Emission from Estonian oil shale power plants

Flue gas emissions from pulverized oil shale fired boilers of Estonian and Baltic power plants have been studied. The concentrations of NOx, CO, CxHy, HCI, Hf and polycyclic aromatic hydrocarbons in flue gases have been found to be relatively low and acceptable according to German emission limits, for instance. Desulphurization degree of flue gases by SO2 absorption with ash has been found to vary defending on boiler type and operation conditions. In spite of significant sulphur capture (average values for different boilers in the range between 68 and 77 % of the initial sulphur content of the fuel), SO2 concentrations in flue gases remain still very high (up to 2600 mg/m3, 10% O2). Very high concentrations of particles, especially at Estonian Power Plant (up o 6250 mg/m3, 10 % 02) have been detected. Heavy metal emissions were too high by the reason of particle control insufficiency as well. Yearly emission estimates of this study support the former Estonian ones within the range of 10-15 %. (author)