Section C Ι Asset Optimisation & Environmental Protection

Thursday, 22 September 2016, 16:15-16:45h/C05

Converting CFB boilers from coal to 100% biomass combustion

Jan Žižka and Ludvík Pavlík, ČEZ Inženýring, s.r.o., Czech Republic; Hynek Lang, ČEZ, a.s., Czech Republic

With the aim of utilization of renewable resources and increase their stake in fuel mix as a part of this process is usage biomass instead of coal in coal plants in the fleet of ČEZ,a .s.. After several trials in different types oc coal boilers (pulverised coal, CFB and grate boilers) with biomass co-combustion it was decided to enlarge capacity of biomass combustion by converting /reconstruction of two CFB at two sites (Power plant Poříčí and Power Plant Hodonín) to 100% biomass burning units.

The decision was based on legislation of the Czech republic, which supports electricity generation from biomass in different price levels depending on type of biomass and type of combustion in power plant. The highest subsidy receives biomass with no other utilization as plant crops and lowest subsidy receives biomass, which can be used in other industries as saw dust. The biggest support receives 100 % combustion of biomass and co-combustion is supported in minimum level.

Power plant Poříčí is located in northern part of Bohemia ansd operates two of CFB with steam output 250 t/hour. Power plant Hodonín is located in southern part of Moravia and operates two CFB with steam output 175 t/hour. Both power plants deliver heat to cities and villages close to power plants. Both projects consist from technological modification of one boiler from two boilers finished in 2010 (in Power plant Hodonín) and 2012 (in Power plant Poříčí) mainly in area of transportation logistics, storage and transport from storage yard to the boiler furnace (new screw lines).

These two reconstruction projects enable to generate electricity from biomass in level of 325 MWh in 2015 ( 117 MWh in Power plant Poříčí and 208 MWh in Power plant Hodonín) what means 98 % of electricity from biomass in whole CEZ,a .s.fleet and cca 400 000 t of burned biomass which is delivered mainly from suppliers from the Czech republic.