Bio gas facility / Upgrade facility
Skellefteå Municipality – LNG as back-up
Skellefteå Municipality started its own bio gas plant/upgraded plant in 2007 and has achieved the maximum capacity of the upgraded facility. Before an expansion to double the factory capacity, the municipality decided to invest in an LNG facility to increase gas delivery safety to local traffic and the municipality’s own cars that are gas-driven. In addition to the filling station at the plant there are two additional filling stations where private customer’s gas-powered vehicles can also refuel.
Production of bio gasBiogas production is processed in two separate chambers, a mesophilic wastewater treatment, and a thermophilic waste chamber. The raw gas is thereafter purified to an approved vehicle gas quality (97% methane).
Today, this plant primarily produces vehicle gas for the local bus/bus service, but in Skellefteå the private market has also grown on gas-powered vehicles. In addtion a smaller part of the gas capacity is used for energy and heating.
In total, approximately 1.1 million Nm3 of bio gas was produced from the facility in 2015, production is steadily increasing to produce more than 2 million Nm3 at full capacity. An expansion to the upgraded facility is scheduled for completion by the end of June / July 2018.
LNG as backupDue to plant maintenance and upgrade stoppages as well as capacity challenges the municipality identified the need for a back-up solution. As natural gas and bio gas are basically the same type of gas (methane) it is fully interchangeable and possible to mix the gases.
However, the municipality has chosen to separate the biogas from the natural gas for reducing the risk of flaring of biogas, but with the possibility of utilizing the installations as dispensers and high-pressure bearings for different operators.
Since the municipality has separate systems, they can easily monitor and measure the proportion of natural gas via measurement of the supplied amount of gas to trucks and dispensers.
Skellefteå Municipality consumes approximately 3-5 GWh/year of natural gas depending on how much bio gas they produce.
Monitoring the LNG facilityMonitoring of the LNG tank is done by the staff at the bio gas plant. Usually, the tank is filled up approximately every 10 days. The natural gas is delivered in liquid form (LNG) to a 100 m3 cryo-tank which is 20 m high.
In addition to the tank, the LNG plant has a cryopump and high-pressure evaporator with a capacity of 650 Nm3/h.
“Thanks to Natural Gas/LNG the municipality can ensure operation of public transport and other vehicles in Skellefteå”
Peter Edlund, Skellefteå Municipality
Facts about the Natural Gas facility
About 10 km from the city centre
Site manager: Peter Edlund
Natural gas installation since 2007
Benefits from LNG/Natural gas
Ensures the operation of the municipalities 39 vehicles that are gas-powered.
Gives an opportunity to strengthen the infrastructure of filling stations in Skellefteå
3 filling stations are always in operation thanks to back-up.
Natural gas and bio gas are basically the same gas, mainly methane. Therefore, it can be blended without any problems.
The LNG Facility
For more information see
website Skellefteå Kommun