In March 2010, ZE PAK SA embarked on the construction of a new biomass-fired fluidized bed boiler (K 12) with a capacity of 154 MW_t (55 MW) at the Konin power station. Biomass being envisioned as the primary future fuel for this power plant, biomass unloading and storage facilities will also be built.

The aim of this project is to minimize the environmental impact of the power plants by using renewable sources to produce electricity: “green” energy from biomass.

The fuel burnt by the boiler will be 100% biomass: 80% wood biomass and 20% agricultural biomass. The resulting pollutant emissions will be within the permitted limits:

• NO_x 3, SO₂3, dust3
• The project is scheduled to be completed by mid-2012.
• Key facts on the progress of the project

Stage IV of the construction of the main steel structure of the boiler and the boiler house has been completed and the installation of the lightweight cladding of the roof and walls of the boiler house has begun. As far as the pressure and mechanical parts are concerned, the boiler drum has been assembled, whereas the assembly of the combustion chamber, the left and right separators, the economizer and the steam heater, the tubular air heater and air fans is in progress.

The reinforced concrete part of the communication pylon has been completed, as have the reinforced concrete and masonry works on the station service switch house building, the foundation for the exhaust gas duct and the cable tunnel. Preparatory works on the assembly of the lightweight cladding of the switching station have begun, and reinforced concrete works on the aboveground part of the compressor building are continuing. In February 2011, the installation of the lightweight cladding of the switching station and stage V of construction of the steel structure (i.e. the biomass bay) began. Also, the construction of an ammonia water storehouse and unloading station commenced. On 9 February 2011, Foster Wheeler Energia Polska (general contractor for the project) started to erect one of the major elements of the project: a 100-metre flue stack. In contrast to existing structures of this type, the new stack at Konin is made of steel rather than concrete, and its diameter is over 3 metres. The assembly of the stack was completed on 18 February 2011.  In March 2011, work continued on the pressure and mechanical parts of the boiler. The installation of fire safety and fire alarm systems and the cable ways of the lighting system also continued. In addition, reinforced concrete works on the ammonia storage building and unloading station and the unloading yard of the ash unloading station were completed, and the compressor hall was protected with oil-resistant coating. The construction of the biomass storage and transportation facilities started in the same month. In addition to site preparation, underground services were being built, as were the biomass preparation building and the open storage yard for wood biomass. The assembly of a six-section switch room at the zero level of boiler-side biomass tanks, the electrostatic precipitator and of the flue gas recirculation fan started in the second quarter of 2011.

On 10 May 2011, the boiler being built at Konin for the new power unit designed to burn wood and agricultural biomass underwent pressure tests. The procedure is subject to strict regulations applicable to the construction of all kinds of pressure vessels. In this case, the relevant standard is that for water-tube boilers, which is harmonized with the relevant directive and the associated guidelines. The tests were carried out by the Ostrów Wielkopolski Branch of the Polish Technical Inspection Office (UDT). The tests are a major milestone as they confirm the correctness of the entire boiler installation, the strength of all parts and, most importantly, the strength of all welded joints. The boiler drum had undergone tests at the manufacturer’s plant as part of the conformity assessment, whereas the connection between the drum and the entire remainder of the boiler, which is a very large assembly, was tested at the site where the boiler will actually be operated. The tests were successful.

While the work on the boiler itself continued, the construction of biomass storage and transport facilities began in May 2011.

Wood biomass storage silos, with a total capacity of 8000 m³, are currently being built to hold fuel for the new power unit. At the same time preparations are in progress for the construction of 6000 m³ and 1000 m³ silos for the storage of agricultural biomass.

External retaining walls were built at the open wood biomass storage yard and the construction of the concrete surface of the yard began.

Diaphragm walls for the wood and agricultural biomass unloading station, the sampling station and the pumping station as well as the barrettes for the transfer tower of the air belt conveyor line were built, and soil began to be excavated from the diaphragm wall cavities.

The reinforced concrete frames of the wood and agricultural biomass preparation building were completed, as were all base stage works on the sampling station building with a system of weighbridges.

Work on the roadways and manoeuvring and parking areas proceeded in July 2011: the base course was strengthened through soil replacement and cement treatment; kerbs and subsurface bedding concrete were laid.

During the same period work continued on the underground infrastructure: potable and fire water systems, industrial wastewater and storm water systems (including a 500 m³ storm water holding tank).

Work on boiler K-12

The construction of the biomass storage and transport facilities proceeded in parallel with further assembly work on the boiler house building: secondary platforms, process pipeline and duct supports were installed, and finishing works were carried out. Work also continued on the power inverter building and on the steelwork for the ash unloading station.