Details

Autor(en) / Beteiligte

• Olkiewicz, Magdalena
• Caporgno, Martin Pablo
• Fortuny, Agustí
• Stüber, Frank
• Fabregat, Azael
• Font, Josep
• Bengoa, Christophe

Titel

Direct liquid–liquid extraction of lipid from municipal sewage sludge for biodiesel production

Ist Teil von

• Fuel processing technology, 2014-12, Vol.128, p.331-338

Ort / Verlag

Amsterdam: Elsevier B.V

Erscheinungsjahr

2014

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Municipal sludge from wastewater treatment plants is a promising lipid feedstock for biodiesel production as it contains a significant amount of lipids. However, the energy necessary to remove its high water content is a major inconvenience for scaling up because of the high associated cost. In addition, the expensive conventional sludge drying methods are not effective enough for lipid recovery, thus reducing the potential biodiesel production. This study explores an alternative method, the direct sequential liquid–liquid extraction, which was performed in a batch mixer–settler reactor at room temperature, using hexane as a solvent, after previous sludge acidification showed significant increase in the lipid efficiency. The optimisation study demonstrated that, after three stages, 91% of lipid from primary sludge was recovered. The optimised extraction gave slightly higher lipid (27%, dry sludge) than the standard method (25%, dry sludge), supporting the suitability of the proposed process. Finally, this work demonstrates that the residual lipid-extracted sludge is still a good feedstock for energy production via anaerobic digestion. Anyway, the economic and environmental aspects of biodiesel production from sewage sludge could be improved. [Display omitted] •Sludge drying methods affect the lipid yield, reducing biodiesel production.•Direct lipid extraction from liquid sludge was successfully developed.•The method gave high lipid and biodiesel yields after sludge acidification.•This alternate extraction method avoids the expensive sludge drying process.•Residual lipid-extracted sludge is still a good biomass for biogas production.