Info about biogas

In February 2017, Stormossen’s first refuelling station, Gastor, opened. Our biogas is good and locally produced. When choosing biogas instead of petrol or diesel, acidifying and eutrophic emissions in the form of sulphur and nitrogen are reduced.

Biogas is a 100% renewable fuel. From an environmental perspective, this is a very important feature. According to a study conducted by DENA, Deutsche energi agentur, greenhouse gas emissions are up to 90 percent lower than petrol and diesel.

Our second station will open in 2019 at the ABC Service Station (Runsor), Vaasa. Welcome to refuel with biogas! Gastor vehicle fuel costs 1.45 €/kg, which corresponds to a petrol price of 0.93 € /litre.

Gas is always available as we have an LNG/LBG backup system. Our goal is that in the future there will be at least three gas filling stations in the Vaasa region.

This is how a gas-powered car works

A gas-powered car usually has two fuel tanks, one for vehicle gas and another for petrol or diesel. If the gas runs out, the car will automatically change the fuel system.

If the car is a diesel-gas vehicle, so-called DualFuel, some diesel is always used to ignite the vehicle gas.

The market for used biogas-powered cars is relatively small in Finland compared to Sweden, for example. If you are interested in importing a car from abroad, there are various companies that can help with the practical details. Most car dealers also have new biogas-powered cars in their range.

In addition to Stormossen’s refuelling stations, biogas for refuelling in the region can be found at Jeppo Biogas in Jeppo.

Biogas as vehicle fuel

Biogas is formed when organic material is broken down in an oxygen-free environment with the help of microorganisms. This process forms methane, CH4, and is called anaerobic digestion. The biogas is produced in Stormossen’s reactors and consists of 65 percent methane, the rest being carbon dioxide (CO2) and smaller amounts of other gases.

The carbon dioxide content of the biogas is replaced, as well as the hydrogen sulphide and water, to become vehicle gas consisting of at least 96 percent methane. The methane content of the biogas corresponds to the natural gas imported into Finland. Since biogas is produced from renewable raw materials, it has virtually no greenhouse gas emissions.

A standard cubic metre (Nm³) of methane has a heat value of 9.97 kWh. As a result, vehicle gas with 97 percent methane has an energy content of 9.67 kWh, and when compared to other propellants:

1 Nm³ biomethane 9.7 kWh
1 Nm³ natural gas 10.0 kWh
1 litre of petrol 8.9 kWh
1 litre of diesel 9.8 kWh
1 litre E85 6.6 kWh
1 kg natural gas 13.7 kWh
1 kg biomethane from Gastor 13.5 kWh

Since natural gas also contains other hydrocarbon chains, such as ethane, propane and butane, it has a slightly higher energy content than biogas. This means that natural gas has a higher density than biogas. However, since vehicle gas is sold by the kg, the price and the amount of energy that the consumer receives are virtually the same, regardless of whether the vehicle gas consists of biogas or natural gas.

Sales per kilogram make it easier for the customer, because the car’s consumption meter shows kg/100 km. One kilogram of vehicle gas is equivalent to 1.5 litres of petrol or 2.32 litres of diesel.

From banana peels to biogas

Biowaste and sludge are digested in the two bioreactors buried in the bedrock. In the digestion process, the organic material in the sludge and the biowaste are broken down by microorganisms. This takes place in an acid-free environment for about 20 days at 55C.

Once the biogas in the reactor is ready, it is refined to make it suitable for use as a vehicle gas. This is done by separating the methane gas from the carbon dioxide. After refining, the biogas contains 97 percent methane.

The gas is led via a pipeline to the gas filling station. The pressure is increased by a compressor to a maximum of 300 bar and then the gas is stored in gas cylinders. The gas can now be used to refuel the buses operating in Vaasa or gas-powered vehicles owned by private motorists.

Backup with LNG and LBG

LNG and LBG are both liquid methane, but of different origins. LNG (Liquid Natural Gas) is natural gas that has been converted to liquid form. LBG (Liquid Bio Gas) is biogas that has been converted to liquid form. The methane turns into liquid when cooled to -160 degrees.

LNG and LBG are used to ensure the delivery of vehicle gas to buses, private motorists and companies. If the self-produced gas is not sufficient, LNG or LBG is used as replacement gas. Liquid methane is transported to the plant by tanker and moved to a storage tank at the gas station. The cooled liquid gas is stored at -160 degrees.

The digestion process also produces a digestion residue that is post-composted and mixed with topsoil, sand and lime. Stormossen’s compost earth is suitable for use in gardens and landscaping. It contains both nutrients such as nitrogen and phosphorus and large amounts of organic matter.