The CO2 released during the burning of biomass equals the quantity the plant absorbed during its growth. Renewable biomass in turn absorbs the released quantity of CO2. It is therefore a closed CO2 cycle.

The climate balance of the various biofuels depends on how energy-intensive the cultivation is (e.g. fertilisers, ploughing) and how complicated the transport and conversion are to organise (efficiency e.g. of a biorefinery). From the view of the climate balance therefore, closed, decentralised cycles in which native energy crops are efficiently used are the optimum solution. New methods of biofuel production (BtL - biomass-to-liquid) can further improve the energy and climate balance.

Vegetable oil and rapeseed meal are produced from rap in the oil mill. In the biodiesel plant the vegetable oil is processed to form biodiesel, which can be used as biofuel in cars, trucks, aircraft or ships. Renewable rape re-absorbs the CO2 emitted. The rapeseed meal produced in the oil mill is used as a protein feedstuff in livestock farming. Slurry produced there can in turn be used as an energy source in digesters. Fermentation residues can then be used as fertiliser for the growing of rape. However, additional process energy, e.g. bioenergy, has to be added from outside for the rape cultivation and for operation of the biodiesel plant.

 

Away from oil

Biowaste	Biodiesel
Slurry	Vegetable oil
Rape	Bioethanol
Maize	Biogas
Grain	Synthetic biofuel (BtL)
Sugar beet
Wood