Conversion of a coal-fired power boiler: Green electricity through biomass combustion. Experience from EC Białystok S.A. Finnish-Polish energy seminar Warsaw, September 17, 2010 Kari Kupiainen Roman Szerszeń

© Metso 2 Reasons for the conversion Production of green electricity Reduction of SO 2 and NO x emissions Utilization of new fuels in power generation CO 2 control The existing combustion technology needed to be modernized in order to meet the requirements involved in above targets

© Metso Conversion to BFB boiler Normal scope of supply: Replace lower furnace with fluidized bed Replace fuel feeding Add bottom ash removal Add start-up burner(s) Add fluidizing air fan and ducting Add re-circulation flue gas fan and ducting Modify over-fire air system E&I modification New DCS Civil works 3

© Metso BFB conversion benefits Better fuel flexibility Improved availability Reduced maintenance Easier operation Lower emissions Better efficiency Typically 30-60% of the price of a new boiler plant 4

© Metso Elektrociepłownia Białystok S.A. One of the largest companies and the biggest producer of green electricity in north-eastern Poland

© Metso EC Białystok S.A. Biomass project scheme

© Metso HYBEX boiler Bubbling Fluidized Bed (BFB) technology BFB Boiler Conversion Elektrociepłownia Białystok S.A Białystok Poland Converted Steam75 MW th 105 t/h, peak 120 t/h, 138 bar 540 °C FuelsWood chips, forest residue, willow, grain waste, coal Start-up2008 7

© Metso 8 Fuels Biomass - wood chips % - forest residue (green) 0-20 % - forest residue(brown) 0-20 % - willow 0-10 % - green wastes 0-2 % Coal - coal burners were preserved Light oil - for boiler start-up

© Metso Achieved ecological effect ReductionActual values - Mg in a year SO 2 emission277 NOx emission142 Dust17 Furnace waste8.400,05 CO

© Metso Full-scale agro combustion demonstration in EC Białystok (after some months commercial operation, autumn 2009) Motivation - Why ? According to Polish Energy Law the wet mass share of energy crops or agricultural origin having biomass has to be at least 20% 10

© Metso Tested fuels: woody biomass, oat seed (unsuitable for food purposes), sunflower seed hulls pellets 11

© Metso Phosphorus and potassium 12

© Metso Sulfur and chlorine 13

© Metso Key observations of the test Fluidized bed agglomeration lowering the bed temperature below first melting temperature of alkali-calcium-phosphate-silicate melt. Typically it means operation below 750°C. Furnace slagging and fouling of superheater or economizer surfaces proper sootblower location and frequency combustion conditions adjustments. 14

© Metso Key observations of the test High temperature corrosion Design Material selection Sulphur addition if needed Emissions Minor increase in NO X level 15

© Metso Happy Operator of Metso’s BFB boiler 16