PINA S.A has in Fuentes (Cuenca) a factory where particle boards are produced. In this factory, dust and bark (biomass) are produced as wastes. Bark was burned in an existing thermal oil boiler while dust was burned in existing dryers.
With the aim to improve factory’s competitiveness and due to the fact that not all generated biomass could be used, it was decided to install a cogeneration plant of 22.9 MW in combined cycle (gas turbine of 19.4MW and steam turbine of 3.5MW) and a simple cycle biomass plant, where 4 MW were generated.
The combined cycle cogeneration plant can supply all thermal demand of the factory (3.4 MWt of thermal oil and 13.1 MW of hot gases to the dryers). Exhaust gases, that are not used to produce thermal oil or sent to the dryers, are sent to a heat recovery steam generator where 18.8 t/h of superheated steam (41.5 bar(a) and 400ºC) are produced for heating condensates coming from the steam turbine of the biomass plant and from the combined cycle steam turbine.
The biomass plant (its fuels were bark and dust) burns the fuel that no longer has to be used to produce thermal oil and hot gases for dryers, in a boiler to produce 21,1 t/h of superheated steam (41.5 bar(a) and 400ºC) that is send to a steam turbine to produce 4 MW.
The bark is transported, from the storage area to the biomass boiler, through a drive system with redler conveyors. With regard to dust, it is transported, from storage silos to the biomass boiler, by a pneumatic suspension system.
As bark and dust are two fuels with different characteristics, they are burned at different points of the productive process and also in different conditions. Bark is burned in a grate firebox combustion chamber and dust is burned in a separate combustion chamber with an specific burner.
The biomass boiler is prepared to operate under the following conditions:
- Using only dust to generate all steam demand
- Using only bark to generate all steam demand
- Using 60% dust and 40% bark
- Using 40% dust and 60% bark
- Using 75% dust and 25% bark
Client: PINA S.A.
Power Range: from 10 to 25 MW
Fuel: Natural Gas