Process and apparatus for the catalytic elimination of a pollutant from the exhaust gas from a combustion installation

A process for the catalytic removal of a pollutant from an exhaust gas from a diesel engine, which comprises:

• calculating, from operationally relevant parameters of a combustion installation, a concentration of a pollutant in an exhaust gas with a predetermined characteristic diagram;
• introducing a predetermined quantity of a reagent into the exhaust gas per unit time as a function of the calculated concentration of the pollutant, the reagent reacting with the pollutant at a catalytic converter;
• determining operating states of the combustion installation with substantially constant pollutant emission levels;
• determining, with a sensor, the concentration of the pollutant in the exhaust gas during an operating state of the combustion installation with a substantially constant pollutant emission level and using only a concentration of the pollutant from a combustion installation in a steady operating state to correct the characteristic diagram;
• and
• calculating the concentration of the pollutant in the exhaust gas from a combustion installation with the characteristic diagram in a non-steady operating state.

An apparatus for the catalytic removal of a pollutant from exhaust gas of a combustion installation having operationally relevant parameters, comprising:

• an exhaust-gas duct connected to a combustion installation for directing flow of an exhaust gas containing at least one pollutant;
• a sensor disposed in said exhaust-gas duct for producing output values;
• a reagent;
• an introduction apparatus for introducing said reagent into the exhaust gas;
• a catalytic converter for reacting said reagent with the at least one pollutant, said catalytic converter fluidically connected to said exhaust-gas duct to conduct the exhaust gas flow;
• a predetermined characteristic diagram;
• a control unit for receiving operationally relevant parameters of the combustion installation, said control unit connected to said sensor, to said characteristic diagram, to the combustion installation, and to said introduction apparatus;
• said control unit programmed to calculate a concentration of the at least one pollutant from the operationally relevant parameters based on said predetermined characteristic diagram and to control a throughput of said reagent in said introduction apparatus as a function of a calculated concentration;
• and
• said control unit programmed:
• to determine the concentration of the at least one pollutant based upon said output values from said sensor;
• to detect an operating state of the combustion installation with a substantially constant pollutant emission level;
• and
• to correct said characteristic diagram only based on a value of the concentration of the at least one pollutant from the combustion installation in a steady operating state determined by said sensor during such an operating state.

An apparatus for the catalytic removal of a pollutant from exhaust gas of a diesel engine having operationally relevant parameters, comprising:

• an exhaust-gas duct connected to a combustion installation for directing flow of an exhaust gas containing at least one pollutant;
• a sensor disposed in said exhaust-gas duct for producing output values;
• a reagent;
• an introduction apparatus for introducing said reagent into the exhaust gas;
• a catalytic converter for reacting said reagent with the at least one pollutant, said catalytic converter fluidically connected to said exhaust-gas duct to conduct the exhaust gas flow;
• a predetermined characteristic diagram;
• a control unit for receiving operationally relevant parameters of the combustion installation, said control unit connected to said sensor, to said characteristic diagram, to the combustion installation, and to said introduction apparatus;
• said control unit programmed to calculate a concentration of the at least one pollutant from the operationally relevant parameters based on said predetermined characteristic diagram and to control a throughput of said reagent in said introduction apparatus as a function of a calculated concentration;
• and
• said control unit programmed:
• to determine the concentration of the at least one pollutant based upon said output values from said sensor;
• to detect an operating state of the combustion installation with a substantially constant pollutant emission level;
• and
• to correct said characteristic diagram only based on a value of the concentration of the at least one pollutant from the combustion installation in a steady operating state determined by said sensor during such an operating state.