Nutrient Recovery

Combination of Nutrient Recovery and Ethanol

Separation og Ethanol - Flowsheet

Energy production from Renew Energy’s biorefinery protects traditional ethanol plants against fluctuations of energy expenses from fossil fuels.

1st and 2nd generation ethanol plants have positive as well as negative impact on the local environment and gross energy balance. Biofuels are produced for the transport sector. However, large amounts of fossil fuel are used for the production. The negative impact will be greatly reduced, if the ethanol plant is combined with Renew Energy’s biogas/nutrient recovery plant: water can be reused, the plant produces energy for its own consumption, and the plant recovers the nutrients which can be used as fertilizers in the agricultural sector.

The net environmental benefit from combining ethanol and biogas plants will be many times greater, and the use of fossil fuels can be avoided. Besides, surplus power can be sold to the grid as green energy.


Renew Energy’s biorefinery in combination with ethanol plants can offer:

  • Energy efficient new ethanol plants.

  • Retrofit, efficiency improvement or expansion of existing ethanol plants, where the owners wish to optimize the operating economy and improve environmental issues.

  • Improvement of existing distilleries through energy savings and reduced environmental issues.

  • Production of fertilizer products which can be applied to the crops grown for ethanol production.

Combination Possibilities Ethanol and Biogas

  • All residual products (whole stillage) from the ethanol plant are used for biogas production. The plant is self-sufficient in energy and a net exporter of power for sale.

  • All residual products are centrifuged. The fiber fraction or distillers grain (DWG) is used for animal feed with or without drying. The thin fraction (thin stillage) is used for biogas production, and the plant will be partly self-sufficient in energy. At the same time, the plant can deliver large quantities of water back to the ethanol plant.

  • Biomass such as livestock manure, organic waste or residual products from biodiesel production can be treated in the biogas plant together with whole stillage or thin stillage. Thus, the energy production can be optimized.