Hitachi Zosen Inova BioMethan GmbH (HZIB), the biogas upgrading arm of Switzerland-headed energy from clean-tech providers Hitachi Zosen Inova (HZI) has announced that it has been awarded a contract to build a membrane plant in Denmark that will upgrade 900 Nm³ per hour of raw biogas to produce biomethane for injection into the grid. The installation will be producing renewable natural gas (RNG) by the end of the year and marks the company's first project in Denmark.

The project client is a local agricultural business near Vrå in northern Jutland, involved in both arable and livestock farming. Primarily using agricultural by-products such as slurry, pig manure and ground litter with straw, but also glycerine, olive pomace, and other plant matter, biogas is currently upgraded in an existing installation to make biomethane for injection into the local gas grid.
Now since the biogas plant has secured a supply of substrate to increase biogas production, the owner has decided to build a second upgrading plant.
The planned new plant to be built by HZI BioMethan (HZIB) is designed to treat 900 Nm³ of raw biogas per hour. The carbon dioxide (CO2) in this biogas will be separated out by membrane-based gas permeation in 6-inch modules to produce around 4 million Nm³ of biomethane per annum.
The first gas is scheduled to be injected into the grid by the end of 2019. The current detail engineering phase will be followed by implementation planning, followed by works production. At the end of October, the plant will be erected on the client’s site so that commissioning can be completed by the end of December.
Demanding project delivery
According to HZIB, the scope of supply includes an overhaul of the entire biomethane generation technology already on the site. Energy-efficient precleaning equipment is to be installed upstream of the existing gas upgrading facility already in operation to augment and optimise its existing precleaning capabilities.
This includes a gas scrubber, which removes ammonia (NH3) and water-soluble volatile organic compounds (VOCs) in the precleaning phase along with a process for recovering heat from the stream of raw gas at the precleaning phase, feeding it back into the fermentation process using a heat pump.
To meet this requirement, HZI BioMethan worked with its Scandinavian distribution partner, Nærenergi, a compressor specialist with expertise in the field of compressed natural gas (CNG) technology and other parts of the renewable energy sector that has delivered various projects in Norway and Denmark.
Biogas upgrading helps Danish energy transition
Denmark’s goal is to transition the entire energy supply (electricity, heat, and transportation) to renewable resources by 2050. While this will be done primarily using wind energy, treating biomass to produce biogas and biomethane is gaining in importance.
Agriculture is a major industry in Denmark that provides plenty of substrate for fermentation in biogas plants. Upgraded to natural gas, this produces a fuel of unparalleled flexibility that can be used for anything from generating electricity and heat to fuelling vehicles.
By recycling biogenous residues, farmers can help achieve a successful energy transition, manage resources sustainably, and create an additional source of revenue for themselves, commented Jan Ludeloff, HZI BioMethan’s sales manager for northern Europe, who initiated the project in partnership with Nærenergi.