VamBio Oy – biogas from Vampula biogas plant in Huittinen

Case Study Biogas

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Greenhouse gas emissionsThe energy content of a cubic metre of methane corresponds to a

litre of light fuel oil. At full capacity the biogas production is about

2.6 million cubic meters per year. This naturally produced renewable

energy can replace more than 45 tons of fossil fuels locally and

produce bio electricity about 5000MWh/a.

SummaryVamBio Oy is a modern biogas plant with an excellent location.

It is well designed, and it has several smart details. The structure

of the ownership follows the instruction stated in the policy of the

government, i.e. a rather large biogas plant with several shareholders.

The feed-in tariff did not exist when the plant was build. However,

the plant seems to be profitable even without the tariff, as the figures

reveal. In the background of this are other revenue streams from the

selling of raw materials, heat and electricity, and also from fertilizers

and soil treatment substances. The selling of the surplus heat is a

problem in several plans, but Vambio Oy has suggested that this is

not insurmountable.

AuthorMarkku Kallio

markku.kallio@vtt.fi

VTT Technical research centre of Finland

Source of the text Kaisa Suvilampi

www.agriforenergy.com www.vtt.fi

The sole responsibility for the content of this folder lies with the authors. It does not necessarily reflect the opinion of the European Communities.

The European Commission is not responsible for any use that may be made of the information contained therein.

InfoVamBio Oy

Toimitusjohtaja

Kaisa Suvilampi

Wahreninkatu 11

30100 Forssa

Puh. 050 525 4222

Kaisa.Suvilampi@vambio.fi

InfoVamBio Oy

Managing director

Kaisa Suvilampi

Wahreninkatu 11

FI-30100 Forssa

Tel. +358 (0)50 525 4222

CompanyThe biogas plant is located in Vampula village in Huittinen. The

plant is well situated at a highway intersection and also between

two large pig farms that are about 700 metres from the plant.

The present output of the plant is approx. 60,000 t/a.

The biogas plant of VamBio Oy started in Vampula village,

Huittinen in March 2010. The investment in the plant was

launched in May 2009. VamBio’s plant is a large-scale co-

processing plant with a biogas energy output of more than 3 MW.

On top of the actual investments in the biogas plant, VamBio Oy

has built up a local energy network delivering bioenergy upgraded

from renewable waste materials to the local industry, to primary

production and to a regional electricity company.

OwnershipVamBio Oy is a private company owned by four persons and

a technology company Watrec Oy. Watrec Oy designed and

constructed the plant.

Description of the processManure, municipal sludge and other by-products are received

in a closed loop reception pool. The reception hall and the

reception pool are under-pressurized. Removed air is conducted

into the processing system for malodorous gases. Washing of the

transport vehicles is also carried out in the reception facilities.

After receiving, the raw materials are crushed to a particle

size of less than 12 mm with a crusher pump, and diluted to

a consistency of approximately 12%. The materials are then

pumped into a pre-reactor, from where they continue through

heat exchangers into hygienisation units. There the temperature

of the material is raised to 70 °C for one hour. The hygienisation

units work as parallel batch processes, so the feed of the

biological material into the process is not interrupted.

The slurry is pumped through heat exchangers into the actual

biogas reactor, which is a continuous, mesophilic process

operating at a temperature of 35-40 °C. The retention time of the

sludge in the reactor exceeds 21 days. The CH4 concentration

of the biogas is in order of 65-70% of the gases. The plant’s

energy output is more than 3 MW, and it has two parallel 2,700

m3 biogas reactors. In addition, the plant has a post-gasification

reactor, into which the slurry is led from the actual biogas

reactors.

The biogas of the plant is recovered from both the main reactors

and the pre- and post-reactors. The biogas contains small

amounts of the hydrogen sulphide (approximately 0.1-0.3%),

which is removed before use.

The capacity of the gas storage was designed to be sufficient

to handle the volume of about 4 hours of gas production. The

biogas can now be used in a CHP unit or in industry.

The remaining digested sludge of the biogas production is led

either into the producer’s own fertilizer storage or directly to

farms for exploitation. In addition, the digested sludge can be

led into a water separator. It is possible to separate two nutrient

fractions from the digested sludge: i.e. a phosphorus-rich dry

ingredients, which contain about 80-90% of the phosphorus of

the sludge, and reject water (liquid nitrogen), corresponding to

approximately 85-90% of the total flow of the slurry. The reject

water contains approximately 90% of the ammonium-nitrogen of

the sludge, and about 80% of the total nitrogen of the sludge.

The dry-matter will be delivered to the end-users and the reject

water is returned to the beginning of the process for the dilution

of raw materials. Utilization of the liquid nitrogen on arable land

is prohibited by current legislation when the raw material used is

sewage sludge. The legislation is contradictory and it is expected

to change in the near future.

The CHP unitThe company’s own CHP plant generates electricity from biogas

at VamBio Oy’s plant, with a maximum output of about 1MW.

Heat is generated in addition to electricity. The CHP plant consists

of two units, a Perkins 577 kWe and 880 kWth, and a Man 360

kWe and 473 kWth. Before the gas is used as a fuel in the CHP

units, the hydrogen sulphide has to be removed from the biogas.

The surplus power remaining after the plant’s own consumption

is delivered through Sallila Energy Oy into the national grid,

and the thermal energy is supplied through the district heating

network to the nearby pig farming companies. At the end 2010

these companies switched over completely from oil heating to

biogas-based “local heating”.

Biogas to industryVampula lime plant is the first biogas-using factory in the mining

industry. In late November 2010 the manufacturing plant of

Vampula lime, Nordkalk Oy Ab, was changed from light fuel oil

mainly to the use of biogas. The aim is that at least 70% of the

energy needed for drying of the limestone would be replaced by

renewable bioenergy.

Fertilizer products Slurrified fertilizer products are formed in the manufacturing

process and can be supplied to farmers. The spreading of the

fertilizer product can be done using sludge-spreading equipment.

In addition, the company also produces soil fertilizers suitable

for spreading on arable land. The spreading be done with the

spreading device used for dry manure.

The homogeneity and the hygiene of the fertilizer products is

monitored in the quality control. The production of the fertilizer

is controlled by Evira.

Raw materialsVambio Oy provides waste management services to municipalities,

the food industry and primary production. VamBio Oy produces

clean bio-energy and fertilizer products to be returned to primary

production from the biosludges of the municipalities, from

livestock, and from the side streams of slaughterhouses and

the food processing industry in accordance with the fertilizer

regulation act.

Relative distribution of raw materials and the amount of

produced bioenergy from different raw material sources.

The by-products from agriculture include 20,000 t of liquid

manure, 2,500 tons of dry manure, and 2,500 t biomass from

plant cultivation. The by-products of municipal sewage sludge

amount to 20,000 t. The above figures indicate that a 60,000

t/a bio-energy plant can produce 20,875 MWh/a of bioenergy, of

which own use accounts for 2,500 MWh/a.

Investment costsThe total cost of the plant investment was about 7 million euros,

including the construction of the energy network (3 km of district

heating lines to the piggery companies and the line from the

biogas plant to the limestone plant, approximately 1.5 km).

The company has received approximately 1.83 million euros

of energy subsidies for the investments from the Ministry of

Employment and the Economy.

Annual economy of the plantVamBio Oy is a private limited company, in which the ownership

is divided between 4 persons and the institution responsible

for the design and construction technology (Watrec Oy). The

company’s turnover is about 2.3 M €, and the operating costs of

the plant are about 1.4 M €.

Schematic diagram of VamBio Oy’s biogas plant in Huittinen