Wärtsilä has engineered, delivered, and installed the biogas upgrading solution to a new biogas 17 tpd liquefaction plant in Hjørring, Denmark. The contract was awarded to Wärtsilä in 2022, and the official start-up took place in June 2023.
The facility is one of two biogas plants owned and operated by GrønGas A/S in Denmark. The other plant, located in Vrå, also features a Wärtsilä biogas upgrading solution. The plant in Hjørring has a production capacity of more than 6200 tpy of bio-LNG. Denmark is a world leader in biomethane development, and these plants are seen as being an important element in securing the country's green energy future.
The Wärtsilä Mixed Refrigerant (MR) liquefaction unit alone has an exceptionally low power consumption of <0.75 kWh/kg of bio-LNG liquefied. This, in combination with Wärtsilä’s Puregas CA technology for biogas upgrading and polishing, with a total methane loss of less than 0.1%, makes it extremely energy efficient. The Puregas CA at Hjørring is equipped with the patented VAC (vacuum) option that offers greater flexibility in delivering heat to the upgrader, heat sources down to a temperature of 95°C are possible to use.
The Hjørring plant transforms manure-based biogas into bio-LNG, representing annual carbon dioxide savings of approximately 41 000 tpy when replacing natural gas.
“Biogas is a renewable energy source that can be stored, and it is of great significance as Denmark seeks to combat the effects of climate change. The trust and efficiency of the Wärtsilä solutions selected for our two sites is central to these efforts,” said Allan K. Olesen, CEO, GrønGas.
“We at Wärtsilä are proud to contribute to a decarbonised future, and we congratulate GrønGas on the opening of this important new plant. Their plants are doing a great job in reducing greenhouse gas emissions, and we are pleased to support them. Our biogas solutions are designed to take advantage of energy integration, which optimises their performance and minimises the overall energy costs,” added Goran Gajski, Sales Manager Biogas, Denmark/Norway, Wärtsilä Gas Solutions.
The full Wärtsilä scope for the Hjørring installation includes the Puregas CA biogas upgrading and polishing unit, with the patented Wärtsilä VAC solution, the liquefaction unit based on MR technology, a 250 m3 bio-LNG storage tank, bio-LNG export station to tank-truck, and instrument air.