Pienhiukkaspäästöt ja niiden vähentä mismahdollisuudet Suomessa. Kasvihuonekaasupä̈astöjen rajoittamisen vaikutukset

In this study, new measuring and research results from combustion-based primary fine particles in Finland were gathered up in order to calculate the emission factors (PM2.5 and PM1). Also the effects of particle separation devices on fine particle emissions, and some emission reduction costs were evaluated. The fine particle data modules were then added to VTT's national energy system model TIMES that has been developed under the IEA ETSAP co-operation. With TIMES model, cost-efficient emission reduction can be evaluated, and the simultaneous changes occurring in the emissions of other air pollutants can be observed. The focus has been especially on the nationally important fuels like wood, peat, and waste derived fuels in mixed fuel combustion. Knowledge of fine particle emissions from different processes has been combined to energy system modelling and to scenario studies on how the Finnish energy production and industrial system will be changing due to commitments of the first and assumed following Kyoto periods. In large-scale boilers the specific emissions of PM2.5 fine particles are even less than hundredth part of the emissions of small-scale (10-50 kW) boilers, i.e. 0.5-50 mg/MJ compared to 50-600 mg/MJ. The specific emissions of fine particles depend most of all on particle separation device(s) used. The used fuel or combustion technique does not have as great influence. The most effective separation device for fine particles is fabric filter. Recent measurements show that after fabric filter the share of PM1 in flue gas is only 1-10% of the total particle mass that is mainly composed of coarse particles/material released from filter or from exhaust gas duct. In addition, collecting efficiencies as well as investment and operating costs of particle separation devices were roughly calculated in this study. PM2.5 fine particle emissions are reduced 15-21% from year 2002 to 2010, and 30-38% till year 2020 in different scenarios calculated, despite the fact that primary energy consumption rises clearly in all the scenarios considered. Reducing greenhouse gas emissions speeds up fine particle emission reduction. Additional use of bioenergy will mainly take place in heat and power plants where fine particle emissions of burning wood don't diverge significantly from emissions from fossil fuels or peat because of efficient particle separation devices, as electrostatic precipitator and fabric filter, used. Emission trading of carbon dioxide has indirect impact on particle emissions through the price of emission allowances. If the price remains low, it's cheaper to buy plenty of emission allowances to Finland in which case the volume of energy production remains at high level and the amount of particle emissions till 2015 is closely-based to base scenario emissions. At the higher prices of CO₂ emission allowances, the progress of particle emissions is more like that in the Kyoto scenario basing on national actions to reduce greenhouse gases, and after the first Kyoto period remains already lower. In the Renewable Energy Sources (UEO) scenario, the great increase of small-scale wood burning leads to slower decrease of particle emissions, but the effect on the total emissions is still rather low.