Cofermentor, bio-ethanol installation, and algae cultivation pond utilise each other’s residual heat

In addition to the possibility of additional income, it would enable the agrarian sector to contribute to the solution of the climate problem. The disadvantage to fermenting manure and other organic material is that a great deal of energy is lost as heat. The EnergieRijk project utilises this residual heat to increase both the economic and the ecological profitability of the fermenting process.

Wageningen UR’s Application Centre for Renewable RESources (ACRRES)  (website in Dutch only), in cooperation with Zeafuels and Eneco, has developed a concept in which a cofermentor is connected to a bio-ethanol installation and an algae pond. These installations for generating sustainable energy and producing biofuels will utilise each other’s residual heat and waste products. The ultimate goal of EnergieRijk is to close regional biobased cycles. These sustainable cycles optimally utilise plant and animal waste material, called biomass, as a food source, raw material, and energy source. EnergieRijk has three component projects:

• Cofermentation
• Bio-ethanol production
• Algae cultivation

Cofermentation

When animal manure is fermented, biogas is generated by the organic substances in the manure. This mixture of methane and CO2 produces electricity when it is burned in a cogeneration plant. Adding green maize or another plant material to the manure before fermentation generates even more energy. This process is called cofermentation. Fermentation and cofermentation also release large amounts of heat. Some of this heat is used to warm the fermentor installation. The rest is lost. In the Cofermentation component project (website in Dutch only), the residual heat from the fermentor is used in the production of bio-ethanol and algae.

Bio-ethanol

As a result of the rising prices for fossil fuels and the European guidelines for reduced CO2 emissions, the demand for the production of biofuels is increasing sharply. Bio-ethanol is one of these biofuels. In combination with petrol, it can be used in petrol cars with no problems, Maize, wheat, and sugar beet are very suitable for producing bio-ethanol because of their high levels of starches and sugars. A yeast can transform these crops into bio-ethanol. In the Bio-ethanol production component project ACRRES  connects a cofermentor to a bio-ethanol installation. In this way, the ethanol production process can utilise the residual heat from the fermentation. In turn, the cofermentor can ferment the waste from the ethanol production and turn it into energy.

Algae pond

Algae reproduce quickly, do not need fertile ground, and have several applications. A variety of substances can be derived from algae, including vitamins, medicinal substances, pigments, and oils. Biodiesel from algae is very environmentally friendly and contributes to reduced greenhouse gas emissions. In theAlgae cultivation component project (website in Dutch only), ACRRES researchers connect an algae pond with a cofermentor. In their growth process, the algae make good use of the residual heat and waste products from the cofermentor. Investigations are being made into the most economically advantageous and environmentally friendly method for cultivating algae. The algae pond will be built in the second half of 2010. The test fermentor and bio-ethanol installation are already operational. The first research results from this will be complete in the middle of summer 2010.

Links:

• Application Centre for Renewable RESources (ACRRES)