Method and system for the removal of particulate matter from engine exhaust gas or process equipment

Patent metadata

Field	Value
Publication number	US-10196949-B2
Application number	US-201615560043-A
Country	US
Kind code	B2
Filing date	Mar 17, 2016
Priority date	Mar 23, 2015
Publication date	Feb 5, 2019
Grant date	Feb 5, 2019

Abstract

Method and system for removal of particles such as soot, ash and heavy metals, and optionally additionally NO X and SO X being present in exhaust gas from an engine or process equipment.

First claim

The invention claimed is:

1. Method for removal of soot, hydrocarbons, ash and heavy metals being present in exhaust gas from an engine or process equipment, comprising the steps of:
passing the exhaust gas at exhaust gas temperature through at least one filtration unit, each comprising at least one particulate filter and capturing particles, soot, ash and heavy metals contained in the exhaust gas, wherein the at least one filtration unit is arranged in a pressure vessel upstream or downstream an engine turbocharger or a cement production process;
continuously burning the captured soot and adhered hydrocarbons off the at least one particulate filter by contact with a catalyst being arranged on the filter;
periodically opening at least one particle discharge valve in a particle discharge valve arrangement comprising a particle collector mounted at each of the inlets for the filtration units;
subsequently pulse injecting air into the outlet of at least one of the filtration units in reverse to the previous flow of the exhaust gas and blowing the particles off the at least one particulate filter;
closing the at least one particle discharge valve; and
subsequently repeating the reverse pulse process for all the one or more filtration units without shutting off said filtration units from the exhaust gas.

2. The method of claim 1 , wherein the at least one particulate filter is in form of a wall flow filter.

3. The method of claim 2 , wherein the catalyst is coated on or inside the walls of the at least one particulate filter.

4. The method of claim 1 , wherein the catalyst comprises of titanium dioxide, oxides of vanadium and tungsten and metallic palladium.

5. The method of claim 1 , wherein body of the at least one particulate filter is prepared from silicon carbide, cordierite, mullite, aluminium titanate or sintered metal.

6. The method of claim 1 , wherein the air is pulse injected with injection pulse duration of between 10 and 600 msec, and wherein the particle discharge valve is opened between 1 and 5 sec before the injection pulse duration and closed between 2 and 15 sec after the injection pulse duration.

7. The method of claim 1 , wherein the air for pulse injection is withdrawn from an accumulator tank with compressed air at a pressure 4 to 10 barg.

8. The method of claim 1 , wherein the exhaust gas is passed through the at least one filtration unit at a pressure of between 0 and 3 barg.

9. The method of claim 1 , comprising the further step of selective catalytic reduction of nitrogen oxides in the exhaust gas prior to the gas is passed through the at least one filtration unit or after the gas has passed through the at least one filtration unit.

10. The method according to claim 1 , comprising the further step of reducing amounts of sulphur oxides contained in the exhaust gas by scrubbing the gas with an alkaline solution or sea water in an open or closed loop, downstream of the at least one filtration unit.

11. The method according to claim 1 , wherein the exhaust gas temperature of the exhaust gas which is passed through the at least one filtration unit is kept in the temperature range of 380° C.-420° C. to avoid that any particles, soot, ash and heavy metals contained in the exhaust gas are fixed too hard to said filtration unit for the reverse pulse to remove them.

12. Filtration assembly for removal of particles of soot and ash present in exhaust gas from an engine or process equipment, comprising:
one or more exhaust gas inlet pipes connecting each the engine or process equipment with the inlet of each of one or more filtration units, wherein the one or more filtration units are arranged in a pressure vessel upstream or downstream an engine turbocharger or a cement production process;
one or more exhaust gas outlet pipes in fluid communication with the outlet of each of the one or more filtration units;
at least one particulate filter catalyzed with a catalyst for effectuating burning off of soot with adhered hydrocarbons connected in parallel within the one or more filtration units;
an air pulse jet valve arrangement mounted at the outlet of the one or more filtration units for pulse cleaning, blowing off ash from the at least one particulate filter, where the air pulse jet valve arrangement comprises one or more pulse valves, one or more air blow pipes connected to an air supply and nozzles in the blow pipes for pulse injection of air through the nozzles in the blow pipes into the at least one particulate filter; and
a particle discharge valve arrangement mounted at the inlet of the one or more filtration units, for collecting soot and ash from the at least one particulate filter during air pulse cleaning, said particle discharge valve arrangement comprising one or more particle discharge valves, one or more dust discharge pipes and one or more particle collectors mounted at the exhaust gas inlet of the one or more filtration units.

13. The system of claim 12 , wherein the at least one particulate filter is in form of a wall flow filter.

14. The system of claim 13 , wherein the at least one particulate filter is coated on walls or inside walls with a catalyst catalysing burning of captured soot of the filters.

15. The system of claim 12 , wherein the catalyst consists of titanium dioxide, oxides of vanadium and tungsten and metallic palladium.

16. The system according to claim 12 , wherein the body of the at least one particulate filter is prepared from silicon carbide, cordierite, or mullite or aluminium titanate or sintered metal.

17. The system of claim 12 , wherein the one or more air blow pipes are connected to an accumulator tank with compressed air.

18. The system of claim 12 , wherein the one or more exhaust gas outlet pipes connect the one or more filtration units to a downstream selective catalytic reduction unit comprising a denitrification catalyst.

19. The system of claim 12 , wherein the one or more exhaust gas inlet pipes connect the one or more filtration units to an upstream selective catalytic reduction unit comprising a denitrification catalyst.

20. The system of claim 12 , wherein the one or more exhaust gas outlet pipes connect the one or more filtration units to a scrubber unit.

21. The system of claim 12 , wherein a selective catalytic reduction unit comprising a denitrification catalyst unit is connected upstream to the one or more filtration units and downstream to a scrubbing unit.

22. The system of claim 12 , wherein the selective catalytic reduction unit is arranged upstream or downstream an engine turbocharger.

23. The system of claim 12 , further comprising a by-pass pipe by-passing the exhaust gas at least one of the one or more filtration units.

24. The system of claim 12 , wherein a heat exchanger is arranged up-stream the one or more filtration units to ensure that the exhaust gas temperature of the exhaust gas which is passed through said filtration units is kept below 420° C.

Assignees

• Haldor Topsoe As
• Ecospray Tech Srl
• Haldor Topsoe As

Inventors

• Archetti Maurizio

Classifications

• F01N3/2803

  characterised by structure, by material or by manufacturing of catalyst support · CPC title

• F01N2590/02

  for marine vessels or naval applications · CPC title

• F01N2510/06

  for exhaust purification, e.g. catalytic reaction · CPC title

• B01J23/44

  Palladium · CPC title

• F01N3/30

  Arrangements for supply of additional air (control, e.g. using by-passes or variable air pump drives, F01N3/22) · CPC title