BioBos (production of biodiesel from STEP sludge)

About the project

Forecasts show that the number of treatment stations and the quantity of sludge treated will increase in the coming years due to growing industrialisation and urbanisation. The treatment of sludge and its elimination will undoubtedly present environmental challenges. An alternative to the elimination methods currently used (incineration, landfill, agricultural spreading) is to use the lipids present in the sludge as a raw material for the production of biodiesel. The conversion of lipids present in biodiesel sludge requires a specific conversion process. This strategy has several benefits: reduction of the volume of sludge, waste recovery, source of cheap lipids and no competition with agriculture. In addition, the recovery of waste after extraction is evaluated via different channels to optimise the profitability of the process as much as possible. European directive 2009/28/EC sets an objective for a 20% reduction in greenhouse gases and the replacement of 20% of traditional fuels with renewable energy in total energy consumption in the EU by 2020. In terms of biofuels, the European Commission requires them to represent 10% of use by 2020. This project has two objectives: reducing the volume of sludge with waste recovery and producing biodiesel.


    • Evaluation of the lipid content in sludge from stations in the Walloon region
    • Optimisation of the lipid extraction method with a view to applying this on an industrial scale
    • Evaluation of the conversion of lipids obtained into biodiesel
    • Optimisation of the conversion of lipids into biodiesel using a pilot reactor
    • Characterisation of the biodiesel by applying standard EN 14214:2012
    • Evaluation of the cost on an industrial scale
    • Evaluation of the different approaches for the optimal recovery of the extraction residue

Scientific approach

    • Determination of the lipid levels in sludge and the evaluation/optimisation of the extraction method
    • Preliminary biodiesel conversion tests at laboratory level
    • Development of a pilot reactor for obtaining the first performance parameters
    • Optimisation of the reaction for producing biodiesel
    • Application of standard EN 14214:2012 (physiochemical biodiesel analysis)
    • Evaluation of the process’ energy consumption and energy integration
    • Evaluation of the complementarity possibility with the SLOG project currently being developed
    • Determination of the optimal recovery of the final residue:
      o Evaluation of energy recovery + ash recovery (CRM-ETP)
      o Evaluation of the recovery of agricultural residue (CRA-W)
      o Evaluation of the environmental impact of spreading the extraction residue on soil