Start up results from a specialized flue gas cleaning facility in a power station using refinery residues

In eastern Germany STEAG--the biggest German IPP--has erected a power plant consisting of three combustion lines burning oil distillation residues from the new Mider refinery to provide the refinery with power, steam, water and compressed air. Each of the three flue gas cleaning lines consists of a high dust SCR-system, quench, wet electrostatic precipitator, scrubber, steam reheater and ID-fan. Common systems are the storage and handling of the absorbent, the gypsum dewatering and the waste water treatment. The installed high dust SCR system attains the expected NO{sub x}-reduction efficiency and an excellent NO{sub x} outlet distribution and low ammonia slip. After commissioning problems occurred with the wet ESP in all three lines due to improper function of the upstream quenches. Modifications of the quench system have been made which assure a temperature of the flue gas after quench near saturation temperature and correct functioning of the quench and wet ESP. To reduce pressure loss of the absorber concurrent spray nozzles were installed. Strong vibrations of the absorber tower, the connected pipes and the steel structure along with an insufficient SO{sub x} removal efficiency at high inlet concentration were observed. After changing the concurrent operation of the spray nozzles to countermore » current operation the vibrations of the absorber tower became smaller and the removal efficiency achieved the guaranteed value. Problems arose in the waste water treatment plant caused by the high solid concentration of up to 1,000 g/l in the thickener. By diluting the settled sludge with overflow water from the thickener the problems in the waste water treatment plant could be minimized to an acceptable degree. Despite these problems the flue gas cleaning system is in continuous operation and the emission values of flue gas and waste water meet the required standards.« less