Catalyzed ceramic candle filter and method for cleaning of off- or exhaust gases

Patent metadata

Field	Value
Publication number	US-10105682-B2
Application number	US-201515545499-A
Country	US
Kind code	B2
Filing date	Mar 20, 2015
Priority date	Mar 20, 2015
Publication date	Oct 23, 2018
Grant date	Oct 23, 2018

Abstract

Ceramic candle filter and use of the filter in the removal of particulate matter in form of soot, ash, metals and metal compounds, together with hydrocarbons and nitrogen oxides being present in process off-gas or engine exhaust gas, the filter comprises a combined SCR and oxidation catalyst arranged at least on the dispersion side and/or within wall of the filter, the combined SCR and oxidation catalyst comprises palladium, a vanadium oxide and titania.

First claim

The invention claimed is:

1. A ceramic candle filter suitable for the removal of particulate matter in form of soot, ash, metals and metal compounds, together with hydrocarbons and nitrogen oxides being present in process off-gas or engine exhaust gas, the filter comprises a combined SCR and oxidation catalyst arranged at least on the dispersion side and/or within wall of the filter, the combined SCR and oxidation catalyst comprises palladium, a vanadium oxide and titania, wherein the ceramic material of the filter is selected from the group of silica-aluminate, calcium-magnesium-silicates, calcium-silicates fibers, or a mixture thereof.

2. The ceramic candle filter of claim 1 , wherein the catalyst contains palladium in an amount of between 20 and 1000 ppm/weight of the filter.

3. The ceramic candle filter according to claim 1 , wherein the ceramic material of the filter consists of bio-soluble fibres selected from the group of calcium-magnesium-silicates.

4. A method for the removal of particulate matter in form of soot, ash, metals and metal compounds, together with hydrocarbons and nitrogen oxides being present in process off-gas or engine exhaust gas, comprising the steps of
providing a process off-gas or engine exhaust gas containing a nitrogenous reductant or adding the nitrogenous reductant to the off- or exhaust gas;
passing the off-gas or the exhaust through a ceramic candle filter and capturing the particulate matter; and
reducing amounts of soot in the particulate matter captured on the at least one particulate filter and reducing amounts of nitrogen oxides and hydrocarbons in the off- or exhaust gas by oxidation of the hydrocarbons and by selective catalytic reduction (SCR) of the nitrogen oxides with the nitrogenous reductant in contact with a combined SCR and oxidation catalyst being arranged on the dispersion side and/or within wall of the filter, wherein the combined SCR and oxidation catalyst comprises palladium, a vanadium oxide and titania.

5. The method according to claim 4 , wherein combined oxidation and SCR catalyst contains palladium in an amount of between 20 and 1000 ppm/weight of the filter.

6. The method of claim 4 , wherein the ceramic material of the filter is selected from silica-aluminate, calcium-magnesium-silicates, calcium-silicates fibers, or a mixture thereof.

7. The method according to claim 4 , wherein the ceramic material of the filter comprises bio-soluble fibres selected from the group of calcium-magnesium-silicates.

Assignees

• Haldor Topsoe As

Inventors

• Castellino Francesco
• Pedersen Lars Storm

Classifications

• B01J2523/00

  Constitutive chemical elements of heterogeneous catalysts · CPC title

• B01D53/9468

  in different layers · CPC title

• B01J37/0234

  Impregnation and coating simultaneously · CPC title

• F01N3/0222

  the structure being monolithic, e.g. honeycombs · CPC title

• B01D2255/9155

  Wall flow filters · CPC title