Coal and environmental impact
The less known coal’s characteristic is for sure its environmental friendly quality, according to present laws.
That is particularly true in Italy, where all the coal plants have EMAS certification – the European environmental certification, more severe compared with ISO 14001. These plants excel also according to efficiency, with a productivity of 40% compared with 35% of the European average and with 25% of Continental Europe.
The modern coal plants in Torrevaldaliga has already reached an efficiency rate of 46%, which is only reached in Japan and Denmark in the world.
The investments aimed at cutting pollution follow two lines of action: • The reduction of polluting emissions thanks to increasingly sophisticated systems for the treatment of fumes, including de-sulphurisation and de-nitrification units, plus dust extractors; • The prevention of the formation of polluting emissions at their origin through innovative techniques and processes which improve energy efficiency.
The results of these investments are a rapid and significant reduction of all polluting emissions, achieving the following goals:
- 70% reduction in emissions of sulphur dioxide (SO2) when compared with the rate of 20 years ago. Today sulphur dioxide emissions are equivalent at 100 mg/Nm? Recent legislations have fixed maxima at 200 mg/Nm3;
- Strong reduction in nitrogen oxides (NOx). A first important decrease of nitrogen oxides emissions was registered during the 90s and today they can be valuated at 100 mg/Nm?, a value clearly lower than the one imposed by law (the limit is fixed at 200 mg/Nm3);
- Reduction of dusts emissions: in the 90s they were reduced of 63%, in 2003 another reduction of 75% has been registered. Today dusts amount at around 15 mg/Nm? (the total reduction is not foreseen by the law) while the limit is 30 mg/Nm3;
- 100% recovery of ash and chalk. They can be easily reused for the production of pilling, cement, street paving and for the production of building material.
Moreover in 2000, 10 years before the Kyoto Conference established its objectives, Italian coal plants had reduced carbon anhydride (CO2) emissions of 7,6%. In consideration of Kyoto objectives the Association has ordered a study on CO2 emissions to the Experimental Station for Fuels, Milan, in order to analyse the effective CO2 emissions – during the entire life cycle.
In particular the study compares CO2 coal and gas emissions not only during the combustion, but also in the pre-combustion phases. The comparison of the whole life cycle decrease therefore the distances: the greenhouse gases total emissions would result between 510 and 670 grams of CO2 -equiv./kWh for gas (420 if the gas would be produced in Italy) and between 780 and 910 grams of CO2 -equiv./kWh for coal.
In fact, the pre-combustion data underline a higher level of CO2 emission for gas, with peaks of 288 gr of CO2 -equiv./kWh in the Russian gas case.
While, for coal, the emission recorded are equal to 127 gr of CO2-equiv./kWh in the case of extractions from underground mines and just 127 gr of CO2-equiv./kWh for mines on the surface.