Catalyst for treating an exhaust gas, an exhaust system and a method

Patent metadata

Field	Value
Publication number	US-10773252-B2
Application number	US-201815937896-A
Country	US
Kind code	B2
Filing date	Mar 28, 2018
Priority date	Mar 30, 2017
Publication date	Sep 15, 2020
Grant date	Sep 15, 2020

Abstract

A catalyst for treating an exhaust gas comprising SO2, NOx and elemental mercury in the presence of a nitrogenous reductant comprises a composition containing oxides of: (i) Molybdenum (Mo) and/or Tungsten (W); (ii) Vanadium (V); (iii) Titanium (Ti), and (iv) an MFI zeolite, wherein the composition comprises, based on the total weight of the composition: (i) 1 to 6 wt % of MoO3 and/or 1 to 10 wt % WO3; and (ii) 0.1 to 3 wt % V2O5, and (iii) 48.5 to 94.5 wt % TiO2; and (iv) 35 to 50 wt % MFI zeolite.

First claim

The invention claimed is:

1. A catalyst for treating an exhaust gas comprising SO 2 , NO x and elemental mercury in the presence of a nitrogenous reductant, the catalyst comprising a composition containing oxides of:
(i) Molybdenum (Mo) and/or Tungsten (W);
(ii) Vanadium (V);
(iii) Titanium (Ti); and
(iv) an MFI zeolite,
wherein the composition comprises, based on the total weight of the composition:
(i) 1 to 6 wt % of M o O3 and/or 1 to l0 wt % WO 3 ; and
(ii) 0.1 to 3 wt % V 2 O 5 ; and
(iii) 48.5 to 94.5 wt % TiO 2 ; and
(iv) 35 to 50 wt % MFI zeolite.

2. The catalyst according to claim 1 , wherein the composition does not comprise phosphorus.

3. The catalyst according to claim 1 , wherein the composition consists of the MFI zeolite and the oxides of Mo, W, V, and Ti.

4. The catalyst according to claim 1 , wherein the catalyst is a plate catalyst.

5. The catalyst according to claim 1 , wherein the MFI zeolite is an H-MFI zeolite.

6. The catalyst according to claim 1 , wherein the MFI zeolite is an H-ZSM-5 zeolite.

7. A method for treating an exhaust gas comprising SO 2 , NO x and elemental mercury, the method comprising:
contacting a flow of exhaust gas with the catalyst of claim 1 in the presence of a nitrogenous reducing agent to thereby provide a treated exhaust gas.

8. The method according to claim 7 , wherein the nitrogenous reducing agent is ammonia, hydrazine or an ammonia precursor selected from the group consisting of urea ((NH 2 ) 2 CO), ammonium carbonate, ammonium carbamate, ammonium hydrogen carbonate and ammonium formate.

9. The exhaust system of claim 8 , wherein the combustion source is a furnace or a boiler, of a coal or oil power plant, a cement plant or a waste incinerator.

10. A exhaust system for a combustion source for treating an exhaust gas comprising SO 2 , NO x and elemental mercury, the system comprising a conduit for carrying a flowing exhaust gas, a source of nitrogenous reductant, a catalyst according to claim 1 disposed in a flow path of the exhaust gas and means for metering nitrogenous reductant into a flowing exhaust gas upstream of the catalyst.

11. The exhaust system according to claim 10 , the system further comprising a wet or a dry scrubber for recovering oxidized mercury from the treated exhaust gas.

Assignees

• Johnson Matthey Plc

Inventors

• Alcove Clave Silvia
• Andersen Paul
• Brandmair Maria
• Huber Manop
• Nash Michael
• Repp David

Classifications

• B01J2229/186

  not in framework positions · CPC title

• B01J29/48 Primary

  containing arsenic, antimony, bismuth, vanadium, niobium tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium · CPC title

• B01D2255/20776

  Tungsten · CPC title

• B01D2255/20769

  Molybdenum · CPC title

• B01D2255/20707

  Titanium · CPC title