A pfr lime kiln provided with a nox abatement system

A method for reducing NOx in exhaust gas produced during a combustion of limestone in a PFR lime kiln comprising at least two vertical shafts which are connected to each other by means of a crossover channel, wherein each shaft comprises a burning system arranged to produce heat for the combustion of the limestone, thereby producing exhaust gas comprising dust and NOx, the method comprising steps of:

• step 1:
• flowing of the exhaust gas comprising dust and NOx from the PFR lime kiln through a dust treatment system, thereby reducing the dust present in the exhaust gas;
• step 2:
• flowing of the exhaust gas from the dust treatment system to an SCR system, in order to reduce an amount of NOx in the exhaust gas,
• step 3:
• flowing of a mixture of exhaust gas and reducing agent to and through a catalyst, thereby reducing the NOx present in the mixture to dinitrogen (N2) and water vapour (H2O),
• wherein step 2 comprises the step of flowing of the exhaust gas from the dust treatment system to a catalyst which operates at a temperature between 150° C. and 160° C., through a duct which connects the dust treatment system with the catalyst, and simultaneously injecting a reducing agent in the exhaust gas using one or more injection lances and mixing of the exhaust gas with the reducing agent.