Project title: Steam-based cogeneration system with 20 t/h of superheated steam at 40 bar and 400°C fired with wood biomass with a capacity of 3,3 MW.
Investor: Strizivojna Hrast d.o.o.
Location: Strizivojna, Croatia
Construction completion: 2011.

Project description

Reasons for investing:

• Investor is producing electricity in diesel generators because of limited grid capacity
• There is an increased need for electricity due to increased parquet production
• There is sufficient wood residue for a cogeneration plant
• A new grid is being built by HEP in the meantime

Equipment dimensioning:

• Steam boiler fired by biomass 20 t/h, 40 bar, 400°C
• Condensing steam turbine with regulated steam extraction and a heat station 2x3 MW with parameters 90/70°C for wood drying kilns
• Air condenser
• Weekly biomass tank

Enerkon participated in the project by preparing:

• All Cost-benefit analysis and Investment studies
• Tender documentation for the delivery of the main equipment of the cogeneration plant by the "turnkey" model
• Main design
• Detailed design
• As-built documentation

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Project title: Biomass cogeneration 3 MWel
Investor: A&A BIOENERGY VIRO d.o.o.
Location: Virovitica, Croatia
Construction completion: 2019

Project description

Reasons for investing:

• Simultaneous production of electricity and heat from renewable energy sources;
• Thermal energy supply for a company that processes, dries and sells wood, wood products and fuel (biomass);
• Diversification of electricity sources and increasing Croatia’s energy independence level;
• Increasing the share of renewable energy sources in electricity production (CO2 neutrality);

The production of electricity and heat from biomass (wood chips and wood residue) in a cogeneration plant is an example of a complete and sustainable, environmentally friendly way of energy management. Produced thermal energy is used in the technological process of drying in the immediate vicinity of the plant. Thermal energy is used in the dryer of wood chip, the chamber dryer of sawn material, the firewood dryer and for heating of the administrative building and production facilities. All the heat supplied is low temperature, from a heating condenser, whilst the heat consumers are adapted to use such heat. This way, the available amount of heat was increased, the efficiency of the plant was increased, and heat loss was reduced.

Enerkon participated in the project through following activities:

• Development of the plant concept
• Justification analysis of the construction
• Main design
• Detailed design
• Supervision of Mechanical works

Project title: Biomass boiler room with thermal power of 3 MW
Investor: Funda d.o.o.
Location: Zagreb, Croatia
Construction completion: February, 2018

Project description

Reasons for investing:

• High cost of energy for heating – natural gas
• Replacing a fossil fuel with a renewable energy source

Construction of the boiler room was carried out through the ESCO model, which ensures that energy efficiency improvement measures are implemented in public sector buildings without additional spending of budget funds. The reconstruction of the entire boiler room was included in the project with the installation of a new wood biomass boiler - wood chips, as well as the reconstruction of heating substations within the complex.

Results of equipment dimensioning:

• 3 MW hot water boiler, 90/70°C
• Heat accumulator with a volume of 70 m³
• Multi-day biomass tank with a volume of about 250 m³

Enerkon participated in the project through following activities:

• Cost-benefit analysis
• Conceptual solution and equipment dimensioning
• Main design and cost estimate for Public Procurement
• Evaluation of offers
• Detailed design

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Project title: Reconstruction and conversion of a bund wall of heavy fuel oil tank 1000 m³ into a steam boiler room fired by biomass
Investor: Solana Pag d.d.
Location: Pag, Croatia
Construction completion: 2013

Project description

Reasons for investing:

• High production costs of salt per unit of mass and environmental protection reasons (energy expenses and pollution due to the existing heavy oil boiler room)

While comparing various alternatives of energy efficiency improvement, it was concluded that the installation of a biomass steam boiler would be the best solution. Years of monitoring economic indicators after the commissioning of the boiler room showed that the investment was justified. The plant was built in the area of a 1000 m³ bund wall of a heavy oil tank that was dismantled. A steam boiler fired with biomass was installed, with a capacity of 11 t/h of dry saturated steam at a pressure of 11 bar and a temperature of 184°C (8 MW). Type of installed steam boiler is the same as BKG, product of TPK OROMETAL Oroslavje. A daily tank of shredded biomass was built within the plant, from where the biomass is supplied to the boiler via a sliding floor and screw conveyors. The produced dry saturated steam is used by the plant for the production of salt from the sea solution.

Enerkon participated in the project through the following activities:

• Preparation of Cost-benefit analysis of various solutions
• Conceptual design
• Main design
• Detailed design
• Supervision of Mechanical works
• Chief Supervising Engineer

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Project title: Hot water boiler room 1000 kW fired with wood biomass
Investor: Pokupsko Municipality
Location: Pokupsko, Croatia
Construction completion: 10/2015

Project description

Reasons for investing:

• improvement of living conditions for the local community
• withdrawal of non-refundable EU funds for RES projects (IPARD Measure 301)

A hot water boiler room fired with biomass was built, with a thermal power of 1000 kW. A HERZ boiler was installed in the boiler room. Next to the boiler room, there is a daily biomass tank from which biomass is delivered to the boiler via a sliding floor and screw conveyors. A monthly biomass tank that is covered was built within the plant, next to the boiler room, to which shredded biomass is supplied.

Enerkon participated in the project through the following activities:

• Completing the application for EU funds (technical part)
• Preliminary design
• Main design
• Supervision of Mechanical works

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Project title: Biomass boiler room with thermal power of 2 MW
Investor: Zagrebački Holding d.o.o.
Zrinjevac branch
Location: Zagreb, Croatia
Construction completion: February, 2019

Project description

Reasons for investing:

• High cost of fuel used for heating – natural gas
• The issue of tree maintenance waste disposal in the city of Zagreb
• Replacing a fossil fuel with a renewable energy source

The Cost-benefit analysis showed that the investment in a biomass boiler room was extremely favorable due to the high costs of natural gas for heating greenhouses and the affordable biomass that is collected during the year from pruning trees in urban areas.

Results of equipment dimensioning:

• 2 MW hot water boiler, 90/70°C
• Heat accumulator with a volume of 100 m³
• Multi-day biomass tank with a volume of about 175 m³

Enerkon participated in the project through following activities:

• Cost-benefit analysis
• Conceptual solution and equipment dimensioning
• Main design and cost estimate for Public Procurement
• Evaluation of offers
• Detailed design
• Supervision of Mechanical works

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Project title: Wood pellet manufacturing plant
Investor: RST Pellet d.o.o.
Location: Delnice, Croatia
Construction completion: 2019

Project description

Reasons for investing:

• Production of high quality pellets due to market demand 75 000 tons of annual input of biomass as raw material are planned and a production of up to 40 000 tons of finished product-pellet per year. The pellet producing plant and biomass boiler use forest biomass as raw material.
  75 000 tons of biomass per year (with 35% moisture) need to be ensured. About 55 000 tons are used for the production of 40 000 tons of pellets, while the rest is used for boiler needs.

Enerkon participated in the project through following activities:

• Main design
• Detailed design
• Supervision of Mechanical works

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