The Thermal Cogeneration Plant is authorized to operate in accordance with the provisions of the Integrated Environmental Authorization (AIA) DEC-MIN-0000085 issued on 11/03/2021 by Ministry of Ecological Transition .

The authorized limits they are equal to 40 mg/Nm3 for NOx and 30 mg/Nm3 for CO; in addition, the Decree of the Ministry of Ecological Transition also reports quantitative emission limits in absolute value equal to 350t/year for NOx and 250t/year for CO. The concentrations must refer to the flow rate of the dry normalized fumes reported at an oxygen content of 15%. 

Monthly emission data is communicated to ARPA Sicily.

We mean hours of normal operation the number of hours of operation of the production process, with the exclusion of start-up and shutdown periods and breakdown periods unless otherwise specified by the regulations or in the authorization phase.

We mean hourly average the average value processed on the elementary data available, ie on the percentage of the number of valid elementary measurements acquired, compared to the number of theoretically acquired values ​​within the hour and relating to hours of normal operation. This data must be invalidated if the availability of elementary data is less to 70%.

daily average is the average value processed on the elementary data available for the day. This data must be invalidated if the availability of elementary data is less than 70%.

monthly average is the arithmetic average of the valid hourly average values ​​recorded during the month.

annual average is the arithmetic average of the hourly average values ​​recorded over the year.

O 2 % : is the percentage by volume of O 2 in the fumes detected by the oxygen meter.
NO x : content of NO x , such as NO x = NO + NO 2 in the fumes of discharge expressed in mg / Nm 3 . If the concentration of NO 2 is less than or equal to 5% of the total concentration of NO x (NO x = NO + NO 2 ), the measurement of only monoxide (NO). In this case, the concentration of nitrogen oxides NO x is obtained by means of the following calculation NO x = NO / 0.95.

CO : carbon monoxide content in exhaust fumes, expressed as mg / Nm 3 .

All concentrations must refer to a reference oxygen content of 15%, in accordance with the Resolution Authorization, as follows

where:

Ec = Corrected emission
Em = Measured emission
O 2 r = Reference oxygen (15%)
O 2 m = Oxygen measured

Operating state:

Plant in start-up: a plant is considered in the start-up phase, unless otherwise specified legislation or authorization, when it is gradually put into service until the technical minimum is exceeded.

System stopped (or stopping phase): a system is considered to be stopped when, for various reasons, it is (gradually) put out of service and excluded from the production cycle. Unless otherwise provided by law or authorization the shutdown phase begins below the technical minimum.

System Stopped: the system is considered to be stopped when the gas turbine unit is not supplied with fuel.

Minimum Technical: is the minimum process load compatible with the operation of the plant in conditions of regime (Normal operation).

System running: system in normal operation.

Smoke flow rate: calculated on the basis of the combustion products, the flow rate of the natural gas consumed and its composition.

Fumes Temperature: expresses the temperature value of the combustion products at the outlet, measured with a probe positioned at the end of the chimney.

CO (t) and NO x (t): expresses the total quantity of emissions in tons, calculated on the basis the specific concentrations and the flow rate of dry fumes leaving the chimney. This capacity is calculated on the basis of combustion products, the flow rate of the consumed natural gas and its composition.

Power generated electricity: power produced by the plant in operation expressed as electrical MW.

SME: Continuous Monitoring of Emissions.