Future biogas plants - Interaction between slurry seperation and biogas production

The following work tasks have been finished: 1) Identification of technologies for pre-treatment, separation and recirculation. 2) Formulation of new technical concepts and their integration with agriculture. 3) Formulation of full-scale systems. 4) Development of veterinary risk model for assessment of transfer of pathogens. 5) Development of an economic model for comparative analyses of concepts and scenarios. 6) Assessment of environmental impacts and socio economic consequences. As a part of the project laboratories and pilot tests have been undertaken to estimate input-output relations in wet-oxidation, pressure boiling and re-circulation of fibre-fractions. The main conclusions from the economic analyses is that it is possible by on farm separation and pre-treatment at the biogas plant to improve economic performance of the system as a whole and thereby decrease the need for admixture of organic waste, or other high yielding biomasses. On the other hand the increase in economic results does not enable plants to be economic feasible solely on animal manure. The new plant concepts might give agriculture advantages in relation to handle surpluses of animal manure. The veterinary risk assessments show that a good effects can be archived from gasification and the new technologies on the condition that normal rules for transport and handling of slurry are fulfilled