biogas upgrading system

Dutch company, Ecofuels, wanted to turn biogas from
organic waste into a sustainable energy source.
With Pentair® Biogas Upgrading Solutions, Ecofuels realized
their ambition.

THE STORY OF ECOFUELS
Founded in 2006, Ecofuels is an industrial, biochemical production
company, originally initiated by Dutch company Laarakker
Groenteverwerking B.V., a specialist in cultivating, processing and selling
vegetables, and Indaver Nederland B.V., an industrial and household
waste specialist.

Laarakker Groenteverwerking grows 110,000 tons of vegetables annually
on 3,500 hectares (8,650 acres) and sells them to producers of canned,
frozen and juice products. Indaver Nederland is a vegetable waste
management specialist that processes 400,000 tons of vegetable
waste to compost each year which is sold as fertilizer to agricultural and
gardening enterprises.

In 2006, Ecofuels started two biogas fermenters at its premises in Well,
Limburg, The Netherlands.

MAINTAINING SUSTAINABLE PRACTICES
Sustainable resource management and renewable energy are
integral parts of Ecofuels’ philosophy.
In 2011, Ecofuels decided to go one step further by expanding the capacity
of their existing digesters to produce 650-700 m3
 of biogas per hour.
They wanted to start converting this biogas into biomethane, which is
compatible for use in the national grid network due to its near-pure methane
composition.

When seeking a biogas upgrading partner, Ecofuels opted for Pentair
Biogas Upgrading System, Pentair® BioComplete. The Biogas Upgrading
System offers two distinct advantages:

∙ It provides a comprehensive approach for turning waste streams into
 sustainable energy solutions.
∙ The by-product, liquid CO2, can be used as a commercially viable product
 rather than released into the atmosphere.

Pentair BioComplete splits Ecofuels’ biogas into a methane stream and a CO2 off-gas stream. The raw biogas first goes through a scrubber and an activated carbon filter to remove impurities. Then a compressor provides the pressure needed to push the biogas through the membrane unit, where the primary separation process occurs. The off gas from the first membrane step goes to the CO2 recovery plant, which is pressurized to 17.5 bar and cleaned in an activated carbon filter/dryer. The gas is stripped and liquefied by cooling to -24°C, while methane is fed back to the membrane unit.

The Pentair BioComplete plant at Ecofuels comprises of membrane and cryogenic technology. It produces 650-700 Nm3 /h of biogas which is processed into 340-360 Nm3 /h of biomethane or 2.800.000 m3 of biomethane per year 2 . Furthermore, 2.000 tons of renewable liquid CO2 are recovered per year.

THE FUTURE FOR ECOFUELS 

The resulting biomethane is fed into the national grid. Ecofuels receives the feed-in remuneration that is prescribed in the Dutch Renewable Energy Regulation. The CO2 by-product is used across a variety of applications such as gaseous fertilizer in greenhouses, as a cooling agent in industrial applications and to produce dry ice which Ecofuels can use as an additional revenue stream