed temperature measuring device is placed upstream of and proximate to said outlet of said guard bed.

5. The method of claim 3 , wherein at least one of said second guard bed temperature measuring device is placed at 70%, 80% or 90% of the distance measured from said inlet to said outlet of said guard bed.

6. The method of claim 5 , wherein said ratio of said second guard bed delta to said first guard bed delta is selected from the group consisting of 0.9, 0.8, 0.7, 0.6, and 0.5.

7. The method of claim 6 , wherein said guard bed material is a solid acid.

8. The method of claim 7 , wherein said solid acid is selected from the group consisting of acidic aluminas, acidic silicas, acidic silica-aluminas, acidic clays, acidic zeolites, and acidic mesoporous aluminosilicates.

9. The method of claim 7 , wherein said solid acid comprises a molecular sieve selected from the group consisting of: ZSM-5, ZSM-11, ZSM-35, clinoptilolite, ferrierite, stilbite, EU-1, NU-87, mordenite, omega, beta, faujasite, gmelinite, ZSM-12, cancrinite, and zeolite L.

10. The method of claim 1 , wherein said catalyst poison comprises an impurity having at least one of the following elements: nitrogen, halogens, oxygen, sulfur, arsenic, selenium, tellurium, phosphorus, and Group 1 through Group 12 metals.

11. The method of claim 2 , wherein said catalyst is an alkylation catalyst, said treated feed comprises an alkylated aromatic component, said alkylating agent feed comprises ethylene and said alkylated aromatic component comprises ethylbenzene, or said alkylating agent feed comprises propylene and said alkylated aromatic component comprises cumene, or said alkylating agent feed comprises butene and said alkylated aromatic component comprises sec-butyl benzene.

12. The method of claim 11 , wherein said alkylation catalyst comprises a molecular sieve having unit cells of MWW framework topology and characterized by an X-ray diffraction pattern including d-spacing maxima at 12.4±0.25, 3.57±0.07, and 3.42±0.07 Angstroms.

13. The method of claim 12 , wherein said alkylation catalyst is selected from the group consisting of ERB-1, ITQ-1, ITQ-2, ITQ-30, PSH-3, SSZ-25, MCM-22, MCM-36, MCM-49, MCM-56, UZM-8, EMM-10, EMM-10P, EMM-12, EMM-13, and mixtures thereof.

14. The method of claim 11 , wherein said alkylation catalyst is selected from the group consisting of MCM-22 family material, zeolite beta, faujasite, zeolite Y, Ultrastable Y (USY), Dealuminized Y (Deal Y), Rare Earth Y (REY), Ultrahydrophobic Y (UHP-Y), mordenite, TEA-mordenite, ZSM-3, ZSM-4, ZSM-14, ZSM-18, ZSM-20, and combinations thereof.

Assignees

• Vincent Matthew J
• Fletcher David L
• Nanda Vijay
• Exxonmobil Chem Patents Inc

Inventors

• Vincent Matthew J
• Fletcher David L
• Nanda Vijay

Classifications

• C10G2300/1096

  Aromatics or polyaromatics · CPC title

• C10G2300/205

  Metal content · CPC title

• C10G47/36

  Controlling or regulating · CPC title

• C10G61/00

  Treatment of naphtha by at least one reforming process and at least one process of refining in the absence of hydrogen · CPC title

• B01J29/70

  of types characterised by their specific structure not provided for in groups B01J29/08 - B01J29/65 · CPC title