Functionality tests of the BiFFiO pilot plant
After solving different technical problems that where related to the small size of the pilot plant, we have now successfully completed most of the planned test scenarios that include:
- Scenarios with different mixes of marine aquaculture waste and cattle manure
- Scenarios with different mixes of freshwater aquaculture waste and cattle manure
- Scenarios with freshwater aquaculture sludge, cattle manure & cuttings
During all scenarios the operation of all four reactors has been comparatively stable. The diagram below shows the methane concentration in the produced biogas in one of the four reactors during 4 different test scenarios. The methane concentration varies between about 40-80 %.
Furthermore nearly all analysis regarding nutrient, heavy metals and other parameters of the different mixes of the substrate have been performed. At present, we are evaluating the obtained data for the gas production and the feedstock analysis.
Parallel with the trials of the pre-processing and the and the anaerobic digestion, assessment of posttreatment options and storage of digestate has been performed. Further to this, a laboratory scale posttreatment device based on electroflocculation combined with ultrasonic unit has been developed. This system is under functionality tests to evaluate its performance in relation to liquid-solid separation, nutrient recovery inn the separated fractions and ultra hygienisation of the digestate.
In order to evaluate the fertilizer value of the digestate from the different scenarios with recovery of valuable nutrients including phosphorous, nitrogen and potassium a series of growth trials different plant species have been undertaken in a large horticultural polythene tunnel built adjacent to the pilot plant. The growth trials are now in their final phase and obtained results are under evaluation.