Cost-Effective Abatement of Acidifying Emissions with Flue Gas Cleaning Vs. Fuel Switching in Finland

Acidifying emissions from energy production and industry have decreased considerably during the last two decades in Finland. Especially the emissions of sulphur dioxide have dropped sharply with 85% in 1980-1998, although the energy use has increased 30% during the same period. The reduction has occurred through two mechanisms: by replacing the combustion of heavy fuel oil with cleaner energy carriers, and by direct emission reduction controls, e.g. flue gas desulphurization. In this study the Finnish cost curves for SO₂ and NO_x were first calculated to produce a consistent comprehensive view on further emission reduction costs and potentials. The data on technical and cost-related parameters were based on actual national experiences from power plants and industry. Most of the cost-efficient sulphur emission controls were already in use. For NO_x, a large share of further reduction potential still remained. Second, a case on the emission reductions and costs for fuel switching in a 205 MW_th peat power plant of Tampere Power Utility in Finland was studied. Fuel switching to natural gas was found less cost-efficient in SO₂ and NO_X emission reduction when compared to flue gas cleaning techniques. The findings provided new information on fuel switching as an alternative potential reduction measure, which is not considered in international assessments. Keywords: air, cost curves, emissions, fuel switching, reduction costs