Technology group Wärtsilä will supply two large-scale biogas upgrading plants to different locations in Denmark. The order was placed by Nature Energy – the world’s leading biomethane company. By injecting biomethane – the end-product of upgraded biogas – into the gas grid, Denmark will be taking an important step towards its stated ambition of becoming a climate-neutral and fossil-free nation. 

The agreement with Wärtsilä dates back to early 2019, although the project was delayed because of permit applications. Production of the upgrading unit has been initiated in the fourth quarter of 2020, when the orders were also included in Wärtsilä’s orderbook. 

Biogas is produced primarily from waste products, such as manure and food waste. When upgraded to biomethane, it can be utilised in the same way as natural gas for heat, powering industrial processes, and as transport fuel. It is a renewable energy solution since the remaining digestate can be sold as bio-fertiliser. Currently, biomethane accounts for approximately 20 per cent of Denmark’s gas consumption, and the aim is for the grid to become totally green by 2035.

Amine scrubber process

“Wärtsilä Biogas Solutions is a market leader offering innovative systems and lifecycle solutions to the gas value chain. Our biogas upgrading plants are based on Wärtsilä’s Puregas CA technology, an amine scrubber process featuring the lowest operating costs. We have enjoyed a long and constructive relationship with Nature Energy, and are proud to have again been chosen for these latest projects,” commented Arne Jakobsen, General Manager for Biogas Solutions at Wärtsilä Gas Solutions.

“The amine scrubber technology is both robust and reliable, providing very low methane slip and cost-effective operating performance. We have worked often with Wärtsilä and are confident, therefore, that the plants will be completed on time and will operate with the usual efficiency,” said Jesper Bundgaard, Executive VP at Nature Energy.

Slated for operation in 2022

The two plants are to be installed in the towns of Kvaers and Kong, with each plant upgrading more than 40 million Nm3 of biogas each year. This will deliver some 470GWh of green gas energy, equivalent to providing the fuel for more than 45,000 cars. It is expected that the plants will begin injecting biomethane to the Danish gas grid in 2022.

Wärtsilä Gas Solutions is a market leader with innovative systems and lifecycle solutions for the gas value chain. Its main focus areas are handling of gas in seaborne transport (storage, fuel, transfer and BOG management), gas to power, liquefaction and biogas solutions. The firm helps its customers on the journey towards a sustainable future through focus on lifecycle, innovation and digitalisation.