Measurement of NO and NO2 for control of selective catalytic reduction
AssigneeHoneywell International Inc.
InventorsGregory E. Stewart, David Germann
Life of this patent
Estimating the term…
Abstract
A selective catalytic reduction system includes a catalyst, a device to measure an amount of nitrogen oxide (NO), a device to measure an amount of nitrogen dioxide (NO2), a device to add an ammonia source, and a control unit to calculate the amount of ammonia source to add as a function of a ratio of an amount of nitrogen oxide and an amount of nitrogen dioxide or an absolute amount of nitrogen oxide and an absolute amount of nitrogen dioxide.
Claims20
An apparatus comprising:
- a device to determine an amount of nitrogen oxide (NO) in a diesel engine exhaust;
- a device to determine an amount of nitrogen dioxide (NO2) in the diesel engine exhaust;
- and
- a control unit to calculate an amount of an ammonia source to add as a function of a ratio of the amount of nitrogen oxide and the amount of nitrogen dioxide, or as a function of an absolute amount of nitrogen oxide and an absolute amount of nitrogen dioxide.
A process comprising:
- determining an amount of nitrogen oxide (NO) in a diesel engine exhaust;
- determining an amount of nitrogen dioxide (NO2) in the diesel engine exhaust;
- dosing an amount of an ammonia source as a function of a ratio of the amount of nitrogen oxide and the amount of nitrogen dioxide or as a function of an absolute amount of nitrogen oxide and an absolute amount of nitrogen dioxide;
- converting the ammonia source into ammonia;
- and
- reacting the nitrogen oxide and the nitrogen dioxide with the ammonia in the presence of a catalyst.
A machine readable medium comprising instructions that when executed by a processor executes a process comprising:
- determining an amount of nitrogen oxide (NO) in a diesel engine exhaust;
- determining an amount of nitrogen dioxide (NO2) in the diesel engine exhaust;
- and
- dosing an amount of an ammonia source as a function of a ratio of the amount of nitrogen oxide and the amount of nitrogen dioxide or an absolute amount of the nitrogen oxide and an absolute amount of the nitrogen dioxide;
- whereby the ammonia source is converted into ammonia;
- and
- whereby the nitrogen oxide and the nitrogen dioxide react with the ammonia in the presence of a catalyst.
Dependencies are inferred from the claim text.