Liquefied natural gas (LNG) currently plays a small, but nevertheless important, role in Hafslund Heat's district heat production. In 2015, the LNG consumption accounted for 0.5 per cent of the input energy in the district heat production in Oslo. LNG is used for peak loads on the very coldest days, but also as fuel during start-up of boilers based on other fuels.
On Wednesday 21 December, a tank truck arrived at the Haraldrud heating plant with 20 tonnes of liquefied bio gas (LBG) from Skangas AS.
"This is our first delivery ever of liquefied bio gas in Norway. The fact that Hafslund Heat now wants to use liquefied bio gas directly in its unmodified LNG plant, shows that investments in infrastructure linked to natural gas and bio gas is the right way to go green. The infrastructure may be used for both the most environmentally friendly of the fossil fuel; namely natural gas, as well as bio gas, which is 100 per cent renewable, without any further modifications," says Halvar Rommetvedt in Skangas.
Bio gas has been established in the transportation sector, and liquefied bio gas may be used without any adaptations in Hafslund's district heating plants that currently use natural gas. By replacing natural gas with bio gas, Hafslund Heat will reduce the CO2 emissions from the Haraldrud heating plant even further.
The LBG market is not yet mature, and the gas is currently priced higher than alternative energy sources such as wood pellets, fossil oil and bio oil.
"As part of the effort to find new suitable fuels that are renewable, we must look at alternatives which are very flexible, to ensure we will be able to cover the fluctuating heating needs in Oslo at any given time in the best possible manner. This is the reason why we are now testing a delivery of liquefied bio gas in cooperation with Skangas. Liquefied bio gas is still somewhat expensive, the market is not mature and we are a challenging customer as our needs are unpredictable. But in order to secure peak load sources with high delivery security that are both environmentally friendly and makes economic sense, we are now evaluating liquefied bio gas, which is renewable and generates no carbon emissions," says Eirik F. Tandberg, Senior Vice President of Hafslund Heat.
"It is also a factor that we have a fully functional gas plant that now runs on liquefied natural gas and may run on liquefied bio gas without any major interventions provided the test goes as expected," concludes Tandberg.
What is LBG
LBG is an abbreviation for Liquefied Bio Gas. This product is similar to liquefied natural gas (LNG). Bio gas is produced from food waste/organic waste in digester tanks (bioreactors) where methane gas is generated. By passing this gas through a purification process, it is upgraded to 97 (+-1%) per cent methane. The gas is delivered liquefied as a cold liquid (LBG) at a temperature of minus 150-170 oC.