US 6,854,266 B2 · Method for desulfurizing a storage medium

Abstract

A method of desulfurization of a ceramic storage medium for sulfur oxides and/or nitrogen oxides situated in a gas stream, in particular a storage device for nitrogen oxides or sulfur oxides situated in the exhaust gas stream of an internal combustion engine, is described, a mixture having a low oxygen concentration being established in the gas stream to release the stored sulfur oxides. A measuring signal is recorded by an oxygen probe positioned downstream from the storage medium in a gas stream flow direction, the curve of this measuring signal being used to determine the loading of the storage medium with sulfur oxides. This method allows determination of the need for desulfurization as a function of the loading of the storage medium with sulfur oxides, to monitor and control the progress of desulfurization initiated and to check on how complete the desulfurization that is concluded has been.

Claims10

Dependent claims

A method of desulfurization of a storage medium for at least one of nitrogen oxides and sulfur oxides situated in a gas stream, comprising:

recording a measuring signal using an oxygen probe situated downstream from the storage medium in a direction of flow of the gas stream;
using a plotted curve of the measuring signal over time to determine a loading of the storage medium with sulfur oxides, wherein desulfurization is initiated as a function of the plotted curve;
establishing a mixture having a low oxygen concentration in the gas stream at predetermined intervals for determining the loading of the storage medium;
and
using a change in the measuring signal of the oxygen probe as a measure of a need for desulfurization of the storage medium after establishing the mixture having the low oxygen concentration in the gas stream;
wherein a difference between a first measuring signal of the oxygen probe upon initial establishment of the mixture having the low oxygen concentration and a second measuring signal at an end of establishment of the mixture having the low oxygen concentration in the gas stream is used as a measure of the loading of the storage medium with sulfur oxides, and wherein a desulfurization of the storage medium is initiated when an absolute value of the difference drops below a predetermined value.

3 more elements

A method of desulfurization of a storage medium for at least one of nitrogen oxides and sulfur oxides situated in a gas stream, comprising:

recording a measuring signal using an oxygen probe situated downstream from the storage medium in a direction of flow of the gas stream;
using a plotted curve of the measuring signal over time to determine a loading of the storage medium with sulfur oxides, wherein desulfurization is initiated as a function of the plotted curve;
establishing a mixture having a low oxygen concentration in the gas stream at predetermined intervals for determining the loading of the storage medium;
and
using a change in the measuring signal of the oxygen probe as a measure of a need for desulfurization of the storage medium after establishing the mixture having the low oxygen concentration in the gas stream;
wherein a gradient of the change in the measuring signal of the oxygen probe after establishing a mixture having a low oxygen concentration in the gas stream is used as a measure of the loading of the storage medium with sulfur oxides, and wherein a desulfurization of the storage medium is initiated when a maximum absolute value of the gradient drops below a predetermined value.

3 more elements

Dependencies are inferred from the claim text.

Method for desulfurizing a storage medium

Life of this patent

Method for desulfurizing a storage medium

Life of this patent

Abstract

Claims10