Konin CHP Biomass

In June 2012, a biomass-fired boiler (unit) was commissioned in the Konin Power Plant. The unit is located in the central part of the industrial area of the Konin Power Plant, i.e. about 7 km north of the city of Konin. The target of the investment was to meet the stringent emission standards and to build a generating unit that would be fully environmentally friendly. It was the first step of ZE PAK SA on the path of ecological transformation aimed at the gradual departure of the Company from fossil fuel – lignite – in favour of renewable energy sources.

The biomass-fired boiler was equipped with a circulating fluidized bed (CFB), it was built in place of the former lignite-fired boiler.

The financial commitment of the European Bank for Reconstruction and Development (EBRD) towards PAK should be emphasized, which was related to the completion of the construction of a new biomass-fired boiler, implemented by Foster Wheeler.

The project involved the construction of a biomass combustion system and upgrade of the existing facilities and installations.

The construction of a biomass-fired boiler ensured compliance of the Konin Power Plant with the strategic approach of the European Union regarding the environmental impact of the power plant in accordance with 2001/80/EC LCP and 2004/8/EC Directives.

The new boiler partially uses the existing components of the old boiler infrastructure. Nevertheless, the main process parts and auxiliary systems were built or modernized as part of the new project. Its implementation included:

• Construction of a boiler room along with the assembly of a new biomass-fired fluidized bed boiler with a circulating fluidized bed (CFB). The boiler has a capacity of 154 MW and a steam production capacity is 215 t/h. At the same time, buildings and process auxiliary systems were modernized.
• Construction of a biomass storage facility and a system used to collect its delivery.
• Modernization of the turbine, biomass processing building, water cooling system and plant laboratory.
• Reconstruction of the infrastructure located on the plant premises, including underground systems, warehouses and manoeuvring areas.
• Modernization of oil and combustion waste management facilities.

What is a fluidized bed boiler (CFB)?

The fluidization process used in boilers consists of blowing air through a bed resting on the bottom of the combustion chamber. Depending on the speed of the air stream, fluidized bed boilers can be divided into two main types: stationary (bubbling) boilers, in which the air flow velocity is 2-3 m/s, and fluidized bed boilers with a circulating bed, in which the speed air flow is approx. 5 m/s.

The bed in fluidized bed boilers consists of a mass of inert, fine particles suspended in a gas stream. In case of combustion of biomass, the added sand particles are primarily used to form the bed.

The boilers are constructed in such a way so they could meet stringent air emissions standards. The strength of turbulence and proper mixing of fuel (biomass) in such beds ensure high combustion efficiency. In such cases, in order to obtain the lowest possible emission of nitrogen oxides (guaranteeing compliance with emission standards), the boiler is equipped with a circulating fluidized bed with a furnace equipped with an appropriate nozzle system.

To ensure the desired level of nitrogen oxide emissions, the boiler is equipped with ammonia water injection system, cold exhaust gas recirculation system and appropriate secondary air dosage system. Additional benefits include the possibility of using fuels such as biomass, which are difficult to be combusted in traditional boiler systems, and a relatively small amount of residue in the form of ashes.

Biomass

The main fuel used in the Konin Power Plant is biomass consisting of a mixture of wood biomass and agricultural origin mixture. The percentage of agricultural biomass in the total amount of biomass burned in the plant is about 20%. The basic fuel is wood biomass in the form of chips and sawdust from coniferous and deciduous trees, wooden pallets and bark in the form of chips.

ZE PAK uses biofuels produced from, the so-called, certified biomass manufactured by external companies and supplied by external suppliers.

What are the benefits of the project?

The main environmental benefits of the Konin CHP plant modernization project, including the assembly of the biomass-fired boiler compared to the old lignite-fired boilers:

• Emissions of sulphur dioxide reduced by approx. 1200 tons/year, nitric oxide by approx. 1000 tons/year and particles of matter by approx. 100 tons/year.
• CO2 emissions are considered environmentally neutral because they are produced in the biomass combustion process (the amount of CO2 emitted is equal to the amount of CO2 consumed during the life of the plants/trees)
• General improvement of air quality despite higher energy production
• Lowering acid deposition in the environment owing to lower SO2 or NOx emissions,
• Reduction of employees' exposure to the presence of elevated levels of dust and gases resulting in a lower risk of occupational diseases
• Replacement of fossil fuels (lignite) with "green" renewable fuel (biomass)

On May 10, 2012, the new power unit was synchronized with the National Power Grid. In May, the adjustment run was also carried out, followed by 720 hours of trial operation of the entire power unit. On June 29, 2012, the ZE PAK SA unit was ceremonially put into service, and after the trial run its full commercial operation was commenced.